Partial wave analysis using graphics processing units
Energy Technology Data Exchange (ETDEWEB)
Berger, Niklaus; Liu Beijiang; Wang Jike, E-mail: nberger@ihep.ac.c [Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Lu, Shijingshan, 100049 Beijing (China)
2010-04-01
Partial wave analysis is an important tool for determining resonance properties in hadron spectroscopy. For large data samples however, the un-binned likelihood fits employed are computationally very expensive. At the Beijing Spectrometer (BES) III experiment, an increase in statistics compared to earlier experiments of up to two orders of magnitude is expected. In order to allow for a timely analysis of these datasets, additional computing power with short turnover times has to be made available. It turns out that graphics processing units (GPUs) originally developed for 3D computer games have an architecture of massively parallel single instruction multiple data floating point units that is almost ideally suited for the algorithms employed in partial wave analysis. We have implemented a framework for tensor manipulation and partial wave fits called GPUPWA. The user writes a program in pure C++ whilst the GPUPWA classes handle computations on the GPU, memory transfers, caching and other technical details. In conjunction with a recent graphics processor, the framework provides a speed-up of the partial wave fit by more than two orders of magnitude compared to legacy FORTRAN code.
Barrelet zeros in partial wave analysis
International Nuclear Information System (INIS)
Baker, R.D.
1976-01-01
The formalism of Barrelet zeros is discussed. Spinless scattering is described to introduce the idea, then the more usual case of 0 - 1/2 + → 0 - 1/2 + scattering. The zeros are regarded here only as a means to an end, viz the partial waves. The extraction of these is given in detail, and ambiguities are discussed at length. (author)
SLAC three-body partial wave analysis system
International Nuclear Information System (INIS)
Aston, D.; Lasinski, T.A.; Sinervo, P.K.
1985-10-01
We present a heuristic description of the SLAC-LBL three-meson partial wave model, and describe how we have implemented it at SLAC. The discussion details the assumptions of the model and the analysis, and emphasizes the methods we have used to prepare and fit the data. 28 refs., 12 figs., 1 tab
Poles of the Zagreb analysis partial-wave T matrices
Batinić, M.; Ceci, S.; Švarc, A.; Zauner, B.
2010-09-01
The Zagreb analysis partial-wave T matrices included in the Review of Particle Physics [by the Particle Data Group (PDG)] contain Breit-Wigner parameters only. As the advantages of pole over Breit-Wigner parameters in quantifying scattering matrix resonant states are becoming indisputable, we supplement the original solution with the pole parameters. Because of an already reported numeric error in the S11 analytic continuation [Batinić , Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.57.1004 57, 1004(E) (1997); arXiv:nucl-th/9703023], we declare the old BATINIC 95 solution, presently included by the PDG, invalid. Instead, we offer two new solutions: (A) corrected BATINIC 95 and (B) a new solution with an improved S11 πN elastic input. We endorse solution (B).
Direct Calculation of the Scattering Amplitude Without Partial Wave Analysis
Shertzer, J.; Temkin, A.; Fisher, Richard R. (Technical Monitor)
2001-01-01
Two new developments in scattering theory are reported. We show, in a practical way, how one can calculate the full scattering amplitude without invoking a partial wave expansion. First, the integral expression for the scattering amplitude f(theta) is simplified by an analytic integration over the azimuthal angle. Second, the full scattering wavefunction which appears in the integral expression for f(theta) is obtained by solving the Schrodinger equation with the finite element method (FEM). As an example, we calculate electron scattering from the Hartree potential. With minimal computational effort, we obtain accurate and stable results for the scattering amplitude.
Baryon Spectroscopy Through Partial-Wave Analysis and Meson Photoproduction
International Nuclear Information System (INIS)
Manley, D. Mark
2016-01-01
The principal goal of this project is the experimental and phenomenological study of baryon spectroscopy. The PI's group consists of himself and three graduate students. This final report summarizes research activities by the PI's group during the period 03/01/2015 to 08/14/2016. During this period, the PI co-authored 11 published journal papers and one proceedings article and presented three invited talks. The PI's general interest is the investigation of the baryon resonance spectrum up to masses of ~ 2 GeV. More detail is given on two research projects: Neutral Kaon Photoproduction and Partial-Wave Analyses of γp → η p, γn → η n, and γp → K"+ Λ.
Baryon Spectroscopy Through Partial-Wave Analysis and Meson Photoproduction
Energy Technology Data Exchange (ETDEWEB)
Manley, D. Mark [Kent State Univ., Kent, OH (United States)
2016-09-08
The principal goal of this project is the experimental and phenomenological study of baryon spectroscopy. The PI's group consists of himself and three graduate students. This final report summarizes research activities by the PI's group during the period 03/01/2015 to 08/14/2016. During this period, the PI co-authored 11 published journal papers and one proceedings article and presented three invited talks. The PI's general interest is the investigation of the baryon resonance spectrum up to masses of ~ 2 GeV. More detail is given on two research projects: Neutral Kaon Photoproduction and Partial-Wave Analyses of γp → η p, γn → η n, and γp → K⁺ Λ.
Partial wave analysis for folded differential cross sections
Machacek, J. R.; McEachran, R. P.
2018-03-01
The value of modified effective range theory (MERT) and the connection between differential cross sections and phase shifts in low-energy electron scattering has long been recognized. Recent experimental techniques involving magnetically confined beams have introduced the concept of folded differential cross sections (FDCS) where the forward (θ ≤ π/2) and backward scattered (θ ≥ π/2) projectiles are unresolved, that is the value measured at the angle θ is the sum of the signal for particles scattered into the angles θ and π - θ. We have developed an alternative approach to MERT in order to analyse low-energy folded differential cross sections for positrons and electrons. This results in a simplified expression for the FDCS when it is expressed in terms of partial waves and thereby enables one to extract the first few phase shifts from a fit to an experimental FDCS at low energies. Thus, this method predicts forward and backward angle scattering (0 to π) using only experimental FDCS data and can be used to determine the total elastic cross section solely from experimental results at low-energy, which are limited in angular range.
DEFF Research Database (Denmark)
Ilic, C; Chadwick, A; Helm-Petersen, Jacob
2000-01-01
, non-phased locked methods are more appropriate. In this paper, the accuracy of two non-phased locked methods of directional analysis, the maximum likelihood method (MLM) and the Bayesian directional method (BDM) have been quantitatively evaluated using numerical simulations for the case...... of multidirectional waves with partial reflections. It is shown that the results are influenced by the ratio of distance from the reflector (L) to the length of the time series (S) used in the spectral analysis. Both methods are found to be capable of determining the incident and reflective wave fields when US > 0......Recent studies of advanced directional analysis techniques have mainly centred on incident wave fields. In the study of coastal structures, however, partially reflective wave fields are commonly present. In the near structure field, phase locked methods can be successfully applied. In the far field...
Nucleon-nucleon partial-wave analysis to 1100 MeV
International Nuclear Information System (INIS)
Arndt, R.A.; Hyslop, J.S. III; Roper, L.D.
1987-01-01
Comprehensive analyses of nucleon-nucleon elastic-scattering data below 1100 MeV laboratory kinetic energy are presented. The data base from which an energy-dependent solution and 22 single-energy solutions are obtained consists of 7223 pp and 5474 np data. A resonancelike structure is found to occur in the 1 D 2 , 3 F 3 , 3 P 2 - 3 F 2 , and 3 F 4 - 3 H 4 partial waves; this behavior is associated with poles in the complex energy plane. The pole positions and residues are obtained by analytic continuation of the ''production'' piece of the T matrix obtained in the energy-dependent solution. The new phases differ somewhat from previously published VPIandSU solutions, especially in I = 0 waves above 500 MeV, where np data are very sparse. The partial waves are, however, based upon a significantly larger data base and reflect correspondingly smaller errors. The full data base and solution files can be obtained through a computer scattering analysis interactive dial-in (SAID) system at VPIandSU, which also exists at many institutions around the world and which can be transferred to any site with a suitable computer system. The SAID system can be used to modify solutions, plan experiments, and obtain any of the multitude of predictions which derive from partial-wave analyses of the world data base
Partial wave analysis of anti pp → anti ΛΛ
International Nuclear Information System (INIS)
Bugg, D.V.
2004-01-01
A partial wave analysis of PS185 data for anti pp → anti ΛΛ is presented. A 3 S 1 cusp is identified in the inverse process anti ΛΛ→ anti p p at threshold, using detailed balance to deduce cross sections from anti pp → anti ΛΛ. Partial wave amplitudes for anti pp 3 P 0 , 3 F 3 , 3 D 3 and 3 G 3 exhibit a behaviour very similar to resonances observed in Crystal Barrel data. With this identification, the anti pp → anti ΛΛ data then provide evidence for a new I=0, J PC =1 - resonance with mass M = 2290 ±20 MeV, Γ= 275 ±35 MeV, coupling to both 3 S 1 and 3 D 1 . (orig.)
Partial wave analysis of KKPI system in D and E/IOTA region
International Nuclear Information System (INIS)
Chung, S.U.; Fernow, R.; Kirk, H.
1985-01-01
A partial wave analysis and a Dalitz plot analysis of high-statistics data from reaction π - p → K + K/sub S/π - n at 8.0 GeV/c show that the D(1285) is a J/sup PG/ = 1 ++ state and the E(1420) a J/sup PG/ = 0 -+ state both with a substantial deltaπ decay mode. The 1 ++ K*anti K wave exhibits a rapid rise near threshold but no evidence of a resonance in the E region. The assignment of J/sup PG/ = O -+ to the E is confirmed from a Dalitz-plot analysis of the reaction pp → K + K/sub S/π - X 0 . 11 refs., 5 figs
Partial wave analysis of the 18O(p,α0)15N reaction
International Nuclear Information System (INIS)
Wild, L.W.J.; Spicer, B.M.
1979-01-01
A partial wave analysis of the differential cross sections for the 18 O(p,α 0 ) 15 N reaction has been carried out applying the formalism of Blatt and Biedenharn (1952), made specific for this reaction. The differential cross sections, measured at 200 keV intervals from 6.6 to 10.4 MeV bombarding energy, were subjected to least-squares fitting to this specific analytic expression. Two resonances were given by the analysis, the 19 F states being at 14.71+-0.07 MeV (1/2 - ) and 14.80 + 0.07 MeV (1/2) +
On continuous ambiguities in model-independent partial wave analysis - 1
International Nuclear Information System (INIS)
Nikitin, I.N.
1995-01-01
A problem of amplitude reconstruction in terms of the given angular distribution is considered. Solution of this problem is not unique. A class of amplitudes, correspondent to one and the same angular distribution, forms a region in projection onto a finite set of spherical harmonics. An explicit parametrization of a boundary of the region is obtained. A shape of the region of ambiguities is studied in particular example. A scheme of partial-wave analysis, which describes all solutions in the limits of the region, is proposed. 5 refs., 5 figs
Partial wave analysis of ι/η(1430) from DM2
International Nuclear Information System (INIS)
Augustin, J.E.; Cosme, G.; Couchot, F.; Fulda, F.; Grosdidier, G.; Jean-Marie, B.; Lepeltier, V.; Mane, M.; Szklarz, G.; Jousset, J.; Ajaltouni, Z.; Falvard, A.; Michel, B.; Montret, J.C.
1989-12-01
A Partial Wave Analysis of the ι/η (1430) region from the study of the radiative decays J/Ψ → γ K S 0 K ± π -+ and J/Ψ → γ K ± K -+ π 0 is presented. Pseudoscalar dominance appears clearly with two dynamical components. The main one which proceeds via δ/a 0 (980) π is centered at 1460 MeV/c 2 , while the second one with K*(892) K dynamics is peaked at a lower mass (1420 MeV/c 2 ) close to its kinematical threshold. In addition, the higher part of the mass spectrum contains a significant contribution from the 1 ++ K*(892)K wave
Partial wave analysis of DM2 data in the η(1430) energy range
International Nuclear Information System (INIS)
Augustin, J.E.; Cosme, G.; Couchot, F.; Fulda, F.; Grosdidier, G.; Jean-Marie, B.; Lepeltier, V.; Szklarz, G.; Bisello, D.; Busetto, G.; Castro, A.; Pescara, L.; Sartori, P.; Stanco, L.; Ajaltouni, Z.; Falvard, A.; Jousset, J.; Michel, B.; Montret, J.C.
1990-10-01
Partial Wave Analysis of the J/ψ → γK S 0 K ± π -+ , γK ± K -+ π 0 decays in the ι/η(1430) mass range shows a clear pseudoscalar dominance, with two dynamical components. The main one, centered at ∼ 1460 MeV/c 2 , proceeds via a 0 (980)π dynamics, while the second one with K*(892)K dynamics is peaked at ∼ 1420 MeV/c 2 , close to its threshold. In addition, the higher part of the mass spectrum contains a significant contribution from the 1 ++ K*(892)K wave. In the PWA of the J/ψ → γηπ + π - channel a resonant a 0 π production is observed slightly below 1400 MeV/c 2
PyPWA: A partial-wave/amplitude analysis software framework
Salgado, Carlos
2016-05-01
The PyPWA project aims to develop a software framework for Partial Wave and Amplitude Analysis of data; providing the user with software tools to identify resonances from multi-particle final states in photoproduction. Most of the code is written in Python. The software is divided into two main branches: one general-shell where amplitude's parameters (or any parametric model) are to be estimated from the data. This branch also includes software to produce simulated data-sets using the fitted amplitudes. A second branch contains a specific realization of the isobar model (with room to include Deck-type and other isobar model extensions) to perform PWA with an interface into the computer resources at Jefferson Lab. We are currently implementing parallelism and vectorization using the Intel's Xeon Phi family of coprocessors.
General partial wave analysis of the decay of a hyperon of spin 1/2
International Nuclear Information System (INIS)
Lee, T.D.; Yang, C.N.
1983-01-01
This note is to consider the general problem of the decay of a hyperon of spin 1/2 into a pion and a nucleon under the general assumption of possible violations of parity conservation, charge-conjugation invariance, and time-reversal invariance. The discussion is in essence a partial wave analysis of the decay phenomena and is independent of the dynamics of the decay. Nonrelativistic approximations are not made on either of the decay products. In the reference system in which the hyperon is at rest there are two possible final states of the pion-nucleon system:s/sub 1/2/ and p/sub 1/2/. Denoting the amplitudes of these two states by A and B, one observes that the decay is physically characterized by three real constants specifying the magnitudes and the relative phase between these amplitudes. One of these constants can be taken to be absolute value a 2 + absolute value B 2 , and is evidently proportional to the decay probability per unit time. The other two constants are best defined in terms of experimentally measurable quantities. They discuss three types of experiments: (a) The angular distribution of the decay pion from a completely polarized hyperon at rest. (b) The longitudinal polarization of the nucleon emitted in the decay of unpolarized hyperons at rest. (c) Transverse polarization of the nucleon emitted in a given direction in the decay of a polarized hyperon
Study of NΣ cusp in p+p → p+K{sup +}+Λ with partial wave analysis
Energy Technology Data Exchange (ETDEWEB)
Lu, S.; Muenzer, R.; Epple, E.; Fabbietti, L. [Excellenz Cluster Universe, Technische Universitaet Muenchen (Germany); Ritman, J.; Roderburg, E.; Hauenstein, F. [FZ Juelich (Germany); Collaboration: Hades and FOPI Collaboration
2016-07-01
In the last years, an analysis of exclusive reaction of p+p → p+K{sup +}+Λ has been carried out using Bonn-Gatchina Partial Wave Analysis. In a combined analysis of data from Hades, Fopi, Disto and Cosy-TOF, an energy dependent production process is determined. This analysis has shown that a sufficient description of the p+p → p+K{sup +}+Λ is quite challenging due to the presence of resonances N* and interference, which requires Partial Wave Analysis. A pronounced narrow structure is observed in its projection on the pΛ-invariant mass. This peak structure, which appears around the NΣ threshold, has a strongly asymmetric structure and is interpreted a NΣ cusp effect. In this talk, the results from a combined analysis will be shown, with a special focus on the NΣ cusp structure and a description using Flatte parametrization.
Wave Partial Differential Equation
Szöllös, Alexandr
2009-01-01
Práce se zabývá diferenciálními rovnicemi, jejich využitím při analýze vedení, experimenty s vedením a možnou akcelerací výpočtu v GPU s využitím prostředí nVidia CUDA. This work deals with diffrential equations, with the possibility of using them for analysis of the line and the possibility of accelerating the computations in GPU using nVidia CUDA. C
Model-independent partial wave analysis using a massively-parallel fitting framework
Sun, L.; Aoude, R.; dos Reis, A. C.; Sokoloff, M.
2017-10-01
The functionality of GooFit, a GPU-friendly framework for doing maximum-likelihood fits, has been extended to extract model-independent {\\mathscr{S}}-wave amplitudes in three-body decays such as D + → h + h + h -. A full amplitude analysis is done where the magnitudes and phases of the {\\mathscr{S}}-wave amplitudes are anchored at a finite number of m 2(h + h -) control points, and a cubic spline is used to interpolate between these points. The amplitudes for {\\mathscr{P}}-wave and {\\mathscr{D}}-wave intermediate states are modeled as spin-dependent Breit-Wigner resonances. GooFit uses the Thrust library, with a CUDA backend for NVIDIA GPUs and an OpenMP backend for threads with conventional CPUs. Performance on a variety of platforms is compared. Executing on systems with GPUs is typically a few hundred times faster than executing the same algorithm on a single CPU.
Partial-wave analysis of π-π0π0 events at 18 GeV/c
International Nuclear Information System (INIS)
Brown, D.S.
1998-01-01
A partial-wave analysis has been performed on 170 K π - π 0 π 0 events produced in the reaction π - p→pπ - π 0 π 0 , and the results of the mass-independent fits are presented. The objective was to confirm the existence of the π(1800) and the exotic J PC =1 -+ object, reported by VES. copyright 1998 American Institute of Physics
Almabadi, Huda; Sahay, Peeyush; Nagesh, Prashanth K. B.; Yallapu, Murali M.; Jaggi, Meena; Chauhan, Subhash C.; Pradhan, Prabhakar
Mesoscopic physics based partial wave spectroscopy (PWS) was recently introduced to quantify nanoscale structural disorder in weakly disordered optical media such as biological cells. The degree of structural disorder (Ld) , defined as Ld = 〈 dn2 〉 ×lc is quantified in terms of strength of refractive index fluctuation (〈 dn2 〉) in the system and its correlation length (lc) .With nanoscale sensitivity,Ldhas been shown to have potential to be used in cancer diagnostics. In this work, we analyze the hierarchy of different stages of prostate cancer cells by quantifying their intracellular refractive index fluctuations in terms of Ld parameter. We observe that the increase in tumorigenicity levels inside these prostate cancer cells results in proportionally higherLdvalues. For a weakly disordered optical media like biological cells, this result suggests that the progression of carcinogenesis or the increase in the tumorigenicity level is associated with increased 〈 dn2 〉 and/or lcvalues for the samples. Furthermore, we also examined the applicability of Ld parameter in analyzing the effect of drug on these prostate cancer cells. In accordance with the hypothesis that the cancer cells which survives the drug, becomes more aggressive, we found increased Ldvalues for all the drug resistant prostate cells studied.
Energy Technology Data Exchange (ETDEWEB)
Salgado, Carlos W. [Norfolk State University, Norfolk, VA (United States) and Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Weygand, Dennis P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
2014-04-01
Meson spectroscopy is going through a revival with the advent of high statistics experiments and new advances in the theoretical predictions. The Constituent Quark Model (CQM) is finally being expanded considering more basic principles of field theory and using discrete calculations of Quantum Chromodynamics (lattice QCD). These new calculations are approaching predictive power for the spectrum of hadronic resonances and decay modes. It will be the task of the new experiments to extract the meson spectrum from the data and compare with those predictions. The goal of this report is to describe one particular technique for extracting resonance information from multiparticle final states. The technique described here, partial wave analysis based on the helicity formalism, has been used at Brookhaven National Laboratory (BNL) using pion beams, and Jefferson Laboratory (Jlab) using photon beams. In particular this report broaden this technique to include production experiments using linearly polarized real photons or quasi-real photons. This article is of a didactical nature. We describe the process of analysis, detailing assumptions and formalisms, and is directed towards people interested in starting partial wave analysis.
An energy dependent partial wave analysis of π+ p→ K+ σ+ between threshold and 2.35 GeV
International Nuclear Information System (INIS)
Candlin, D.J.; Lowe, D.C.; Peach, K.J.
1983-11-01
An energy dependent partial wave analysis of the reaction π + p → K + Σ + has been carried out between threshold and 2.35 GeV centre of mass energy using recently published, high statistical precision data. A single solution giving a satisfactory fit to the data has been found. In the region below 2 GeV the resonant features of the solution are compared with the QCD based model of Koniuk and Isgur. Above 2 GeV the states listed in the Particle Data group tables with two or more stars are observed but none of the dubious one star states is confirmed Significant SU(3) breaking is observed in some amplitudes. (author)
Partial-Wave Analysis of Centrally Produced Two-Pseudoscalar Final States in pp Reactions at COMPASS
Austregesilo, Alexander
2014-01-01
COMPASS is a fixed-target experiment at the CERN SPS which focused on light-quark hadron spectroscopy during the data taking periods in 2008 and 2009. A world-leading data set was collected with a 190GeV/c hadron beam impinging on a liquid hydrogen target in order to study, inter alia, the central exclusive production of glueball candidates in the light-meson sector. Especially the double-Pomeron exchange mechanism is well suited for the production of mesons without valence quark content. We select centrally produced systems with two pseudo-scalar mesons in the final state from the COMPASS data set recorded with an incoming proton. The decay of this system is decomposed in terms of partial waves, where particular attention is paid to the inherent mathematical ambiguities of the amplitude analysis. Furthermore, we show that simple parametrisations are able to describe the mass dependence of the fit results with sensible Breit-Wigner parameters.
International Nuclear Information System (INIS)
Forozani, G.
2004-01-01
The magnitude of four independent amplitudes are obtained pion photoproduction in the energy range of 1300 to 2100 MeV incident photon. Different cross section and three polarization parameters are required for such amplitudes reconstruction at different pion scattering angles. Results of the direct amplitudes reconstruction have been compared with the solution of partial wave analysis SM95 and SM00K at all energies. This analysis indicates that we have a fair agreement between the present work and the results of partial wave analysis at many angles
International Nuclear Information System (INIS)
Forozani, G.
2004-01-01
The magnitude of four independent amplitudes are obtained in neutral pion photoproduction in the energy range of 1300 to 2100 MeV incident photon. Differential gross section and three polarization parameters are required for such amplitudes reconstruction at different pion scattering angles. Results of the direct amplitudes reconstruction have been compared with the solution of partial wave analysis SM95 and SM00K at all energies. This analysis indicates that we have a fair agreement between the present work and the results of partial wave analysis at meny angles (Author)
Partial-wave analysis for positronium-xenon collisions in the ultralow-energy region
Shibuya, Kengo; Saito, Haruo
2018-05-01
We propose a method to convert measured positronium annihilation rates in gaseous xenon into total and differential cross sections of positronium-xenon collisions in an ultralow-energy region of less than 80 meV where their experimental determinations as functions of the positronium kinetic energy are extremely difficult. This method makes it possible to determine not only the s -wave collisional parameters but also the p -wave and d -wave parameters. We have found a small positive value of the scattering length, A0=2.06 ±0.10 a0 , which indicates that the positronium-xenon interaction in this energy region is repulsive and suggests that it is dominated by the scattering amplitude of the positron rather than that of the electron. An extrapolation of the analytical result into the experimentally inaccessible energy regions from 80 meV to 1.0 eV indicates that there should not be a Ramsauer-Townsend minimum but rather a peak in the total cross section at an energy of approximately 0.4 eV.
Barrelet zeros and elastic π+p partial waves
International Nuclear Information System (INIS)
Chew, D.M.; Urban, M.
1976-06-01
A procedure is proposed for constructing low-order partial-wave amplitudes from a knowledge of Barrelet zeros near the physical region. The method is applied to the zeros already obtained for elastic π + p scattering data between 1.2 and 2.2 GeV cm energies. The partial waves emerge with errors that are straight-forwardly related to the accuracy of the data and satisfy unitarity without any constraint being imposed. There are significant differences from the partial waves obtained by other methods; this can be partially explained by the fact that no previous partial-wave analysis has been able to solve the discrete ambiguity. The cost of the analysis is much less
Superconformal partial waves in Grassmannian field theories
Energy Technology Data Exchange (ETDEWEB)
Doobary, Reza; Heslop, Paul [Department of Mathematical Sciences, Durham University,South Road, Durham, DH1 3LE United Kingdom (United Kingdom)
2015-12-23
We derive superconformal partial waves for all scalar four-point functions on a super Grassmannian space Gr(m|n,2m|2n) for all m,n. This family of four-point functions includes those of all (arbitrary weight) half BPS operators in both N=4 SYM (m=n=2) and in N=2 superconformal field theories in four dimensions (m=2,n=1) on analytic superspace. It also includes four-point functions of all (arbitrary dimension) scalar fields in non-supersymmetric conformal field theories (m=2,n=0) on Minkowski space, as well as those of a certain class of representations of the compact SU(2n) coset spaces. As an application we then specialise to N=4 SYM and use these results to perform a detailed superconformal partial wave analysis of the four-point functions of arbitrary weight half BPS operators. We discuss the non-trivial separation of protected and unprotected sectors for the 〈2222〉, 〈2233〉 and 〈3333〉 cases in an SU(N) gauge theory at finite N. The 〈2233〉 correlator predicts a non-trivial protected twist four sector for 〈3333〉 which we can completely determine using the knowledge that there is precisely one such protected twist four operator for each spin.
Litchfield, P J; Baillon, Paul; Putzer, A; Schleich, H
1974-01-01
A partial-wave analysis has been carried out on the reaction K/sup -/p to Lambda (1520) pi to K/sup -/p pi /sup 0/. The Sigma (2030) is observed with an amplitude at resonance of 0.14+or-0.03. Evidence is also presented for the formation of the /sup 3///sub 2//sup -/ Sigma (1940). (14 refs).
Partial wave analysis of the π-π-π+ and π-π0π0 systems and the search for a JPC=1-+ meson
International Nuclear Information System (INIS)
Dzierba, A.R.; Mitchell, R.; Scott, E.; Shepherd, M.R.; Smith, P.; Swat, M.; Teige, S.; Szczepaniak, A.P.; Denisov, S.P.; Dorofeev, V.; Kachaev, I.; Lipaev, V.; Popov, A.V.; Ryabchikov, D.I.; Bodyagin, V.A.; Demianov, A.
2006-01-01
A partial wave analysis (PWA) of the π - π - π + and π - π 0 π 0 systems produced in the reaction π - p→(3π) - p at 18 GeV/c was carried out using an isobar model assumption. This analysis is based on 3.0 M π - π 0 π 0 events and 2.6 M π - π - π + events and shows production of the a 1 (1260), a 2 (1320), π 2 (1670), and a 4 (2040) resonances. Results of detailed studies of the stability of partial wave fits are presented. An earlier analysis of 250 K π - π - π + events from the same experiment showed possible evidence for a J PC =1 -+ exotic meson with a mass of ∼1.6 GeV/c 2 decaying into ρπ. In this analysis of a higher statistics sample of the (3π) - system in two charged modes we find no evidence of an exotic meson
Crichton ambiguities with infinitely many partial waves
International Nuclear Information System (INIS)
Atkinson, D.; Kok, L.P.; de Roo, M.
1978-01-01
We construct families of spinless two-particle unitary cross sections that possess a nontrivial discrete phase-shift ambiguity, with in general an infinite number of nonvanishing partial waves. A numerical investigation reveals that some of the previously known finite Crichton ambiguities are merely special cases of the newly constructed examples
Crichton ambiguities with infinitely many partial waves
Atkinson, D.; Kok, L.P.; de Roo, M.
We construct families of spin less two-particle unitary cross sections that possess a nontrivial discrete phase-shift ambiguity, with in general an infinite number of nonvanishing partial waves. A numerical investigation reveals that some of the previously known finite Crichton ambiguities are
ALFVEN WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA
Energy Technology Data Exchange (ETDEWEB)
Soler, R.; Ballester, J. L.; Terradas, J. [Departament de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Carbonell, M., E-mail: roberto.soler@uib.es, E-mail: joseluis.ballester@uib.es, E-mail: jaume.terradas@uib.es, E-mail: marc.carbonell@uib.es [Departament de Matematiques i Informatica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)
2013-04-20
Alfven waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfven waves is affected by the interaction between ionized and neutral species. Here we study Alfven waves in a partially ionized plasma from the theoretical point of view using the two-fluid description. We consider that the plasma is composed of an ion-electron fluid and a neutral fluid, which interact by means of particle collisions. To keep our investigation as general as possible, we take the neutral-ion collision frequency and the ionization degree as free parameters. First, we perform a normal mode analysis. We find the modification due to neutral-ion collisions of the wave frequencies and study the temporal and spatial attenuation of the waves. In addition, we discuss the presence of cutoff values of the wavelength that constrain the existence of oscillatory standing waves in weakly ionized plasmas. Later, we go beyond the normal mode approach and solve the initial-value problem in order to study the time-dependent evolution of the wave perturbations in the two fluids. An application to Alfven waves in the low solar atmospheric plasma is performed and the implication of partial ionization for the energy flux is discussed.
Czech Academy of Sciences Publication Activity Database
Agakishiev, G.; Arnold, O.; Belver, D.; Belyaev, A.; Krása, Antonín; Křížek, Filip; Kugler, Andrej; Sobolev, Yuri, G.; Tlustý, Pavel; Wagner, Vladimír
2015-01-01
Roč. 742, MAR (2015), s. 242-248 ISSN 0370-2693 R&D Projects: GA MŠk LG12007; GA ČR GA13-06759S Institutional support: RVO:61389005 Keywords : kaonic nuclei * anti-kaon-nucleon physics * ppK(-) * low energy * QCD * partial wave analysis Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.787, year: 2015
Litchfield, P J; Baillon, Paul; Albrecht, A; Putzer, A
1974-01-01
A partial-wave analysis has been carried out on the reaction K/sup -/p to K/sup -/ Delta /sup +/(1230) to K/sup -/p pi /sup 0/ in the centre of mass energy region 1915-2170 MeV. The Sigma (2030) is observed with an amplitude at resonance of 0.16+or-0.03. Strong formation of the /sup 3///sub 2//sup -/ Sigma (1940) is also indicated. (9 refs).
Partial Differential Equations and Solitary Waves Theory
Wazwaz, Abdul-Majid
2009-01-01
"Partial Differential Equations and Solitary Waves Theory" is a self-contained book divided into two parts: Part I is a coherent survey bringing together newly developed methods for solving PDEs. While some traditional techniques are presented, this part does not require thorough understanding of abstract theories or compact concepts. Well-selected worked examples and exercises shall guide the reader through the text. Part II provides an extensive exposition of the solitary waves theory. This part handles nonlinear evolution equations by methods such as Hirota’s bilinear method or the tanh-coth method. A self-contained treatment is presented to discuss complete integrability of a wide class of nonlinear equations. This part presents in an accessible manner a systematic presentation of solitons, multi-soliton solutions, kinks, peakons, cuspons, and compactons. While the whole book can be used as a text for advanced undergraduate and graduate students in applied mathematics, physics and engineering, Part II w...
Noboru, HIROSHIGE; Faculty of Economics, Hannan University
1996-01-01
An energy-dependent partial-wave analysis of πd elastic scattering has been performed in the region T_L=65～294 MeV for currently available experimental data, including the recent vector analyzing power iT_ and composite observables τ_. We have obtained a solution which is in good agreement with the experimental data. The ^3P_1,^3P_2,^3D_3 and ^3D_2 amplitudes abtained show counter-clockwise rotating behaviors.
Nakkasyan, A
1975-01-01
Cross sections of the reaction K/sup -/p to pi /sup +/ pi /sup -/ pi /sup 0/ Lambda are determined in a bubble chamber study at 10 incoming beam momenta between 1.425 GeV/c and 1.800 GeV/c. For the subsample K /sup -/p to omega Lambda , cross sections and angular distributions are presented together with their legendre polynomial expansions and those of the single and joint density matrix elements. An energy dependent partial-wave analysis is performed including earlier data. The data is well fitted by constant background amplitudes in the outgoing S, P and D waves plus two I=0 resonances in this region, the well established G/sub 7/ Lambda (2100) and the P/sub 3/ Lambda (1870) . (14 refs).
Numerical method for wave forces acting on partially perforated caisson
Jiang, Feng; Tang, Xiao-cheng; Jin, Zhao; Zhang, Li; Chen, Hong-zhou
2015-04-01
The perforated caisson is widely applied to practical engineering because of its great advantages in effectively wave energy consumption and cost reduction. The attentions of many scientists were paid to the fluid-structure interaction between wave and perforated caisson studies, but until now, most concerns have been put on theoretical analysis and experimental model set up. In this paper, interaction between the wave and the partial perforated caisson in a 2D numerical wave flume is investigated by means of the renewed SPH algorithm, and the mathematical equations are in the form of SPH numerical approximation based on Navier-Stokes equations. The validity of the SPH mathematical method is examined and the simulated results are compared with the results of theoretical models, meanwhile the complex hydrodynamic characteristics when the water particles flow in or out of a wave absorbing chamber are analyzed and the wave pressure distribution of the perforated caisson is also addressed here. The relationship between the ratio of total horizontal force acting on caisson under regular waves and its influence factors is examined. The data show that the numerical calculation of the ratio of total horizontal force meets the empirical regression equation very well. The simulations of SPH about the wave nonlinearity and breaking are briefly depicted in the paper, suggesting that the advantages and great potentiality of the SPH method is significant compared with traditional methods.
Shear Wave Generation by Decoupled and Partially Coupled Explosions
National Research Council Canada - National Science Library
Stevens, Jeffry L; Xu, Heming; Baker, G. E
2008-01-01
The objective of this project is to investigate the sources of shear wave generation by decoupled and partially coupled explosions, and the differences in shear wave generation between tamped and decoupled explosions...
International Nuclear Information System (INIS)
Haas, Florian
2014-01-01
The dynamics of strong interaction in the regime of low energies, i.e. large distances, is still not understood. Given its simplicity the non-relativistic simple quark model (SQM) describes successfully the observed hadronic spectra. QCD-inspired models, however, predict hadronic states where the gluonic content contributes to the hadron quantum numbers. These so-called hybrids cannot be explained within the SQM. A solid experimental proof of the existence of such systems would be the observation of spin-exotic states, with spin-parity quantum numbers, not allowed in the SQM. The study of mesons, the simplest hadrons, permits to gain insight into the realm of strong interaction where hadrons are the relevant degrees of freedom. The most promising spin-exotic meson candidate is the π 1 (1600), which was claimed in several experiments and in particular in data taken during a previous hadron campaign of the COMPASS experiment. The hadron spectroscopy program of the COMPASS experiment at CERN focuses on the investigation of the light-meson spectrum in order to enlighten this rarely understood regime of strong interaction. During the 2008 data taking an unprecedented statistical precision has been reached in peripheral interactions of 190 GeV/c pions with a proton target leading to the π - π - π + final state. A spin-parity analysis in the kinematical region of the squared fourmomentum transfer 0.1≤t'0≤1.0 GeV 2 /c 2 was carried out based on a model of 88 partial waves up to a total angular momentum of 6. Besides the precise determination of properties of known resonances, a new axial-vector state, the a 1 (1420), was observed for the first time in a mass region where neither model nor lattice calculations predict mesons with this quantum numbers. Noteworthy is the very small intensity of this signal and that it only couples to the f 0 (980) isobar which is assumed to have a large strangeness content. The spin-exotic π 1 (1600) was observed albeit as a
International Nuclear Information System (INIS)
Tovey, S.N.; Hansen, J.D.; Paler, K.; Shah, T.P.; Borg, A.; Denegri, D.; Pons, Y.; Spiro, M.
1975-01-01
The reactions K - p→K - π + π - and K - p→ antikaon-neutral π - π 0 p at 14.3GeV/c has been studied using respectively 15992 and 3723 events. Partial wave analysis of the region 1.0 + but that the partial wave substrates have very different branching ratios into (rho) and K*π, the K*π component of the 1 + state being similar to the 1 + state of the 3π system produced in the reaction πp→(3π)p [fr
A partial wave analysis of world data for the reaction π-p → K0Λ from threshold to 2350 MeV/c
International Nuclear Information System (INIS)
Baker, R.D.; Blissett, J.A.; Bloodworth, I.J.
1977-06-01
All available world data for the reaction π - p → K 0 Λ up to 2350 MeV/c incident momentum have been analysed using both the Barrelet (Nuovo Cimento; 8A:331 (1972)) zero technique and a conventional energy-dependent fit. The results of the two methods are in good agreement. Resonances are required in the S 11 , P 11 , P 13 and D 13 partial waves. There is also an enhancement in the D 15 wave around 1900 MeV. No other resonances are required. (author)
International Nuclear Information System (INIS)
Workman, R. L.; Tiator, L.; Wunderlich, Y.; Doring, M.; Haberzettl, H.
2017-01-01
Here, we compare the methods of amplitude reconstruction, for a complete experiment and a truncated partial-wave analysis, applied to the photoproduction of pseudoscalar mesons. The approach is pedagogical, showing in detail how the amplitude reconstruction (observables measured at a single energy and angle) is related to a truncated partial-wave analysis (observables measured at a single energy and a number of angles).
International Nuclear Information System (INIS)
Dolbeau, Jean.
1976-01-01
The partial wave analysis of 91314 π + -p→Nππ events at nine CM energies between 1.38 and 1.74GeV was performed using the generalized isobar model and assuming the coherent production of Δ, rho and sigma in the final state. A coupled channel analysis (K-matrix formalism) led to the determination of the arbitrary phase at each energy and to smooth the partial wave amplitudes. The paramaters (mass, total and partial widths, signs of coupling constants) of sixteen resonances, among which two new ones, are determined by two different methods. Those results help in classifying the lower-mass excited states of the nucleon in the frame of unitary symmetries, as SU6 [fr
Microstrip natural wave spectrum mathematical model using partial inversion method
International Nuclear Information System (INIS)
Pogarsky, S.A.; Litvinenko, L.N.; Prosvirnin, S.L.
1995-01-01
It is generally agreed that both microstrip lines itself and different discontinuities based on microstrips are the most difficult problem for accurate electrodynamic analysis. Over the last years much has been published about principles and accurate (or full wave) methods of microstrip lines investigations. The growing interest for this problem may be explained by the microstrip application in the millimeter-wave range for purpose of realizing interconnects and a variety of passive components. At these higher operating rating frequencies accurate component modeling becomes more critical. A creation, examination and experimental verification of the accurate method for planar electrodynamical structures natural wave spectrum investigations are the objects of this manuscript. The moment method with partial inversion operator method using may be considered as a basical way for solving this problem. This method is outlook for accurate analysis of different planar discontinuities in microstrip: such as step discontinuities, microstrip turns, Y- and X-junctions and etc., substrate space steps dielectric constants and other anisotropy types
MAGNETOACOUSTIC WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA
Energy Technology Data Exchange (ETDEWEB)
Soler, Roberto; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Carbonell, Marc, E-mail: roberto.soler@uib.es, E-mail: joseluis.ballester@uib.es, E-mail: marc.carbonell@uib.es [Departament de Matemàtiques i Informàtica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)
2013-11-01
Compressible disturbances propagate in a plasma in the form of magnetoacoustic waves driven by both gas pressure and magnetic forces. In partially ionized plasmas the dynamics of ionized and neutral species are coupled due to ion-neutral collisions. As a consequence, magnetoacoustic waves propagating through a partially ionized medium are affected by ion-neutral coupling. The degree to which the behavior of the classic waves is modified depends on the physical properties of the various species and on the relative value of the wave frequency compared to the ion-neutral collision frequency. Here, we perform a comprehensive theoretical investigation of magnetoacoustic wave propagation in a partially ionized plasma using the two-fluid formalism. We consider an extensive range of values for the collision frequency, ionization ratio, and plasma β, so that the results are applicable to a wide variety of astrophysical plasmas. We determine the modification of the wave frequencies and study the frictional damping due to ion-neutral collisions. Approximate analytic expressions for the frequencies are given in the limit case of strongly coupled ions and neutrals, while numerically obtained dispersion diagrams are provided for arbitrary collision frequencies. In addition, we discuss the presence of cutoffs in the dispersion diagrams that constrain wave propagation for certain combinations of parameters. A specific application to propagation of compressible waves in the solar chromosphere is given.
MAGNETOACOUSTIC WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA
International Nuclear Information System (INIS)
Soler, Roberto; Ballester, Jose Luis; Carbonell, Marc
2013-01-01
Compressible disturbances propagate in a plasma in the form of magnetoacoustic waves driven by both gas pressure and magnetic forces. In partially ionized plasmas the dynamics of ionized and neutral species are coupled due to ion-neutral collisions. As a consequence, magnetoacoustic waves propagating through a partially ionized medium are affected by ion-neutral coupling. The degree to which the behavior of the classic waves is modified depends on the physical properties of the various species and on the relative value of the wave frequency compared to the ion-neutral collision frequency. Here, we perform a comprehensive theoretical investigation of magnetoacoustic wave propagation in a partially ionized plasma using the two-fluid formalism. We consider an extensive range of values for the collision frequency, ionization ratio, and plasma β, so that the results are applicable to a wide variety of astrophysical plasmas. We determine the modification of the wave frequencies and study the frictional damping due to ion-neutral collisions. Approximate analytic expressions for the frequencies are given in the limit case of strongly coupled ions and neutrals, while numerically obtained dispersion diagrams are provided for arbitrary collision frequencies. In addition, we discuss the presence of cutoffs in the dispersion diagrams that constrain wave propagation for certain combinations of parameters. A specific application to propagation of compressible waves in the solar chromosphere is given
Directory of Open Access Journals (Sweden)
Jong-In Lee
2014-01-01
Full Text Available This study presents wave height distribution in terms of stem wave evolution phenomena on partially perforated wall structures through three-dimensional laboratory experiments. The plain and partially perforated walls were tested to understand their effects on the stem wave evolution under the monochromatic and random wave cases with the various wave conditions, incident angle (from 10 to 40 degrees, and configurations of front and side walls. The partially perforated wall reduced the relative wave heights more effectively compared to the plain wall structure. Partially perforated walls with side walls showed a better performance in terms of wave height reduction compared to the structure without the side wall. Moreover, the relative wave heights along the wall were relatively small when the relative chamber width is large, within the range of the chamber width in this study. The wave spectra showed a frequency dependency of the wave energy dissipation. In most cases, the existence of side wall is a more important factor than the porosity of the front wall in terms of the wave height reduction even if the partially perforated wall was still effective compared to the plain wall.
Effective constants for wave propagation through partially saturated porous media
International Nuclear Information System (INIS)
Berryman, J.G.; Thigpen, L.
1985-01-01
The multipole scattering coefficients for elastic wave scattering from a spherical inhomogeneity in a fluid-saturated porous medium have been calculated. These coefficients may be used to obtain estimates of the effective macroscopic constants for long-wavelength propagation of elastic waves through partially saturated media. If the volume average of the single scattering from spherical bubbles of gas and liquid is required to vanish, the resulting equations determine the effective bulk modulus, density, and viscosity of the multiphase fluid filling the pores. The formula for the effective viscosity during compressional wave excitation is apparently new
ALFVÉN WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA
International Nuclear Information System (INIS)
Soler, R.; Ballester, J. L.; Terradas, J.; Carbonell, M.
2013-01-01
Alfvén waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfvén waves is affected by the interaction between ionized and neutral species. Here we study Alfvén waves in a partially ionized plasma from the theoretical point of view using the two-fluid description. We consider that the plasma is composed of an ion-electron fluid and a neutral fluid, which interact by means of particle collisions. To keep our investigation as general as possible, we take the neutral-ion collision frequency and the ionization degree as free parameters. First, we perform a normal mode analysis. We find the modification due to neutral-ion collisions of the wave frequencies and study the temporal and spatial attenuation of the waves. In addition, we discuss the presence of cutoff values of the wavelength that constrain the existence of oscillatory standing waves in weakly ionized plasmas. Later, we go beyond the normal mode approach and solve the initial-value problem in order to study the time-dependent evolution of the wave perturbations in the two fluids. An application to Alfvén waves in the low solar atmospheric plasma is performed and the implication of partial ionization for the energy flux is discussed.
DEFF Research Database (Denmark)
Frigaard, Peter; Andersen, Thomas Lykke
The present book describes the most important aspects of wave analysis techniques applied to physical model tests. Moreover, the book serves as technical documentation for the wave analysis software WaveLab 3, cf. Aalborg University (2012). In that respect it should be mentioned that supplementary...... to the present technical documentation exists also the online help document describing the WaveLab software in detail including all the inputs and output fields. In addition to the two main authors also Tue Hald, Jacob Helm-Petersen and Morten Møller Jakobsen have contributed to the note. Their input is highly...... acknowledged. The outline of the book is as follows: • Chapter 2 and 3 describes analysis of waves in time and frequency domain. • Chapter 4 and 5 describes the separation of incident and reflected waves for the two-dimensional case. • Chapter 6 describes the estimation of the directional spectra which also...
Alfven wave propagation in a partially ionized plasma
International Nuclear Information System (INIS)
Watts, Christopher; Hanna, Jeremy
2004-01-01
Results from a laboratory study of the dispersion relation of Alfven waves propagating through a partially ionized plasma are presented. The plasma is generated using a helicon source, creating a high density, current-free discharge, where the source can be adjusted to one of several modes with varying neutral fraction. Depending on the neutral fraction, the measured dispersion curve of shear Alfven waves can change significantly. Measurement results are compared with theoretical predictions of the effect of neutral particles on Alfven wave propagation. In fitting the theory, the neutral fraction is independently estimated using two simple particle transport models, one collisionless, the other collisional. The two models predict comparable neutral fractions, and agree well with the neutral fraction required for the Alfven dispersion theory
Nonlinear acoustic waves in partially ionized collisional plasmas
International Nuclear Information System (INIS)
Rao, N.N.; Kaup, D.J.; Shukla, P.K.
1991-01-01
Nonlinear propagation of acoustic-type waves in a partially ionized three-component collisional plasma consisting of electrons, ions and neutral particles is investigated. For bidirectional propagation, it is shown that the small- but finite-amplitude waves are governed by the Boussinesq equation, which for unidirectional propagation near the acoustic speed reduces to the usual Korteweg-de Vries equation. For large-amplitude waves, it is demonstrated that the relevant fluid equations are integrable in a stationary frame, and the parameter values for the existence of finite-amplitude solutions are explicitly obtained. In both cases, the different temperatures of the individual species, are taken into account. The relevance of the results to the earth's ionospheric plasma in the lower altitude ranges is pointed out. (author)
International Nuclear Information System (INIS)
Drevillon, B.; Borenstein, S.; Chaurand, B.; Gago, J.M.; Salmeron, R.A.; Borg, A.; Denegri, D.; Pons, Y.; Spiro, M.; Comber, C.; Paler, K.; Tovey, S.N.; Shah, T.P.
1975-01-01
A partial wave analysis of spin-parity of the (antikaon-neutral π + π - ) system in the mass range M(antikaon-neutral π + π - ) - and 1 + states is found, the unatural spin-parity accounting for more than 3/4 of the events at 3.95GeV/c and for more than half at 14.3GeV/c. Natural parity exchange is dominant at both energies. A fit of the cross sections of several states to Psub(lab)sup(-n) gives n between 1.5 and 2.0 [fr
A partial wave analysis of the (3π)0 system from the charge exchange reaction π+n→π+π-π0p at 4 GeV/c
International Nuclear Information System (INIS)
Emms, M.J.; Jones, G.T.; Kinson, J.B.; Stacey, B.J.; Votruba, M.F.; Woodworth, P.L.; Bell, I.G.; Dale, M.; Major, J.V.; Charlesworth, J.A.; Crennell, D.J.; Sekulin, R.L.
1975-10-01
From a partial wave analysis of the (3π) 0 state in the charge exchange reaction π + n→π + π - π 0 p, strong unnatural parity is observed as well as natural parity production. The observed natural parity states are identified with well-established resonances. The unnatural parity production is consistent with Reggeized Deck model predictions, with the exception of the I = 1 Jsup(p) = 1 + state. Here there is no evidence for A 1 production at approximately 1.1 GeV, but the data could support resonance production at higher masses. (author)
New results on the Roper resonance and the P-11 partial wave
Sarantsev, A. V.; Fuchs, M.; Kotulla, M.; Thoma, U.; Ahrens, J.; Annand, J. R. M.; Anisovich, A. V.; Anton, G.; Bantes, R.; Bartholomy, O.; Beck, R.; Beloglazov, Yu.; Castelijns, R.; Crede, V.; Ehmanns, A.; Ernst, J.; Fabry, I.; Flemming, H.; Foesel, A.; Funke, Chr.; Gothe, R.; Gridnev, A.; Gutz, E.; Hoeffgen, St.; Horn, I.; Hoessl, J.; Hornidge, D.; Janssen, S.; Junkersfeld, J.; Kalinowsky, H.; Klein, F.; Klempt, E.; Koch, H.; Konrad, M.; Kopf, B.; Krusche, B.; Langheinrich, J.; Loehner, H.; Lopatin, I.; Lotz, J.; McGeorge, J. C.; MacGregor, I. J. D.; Matthaey, H.; Menze, D.; Messchendorp, J. G.; Metag, V.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; van Pee, H.; Pfeiffer, M.; Radkov, A.; Rosner, G.; Rost, M.; Schmidt, C.; Schoch, B.; Suft, G.; Sumachev, V.; Szczepanek, T.; Walther, D.; Watts, D. P.; Weinheimer, Chr.
2008-01-01
Properties of the Roper resonance, the first scalar excitation of the nucleon, are determined. Pole positions and residues of the P-11 partial wave are studied in a combined analysis of pion- and photo-induced reactions. We find the Roper pole at {(1371 +/- 7) - i(92 +/- 10)} MeV and an elasticity
Two-nucleon Hulthen-type interactions for few higher partial waves
Indian Academy of Sciences (India)
The Hamiltonian hierarchy problems in SQM lead to the addition of appropriate centrifugal barriers and consequently, higher partial wave potentials are ... the partial waves l > 0 one needs to improve the parameters involved in calculations. The present paper addresses itself to compute higher partial wave scattering phase ...
MAGNETOHYDRODYNAMIC WAVES IN A PARTIALLY IONIZED FILAMENT THREAD
International Nuclear Information System (INIS)
Soler, R.; Oliver, R.; Ballester, J. L.
2009-01-01
Oscillations and propagating waves are commonly seen in high-resolution observations of filament threads, i.e., the fine-structures of solar filaments/prominences. Since the temperature of prominences is typically of the order of 10 4 K, the prominence plasma is only partially ionized. In this paper, we study the effect of neutrals on the wave propagation in a filament thread modeled as a partially ionized homogeneous magnetic flux tube embedded in an homogeneous and fully ionized coronal plasma. Ohmic and ambipolar magnetic diffusion are considered in the basic resistive magnetohydrodynamic (MHD) equations. We numerically compute the eigenfrequencies of kink, slow, and Alfven linear MHD modes and obtain analytical approximations in some cases. We find that the existence of propagating modes is constrained by the presence of critical values of the longitudinal wavenumber. In particular, the lower and upper frequency cutoffs of kink and Alfven waves owe their existence to magnetic diffusion parallel and perpendicular to magnetic field lines, respectively. The slow mode only has a lower frequency cutoff, which is caused by perpendicular magnetic diffusion and is significantly affected by the ionization degree. In addition, ion-neutral collision is the most efficient damping mechanism for short wavelengths, while ohmic diffusion dominates in the long-wavelength regime.
Plane waves and spherical means applied to partial differential equations
John, Fritz
2004-01-01
Elementary and self-contained, this heterogeneous collection of results on partial differential equations employs certain elementary identities for plane and spherical integrals of an arbitrary function, showing how a variety of results on fairly general differential equations follow from those identities. The first chapter deals with the decomposition of arbitrary functions into functions of the type of plane waves. Succeeding chapters introduce the first application of the Radon transformation and examine the solution of the initial value problem for homogeneous hyperbolic equations with con
Bulk elastic wave propagation in partially saturated porous solids
International Nuclear Information System (INIS)
Berryman, J.G.; Thigpen, L.; Chin, R.C.Y.
1988-01-01
The linear equations of motion that describe the behavior of small disturbances in a porous solid containing both liquid and gas are solved for bulk wave propagation. The equations have been simplified by neglecting effects due to changes in capillary pressure. With this simplifying assumption, the equations reduce to two coupled (vector) equations of the form found in Biot's equations (for full saturation) but with more complicated coefficients. As in fully saturated solids, two shear waves with the same speed but different polarizations exist as do two compressional waves with distinct speeds. Attenuation effects can be enhanced in the partially saturated solid, depending on the distribution of gas in the pore space. Two models of the liquid/gas spatial distribution are considered: a segregated-fluids model and a mixed-fluids model. The two models predict comparable attentuation when the gas saturation is low, but the segregated-fluids model predicts a more rapid roll-off of attenuation as the gas saturation increases
Plante, David T; Goldstein, Michael R; Cook, Jesse D; Smith, Richard; Riedner, Brady A; Rumble, Meredith E; Jelenchick, Lauren; Roth, Andrea; Tononi, Giulio; Benca, Ruth M; Peterson, Michael J
2016-02-01
Changes in slow waves during non-rapid eye movement (NREM) sleep in response to acute total sleep deprivation are well-established measures of sleep homeostasis. This investigation utilized high-density electroencephalography (hdEEG) to examine topographic changes in slow waves during repeated partial sleep deprivation. Twenty-four participants underwent a 6-day sleep restriction protocol. Spectral and period-amplitude analyses of sleep hdEEG data were used to examine changes in slow wave energy, count, amplitude, and slope relative to baseline. Changes in slow wave energy were dependent on the quantity of NREM sleep utilized for analysis, with widespread increases during sleep restriction and recovery when comparing data from the first portion of the sleep period, but restricted to recovery sleep if the entire sleep episode was considered. Period-amplitude analysis was less dependent on the quantity of NREM sleep utilized, and demonstrated topographic changes in the count, amplitude, and distribution of slow waves, with frontal increases in slow wave amplitude, numbers of high-amplitude waves, and amplitude/slopes of low amplitude waves resulting from partial sleep deprivation. Topographic changes in slow waves occur across the course of partial sleep restriction and recovery. These results demonstrate a homeostatic response to partial sleep loss in humans. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Mathematical Methods in Wave Propagation: Part 2--Non-Linear Wave Front Analysis
Jeffrey, Alan
1971-01-01
The paper presents applications and methods of analysis for non-linear hyperbolic partial differential equations. The paper is concluded by an account of wave front analysis as applied to the piston problem of gas dynamics. (JG)
Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction
Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.
2009-01-01
We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…
Corden, M J; Bellamy, E H; Corbett, I F; Dagan, S; Dowell, John D; Esterling, R J; Garvey, J; Gnat, Y; Green, M G; Harnew, N; Jobes, M; Kenyon, I R; Lipman, Norman H; Lister, J B; Lister, J R; Litchfield, P J; Mawson, J; McMahon, T; Robertson, A W; Stacey, B J; Strong, J A; Sumorok, K; Thomas, D H
1978-01-01
Data on the charge-exchange reaction pi /sup -/p to ( pi /sup +/ pi /sup -/ pi /sup 0/)n have been taken at beam momenta of 12 and 15 GeV /c, using the CERN Omega Multiparticle Spectrometer. A partial-wave analysis has been made of the (3 pi )/sup 0/ system. Both natural and unnatural spin-parity production was observed. The natural parity states can be identified with established resonances. In addition a natural spin-parity enhancement is observed at a mass of about 2 GeV/c /sup 2/ with J/sup P/=4/sup +/ preferred. This effect is called the A /sub 2/*(2030). The unnatural spin-parity production found is consistent with reggeized Deck model predictions. No unambiguous A/sub 1/ or A/sub 3/ production is observed. (15 refs).
Cerrada, M; Chaloupka, V; Foster, B; Heinen, P M; Hemingway, R J; Holmgren, S O; Kittel, E W; Losty, Michael J; Massaro, G G G; Metzger, W J; Vergeest, J S M; Wagner, F; Wells, J; Wolters, G F
1977-01-01
A partial-wave analysis of the (3 pi )/sup 0/ system produced peripherally in the reaction K/sup -/p to pi /sup +/ pi /sup -/ pi /sup 0/ Lambda at 4.2 GeV/c is presented. The observation of the weak Lambda decay allows a determination of all the transverse production amplitudes except for two phases. The production of known resonances having decay modes other than 3 pi is used to test the isobar model ansatz. Significant omega (783), phi (1020) and A/sub 2/(1310) production is observed. The spin parity of the omega *(1675) is established as 3/sup -/. No evidence for production of other resonances, such as axial vector-mesons, is found. (23 refs).
New results on the Roper resonance and the P{sub 11} partial wave
Energy Technology Data Exchange (ETDEWEB)
Sarantsev, A.V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Fuchs, M. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Kotulla, M. [Physikalisches Institut, Universitaet Basel (Switzerland); II. Physikalisches Institut, Universitaet Giessen (Germany); Thoma, U. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); II. Physikalisches Institut, Universitaet Giessen (Germany); Ahrens, J. [Institut fuer Kernphysik, Universitaet Mainz (Germany); Annand, J.R.M. [Department of Physics and Astronomy, University of Glasgow (United Kingdom); Anisovich, A.V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Anton, G. [Physikalisches Institut, Universitaet Erlangen (Germany); Bantes, R. [Physikalisches Institut, Universitaet Bonn (Germany); Bartholomy, O. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Beck, R. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Institut fuer Kernphysik, Universitaet Mainz (Germany); Beloglazov, Yu. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Castelijns, R. [KVI, Groningen (Netherlands); Crede, V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Department of Physics, Florida State University (United States); Ehmanns, A.; Ernst, J.; Fabry, I. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Flemming, H. [Physikalisches Institut, Universitaet Bochum (Germany); Foesel, A. [Physikalisches Institut, Universitaet Erlangen (Germany); Funke, Chr. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany)] (and others)
2008-01-17
Properties of the Roper resonance, the first scalar excitation of the nucleon, are determined. Pole positions and residues of the P{sub 11} partial wave are studied in a combined analysis of pion- and photo-induced reactions. We find the Roper pole at {l_brace}(1371{+-}7)-i(92{+-}10){r_brace} MeV and an elasticity of 0.61{+-}0.03. The largest decay coupling is found for the N{sigma} ({sigma}=({pi}{pi})-S-wave). The analysis is based on new data on {gamma}p{yields}p{pi}{sup 0}{pi}{sup 0} for photons in the energy range from the two-pion threshold to 820 MeV from TAPS at Mainz and from 0.4 to 1.3 GeV from Crystal Barrel at Bonn and includes further data from other experiments. The partial wave analysis excludes the possibility that the Roper resonance is split into two states with different partial decay widths.
Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek
2015-08-01
Plateau waves in intracranial pressure (ICP) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral oxygen (pbtO2) and a moving correlation coefficient between ICP and mean arterial blood pressure (ABP), called PRx, along with the cerebral oxygen reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. We analyzed 55 plateau waves in 20 patients after severe traumatic brain injury. We calculated ABP, ABP pulse amplitude (ampABP), ICP, CPP, pbtO2, heart rate (HR), ICP pulse amplitude (ampICP), PRx, and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same patient, independent because they are separated by long intervals. We found increases for ICP and ampICP according to our operational definitions for plateau waves. PRx increased significantly (p = 0.00026), CPP (p pressure remains stable in ICP plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may show a slight overshoot after normalization. We assume that this might be due to different latencies of the cerebral blood flow and oxygen level control mechanisms. Other factors may include baseline conditions, such as pre-plateau wave cerebrovascular reactivity or pbtO2 levels, which differ between studies.
Partial wave analyses of scattering below 2 GeV. Progress report, May 1, 1984-April 30, 1985
International Nuclear Information System (INIS)
Arndt, R.A.; Roper, L.D.
1985-08-01
Progress is reported in the partial wave analysis of nucleon-nucleon elastic scattering, pion-nucleon elastic scattering, and kaon plus-nucleon elastic scattering. Activities are also reported with respect to the Scattering Analysis Interactive Dial-in (SAID) facility
Numerical Analysis of Partial Differential Equations
Lui, S H
2011-01-01
A balanced guide to the essential techniques for solving elliptic partial differential equations Numerical Analysis of Partial Differential Equations provides a comprehensive, self-contained treatment of the quantitative methods used to solve elliptic partial differential equations (PDEs), with a focus on the efficiency as well as the error of the presented methods. The author utilizes coverage of theoretical PDEs, along with the nu merical solution of linear systems and various examples and exercises, to supply readers with an introduction to the essential concepts in the numerical analysis
Hemingway, Richard J; Harmsen D M; Kiesling, C; Petersen, J O; Plane, D E; Putzer, A; Wittex, W; Eades, J no 1; Harmsen D M no 1; Hemingway, R J no 1; Kiesling, C no 3; Petersen, J O no 1; Plane, D E no 3; Putzer, A no 2; Wittex, W no 3
1975-01-01
The angular distributions of the reactions K/sup -/p to K/sup -/p and K/sup -/p to K/sup 0/n have been measured at 23 incident K/sup -/ momenta between 1.136 and 1.798 GeV/c using the bubble chamber technique. These data, together with other published data on the same reactions, including K/sup -/p polarisations, KN total cross sections and measurements of Re f(0)/Im f(0), have been analysed in terms of partial-wave amplitudes. Resonance behaviour is confirmed for the P /sub 03/ partial wave at 1890 MeV. The resonance parameters of the F /sub 15/(1915), F/sub 17/(2030) and G/sub 07/(2100) have been redetermined. No evidence has been found for new resonances coupling significantly to KN in the energy region explored. (24 refs).
International Nuclear Information System (INIS)
Dolbeau, J.; Triantis, F.A.; Neveu, M.; Cadiet, F.
1975-01-01
A new partial wave analysis of the three reactions π - p→pπ - π 0 , π - p→nπ + π - , and π + p→pπ + π 0 is presented at nine c.m. energies between 1.36 and 1.76GeV, using about 91300 Nππ events. Within the framework of the generalized isobar model it is possible to describe the data with Δ, rho and sigma(ππ, i=0) production, as well as to reproduce the π - p→nπ 0 π 0 and π + p→nπ + π + cross sections. New prescriptions for the description of sigma and for the centrifugal barrier term are obtained. Furthermore, at the highest energy, there is evidence for N* production and for the presence of a ππ interaction, contributing about 5% to the cross sections of the reaction π - p→pπ - π 0 and π + p→pπ + π 0 . Finally, Argand plots are presented, showing the main inelastic couplings for ten resonances in this energy range [fr
International Nuclear Information System (INIS)
Nikolopoulos, L. A. A.; Kjeldsen, T. K.; Madsen, L. B.
2007-01-01
We present a method for spectral (bound and continuum) and partial-wave analysis of a three-dimensional time-dependent wave function, defined on a grid, without projecting onto the field-free eigenstates of the system. The method consists of propagating the time-dependent Schroedinger equation to obtain its autocorrelation function C(t)= after the end of the interaction, at time T, of the system with an external time-dependent field. The Fourier spectrum of this correlation function is directly related to the expansion coefficients of the wave function on the field-free bound and continuum energy eigenstates of the system. By expanding on a spherical harmonics basis we show how to calculate the contribution of the various partial waves to the total photoelectron energy spectrum
Parametric analysis of change in wave number of surface waves
Directory of Open Access Journals (Sweden)
Tadić Ljiljana
2015-01-01
Full Text Available The paper analyzes the dependence of the change wave number of materials soil constants, ie the frequency of the waves. The starting point in this analysis cosists of wave equation and dynamic stiffness matrix of soil.
Complex space source theory of partially coherent light wave.
Seshadri, S R
2010-07-01
The complex space source theory is used to derive a general integral expression for the vector potential that generates the extended full Gaussian wave in terms of the input value of the vector potential of the corresponding paraxial beam. The vector potential and the fields are assumed to fluctuate on a time scale that is large compared to the wave period. The Poynting vector in the propagation direction averaged over a wave period is expressed in terms of the cross-spectral density of the fluctuating vector potential across the input plane. The Schell model is assumed for the cross-spectral density. The radiation intensity distribution and the power radiated are determined. The effect of spatial coherence on the radiation intensity distribution and the radiated power are investigated for different values of the physical parameters. Illustrative numerical results are provided to bring out the effect of spatial coherence on the propagation characteristics of the fluctuating light wave.
Study on the electromagnetic waves propagation characteristics in partially ionized plasma slabs
Directory of Open Access Journals (Sweden)
Zhi-Bin Wang
2016-05-01
Full Text Available Propagation characteristics of electromagnetic (EM waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.
Extracting scattering phase shifts in higher partial waves from lattice QCD calculations
Energy Technology Data Exchange (ETDEWEB)
Luu, Thomas; Savage, Martin J.
2011-06-01
Lüscher’s method is routinely used to determine meson-meson, meson-baryon, and baryon-baryon s-wave scattering amplitudes below inelastic thresholds from lattice QCD calculations—presently at unphysical light-quark masses. In this work we review the formalism and develop the requisite expressions to extract phase shifts describing meson-meson scattering in partial waves with angular momentum l≤6 and l=9. The implications of the underlying cubic symmetry, and strategies for extracting the phase shifts from lattice QCD calculations, are presented, along with a discussion of the signal-to-noise problem that afflicts the higher partial waves.
Energy Technology Data Exchange (ETDEWEB)
Cutkosky, R E; Hicks, H R; Sandusky, J; Shih, C C [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA); Kelly, R L [California Univ., Livermore (USA). Lawrence Livermore Lab.; Miller, R C; Yokosawa, A [Argonne National Lab., Ill. (USA)
1976-01-05
K/sup +/p cross-section and polarization data have been analyzed in the momentum range 0.78-2.53 GeV/c. Single energy fits were made using an ACE parametrization which had no cutoff in J, was analytic and has Regge-asymptotic behaviour in the cut cos theta plane, and contained explicit contributions from P, rho, A2, ..lambda.., ..sigma.., and low-mass di-pion exchange. Direct channel analyticity constraints were imposed by a partial wave dispersion relation interpolation procedure, fitting expansions in regulated-norm optimal bases to each partial wave which entered as a search parameter in the single energy fits. Output from these two programs was then used for a simultaneous fit by a linearized least squares program which provided input for another iterative fitting cycle. No strong evidence for the existence of exotic resonances was found. The method of analytic smoothing, in comparison with 'shortest path' methods, is found to allow more significant threshold structure to appear in the amplitudes.
El Koussaifi, R; Tikan, A; Toffoli, A; Randoux, S; Suret, P; Onorato, M
2018-01-01
Rogue waves are extreme and rare fluctuations of the wave field that have been discussed in many physical systems. Their presence substantially influences the statistical properties of a partially coherent wave field, i.e., a wave field characterized by a finite band spectrum with random Fourier phases. Their understanding is fundamental for the design of ships and offshore platforms. In many meteorological conditions waves in the ocean are characterized by the so-called Joint North Sea Wave Project (JONSWAP) spectrum. Here we compare two unique experimental results: the first one has been performed in a 270 m wave tank and the other in optical fibers. In both cases, waves characterized by a JONSWAP spectrum and random Fourier phases have been launched at the input of the experimental device. The quantitative comparison, based on an appropriate scaling of the two experiments, shows a very good agreement between the statistics in hydrodynamics and optics. Spontaneous emergence of heavy tails in the probability density function of the wave amplitude is observed in both systems. The results demonstrate the universal features of rogue waves and provide a fundamental and explicit bridge between two important fields of research. Numerical simulations are also compared with experimental results.
El Koussaifi, R.; Tikan, A.; Toffoli, A.; Randoux, S.; Suret, P.; Onorato, M.
2018-01-01
Rogue waves are extreme and rare fluctuations of the wave field that have been discussed in many physical systems. Their presence substantially influences the statistical properties of a partially coherent wave field, i.e., a wave field characterized by a finite band spectrum with random Fourier phases. Their understanding is fundamental for the design of ships and offshore platforms. In many meteorological conditions waves in the ocean are characterized by the so-called Joint North Sea Wave Project (JONSWAP) spectrum. Here we compare two unique experimental results: the first one has been performed in a 270 m wave tank and the other in optical fibers. In both cases, waves characterized by a JONSWAP spectrum and random Fourier phases have been launched at the input of the experimental device. The quantitative comparison, based on an appropriate scaling of the two experiments, shows a very good agreement between the statistics in hydrodynamics and optics. Spontaneous emergence of heavy tails in the probability density function of the wave amplitude is observed in both systems. The results demonstrate the universal features of rogue waves and provide a fundamental and explicit bridge between two important fields of research. Numerical simulations are also compared with experimental results.
Exploiting partial knowledge for efficient model analysis
Macedo, Nuno; Cunha, Alcino; Pessoa, Eduardo José Dias
2017-01-01
The advancement of constraint solvers and model checkers has enabled the effective analysis of high-level formal specification languages. However, these typically handle a specification in an opaque manner, amalgamating all its constraints in a single monolithic verification task, which often proves to be a performance bottleneck. This paper addresses this issue by proposing a solving strategy that exploits user-provided partial knowledge, namely by assigning symbolic bounds to the problem’s ...
Role of peripheral partial waves in the angle scattering of nuclei
Energy Technology Data Exchange (ETDEWEB)
Aleixo, A N.F.; Canto, L F; Carrilho, P; Hussein, M S
1984-12-01
Properties of the elastic excitation function at 180 produced by deviations from the usual strong absorption S-matrix are studied. Deviations S-tilde are considered, with the shape of windows in l-space centered around a value l-tilde corresponding to a peripheral collision, and our analysis is concentrated on the interference of the partial waves neighbouring l-tilde. The conditions for constructive and destructive interference and the effect of odd-even staggering factors are investigated, in the presence and in the absence of Coulomb and nuclear refraction. The consequences of such interference on the anomalous behaviour of the 180 excitation functions for the elastic scattering of some n- nuclei are discussed, in connection with results of other works.
Robustness, Death of Spiral Wave in the Network of Neurons under Partial Ion Channel Block
International Nuclear Information System (INIS)
Jun, Ma; Long, Huang; Chun-Ni, Wang; Zhong-Sheng, Pu
2013-01-01
The development of spiral wave in a two-dimensional square array due to partial ion channel block (Potassium, Sodium) is investigated, the dynamics of the node is described by Hodgkin—Huxley neuron and these neurons are coupled with nearest neighbor connection. The parameter ratio x Na (and x K ), which defines the ratio of working ion channel number of sodium (potassium) to the total ion channel number of sodium (and potassium), is used to measure the shift conductance induced by channel block. The distribution of statistical variable R in the two-parameter phase space (parameter ratio vs. poisoning area) is extensively calculated to mark the parameter region for transition of spiral wave induced by partial ion channel block, the area with smaller factors of synchronization R is associated the parameter region that spiral wave keeps alive and robust to the channel poisoning. Spiral wave keeps alive when the poisoned area (potassium or sodium) and degree of intoxication are small, distinct transition (death, several spiral waves coexist or multi-arm spiral wave emergence) occurs under moderate ratio x Na (and x K ) when the size of blocked area exceeds certain thresholds. Breakup of spiral wave occurs and multi-arm of spiral waves are observed when the channel noise is considered. (interdisciplinary physics and related areas of science and technology)
A chiral quark model for meson electroproduction in the S11 partial wave
International Nuclear Information System (INIS)
Golli, B.; Sirca, S.
2011-01-01
We calculate the meson scattering and electroproduction amplitudes in the S11 partial wave in a coupled-channel approach that incorporates quasi-bound quark-model states. Using the quark wave functions and the quark-meson interaction from the Cloudy Bag Model, we obtain a good overall agreement with the available experimental results for the partial widths of the N(1535) and the N(1650) resonances as well as for the pion, eta and kaon electroproduction amplitudes. Our model is consistent with the N(1535) resonance being dominantly a genuine three-quark state rather than a quasi-bound state of mesons and baryons. (orig.)
Lamb, George L
1995-01-01
INTRODUCTORY APPLICATIONS OF PARTIAL DIFFERENTIAL EQUATIONS. With Emphasis on Wave Propagation and Diffusion. This is the ideal text for students and professionals who have some familiarity with partial differential equations, and who now wish to consolidate and expand their knowledge. Unlike most other texts on this topic, it interweaves prior knowledge of mathematics and physics, especially heat conduction and wave motion, into a presentation that demonstrates their interdependence. The result is a superb teaching text that reinforces the reader's understanding of both mathematics and physic
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.
Witten, Matthew
1983-01-01
Hyperbolic Partial Differential Equations, Volume 1: Population, Reactors, Tides and Waves: Theory and Applications covers three general areas of hyperbolic partial differential equation applications. These areas include problems related to the McKendrick/Von Foerster population equations, other hyperbolic form equations, and the numerical solution.This text is composed of 15 chapters and begins with surveys of age specific population interactions, populations models of diffusion, nonlinear age dependent population growth with harvesting, local and global stability for the nonlinear renewal eq
Ambiguous sets of partial wave amplitudes can intersect
International Nuclear Information System (INIS)
Kok, L.P.; Roo, M. de
1976-01-01
Continuation in energy as a method to resolve ambiguities in phase-shift analysis is discussed. It is shown that continuity in energy is not in all cases sufficient to resolve ambiguities, and examples are given of such cases for both spin 0 - spin 0 and spin 0 - spin 1/2 scattering. (author)
On the Extreme Wave Height Analysis
DEFF Research Database (Denmark)
Burcharth, H. F.; Liu, Zhou
1994-01-01
The determination of the design wave height is usually based on the statistical analysis of long-term extreme wave height measurements. After an introduction to the procedure of the extreme wave height analysis, the paper presents new development concerning various aspects of the extreme wave...... height analysis. Finally, the paper gives a practical example based on a data set of the hindcasted wave heights for a deep water location in the Mediterranean Sea....
Mathematical Modeling of Partial-Porous Circular Cylinders with Water Waves
Directory of Open Access Journals (Sweden)
Min-Su Park
2015-01-01
Full Text Available The interaction of water waves with partially porous-surfaced circular cylinders was investigated. A three-dimensional numerical modeling was developed based on the complete mathematical formulation of the eigenfunction expansion method in the potential flow. Darcy’s law was applied to describe the porous boundary. The partial-porous cylinder is composed of a porous-surfaced body near the free surface, and an impermeable-surfaced body with an end-capped rigid bottom below the porous region. The optimal ratio of the porous portion to the impermeable portion can be adopted to design an effective ocean structure with minimal hydrodynamic impact. To scrutinize the hydrodynamic interactions in N partial-porous circular cylinders, the computational fluid domain is divided into three regions: an exterior region, N inner porous body regions, and N regions beneath the body. Wave excitation forces and wave run-up on multibodied partial-porous cylinders are calculated and compared for various porous-portion ratios and wave conditions, all of which significantly influence the hydrodynamic property.
Partial wave expansions for arbitrary spin and the role of non-central forces
International Nuclear Information System (INIS)
Johnson, R.C.
1976-09-01
The partial wave expansion of the amplitudes used by Hooton and Johnson for the scattering of particles of arbitrary spin is derived. A discussion is given of the extent to which effects arising from transition matrix elements that are diagonal and nondiagonal in orbital angular momentum can be distinguished in observables
Partial wave expansions for arbitrary spin and the role of non-central forces
International Nuclear Information System (INIS)
Johnson, R.C.
1977-01-01
The partial wave expansion of the amplitudes used by Hooton and Johnson for the scattering of particles of arbitrary spin is derived. A discussion is given of the extent to which effects arising from transition matrix elements that are diagonal and non-diagonal in orbital angular momentum can be distinguished in observables. (Auth.)
Symmetrized partial-wave method for density-functional cluster calculations
International Nuclear Information System (INIS)
Averill, F.W.; Painter, G.S.
1994-01-01
The computational advantage and accuracy of the Harris method is linked to the simplicity and adequacy of the reference-density model. In an earlier paper, we investigated one way the Harris functional could be extended to systems outside the limits of weakly interacting atoms by making the charge density of the interacting atoms self-consistent within the constraints of overlapping spherical atomic densities. In the present study, a method is presented for augmenting the interacting atom charge densities with symmetrized partial-wave expansions on each atomic site. The added variational freedom of the partial waves leads to a scheme capable of giving exact results within a given exchange-correlation approximation while maintaining many of the desirable convergence and stability properties of the original Harris method. Incorporation of the symmetry of the cluster in the partial-wave construction further reduces the level of computational effort. This partial-wave cluster method is illustrated by its application to the dimer C 2 , the hypothetical atomic cluster Fe 6 Al 8 , and the benzene molecule
Analysis of flexural wave cloaks
Directory of Open Access Journals (Sweden)
Alfonso Climente
2016-12-01
Full Text Available This work presents a comprehensive study of the cloak for bending waves theoretically proposed by Farhat et al. [see Phys. Rev. Lett. 103, 024301 (2009] and later on experimentally realized by Stenger et al. [see Phys. Rev. Lett. 108, 014301 (2012]. This study uses a semi-analytical approach, the multilayer scattering method, which is based in the Kirchoff-Love wave equation for flexural waves in thin plates. Our approach was unable to reproduce the predicted behavior of the theoretically proposed cloak. This disagreement is here explained in terms of the simplified wave equation employed in the cloak design, which employed unusual boundary conditions for the cloaking shell. However, our approach reproduces fairly well the measured displacement maps for the fabricated cloak, indicating the validity of our approach. Also, the cloak quality has been here analyzed using the so called averaged visibility and the scattering cross section. The results obtained from both analysis let us to conclude that there is room for further improvements of this type of flexural wave cloak by using better design procedures.
Elastic meson-nucleon partial wave scattering analyses
International Nuclear Information System (INIS)
Arndt, R.A.
1986-01-01
Comprehensive analyses of π-n elastic scattering data below 1100 MeV(Tlab), and K+p scattering below 3 GeV/c(Plab) are discussed. Also discussed is a package of computer programs and data bases (scattering data, and solution files) through which users can ''explore'' these interactions in great detail; this package is known by the acronym SAID (for Scattering Analysis Interactive Dialin) and is accessible on VAX backup tapes, or by dialin to the VPI computers. The π-n, and k+p interactions will be described as seen through the SAID programs. A procedure will be described for generating an interpolating array from any of the solutions encoded in SAID; this array can then be used through a fortran callable subroutine (supplied as part of SAID) to give excellent amplitude reconstructions over a broad kinematic range
Theory of wave propagation in partially saturated double-porosity rocks: a triple-layer patchy model
Sun, Weitao; Ba, Jing; Carcione, José M.
2016-04-01
Wave-induced local fluid flow is known as a key mechanism to explain the intrinsic wave dissipation in fluid-saturated rocks. Understanding the relationship between the acoustic properties of rocks and fluid patch distributions is important to interpret the observed seismic wave phenomena. A triple-layer patchy (TLP) model is proposed to describe the P-wave dissipation process in a double-porosity media saturated with two immiscible fluids. The double-porosity rock consists of a solid matrix with unique host porosity and inclusions which contain the second type of pores. Two immiscible fluids are considered in concentric spherical patches, where the inner pocket and the outer sphere are saturated with different fluids. The kinetic and dissipation energy functions of local fluid flow (LFF) in the inner pocket are formulated through oscillations in spherical coordinates. The wave propagation equations of the TLP model are based on Biot's theory and the corresponding Lagrangian equations. The P-wave dispersion and attenuation caused by the Biot friction mechanism and the local fluid flow (related to the pore structure and the fluid distribution) are obtained by a plane-wave analysis from the Christoffel equations. Numerical examples and laboratory measurements indicate that P-wave dispersion and attenuation are significantly influenced by the spatial distributions of both, the solid heterogeneity and the fluid saturation distribution. The TLP model is in reasonably good agreement with White's and Johnson's models. However, differences in phase velocity suggest that the heterogeneities associated with double-porosity and dual-fluid distribution should be taken into account when describing the P-wave dispersion and attenuation in partially saturated rocks.
Wave propagations of curvilinear motors driven by partially laminated piezoelectric actuators
International Nuclear Information System (INIS)
Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Muensit, Supasarote; Tzou, Horn-Sen
2008-01-01
A piezoelectric arc stator is the key component delivering driving actions to an ultrasonic curvilinear motor. The arc stator drives the rotor along the arc structure to any specific angular position. Usually conventional stators in ultrasonic motors are fully bounded with piezoelectric patch actuators. To reduce production costs while maintaining similar driving characteristics, an arc stator partially bonded with piezoelectric actuators is proposed and its dynamic characteristics are analyzed in this study. The effect of actuator locations on the wave propagation is investigated. Both analytical and finite element results demonstrate similar dynamic responses. That is, the response of the wave propagation depends on specific locations of piezoelectric actuators. One of the two configurations investigated shows that the partially laminated piezoelectric actuator pattern can also generate rather steady traveling waves on the stator with consistent wave amplitude. This implies that the partially laminated actuator technique could be an alternative actuator pattern to the fully laminated actuators in the design of ultrasonic curvilinear motors or other finite-length ultrasonic motors
Re-ionization of a partially ionized plasma by an Alfven wave of moderate amplitude
International Nuclear Information System (INIS)
Brennan, M.H.; Sawley, M.L.
1980-01-01
The use of forced magnetic-acoustic oscillations to investigate the effect of a torsional hydromagnetic (Alfven) wave pulse of moderate amplitude on the properties of a partially ionized afterglow helium plasma is reported. Observations of the magnetic flux associated with the oscillations, measured at a number of frequencies are used to determine radial density profiles and to provide estimates of plasma temperature. The torsional wave is shown to cause significant re-ionization of the plasma with no corresponding increase in the plasma temperature. The presence of a number of energetic particles is evidenced by the production of a significant number of doubly charged helium ions. (author)
Shertzer, Janine; Temkin, A.
2003-01-01
As is well known, the full scattering amplitude can be expressed as an integral involving the complete scattering wave function. We have shown that the integral can be simplified and used in a practical way. Initial application to electron-hydrogen scattering without exchange was highly successful. The Schrodinger equation (SE), which can be reduced to a 2d partial differential equation (pde), was solved using the finite element method. We have now included exchange by solving the resultant SE, in the static exchange approximation, which is reducible to a pair of coupled pde's. The resultant scattering amplitudes, both singlet and triplet, calculated as a function of energy are in excellent agreement with converged partial wave results.
Calculation of the Full Scattering Amplitude without Partial Wave Decomposition II
Shertzer, J.; Temkin, A.
2003-01-01
As is well known, the full scattering amplitude can be expressed as an integral involving the complete scattering wave function. We have shown that the integral can be simplified and used in a practical way. Initial application to electron-hydrogen scattering without exchange was highly successful. The Schrodinger equation (SE) can be reduced to a 2d partial differential equation (pde), and was solved using the finite element method. We have now included exchange by solving the resultant SE, in the static exchange approximation. The resultant equation can be reduced to a pair of coupled pde's, to which the finite element method can still be applied. The resultant scattering amplitudes, both singlet and triplet, as a function of angle can be calculated for various energies. The results are in excellent agreement with converged partial wave results.
Properties of partial-wave amplitudes in conformal invariant field theories
Ferrara, Sergio; Grillo, A F
1975-01-01
Analyticity properties of partial-wave amplitudes of the conformal group O/sub D,2/ (D not necessarily integer) in configuration space are investigated. The presence of Euclidean singularities in the Wilson expansion in conformal invariant field theories is discussed, especially in connection with the program of formulating dynamical bootstrap conditions coming from the requirement of causality. The exceptional case of D-2 is discussed in detail. (18 refs).
Analysis of Measured and Simulated Supraglottal Acoustic Waves.
Fraile, Rubén; Evdokimova, Vera V; Evgrafova, Karina V; Godino-Llorente, Juan I; Skrelin, Pavel A
2016-09-01
To date, although much attention has been paid to the estimation and modeling of the voice source (ie, the glottal airflow volume velocity), the measurement and characterization of the supraglottal pressure wave have been much less studied. Some previous results have unveiled that the supraglottal pressure wave has some spectral resonances similar to those of the voice pressure wave. This makes the supraglottal wave partially intelligible. Although the explanation for such effect seems to be clearly related to the reflected pressure wave traveling upstream along the vocal tract, the influence that nonlinear source-filter interaction has on it is not as clear. This article provides an insight into this issue by comparing the acoustic analyses of measured and simulated supraglottal and voice waves. Simulations have been performed using a high-dimensional discrete vocal fold model. Results of such comparative analysis indicate that spectral resonances in the supraglottal wave are mainly caused by the regressive pressure wave that travels upstream along the vocal tract and not by source-tract interaction. On the contrary and according to simulation results, source-tract interaction has a role in the loss of intelligibility that happens in the supraglottal wave with respect to the voice wave. This loss of intelligibility mainly corresponds to spectral differences for frequencies above 1500 Hz. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.
Plateau Waves of Intracranial Pressure and Partial Pressure of Cerebral Oxygen.
Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek
2016-01-01
This study investigates 55 intracranial pressure (ICP) plateau waves recorded in 20 patients after severe traumatic brain injury (TBI) with a focus on a moving correlation coefficient between mean arterial pressure (ABP) and ICP, called PRx, which serves as a marker of cerebrovascular reactivity, and a moving correlation coefficient between ABP and cerebral partial pressure of oxygen (pbtO2), called ORx, which serves as a marker for cerebral oxygen reactivity. ICP and ICPamplitude increased significantly during the plateau waves, whereas CPP and pbtO2 decreased significantly. ABP, ABP amplitude, and heart rate remained unchanged. In 73 % of plateau waves PRx increased during the wave. ORx showed an increase during and a decrease after the plateau waves, which was not statistically significant. Our data show profound cerebral vasoparalysis on top of the wave and, to a lesser extent, impairment of cerebral oxygen reactivity. The different behavior of the indices may be due to the different latencies of the cerebral blood flow and oxygen level control mechanisms. While cerebrovascular reactivity is a rapidly reacting mechanism, cerebral oxygen reactivity is slower.
Surface wave energy absorption by a partially submerged bio-inspired canopy.
Nové-Josserand, C; Castro Hebrero, F; Petit, L-M; Megill, W M; Godoy-Diana, R; Thiria, B
2018-03-27
Aquatic plants are known to protect coastlines and riverbeds from erosion by damping waves and fluid flow. These flexible structures absorb the fluid-borne energy of an incoming fluid by deforming mechanically. In this paper we focus on the mechanisms involved in these fluid-elasticity interactions, as an efficient energy harvesting system, using an experimental canopy model in a wave tank. We study an array of partially-submerged flexible structures that are subjected to the action of a surface wave field, investigating in particular the role of spacing between the elements of the array on the ability of our system to absorb energy from the flow. The energy absorption potential of the canopy model is examined using global wave height measurements for the wave field and local measurements of the elastic energy based on the kinematics of each element of the canopy. We study different canopy arrays and show in particular that flexibility improves wave damping by around 40%, for which half is potentially harvestable.
Risk analysis of breakwater caisson under wave attack using load surface approximation
Kim, Dong Hyawn
2014-12-01
A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method (FORM) can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.
Directory of Open Access Journals (Sweden)
Gabriel Djedovic
2014-01-01
Full Text Available Extracorporeal shock wave therapy (ESWT enhances tissue vascularization and neoangiogenesis. Recent animal studies showed improved soft tissue regeneration using ESWT. In most cases, deep partial-thickness burns require skin grafting; the outcome is often unsatisfactory in function and aesthetic appearance. The aim of this study was to demonstrate the effect of ESWT on skin regeneration after deep partial-thickness burns. Under general anesthesia, two standardized deep partial-thickness burns were induced on the back of 30 male Wistar rats. Immediately after the burn, ESWT was given to rats of group 1 (N=15, but not to group 2 (N=15. On days 5, 10, and 15, five rats of each group were analyzed. Reepithelialization rate was defined, perfusion units were measured, and histological analysis was performed. Digital photography was used for visual documentation. A wound score system was used. ESWT enhanced the percentage of wound closure in group 1 as compared to group 2 (P<0.05. The reepithelialization rate was improved significantly on day 15 (P<0.05. The wound score showed a significant increase in the ESWT group. ESWT improves skin regeneration of deep partial-thickness burns in rats. It may be a suitable and cost effective treatment alternative in this type of burn wounds in the future.
New multidimensional partially integrable generalization of S-integrable N-wave equation
International Nuclear Information System (INIS)
Zenchuk, A. I.
2007-01-01
This paper develops a modification of the dressing method based on the inhomogeneous linear integral equation with integral operator having nonempty kernel. The method allows one to construct the systems of multidimensional partial differential equations having differential polynomial structure in any dimension n. The associated solution space is not full, although it is parametrized by certain number of arbitrary functions of (n-1) variables. We consider four-dimensional generalization of the classical (2+1)-dimensional S-integrable N-wave equation as an example
Reliability-based Calibration of Partial Safety Factors for Wave Energy Converters
DEFF Research Database (Denmark)
Ambühl, Simon; Kramer, Morten Mejlhede; Sørensen, John Dalsgaard
2015-01-01
of partial safety factors for design of welded details for wave energy converter applications is presented in this paper using probabilistic methods. The paper presents an example with focus on the Wavestar device. SN curves and Rainflow counting are used to model fatigue without considering inspections....... The influence of inspections is modelled using a fracture mechanics approach, which is calibrated by the SN curve approach. Furthermore, the paper assesses the influence of the inspection quality. The results show that with multiple inspections during the lifetime of the device and by applying a good inspection...
Highly directive Fabry-Perot leaky-wave nanoantennas based on optical partially reflective surfaces
Energy Technology Data Exchange (ETDEWEB)
Lorente-Crespo, M.; Mateo-Segura, C., E-mail: C.Mateo-Segura@hw.ac.uk [Institute of Sensors, Signals and Systems, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom)
2015-05-04
Nanoantennas enhance the conversion between highly localized electromagnetic fields and far-field radiation. Here, we investigate the response of a nano-patch partially reflective surface backed with a silver mirror to an optical source embedded at the centre of the structure. Using full wave simulations, we demonstrate a two orders of magnitude increased directivity compared to the isotropic radiator, 50% power confinement to a 13.8° width beam and a ±16 nm bandwidth. Our antenna does not rely on plasmonic phenomena thus reducing non-radiative losses and conserving source coherence.
Trend analysis of the wave storminess: the wave direction
Casas Prat, M.; Sierra, J. P.; Mösso, C.; Sánchez-Arcilla, A.
2009-09-01
directionality. It is based on 44 year hindcast model data (1958-2001) of the HIPOCAS project, enabling to work with a longer time series compared to the existing measured ones. 41 nodes of this database are used, containing 3 hourly simulated data of significant wave height and wave direction, among other parameters. For storm definition, the Peak Over Threshold (POT) method is used with some additional duration requirements in order to analyse statistically independent events (Mendoza & Jiménez, 2006). Including both wave height and storm duration, the wave storminess is characterised by the energy content (Mendoza & Jiménez, 2004), being in turn log-transformed because of its positive scale. Separately, the wave directionality itself is analysed in terms of different sectors and approaching their probability of occurrence by counting events and using Bayesian inference (Agresti, 2002). Therefore, the original data is transformed into compositional data and, before performing the trend analysis, the isometric logratio (ilr) transformation (Egozcue et al., 2003) is done. In general, the trend analysis methodology consists in two steps: 1) trend detection and 2) trend quantification. For 1) the Mann Kendall test is used in order to identify the nodes with significant trend. For these selected nodes, the trend quantification is done, comparing two methods: 1) a simple linear regression analysis complemented with the bootstrap technique and 2) a Bayesian analysis, assuming normally distributed data with linearly increasing mean. Preliminary results show no significant trend for both annual mean and maximum energy content except for some nodes located to the Northern Catalan coast. Regarding the wave direction (but not only considering stormy conditions) there is a tendency of North direction to decrease whereas South and Southeast direction seems to increase.
Data analysis techniques for gravitational wave observations
Indian Academy of Sciences (India)
Astrophysical sources of gravitational waves fall broadly into three categories: (i) transient and bursts, (ii) periodic or continuous wave and (iii) stochastic. Each type of source requires a different type of data analysis strategy. In this talk various data analysis strategies will be reviewed. Optimal filtering is used for extracting ...
Two-nucleon higher partial-wave scattering from lattice QCD
Directory of Open Access Journals (Sweden)
Evan Berkowitz
2017-02-01
Full Text Available We present a determination of nucleon-nucleon scattering phase shifts for ℓ≥0. The S, P, D and F phase shifts for both the spin-triplet and spin-singlet channels are computed with lattice Quantum ChromoDynamics. For ℓ>0, this is the first lattice QCD calculation using the Lüscher finite-volume formalism. This required the design and implementation of novel lattice methods involving displaced sources and momentum-space cubic sinks. To demonstrate the utility of our approach, the calculations were performed in the SU(3-flavor limit where the light quark masses have been tuned to the physical strange quark mass, corresponding to mπ=mK≈800 MeV. In this work, we have assumed that only the lowest partial waves contribute to each channel, ignoring the unphysical partial wave mixing that arises within the finite-volume formalism. This assumption is only valid for sufficiently low energies; we present evidence that it holds for our study using two different channels. Two spatial volumes of V≈(3.5 fm3 and V≈(4.6 fm3 were used. The finite-volume spectrum is extracted from the exponential falloff of the correlation functions. Said spectrum is mapped onto the infinite volume phase shifts using the generalization of the Lüscher formalism for two-nucleon systems.
Physics analysis of the gang partial rod drive event
International Nuclear Information System (INIS)
Boman, C.; Frost, R.L.
1992-08-01
During the routine positioning of partial-length control rods in Gang 3 on the afternoon of Monday, July 27, 1992, the partial-length rods continued to drive into the reactor even after the operator released the controlling toggle switch. In response to this occurrence, the Safety Analysis and Engineering Services Group (SAEG) requested that the Applied Physics Group (APG) analyze the gang partial rod drive event. Although similar accident scenarios were considered in analysis for Chapter 15 of the Safety Analysis Report (SAR), APG and SAEG conferred and agreed that this particular type of gang partial-length rod motion event was not included in the SAR. This report details this analysis
Nutritional and amino acid analysis of raw, partially fermented and ...
African Journals Online (AJOL)
African Journal of Food, Agriculture, Nutrition and Development ... The nutritional and amino acid analysis of raw and fermented seeds of Parkia ... between 4.27 and 8.33 % for the fully fermented and the partially fermented seeds, respectively.
Extreme Wave Analysis by Integrating Model and Wave Buoy Data
Directory of Open Access Journals (Sweden)
Fabio Dentale
2018-03-01
Full Text Available Estimating the extreme values of significant wave height (HS, generally described by the HS return period TR function HS(TR and by its confidence intervals, is a necessity in many branches of coastal science and engineering. The availability of indirect wave data generated by global and regional wind and wave model chains have brought radical changes to the estimation procedures of such probability distribution—weather and wave modeling systems are routinely run all over the world, and HS time series for each grid point are produced and published after assimilation (analysis of the ground truth. However, while the sources of such indirect data are numerous, and generally of good quality, many aspects of their procedures are hidden to the users, who cannot evaluate the reliability and the limits of the HS(TR deriving from such data. In order to provide a simple engineering tool to evaluate the probability of extreme sea-states as well as the quality of such estimates, we propose here a procedure based on integrating HS time series generated by model chains with those recorded by wave buoys in the same area.
International Nuclear Information System (INIS)
Nihan Onder; Alberto Teyssedou; Danila Roubtsov
2005-01-01
Full text of publication follows: In CANDU reactors the fuel channels are connected to inlet and outlet headers by feeder-pipes that consist of vertical and horizontal legs. In some feeders, orifices are installed for flow adjustment. During a postulated Loss of Coolant Accidents, the emergency cooling water injected into the inlet and outlet headers enters the fuel channels through the feeder pipes. Steam produced in the feeders and in the fuel channels may flow in the direction opposite to that of the water, thereby creating vertical to horizontal Counter-Current Flow (CCF). The rate at which the cooling water enters the fuel channel may be substantially limited by the flooding phenomena that entrains the water in the same direction as the steam flow. Steam flowing in the direction opposite to the cooling water can bring about the formation of slug flow. Long slugs of liquid moving at relatively high speed are transported back towards the headers by the steam. This phenomenon substantially reduces the amount of cooling water that can reach the reactor core. We conducted CCF experiments using a vertical-to-horizontal test section connected by 90 deg. elbows, with an orifice installed in the horizontal leg. Four different orifices were used to carry out the experiments. We have observed that soliton-type waves generated close to the elbow propagate in the horizontal leg towards the orifice, where a partial reflection takes place. Without an orifice, the soliton waves are reflected from the second elbow. The reflected waves move in the opposite direction to that of the incident wave. Since soliton-type waves are periodically generated, the incident and reflected waves interfere at some place in the horizontal leg. If the amplitude of the interference wave is high enough, the bridging of the tubes occur, which generates the slugs. During the experiments the water and air flow rates, pressures and void fraction distributions were measured. The slug propagation
The role of peripheral partial waves in the anomalous large angle scattering of n-α nuclei
International Nuclear Information System (INIS)
Aleixo, A.N.F.; Canto, L.F.; Carrilho, P.; Hussein, M.S.
1984-01-01
Properties of the elastic excitation function at 180 0 produced by deviations from the usual strong absorption S-matrix are studied. Deviations S approx. with the shape of windows in l-space, centered around a value l approx. corresponding to a peripheral collision are considered and the analysis is concentrated in the interference of the partial waves neighbouring l approx.. The conditions for constructive and destructive interference and the effect of odd-even staggering factors are investigated, in the presence and in the absence of Coulomb and nuclear refraction. The consequences of such interference on the anomalous behaviour of the 180 0 excitation function for the elastic scattering of some n-α nuclei are discussed, in connection with results of other works. (Author) [pt
Power absorption of high-frequency electromagnetic waves in a partially ionized magnetized plasma
International Nuclear Information System (INIS)
Guo Bin; Wang Xiaogang
2005-01-01
Power absorption of high-frequency electromagnetic waves in a uniformly magnetized plasma layer covering a highly conducting surface is studied under atmosphere conditions. It is assumed that the system consists of not only electrons and positive ions but negative ions as well. By a general formula derived in our previous work [B. Guo and X. G. Wang, Plasma Sci. Tech. 7, 2645 (2005)], the total power absorption in the plasma layer with multiple reflections between an air-plasma interface and the conducting surface is computed. The results show that although the existence of negative ions greatly reduces the total power absorption, the magnetization of the plasma can, however, partially enhance it. Parameter dependence of the effects is calculated and discussed
Fast solution of elliptic partial differential equations using linear combinations of plane waves.
Pérez-Jordá, José M
2016-02-01
Given an arbitrary elliptic partial differential equation (PDE), a procedure for obtaining its solution is proposed based on the method of Ritz: the solution is written as a linear combination of plane waves and the coefficients are obtained by variational minimization. The PDE to be solved is cast as a system of linear equations Ax=b, where the matrix A is not sparse, which prevents the straightforward application of standard iterative methods in order to solve it. This sparseness problem can be circumvented by means of a recursive bisection approach based on the fast Fourier transform, which makes it possible to implement fast versions of some stationary iterative methods (such as Gauss-Seidel) consuming O(NlogN) memory and executing an iteration in O(Nlog(2)N) time, N being the number of plane waves used. In a similar way, fast versions of Krylov subspace methods and multigrid methods can also be implemented. These procedures are tested on Poisson's equation expressed in adaptive coordinates. It is found that the best results are obtained with the GMRES method using a multigrid preconditioner with Gauss-Seidel relaxation steps.
Recommended practice for process sampling for partial pressure analysis
International Nuclear Information System (INIS)
Blessing, James E.; Ellefson, Robert E.; Raby, Bruce A.; Brucker, Gerardo A.; Waits, Robert K.
2007-01-01
This Recommended Practice describes and recommends various procedures and types of apparatus for obtaining representative samples of process gases from >10 -2 Pa (10 -4 Torr) for partial pressure analysis using a mass spectrometer. The document was prepared by a subcommittee of the Recommended Practices Committee of the American Vacuum Society. The subcommittee was comprised of vacuum users and manufacturers of mass spectrometer partial pressure analyzers who have practical experience in the sampling of process gas atmospheres
Statistical approach to partial equilibrium analysis
Wang, Yougui; Stanley, H. E.
2009-04-01
A statistical approach to market equilibrium and efficiency analysis is proposed in this paper. One factor that governs the exchange decisions of traders in a market, named willingness price, is highlighted and constitutes the whole theory. The supply and demand functions are formulated as the distributions of corresponding willing exchange over the willingness price. The laws of supply and demand can be derived directly from these distributions. The characteristics of excess demand function are analyzed and the necessary conditions for the existence and uniqueness of equilibrium point of the market are specified. The rationing rates of buyers and sellers are introduced to describe the ratio of realized exchange to willing exchange, and their dependence on the market price is studied in the cases of shortage and surplus. The realized market surplus, which is the criterion of market efficiency, can be written as a function of the distributions of willing exchange and the rationing rates. With this approach we can strictly prove that a market is efficient in the state of equilibrium.
Xiaoxing Zhang; Guozhi Zhang; Yalong Li; Jian Zhang; Rui Huang
2017-01-01
This study analyzed the transformer electromagnetic gap propagation characteristics. The influence of gap size is also analyzed, and the results experimentally verified. The obtained results indicated that the gap propagation characteristics of electromagnetic wave signals radiated by the partial discharge (PD) source in different directions are substantially different. The intensity of the electromagnetic wave in the gap reaches a maximum at a gap height of 1 cm; and inside the gap, the inte...
Bowen, LI; Zhibin, WANG; Qiuyue, NIE; Xiaogang, WANG; Fanrong, KONG; Zhenyu, WANG
2018-01-01
Intensive collisions between electrons and neutral particles in partially ionized plasmas generated in atmospheric/sub-atmospheric pressure environments can sufficiently affect the propagation characteristics of electromagnetic waves, particularly in the sub-wavelength regime. To investigate the collisional effect in such plasmas, we introduce a simplified plasma slab model with a thickness on the order of the wavelength of the incident electromagnetic wave. The scattering matrix method (SMM) is applied to solve the wave equation in the plasma slab with significant nonuniformity. Results show that the collisions between the electrons and the neutral particles, as well as the incident angle and the plasma thickness, can disturb the transmission and reduce reflection significantly.
Crack Detection with Lamb Wave Wavenumber Analysis
Tian, Zhenhua; Leckey, Cara; Rogge, Matt; Yu, Lingyu
2013-01-01
In this work, we present our study of Lamb wave crack detection using wavenumber analysis. The aim is to demonstrate the application of wavenumber analysis to 3D Lamb wave data to enable damage detection. The 3D wavefields (including vx, vy and vz components) in time-space domain contain a wealth of information regarding the propagating waves in a damaged plate. For crack detection, three wavenumber analysis techniques are used: (i) two dimensional Fourier transform (2D-FT) which can transform the time-space wavefield into frequency-wavenumber representation while losing the spatial information; (ii) short space 2D-FT which can obtain the frequency-wavenumber spectra at various spatial locations, resulting in a space-frequency-wavenumber representation; (iii) local wavenumber analysis which can provide the distribution of the effective wavenumbers at different locations. All of these concepts are demonstrated through a numerical simulation example of an aluminum plate with a crack. The 3D elastodynamic finite integration technique (EFIT) was used to obtain the 3D wavefields, of which the vz (out-of-plane) wave component is compared with the experimental measurement obtained from a scanning laser Doppler vibrometer (SLDV) for verification purposes. The experimental and simulated results are found to be in close agreement. The application of wavenumber analysis on 3D EFIT simulation data shows the effectiveness of the analysis for crack detection. Keywords: : Lamb wave, crack detection, wavenumber analysis, EFIT modeling
Generation and Analysis of Random Waves
DEFF Research Database (Denmark)
Liu, Zhou; Frigaard, Peter
applied to hydrology, wind mechanics, ice mechanics, etc., not to mention the fact that spectral analysis comes originally from optics and electronics. The book intents to be a textbook for senior and graduate students who have interest in coastal and offshore structures. The only pre......Sea waves are the most important phenomenon to be considered in the design of coastal and offshore structures. It should be stressed that, even though all contents in the book are related to sea waves, they have a broader application in practice. For example, the extreme theory has also been......-requirement for the book is the knowledge of linear wave theory....
DEFF Research Database (Denmark)
Morningstar, Colin; Bulava, John; Singha, Bijit
2017-01-01
An implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the L\\"uscher formalism and involving a Hermitian matrix known as the "box matrix" is described. The method includes higher partial waves and multiple decay channels. Two fitting procedures for estimating...
Directory of Open Access Journals (Sweden)
Colin Morningstar
2017-11-01
Full Text Available An implementation of estimating the two-to-two K-matrix from finite-volume energies based on the Lüscher formalism and involving a Hermitian matrix known as the “box matrix” is described. The method includes higher partial waves and multiple decay channels. Two fitting procedures for estimating the K-matrix parameters, which properly incorporate all statistical covariances, are discussed. Formulas and software for handling total spins up to S=2 and orbital angular momenta up to L=6 are obtained for total momenta in several directions. First tests involving ρ-meson decay to two pions include the L=3 and L=5 partial waves, and the contributions from these higher waves are found to be negligible in the elastic energy range.
Beutels, P; Edmunds, W J; Smith, R D
2008-11-01
We argue that traditional health economic analysis is ill-equipped to estimate the cost effectiveness and cost benefit of interventions that aim at controlling and/or preventing public health emergencies of international concern (such as pandemic influenza or severe acute respiratory syndrome). The implicit assumption of partial equilibrium within both the health sector itself and--if a wider perspective is adopted--the economy as a whole would be violated by such emergencies. We propose an alternative, with the specific aim of accounting for the behavioural changes and capacity problems that are expected to occur when such an outbreak strikes. Copyright (c) 2008 John Wiley & Sons, Ltd.
Nonlinear analysis of shear deformable beam-columns partially ...
African Journals Online (AJOL)
In this paper, a boundary element method is developed for the nonlinear analysis of shear deformable beam-columns of arbitrary doubly symmetric simply or multiply connected constant cross section, partially supported on tensionless Winkler foundation, undergoing moderate large deflections under general boundary ...
SYSTEMATIZATION AND ANALYSIS OF PARTIALLY AND FULLY HOMOMORPHIC CRYPTOSYSTEM
Directory of Open Access Journals (Sweden)
A. V. Epishkina
2016-12-01
Full Text Available In this article provides an overview of the known partially and fully homomorphic cryptosystem, such as: RSA, ElGamal, Paillier, Gentry and Halevi. Justified the homomorphic properties of the considered cryptosystems. The comparative analysis of the homomorphic encryption algorithms has been committed
Function spaces and partial differential equations volume 2 : contemporary analysis
Taheri, Ali
2015-01-01
This is a book written primarily for graduate students and early researchers in the fields of Analysis and Partial Differential Equations (PDEs). Coverage of the material is essentially self-contained, extensive and novel with great attention to details and rigour.
Towards a simple method of analysis for partially prestressed concrete
Bruggeling, A.S.G.
1983-01-01
This report examines the question whether, and to what extent, it is possible to leave the time-dependent effects out of account in the analysis of partially prestressed concrete, at least in so far as they relate to the redistribution of the stresses over the cross-section.
Quasifree electron mobility by the method of partial waves in liquid hydrocarbons and in fluid argon
International Nuclear Information System (INIS)
Vertes, A.
1983-01-01
Applicability of the fluctuation model was tested in the case of n-hexane, n-pentane, c-hexane, 2,2-dimethylbutane, 2,2,4,4-tetramethylpentane, iso-octane, and neopentane. In our model, the quasifree electrons have been assumed to be scattered by the conduction state energy fluctuations of the liquid. These fluctuations are, in turn, described as a consequence of density fluctuations. The scattering potential is supposed to be square well like and the cross section is calculated in terms of partial waves. Averages due to the density fluctuations and the electron kinetic energy distribution are determined numerically. Except for the first three materials, the calculation reproduced the experimental mobilities with reasonable values of the square well radius, which is the only fitting parameters. Further extension of the description concerning the density dependence of the low field mobility of fluid argon has been performed. The estimated fluctuation size as a function of density increases monotonically at the minimum of the mobility in accordance with the monotonic behavior of the isothermal compressibility in the same region
Salvat, Francesc; Jablonski, Aleksander; Powell, Cedric J.
2005-01-01
-103) obtained from multiconfiguration Dirac-Fock self-consistent calculations. For comparison purposes, three simple analytical approximations to the electron density of neutral atoms (corresponding to the Thomas-Fermi, the Thomas-Fermi-Dirac and the Dirac-Hartree-Fock-Slater models) are also included. For calculations of elastic scattering by ions, the electron density should be provided by the user. The exchange potential for electron scattering can be selected among three different analytical approximations (Thomas-Fermi, Furness-McCarthy, Riley-Truhlar). The offered options for the correlation-polarization potential are based on the empirical Buckingham potential. The imaginary absorption potential is calculated from the local-density approximation proposed by Salvat [Phys. Rev. A 68 (2003) 012708]. Program summaryTitle of program:ELSEPA Catalogue identifier: ADUS Program summary URL:http://cpc.cs.qub.ac.uk/cpc/summaries/ADUS Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland License provisions: none Computer for which the program is designed and others in which it is operable: Any computer with a FORTRAN 77 compiler Operating systems under which the program has been tested: Windows XP, Windows 2000, Debian GNU/Linux 3.0r0 (sarge) Compilers:Compaq Visual Fortran v6.5 (Windows); GNU FORTRAN, g77 (Windows and Linux) Programming language used: FORTRAN 77 No. of bits in a word: 32 Memory required to execute with typical data: 0.6 Mb No. of lines in distributed program, including test data, etc.:135 489 No. of bytes in distributed program, including test data, etc.: 1 280 006 Distribution format: tar.gz Keywords: Dirac partial-wave analysis, electron elastic scattering, positron elastic scattering, differential cross sections, momentum transfer cross sections, transport cross sections, scattering amplitudes, spin polarization, scattering by complex potentials, high-energy atomic screening functions Nature of the physical problem: The code
Testing, Analysis and Control of Wave Dragon, Wave Energy Converter
DEFF Research Database (Denmark)
Tedd, James
of the incident waves upon a wave device allows the possibility of accurately tuning the power-take off mechanism (the hydro-turbines for the Wave Dragon) to capture more energy. A digital filter method for performing this prediction in real-time with minimal computational effort is presented. Construction...... of digital filters is well known within signal processing, but their use for this application in Wave Energy is new. The filter must be designed carefully as the frequency components of waves travel at different speeds. Research presented in this thesis has advanced the development of the Wave Dragon device...
Ballester, J. L.; Carbonell, M.; Soler, R.; Terradas, J.
2018-01-01
Context. During heating or cooling processes in prominences, the plasma microscopic parameters are modified due to the change of temperature and ionization degree. Furthermore, if waves are excited on this non-stationary plasma, the changing physical conditions of the plasma also affect wave dynamics. Aims: Our aim is to study how temporal variation of temperature and microscopic plasma parameters modify the behaviour of magnetohydrodynamic (MHD) waves excited in a prominence-like hydrogen plasma. Methods: Assuming optically thin radiation, a constant external heating, the full expression of specific internal energy, and a suitable energy equation, we have derived the profiles for the temporal variation of the background temperature. We have computed the variation of the ionization degree using a Saha equation, and have linearized the single-fluid MHD equations to study the temporal behaviour of MHD waves. Results: For all the MHD waves considered, the period and damping time become time dependent. In the case of Alfvén waves, the cut-off wavenumbers also become time dependent and the attenuation rate is completely different in a cooling or heating process. In the case of slow waves, while it is difficult to distinguish the slow wave properties in a cooling partially ionized plasma from those in an almost fully ionized plasma, the period and damping time of these waves in both plasmas are completely different when the plasma is heated. The temporal behaviour of the Alfvén and fast wave is very similar in the cooling case, but in the heating case, an important difference appears that is related with the time damping. Conclusions: Our results point out important differences in the behaviour of MHD waves when the plasma is heated or cooled, and show that a correct interpretation of the observed prominence oscillations is very important in order to put accurate constraints on the physical situation of the prominence plasma under study, that is, to perform prominence
Theoretical study of ghost imaging with cold atomic waves under the condition of partial coherence
International Nuclear Information System (INIS)
Chen, Jun; Liu, Yun-Xian
2014-01-01
A matter wave ghost imaging mechanism is proposed and demonstrated theoretically. This mechanism is based on the Talbot-Lau effect. Periodic gratings of matter wave density, which appear as a result of interference of atoms diffracted by pulses of an optical standing wave, are utilized to produce the reference wave and the signal wave simultaneously for the ghost imaging. An advantage of this mechanism is that during the imaging process, the beam-splitter is not needed, which highly simplifies the experimental setup and makes the ghost imaging possible in the field of matter wave
Statistical analysis on extreme wave height
Digital Repository Service at National Institute of Oceanography (India)
Teena, N.V.; SanilKumar, V.; Sudheesh, K.; Sajeev, R.
-294. • WAFO (2000) – A MATLAB toolbox for analysis of random waves and loads, Lund University, Sweden, homepage http://www.maths.lth.se/matstat/wafo/,2000. 15 Table 1: Statistical results of data and fitted distribution for cumulative distribution...
Manual for wave generation and analysis
DEFF Research Database (Denmark)
Jakobsen, Morten Møller
This Manual is for the included wave generation and analysis software and graphical user interface. The package is made for Matlab and is meant for educational purposes. The code is free to use under the GNU Public License (GPL). It is still in development and should be considered as such. If you...
Statistical Analysis of Wave Climate Data Using Mixed Distributions and Extreme Wave Prediction
Directory of Open Access Journals (Sweden)
Wei Li
2016-05-01
Full Text Available The investigation of various aspects of the wave climate at a wave energy test site is essential for the development of reliable and efficient wave energy conversion technology. This paper presents studies of the wave climate based on nine years of wave observations from the 2005–2013 period measured with a wave measurement buoy at the Lysekil wave energy test site located off the west coast of Sweden. A detailed analysis of the wave statistics is investigated to reveal the characteristics of the wave climate at this specific test site. The long-term extreme waves are estimated from applying the Peak over Threshold (POT method on the measured wave data. The significant wave height and the maximum wave height at the test site for different return periods are also compared. In this study, a new approach using a mixed-distribution model is proposed to describe the long-term behavior of the significant wave height and it shows an impressive goodness of fit to wave data from the test site. The mixed-distribution model is also applied to measured wave data from four other sites and it provides an illustration of the general applicability of the proposed model. The methodologies used in this paper can be applied to general wave climate analysis of wave energy test sites to estimate extreme waves for the survivability assessment of wave energy converters and characterize the long wave climate to forecast the wave energy resource of the test sites and the energy production of the wave energy converters.
Analysis of critically refracted longitudinal waves
Energy Technology Data Exchange (ETDEWEB)
Pei, Ning, E-mail: npei@iastate.edu; Bond, Leonard J., E-mail: npei@iastate.edu [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011 (United States)
2015-03-31
Fabrication processes, such as, welding, forging, and rolling can induce residual stresses in metals that will impact product performance and phenomena such as cracking and corrosion. To better manage residual stress tools are needed to map their distribution. The critically refracted ultrasonic longitudinal (LCR) wave is one such approach that has been used for residual stress characterization. It has been shown to be sensitive to stress and less sensitive to the effects of the texture of the material. Although the LCR wave is increasingly widely applied, the factors that influence the formation of the LCR beam are seldom discussed. This paper reports a numerical model used to investigate the transducers' parameters that can contribute to the directionality of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams. This method provides a design tool that can be used to study and optimize multiple parameter experiments and it can identify which parameter or parameters are of most significance. The simulation of the sound field in a 2-D 'water-steel' model is obtained using a Spatial Fourier Analysis method. The effects of incident angle, standoff, the aperture and the center frequency of the transducer were studied. Results show that the aperture of the transducer, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.
Directory of Open Access Journals (Sweden)
Hasibun Naher
2012-01-01
Full Text Available We construct new analytical solutions of the (3+1-dimensional modified KdV-Zakharov-Kuznetsev equation by the Exp-function method. Plentiful exact traveling wave solutions with arbitrary parameters are effectively obtained by the method. The obtained results show that the Exp-function method is effective and straightforward mathematical tool for searching analytical solutions with arbitrary parameters of higher-dimensional nonlinear partial differential equation.
The analysis of interfacial waves
International Nuclear Information System (INIS)
Galimov, Azat Yu.; Drew, Donald A.; Lahey, Richard T.; Moraga, Francisco J.
2005-01-01
We present analytical results for stable stratified wavy two-phase flow and functional forms for the various interfacial force densities in a two-fluid model. In particular, we have derived analytically the components of the non-drag interfacial force density [Drew, D.A., Passman, S.L., 1998. Theory of Multicomponent Fluids. Springer-Verlag, New York; Nigmatulin, T.R., Drew, D.A., Lahey, R.T., Jr., 2000. An analysis of wavy annular flow. In: International Conference on Multiphase Systems, ICMS'2000, Ufa, Russia, June 15-17], Reynolds stress tensor, and the term, (p-bar cl i -p-bar cl )-bar α cl , where p-bar cl i is interfacial average pressure, p-bar cl the average pressure, and α cl is the volume fraction of the continuous liquid phase. These functional forms should be useful for assessing two-fluid closure relations and Computational Multiphase Fluid Dynamics (CMFD) numerical models for stratified wavy flows. Moreover, it appears that this approach can be generalized to other flow regimes (e.g., annular flows)
Coupled channel analysis of s-wave ππ and K anti-K photoproduction
International Nuclear Information System (INIS)
Chueng-Ryong Ji; Szczepaniak, A.; Kaminski, R.; Lesniak, L.; Williams, R.
1997-10-01
We present a coupled channel partial wave analysis of non-diffractive S-wave π + π - and K + K - photoproduction focusing on the K anti-K threshold. Final state interactions are included. We calculate total cross sections, angular and effective mass distributions in both ππ and K anti-K channels. Our results indicate that these processes are experimentally measurable and valuable information on the f 0 (980) resonance structure can be obtained. (author)
Effect of H-wave polarization on laser radar detection of partially convex targets in random media.
El-Ocla, Hosam
2010-07-01
A study on the performance of laser radar cross section (LRCS) of conducting targets with large sizes is investigated numerically in free space and random media. The LRCS is calculated using a boundary value method with beam wave incidence and H-wave polarization. Considered are those elements that contribute to the LRCS problem including random medium strength, target configuration, and beam width. The effect of the creeping waves, stimulated by H-polarization, on the LRCS behavior is manifested. Targets taking large sizes of up to five wavelengths are sufficiently larger than the beam width and are sufficient for considering fairly complex targets. Scatterers are assumed to have analytical partially convex contours with inflection points.
Directory of Open Access Journals (Sweden)
Xiaoxing Zhang
2017-10-01
Full Text Available This study analyzed the transformer electromagnetic gap propagation characteristics. The influence of gap size is also analyzed, and the results experimentally verified. The obtained results indicated that the gap propagation characteristics of electromagnetic wave signals radiated by the partial discharge (PD source in different directions are substantially different. The intensity of the electromagnetic wave in the gap reaches a maximum at a gap height of 1 cm; and inside the gap, the intensity of the electromagnetic wave depicted an increasing trend at the tail area of the gap. Finally, from the obtained results, some suggestions on where to install sensors in practical systems for ultra high frequency (UHF PD signal detection in the transformer gap are provided. The obtained results confirmed the feasibility of using this approach. These results can be seen as a benchmark and a challenge for further research in this field.
Energy Technology Data Exchange (ETDEWEB)
Martínez-Gómez, David; Soler, Roberto; Terradas, Jaume, E-mail: david.martinez@uib.es [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain)
2017-03-01
The presence of neutral species in a plasma has been shown to greatly affect the properties of magnetohydrodynamic waves. For instance, the interaction between ions and neutrals through momentum transfer collisions causes the damping of Alfvén waves and alters their oscillation frequency and phase speed. When the collision frequencies are larger than the frequency of the waves, single-fluid magnetohydrodynamic approximations can accurately describe the effects of partial ionization, since there is a strong coupling between the various species. However, at higher frequencies, the single-fluid models are not applicable and more complex approaches are required. Here, we use a five-fluid model with three ionized and two neutral components, which takes into consideration Hall’s current and Ohm’s diffusion in addition to the friction due to collisions between different species. We apply our model to plasmas composed of hydrogen and helium, and allow the ionization degree to be arbitrary. By analyzing the corresponding dispersion relation and numerical simulations, we study the properties of small-amplitude perturbations. We discuss the effect of momentum transfer collisions on the ion-cyclotron resonances and compare the importance of magnetic resistivity, and ion–neutral and ion–ion collisions on the wave damping at various frequency ranges. Applications to partially ionized plasmas of the solar atmosphere are performed.
Shebloski, Barbara; Conger, Katherine J; Widaman, Keith F
2005-12-01
This study examined reciprocal links between parental differential treatment, siblings' perception of partiality, and self-worth with 3 waves of data from 384 adolescent sibling dyads. Results suggest that birth-order status was significantly associated with self-worth and perception of maternal and paternal differential treatment. There was a consistent across-time effect of self-worth on perception of parental partiality for later born siblings, but not earlier born siblings, and a consistent effect of differential treatment on perception of partiality for earlier born but not later born siblings. The results contribute new insight into the associations between perception of differential parenting and adolescents' adjustment and the role of birth order. Copyright 2006 APA, all rights reserved).
Meta-analysis of adjunctive levetiracetam in refractory partial sei
Directory of Open Access Journals (Sweden)
ZHANG Ying
2012-10-01
Full Text Available Objective To evaluate the effects and tolerability of adjunctive levetiracetam (LEV in refractory partial seizures. Methods Relevant research articles about randomized controlled trials of adjunctive LEV in refractory partial seizures from January 1998 to December 2010 were retrieved from Cochrane Library, MEDLINE, EMbase, Social Sciences Citation Index (SSCI, VIP, Chinese National Knowledge Infrastructure (CNKI database, China Biology Medicine (CBM. Two reviewers independently evaluated the quality of the included articles and abstracted the data. A Meta-analysis was conducted by using RevMan 5.0 software. Results According to the enrollment criteria, eleven prospective, randomized controlled clinical trials with a total of 1192 in LEV group and 789 in placebo group were finally selected. The reduction in three endpoints (a 50% or greater reduction of partial seizure frequency per week, a 75% or greater reduction of partial seizure frequency per week and seizure free was significant in LEV group than placebo group. There was no significance between LEV group and placebo group in the withdrawl rate (1000 mg/d: OR = 1.180, 95%CI: 0.690-2.010, P = 0.540; 2000 mg/d: OR = 1.530, 95%CI: 0.770-3.030, P = 0.230; 3000 mg/d: OR = 1.000, 95% CI: 0.620-1.600, P = 1.000. The following adverse events were associated with LEV: somnolence (OR = 1.720, 95%CI: 1.280-2.310, P = 0.000, dizziness (OR = 1.490, 95%CI: 1.000-2.220, P = 0.050, asthenia (OR = 1.670, 95%CI: 1.140-2.240, P = 0.008, nasopharyngitis (OR = 1.120, 95% CI: 0.710-1.760, P = 0.630, psychiatric and behavioral abnormalities (OR = 2.120, 95% CI: 1.370-3.280, P = 0.000. Conclusion LEV is effective and well tolerated when added to existing therapy in patients with refractory partial seizures compared with control drugs. Further studies are needed to identify the effects of monotherapy of LEV in partial seizures.
Sorghum cobalt analysis on not determined wave length with atomic ...
African Journals Online (AJOL)
This study was to know the better wave length on measuring cobalt content in forage sorghum hybrid (Sorghum bicolor) with an atomic absorption spectrophotometer. The analysis was on background correction mode with three wave lengths; 240.8, 240.7 (determined wave length or recommended wave length) and 240.6 ...
Seismic Response Analysis of Continuous Multispan Bridges with Partial Isolation
Directory of Open Access Journals (Sweden)
E. Tubaldi
2015-01-01
Full Text Available Partially isolated bridges are a particular class of bridges in which isolation bearings are placed only between the piers top and the deck whereas seismic stoppers restrain the transverse motion of the deck at the abutments. This paper proposes an analytical formulation for the seismic analysis of these bridges, modelled as beams with intermediate viscoelastic restraints whose properties describe the pier-isolator behaviour. Different techniques are developed for solving the seismic problem. The first technique employs the complex mode superposition method and provides an exact benchmark solution to the problem at hand. The two other simplified techniques are based on an approximation of the displacement field and are useful for preliminary assessment and design purposes. A realistic bridge is considered as case study and its seismic response under a set of ground motion records is analyzed. First, the complex mode superposition method is applied to study the characteristic features of the dynamic and seismic response of the system. A parametric analysis is carried out to evaluate the influence of support stiffness and damping on the seismic performance. Then, a comparison is made between the exact solution and the approximate solutions in order to evaluate the accuracy and suitability of the simplified analysis techniques for evaluating the seismic response of partially isolated bridges.
Energy Technology Data Exchange (ETDEWEB)
Wunderlich, Y.; Afzal, F.; Thiel, A.; Beck, R. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany)
2017-05-15
This work presents a simple method to determine the significant partial wave contributions to experimentally determined observables in pseudoscalar meson photoproduction. First, fits to angular distributions are presented and the maximum orbital angular momentum L{sub max} needed to achieve a good fit is determined. Then, recent polarization measurements for γp → π{sup 0}p from ELSA, GRAAL, JLab and MAMI are investigated according to the proposed method. This method allows us to project high-spin partial wave contributions to any observable as long as the measurement has the necessary statistical accuracy. We show, that high precision and large angular coverage in the polarization data are needed in order to be sensitive to high-spin resonance states and thereby also for the finding of small resonance contributions. This task can be achieved via interference of these resonances with the well-known states. For the channel γp → π{sup 0}p, those are the N(1680)(5)/(2){sup +} and Δ(1950)(7)/(2){sup +}, contributing to the F-waves. (orig.)
Eikonal Approximation in AdS/CFT: Conformal Partial Waves and Finite N Four-Point Functions
Cornalba, L; Penedones, J; Schiappa, R; Cornalba, Lorenzo; Costa, Miguel S.; Penedones, Joao; Schiappa, Ricardo
2007-01-01
We introduce the impact-parameter representation for conformal field theory correlators of the form A ~ . This representation is appropriate in the eikonal kinematical regime, and approximates the conformal partial-wave decomposition in the limit of large spin and dimension of the exchanged primary. Using recent results on the two-point function _{shock} in the presence of a shock wave in Anti-de Sitter, and its relation to the discontinuity of the four-point amplitude A across a kinematical branch-cut, we find the high spin and dimension conformal partial- wave decomposition of all tree-level Anti-de Sitter Witten diagrams. We show that, as in flat space, the eikonal kinematical regime is dominated by the T-channel exchange of the massless particle with highest spin (graviton dominance). We also compute the anomalous dimensions of the high-spin O_1 O_2 composites. Finally, we conjecture a formula re-summing crossed-ladder Witten diagrams to all orders in the gravitational coupling.
Eikonal approximation in AdS/CFT: Conformal partial waves and finite N four-point functions
International Nuclear Information System (INIS)
Cornalba, Lorenzo; Costa, Miguel S.; Penedones, Joao; Schiappa, Ricardo
2007-01-01
We introduce the impact parameter representation for conformal field theory correlators of the form A∼ 1 O 2 O 1 O 2 >. This representation is appropriate in the eikonal kinematical regime, and approximates the conformal partial wave decomposition in the limit of large spin and dimension of the exchanged primary. Using recent results on the two-point function 1 O 1 > shock in the presence of a shock wave in anti-de Sitter, and its relation to the discontinuity of the four-point amplitude A across a kinematical branch cut, we find the high spin and dimension conformal partial wave decomposition of all tree-level anti-de Sitter Witten diagrams. We show that, as in flat space, the eikonal kinematical regime is dominated by the T-channel exchange of the massless particle with highest spin (graviton dominance). We also compute the anomalous dimensions of the high spin O 1 O 2 composites. Finally, we conjecture a formula re-summing crossed-ladder Witten diagrams to all orders in the gravitational coupling
Partial digitization method of wave processes in rail lines on the discrete basis
International Nuclear Information System (INIS)
Tyurekhodzhaev, A.N.; Ibraev, A.G.
2006-01-01
Analytical solution of the problem about longitudinal vibration of the rail which lies on the ties taking into account contact dry friction between wheel and rail is provided by the method of partial digitization and Laplace dual integral transformation. (author)
Energy Technology Data Exchange (ETDEWEB)
Ditsche, Christoph; Hoferichter, Martin; Kubis, Bastian [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn (Germany); Bethe Center for Theoretical Physics, Bonn (Germany); Meissner, Ulf G. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn (Germany); Institut fuer Kernphysik (Theorie), Institute for Advanced Simulations, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Bethe Center for Theoretical Physics, Bonn (Germany)
2011-07-01
Starting from (subtracted) hyperbolic dispersion relations for {pi}N scattering, which are based on the general principles of Lorentz invariance, unitarity, crossing and analyticity as well as isospin symmetry, we propose a closed system of (subtracted) hyperbolic partial wave dispersion relations for the partial waves f{sup I}{sub l{+-}}({radical}(s)) of the s-channel reaction {pi}N{yields}{pi}N and the partial waves f{sup J}{sub {+-}}(t) of the t-channel reaction {pi}{pi}{yields} anti NN in the spirit of Roy and Steiner. A key step to the ultimate goal of solving this Roy-Steiner system is to first solve the corresponding (subtracted) Muskhelishvili-Omnes problem with inelasticities and a finite matching point for the lowest t-channel partial waves f{sup 0}{sub +}(t), f{sup 1}{sub {+-}}(t). The recent status of this ongoing effort is presented.
Near-surface compressional and shear wave speeds constrained by body-wave polarization analysis
Park, Sunyoung; Ishii, Miaki
2018-06-01
A new technique to constrain near-surface seismic structure that relates body-wave polarization direction to the wave speed immediately beneath a seismic station is presented. The P-wave polarization direction is only sensitive to shear wave speed but not to compressional wave speed, while the S-wave polarization direction is sensitive to both wave speeds. The technique is applied to data from the High-Sensitivity Seismograph Network in Japan, and the results show that the wave speed estimates obtained from polarization analysis are compatible with those from borehole measurements. The lateral variations in wave speeds correlate with geological and physical features such as topography and volcanoes. The technique requires minimal computation resources, and can be used on any number of three-component teleseismic recordings, opening opportunities for non-invasive and inexpensive study of the shallowest (˜100 m) crustal structures.
International Nuclear Information System (INIS)
Garibotti, C.R.; Grinstein, F.F.
1978-01-01
Previous theorems on the convergence of the [n,n+m] punctual Pade approximants to the scattering amplitude are extended. The new proofs include the cases of nonforward and backward scattering corresponding to potentials having 1/r and 1/r 2 long-range behaviors, for which the partial wave expansions are divergent and oscillatory, respectively. In this way, the ability of the approximation scheme as a summation method is established for all of the long-range potentials of interest in potential scattering
International Nuclear Information System (INIS)
Garibotti, C.R.; Grinstein, F.F.
1978-01-01
Previous theorems on the convergence of the [n, n+m] Punctual Pade Approximants to the scattering amplitude are extended. The new proofs include the cases of non-forward and backward scattering corresponding to potentials having 1/r and 1/r 2 long range behaviours, for which the partial wave expansions are divergent and oscillatory, respectively. In this way, the ability of the approximation scheme as a summation method is established for all of the long range potentials of interest in potential scattering [pt
Economical analysis of the second partial reload for Angra 1 with partial low-leakage
International Nuclear Information System (INIS)
Mascarenhas, H.A.; Teixeira, M.C.C.; Dias, A.M.
1990-01-01
Preliminary results for the Angra 1 second reload design with partial low-leakage were assessed with NUCOST 1.0, code for nuclear power costs calculation. In the proposed scheme, some partially burned fuel assemblies (FAs) are located at the core boundary, while new FAs occupy more internal positions. The nuclear design - utilizing the code system SAV (from Siemens/KWU Group, F.R. Germany) - has been performed with detail for the 3rd cycle while simpler approach has been utilized for subsequent reloads. Results of NUCOST 1.0 show that the partial low-leakage reload in the 3rd cycle of Angra 1 offers fuel costs 1% lower when compared to the Plant's actual reload scheme, what corresponds to an savings of about US$190.000. When operation and maintenance and capital costs are also considered, economies in the order of US$2.6 million are obrained. (author) [pt
Partial correlation analysis method in ultrarelativistic heavy-ion collisions
Olszewski, Adam; Broniowski, Wojciech
2017-11-01
We argue that statistical data analysis of two-particle longitudinal correlations in ultrarelativistic heavy-ion collisions may be efficiently carried out with the technique of partial covariance. In this method, the spurious event-by-event fluctuations due to imprecise centrality determination are eliminated via projecting out the component of the covariance influenced by the centrality fluctuations. We bring up the relationship of the partial covariance to the conditional covariance. Importantly, in the superposition approach, where hadrons are produced independently from a collection of sources, the framework allows us to impose centrality constraints on the number of sources rather than hadrons, that way unfolding of the trivial fluctuations from statistical hadronization and focusing better on the initial-state physics. We show, using simulated data from hydrodynamics followed with statistical hadronization, that the technique is practical and very simple to use, giving insight into the correlations generated in the initial stage. We also discuss the issues related to separation of the short- and long-range components of the correlation functions and show that in our example the short-range component from the resonance decays is largely reduced by considering pions of the same sign. We demonstrate the method explicitly on the cases where centrality is determined with a single central control bin or with two peripheral control bins.
Vibration analysis of partially cracked plate submerged in fluid
Soni, Shashank; Jain, N. K.; Joshi, P. V.
2018-01-01
The present work proposes an analytical model for vibration analysis of partially cracked rectangular plates coupled with fluid medium. The governing equation of motion for the isotropic plate based on the classical plate theory is modified to accommodate a part through continuous line crack according to simplified line spring model. The influence of surrounding fluid medium is incorporated in the governing equation in the form of inertia effects based on velocity potential function and Bernoulli's equations. Both partially and totally submerged plate configurations are considered. The governing equation also considers the in-plane stretching due to lateral deflection in the form of in-plane forces which introduces geometric non-linearity into the system. The fundamental frequencies are evaluated by expressing the lateral deflection in terms of modal functions. The assessment of the present results is carried out for intact submerged plate as to the best of the author's knowledge the literature lacks in analytical results for submerged cracked plates. New results for fundamental frequencies are presented as affected by crack length, fluid level, fluid density and immersed depth of plate. By employing the method of multiple scales, the frequency response and peak amplitude of the cracked structure is analyzed. The non-linear frequency response curves show the phenomenon of bending hardening or softening and the effect of fluid dynamic pressure on the response of the cracked plate.
Attenuation Analysis of Lamb Waves Using the Chirplet Transform
Kerber, Florian; Sprenger, Helge; Niethammer, Marc; Luangvilai, Kritsakorn; Jacobs, Laurence J.
2010-01-01
Guided Lamb waves are commonly used in nondestructive evaluation to monitor plate-like structures or to characterize properties of composite or layered materials. However, the dispersive propagation and multimode excitability of Lamb waves complicate their analysis. Advanced signal processing
The Multi-Wave Method for Exact Solutions of Nonlinear Partial Differential Equations
Directory of Open Access Journals (Sweden)
Yusuf Pandir
2018-02-01
Full Text Available In this research, we use the multi-wave method to obtain new exact solutions for generalized forms of 5th order KdV equation and fth order KdV (fKdV equation with power law nonlinearity. Computations are performed with the help of the mathematics software Mathematica. Then, periodic wave solutions, bright soliton solutions and rational function solutions with free parameters are obtained by this approach. It is shown that this method is very useful and effective.
Heating and ionization in MHD shock waves propagating into partially ionized plasma
International Nuclear Information System (INIS)
Bighel, L.; Collins, A.R.; Cramer, N.F.; Watson-Munro, C.N.
1975-09-01
A model of the structure of MHD switch-on shocks propagating in a partially ionized plasma, in which the primary dissipation mechanism is friction between ions and neutrals, is here compared favourably with experimental results. Four degrees of upstream ionization were studied, ranging from almost complete to very small ionization. (author)
Heating and ionization in MHD shock wave propagating into partially ionized plasma
International Nuclear Information System (INIS)
Bighel, L.; Collins, A.R.; Cramer, N.F.; Watson-Munro, C.N.
1975-09-01
A model of the structure of MHD switch-on shocks propagating in a partially ionized plasma, in which the primary dissipation mechanism is friction between ions and neutrals, is here compared favourably with experimental results. Four degrees of upstream ionization were studied, ranging from almost complete to very small ionization. (author)
International Nuclear Information System (INIS)
Milde, T; Schwab, K; Walther, M; Eiselt, M; Witte, H; Schelenz, C; Voss, A
2011-01-01
Time-variant partial directed coherence (tvPDC) is used for the first time in a multivariate analysis of heart rate variability (HRV), respiratory movements (RMs) and (systolic) arterial blood pressure. It is shown that respiration-related HRV components which also occur at other frequencies besides the RM frequency (= respiratory sinus arrhythmia, RSA) can be identified. These additional components are known to be an effect of the 'half-the-mean-heart-rate-dilemma' ('cardiac aliasing' CA). These CA components may contaminate the entire frequency range of HRV and can lead to misinterpretation of the RSA analysis. TvPDC analysis of simulated and clinical data (full-term neonates and sedated patients) reveals these contamination effects and, in addition, the respiration-related CA components can be separated from the RSA component and the Traube–Hering–Mayer wave. It can be concluded that tvPDC can be beneficially applied to avoid misinterpretations in HRV analyses as well as to quantify partial correlative interaction properties between RM and RSA
Codina, R.; Ambrosini, D.
2018-03-01
For the last few decades, the effects of blast loading on structures have been studied by many researchers around the world. Explosions can be caused by events such as industrial accidents, military conflicts or terrorist attacks. Urban centers have been prone to various threats including car bombs, suicide attacks, and improvised explosive devices. Partially vented constructions subjected to external blast loading represent an important topic in protective engineering. The assessment of blast survivability inside structures and the development of design provisions with respect to internal elements require the study of the propagation and leakage of blast waves inside buildings. In this paper, full-scale tests are performed to study the effects of the leakage of blast waves inside a partially vented room that is subjected to different external blast loadings. The results obtained may be useful for proving the validity of different methods of calculation, both empirical and numerical. Moreover, the experimental results are compared with those computed using the empirical curves of the US Defense report/manual UFC 3-340. Finally, results of the dynamic response of the front masonry wall are presented in terms of accelerations and an iso-damage diagram.
Fermi wave vector for the partially spin-polarized composite-fermion Fermi sea
Balram, Ajit C.; Jain, J. K.
2017-12-01
The fully spin-polarized composite-fermion (CF) Fermi sea at the half-filled lowest Landau level has a Fermi wave vector kF*=√{4 π ρe } , where ρe is the density of electrons or composite fermions, supporting the notion that the interaction between composite fermions can be treated perturbatively. Away from ν =1 /2 , the area is seen to be consistent with kF*=√{4 π ρe } for ν 1 /2 , where ρh is the density of holes in the lowest Landau level. This result is consistent with particle-hole symmetry in the lowest Landau level. We investigate in this article the Fermi wave vector of the spin-singlet CF Fermi sea (CFFS) at ν =1 /2 , for which particle-hole symmetry is not a consideration. Using the microscopic CF theory, we find that for the spin-singlet CFFS the Fermi wave vectors for up- and down-spin CFFSs at ν =1 /2 are consistent with kF*↑,↓=√{4 π ρe↑,↓ } , where ρe↑=ρe↓=ρe/2 , which implies that the residual interactions between composite fermions do not cause a nonperturbative correction for spin-singlet CFFS either. Our results suggest the natural conjecture that for arbitrary spin polarization the CF Fermi wave vectors are given by kF*↑=√{4 π ρe↑ } and kF*↓=√{4 π ρe↓ } .
Potential and limitations of wave intensity analysis in coronary arteries
Siebes, M.; Kolyva, C.; Verhoeff, B.J.; Piek, J.J.; Spaan, J.A.
2009-01-01
Wave intensity analysis (WIA) is beginning to be applied to the coronary circulation both to better understand coronary physiology and as a diagnostic tool. Separation of wave intensity (WI) into forward and backward traveling components requires knowledge of pulse wave velocity at the point of
Assessing ground compaction via time lapse surface wave analysis
Czech Academy of Sciences Publication Activity Database
Dal Moro, Giancarlo; Al-Arifi, N.; Moustafa, S.S.R.
2016-01-01
Roč. 13, č. 3 (2016), s. 249-256 ISSN 1214-9705 Institutional support: RVO:67985891 Keywords : Full velocity spectrum (FVS) analysis * ground compaction * ground compaction * phase velocities * Rayleigh waves * seismic data inversion * surface wave dispersion * surface waves Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.699, year: 2016
Cheng, Xiangle; Blanchard, Antoine; Tan, Chin An; Lu, Huancai; Bergman, Lawrence A.; McFarland, D. Michael; Vakakis, Alexander F.
2017-12-01
The free and forced vibrations of a linear string with a local spring-damper on a partial elastic foundation, as well as a linear string on a viscoelastic foundation conceptualized as a continuous distribution of springs and dampers, are studied in this paper. Exact, analytical results are obtained for the free and forced response to a harmonic excitation applied at one end of the string. Relations between mode complexity and energy confinement with the dispersion in the string system are examined for the steady-state forced vibration, and numerical methods are applied to simulate the transient evolution of energy propagation. Eigenvalue loci veering and normal mode localization are observed for weakly coupled subsystems, when the foundation stiffness is sufficiently large, for both the spatially symmetric and asymmetric systems. The forced vibration results show that nonproportional damping-induced mode complexity, for which there are co-existing regions of purely traveling waves and standing waves, is attainable for the dispersive string system. However, this wave transition phenomenon depends strongly on the location of the attached discrete spring-damper relative to the foundation and whether the excitation frequency Ω is above or below the cutoff frequency ωc. When Ωcontrol strategies.
Trend analysis of wave storminess: wave direction and its impact on harbour agitation
Directory of Open Access Journals (Sweden)
M. Casas-Prat
2010-11-01
Full Text Available In the context of wave climate variability, long-term alterations in the wave storminess pattern of the Catalan coast (northwestern Mediterranean Sea are analysed in terms of wave energy content and wave direction, on the basis of wave hindcast data (from 44-year time series. In general, no significant temporal trends are found for annual mean and maximum energy. However, the same analysis carried out separately for different wave directions reveals a remarkable increase in the storm energy of events from the south, which is partly due to a rise in the annual percentage of such storms. A case study of Tarragona Port (on the southern Catalan coast highlights the importance of including changes in wave direction in the study of potential impacts of climate change. In particular, an increase in the frequency of storms from the south leads to greater agitation inside the Port.
CFD Analysis of Water Solitary Wave Reflection
Directory of Open Access Journals (Sweden)
K. Smida
2011-12-01
Full Text Available A new numerical wave generation method is used to investigate the head-on collision of two solitary waves. The reflection at vertical wall of a solitary wave is also presented. The originality of this model, based on the Navier-Stokes equations, is the specification of an internal inlet velocity, defined as a source line within the computational domain for the generation of these non linear waves. This model was successfully implemented in the PHOENICS (Parabolic Hyperbolic Or Elliptic Numerical Integration Code Series code. The collision of two counter-propagating solitary waves is similar to the interaction of a soliton with a vertical wall. This wave generation method allows the saving of considerable time for this collision process since the counter-propagating wave is generated directly without reflection at vertical wall. For the collision of two solitary waves, numerical results show that the run-up phenomenon can be well explained, the solution of the maximum wave run-up is almost equal to experimental measurement. The simulated wave profiles during the collision are in good agreement with experimental results. For the reflection at vertical wall, the spatial profiles of the wave at fixed instants show that this problem is equivalent to the collision process.
Wave-equation Migration Velocity Analysis Using Plane-wave Common Image Gathers
Guo, Bowen
2017-06-01
Wave-equation migration velocity analysis (WEMVA) based on subsurface-offset, angle domain or time-lag common image gathers (CIGs) requires significant computational and memory resources because it computes higher dimensional migration images in the extended image domain. To mitigate this problem, a WEMVA method using plane-wave CIGs is presented. Plane-wave CIGs reduce the computational cost and memory storage because they are directly calculated from prestack plane-wave migration, and the number of plane waves is often much smaller than the number of shots. In the case of an inaccurate migration velocity, the moveout of plane-wave CIGs is automatically picked by a semblance analysis method, which is then linked to the migration velocity update by a connective function. Numerical tests on two synthetic datasets and a field dataset validate the efficiency and effectiveness of this method.
Growth modeling of Cryptomeria japonica by partial trunk analysis
Directory of Open Access Journals (Sweden)
Vinícius Morais Coutinho
2017-06-01
Full Text Available This study aimed to evaluate the growth pattern of Cryptomeria japonica increment (L. F. D. Don. and to describe the probability distribution in stands stablished at the municipality of Rio Negro, Paraná State. Twenty trees were sampled in a 34 years-old stand, with 3 m x 2 m spacing. Wood disks were taken from each tree at 1.3 m above the ground (DBH to perform partial stem analysis. Diameter growth series without bark were used to generate the average cumulative growth curves for DBH (cm, mean annual increment (MAI and current annual increment (CAI. From the increment data, the frequency distribution was evaluated by means of probability density functions (pdfs. The mean annual increment for DBH was 0.78 cm year-1 and the age of intersection of CAI and MAI curves was between the 7th and 8th years. It was found that near 43% of the species increments are concentrated bellow 0.5 cm. The results are useful to define appropriate management strategies for the species for sites similar to the studying regions, defining for example ages of silvicultural intervention, such as thinning.
Wave energy patterns of counterpulsation: a novel approach with wave intensity analysis.
Lu, Pong-Jeu; Yang, Chi-Fu Jeffrey; Wu, Meng-Yu; Hung, Chun-Hao; Chan, Ming-Yao; Hsu, Tzu-Cheng
2011-11-01
In counterpulsation, diastolic augmentation increases coronary blood flow and systolic unloading reduces left ventricular afterload. We present a new approach with wave intensity analysis to revisit and explain counterpulsation principles. In an acute porcine model, a standard intra-aortic balloon pump was placed in descending aorta in 4 pigs. We measured pressure and velocity with probes in left anterior descending artery and aorta during and without intra-aortic balloon pump assistance. Wave intensities of aortic and left coronary waves were derived from pressure and flow measurements with synchronization correction. We identified predominating waves in counterpulsation. In the aorta, during diastolic augmentation, intra-aortic balloon inflation generated a backward compression wave, with a "pushing" effect toward the aortic root that translated to a forward compression wave into coronary circulation. During systolic unloading, intra-aortic balloon pump deflation generated a backward expansion wave that "sucked" blood from left coronary bed into the aorta. While this backward expansion wave translated to reduced left ventricular afterload, the "sucking" effect resulted in left coronary blood steal, as demonstrated by a forward expansion wave in left anterior descending coronary flow. The waves were sensitive to inflation and deflation timing, with just 25 ms delay from standard deflation timing leading to weaker forward expansion wave and less coronary regurgitation. Intra-aortic balloon pumps generate backward-traveling waves that predominantly drive aortic and coronary blood flow during counterpulsation. Wave intensity analysis of arterial circulations may provide a mechanism to explain diastolic augmentation and systolic unloading of intra-aortic balloon pump counterpulsation. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Chen, Pengzhen; Wang, Xiaoqing; Liu, Li; Chong, Jinsong
2016-06-01
According to Bragg theory, capillary waves are the predominant scatterers of high-frequency band (such as Ka-band) microwave radiation from the surface of the ocean. Therefore, understanding the modulation mechanism of capillary waves is an important foundation for interpreting high-frequency microwave remote sensing images of the surface of the sea. In our experiments, we discovered that modulations of capillary waves are significantly larger than the values predicted by the classical theory. Further, analysis shows that the difference in restoring force results in an inflection point while the phase velocity changes from gravity waves region to capillary waves region, and this results in the capillary waves being able to resonate with gravity waves when the phase velocity of the gravity waves is equal to the group velocity of the capillary waves. Consequently, we propose a coupling modulation model in which the current modulates the capillary wave indirectly by modulating the resonant gravity waves, and the modulation of the former is approximated by that of the latter. This model very effectively explains the results discovered in our experiments. Further, based on Bragg scattering theory and this coupling modulation model, we simulate the modulation of normalized radar cross section (NRCS) of typical internal waves and show that the high-frequency bands are superior to the low-frequency bands because of their greater modulation of NRCS and better radiometric resolution. This result provides new support for choice of radar band for observation of wave-current modulation oceanic phenomena such as internal waves, fronts, and shears.
Buckling analysis of partially corroded steel plates with irregular ...
Indian Academy of Sciences (India)
Department of Ocean Engineering, AmirKabir University of Technology, ... could yield some acceptance criteria to assist surveyors or designers in repair and .... Finite element model of a partially both-sided corroded plate (shell elements).
A time-frequency analysis of wave packet fractional revivals
International Nuclear Information System (INIS)
Ghosh, Suranjana; Banerji, J
2007-01-01
We show that the time-frequency analysis of the autocorrelation function is, in many ways, a more appropriate tool to resolve fractional revivals of a wave packet than the usual time-domain analysis. This advantage is crucial in reconstructing the initial state of the wave packet when its coherent structure is short-lived and decays before it is fully revived. Our calculations are based on the model example of fractional revivals in a Rydberg wave packet of circular states. We end by providing an analytical investigation which fully agrees with our numerical observations on the utility of time-frequency analysis in the study of wave packet fractional revivals
Numerical Analysis for Stochastic Partial Differential Delay Equations with Jumps
Li, Yan; Hu, Junhao
2013-01-01
We investigate the convergence rate of Euler-Maruyama method for a class of stochastic partial differential delay equations driven by both Brownian motion and Poisson point processes. We discretize in space by a Galerkin method and in time by using a stochastic exponential integrator. We generalize some results of Bao et al. (2011) and Jacob et al. (2009) in finite dimensions to a class of stochastic partial differential delay equations with jumps in infinite dimensions.
Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis
Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.
2016-01-01
Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.
Comparative videostroboscopic analysis after different external partial laryngectomies
Directory of Open Access Journals (Sweden)
Mumović Gordana M.
2014-01-01
Full Text Available Background/Aim. After external partial laryngectomias, videostroborscopy is very usefull in evaluation of postoperative phonatory mehanisms showing the “slow motion” of the vibrations of the remaining laryngeal structures. The aim of this paper was to compare the videostroboscopic characteristics of the vibration and to establish the differences in the phonation mechanisms depending on the type of external partial laryngectomy performed. Methods. This prospective study was conducted during the period 2003-2009 at the Ear, Nose and Throat Clinic, Clinical Center of Vojvodina, Novi Sad, including 99 patients with laryngeal carcinoma, treated with open surgical approach using different types of vertical and horizontal partial laryngectomy. Videostroboscopy was used to analyse vibrations of the remaining laryngeal structures. Results. The dominant vibration structure after partial horizontal laryngectomy, chordectomy, frontolateral laryngectomy and three quarter laryngectomy was the remaining vocal fold, after hemilaryngectomy it was the false vocal fold and after subtotal and near total laryngectomy it was the arythenoid. In patients with supracricoid hemilaryngopharyngectomy performed, many different structures were involved in the vibration. After most of the partial laryngectomies, vibrations can be found in the reconstructed part of the defect. In both horizontal and vertical partial laryngectomies movements of the larynx during phonation were mostly medial, while in cricohyoidoglottopexies they were anterior-posterior. Most of the operated patients (72.7% had insufficient occlusion of the neoglottis during the phonation. Conclusion. Videostroboscopy is a useful method in examining the phonation mechanisms of reconstructed laryngeal structures after partial laryngectomy as well as in planning postoperative voice therapy.
Directory of Open Access Journals (Sweden)
Radović Katarina
2010-01-01
Full Text Available Introduction. Various mobile devices are used in the therapy of unilateral free-end saddle. Unilateral dentures with precise connectivity elements are not used frequently. In this paper the problem of applying and functionality of unilateral freeend saddle denture without major connector was taken into consideration. Objective. The aim was to analyze and compare a unilateral RPD (removable partial denture and a classical RPD by calculating and analyzing stresses under different loads. Methods. 3D models of unilateral removable partial denture and classical removable partial denture with casted clasps were made by using computer program CATIA V5 (abutment teeth, canine and first premolar, with crowns and abutment tissues were also made. The models were built in full-scale. Stress analyses for both models were performed by applying a force of 300 N on the second premolar, a force of 500 N on the first molar and a force of 700 N on the second molar. Results. The Fault Model Extractor (FME analysis and calculation showed the complete behavior of unilateral removable partial denture and abutments (canine and first premolar, as well as the behavior of RPD under identical loading conditions. Applied forces with extreme values caused high stress levels on both models and their abutments within physiological limits. Conclusion. Having analyzed stresses under same conditions, we concluded that the unilateral RPD and classical RPD have similar physiological values.
Energy Technology Data Exchange (ETDEWEB)
Ivanov, S.T.; Nikolov, N.A.
1979-01-01
The problem of the excitation of microwaves during the propagation of a relativistic electron beam through a waveguide which is partially filled with a dielectric is solved using Maxwell equations and relativistic magnetic hydrodynamics. Two cases are found in which the beam-excited wave has a single mode (it is coherent). For one of the coherent waves, the saturation amplitude and the efficiency of converting the beam energy into electomagnetic field energy are determined.
Analysis of supercritical vapor explosions using thermal detonation wave theory
Energy Technology Data Exchange (ETDEWEB)
Shamoun, B.I.; Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)
1995-09-01
The interaction of certain materials such as Al{sub 2}O{sub 3} with water results in vapor explosions with very high (supercritical) pressures and propagation velocities. A quasi-steady state analysis of supercritical detonation in one-dimensional multiphase flow was applied to analyze experimental data of the KROTOS (26-30) set of experiments conducted at the Joint Research Center at Ispra, Italy. In this work we have applied a new method of solution which allows for partial fragmentation of the fuel in the shock adiabatic thermodynamic model. This method uses known experiment values of the shock pressure and propagation velocity to estimate the initial mixing conditions of the experiment. The fuel and coolant were both considered compressible in this analysis. In KROTOS 26, 28, 29, and 30 the measured values of the shock pressure by the experiment were found to be higher than 25, 50, 100, and 100 Mpa respectively. Using the above data for the wave velocity and our best estimate for the values of the pressure, the predicted minimum values of the fragmented mass of the fuel were found to be 0.026. 0.04, 0.057, and 0.068 kg respectively. The predicted values of the work output corresponding to the above fragmented masses of the fuel were found to be 40, 84, 126, and 150 kJ respectively, with predicted initial void fractions of 112%, 12.5%, 8%, and 6% respectively.
Wave-equation Migration Velocity Analysis Using Plane-wave Common Image Gathers
Guo, Bowen; Schuster, Gerard T.
2017-01-01
Wave-equation migration velocity analysis (WEMVA) based on subsurface-offset, angle domain or time-lag common image gathers (CIGs) requires significant computational and memory resources because it computes higher dimensional migration images
PDASAC, Partial Differential Sensitivity Analysis of Stiff System
International Nuclear Information System (INIS)
Caracotsios, M.; Stewart, W.E.
2001-01-01
1 - Description of program or function: PDASAC solves stiff, nonlinear initial-boundary-value problems in a timelike dimension t and a space dimension x. Plane, circular cylindrical or spherical boundaries can be handled. Mixed-order systems of partial differential and algebraic equations can be analyzed with members of order or 0 or 1 in t, 0, 1 or 2 in x. Parametric sensitivities of the calculated states are computed simultaneously on request, via the Jacobian of the state equations. Initial and boundary conditions are efficiently reconciled. Local error control (in the max-norm or the 2-norm) is provided for the state vector and can include the parametric sensitivities if desired. 2 - Method of solution: The method of lines is used, with a user- selected x-grid and a minimum-bandwidth finite-difference approximations of the x-derivatives. Starting conditions are reconciled with a damped Newton algorithm adapted from Bain and Stewart (1991). Initial step selection is done by the first-order algorithms of Shampine (1987), extended here to differential- algebraic equation systems. The solution is continued with the DASSL predictor-corrector algorithm (Petzold 1983, Brenan et al. 1989) with the initial acceleration phase deleted and with row scaling of the Jacobian added. The predictor and corrector are expressed in divided-difference form, with the fixed-leading-coefficient form of corrector (Jackson and Sacks-Davis 1989; Brenan et al. 1989). Weights for the error tests are updated in each step with the user's tolerances at the predicted state. Sensitivity analysis is performed directly on the corrector equations of Caracotsios and Stewart (1985) and is extended here to the initialization when needed. 3 - Restrictions on the complexity of the problem: This algorithm, like DASSL, performs well on differential-algebraic equation systems of index 0 and 1 but not on higher-index systems; see Brenan et al. (1989). The user assigned the work array lengths and the output
Theory analysis and simple calculation of travelling wave burnup scheme
International Nuclear Information System (INIS)
Zhang Jian; Yu Hong; Gang Zhi
2012-01-01
Travelling wave burnup scheme is a new burnup scheme that breeds fuel locally just before it burns. Based on the preliminary theory analysis, the physical imagine was found. Through the calculation of a R-z cylinder travelling wave reactor core with ERANOS code system, the basic physical characteristics of this new burnup scheme were concluded. The results show that travelling wave reactor is feasible in physics, and there are some good features in the reactor physics. (authors)
Mountain Wave Analysis Using Fourier Methods
National Research Council Canada - National Science Library
Roadcap, John R
2007-01-01
...) their requirements for only a coarse horizontal background state. Common traits of Fourier mountain wave models include use of the Boussinesq approximation and neglect of moisture and Coriolis terms...
Analysis of Z Pinch Shock Wave Experiments
International Nuclear Information System (INIS)
Asay, James; Budge, Kent G.; Chandler, Gordon; Fleming, Kevin; Hall, Clint; Holland, Kathleen; Konrad, Carl; Lawrence, Jeffery; Trott, Wayne; Trucano, Timothy
1999-01-01
In this paper, we report details of our computational study of two shock wave physics experiments performed on the Sandia Z machine in 1998. The novelty of these particular experiments is that they represent the first successful application of VISAR interferometry to diagnose shock waves generated in experimental payloads by the primary X-ray pulse of the machine. We use the Sandia shock-wave physics code ALEGRA to perform the simulations reported in this study. Our simulations are found to be in fair agreement with the time-resolved VISAR experimental data. However, there are also interesting and important discrepancies. We speculate as to future use of time-resolved shock wave data to diagnose details of the Z machine X-ray pulse in the future
Partial-wave analyses of hadron scattering below 2 GeV
International Nuclear Information System (INIS)
Arndt, R.A.; Roper, L.D.
1990-01-01
The Center for Analysis of Particle Scattering (CAPS) in the Department of Physics at Virginia Polytechnic Institute and State University has analyzed basic two-body hadron reactions below 2 GeV for the last two decades. Reactions studied were nucleon-nucleon, pion-nucleon, K + -nucleon and pion photoproduction systems. In addition to analyses of these systems, a computer graphics system (SAID) has been developed and disseminated to over 200 research institutions using VAX computers. 8 refs
Partial-wave analyses of hadron scattering below 2 GeV
International Nuclear Information System (INIS)
Arndt, R.A.; Roper, L.D.
1991-01-01
The Center for Analysis of Particle Scattering (CAPS) in the Department of Physics at Virginia Polytechnic Institute and State University has analyzed basic two-body hadron reactions below 2 GeV for the last two decades. Reactions studied were nucleon-nucleon, pion-nucleon, K + -nucleon and pion photoproduction systems. In addition to analyses of these systems, a computer graphics system (SAID) has been developed and disseminated to over 250 research institutions using VAX computers. The computer-interactive system for disseminating information on basic scattering reactions is also accessible to the physics community through TELNET on the VPI ampersand SU physics department VAX. 6 refs
Radiographic analysis of partial or total vertebral body resection
International Nuclear Information System (INIS)
Whitten, C.G.; Hammer, G.H.; El-Khoury, G.Y.; Hugus, J.; Weinstein, J.N.
1991-01-01
Partial and total vertebrectomies are used in the treatment of primary and metastatic neoplasms of the spine. Serial radiographic studies are crucial in the follow-up of patients with vertebrectomies. This paper presents 33 cases and illustrates radiographic examples of both successful and complicated vertebrectomies, including radiographic signs of local tumor recurrence, loosening, migration or fracture of the hardware or methylmethacrylate, bone graft failure, and progressive spinal instability
3D Guided Wave Motion Analysis on Laminated Composites
Tian, Zhenhua; Leckey, Cara; Yu, Lingyu
2013-01-01
Ultrasonic guided waves have proved useful for structural health monitoring (SHM) and nondestructive evaluation (NDE) due to their ability to propagate long distances with less energy loss compared to bulk waves and due to their sensitivity to small defects in the structure. Analysis of actively transmitted ultrasonic signals has long been used to detect and assess damage. However, there remain many challenging tasks for guided wave based SHM due to the complexity involved with propagating guided waves, especially in the case of composite materials. The multimodal nature of the ultrasonic guided waves complicates the related damage analysis. This paper presents results from parallel 3D elastodynamic finite integration technique (EFIT) simulations used to acquire 3D wave motion in the subject laminated carbon fiber reinforced polymer composites. The acquired 3D wave motion is then analyzed by frequency-wavenumber analysis to study the wave propagation and interaction in the composite laminate. The frequency-wavenumber analysis enables the study of individual modes and visualization of mode conversion. Delamination damage has been incorporated into the EFIT model to generate "damaged" data. The potential for damage detection in laminated composites is discussed in the end.
Topics in the Analysis of Shear-Wave Propagation in Oblique-Plate Impact Tests
National Research Council Canada - National Science Library
Scheidler, Mike
2007-01-01
This report addresses several topics in the theoretical analysis of shock waves, acceleration waves, and centered simple waves, with emphasis on the propagation of shear waves generated in oblique-plate impact tests...
DANWEC - Empirical Analysis of the Wave Climate at the Danish Wave Energy Centre
DEFF Research Database (Denmark)
Tetu, Amelie; Nielsen, Kim; Kofoed, Jens Peter
information on the DanWEC wave and current climate. In this paper an analysis of the wave climate of the DanWEC test site will be presented. This includes a description of the data quality control and filtration for analysis and the observations and data analysis. Relevant characteristics of the test site...... site for several Danish WECs. In 2013 DanWEC has received Greenlab funding from the EUDP programme to establish the site including more detailed information on its wave climate and bathymetry and seabed conditions. The project “Resource Assessment, Forecasts and WECs O&M strategies at DanWEC and beyond......, as for example scatter diagram (Hm0, Tz) will be analysed and wave power distribution given. Based on the data gathered so far a preliminary analysis of extreme events at the DanWEC test site will be presented. Deployment, control strategies and O&M strategies of wave energy converters are sensitive to the wave...
Spectral analysis of surface waves method to assess shear wave velocity within centrifuge models
MURILLO, Carol Andrea; THOREL, Luc; CAICEDO, Bernardo
2009-01-01
The method of the spectral analysis of surface waves (SASW) is tested out on reduced scale centrifuge models, with a specific device, called the mini Falling Weight, developed for this purpose. Tests are performed on layered materials made of a mixture of sand and clay. The shear wave velocity VS determined within the models using the SASW is compared with the laboratory measurements carried out using the bender element test. The results show that the SASW technique applied to centrifuge test...
Analysis of sediment particle velocity in wave motion based on wave flume experiments
Krupiński, Adam
2012-10-01
The experiment described was one of the elements of research into sediment transport conducted by the Division of Geotechnics of West-Pomeranian University of Technology. The experimental analyses were performed within the framework of the project "Building a knowledge transfer network on the directions and perspectives of developing wave laboratory and in situ research using innovative research equipment" launched by the Institute of Hydroengineering of the Polish Academy of Sciences in Gdańsk. The objective of the experiment was to determine relations between sediment transport and wave motion parameters and then use the obtained results to modify formulas defining sediment transport in rivers, like Ackers-White formula, by introducing basic parameters of wave motion as the force generating bed material transport. The article presents selected results of the experiment concerning sediment velocity field analysis conducted for different parameters of wave motion. The velocity vectors of particles suspended in water were measured with a Particle Image Velocimetry (PIV) apparatus registering suspended particles in a measurement flume by producing a series of laser pulses and analysing their displacement with a high-sensitivity camera connected to a computer. The article presents velocity fields of suspended bed material particles measured in the longitudinal section of the wave flume and their comparison with water velocity profiles calculated for the definite wave parameters. The results presented will be used in further research for relating parameters essential for the description of monochromatic wave motion to basic sediment transport parameters and "transforming" mean velocity and dynamic velocity in steady motion to mean wave front velocity and dynamic velocity in wave motion for a single wave.
Geodesics analysis of colliding gravitational shock waves
International Nuclear Information System (INIS)
Pozdeeva, E.
2011-01-01
Full text: (author)We consider collision of charged gravitational shock waves with infinite transverse extension (charged gravitational walls). We study the influence of the charges on the trapped surface formation in the charged walls collision. This consideration has applications in the in heavy ion collisions using a holographic approach in which the charge plays the role of the chemical potential
Preliminary Analysis of a Submerged Wave Energy Device
Wagner, J. R.; Wagner, J. J.; Hayatdavoodi, M.; Ertekin, R. C.
2016-02-01
Preliminary analysis of a submerged wave energy harvesting device is presented. The device is composed of a thin, horizontally submerged plate that is restricted to heave oscillations under the influence of surface waves. The submerged plate is oscillating, and it can be attached to a fixed rotor, or a piston, to harvest the wave energy. A fully submerged wave energy converter is preferred over a surface energy convertor due to its durability and less visual and physical distractions it presents. In this study, the device is subject to nonlinear shallow-water waves. Wave loads on the submerged oscillating plate are obtained via the Level I Green-Naghdi equations. The unsteady motion of the plate is obtained by solving the nonlinear equations of motion. The results are obtained for a range of waves with varying heights and periods. The amplitude and period of plate oscillations are analyzed as functions of the wave parameters and plate width. Particular attention is given to the selection of the site of desired wave field. Initial estimation on the amount of energy extraction from the device, located near shore at a given site, is provided.
Two dimensional kinetic analysis of electrostatic harmonic plasma waves
Energy Technology Data Exchange (ETDEWEB)
Fonseca-Pongutá, E. C.; Ziebell, L. F.; Gaelzer, R. [Instituto de Física, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); SSR, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of)
2016-06-15
Electrostatic harmonic Langmuir waves are virtual modes excited in weakly turbulent plasmas, first observed in early laboratory beam-plasma experiments as well as in rocket-borne active experiments in space. However, their unequivocal presence was confirmed through computer simulated experiments and subsequently theoretically explained. The peculiarity of harmonic Langmuir waves is that while their existence requires nonlinear response, their excitation mechanism and subsequent early time evolution are governed by essentially linear process. One of the unresolved theoretical issues regards the role of nonlinear wave-particle interaction process over longer evolution time period. Another outstanding issue is that existing theories for these modes are limited to one-dimensional space. The present paper carries out two dimensional theoretical analysis of fundamental and (first) harmonic Langmuir waves for the first time. The result shows that harmonic Langmuir wave is essentially governed by (quasi)linear process and that nonlinear wave-particle interaction plays no significant role in the time evolution of the wave spectrum. The numerical solutions of the two-dimensional wave spectra for fundamental and harmonic Langmuir waves are also found to be consistent with those obtained by direct particle-in-cell simulation method reported in the literature.
Contrast analysis of the partial splenic artery embolization with splenectomy
International Nuclear Information System (INIS)
Lu Wusheng; He Qing; Zheng Zhiyong; Wu Shaoping; Xu Dawei
2006-01-01
Objective: To analyze the effects and the complications of partial splenic artery embolization (PSE) and splenectomy offering a feasible way to choose different therapeutic methods for hypersplenism. Methods: Forty-six patients treated with PSE and thirty-three undergone splenectomy were compared for their effectivenesses and complications in treating hypersplenism. Results: Thrombocyte and leucocyte counts increased markedly after the two kinds of treatment (P 0.05). The complication rate of the PSE was far more than that of the splenectomy (P<0.001). Conclusions Splenectomy is prior to PSE on patients with large mount of ascites, serious portal hypertension and splenomegaly. PSE is suitable for patients with poor liver function, blood coagulation disturbance, liver cancer complicated with hypersplenism and aging. (authors)
Stepwise Analysis of Differential Item Functioning Based on Multiple-Group Partial Credit Model.
Muraki, Eiji
1999-01-01
Extended an Item Response Theory (IRT) method for detection of differential item functioning to the partial credit model and applied the method to simulated data using a stepwise procedure. Then applied the stepwise DIF analysis based on the multiple-group partial credit model to writing trend data from the National Assessment of Educational…
Analysis shear wave velocity structure obtained from surface wave methods in Bornova, Izmir
Energy Technology Data Exchange (ETDEWEB)
Pamuk, Eren, E-mail: eren.pamuk@deu.edu.tr; Akgün, Mustafa, E-mail: mustafa.akgun@deu.edu.tr [Department of Geophysical Engineering, Dokuz Eylul University, Izmir (Turkey); Özdağ, Özkan Cevdet, E-mail: cevdet.ozdag@deu.edu.tr [Dokuz Eylul University Rectorate, Izmir (Turkey)
2016-04-18
Properties of the soil from the bedrock is necessary to describe accurately and reliably for the reduction of earthquake damage. Because seismic waves change their amplitude and frequency content owing to acoustic impedance difference between soil and bedrock. Firstly, shear wave velocity and depth information of layers on bedrock is needed to detect this changing. Shear wave velocity can be obtained using inversion of Rayleigh wave dispersion curves obtained from surface wave methods (MASW- the Multichannel Analysis of Surface Waves, ReMi-Refraction Microtremor, SPAC-Spatial Autocorrelation). While research depth is limeted in active source study, a passive source methods are utilized for deep depth which is not reached using active source methods. ReMi method is used to determine layer thickness and velocity up to 100 m using seismic refraction measurement systems.The research carried out up to desired depth depending on radius using SPAC which is utilized easily in conditions that district using of seismic studies in the city. Vs profiles which are required to calculate deformations in under static and dynamic loads can be obtained with high resolution using combining rayleigh wave dispersion curve obtained from active and passive source methods. In the this study, Surface waves data were collected using the measurements of MASW, ReMi and SPAC at the İzmir Bornova region. Dispersion curves obtained from surface wave methods were combined in wide frequency band and Vs-depth profiles were obtained using inversion. Reliability of the resulting soil profiles were provided by comparison with theoretical transfer function obtained from soil paremeters and observed soil transfer function from Nakamura technique and by examination of fitting between these functions. Vs values are changed between 200-830 m/s and engineering bedrock (Vs>760 m/s) depth is approximately 150 m.
Analysis of seismic waves and strong ground motion
International Nuclear Information System (INIS)
Simpson, I.C.; Sutton, R.
1976-10-01
A number of Western USA earthquake acceleration-time histories concerning events of magnitude less than 6 are considered and their Fourier spectra calculated. An analysis of some of the simpler types of seismic wave is given in order to consider the generation of a spatially dependent acceleration-time history suitable for input into a soil-structure program of analysis. Such an acceleration-time history is required by a comprehensive analysis of soil-structure interaction since the conventionally assumed model of vertically propagating seismic waves, which give rise to three spatially independent ground motions, can lead to over-conservative estimates of the building response in the high frequency range. The possible application is discussed of a given component of a recorded acceleration-time history to the base of structure under the assumption of surface Rayleigh waves or obliquely incident P and SV bulk waves. (author)
Optimizing detection and analysis of slow waves in sleep EEG.
Mensen, Armand; Riedner, Brady; Tononi, Giulio
2016-12-01
Analysis of individual slow waves in EEG recording during sleep provides both greater sensitivity and specificity compared to spectral power measures. However, parameters for detection and analysis have not been widely explored and validated. We present a new, open-source, Matlab based, toolbox for the automatic detection and analysis of slow waves; with adjustable parameter settings, as well as manual correction and exploration of the results using a multi-faceted visualization tool. We explore a large search space of parameter settings for slow wave detection and measure their effects on a selection of outcome parameters. Every choice of parameter setting had some effect on at least one outcome parameter. In general, the largest effect sizes were found when choosing the EEG reference, type of canonical waveform, and amplitude thresholding. Previously published methods accurately detect large, global waves but are conservative and miss the detection of smaller amplitude, local slow waves. The toolbox has additional benefits in terms of speed, user-interface, and visualization options to compare and contrast slow waves. The exploration of parameter settings in the toolbox highlights the importance of careful selection of detection METHODS: The sensitivity and specificity of the automated detection can be improved by manually adding or deleting entire waves and or specific channels using the toolbox visualization functions. The toolbox standardizes the detection procedure, sets the stage for reliable results and comparisons and is easy to use without previous programming experience. Copyright © 2016 Elsevier B.V. All rights reserved.
Dispersive Wave Analysis Using the Chirplet Transform
International Nuclear Information System (INIS)
Kerber, Florian; Luangvilai, Kritsakorn; Kuttig, Helge; Niethammer, Marc; Jacobs, Laurence J.
2007-01-01
Time-frequency representations (TFR) are a widely used tool to analyze signals of guided waves such as Lamb waves. As a consequence of the uncertainty principle, however, the resolution in time and frequency is limited for all existing TFR methods. Due to the multi-modal and dispersive character of Lamb waves, displacement or energy related quantities can only be allocated to individual modes when they are well-separated in the time-frequency plane.The chirplet transform (CT) has been introduced as a generalization of both the wavelet and Short-time Fourier transform (STFT). It offers additional degrees of freedom to adjust time-frequency atoms which can be exploited in a model-based approach to match the group delay of individual modes. Thus, more exact allocation of quantities of interest is possible.The objective of this research is to use a previously developed adaptive algorithm based on the CT for nondestructive evaluation. Both numerically and experimentally generated data for a single aluminum plate is analyzed to determine the accuracy and robustness of the new method in comparison the classical STFT
Physics Structure Analysis of Parallel Waves Concept of Physics Teacher Candidate
International Nuclear Information System (INIS)
Sarwi, S; Linuwih, S; Supardi, K I
2017-01-01
The aim of this research was to find a parallel structure concept of wave physics and the factors that influence on the formation of parallel conceptions of physics teacher candidates. The method used qualitative research which types of cross-sectional design. These subjects were five of the third semester of basic physics and six of the fifth semester of wave course students. Data collection techniques used think aloud and written tests. Quantitative data were analysed with descriptive technique-percentage. The data analysis technique for belief and be aware of answers uses an explanatory analysis. Results of the research include: 1) the structure of the concept can be displayed through the illustration of a map containing the theoretical core, supplements the theory and phenomena that occur daily; 2) the trend of parallel conception of wave physics have been identified on the stationary waves, resonance of the sound and the propagation of transverse electromagnetic waves; 3) the influence on the parallel conception that reading textbooks less comprehensive and knowledge is partial understanding as forming the structure of the theory. (paper)
Energy Technology Data Exchange (ETDEWEB)
Clegg, Samuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Sklute, Elizabeth [MT HOLYOKE COLLEGE; Dyare, Melinda D [MT HOLYOKE COLLEGE
2008-01-01
Quantitative analysis with LIBS traditionally employs calibration curves that are complicated by the chemical matrix effects. These chemical matrix effects influence the LIBS plasma and the ratio of elemental composition to elemental emission line intensity. Consequently, LIBS calibration typically requires a priori knowledge of the unknown, in order for a series of calibration standards similar to the unknown to be employed. In this paper, three new Multivariate Analysis (MV A) techniques are employed to analyze the LIBS spectra of 18 disparate igneous and highly-metamorphosed rock samples. Partial Least Squares (PLS) analysis is used to generate a calibration model from which unknown samples can be analyzed. Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) are employed to generate a model and predict the rock type of the samples. These MV A techniques appear to exploit the matrix effects associated with the chemistries of these 18 samples.
Analysis of partial and total inelasticities obtained from inclusive reactions
International Nuclear Information System (INIS)
Bellandi, J.; Covolan, R.; Costa, C.G.; Montanha, J.; Mundim, L.M.
1994-01-01
An independent analysis of model for energetic dependence on inelasticity is presented, from experimental data of pp → c X (c = π +- , Κ +- , p +- ) type inclusive reactions. 6 refs., 2 figs., 1 tab
Directory of Open Access Journals (Sweden)
Franz Konstantin Fuss
2013-09-01
Full Text Available This paper is a theoretical analysis of mirror tilt in a Michelson interferometer and its effect on the radiant flux over the active area of a rectangular photodetector or image sensor pixel. It is relevant to sensor applications using homodyne interferometry where these opto-electronic devices are employed for partial fringe counting. Formulas are derived for radiant flux across the detector for variable location within the fringe pattern and with varying wave front angle. The results indicate that the flux is a damped sine function of the wave front angle, with a decay constant of the ratio of wavelength to detector width. The modulation amplitude of the dynamic fringe pattern reduces to zero at wave front angles that are an integer multiple of this ratio and the results show that the polarity of the radiant flux changes exclusively at these multiples. Varying tilt angle causes radiant flux oscillations under an envelope curve, the frequency of which is dependent on the location of the detector with the fringe pattern. It is also shown that a fringe count of zero can be obtained for specific photodetector locations and wave front angles where the combined effect of fringe contraction and fringe tilt can have equal and opposite effects. Fringe tilt as a result of a wave front angle of 0.05° can introduce a phase measurement difference of 16° between a photodetector/pixel located 20 mm and one located 100 mm from the optical origin.
Linear and nonlinear analysis of density wave instability phenomena
International Nuclear Information System (INIS)
Ambrosini, Walter
1999-01-01
In this paper the mechanism of density-wave oscillations in a boiling channel with uniform and constant heat flux is analysed by linear and nonlinear analytical tools. A model developed on the basis of a semi-implicit numerical discretization of governing partial differential equations is used to provide information on the transient distribution of relevant variables along the channel during instabilities. Furthermore, a lumped parameter model and a distributed parameter model developed in previous activities are also adopted for independent confirmation of the observed trends. The obtained results are finally put in relation with the picture of the phenomenon proposed in classical descriptions. (author)
Transient Analysis of Monopile Foundations Partially Embedded in Liquefied Soil
DEFF Research Database (Denmark)
Barari, Amin; Bayat, Mehdi; Meysam, Saadati
2015-01-01
Lagrangian Analysis of Continua (FLAC), which captured the fundamental mechanisms of the monopiles in saturated granular soil. The effects of inertia and the kinematic flow of soil are investigated separately, to highlight the importance of considering the combined effect of these phenomena on the seismic...
Partial Derivative Games in Thermodynamics: A Cognitive Task Analysis
Kustusch, Mary Bridget; Roundy, David; Dray, Tevian; Manogue, Corinne A.
2014-01-01
Several studies in recent years have demonstrated that upper-division students struggle with the mathematics of thermodynamics. This paper presents a task analysis based on several expert attempts to solve a challenging mathematics problem in thermodynamics. The purpose of this paper is twofold. First, we highlight the importance of cognitive task…
Analysis of a cylindrical imploding shock wave
International Nuclear Information System (INIS)
Mishkin, E.A.; Fujimoto, Y.
1978-01-01
the self-similar solution of the gasdynamic equations of a strong cylindrical shock wave moving through an ideal gas, with γ = csub(p)/csub(v), is considered. These equations are greatly simplified following the transformation of the reduced velocity U 1 (xi) → U 1 = 1/2(γ + 1 ) (U + xi). The requirement of a single maximum pressure, dsub(xi)P = 0, leads to an analytical determination of the self-similarity exponent α(γ). For gases with γ = 2 + 3sup(1/2), this maximum ensues right at the shock front and the pressure distribution then decreases monotonically. The postulate of analyticity by Gelfand and Butler is shown to concur with the requirement dsub(xi)P 0. The saturated density of the gas left in the wake of the shock is computed and - U is shown to be the reduced velocity of sound at P = P sub(m). (author)
Reliability Analysis of Dynamic Stability in Waves
DEFF Research Database (Denmark)
Søborg, Anders Veldt
2004-01-01
exhibit sufficient characteristics with respect to slope at zero heel (GM value), maximum leverarm, positive range of stability and area below the leverarm curve. The rule-based requirements to calm water leverarm curves are entirely based on experience obtained from vessels in operation and recorded......The assessment of a ship's intact stability is traditionally based on a semi-empirical deterministic concept that evaluates the characteristics of ship's calm water restoring leverarm curves. Today the ship is considered safe with respect to dynamic stability if its calm water leverarm curves...... accidents in the past. The rules therefore only leaves little room for evaluation and improvement of safety of a ship's dynamic stability. A few studies have evaluated the probability of ship stability loss in waves using Monte Carlo simulations. However, since this probability may be in the order of 10...
Directory of Open Access Journals (Sweden)
Jun Zhang
2018-01-01
Full Text Available The single scattering of P- and SV-waves by a cylindrical fiber with a partially imperfect bonding to the surrounding matrix is investigated, which benefits the characterization of the behavior of elastic waves in composite materials. The imperfect interface is modelled by the spring model. To solve the corresponding single scattering problem, a collocation point (CP method is introduced. Based on this method, influence of various aspects of the imperfect interface on the scattering of P- and SV-waves is studied. Results indicate that (i the total scattering cross section (SCS is almost symmetric about the axis α=π/2 with respect to the location (α of the imperfect interface, (ii imperfect interfaces located at α=0 and α=π highly reduce the total SCS under a P-wave incidence and imperfect interfaces located at α=π/2 reduce the total SCS most significantly under SV-incidence, and (iii under a P-wave incidence the SCS has a high sensitivity to the bonding level of imperfect interfaces when α is small, while it becomes more sensitive to the bonding level when α is larger under SV-wave incidence.
Spectral analysis of surface waves method to assess shear wave velocity within centrifuge models
Murillo, Carol Andrea; Thorel, Luc; Caicedo, Bernardo
2009-06-01
The method of the spectral analysis of surface waves (SASW) is tested out on reduced scale centrifuge models, with a specific device, called the mini Falling Weight, developed for this purpose. Tests are performed on layered materials made of a mixture of sand and clay. The shear wave velocity VS determined within the models using the SASW is compared with the laboratory measurements carried out using the bender element test. The results show that the SASW technique applied to centrifuge testing is a relevant method to characterize VS near the surface.
Low-lying S-wave and P-wave dibaryons in a nodal structure analysis
International Nuclear Information System (INIS)
Liu Yuxin; Li Jingsheng; Bao Chengguang
2003-01-01
The inherent nodal surface structure analysis approach is proposed for six-quark clusters with u, d, and s quarks. The wave functions of the six-quark clusters are classified, and the contribution of the hidden-color channels are discussed. The quantum numbers and configurations of the wave functions of the low-lying dibaryons are obtained. The states [ΩΩ] (0,0 + ) , [ΩΩ] (0,2 - ) , [Ξ * Ω] (1/2,0 + ) , and [Σ * Σ * ] (0,4 - ) and the hidden-color channel states with the same quantum numbers are proposed to be the candidates of experimentally observable dibaryons
International Nuclear Information System (INIS)
Ross, N.; Kostylev, M.; Stamps, R. L.
2014-01-01
Standing spin wave mode frequencies and linewidths in partially disordered perpendicular magnetized arrays of sub-micron Permalloy discs are measured using broadband ferromagnetic resonance and compared to analytical results from a single, isolated disc. The measured mode structure qualitatively reproduces the structure expected from the theory. Fitted demagnetizing parameters decrease with increasing array disorder. The frequency difference between the first and second radial modes is found to be higher in the measured array systems than predicted by theory for an isolated disc. The relative frequencies between successive spin wave modes are unaffected by reduction of the long-range ordering of discs in the array. An increase in standing spin wave resonance linewidth at low applied magnetic fields is observed and grows more severe with increased array disorder.
Analysis and optimization of Love wave liquid sensors.
Jakoby, B; Vellekoop, M J
1998-01-01
Love wave sensors are highly sensitive microacoustic devices, which are well suited for liquid sensing applications thanks to the shear polarization of the wave. The sensing mechanism thereby relies on the mechanical (or acoustic) interaction of the device with the liquid. The successful utilization of Love wave devices for this purpose requires proper shielding to avoid unwanted electric interaction of the liquid with the wave and the transducers. In this work we describe the effects of this electric interaction and the proper design of a shield to prevent it. We present analysis methods, which illustrate the impact of the interaction and which help to obtain an optimized design of the proposed shield. We also present experimental results for devices that have been fabricated according to these design rules.
International Nuclear Information System (INIS)
Boaga, J; Vignoli, G; Cassiani, G
2011-01-01
Inversion is a critical step in all geophysical techniques, and is generally fraught with ill-posedness. In the case of seismic surface wave studies, the inverse problem can lead to different equivalent subsoil models and consequently to different local seismic response analyses. This can have a large impact on an earthquake engineering design. In this paper, we discuss the consequences of non-uniqueness of surface wave inversion on seismic responses, with both numerical and experimental data. Our goal is to evaluate the consequences on common seismic response analysis in the case of different impedance contrast conditions. We verify the implications of inversion uncertainty, and consequently of data information content, on realistic local site responses. A stochastic process is used to generate a set of 1D shear wave velocity profiles from several specific subsurface models. All these profiles are characterized as being equivalent, i.e. their responses, in terms of a dispersion curve, are compatible with the uncertainty in the same surface wave data. The generated 1D shear velocity models are then subjected to a conventional one-dimensional seismic ground response analysis using a realistic input motion. While recent analyses claim that the consequences of surface wave inversion uncertainties are very limited, our test points out that a relationship exists between inversion confidence and seismic responses in different subsoils. In the case of regular and relatively smooth increase of shear wave velocities with depth, as is usual in sedimentary plains, our results show that the choice of a specific model among equivalent solutions strongly influences the seismic response. On the other hand, when the shallow subsoil is characterized by a strong impedance contrast (thus revealing a characteristic soil resonance period), as is common in the presence of a shallow bedrock, equivalent solutions provide practically the same seismic amplification, especially in the
Kral, C.; Haumer, A.; Bogomolov, M.D.; Lomonova, E.
2012-01-01
This paper proposes a multi domain physical model of permanent magnet synchronous machines, considering electrical, magnetic, thermal and mechanical effects. For each component of the model, the main wave as well as lower and higher harmonic wave components of the magnetic flux and the magnetic
P-wave and surface wave survey for permafrost analysis in alpine regions
Godio, A.; Socco, L. V.; Garofalo, F.; Arato, A.; Théodule, A.
2012-04-01
In various high mountain environments the estimate of mechanical properties of slope and sediments are relevant for the link of the geo-mechanical properties with the climate change effects. Two different locations were selected to perform seismic and georadar surveying, the Tsanteleina glacier (Gran Paradiso) and the Blue Lake in Val d'Ayas in the massif of Monterosa. The analysis of the seismic and GPR lines allowed to characterize the silty soil (top layer) and underlying bedrock. We applied seismic survey in time lapse mode to check the presence of "active" layer and estimate the mechanical properties of the moraines material and their sensitivity to the permafrost changes. Mechanical properties of sediments and moraines in glacial areas are related to the grain-size, the compaction of the material subjected to the past glacial activity, the presence of frozen materials and the reactivity of the permafrost to the climate changes. The test site of Tsanteleina has been equipped with sensors to monitor the temperature of soil and air and with time domain reflectometry to estimate the soil moisture and the frozen and thawing cycle of the uppermost material. Seismic reflections from the top of the permafrost layer are difficult to identify as they are embedded in the source-generated noise. Therefore we estimate seismic velocities from the analysis of traveltime refraction tomography and the analysis of surface wave. This approach provides information on compressional and shear waves using a single acquisition layout and a hammer acts as source. This reduces the acquisition time in complex logistical condition especially in winter period. The seismic survey was performed using 48 vertical geophones with 2 m spacing. The survey has been repeated in two different periods: summer 2011 and winter 2011. Common offset reflection lines with a 200 MHz GPR system (in summer) permitted to investigate the sediments and obtain information on the subsoil layering. The processing
Partial differential equations with variable exponents variational methods and qualitative analysis
Radulescu, Vicentiu D
2015-01-01
Partial Differential Equations with Variable Exponents: Variational Methods and Qualitative Analysis provides researchers and graduate students with a thorough introduction to the theory of nonlinear partial differential equations (PDEs) with a variable exponent, particularly those of elliptic type. The book presents the most important variational methods for elliptic PDEs described by nonhomogeneous differential operators and containing one or more power-type nonlinearities with a variable exponent. The authors give a systematic treatment of the basic mathematical theory and constructive meth
Sensitivity analysis of P-waves and S-waves to gas hydrate in the Shenhu area using OBS
Xing, Lei; Liu, Xueqin; Zhang, Jin; Liu, Huaishan; Zhang, Jing; Li, Zizheng; Wang, Jianhua
2018-02-01
Compared to towed streamers, ocean-bottom seismometers (OBS) obtain both S-wave data and richer wavefield information. In this paper, the induced polarization method is used to conduct wavefield separation on OBS data obtained from the Shenhu area in the South China Sea. A comparison of the changes in P- and S-waves, and a comprehensive analysis of geological factors within the area, enable analysis and description of the occurrence of natural gas hydrate in the study area. Results show an increase in P-wave velocity when natural gas hydrate exists in the formation, whereas the S-wave velocity remains almost constant, as S-waves can only propagate through the rock skeleton. Therefore, the bottom-simulating reflection (BSR) response of the P-wave is better than that of the S-wave in the frequency analysis profile. In a wide-angle section, the refractive wave of the hydrate layer is evident when using P-wave components but identification is difficult with S-wave components. This velocity model illustrates the sensitivity of P- and S-wave components to gas hydrate. The use of this polarization method and results of analysis provide technical and theoretical support for research on hydrate deposits and other geological features in the Shenhu area.
Analysis of Bending Waves in Phononic Crystal Beams with Defects
Directory of Open Access Journals (Sweden)
Yongqiang Guo
2018-01-01
Full Text Available Existing investigations on imperfect phononic crystal beams mainly concern periodic multi-span beams carrying either one or two channel waves with random or deterministic disorder in span-length. This paper studies the two channel bending waves in phononic crystal beams consisting of many phases of materials with defects introduced as one structural segment having different cross-sectional dimensions or material parameters. The method of reverberation-ray matrix (MRRM based on the Timoshenko beam theory, which can conduct high-frequency analysis, is extended for the theoretical analysis of dispersion and transmission of bending waves. The supercell technique and the Floquet–Bloch theorem are adopted for modeling the dispersion characteristics, and the whole finite structural model is used to calculate the transmission spectra. Experimental measurements and numerical calculations are provided to validate the displacement transmission obtained by the proposed MRRM, with the effect of damping on transmission spectra being concerned. The high-frequency calculation applicability of the proposed MRRM is also confirmed by comparing the present results with the corresponding ones either using the transfer matrix method (TMM or MRRM based on Euler—Bernoulli beam theory. The influences of defect size, defect form, and unit-cell number on the transmission spectra and the band structures are discussed. The drawn conclusions may be useful for designing or evaluating the defected phononic crystal beams in bending wave control. In addition, our conclusions are especially potential for identifying the defect location through bending wave signals.
Calculation of partial derivatives of thermophysical properties of sodium for safety analysis
International Nuclear Information System (INIS)
Shan Jianqiang; Qiu Suizhang; Zhu Jizhou; Zhang Guiqin
1997-01-01
According to the characters of safety analysis of LMFBR, the partial derivatives formula of some special thermophysical properties of sodium, including single-and two-phase properties, are calculated based on the basic Maxwell equations, and on the formulae of basic thermophysical properties of sodium which were verified abroad. The present study can provide theoretical base for safety analysis of LMFBR
Pietrzak, Robert H.; Goldstein, Risë B.; Southwick, Steven M.; Grant, Bridget F.
2011-01-01
Objective This study examined associations between lifetime trauma exposures, PTSD and partial PTSD, and past-year medical conditions in a nationally representative sample of U.S. adults. Methods Face-to-face interviews were conducted with 34,653 participants in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression analyses evaluated associations of trauma exposure, PTSD and partial PTSD with respondent-reported medical diagnoses. Results After adjustment for sociodemographic characteristics and comorbid Axis I and II disorders, respondents with full PTSD were more likely than traumatized respondents without full or partial PTSD (comparison group) to report diagnoses of diabetes mellitus, noncirrhotic liver disease, angina pectoris, tachycardia, hypercholesterolemia, other heart disease, stomach ulcer, HIV seropositivity, gastritis, and arthritis (odds ratios [ORs]=1.2-2.5). Respondents with partial PTSD were more likely than the comparison group to report past-year diagnoses of stomach ulcer, angina pectoris, tachycardia, and arthritis (ORs=1.3-1.6). Men with full and partial PTSD were more likely than controls to report diagnoses of hypertension (both ORs=1.6), and both men and women with PTSD (ORs=1.8 and 1.6, respectively), and men with partial PTSD (OR=2.0) were more likely to report gastritis. Total number of lifetime traumatic event types was associated with many assessed medical conditions (ORs=1.04-1.16), reducing the magnitudes and rendering non-significant some of the associations between PTSD status and medical conditions. Conclusions Greater lifetime trauma exposure and PTSD are associated with numerous medical conditions, many of which are stress-related and chronic, in U.S. adults. Partial PTSD is associated with intermediate odds of some of these conditions. PMID:21949429
Gravitational wave detection and data analysis for pulsar timing arrays
Haasteren, Rutger van
2011-01-01
Long-term precise timing of Galactic millisecond pulsars holds great promise for measuring long-period (months-to-years) astrophysical gravitational waves. In this work we develop a Bayesian data analysis method for projects called pulsar timing arrays; projects aimed to detect these gravitational
Data synthesis and display programs for wave distribution function analysis
Storey, L. R. O.; Yeh, K. J.
1992-01-01
At the National Space Science Data Center (NSSDC) software was written to synthesize and display artificial data for use in developing the methodology of wave distribution analysis. The software comprises two separate interactive programs, one for data synthesis and the other for data display.
Analysis of Different Methods for Wave Generation and Absorption in a CFD-Based Numerical Wave Tank
Directory of Open Access Journals (Sweden)
Adria Moreno Miquel
2018-06-01
Full Text Available In this paper, the performance of different wave generation and absorption methods in computational fluid dynamics (CFD-based numerical wave tanks (NWTs is analyzed. The open-source CFD code REEF3D is used, which solves the Reynolds-averaged Navier–Stokes (RANS equations to simulate two-phase flow problems. The water surface is computed with the level set method (LSM, and turbulence is modeled with the k-ω model. The NWT includes different methods to generate and absorb waves: the relaxation method, the Dirichlet-type method and active wave absorption. A sensitivity analysis has been conducted in order to quantify and compare the differences in terms of absorption quality between these methods. A reflection analysis based on an arbitrary number of wave gauges has been adopted to conduct the study. Tests include reflection analysis of linear, second- and fifth-order Stokes waves, solitary waves, cnoidal waves and irregular waves generated in an NWT. Wave breaking over a sloping bed and wave forces on a vertical cylinder are calculated, and the influence of the reflections on the wave breaking location and the wave forces on the cylinder is investigated. In addition, a comparison with another open-source CFD code, OpenFOAM, has been carried out based on published results. Some differences in the calculated quantities depending on the wave generation and absorption method have been observed. The active wave absorption method is seen to be more efficient for long waves, whereas the relaxation method performs better for shorter waves. The relaxation method-based numerical beach generally results in lower reflected waves in the wave tank for most of the cases simulated in this study. The comparably better performance of the relaxation method comes at the cost of larger computational requirements due to the relaxation zones that have to be included in the domain. The reflections in the NWT in REEF3D are generally lower than the published results for
Guided Wave Delamination Detection and Quantification With Wavefield Data Analysis
Tian, Zhenhua; Campbell Leckey, Cara A.; Seebo, Jeffrey P.; Yu, Lingyu
2014-01-01
Unexpected damage can occur in aerospace composites due to impact events or material stress during off-nominal loading events. In particular, laminated composites are susceptible to delamination damage due to weak transverse tensile and inter-laminar shear strengths. Developments of reliable and quantitative techniques to detect delamination damage in laminated composites are imperative for safe and functional optimally-designed next-generation composite structures. In this paper, we investigate guided wave interactions with delamination damage and develop quantification algorithms by using wavefield data analysis. The trapped guided waves in the delamination region are observed from the wavefield data and further quantitatively interpreted by using different wavenumber analysis methods. The frequency-wavenumber representation of the wavefield shows that new wavenumbers are present and correlate to trapped waves in the damage region. These new wavenumbers are used to detect and quantify the delamination damage through the wavenumber analysis, which can show how the wavenumber changes as a function of wave propagation distance. The location and spatial duration of the new wavenumbers can be identified, providing a useful means not only for detecting the presence of delamination damage but also allowing for estimation of the delamination size. Our method has been applied to detect and quantify real delamination damage with complex geometry (grown using a quasi-static indentation technique). The detection and quantification results show the location, size, and shape of the delamination damage.
Directory of Open Access Journals (Sweden)
Rodrigo F Ramos
2011-12-01
Full Text Available CONTEXT: Although the high incidence of gastroesophageal reflux disease (GERD in the population, there is much controversy in this topic, especially in the surgical treatment. The decision to use of a total or partial fundoplication in the treatment of GERD is still a challenge to many surgeons because the few evidence found in the literature. OBJECTIVE: To bring more clear evidence in the comparison between total and partial fundoplication. DATA SOURCES: A systematic review of the literature and metaanalysis with randomized controlled trials accessed from MEDLINE, LILACS, Cochrane Controlled Trials Database was done. The outcomes remarked were: dysphagia, inability to belch, bloating, recurrence of acid reflux, heartburn and esophagitis. For data analysis the odds ratio was used with corresponding 95% confidence interval. Statistical heterogeneity in the results of the metaanalysis was assessed by calculating a test of heterogeneity. The software Review Manager 5 (Cochrane Collaboration was utilized for the data gathered and the statistical analysis. Sensitive analysis was applied using only trials that included follow-up over 2 years. RESULTS: Ten trials were included with 1003 patients: 502 to total fundoplication group and 501 to partial fundoplication group. The outcomes dysphagia and inability to belch had statistical significant difference (P = 0.00001 in favor of partial fundoplication. There was not statistical difference in outcomes related with treatment failure. There were no heterogeneity in the outcomes dysphagia and recurrence of the acid reflux. CONCLUSION: The partial fundoplication has lower incidence of obstructive side effects.
A phase-plane analysis of localized frictional waves
Putelat, T.; Dawes, J. H. P.; Champneys, A. R.
2017-07-01
Sliding frictional interfaces at a range of length scales are observed to generate travelling waves; these are considered relevant, for example, to both earthquake ground surface movements and the performance of mechanical brakes and dampers. We propose an explanation of the origins of these waves through the study of an idealized mechanical model: a thin elastic plate subject to uniform shear stress held in frictional contact with a rigid flat surface. We construct a nonlinear wave equation for the deformation of the plate, and couple it to a spinodal rate-and-state friction law which leads to a mathematically well-posed problem that is capable of capturing many effects not accessible in a Coulomb friction model. Our model sustains a rich variety of solutions, including periodic stick-slip wave trains, isolated slip and stick pulses, and detachment and attachment fronts. Analytical and numerical bifurcation analysis is used to show how these states are organized in a two-parameter state diagram. We discuss briefly the possible physical interpretation of each of these states, and remark also that our spinodal friction law, though more complicated than other classical rate-and-state laws, is required in order to capture the full richness of wave types.
The next wave in metabolome analysis
DEFF Research Database (Denmark)
Nielsen, Jens; Oliver, S.
2005-01-01
The metabolome of a cell represents the amplification and integration of signals from other functional genomic levels, such as the transcriptome and the proteome. Although this makes metabolomics a useful tool for the high-throughput analysis of phenotypes, the lack of a direct connection...... to the genome makes it difficult to interpret metabolomic data. Nevertheless, functional genomics has produced examples of the use of metabolomics to elucidate the phenotypes of otherwise silent mutations. Despite several successes, we believe that future metabolomic studies must focus on the accurate...... measurement of the concentrations of unambiguously identified metabolites. The research community must develop databases of metabolite concentrations in cells that are grown in several well-defined conditions if metabolomic data are to be integrated meaningfully with data from the other levels of functional...
Data analysis algorithms for gravitational-wave experiments
International Nuclear Information System (INIS)
Bonifazi, P.; Ferrari, V.; Frasca, S.; Pallottino, G.V.; Pizzella, G.
1978-01-01
The analysis of the sensitivity of a gravitational-wave antenna system shows that the role of the algorithms used for the analysis of the experimental data is comparable to that of the experimental apparatus. After a discussion of the processing performed on the input signals by the antenna and the electronic instrumentation, we derive a mathematical model of the system. This model is then used as a basis for the discussion of a number of data analysis algorithms that include also the Wiener-Kolmogoroff optimum filter; the performances of the algorithms are presented in terms of signal-to-noise ratio and sensitivity to short bursts of resonant gravitational waves. The theoretical results are in good agreement with the experimental results obtained with a small cryogenic antenna (24 kg)
The analysis of linear partial differential operators I distribution theory and Fourier analysis
Hörmander, Lars
2003-01-01
The main change in this edition is the inclusion of exercises with answers and hints. This is meant to emphasize that this volume has been written as a general course in modern analysis on a graduate student level and not only as the beginning of a specialized course in partial differen tial equations. In particular, it could also serve as an introduction to harmonic analysis. Exercises are given primarily to the sections of gen eral interest; there are none to the last two chapters. Most of the exercises are just routine problems meant to give some familiarity with standard use of the tools introduced in the text. Others are extensions of the theory presented there. As a rule rather complete though brief solutions are then given in the answers and hints. To a large extent the exercises have been taken over from courses or examinations given by Anders Melin or myself at the University of Lund. I am grateful to Anders Melin for letting me use the problems originating from him and for numerous valuable comm...
Functional analytic methods in complex analysis and applications to partial differential equations
International Nuclear Information System (INIS)
Mshimba, A.S.A.; Tutschke, W.
1990-01-01
The volume contains 24 lectures given at the Workshop on Functional Analytic Methods in Complex Analysis and Applications to Partial Differential Equations held in Trieste, Italy, between 8-19 February 1988, at the ICTP. A separate abstract was prepared for each of these lectures. Refs and figs
Logical Specification and Analysis of Fault Tolerant Systems through Partial Model Checking
Gnesi, S.; Etalle, Sandro; Mukhopadhyay, S.; Lenzini, Gabriele; Lenzini, G.; Martinelli, F.; Roychoudhury, A.
2003-01-01
This paper presents a framework for a logical characterisation of fault tolerance and its formal analysis based on partial model checking techniques. The framework requires a fault tolerant system to be modelled using a formal calculus, here the CCS process algebra. To this aim we propose a uniform
Comparative study of various normal mode analysis techniques based on partial Hessians.
Ghysels, An; Van Speybroeck, Veronique; Pauwels, Ewald; Catak, Saron; Brooks, Bernard R; Van Neck, Dimitri; Waroquier, Michel
2010-04-15
Standard normal mode analysis becomes problematic for complex molecular systems, as a result of both the high computational cost and the excessive amount of information when the full Hessian matrix is used. Several partial Hessian methods have been proposed in the literature, yielding approximate normal modes. These methods aim at reducing the computational load and/or calculating only the relevant normal modes of interest in a specific application. Each method has its own (dis)advantages and application field but guidelines for the most suitable choice are lacking. We have investigated several partial Hessian methods, including the Partial Hessian Vibrational Analysis (PHVA), the Mobile Block Hessian (MBH), and the Vibrational Subsystem Analysis (VSA). In this article, we focus on the benefits and drawbacks of these methods, in terms of the reproduction of localized modes, collective modes, and the performance in partially optimized structures. We find that the PHVA is suitable for describing localized modes, that the MBH not only reproduces localized and global modes but also serves as an analysis tool of the spectrum, and that the VSA is mostly useful for the reproduction of the low frequency spectrum. These guidelines are illustrated with the reproduction of the localized amine-stretch, the spectrum of quinine and a bis-cinchona derivative, and the low frequency modes of the LAO binding protein. 2009 Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
McLoughlin, R.F.; Ryan, M.V.; Heuston, P.M.; McCoy, C.T.; Masterson, J.B.
1992-01-01
The purpose of this study was to construct and evaluate a statistical model for the quantitative analysis of computed tomographic brain images. Data were derived from standard sections in 34 normal studies. A model representing the intercranial pure tissue and partial volume areas, with allowance for beam hardening, was developed. The average percentage error in estimation of areas, derived from phantom tests using the model, was 28.47%. We conclude that our model is not sufficiently accurate to be of clinical use, even though allowance was made for partial volume and beam hardening effects. (author)
Reliability Analysis and Calibration of Partial Safety Factors for Redundant Structures
DEFF Research Database (Denmark)
Sørensen, John Dalsgaard
1998-01-01
Redundancy is important to include in the design and analysis of structural systems. In most codes of practice redundancy is not directly taken into account. In the paper various definitions of a deterministic and reliability based redundancy measure are reviewed. It is described how reundancy can...... be included in the safety system and how partial safety factors can be calibrated. An example is presented illustrating how redundancy is taken into account in the safety system in e.g. the Danish codes. The example shows how partial safety factors can be calibrated to comply with the safety level...
Schiesser, William E
2014-01-01
Features a solid foundation of mathematical and computational tools to formulate and solve real-world PDE problems across various fields With a step-by-step approach to solving partial differential equations (PDEs), Differential Equation Analysis in Biomedical Science and Engineering: Partial Differential Equation Applications with R successfully applies computational techniques for solving real-world PDE problems that are found in a variety of fields, including chemistry, physics, biology, and physiology. The book provides readers with the necessary knowledge to reproduce and extend the com
Simulation and Analysis of Converging Shock Wave Test Problems
Energy Technology Data Exchange (ETDEWEB)
Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory
2012-06-21
Results and analysis pertaining to the simulation of the Guderley converging shock wave test problem (and associated code verification hydrodynamics test problems involving converging shock waves) in the LANL ASC radiation-hydrodynamics code xRAGE are presented. One-dimensional (1D) spherical and two-dimensional (2D) axi-symmetric geometric setups are utilized and evaluated in this study, as is an instantiation of the xRAGE adaptive mesh refinement capability. For the 2D simulations, a 'Surrogate Guderley' test problem is developed and used to obviate subtleties inherent to the true Guderley solution's initialization on a square grid, while still maintaining a high degree of fidelity to the original problem, and minimally straining the general credibility of associated analysis and conclusions.
An analysis of the nucleon spectrum from lattice partially-quenched QCD
Energy Technology Data Exchange (ETDEWEB)
Armour, W. [Swansea University, Swansea, SA2 8PP, Wales, U.K.; Allton, C. R. [Swansea University, Swansea, SA2 8PP, Wales, U.K.; Leinweber, Derek B. [Univ. of Adelaide, SA (Australia); Thomas, Anthony W. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States); Young, Ross D. [Argonne National Lab. (ANL), Argonne, IL (United States)
2010-09-01
The chiral extrapolation of the nucleon mass, Mn, is investigated using data coming from 2-flavour partially-quenched lattice simulations. The leading one-loop corrections to the nucleon mass are derived for partially-quenched QCD. A large sample of lattice results from the CP-PACS Collaboration is analysed, with explicit corrections for finite lattice spacing artifacts. The extrapolation is studied using finite range regularised chiral perturbation theory. The analysis also provides a quantitative estimate of the leading finite volume corrections. It is found that the discretisation, finite-volume and partial quenching effects can all be very well described in this framework, producing an extrapolated value of Mn in agreement with experiment. This procedure is also compared with extrapolations based on polynomial forms, where the results are less encouraging.
International Nuclear Information System (INIS)
1985-11-01
Injection of vanadium ions by the laser blow-off technique has permitted to modify at will the impurity content in TFR plasmas prior to ion-cyclotron resonance (ICR) heating experiments in the mode conversion regime. The initial rate of increase of the central deuteron temperature has thus been enhanced. By solving the wave propagation equation in the WKB approximation, it has been possible to account for the enhanced dTsub(D)(O)/dt value by wave energy deposition on resonating V 21+ ions, provided a fraction (of the order of 1O%) of these ions has been accelerated to the tens of keV range. Previous experimental ICR heating results, in conditions such that the proton cyclotron layer is outside the limiter radius, can be explained by similar resonance processes on intrinsic metal impurity ions
Directory of Open Access Journals (Sweden)
Tarikul Islam
2018-03-01
Full Text Available In this article, the analytical solutions to the space-time fractional foam drainage equation and the space-time fractional symmetric regularized long wave (SRLW equation are successfully examined by the recently established rational (G′/G-expansion method. The suggested equations are reduced into the nonlinear ordinary differential equations with the aid of the fractional complex transform. Consequently, the theories of the ordinary differential equations are implemented effectively. Three types closed form traveling wave solutions, such as hyperbolic function, trigonometric function and rational, are constructed by using the suggested method in the sense of conformable fractional derivative. The obtained solutions might be significant to analyze the depth and spacing of parallel subsurface drain and small-amplitude long wave on the surface of the water in a channel. It is observed that the performance of the rational (G′/G-expansion method is reliable and will be used to establish new general closed form solutions for any other NPDEs of fractional order.
Harmonic analysis, partial differential equations and applications in honor of Richard L. Wheeden
Franchi, Bruno; Lu, Guozhen; Perez, Carlos; Sawyer, Eric
2017-01-01
This is a collection of contributed papers by many eminent Harmonic Analysts and specialists of Partial Differential equations. The papers focus on weighted norm equalities for singular integrals, focusing wave equations, degenerate elliptic equations, Navier-Stokes flow in two dimensions and Poincare-Sobolev inequalities in the setting of metric spaces equipped with measures among others. Many topics considered in this volume stem from the interests of Richard L. Wheeden whose contributions to Potential Theory, singular integral theory and degenerate elliptic PDE theory this volume honors. Luis Caffarelli, Sagun Chanillo, Bruno Franchi, Cristian Guttierez, Xiaojun Huang, Carlos Kenig, Ermanno Lanconelli, Eric Sawyer and Alexander Volberg, are some of the many contributors to this volume. .
Calculation of Scattering Amplitude Without Partial Analysis. II; Inclusion of Exchange
Temkin, Aaron; Shertzer, J.; Fisher, Richard R. (Technical Monitor)
2002-01-01
There was a method for calculating the whole scattering amplitude, f(Omega(sub k)), directly. The idea was to calculate the complete wave function Psi numerically, and use it in an integral expression for f, which can be reduced to a 2 dimensional quadrature. The original application was for e-H scattering without exchange. There the Schrodinger reduces a 2-d partial differential equation (pde), which was solved using the finite element method (FEM). Here we extend the method to the exchange approximation. The S.E. can be reduced to a pair of coupled pde's, which are again solved by the FEM. The formal expression for f(Omega(sub k)) consists two integrals, f+/- = f(sub d) +/- f(sub e); f(sub d) is formally the same integral as the no-exchange f. We have also succeeded in reducing f(sub e) to a 2-d integral. Results will be presented at the meeting.
DEFF Research Database (Denmark)
Ibsen, Lars Bo
2008-01-01
Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many...... times smaller it remains very high. For example, whilst there is enough potential wave power off the UK to supply the electricity demands several times over, the economically recoverable resource for the UK is estimated at 25% of current demand; a lot less, but a very substantial amount nonetheless....
Kenett, Dror Y; Tumminello, Michele; Madi, Asaf; Gur-Gershgoren, Gitit; Mantegna, Rosario N; Ben-Jacob, Eshel
2010-12-20
What are the dominant stocks which drive the correlations present among stocks traded in a stock market? Can a correlation analysis provide an answer to this question? In the past, correlation based networks have been proposed as a tool to uncover the underlying backbone of the market. Correlation based networks represent the stocks and their relationships, which are then investigated using different network theory methodologies. Here we introduce a new concept to tackle the above question--the partial correlation network. Partial correlation is a measure of how the correlation between two variables, e.g., stock returns, is affected by a third variable. By using it we define a proxy of stock influence, which is then used to construct partial correlation networks. The empirical part of this study is performed on a specific financial system, namely the set of 300 highly capitalized stocks traded at the New York Stock Exchange, in the time period 2001-2003. By constructing the partial correlation network, unlike the case of standard correlation based networks, we find that stocks belonging to the financial sector and, in particular, to the investment services sub-sector, are the most influential stocks affecting the correlation profile of the system. Using a moving window analysis, we find that the strong influence of the financial stocks is conserved across time for the investigated trading period. Our findings shed a new light on the underlying mechanisms and driving forces controlling the correlation profile observed in a financial market.
Quantitative subsurface analysis using frequency modulated thermal wave imaging
Subhani, S. K.; Suresh, B.; Ghali, V. S.
2018-01-01
Quantitative depth analysis of the anomaly with an enhanced depth resolution is a challenging task towards the estimation of depth of the subsurface anomaly using thermography. Frequency modulated thermal wave imaging introduced earlier provides a complete depth scanning of the object by stimulating it with a suitable band of frequencies and further analyzing the subsequent thermal response using a suitable post processing approach to resolve subsurface details. But conventional Fourier transform based methods used for post processing unscramble the frequencies with a limited frequency resolution and contribute for a finite depth resolution. Spectral zooming provided by chirp z transform facilitates enhanced frequency resolution which can further improves the depth resolution to axially explore finest subsurface features. Quantitative depth analysis with this augmented depth resolution is proposed to provide a closest estimate to the actual depth of subsurface anomaly. This manuscript experimentally validates this enhanced depth resolution using non stationary thermal wave imaging and offers an ever first and unique solution for quantitative depth estimation in frequency modulated thermal wave imaging.
Energy Technology Data Exchange (ETDEWEB)
Andrews, Nathan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Faucett, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haskin, Troy Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Luxat, Dave [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Geiger, Garrett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Codella, Brittany [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-10-01
Following the conclusion of the first phase of the crosswalk analysis, one of the key unanswered questions was whether or not the deviations found would persist during a partially recovered accident scenario, similar to the one that occurred in TMI - 2. In particular this analysis aims to compare the impact of core degradation morphology on quenching models inherent within the two codes and the coolability of debris during partially recovered accidents. A primary motivation for this study is the development of insights into how uncertainties in core damage progression models impact the ability to assess the potential for recovery of a degraded core. These quench and core recovery models are of the most interest when there is a significant amount of core damage, but intact and degraded fuel still remain in the cor e region or the lower plenum. Accordingly this analysis presents a spectrum of partially recovered accident scenarios by varying both water injection timing and rate to highlight the impact of core degradation phenomena on recovered accident scenarios. This analysis uses the newly released MELCOR 2.2 rev. 966 5 and MAAP5, Version 5.04. These code versions, which incorporate a significant number of modifications that have been driven by analyses and forensic evidence obtained from the Fukushima - Daiichi reactor site.
Czech Academy of Sciences Publication Activity Database
Sawicki, Ignacy; Saltas, I.D.; Motta, M.; Amendola, L.; Kunz, M.
2017-01-01
Roč. 95, č. 8 (2017), s. 1-16, č. článku 083520. ISSN 2470-0010 R&D Projects: GA MŠk EF15_003/0000437 Grant - others:OP VVV - CoGraDS(XE) CZ.02.1.01/0.0/0.0/15_003/0000437 Institutional support: RVO:68378271 Keywords : modified gravity * gravitational waves * cosmology * large scale structure Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 4.568, year: 2016
Zav'yalov, A. S.
2018-04-01
A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to a quarter of the wavelength in the waveguide from a short-circuiter, and the total input impedance of the sample in the waveguide is directly measured. The equivalent circuit of the sample is found both without and with account of the hole. It is demonstrated that consideration of the edge effect makes it possible to obtain more exact values of the dielectric permittivity.
Chiral dynamics, S-wave contributions and angular analysis in D → ππl anti ν
Energy Technology Data Exchange (ETDEWEB)
Shi, Yu-Ji; Wang, Wei; Zhao, Shuai [Shanghai Jiao-Tong University, INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology, Department of Physics and Astronomy, Shanghai (China)
2017-07-15
We present a theoretical analysis of the D{sup -} → π{sup +}π{sup -}l anti ν and anti D{sup 0} → π{sup +}π{sup 0}l anti ν decays. We construct a general angular distribution which can include arbitrary partial waves of ππ. Retaining the S-wave and P-wave contributions we study the branching ratios, forward-backward asymmetries and a few other observables. The P-wave contribution is dominated by ρ{sup 0} resonance, and the S-wave contribution is analyzed using the unitarized chiral perturbation theory. The obtained branching fraction for D → ρlν, at the order 10{sup -3}, is consistent with the available experimental data. The S-wave contribution has a branching ratio at the order of 10{sup -4}, and this prediction can be tested by experiments like BESIII and LHCb. Future measurements can also be used to examine the π-π scattering phase shift. (orig.)
Tang, Kwong-Tin
2007-01-01
Pedagogical insights gained through 30 years of teaching applied mathematics led the author to write this set of student oriented books. Topics such as complex analysis, matrix theory, vector and tensor analysis, Fourier analysis, integral transforms, ordinary and partial differential equations are presented in a discursive style that is readable and easy to follow. Numerous clearly stated, completely worked out examples together with carefully selected problem sets with answers are used to enhance students' understanding and manipulative skill. The goal is to make students comfortable and confident in using advanced mathematical tools in junior, senior, and beginning graduate courses.
Analysis of boundary layer flow over a porous nonlinearly stretching sheet with partial slip at
Directory of Open Access Journals (Sweden)
Swati Mukhopadhyay
2013-12-01
Full Text Available The boundary layer flow of a viscous incompressible fluid toward a porous nonlinearly stretching sheet is considered in this analysis. Velocity slip is considered instead of no-slip condition at the boundary. Similarity transformations are used to convert the partial differential equation corresponding to the momentum equation into nonlinear ordinary differential equation. Numerical solution of this equation is obtained by shooting method. It is found that the horizontal velocity decreases with increasing slip parameter.
Use of correspondence analysis partial least squares on linear and unimodal data
DEFF Research Database (Denmark)
Frisvad, Jens Christian; Norsker, Merete
1996-01-01
Correspondence analysis partial least squares (CA-PLS) has been compared with PLS conceming classification and prediction of unimodal growth temperature data and an example using infrared (IR) spectroscopy for predicting amounts of chemicals in mixtures. CA-PLS was very effective for ordinating...... that could only be seen in two-dimensional plots, and also less effective predictions. PLS was the best method in the linear case treated, with fewer components and a better prediction than CA-PLS....
Comparative Study of Various Normal Mode Analysis Techniques Based on Partial Hessians
GHYSELS, AN; VAN SPEYBROECK, VERONIQUE; PAUWELS, EWALD; CATAK, SARON; BROOKS, BERNARD R.; VAN NECK, DIMITRI; WAROQUIER, MICHEL
2010-01-01
Standard normal mode analysis becomes problematic for complex molecular systems, as a result of both the high computational cost and the excessive amount of information when the full Hessian matrix is used. Several partial Hessian methods have been proposed in the literature, yielding approximate normal modes. These methods aim at reducing the computational load and/or calculating only the relevant normal modes of interest in a specific application. Each method has its own (dis)advantages and...
An Analysis of Fundamental Mode Surface Wave Amplitude Measurements
Schardong, L.; Ferreira, A. M.; van Heijst, H. J.; Ritsema, J.
2014-12-01
Seismic tomography is a powerful tool to decipher the Earth's interior structure at various scales. Traveltimes of seismic waves are widely used to build velocity models, whereas amplitudes are still only seldomly accounted for. This mainly results from our limited ability to separate the various physical effects responsible for observed amplitude variations, such as focussing/defocussing, scattering and source effects. We present new measurements from 50 global earthquakes of fundamental-mode Rayleigh and Love wave amplitude anomalies measured in the period range 35-275 seconds using two different schemes: (i) a standard time-domain amplitude power ratio technique; and (ii) a mode-branch stripping scheme. For minor-arc data, we observe amplitude anomalies with respect to PREM in the range of 0-4, for which the two measurement techniques show a very good overall agreement. We present here a statistical analysis and comparison of these datasets, as well as comparisons with theoretical calculations for a variety of 3-D Earth models. We assess the geographical coherency of the measurements, and investigate the impact of source, path and receiver effects on surface wave amplitudes, as well as their variations with frequency in a wider range than previously studied.
Global analysis of ICRF wave coupling on Tore Supra
International Nuclear Information System (INIS)
Goniche, M.; Bremond, S.; Colas, L.
2003-01-01
The Tore Supra tokamak is equipped with a multi-megawatt ion cyclotron range of frequency (ICRF) system for heating and current drive. The coupling of the fast wave to the plasma, characterized by the distributed coupling resistance along the radiating straps, is a crucial issue in order to launch large RF powers. Many factors can have an effect on ICRF wave coupling. Quantitative prediction from theoretical modelling requires the knowledge of the local inhomogeneous plasma density profile in front of the antenna for running sophisticated antenna codes. In this work, we have rather followed a 'global' approach, based on Tore Supra experimental results, for the parametric study of the coupling resistance. From a large data base covering seven experimental campaigns (∼2250 shots), a scaling law of the coupling resistance including the main parameters of the plasma and of the antenna configuration is established. This approach is found to be reliable for the analysis of coupling in the different scenarios: He/D 2 gas filling, gas/pellets for plasma fuelling, plasma leaning on inner wall/low field side limiter, limiter/ergodic divertor configuration, minority heating/direct electron heating. From one scenario to another, a significant variation of the coefficients of the scaling law is found. The study of these variations allows to get some insight on the main physical mechanisms which influence the ICRF wave coupling in a tokamak operation, such as the wall conditioning and recycling conditions, RF sheaths or frequency. (author)
Multi-channel Analysis of Passive Surface Waves (MAPS)
Xia, J.; Cheng, F. Mr; Xu, Z.; Wang, L.; Shen, C.; Liu, R.; Pan, Y.; Mi, B.; Hu, Y.
2017-12-01
Urbanization is an inevitable trend in modernization of human society. In the end of 2013 the Chinese Central Government launched a national urbanization plan—"Three 100 Million People", which aggressively and steadily pushes forward urbanization. Based on the plan, by 2020, approximately 100 million people from rural areas will permanently settle in towns, dwelling conditions of about 100 million people in towns and villages will be improved, and about 100 million people in the central and western China will permanently settle in towns. China's urbanization process will run at the highest speed in the urbanization history of China. Environmentally friendly, non-destructive and non-invasive geophysical assessment method has played an important role in the urbanization process in China. Because human noise and electromagnetic field due to industrial life, geophysical methods already used in urban environments (gravity, magnetics, electricity, seismic) face great challenges. But humanity activity provides an effective source of passive seismic methods. Claerbout pointed out that wavefileds that are received at one point with excitation at the other point can be reconstructed by calculating the cross-correlation of noise records at two surface points. Based on this idea (cross-correlation of two noise records) and the virtual source method, we proposed Multi-channel Analysis of Passive Surface Waves (MAPS). MAPS mainly uses traffic noise recorded with a linear receiver array. Because Multi-channel Analysis of Surface Waves can produces a shear (S) wave velocity model with high resolution in shallow part of the model, MPAS combines acquisition and processing of active source and passive source data in a same flow, which does not require to distinguish them. MAPS is also of ability of real-time quality control of noise recording that is important for near-surface applications in urban environment. The numerical and real-world examples demonstrated that MAPS can be
International Nuclear Information System (INIS)
Fernandez-Varea, J.M.; Salvat, F.; Liljequist, D.
1994-09-01
The details of a Monte Carlo code for computing the penetration and energy loss of electrons and positrons in solids are described. The code, intended for electrons and positrons with energies from ∼ 100 eV to ∼ 100 keV, is based on the simulation of individual elastic and inelastic collisions. Elastic collisions are simulated using differential cross sections computed by the relativistic partial wave method applied to a muffin-tin Dirac-Hartree-Fock-Slater potential. Inelastic collisions are simulated by means of a model based on optical and photoelectric data, which are extended to the non-zero momentum transfer region by means of somewhat different algorithms for valence electron excitations and inner-shell excitations. This report focuses on the description of detailed formulae and sampling methods. 10 refs, 3 figs, 8 tabs
πN → πN and KN → KN low energy data and partial wave analyses recent results and new directions
International Nuclear Information System (INIS)
Kelly, R.L.
1975-07-01
This review deals with πN → πN and KN → KN physics below about 3 GeV/c. An attempt is made to convey the state of the art, and to point out what appear to be promising directions for future research. The situation as of about one year ago is summarized in the 1974 Review of Particle Properties and in London conference talks so more recent developments are considered. A comprehensive survey of πN → πN data between the Δ region and 3 GeV/c is given. Problems associated with spin-rotation experiments are discussed, and the current πN → πN partial wave analyses. I = 1 and I = 0 KN → KN analyses, respectively, are considered
Weingarten, Toby N; Del Mundo, Serena B; Yeoh, Tze Yeng; Scavonetto, Federica; Leibovich, Bradley C; Sprung, Juraj
2014-10-01
The aim of this retrospective study is to test the hypothesis that the use of spinal analgesia shortens the length of hospital stay after partial nephrectomy. We reviewed all patients undergoing partial nephrectomy for malignancy through flank incision between January 1, 2008, and June 30, 2011. We excluded patients who underwent tumor thrombectomy, used sustained-release opioids, or had general anesthesia supplemented by epidural analgesia. Patients were grouped into "spinal" (intrathecal opioid injection for postoperative analgesia) versus "general anesthetic" group, and "early" discharge group (within 3 postoperative days) versus "late" group. Association between demographics, patient physical status, anesthetic techniques, and surgical complexity and hospital stay were analyzed using multivariable logistic regression analysis. Of 380 patients, 158 (41.6%) were discharged "early" and 151 (39.7%) were "spinal" cases. Both spinal and early discharge groups had better postoperative pain control and used less postoperative systemic opioids. Spinal analgesia was associated with early hospital discharge, odds ratio 1.52, (95% confidence interval 1.00-2.30), P = 0.05, but in adjusted analysis was no longer associated with early discharge, 1.16 (0.73-1.86), P = 0.52. Early discharge was associated with calendar year, with more recent years being associated with early discharge. Spinal analgesia combined with general anesthesia was associated with improved postoperative pain control during the 1(st) postoperative day, but not with shorter hospital stay following partial nephrectomy. Therefore, unaccounted practice changes that occurred during more recent times affected hospital stay.
An analysis of the nucleon spectrum from lattice partially-quenched QCD.
Energy Technology Data Exchange (ETDEWEB)
Armour, W.; Allton, C. R.; Leinweber, D. B.; Thomas, A. W.; Young, R. D.; Physics; Swansea Univ.; Univ. of Adelaide; Coll. of William and Mary
2010-09-01
The chiral extrapolation of the nucleon mass, M{sub n}, is investigated using data coming from 2-flavour partially-quenched lattice simulations. A large sample of lattice results from the CP-PACS Collaboration is analysed using the leading one-loop corrections, with explicit corrections for finite lattice spacing artifacts. The extrapolation is studied using finite-range regularised chiral perturbation theory. The analysis also provides a quantitative estimate of the leading finite volume corrections. It is found that the discretisation, finite volume and partial quenching effects can all be very well described in this framework, producing an extrapolated value of Mn in agreement with experiment. Furthermore, determinations of the low energy constants of the nucleon mass's chiral expansion are in agreement with previous methods, but with significantly reduced errors. This procedure is also compared with extrapolations based on polynomial forms, where the results are less encouraging.
An analysis of the nucleon spectrum from lattice partially-quenched QCD
Energy Technology Data Exchange (ETDEWEB)
Armour, W. [Department of Physics, Swansea University, Swansea SA2 8PP, Wales (United Kingdom); Allton, C.R., E-mail: c.allton@swan.ac.u [Department of Physics, Swansea University, Swansea SA2 8PP, Wales (United Kingdom); Leinweber, D.B. [Special Research Centre for the Subatomic Structure of Matter (CSSM), School of Chemistry and Physics, University of Adelaide, 5005 (Australia); Thomas, A.W. [Jefferson Lab, 12000 Jefferson Ave., Newport News, VA 23606 (United States); College of William and Mary, Williamsburg, VA 23187 (United States); Young, R.D. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)
2010-09-01
The chiral extrapolation of the nucleon mass, M{sub n}, is investigated using data coming from 2-flavour partially-quenched lattice simulations. A large sample of lattice results from the CP-PACS Collaboration is analysed using the leading one-loop corrections, with explicit corrections for finite lattice spacing artifacts. The extrapolation is studied using finite-range regularised chiral perturbation theory. The analysis also provides a quantitative estimate of the leading finite volume corrections. It is found that the discretisation, finite volume and partial quenching effects can all be very well described in this framework, producing an extrapolated value of M{sub n} in agreement with experiment. Furthermore, determinations of the low energy constants of the nucleon mass's chiral expansion are in agreement with previous methods, but with significantly reduced errors. This procedure is also compared with extrapolations based on polynomial forms, where the results are less encouraging.
Patterns of Failure After MammoSite Brachytherapy Partial Breast Irradiation: A Detailed Analysis
International Nuclear Information System (INIS)
Chen, Sea; Dickler, Adam; Kirk, Michael; Shah, Anand; Jokich, Peter; Solmos, Gene; Strauss, Jonathan; Dowlatshahi, Kambiz; Nguyen, Cam; Griem, Katherine
2007-01-01
Purpose: To report the results of a detailed analysis of treatment failures after MammoSite breast brachytherapy for partial breast irradiation from our single-institution experience. Methods and Materials: Between October 14, 2002 and October 23, 2006, 78 patients with early-stage breast cancer were treated with breast-conserving surgery and accelerated partial breast irradiation using the MammoSite brachytherapy applicator. We identified five treatment failures in the 70 patients with >6 months' follow-up. Pathologic data, breast imaging, and radiation treatment plans were reviewed. For in-breast failures more than 2 cm away from the original surgical bed, the doses delivered to the areas of recurrence by partial breast irradiation were calculated. Results: At a median follow-up time of 26.1 months, five treatment failures were identified. There were three in-breast failures more than 2 cm away from the original surgical bed, one failure directly adjacent to the original surgical bed, and one failure in the axilla with synchronous distant metastases. The crude failure rate was 7.1% (5 of 70), and the crude local failure rate was 5.7% (4 of 70). Estimated progression-free survival at 48 months was 89.8% (standard error 4.5%). Conclusions: Our case series of 70 patients with >6 months' follow-up and a median follow-up of 26 months is the largest single-institution report to date with detailed failure analysis associated with MammoSite brachytherapy. Our failure data emphasize the importance of patient selection when offering partial breast irradiation
Khater, Mostafa M. A.; Seadawy, Aly R.; Lu, Dianchen
2018-06-01
In this research, we study new two techniques that called the extended simple equation method and the novel (G‧/G) -expansion method. The extended simple equation method depend on the auxiliary equation (dϕ/dξ = α + λϕ + μϕ2) which has three ways for solving depends on the specific condition on the parameters as follow: When (λ = 0) this auxiliary equation reduces to Riccati equation, when (α = 0) this auxiliary equation reduces to Bernoulli equation and when (α ≠ 0, λ ≠ 0, μ ≠ 0) we the general solutions of this auxiliary equation while the novel (G‧/G) -expansion method depends also on similar auxiliary equation (G‧/G)‧ = μ + λ(G‧/G) + (v - 1)(G‧/G) 2 which depend also on the value of (λ2 - 4 (v - 1) μ) and the specific condition on the parameters as follow: When (λ = 0) this auxiliary equation reduces to Riccati equation, when (μ = 0) this auxiliary equation reduces to Bernoulli equation and when (λ2 ≠ 4 (v - 1) μ) we the general solutions of this auxiliary equation. This show how both of these auxiliary equation are special cases of Riccati equation. We apply these methods on two dimensional nonlinear Kadomtsev-Petviashvili Burgers equation in quantum plasma and three-dimensional nonlinear modified Zakharov-Kuznetsov equation of ion-acoustic waves in a magnetized plasma. We obtain the exact traveling wave solutions of these important models and under special condition on the parameters, we get solitary traveling wave solutions. All calculations in this study have been established and verified back with the aid of the Maple package program. The executed method is powerful, effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions.
Efficiency Analysis of a Wave Power Generation System by Using Multibody Dynamics
International Nuclear Information System (INIS)
Kim, Min Soo; Sohn, Jeong Hyun; Kim, Jung Hee; Sung, Yong Jun
2016-01-01
The energy absorption efficiency of a wave power generation system is calculated as the ratio of the wave power to the power of the system. Because absorption efficiency depends on the dynamic behavior of the wave power generation system, a dynamic analysis of the wave power generation system is required to estimate the energy absorption efficiency of the system. In this study, a dynamic analysis of the wave power generation system under wave loads is performed to estimate the energy absorption efficiency. RecurDyn is employed to carry out the dynamic analysis of the system, and the Morison equation is used for the wave load model. According to the results, the lower the wave height and the shorter the period, the higher is the absorption efficiency of the system
Efficiency Analysis of a Wave Power Generation System by Using Multibody Dynamics
Energy Technology Data Exchange (ETDEWEB)
Kim, Min Soo; Sohn, Jeong Hyun [Pukyong National Univ., Busan (Korea, Republic of); Kim, Jung Hee; Sung, Yong Jun [INGINE Inc., Seoul (Korea, Republic of)
2016-06-15
The energy absorption efficiency of a wave power generation system is calculated as the ratio of the wave power to the power of the system. Because absorption efficiency depends on the dynamic behavior of the wave power generation system, a dynamic analysis of the wave power generation system is required to estimate the energy absorption efficiency of the system. In this study, a dynamic analysis of the wave power generation system under wave loads is performed to estimate the energy absorption efficiency. RecurDyn is employed to carry out the dynamic analysis of the system, and the Morison equation is used for the wave load model. According to the results, the lower the wave height and the shorter the period, the higher is the absorption efficiency of the system.
Effects of six-quark bags on the 1D2 NN partial wave and the question of dibaryon resonances
International Nuclear Information System (INIS)
Grach, I.L.; Kalashnikova, Yu.S.; Narodetskij, I.M.
1986-01-01
The coupled 1 D 2 (pp)- 5 S 0 (ΔN) channels are studied in a relativized version of the quark compound bag (QCB) model. The QCB model is a semiphenomenological model that incorporates the important role that the bag dynamics plays at small distances. In this model, the short-range hadron force is given by the energy-dependent and non-local potential and contains few parameters which are defined by the wave function of the six-quark primitive. It is suggested that this force is responsible for the appearance of the S-matrix pole of the dibaryon amplitude. The QCD short-range force is shown to reproduce an energy dependence of the 1 D 2 phase shift and inelasticity in the region T >or approx. 200 MeV. At small energy the effect of the long-range meson force is essential. The values of the QCD parameters found from the fit to the data are in good agreement with theoretical predictions for the MIT bag model
Use of the MULTINEST algorithm for gravitational wave data analysis
International Nuclear Information System (INIS)
Feroz, Farhan; Hobson, Michael P; Gair, Jonathan R; Porter, Edward K
2009-01-01
We describe an application of the MULTINEST algorithm to gravitational wave data analysis. MULTINEST is a multimodal nested sampling algorithm designed to efficiently evaluate the Bayesian evidence and return posterior probability densities for likelihood surfaces containing multiple secondary modes. The algorithm employs a set of 'live' points which are updated by partitioning the set into multiple overlapping ellipsoids and sampling uniformly from within them. This set of 'live' points climbs up the likelihood surface through nested iso-likelihood contours and the evidence and posterior distributions can be recovered from the point set evolution. The algorithm is model independent in the sense that the specific problem being tackled enters only through the likelihood computation, and does not change how the 'live' point set is updated. In this paper, we consider the use of the algorithm for gravitational wave data analysis by searching a simulated LISA data set containing two non-spinning supermassive black hole binary signals. The algorithm is able to rapidly identify all the modes of the solution and recover the true parameters of the sources to high precision.
Use of the MULTINEST algorithm for gravitational wave data analysis
Energy Technology Data Exchange (ETDEWEB)
Feroz, Farhan; Hobson, Michael P [Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Gair, Jonathan R [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Porter, Edward K [APC, UMR 7164, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)
2009-11-07
We describe an application of the MULTINEST algorithm to gravitational wave data analysis. MULTINEST is a multimodal nested sampling algorithm designed to efficiently evaluate the Bayesian evidence and return posterior probability densities for likelihood surfaces containing multiple secondary modes. The algorithm employs a set of 'live' points which are updated by partitioning the set into multiple overlapping ellipsoids and sampling uniformly from within them. This set of 'live' points climbs up the likelihood surface through nested iso-likelihood contours and the evidence and posterior distributions can be recovered from the point set evolution. The algorithm is model independent in the sense that the specific problem being tackled enters only through the likelihood computation, and does not change how the 'live' point set is updated. In this paper, we consider the use of the algorithm for gravitational wave data analysis by searching a simulated LISA data set containing two non-spinning supermassive black hole binary signals. The algorithm is able to rapidly identify all the modes of the solution and recover the true parameters of the sources to high precision.
Experimental analysis of shock wave effects in copper
International Nuclear Information System (INIS)
Llorca, Fabrice; Buy, Francois; Farre, Jose
2002-01-01
This paper proposes the analysis of shock wave effects for a high purity copper. The method developed is based on the analysis of the mechanical behavior of as received and shocked materials. Shock effect is generated through plates impact tests performed in the range 9 GPa to 12 GPa on a single stage light gas gun. Therefore, as-received and impacted materials are characterized on quasi static and Split Hopkinson apparatus. The difference between measured stresses between as received and shocked materials allows to understand shock effects in the low pressure range of study. A specific modeling approach is engaged in order to give indications about the evolution of the microstructure of the materials
Qian, Xi-Yuan; Liu, Ya-Min; Jiang, Zhi-Qiang; Podobnik, Boris; Zhou, Wei-Xing; Stanley, H. Eugene
2015-06-01
When common factors strongly influence two power-law cross-correlated time series recorded in complex natural or social systems, using detrended cross-correlation analysis (DCCA) without considering these common factors will bias the results. We use detrended partial cross-correlation analysis (DPXA) to uncover the intrinsic power-law cross correlations between two simultaneously recorded time series in the presence of nonstationarity after removing the effects of other time series acting as common forces. The DPXA method is a generalization of the detrended cross-correlation analysis that takes into account partial correlation analysis. We demonstrate the method by using bivariate fractional Brownian motions contaminated with a fractional Brownian motion. We find that the DPXA is able to recover the analytical cross Hurst indices, and thus the multiscale DPXA coefficients are a viable alternative to the conventional cross-correlation coefficient. We demonstrate the advantage of the DPXA coefficients over the DCCA coefficients by analyzing contaminated bivariate fractional Brownian motions. We calculate the DPXA coefficients and use them to extract the intrinsic cross correlation between crude oil and gold futures by taking into consideration the impact of the U.S. dollar index. We develop the multifractal DPXA (MF-DPXA) method in order to generalize the DPXA method and investigate multifractal time series. We analyze multifractal binomial measures masked with strong white noises and find that the MF-DPXA method quantifies the hidden multifractal nature while the multifractal DCCA method fails.
Quasi-static analysis of wave loadings on spine-based wave energy devices
Energy Technology Data Exchange (ETDEWEB)
Lockett, F.P.; Peatfield, A.M.; West, M.J.
1980-02-01
A report is given on the Wave Energy Research Programme at Lanchester Polytechnic. Results are presented for both theoretical and experimental scale models for wave loadings on circular and rectangular spines of various lengths. The results are in good agreement over the operational wave range for the 1/50 scale model and for the more limited data on the 1/10 scale model.
Analysis of waves in the plasma guided by a periodical vane-type slow wave structure
International Nuclear Information System (INIS)
Wu, T.J.; Kou, C.S.
2005-01-01
In this study, the dispersion relation has been derived to characterize the propagation of the waves in the plasma guided by a periodical vane-type slow wave structure. The plasma is confined by a quartz plate. Results indicate that there are two different waves in this structure. One is the plasma mode that originates from the plasma surface wave propagating along the interface between the plasma and the quartz plate, and the other is the guide mode that originally travels along the vane-type slow wave structure. In contrast to its original slow wave characteristics, the guide mode becomes a fast wave in the low-frequency portion of the passband, and there exists a cut-off frequency for the guide mode. The vane-type guiding structure has been shown to limit the upper frequency of the passband of the plasma mode, compared with that of the plasma surface wave. In addition, the passband of the plasma mode increases with the plasma density while it becomes narrower for the guide mode. The influences of the parameters of the guiding structure and plasma density on the propagation of waves are also presented
Genetic analysis of partial resistance to basal stem rot (Sclerotinia sclerotiorum in sunflower
Directory of Open Access Journals (Sweden)
Amouzadeh Masoumeh
2013-01-01
Full Text Available Basal stem rot, caused by Sclerotinia sclerotiorum (Lib. de Bary, is one of the major diseases of sunflower (Helianthus annuus L. in the world. Quantitative trait loci (QTLs implicated in partial resistance to basal stem rot disease were identified using 99 recombinant inbred lines (RILs from the cross between sunflower parental lines PAC2 and RHA266. The study was undertaken in a completely randomized design with three replications under controlled conditions. The RILs and their parental lines were inoculated with a moderately aggressive isolate of S. sclerotiorum (SSKH41. Resistance to disease was evaluated by measuring the percentage of necrosis area three days after inoculation. QTLs were mapped using an updated high-density SSR and SNP linkage map. ANOVA showed significant differences among sunflower lines for resistance to basal stem rot (P≤0.05. The frequency distribution of lines for susceptibility to disease showed a continuous pattern. Composite interval mapping analysis revealed 5 QTLs for percentage of necrotic area, localized on linkage groups 1, 3, 8, 10 and 17. The sign of additive effect was positive in 5 QTLs, suggesting that the additive allele for partial resistance to basal stem rot came from the paternal line (RHA266. The phenotypic variance explained by QTLs (R2 ranged from 0.5 to 3.16%. Identified genes (HUCL02246_1, GST and POD, and SSR markers (ORS338, and SSL3 encompassing the QTLs for partial resistance to basal stem rot could be good candidates for marker assisted selection.
Izadi Najafabadi, Mohammad
2017-11-06
A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.
Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy.
Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S
2015-05-15
Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave-particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity.
Ockendon, Hilary
2016-01-01
Now in its second edition, this book continues to give readers a broad mathematical basis for modelling and understanding the wide range of wave phenomena encountered in modern applications. New and expanded material includes topics such as elastoplastic waves and waves in plasmas, as well as new exercises. Comprehensive collections of models are used to illustrate the underpinning mathematical methodologies, which include the basic ideas of the relevant partial differential equations, characteristics, ray theory, asymptotic analysis, dispersion, shock waves, and weak solutions. Although the main focus is on compressible fluid flow, the authors show how intimately gasdynamic waves are related to wave phenomena in many other areas of physical science. Special emphasis is placed on the development of physical intuition to supplement and reinforce analytical thinking. Each chapter includes a complete set of carefully prepared exercises, making this a suitable textbook for students in applied mathematics, ...
Three-dimensional finite element analysis of implant-assisted removable partial dentures.
Eom, Ju-Won; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom
2017-06-01
Whether the implant abutment in implant-assisted removable partial dentures (IARPDs) functions as a natural removable partial denture (RPD) tooth abutment is unknown. The purpose of this 3-dimensional finite element study was to analyze the biomechanical behavior of implant crown, bone, RPD, and IARPD. Finite element models of the partial maxilla, teeth, and prostheses were generated on the basis of a patient's computed tomographic data. The teeth, surveyed crowns, and RPDs were created in the model. With the generated components, four 3-dimensional finite element models of the partial maxilla were constructed: tooth-supported RPD (TB), implant-supported RPD (IB), tooth-tissue-supported RPD (TT), and implant-tissue-supported RPD (IT) models. Oblique loading of 300 N was applied on the crowns and denture teeth. The von Mises stress and displacement of the denture abutment tooth and implant system were identified. The highest von Mises stress values of both IARPDs occurred on the implants, while those of both natural tooth RPDs occurred on the frameworks of the RPDs. The highest von Mises stress of model IT was about twice that of model IB, while the value of model TT was similar to that of model TB. The maximum displacement was greater in models TB and TT than in models IB and IT. Among the 4 models, the highest maximum displacement value was observed in the model TT and the lowest value was in the model IB. Finite element analysis revealed that the stress distribution pattern of the IARPDs was different from that of the natural tooth RPDs and the stress distribution of implant-supported RPD was different from that of implant-tissue-supported RPD. When implants are used for RPD abutments, more consideration concerning the RPD design and the number or location of the implant is necessary. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Garcia, Emanuel; Klaas, Ilka Christine; Amigo Rubio, Jose Manuel
2014-01-01
Lameness is prevalent in dairy herds. It causes decreased animal welfare and leads to higher production costs. This study explored data from an automatic milking system (AMS) to model on-farm gait scoring from a commercial farm. A total of 88 cows were gait scored once per week, for 2 5-wk periods......). The reference gait scoring error was estimated in the first week of the study and was, on average, 15%. Two partial least squares discriminant analysis models were fitted to parity 1 and parity 2 groups, respectively, to assign the lameness class according to the predicted probability of being lame (score 3...
Thermodynamic Equilibria and Extrema Analysis of Attainability Regions and Partial Equilibria
Gorban, Alexander N; Kaganovich, Boris M; Keiko, Alexandre V; Shamansky, Vitaly A; Shirkalin, Igor A
2006-01-01
This book discusses mathematical models that are based on the concepts of classical equilibrium thermodynamics. They are intended for the analysis of possible results of diverse natural and production processes. Unlike the traditional models, these allow one to view the achievable set of partial equilibria with regards to constraints on kinetics, energy and mass exchange and to determine states of the studied systems of interest for the researcher. Application of the suggested models in chemical technology, energy and ecology is illustrated in the examples.
Dispersion analysis for waves propagated in fractured media
Energy Technology Data Exchange (ETDEWEB)
Lesniak, A; Niitsuma, H [Tohoku University, Sendai (Japan). Faculty of Engineering
1996-05-01
Dispersion of velocity is defined as a variation of the phase velocity with frequency. This paper describes the dispersion analysis of compressional body waves propagated in the heterogeneous fractured media. The new method proposed and discussed here permitted the evaluation of the variation in P wave arrival with frequency. For this processing method, any information about the attenuation of the medium are not required, and only an assumption of weak heterogeneity is important. It was shown that different mechanisms of dispersion can be distinguished and its value can be quantitatively estimated. Although the frequency used in this study was lower than those in most previous experiments reported in literature, the evaluated dispersion was large. It was suggested that such a large dispersion may be caused by the velocity structure of the media studied and by frequency dependent processes in a highly fractured zone. It was demonstrated that the present method can be used in the evaluation of subsurface fracture systems or characterization of any kind of heterogeneities. 10 refs., 6 figs.
Constraint likelihood analysis for a network of gravitational wave detectors
International Nuclear Information System (INIS)
Klimenko, S.; Rakhmanov, M.; Mitselmakher, G.; Mohanty, S.
2005-01-01
We propose a coherent method for detection and reconstruction of gravitational wave signals with a network of interferometric detectors. The method is derived by using the likelihood ratio functional for unknown signal waveforms. In the likelihood analysis, the global maximum of the likelihood ratio over the space of waveforms is used as the detection statistic. We identify a problem with this approach. In the case of an aligned pair of detectors, the detection statistic depends on the cross correlation between the detectors as expected, but this dependence disappears even for infinitesimally small misalignments. We solve the problem by applying constraints on the likelihood functional and obtain a new class of statistics. The resulting method can be applied to data from a network consisting of any number of detectors with arbitrary detector orientations. The method allows us reconstruction of the source coordinates and the waveforms of two polarization components of a gravitational wave. We study the performance of the method with numerical simulations and find the reconstruction of the source coordinates to be more accurate than in the standard likelihood method
IMPLODING IGNITION WAVES. I. ONE-DIMENSIONAL ANALYSIS
International Nuclear Information System (INIS)
Kushnir, Doron; Waxman, Eli; Livne, Eli
2012-01-01
We show that converging spherical and cylindrical shock waves may ignite a detonation wave in a combustible medium, provided the radius at which the shocks become strong exceeds a critical radius, R crit . An approximate analytic expression for R crit is derived for an ideal gas equation of state and a simple (power-law-Arrhenius) reaction law, and shown to reproduce the results of numerical solutions. For typical acetylene-air experiments we find R crit ∼ 100 μm (spherical) and R crit ∼ 1 mm (cylindrical). We suggest that the deflagration to detonation transition (DDT) observed in these systems may be due to converging shocks produced by the turbulent deflagration flow, which reaches sub- (but near) sonic velocities on scales >>R crit . Our suggested mechanism differs from that proposed by Zel'dovich et al., in which a fine-tuned spatial gradient in the chemical induction time is required to be maintained within the turbulent deflagration flow. Our analysis may be readily extended to more complicated equations of state and reaction laws. An order of magnitude estimate of R crit within a white dwarf at the pre-detonation conditions believed to lead to Type Ia supernova explosions is 0.1 km, suggesting that our proposed mechanism may be relevant for DDT initiation in these systems. The relevance of our proposed ignition mechanism to DDT initiation may be tested by both experiments and numerical simulations.
Lagrangian analysis of nonlinear wave-wave interactions in bounded plasmas
International Nuclear Information System (INIS)
Carr, A.R.
1979-01-01
In a weakly turbulent nonlinear wave-supporting medium, one of the important nonlinear processes which may occur is resonant three-wave interaction. Whitham's averaged Lagrangian method provides a general formulation of wave evolution laws which is easily adapted to nonlinear dispersive media. In this thesis, the strength of nonlinear interactions between three coherent, axisymmetric, low frequency, magnetohydrodynamic (Alfven) waves propagating in resonance along a cold cylindrical magnetized plasma column is calculated. Both a uniform and a parabolic density distribution have been considered. To account for a non-zero plasma temperature, pressure effects have been included. Distinctive features of the work are the use of cylindrical geometry, the presence of a finite rather than an infinite axial magnetic field, the treatment of a parabolic density distribution, and the inclusion of both ion and electron contributions in all expressions. Two astrophysical applications of the presented theory have been considered. In the first, the possibility of resonant three-wave coupling between geomagnetic micropulsations, which propagate as Alfven or magnetosonic waves along the Earth's magnetic field lines, has been investigated. The second case is the theory of energy transport through the solar chromosphere by upward propagating magnetohydrodynamic waves, which may then couple to heavily damped waves in the corona, causing the observed excess heating in that region
Ma, W; Zhang, T-F; Lu, P; Lu, S H
2014-01-01
Breast cancer is categorized into two broad groups: estrogen receptor positive (ER+) and ER negative (ER-) groups. Previous study proposed that under trastuzumab-based neoadjuvant chemotherapy, tumor initiating cell (TIC) featured ER- tumors response better than ER+ tumors. Exploration of the molecular difference of these two groups may help developing new therapeutic strategies, especially for ER- patients. With gene expression profile from the Gene Expression Omnibus (GEO) database, we performed partial least squares (PLS) based analysis, which is more sensitive than common variance/regression analysis. We acquired 512 differentially expressed genes. Four pathways were found to be enriched with differentially expressed genes, involving immune system, metabolism and genetic information processing process. Network analysis identified five hub genes with degrees higher than 10, including APP, ESR1, SMAD3, HDAC2, and PRKAA1. Our findings provide new understanding for the molecular difference between TIC featured ER- and ER+ breast tumors with the hope offer supports for therapeutic studies.
Including the influence of waves in the overall slope stability analysis of rubble mound breakwaters
Mollaert, J.; Tavallali, A.
2016-01-01
An offshore breakwater is designed for the construction of a LNG-terminal. For the slope stability analysis of the rubble mound breakwater the existing and the extreme wave climate are considered. Pore water pressure variations exist in the breakwater and its permeable foundation. A wave trough combined with the moment of maximum wave run-up results in a decrease and increase of the pore water pressure, respectively. Therefore, the wave actions have on overall effect on the slope stability of...
Analysis of multidimensional measurements of electromagnetic waves in the Earth's magnetosphere
Pechal, Radim
2011-01-01
Title: Analysis of multidimensional measurements of electromagnetic waves in the Earth's magnetosphere Author: Radim Pechal Department: Department of Surface and Plasma Science Supervisor: doc. RNDr. Lubomír Přech, Dr. Supervisor's e-mail address: Abstract: The thesis introduces into basic knowledge of waves in plasma, especially waves in the Earth's magnetosphere. There are mentioned some space projects focused on chorus waves. The second part of this thesis is a la...
Analysis of wave directional spreading using neural networks
Digital Repository Service at National Institute of Oceanography (India)
Deo, M.C.; Gondane, D.S.; SanilKumar, V.
describes how a representative spreading parameter could be arrived at from easily available wave parameters such as significant wave height and average zero-cross wave period, using the technique of neural networks. It is shown that training of the network...
Survival analysis with functional covariates for partial follow-up studies.
Fang, Hong-Bin; Wu, Tong Tong; Rapoport, Aaron P; Tan, Ming
2016-12-01
Predictive or prognostic analysis plays an increasingly important role in the era of personalized medicine to identify subsets of patients whom the treatment may benefit the most. Although various time-dependent covariate models are available, such models require that covariates be followed in the whole follow-up period. This article studies a new class of functional survival models where the covariates are only monitored in a time interval that is shorter than the whole follow-up period. This paper is motivated by the analysis of a longitudinal study on advanced myeloma patients who received stem cell transplants and T cell infusions after the transplants. The absolute lymphocyte cell counts were collected serially during hospitalization. Those patients are still followed up if they are alive after hospitalization, while their absolute lymphocyte cell counts cannot be measured after that. Another complication is that absolute lymphocyte cell counts are sparsely and irregularly measured. The conventional method using Cox model with time-varying covariates is not applicable because of the different lengths of observation periods. Analysis based on each single observation obviously underutilizes available information and, more seriously, may yield misleading results. This so-called partial follow-up study design represents increasingly common predictive modeling problem where we have serial multiple biomarkers up to a certain time point, which is shorter than the total length of follow-up. We therefore propose a solution to the partial follow-up design. The new method combines functional principal components analysis and survival analysis with selection of those functional covariates. It also has the advantage of handling sparse and irregularly measured longitudinal observations of covariates and measurement errors. Our analysis based on functional principal components reveals that it is the patterns of the trajectories of absolute lymphocyte cell counts, instead of
Flood Frequency Analysis For Partial Duration Series In Ganjiang River Basin
zhangli, Sun; xiufang, Zhu; yaozhong, Pan
2016-04-01
Accurate estimation of flood frequency is key to effective, nationwide flood damage abatement programs. The partial duration series (PDS) method is widely used in hydrologic studies because it considers all events above a certain threshold level as compared to the annual maximum series (AMS) method, which considers only the annual maximum value. However, the PDS has a drawback in that it is difficult to define the thresholds and maintain an independent and identical distribution of the partial duration time series; this drawback is discussed in this paper. The Ganjiang River is the seventh largest tributary of the Yangtze River, the longest river in China. The Ganjiang River covers a drainage area of 81,258 km2 at the Wanzhou hydrologic station as the basin outlet. In this work, 56 years of daily flow data (1954-2009) from the Wanzhou station were used to analyze flood frequency, and the Pearson-III model was employed as the hydrologic probability distribution. Generally, three tasks were accomplished: (1) the threshold of PDS by percentile rank of daily runoff was obtained; (2) trend analysis of the flow series was conducted using PDS; and (3) flood frequency analysis was conducted for partial duration flow series. The results showed a slight upward trend of the annual runoff in the Ganjiang River basin. The maximum flow with a 0.01 exceedance probability (corresponding to a 100-year flood peak under stationary conditions) was 20,000 m3/s, while that with a 0.1 exceedance probability was 15,000 m3/s. These results will serve as a guide to hydrological engineering planning, design, and management for policymakers and decision makers associated with hydrology.
DNA damage focus analysis in blood samples of minipigs reveals acute partial body irradiation.
Directory of Open Access Journals (Sweden)
Andreas Lamkowski
Full Text Available Radiation accidents frequently involve acute high dose partial body irradiation leading to victims with radiation sickness and cutaneous radiation syndrome that implements radiation-induced cell death. Cells that are not lethally hit seek to repair ionizing radiation (IR induced damage, albeit at the expense of an increased risk of mutation and tumor formation due to misrepair of IR-induced DNA double strand breaks (DSBs. The response to DNA damage includes phosphorylation of histone H2AX in the vicinity of DSBs, creating foci in the nucleus whose enumeration can serve as a radiation biodosimeter. Here, we investigated γH2AX and DNA repair foci in peripheral blood lymphocytes of Göttingen minipigs that experienced acute partial body irradiation (PBI with 49 Gy (± 6% Co-60 γ-rays of the upper lumbar region. Blood samples taken 4, 24 and 168 hours post PBI were subjected to γ-H2AX, 53BP1 and MRE11 focus enumeration. Peripheral blood lymphocytes (PBL of 49 Gy partial body irradiated minipigs were found to display 1-8 DNA damage foci/cell. These PBL values significantly deceed the high foci numbers observed in keratinocyte nuclei of the directly γ-irradiated minipig skin regions, indicating a limited resident time of PBL in the exposed tissue volume. Nonetheless, PBL samples obtained 4 h post IR in average contained 2.2% of cells displaying a pan-γH2AX signal, suggesting that these received a higher IR dose. Moreover, dispersion analysis indicated partial body irradiation for all 13 minipigs at 4 h post IR. While dose reconstruction using γH2AX DNA repair foci in lymphocytes after in vivo PBI represents a challenge, the DNA damage focus assay may serve as a rapid, first line indicator of radiation exposure. The occurrence of PBLs with pan-γH2AX staining and of cells with relatively high foci numbers that skew a Poisson distribution may be taken as indicator of acute high dose partial body irradiation, particularly when samples are available
Eigenmode analysis of compressional waves in the magnetosphere
International Nuclear Information System (INIS)
Cheng, C.Z.; Lin, C.S.
1987-04-01
A field-aligned eigenode analysis of compressional Alfven instabilities has been performed for a two component anisotropic plasma in a dipole magnetic field. The eigenmode equations are derived from the gyrokinetic equations in the long wavelength (k rho < 1) and low frequency (ω < ω/sub b/) limits, where rho is the hot particle gyroradius and ω/sub b/ is the hot particle bounce frequency. Two types of compressional instabilities are identified. One is the drift mirror mode which has an odd parity compressional magnetic component with respect to the magnetic equator. The other is the drift compressional mode with an even parity compressional magnetic component. For typical storm time plasma parameters neargeosynchronous orbit, the drift mirror mode is most unstable and the drift compressional mode is stable. The storm time compressional Pc 5 waves, observed by multiple satellites during November 14-15, 1979 [Takahashi et al., 1987], can be explained by the drift mirror instability
Thermal analysis of gyrotron traveling-wave tube collector
International Nuclear Information System (INIS)
Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong
2013-01-01
In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)
Wave Analysis for West Coast of South Myanmar
Directory of Open Access Journals (Sweden)
Xu Yanan
2015-01-01
Full Text Available The characteristic of southern parts of Myanmar is tropical monsoon climate, and this area is affected by few typhoons. The wave height is changed with season, the field measured data shows that the aver-age monthly maximum wave height is in June. The wave height, swelling from Indian Ocean and spreading to research area, is small. The research adopts SWAN model to simulate the waves that are transformed from off-shore to nearshore Myanmar based on the meteorological data from ECMWF. The simulated results were com-pared with satellite data and field measured data, it showed that the trend between the curves is unified, and the extreme value of simulation is close to the measured value. The simulation presents wave distribution around Myanmar southern sea, it shows that the wave height and wave directions are affected by terrain refraction and island trains shielding. When the wave is from WSW direction, the wave will be decreased fast caused by island shielding, and the direction turns to W direction at northern coastline. When the wave comes from SSW direction, the island shielding will be weak, the wave will be decreased slowly, and the direction will turn to SW direction at southern coastline.
Analysis of Technical Feasibility of Traveling Wave Reactor
International Nuclear Information System (INIS)
Kim, Sang Ji; Yoo, Jae Woon; Bae, In Ho
2011-01-01
The status and trend of TWR, patent status and its major technical characteristics were examined in this study. Main technical features of traveling wave reactor can be characterized as a reactor operation without refueling up to the reactor life more than 60 years and TWR utilizes depleted uranium which would be produced from the enrichment process as a byproduct. Enriched fuel is only loaded to an igniter which is required for initiation of burning wave. In this study, quantitative analysis of TWR arising from the technical features was carried out in terms of resource utilization, safety and integrity, and proliferation resistance. In parallel with the concept review of TerraPower SWR design concepts, independent analysis of SWR design by altering a design specification and operation strategy was done in this study. The fuel rod design of SWR was also investigated based on the current database of fuel irradiation and performance. The technical issues of TWR or SWR which should be prior to detailed research and development can be summarized as follows: ·Strong physical protection is required during the shuffling or in-service inspection period to improve the proliferation resistance. ·New flow control logic or device is required for distributing the assembly-wise flow to be corresponded with power swing of fuel assembly. ·High integrity cladding material need to be developed for covering the high fast neutron fluence more than three times of current limit which result from the high burnup and long fuel cycle. The metal fuel under the high burnup condition should be validated through the irradiation test
DISPELLING ILLUSIONS OF REFLECTION: A NEW ANALYSIS OF THE 2007 MAY 19 CORONAL 'WAVE' EVENT
International Nuclear Information System (INIS)
Attrill, Gemma D. R.
2010-01-01
A new analysis of the 2007 May 19 coronal wave-coronal mass ejection-dimmings event is offered employing base difference extreme-ultraviolet (EUV) images. Previous work analyzing the coronal wave associated with this event concluded strongly in favor of purely an MHD wave interpretation for the expanding bright front. This conclusion was based to a significant extent on the identification of multiple reflections of the coronal wave front. The analysis presented here shows that the previously identified 'reflections' are actually optical illusions and result from a misinterpretation of the running difference EUV data. The results of this new multiwavelength analysis indicate that two coronal wave fronts actually developed during the eruption. This new analysis has implications for our understanding of diffuse coronal waves and questions the validity of the analysis and conclusions reached in previous studies.
Kovács, Endre R; Benko, Mária
2009-03-01
Partial genome characterisation of a novel adenovirus, found recently in organ samples of multiple species of dead birds of prey, was carried out by sequence analysis of PCR-amplified DNA fragments. The virus, named as raptor adenovirus 1 (RAdV-1), has originally been detected by a nested PCR method with consensus primers targeting the adenoviral DNA polymerase gene. Phylogenetic analysis with the deduced amino acid sequence of the small PCR product has implied a new siadenovirus type present in the samples. Since virus isolation attempts remained unsuccessful, further characterisation of this putative novel siadenovirus was carried out with the use of PCR on the infected organ samples. The DNA sequence of the central genome part of RAdV-1, encompassing nine full (pTP, 52K, pIIIa, III, pVII, pX, pVI, hexon, protease) and two partial (DNA polymerase and DBP) genes and exceeding 12 kb pairs in size, was determined. Phylogenetic tree reconstructions, based on several genes, unambiguously confirmed the preliminary classification of RAdV-1 as a new species within the genus Siadenovirus. Further study of RAdV-1 is of interest since it represents a rare adenovirus genus of yet undetermined host origin.
Through-flow analysis of steam turbines operating under partial admission
International Nuclear Information System (INIS)
Delabriere, H.; Werthe, J.M.
1993-05-01
In order to produce electric energy with improved efficiency, Electricite de France has to check the performances of equipment proposed by manufacturers. In the specific field of steam turbines, one of the main tools of analysis is the quasi 3D through flow computer code CAPTUR, which enables the calculation of all the aerothermodynamic parameters in a steam turbine. The last development that has been performed on CAPTUR is the extension to a calculation of a flow within a turbine operating under partial admission. For such turbines, it is now possible to calculate an internal flow field, and determine the efficiency, in a much more accurate way than with previous methods, which consist in an arbitrary efficiency correction on an averaged 1D flow calculation. From the aerodynamic point of view, partial admission involves specific losses in the first stage, then expansion and turbulent mixing just downstream of the first stage. Losses in the first stage are of very different types: windage, pumping and expansion at the ends of an admission sector. Their values have been estimated, with help of experimental results, and then expressed as a slow down coefficient applied to the relative velocity at the blade outlet. As for the flow downstream the first stage, a computational analysis has been made with specific 2D and 3D codes. It has led to define the numerical treatment established in the CAPTUR code. Some problems had to be solved to make compatible a quasi 3D formulation, making an average in the azimutal direction and using a streamline curvature method, with an absolute 3D phenomenon. Certain limitations of the working conditions were first adopted, but a generalization is on hand. The calculation of a nuclear HP steam turbine operating under partial admission has been performed. Calculation results are in good accordance with tests results, especially as regards the expansion line along the stages. The code CAPTUR will be particularly useful for the calculation
Hvilshøj, S.; Jensen, K. H.; Barlebo, H. C.; Madsen, B.
1999-08-01
Inverse numerical modeling was applied to analyze pumping tests of partially penetrating wells carried out in three wells established in an unconfined aquifer in Vejen, Denmark, where extensive field investigations had previously been carried out, including tracer tests, mini-slug tests, and other hydraulic tests. Drawdown data from multiple piezometers located at various horizontal and vertical distances from the pumping well were included in the optimization. Horizontal and vertical hydraulic conductivities, specific storage, and specific yield were estimated, assuming that the aquifer was either a homogeneous system with vertical anisotropy or composed of two or three layers of different hydraulic properties. In two out of three cases, a more accurate interpretation was obtained for a multi-layer model defined on the basis of lithostratigraphic information obtained from geological descriptions of sediment samples, gammalogs, and flow-meter tests. Analysis of the pumping tests resulted in values for horizontal hydraulic conductivities that are in good accordance with those obtained from slug tests and mini-slug tests. Besides the horizontal hydraulic conductivity, it is possible to determine the vertical hydraulic conductivity, specific yield, and specific storage based on a pumping test of a partially penetrating well. The study demonstrates that pumping tests of partially penetrating wells can be analyzed using inverse numerical models. The model used in the study was a finite-element flow model combined with a non-linear regression model. Such a model can accommodate more geological information and complex boundary conditions, and the parameter-estimation procedure can be formalized to obtain optimum estimates of hydraulic parameters and their standard deviations.
Analysis of pumping tests: Significance of well diameter, partial penetration, and noise
Heidari, M.; Ghiassi, K.; Mehnert, E.
1999-01-01
The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezemeters located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.The nonlinear least squares method was applied to pumping and recovery aquifer test data in
Structural Loads Analysis for Wave Energy Converters: Preprint
Energy Technology Data Exchange (ETDEWEB)
van Rij, Jennifer A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-08-09
This study explores and verifies the generalized body-modes method for evaluating the structural loads on a wave energy converter (WEC). Historically, WEC design methodologies have focused primarily on accurately evaluating hydrodynamic loads, while methodologies for evaluating structural loads have yet to be fully considered and incorporated into the WEC design process. As wave energy technologies continue to advance, however, it has become increasingly evident that an accurate evaluation of the structural loads will enable an optimized structural design, as well as the potential utilization of composites and flexible materials, and hence reduce WEC costs. Although there are many computational fluid dynamics, structural analyses and fluid-structure-interaction (FSI) codes available, the application of these codes is typically too computationally intensive to be practical in the early stages of the WEC design process. The generalized body-modes method, however, is a reduced order, linearized, frequency-domain FSI approach, performed in conjunction with the linear hydrodynamic analysis, with computation times that could realistically be incorporated into the WEC design process. The objective of this study is to verify the generalized body-modes approach in comparison to high-fidelity FSI simulations to accurately predict structural deflections and stress loads in a WEC. Two verification cases are considered, a free-floating barge and a fixed-bottom column. Details for both the generalized body-modes models and FSI models are first provided. Results for each of the models are then compared and discussed. Finally, based on the verification results obtained, future plans for incorporating the generalized body-modes method into the WEC simulation tool, WEC-Sim, and the overall WEC design process are discussed.
Valbuena, M. A.; Avila, J.; Pantin, V.; Drouard, S.; Guyot, H.; Asensio, M. C.
2006-05-01
Low dimensional (LD) metallic oxides have been a subject of continuous interest in the last two decades, mainly due to the electronic instabilities that they present at low temperatures. In particular, charge density waves (CDW) instabilities associated with a strong electron-phonon interaction have been found in Molybdenum metallic oxides such as KMo 6O 17 purple bronze. We report an angle resolved photoemission (ARPES) study from room temperature (RT) to T ˜40 K well below the Peierls transition temperature for this material, with CDW transition temperature TCDW ˜120 K. We have focused on photoemission spectra along ΓM high symmetry direction as well as photoemission measurements were taken as a function of temperature at one representative kF point in the Brillouin zone in order to look for the characteristic gap opening after the phase transition. We found out a pseudogap opening and a decrease in the density of states near the Fermi energy, EF, consistent with the partial removal of the nested portions of the Fermi surface (FS) at temperature below the CDW transition. In order to elucidate possible Fermi liquid (FL) or non-Fermi liquid (NFL) behaviour we have compared the ARPES data with that one reported on quasi-1D K 0.3MoO 3 blue bronze.
International Nuclear Information System (INIS)
Valbuena, M.A.; Avila, J.; Pantin, V.; Drouard, S.; Guyot, H.; Asensio, M.C.
2006-01-01
Low dimensional (LD) metallic oxides have been a subject of continuous interest in the last two decades, mainly due to the electronic instabilities that they present at low temperatures. In particular, charge density waves (CDW) instabilities associated with a strong electron-phonon interaction have been found in Molybdenum metallic oxides such as KMo 6 O 17 purple bronze. We report an angle resolved photoemission (ARPES) study from room temperature (RT) to T ∼40 K well below the Peierls transition temperature for this material, with CDW transition temperature T CDW ∼120 K. We have focused on photoemission spectra along ΓM high symmetry direction as well as photoemission measurements were taken as a function of temperature at one representative k F point in the Brillouin zone in order to look for the characteristic gap opening after the phase transition. We found out a pseudogap opening and a decrease in the density of states near the Fermi energy, E F , consistent with the partial removal of the nested portions of the Fermi surface (FS) at temperature below the CDW transition. In order to elucidate possible Fermi liquid (FL) or non-Fermi liquid (NFL) behaviour we have compared the ARPES data with that one reported on quasi-1D K 0.3 MoO 3 blue bronze
Energy Technology Data Exchange (ETDEWEB)
Valbuena, M.A. [LURE, Centre Universitaire Paris-Sud, Bat. 209D, B.P. 34, 91898 Orsay Cedex (France); Avila, J. [Instituto de Ciencia de Materiales de Madrid, ICMM - CSIC, 28049 Madrid (Spain); Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin - B.P. 48, 91192 GIF-SUR-YVETTE Cedex (France); Pantin, V. [LURE, Centre Universitaire Paris-Sud, Bat. 209D, B.P. 34, 91898 Orsay Cedex (France); Drouard, S. [LEPES-CENES, B.P. 166x, 38042 Grenoble, Cedex 9 (France); Guyot, H. [LEPES-CENES, B.P. 166x, 38042 Grenoble, Cedex 9 (France); Asensio, M.C. [Instituto de Ciencia de Materiales de Madrid, ICMM - CSIC, 28049 Madrid (Spain) and Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin - B.P. 48, 91192 GIF-SUR-YVETTE Cedex (France)]. E-mail: asensio@synchrotron-soleil.fr
2006-05-30
Low dimensional (LD) metallic oxides have been a subject of continuous interest in the last two decades, mainly due to the electronic instabilities that they present at low temperatures. In particular, charge density waves (CDW) instabilities associated with a strong electron-phonon interaction have been found in Molybdenum metallic oxides such as KMo{sub 6}O{sub 17} purple bronze. We report an angle resolved photoemission (ARPES) study from room temperature (RT) to T {approx}40 K well below the Peierls transition temperature for this material, with CDW transition temperature T {sub CDW} {approx}120 K. We have focused on photoemission spectra along {gamma}M high symmetry direction as well as photoemission measurements were taken as a function of temperature at one representative k {sub F} point in the Brillouin zone in order to look for the characteristic gap opening after the phase transition. We found out a pseudogap opening and a decrease in the density of states near the Fermi energy, E {sub F}, consistent with the partial removal of the nested portions of the Fermi surface (FS) at temperature below the CDW transition. In order to elucidate possible Fermi liquid (FL) or non-Fermi liquid (NFL) behaviour we have compared the ARPES data with that one reported on quasi-1D K{sub 0.3}MoO{sub 3} blue bronze.
International Nuclear Information System (INIS)
Elsner, D.
2007-04-01
The reaction p(e, e'p)π 0 has been studied at Q 2 =0.2 (GeV/c) 2 in the region of W=1232 MeV. From measurements left and right of vector q cross section asymmetries ρ LT have been obtained in forward ρ LT (θ π 0 cm =20 )=(-11.68±2.36 stat ±2.36 sys ) and backward ρ LT (θ π 0 cm =160 )=(12.18±0.27 stat ±0.82 sys ) π 0 kinematics, from which R{S 1+ * M 1+ }/ vertical stroke M 1+ vertical stroke 2 and R{S 0+ * M 1+ }/ vertical stroke M 1+ vertical stroke 2 could be determined. Using linear polarised tagged photon beams of energy up to E γ ≅1.5 GeV the photon beam asymmetry Σ has been measured in the reaction p(vector γ, η)p. Based on coherent bremsstrahlung off a diamond crystal a maximum polarisation of P γ =49% has been achieved at E γ =1305 MeV. The beam asymmetry has been extracted from the azimuthal modulation of the cross section using both decay modes of the η into two photons and 3π 0 . Large asymmetries up to 80% are observed, in agreement with previous measurements where already available. There is also agreement with standard model calculations. However, the required partial waves to describe the measurements differ significantly. (orig.)
A wave parameters and directional spectrum analysis for extreme winds
Montoya Ramírez, Rubén Darío; Osorio Arias, Andres Fernando; Ortiz Royero, Juan Carlos; Ocampo-Torres, Francisco Javier
2013-01-01
In this research a comparison between two of the most popular ocean wave models, WAVEWATCH III™ and SWAN, was performed using data from hurricane Katrina in the Gulf of Mexico. The numerical simulation of sea surface directional wave spectrum and other wave parameters for several parameter- izations and its relation with the drag coefﬁcient was carried out. The simulated data were compared with in-situ NOAA buoy data. For most of the buoys, WAVEWATCH III™ presented the best statistical compar...
Lee, Won Chan; Hoffmann, Marc S; Arcona, Steve; D'Souza, Joseph; Wang, Qin; Pashos, Chris L
2005-10-01
department visit during the period after the failure of initial monotherapy compared with the OXC monotherapy cohort (odds ratio = 1.52; P < 0.05). Despite limitations, the results of retrospective analysis of claims data suggest that the care of patients with treatment-refractory partial seizure disorder is costly and may vary significantly based on the pattern of care.
Yan, Zhengbing; Kuang, Te-Hui; Yao, Yuan
2017-09-01
In recent years, multivariate statistical monitoring of batch processes has become a popular research topic, wherein multivariate fault isolation is an important step aiming at the identification of the faulty variables contributing most to the detected process abnormality. Although contribution plots have been commonly used in statistical fault isolation, such methods suffer from the smearing effect between correlated variables. In particular, in batch process monitoring, the high autocorrelations and cross-correlations that exist in variable trajectories make the smearing effect unavoidable. To address such a problem, a variable selection-based fault isolation method is proposed in this research, which transforms the fault isolation problem into a variable selection problem in partial least squares discriminant analysis and solves it by calculating a sparse partial least squares model. As different from the traditional methods, the proposed method emphasizes the relative importance of each process variable. Such information may help process engineers in conducting root-cause diagnosis. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Dual stacked partial least squares for analysis of near-infrared spectra
Energy Technology Data Exchange (ETDEWEB)
Bi, Yiming [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Xie, Qiong, E-mail: yimbi@163.com [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Zhao, Yuhui [School of Economics and Business, Northeastern University at Qinhuangdao, 066000 Qinhuangdao City (China); Li, Changwen [Food Research Institute of Tianjin Tasly Group, 300410 Tianjin (China)
2013-08-20
Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications.
Dual stacked partial least squares for analysis of near-infrared spectra
International Nuclear Information System (INIS)
Bi, Yiming; Xie, Qiong; Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie; Zhao, Yuhui; Li, Changwen
2013-01-01
Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications
Thermodynamic analysis of a coal-based polygeneration system with partial gasification
International Nuclear Information System (INIS)
Li, Yuanyuan; Zhang, Guoqiang; Yang, Yongping; Zhai, Dailong; Zhang, Kai; Xu, Gang
2014-01-01
This study proposed a polygeneration system based on coal partial gasification, in which methanol and power were generated. This proposed system, comprising chemical and power islands, was designed and its characteristics are analyzed. The commercial software Aspen Plus was used to perform the system analysis. In the case study, the energy and exergy efficiency values of the proposed polygeneration system were 51.16% and 50.58%, which are 2.34% and 2.10%, respectively, higher than that of the reference system. Energy-Utilization Diagram analysis showed that removing composition adjustment and recycling 72.7% of the unreacted gas could reduce the exergy destruction during methanol synthesis by 46.85% and that the char utilized to preheat the compressed air could reduce the exergy destruction during combustion by 10.28%. Sensitivity analysis was also performed. At the same capacity ratio, the energy and exergy efficiency values of the proposed system were 1.30%–2.48% and 1.21%–2.30% higher than that of the reference system, respectively. The range of chemical-to-power capacity ratio in the proposed system was 0.41–1.40, which was narrower than that in the reference system. But the range of 1.04–1.4 was not recommended for the disappearance of energy saving potential in methanol synthesis. - Highlights: • A novel polygeneration system based on coal partial gasification is proposed. • The efficient conversion method for methanol and power is explored. • The exergy destruction in chemical energy conversion processes is decreased. • Thermodynamic performance and system characteristics are analyzed
Pregabalin versus gabapentin in partial epilepsy: a meta-analysis of dose-response relationships
Directory of Open Access Journals (Sweden)
Thompson Sally
2010-11-01
Full Text Available Abstract Background To compare the efficacy of pregabalin and gabapentin at comparable effective dose levels in patients with refractory partial epilepsy. Methods Eight randomized placebo controlled trials investigating the efficacy of pregabalin (4 studies and gabapentin (4 studies over 12 weeks were identified with a systematic literature search. The endpoints of interest were "responder rate" (where response was defined as at least a 50% reduction from baseline in the number of seizures and "change from baseline in seizure-free days over the last 28 days (SFD". Results of all trials were analyzed using an indirect comparison approach with placebo as the common comparator. The base-case analysis used the intention-to-treat last observation carried forward method. Two sensitivity analyses were conducted among completer and responder populations. Results The base-case analysis revealed statistically significant differences in response rate in favor of pregabalin 300 mg versus gabapentin 1200 mg (odds ratio, 1.82; 95% confidence interval, 1.02, 3.25 and pregabalin 600 mg versus gabapentin 1800 mg (odds ratio, 2.52; 95% confidence interval, 1.21, 5.27. Both sensitivity analyses supported the findings of the base-case analysis, although statistical significance was not demonstrated. All dose levels of pregabalin (150 mg to 600 mg were more efficacious than corresponding dosages of gabapentin (900 mg to 2400 mg in terms of SFD over the last 28 days. Conclusion In patients with refractory partial epilepsy, pregabalin is likely to be more effective than gabapentin at comparable effective doses, based on clinical response and the number of SFD.
Reactor modeling and process analysis for partial oxidation of natural gas
Albrecht, B.A.
2004-01-01
This thesis analyses a novel process of partial oxidation of natural gas and develops a numerical tool for the partial oxidation reactor modeling. The proposed process generates syngas in an integrated plant of a partial oxidation reactor, a syngas turbine and an air separation unit. This is called
Surface acoustic wave nebulization facilitating lipid mass spectrometric analysis.
Yoon, Sung Hwan; Huang, Yue; Edgar, J Scott; Ting, Ying S; Heron, Scott R; Kao, Yuchieh; Li, Yanyan; Masselon, Christophe D; Ernst, Robert K; Goodlett, David R
2012-08-07
Surface acoustic wave nebulization (SAWN) is a novel method to transfer nonvolatile analytes directly from the aqueous phase to the gas phase for mass spectrometric analysis. The lower ion energetics of SAWN and its planar nature make it appealing for analytically challenging lipid samples. This challenge is a result of their amphipathic nature, labile nature, and tendency to form aggregates, which readily precipitate clogging capillaries used for electrospray ionization (ESI). Here, we report the use of SAWN to characterize the complex glycolipid, lipid A, which serves as the membrane anchor component of lipopolysaccharide (LPS) and has a pronounced tendency to clog nano-ESI capillaries. We also show that unlike ESI SAWN is capable of ionizing labile phospholipids without fragmentation. Lastly, we compare the ease of use of SAWN to the more conventional infusion-based ESI methods and demonstrate the ability to generate higher order tandem mass spectral data of lipid A for automated structure assignment using our previously reported hierarchical tandem mass spectrometry (HiTMS) algorithm. The ease of generating SAWN-MS(n) data combined with HiTMS interpretation offers the potential for high throughput lipid A structure analysis.
Value Added Tax and price stability in Nigeria: A partial equilibrium analysis
Directory of Open Access Journals (Sweden)
Marius Ikpe
2013-12-01
Full Text Available The economic impact of Value Added Tax (VAT that was implemented in Nigeria in 1994 has generated much debate in recent times, especially with respect to its effect on the level of aggregate prices. This study empirically examines the influence of VAT on price stability in Nigeria using partial equilibrium analysis. We introduced the VAT variable in the framework of a combination of structuralist, monetarist and fiscalist approaches to inflation modelling. The analysis was carried out by applying multiple regression analysis in static form to data for the 1994-2010 period. The results reveal that VAT exerts a strong upward pressure on price levels, most likely due to the burden of VAT on intermediate outputs. The study rules out the option of VAT exemptions for intermediate outputs as a solution, due to the difficulty in distinguishing between intermediate and final outputs. Instead, it recommends a detailed post-VAT cost-benefit analysis to assess the social desirability of VAT policy in Nigeria.
Regional frequency analysis of extreme rainfalls using partial L moments method
Zakaria, Zahrahtul Amani; Shabri, Ani
2013-07-01
An approach based on regional frequency analysis using L moments and LH moments are revisited in this study. Subsequently, an alternative regional frequency analysis using the partial L moments (PL moments) method is employed, and a new relationship for homogeneity analysis is developed. The results were then compared with those obtained using the method of L moments and LH moments of order two. The Selangor catchment, consisting of 37 sites and located on the west coast of Peninsular Malaysia, is chosen as a case study. PL moments for the generalized extreme value (GEV), generalized logistic (GLO), and generalized Pareto distributions were derived and used to develop the regional frequency analysis procedure. PL moment ratio diagram and Z test were employed in determining the best-fit distribution. Comparison between the three approaches showed that GLO and GEV distributions were identified as the suitable distributions for representing the statistical properties of extreme rainfall in Selangor. Monte Carlo simulation used for performance evaluation shows that the method of PL moments would outperform L and LH moments methods for estimation of large return period events.
Structural studies of formic acid using partial form-factor analysis
International Nuclear Information System (INIS)
Swan, G.; Dore, J.C.; Bellissent-Funel, M.C.
1993-01-01
Neutron diffraction measurements have been made of liquid formic acid using H/D isotopic substitution. Data are recorded for samples of DCOOD, HCOOD and a (H/D)COOD mixture (α D =0.36). A first-order difference method is used to determine the intra-molecular contribution through the introduction of a partial form-factor analysis technique incorporating a hydrogen-bond term. The method improves the sensitivity of the parameters defining the molecular geometry and avoids some of the ambiguities arising from terms involving spatial overlap of inter- and intra-molecular features. The possible application to other systems is briefly reviewed. (authors). 8 figs., 2 tabs., 8 refs
Stress analysis of partial sphere used for bottom shell of off-shore structure
International Nuclear Information System (INIS)
Nishimaki, Ko; Matsumoto, Kohei; Hori, Tohru; Takeshita, Haruyuki; Iwata, Setsuo
1976-01-01
In the near future, various huge off-shore structures will be constructed. Concrete shall become a leading material in the structures, owing to its versatile properties. One of the limitations of concrete is its low tensile strength. The problem of low tensile strength of concrete is dealt with in main by two different methods: by applying prestressing and by designing the structural configuration so that no tensile stresses appear. In the paper, the authors discuss the application of partially spherical shell to huge off-shore structures. Structural analysis by using the finite element method were done in order to investigate the feasibility of the structure. The results were arranged as to certain parameters to derive design charts by which the stresses of check points can be presumed. Optimum shape is also discussed. (auth.)
Fit Analysis of Different Framework Fabrication Techniques for Implant-Supported Partial Prostheses.
Spazzin, Aloísio Oro; Bacchi, Atais; Trevisani, Alexandre; Farina, Ana Paula; Dos Santos, Mateus Bertolini
2016-01-01
This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the frameworks and the abutments was evaluated with an optical microscope using the single-screw test. Data were analyzed using one-way analysis of variance and Tukey test (α = .05). The one-piece casted frameworks presented significantly higher vertical misfit values than those found for framework cemented on prepared abutments and laser welding techniques (P Laser welding and framework cemented on prepared abutments are effective techniques to improve the adaptation of three-unit implant-supported prostheses. These techniques presented similar fit.
Alfriend, K. T.
1973-01-01
A ring partially filled with a viscous fluid has been analyzed as a nutation damper for a spinning satellite. The fluid has been modelled as a rigid slug of finite length moving in a tube and resisted by a linear viscous force. It is shown that there are two distinct modes of motion, called the spin synchronous mode and the nutation synchronous mode. Time constants for each mode are obtained for both the symmetric and asymmetric satellite. The effects of a stop in the tube and an offset of the ring from the spin axis are also investigated. An analysis of test results is also given including a determination of the effect of gravity on the time constants in the two modes.
Analysis of the flamelet concept in the numerical simulation of laminar partially premixed flames
Energy Technology Data Exchange (ETDEWEB)
Consul, R.; Oliva, A.; Perez-Segarra, C.D.; Carbonell, D. [Centre Tecnologic de Transferencia de Calor (CTTC), Universitat Politecnica de Catalunya (UPC), Colom 11, E-08222, Terrassa, Barcelona (Spain); de Goey, L.P.H. [Eindhoven University of Technology, Department of Mechanical Engineering, P.O. Box 513, 5600 MB Eindhoven (Netherlands)
2008-04-15
The aim of this work is to analyze the application of flamelet models based on the mixture fraction variable and its dissipation rate to the numerical simulation of partially premixed flames. Although the main application of these models is the computation of turbulent flames, this work focuses on the performance of flamelet concept in laminar flame simulations removing, in this way, turbulence closure interactions. A well-known coflow methane/air laminar flame is selected. Five levels of premixing are taken into account from an equivalence ratio {phi}={infinity} (nonpremixed) to {phi}=2.464. Results obtained using the flamelet approaches are compared to data obtained from the detailed solution of the complete transport equations using primitive variables. Numerical simulations of a counterflow flame are also presented to support the discussion of the results. Special emphasis is given to the analysis of the scalar dissipation rate modeling. (author)
International Nuclear Information System (INIS)
Shah, Anand P.; Dickler, Adam; Kirk, Michael C.; Chen, Sea S.; Strauss, Jonathan B.; Coon, Alan B.; Turian, Julius V.; Siziopikou, Kalliopi; Dowlat, Kambiz; Griem, Katherine L.
2008-01-01
Partial breast irradiation (PBI) was designed in part to decrease overall treatment times associated with whole breast radiation therapy (WBRT). WBRT treats the entire breast and usually portions of the axilla. The goal of PBI is to treat a smaller volume of breast tissue in less time, focusing the dose around the lumpectomy cavity. The following is a case of a 64-year-old woman with early-stage breast cancer treated with PBI who failed regionally in the ipsilateral axilla. With our dosimetric analysis, we found that the entire area of this axillary failure would have likely received at least 45 Gy if WBRT had been used, enough to sterilize microscopic disease. With PBI, this area received a mean dose of only 2.8 Gy, which raises the possibility that this regional failure may have been prevented had WBRT been used instead of PBI
Xu, Yue; Wu, Yining; Deng, Shimin; Wei, Shirang
2004-02-01
The partial coal gasification air pre-heating coal-fired combined cycle (PGACC) is a cleaning coal power system, which integrates the coal gasification technology, circulating fluidized bed technology, and combined cycle technology. It has high efficiency and simple construction, and is a new selection of the cleaning coal power systems. A thermodynamic analysis of the PGACC is carried out. The effects of coal gasifying rate, pre-heating air temperature, and coal gas temperature on the performances of the power system are studied. In order to repower the power plant rated 100 MW by using the PGACC, a conceptual design is suggested. The computational results show that the PGACC is feasible for modernizing the old steam power plants and building the new cleaning power plants.
3-D fracture analysis using a partial-reduced integration scheme
International Nuclear Information System (INIS)
Leitch, B.W.
1987-01-01
This paper presents details of 3-D elastic-plastic analyses of axially orientated external surface flaw in an internally pressurized thin-walled cylinder and discusses the variation of the J-integral values around the crack tip. A partial-reduced-integration-penalty method is introduced to minimize this variation of the J-integral near the crack tip. Utilizing 3-D symmetry, an eighth segment of a tube containing an elliptically shaped external surface flaw is modelled using 20-noded isoparametric elements. The crack-tip elements are collapsed to form a 1/r stress singularity about the curved crack front. The finite element model is subjected to internal pressure and axial pressure-generated loads. The virtual crack extension method is used to determine linear elastic stress intensity factors from the J-integral results at various points around the crack front. Despite the different material constants and the thinner wall thickness in this analysis, the elastic results compare favourably with those obtained by other researchers. The nonlinear stress-strain behaviour of the tube material is modelled using an incremental theory of plasticity. Variations of the J-integral values around the curved crack front of the 3-D flaw were seen. These variations could not be resolved by neglecting the immediate crack-tip elements J-integral results in favour of the more remote contour paths or else smoothed out when all the path results are averaged. Numerical incompatabilities in the 20-noded 3-D finite elements used to model the surface flaw were found. A partial-reduced integration scheme, using a combination of full and reduced integration elements, is proposed to determine J-integral results for 3-D fracture analyses. This procedure is applied to the analysis of an external semicircular surface flaw projecting halfway into the tube wall thickness. Examples of the J-integral values, before and after the partial-reduced integration method is employed, are given around the
Wave Analysis Study for the Punta Catalina Jetty, Dominican Republic
DEFF Research Database (Denmark)
Røge, Mads Sønderstrup; Andersen, Thomas Lykke; Burcharth, Hans Falk
This report deals with a two-dimensional test study to identify the largest significant wave height, the maximum wave height and the largest crest level along the Punta Catalina jetty in the Dominican Republic. The scale used for the model tests was 1:50. Unless otherwise specified all values given...
Analysis of wave equation in electromagnetic field by Proca equation
International Nuclear Information System (INIS)
Pamungkas, Oky Rio; Soeparmi; Cari
2017-01-01
This research is aimed to analyze wave equation for the electric and magnetic field, vector and scalar potential, and continuity equation using Proca equation. Then, also analyze comparison of the solution on Maxwell and Proca equation for scalar potential and electric field, both as a function of distance and constant wave number. (paper)
Wave analysis at frictional interface: A case wise study
Srivastava, Akanksha; Chattopadhyay, Amares; Singh, Pooja; Singh, Abhishek Kumar
2018-03-01
The present article deals with the propagation of a Stoneley wave and with the reflection as well as refraction of an incident P -wave at the frictional bonded interface between an initially stressed isotropic viscoelastic semi-infinite superstratum and an initially stressed isotropic substratum as case I and case II, respectively. The complex form of the velocity equation has been derived in closed form for the propagation of a Stoneley wave in the said structure. The real and imaginary parts of the complex form of the velocity equation correspond to the phase velocity and damped velocity of the Stoneley wave. Phase and damped velocity have been analysed against the angular frequency. The expressions of the amplitude ratios of the reflected and refracted waves are deduced analytically. The variation of the amplitude ratios is examined against the angle of incidence of the P -wave. The influence of frictional boundary parameters, initial stress, viscoelastic parameters on the phase and damped velocities of the Stoneley wave and the amplitude ratios of the reflected as well as refracted P - and SV -wave have been revealed graphically through numerical results.
Multi-component joint analysis of surface waves
Czech Academy of Sciences Publication Activity Database
Dal Moro, Giancarlo; Moura, R.M.M.; Moustafa, S.S.R.
2015-01-01
Roč. 119, AUG (2015), s. 128-138 ISSN 0926-9851 Institutional support: RVO:67985891 Keywords : surface waves * surface wave dispersion * seismic data acquisition * seismic data inversion * velocity spectrum Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.355, year: 2015
Bifurcation analysis and the travelling wave solutions of the Klein
Indian Academy of Sciences (India)
In this paper, we investigate the bifurcations and dynamic behaviour of travelling wave solutions of the Klein–Gordon–Zakharov equations given in Shang et al, Comput. Math. Appl. 56, 1441 (2008). Under different parameter conditions, we obtain some exact explicit parametric representations of travelling wave solutions by ...
Physiology and analysis of the electrocardiographic T wave in mice
DEFF Research Database (Denmark)
Speerschneider, T; Thomsen, Morten Bækgaard
2013-01-01
The murine electrocardiogram (ECG) is a valuable tool in cardiac research, although the definition of the T wave has been a matter of debate for several years potentially leading to incomparable data. By this study, we seek to make a clear definition of the murine T wave. Moreover, we investigate...... the consequences of performing QT interval correction in anaesthetized mice....
Analysis and design of efficient planar leaky-wave antennas
Ettore, M.
2008-01-01
This thesis deals with the effective design of planar leaky-wave antennas. The work describes a methodology based on the polar expansion of Green's function representations to address very different geometrical configurations which might appear to have little in common. In fact leaky waves with
Modal analysis of wave propagation in dispersive media
Abdelrahman, M. Ismail; Gralak, B.
2018-01-01
Surveys on wave propagation in dispersive media have been limited since the pioneering work of Sommerfeld [Ann. Phys. 349, 177 (1914), 10.1002/andp.19143491002] by the presence of branches in the integral expression of the wave function. In this article a method is proposed to eliminate these critical branches and hence to establish a modal expansion of the time-dependent wave function. The different components of the transient waves are physically interpreted as the contributions of distinct sets of modes and characterized accordingly. Then, the modal expansion is used to derive a modified analytical expression of the Sommerfeld precursor improving significantly the description of the amplitude and the oscillating period up to the arrival of the Brillouin precursor. The proposed method and results apply to all waves governed by the Helmholtz equations.
Integrated analysis of energy transfers in elastic-wave turbulence.
Yokoyama, Naoto; Takaoka, Masanori
2017-08-01
In elastic-wave turbulence, strong turbulence appears in small wave numbers while weak turbulence does in large wave numbers. Energy transfers in the coexistence of these turbulent states are numerically investigated in both the Fourier space and the real space. An analytical expression of a detailed energy balance reveals from which mode to which mode energy is transferred in the triad interaction. Stretching energy excited by external force is transferred nonlocally and intermittently to large wave numbers as the kinetic energy in the strong turbulence. In the weak turbulence, the resonant interactions according to the weak turbulence theory produce cascading net energy transfer to large wave numbers. Because the system's nonlinearity shows strong temporal intermittency, the energy transfers are investigated at active and moderate phases separately. The nonlocal interactions in the Fourier space are characterized by the intermittent bundles of fibrous structures in the real space.
Transient space-time surface waves characterization using Gabor analysis
Energy Technology Data Exchange (ETDEWEB)
Martinez, L; Wilkie-Chancellier, N; Caplain, E [Universite de Cergy Pontoise, ENS Cachan, UMR CNRS 8029, Laboratoire Systemes et Applications des Techniques de l' Information et de l' Energie (SATIE), 5 mail Gay-Lussac, F 9500 Cergy-Pontoise (France); Glorieux, C; Sarens, B, E-mail: nicolas.wilkie-chancellier@u-cergy.f [Katholieke Universiteit Leuven, Laboratorium voor Akoestiek en Thermische Fysica (LATF), Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2009-11-01
Laser ultrasonics allow the observation of transient surface waves along their propagation media and their interaction with encountered objects like cracks, holes, borders. In order to characterize and localize these transient aspects in the Space-Time-Wave number-Frequency domains, the 1D, 2D and 3D Gabor transforms are presented. The Gabor transform enables the identification of several properties of the local wavefronts such as their shape, wavelength, frequency, attenuation, group velocity and the full conversion sequence along propagation. The ability of local properties identification by Gabor transform is illustrated by two experimental studies: Lamb waves generated by an annular source on a circular quartz and Lamb wave interaction with a fluid droplet. In both cases, results obtained with Gabor transform enable ones to identify the observed local waves.
Hayashi, Shuji; Yamada, Hirotsugu; Bando, Mika; Saijo, Yoshihito; Nishio, Susumu; Hirata, Yukina; Klein, Allan L; Sata, Masataka
2015-08-01
Left atrial (LA) strain analysis using speckle tracking echocardiography is useful for assessing LA function. However, there is no established procedure for this method. Most investigators have determined the electrocardiographic R-wave peak as the starting point for LA strain analysis. To test our hypothesis that P-wave onset should be used as the starting point, we measured LA strain using 2 different starting points and compared the strain values with the corresponding LA volume indices obtained by three-dimensional (3D) echocardiography. We enrolled 78 subjects (61 ± 17 years, 25 males) with and without various cardiac diseases in this study and assessed global longitudinal LA strain by two-dimensional speckle tracking strain echocardiography using EchoPac software. We used either R-wave peak or P-wave onset as the starting point for determining LA strains during the reservoir (Rres, Pres), conduit (Rcon, Pcon), and booster pump (Rpump, Ppump) phases. We determined the maximum, minimum, and preatrial contraction LA volumes, and calculated the LA total, passive, and active emptying fractions using 3D echocardiography. The correlation between Pres and LA total emptying fraction was better than the correlation between Rres and LA total emptying fraction (r = 0.458 vs. 0.308, P = 0.026). Pcon and Ppump exhibited better correlation with the corresponding 3D echocardiographic parameters than Rcon (r = 0.560 vs. 0.479, P = 0.133) and Rpump (r = 0.577 vs. 0.345, P = 0.003), respectively. LA strain in any phase should be analyzed using P-wave onset as the starting point rather than R-wave peak. © 2014, Wiley Periodicals, Inc.
Nonlinear Modeling and Analysis of Pressure Wave inside CEUP Fuel Pipeline
Directory of Open Access Journals (Sweden)
Qaisar Hayat
2014-01-01
Full Text Available Operating conditions dependent large pressure variations are one of the working characteristics of combination electronic unit pump (CEUP fuel injection system for diesel engines. We propose a precise and accurate nonlinear numerical model of pressure inside HP fuel pipeline of CEUP using wave equation (WE including both viscous and frequency dependent frictions. We have proved that developed hyperbolic approximation gives more realistic description of pressure wave as compared to classical viscous damped wave equation. Frictional effects of various frequencies on pressure wave have been averaged out across valid frequencies to represent the combined effect of all frequencies on pressure wave. Dynamic variations of key fuel properties including density, acoustic wave speed, and bulk modulus with varying pressures have also been incorporated. Based on developed model we present analysis on effect of fuel pipeline length on pressure wave propagation and variation of key fuel properties with both conventional diesel and alternate fuel rapeseed methyl ester (RME for CEUP pipeline.
Diffusing wave spectroscopy applied to material analysis and process control
International Nuclear Information System (INIS)
Lloyd, Christopher James
1997-01-01
Diffusing Wave Spectroscopy (DWS) was studied as a method of laboratory analysis of sub-micron particles, and developed as a prospective in-line, industrial, process control sensor, capable of near real-time feedback. No sample pre-treatment was required and measurement was via a non-invasive, flexible, dip in probe. DWS relies on the concept of the diffusive migration of light, as opposed to the ballistic scatter model used in conventional dynamic light scattering. The specific requirements of the optoelectronic hardware, data analysis methods and light scattering model were studied experimentally and, where practical, theoretically resulting in a novel technique of analysis of particle suspensions and emulsions of volume fractions between 0.01 and 0.4. Operation at high concentrations made the technique oblivious to dust and contamination. A pure homodyne (autodyne) experimental arrangement described was resilient to environmental disturbances, unlike many other systems which utilise optical fibres or heterodyne operation. Pilot and subsequent prototype development led to a highly accurate method of size ranking, suitable for analysis of a wide range of suspensions and emulsions. The technique was shown to operate on real industrial samples with statistical variance as low as 0.3% with minimal software processing. Whilst the application studied was the analysis of TiO 2 suspensions, a diverse range of materials including polystyrene beads, cell pastes and industrial cutting fluid emulsions were tested. Results suggest that, whilst all sizing should be comparative to suitable standards, concentration effects may be minimised and even completely modelled-out in many applications. Adhesion to the optical probe was initially a significant problem but was minimised after the evaluation and use of suitable non stick coating materials. Unexpected behaviour in the correlation in the region of short decay times led to consideration of the effects of rotational diffusion
Partial Safety Factors for Rubble Mound Breakwaters
DEFF Research Database (Denmark)
Sørensen, John Dalsgaard; Burcharth, H. F.; Christiani, E.
1995-01-01
On the basis of the failure modes formulated in the various subtasks calibration of partial safety factors are described in this paper. The partial safety factors can be used to design breakwaters under quite different design conditions, namely probabilities of failure from 0.01 to 0.4, design...... lifetimes from 20 to 100 years and different qualities of wave data. A code of practice where safety is taken into account using partial safety factors is called a level I code. The partial safety factors are calibrated using First Order Reliability Methods (FORM, see Madsen et al. [1]) where...... in section 3. First Order Reliability Methods are described in section 4, and in section 5 it is shown how partial safety factors can be introduced and calibrated. The format of a code for design and analysis of rubble mound breakwaters is discussed in section 6. The mathematical formulation of the limit...
Analysis of Wave Reflection from Wave Energy Converters Installed as Breakwaters in Harbour
DEFF Research Database (Denmark)
Zanuttigh, B.; Margheritini, Lucia; Gambles, L.
2009-01-01
loads on the structure, i.e. better survivability. Nevertheless these devices must comply with the requirements of harbour protection structures and thus cope with problems due to reflection of incoming waves, i.e. dangerous sea states close to harbors entrances and intensified sediment scour, which can...
International Nuclear Information System (INIS)
Lue Kunhan; Lin Hsinhon; Chuang Kehshih; Kao Chihhao, K.; Hsieh Hungjen; Liu Shuhsin
2014-01-01
In positron emission tomography (PET) of the dopaminergic system, quantitative measurements of nigrostriatal dopamine function are useful for differential diagnosis. A subregional analysis of striatal uptake enables the diagnostic performance to be more powerful. However, the partial volume effect (PVE) induces an underestimation of the true radioactivity concentration in small structures. This work proposes a simple algorithm for subregional analysis of striatal uptake with partial volume correction (PVC) in dopaminergic PET imaging. The PVC algorithm analyzes the separate striatal subregions and takes into account the PVE based on the recovery coefficient (RC). The RC is defined as the ratio of the PVE-uncorrected to PVE-corrected radioactivity concentration, and is derived from a combination of the traditional volume of interest (VOI) analysis and the large VOI technique. The clinical studies, comprising 11 patients with Parkinson's disease (PD) and 6 healthy subjects, were used to assess the impact of PVC on the quantitative measurements. Simulations on a numerical phantom that mimicked realistic healthy and neurodegenerative situations were used to evaluate the performance of the proposed PVC algorithm. In both the clinical and the simulation studies, the striatal-to-occipital ratio (SOR) values for the entire striatum and its subregions were calculated with and without PVC. In the clinical studies, the SOR values in each structure (caudate, anterior putamen, posterior putamen, putamen, and striatum) were significantly higher by using PVC in contrast to those without. Among the PD patients, the SOR values in each structure and quantitative disease severity ratings were shown to be significantly related only when PVC was used. For the simulation studies, the average absolute percentage error of the SOR estimates before and after PVC were 22.74% and 1.54% in the healthy situation, respectively; those in the neurodegenerative situation were 20.69% and 2
On the resolution of ECG acquisition systems for the reliable analysis of the P-wave
International Nuclear Information System (INIS)
Censi, Federica; Calcagnini, Giovanni; Mattei, Eugenio; Triventi, Michele; Bartolini, Pietro; Corazza, Ivan; Boriani, Giuseppe
2012-01-01
The analysis of the P-wave on surface ECG is widely used to assess the risk of atrial arrhythmias. In order to provide reliable results, the automatic analysis of the P-wave must be precise and reliable and must take into account technical aspects, one of those being the resolution of the acquisition system. The aim of this note is to investigate the effects of the amplitude resolution of ECG acquisition systems on the P-wave analysis. Starting from ECG recorded by an acquisition system with a less significant bit (LSB) of 31 nV (24 bit on an input range of 524 mVpp), we reproduced an ECG signal as acquired by systems with lower resolution (16, 15, 14, 13 and 12 bit). We found that, when the LSB is of the order of 128 µV (12 bit), a single P-wave is not recognizable on ECG. However, when averaging is applied, a P-wave template can be extracted, apparently suitable for the P-wave analysis. Results obtained in terms of P-wave duration and morphology revealed that the analysis of ECG at lowest resolutions (from 12 to 14 bit, LSB higher than 30 µV) could lead to misleading results. However, the resolution used nowadays in modern electrocardiographs (15 and 16 bit, LSB <10 µV) is sufficient for the reliable analysis of the P-wave. (note)
STATISTICAL ANALYSIS OF ACOUSTIC WAVE PARAMETERS NEAR SOLAR ACTIVE REGIONS
International Nuclear Information System (INIS)
Rabello-Soares, M. Cristina; Bogart, Richard S.; Scherrer, Philip H.
2016-01-01
In order to quantify the influence of magnetic fields on acoustic mode parameters and flows in and around active regions, we analyze the differences in the parameters in magnetically quiet regions nearby an active region (which we call “nearby regions”), compared with those of quiet regions at the same disk locations for which there are no neighboring active regions. We also compare the mode parameters in active regions with those in comparably located quiet regions. Our analysis is based on ring-diagram analysis of all active regions observed by the Helioseismic and Magnetic Imager (HMI) during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the active regions, for which it is about 5.1 mHz. This amplitude enhacement (the “acoustic halo effect”) is as large as that observed in the active regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes from a deficit to an excess at around 4.2 mHz, but averages to zero over all modes. The frequency difference in nearby regions increases with increasing frequency until a point at which the frequency shifts turn over sharply, as in active regions. However, this turnover occurs around 4.9 mHz, which is significantly below the acoustic cutoff frequency. Inverting the horizontal flow parameters in the direction of the neigboring active regions, we find flows that are consistent with a model of the thermal energy flow being blocked directly below the active region.
Directory of Open Access Journals (Sweden)
Renata Dornelles Morgental
2012-04-01
Full Text Available OBJECTIVE: The presence of periapical radiolucency has been used as a criterion for endodontic treatment failure. However, in addition to the inherent limitations of radiographic examinations, radiographic interpretations are extremely subjective. Thus, this study investigated the effect of partial analysis of root filling quality and periapical status on retreatment decisions by general dentists. MATERIAL AND METHODS: Twelve digitalized periapical radiographs were analyzed by 10 observers. The study was conducted at three time points at 1-week intervals. Radiographs edited with the Adobe Photoshop CS4 software were analyzed at three time points: first, only root filling quality was analyzed; second, only the periapical areas of the teeth under study were visualized; finally, observers analyzed the unedited radiographic image. Spearman ’s coefficient was used to analyze the correlations between the scores assigned when the periapical area was not visible and when the unedited radiograph was analyzed, as well as between the scores assigned when root fillings where not visible and when the unedited radiograph was analyzed. Sensitivity, specificity, positive and negative predictive values between partial images and unedited radiographs were also used to analyze retreatment decisions. The level of significance was set at 5%. RESULTS: The visualization of the root filling on the unedited radiograph affected the interpretation of the periapical status and the technical quality of the fillings has a greater influence on the general dentist’s decision to prescribe endodontic retreatment than the periapical condition. CONCLUSION: In order to make endodontic diagnosis, radiographic interpretation process should not only emphasize technical aspects, but also consider biological factors.
Numerical analysis of quasiperiodic perturbations for the Alfven wave
International Nuclear Information System (INIS)
Yamakoshi, Y.; Muto, K.; Yoshida, Z.
1994-01-01
The Alfven wave may have a localized eigenfunction when it propagates on a chaotic magnetic field. The Arnold-Beltrami-Childress (ABC) flow is a paradigm of chaotic stream lines and is a simple exact solution to the three-dimensional force-free plasma equilibrium equations. The three-dimensional structure of the magnetic field is represented by sinusoidal quasiperiodic modulation. The short wavelength Alfven wave equation for the ABC-flow magnetic field has a quasiperiodic potential term, which induces interference among ''Bragg-reflected'' waves with irregular phases. Then the eigenfunction decays at long distance and a point spectrum occurs. Two different types of short wavelength modes have numerically analyzed to demonstrate the existence of localized Alfven wave eigenmodes
Duning, Thomas; Kellinghaus, Christoph; Mohammadi, Siawoosh; Schiffbauer, Hagen; Keller, Simon; Ringelstein, E Bernd; Knecht, Stefan; Deppe, Michael
2010-02-01
Conventional structural MRI fails to identify a cerebral lesion in 25% of patients with cryptogenic partial epilepsy (CPE). Diffusion tensor imaging is an MRI technique sensitive to microstructural abnormalities of cerebral white matter (WM) by quantification of fractional anisotropy (FA). The objectives of the present study were to identify focal FA abnormalities in patients with CPE who were deemed MRI negative during routine presurgical evaluation. Diffusion tensor imaging at 3 T was performed in 12 patients with CPE and normal conventional MRI and in 67 age matched healthy volunteers. WM integrity was compared between groups on the basis of automated voxel-wise statistics of FA maps using an analysis of covariance. Volumetric measurements from high resolution T1-weighted images were also performed. Significant FA reductions in WM regions encompassing diffuse areas of the brain were observed when all patients as a group were compared with controls. On an individual basis, voxel based analyses revealed widespread symmetrical FA reduction in CPE patients. Furthermore, asymmetrical temporal lobe FA reduction was consistently ipsilateral to the electroclinical focus. No significant correlations were found between FA alterations and clinical data. There were no differences in brain volumes of CPE patients compared with controls. Despite normal conventional MRI, WM integrity abnormalities in CPE patients extend far beyond the epileptogenic zone. Given that unilateral temporal lobe FA abnormalities were consistently observed ipsilateral to the seizure focus, analysis of temporal FA may provide an informative in vivo investigation into the localisation of the epileptogenic zone in MRI negative patients.
Directory of Open Access Journals (Sweden)
M.O.Baba Sheikh
2017-09-01
Full Text Available Canine parvovirus (CPV remains the most significant viral cause of haemorrhagic enteritis and bloody diarrhoea in puppies over the age of 12 weeks. The objective of the present study was to detect and genotype CPV-2 by polymerase chain reaction (PCR and to perform phylogenetic analysis using partial VP2 gene sequences. We analysed eight faecal samples of unvaccinated dogs with signs of vomiting and bloody diarrhoea during the period from December 2013 to May 2014 in different locations in Sulaimani, Kurdistan, Iraq. After PCR detection, we found that all viral sequences in our study were CPV-2b variants, which differed genetically by 0.8% to 3.6% from five commercially available vaccines. Alignment between eight nucleotides of field virus sequences showed 95% to 99.5% similarity. The phylogenetic analysis for the 8 field sequences formed two distinct clusters with two sequences belonging to strains from China and Thailand and the other six – with a strain from Egypt. Molecular characterisation and CPV typing are crucial in epidemiological studies for future prevention and control of the disease.
Pretreatment of wastewater: Optimal coagulant selection using Partial Order Scaling Analysis (POSA)
International Nuclear Information System (INIS)
Tzfati, Eran; Sein, Maya; Rubinov, Angelika; Raveh, Adi; Bick, Amos
2011-01-01
Jar-test is a well-known tool for chemical selection for physical-chemical wastewater treatment. Jar test results show the treatment efficiency in terms of suspended matter and organic matter removal. However, in spite of having all these results, coagulant selection is not an easy task because one coagulant can remove efficiently the suspended solids but at the same time increase the conductivity. This makes the final selection of coagulants very dependent on the relative importance assigned to each measured parameter. In this paper, the use of Partial Order Scaling Analysis (POSA) and multi-criteria decision analysis is proposed to help the selection of the coagulant and its concentration in a sequencing batch reactor (SBR). Therefore, starting from the parameters fixed by the jar-test results, these techniques will allow to weight these parameters, according to the judgments of wastewater experts, and to establish priorities among coagulants. An evaluation of two commonly used coagulation/flocculation aids (Alum and Ferric Chloride) was conducted and based on jar tests and POSA model, Ferric Chloride (100 ppm) was the best choice. The results obtained show that POSA and multi-criteria techniques are useful tools to select the optimal chemicals for the physical-technical treatment.
Yang, J-J; Yoon, U; Yun, H J; Im, K; Choi, Y Y; Lee, K H; Park, H; Hough, M G; Lee, J-M
2013-08-29
A number of imaging studies have reported neuroanatomical correlates of human intelligence with various morphological characteristics of the cerebral cortex. However, it is not yet clear whether these morphological properties of the cerebral cortex account for human intelligence. We assumed that the complex structure of the cerebral cortex could be explained effectively considering cortical thickness, surface area, sulcal depth and absolute mean curvature together. In 78 young healthy adults (age range: 17-27, male/female: 39/39), we used the full-scale intelligence quotient (FSIQ) and the cortical measurements calculated in native space from each subject to determine how much combining various cortical measures explained human intelligence. Since each cortical measure is thought to be not independent but highly inter-related, we applied partial least square (PLS) regression, which is one of the most promising multivariate analysis approaches, to overcome multicollinearity among cortical measures. Our results showed that 30% of FSIQ was explained by the first latent variable extracted from PLS regression analysis. Although it is difficult to relate the first derived latent variable with specific anatomy, we found that cortical thickness measures had a substantial impact on the PLS model supporting the most significant factor accounting for FSIQ. Our results presented here strongly suggest that the new predictor combining different morphometric properties of complex cortical structure is well suited for predicting human intelligence. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.
Wavelet analysis of interfacial waves in cocurrent two-phase flow in horizontal duct
International Nuclear Information System (INIS)
Kondo, Masaya; Kukita, Yutaka
1996-07-01
Wavelet analysis was applied to spatially-growing interfacial waves in a cocurrent gas/liquid two-phase flow. The wave growth plays a key role in the transition from stratified-wavy to slug flow, which is an important phenomena in many engineering applications. Of particular interest to the present study was the quick growth or decay of particular waves which were observed in experiments together with the general growth of waves with distance in the flow direction. Among the several wavelet functions tested in the present study, the Morlet wavelet and the Gabor function were found to have spectral and spatial resolutions suitable to the analysis of interfacial wave data taken by the authors. The analysis revealed that 1) the spectral components composing the interfacial waves are propagating at different phase velocities which agree to the theoretical velocities of deep-water waves, 2) the group velocity of the waves also agrees to the deep-water theory, and 3) the quick growth and decay of particular waves occur as a result of the superposition of spectral components with different phase velocities. (author)
[MEG]PLS: A pipeline for MEG data analysis and partial least squares statistics.
Cheung, Michael J; Kovačević, Natasa; Fatima, Zainab; Mišić, Bratislav; McIntosh, Anthony R
2016-01-01
The emphasis of modern neurobiological theories has recently shifted from the independent function of brain areas to their interactions in the context of whole-brain networks. As a result, neuroimaging methods and analyses have also increasingly focused on network discovery. Magnetoencephalography (MEG) is a neuroimaging modality that captures neural activity with a high degree of temporal specificity, providing detailed, time varying maps of neural activity. Partial least squares (PLS) analysis is a multivariate framework that can be used to isolate distributed spatiotemporal patterns of neural activity that differentiate groups or cognitive tasks, to relate neural activity to behavior, and to capture large-scale network interactions. Here we introduce [MEG]PLS, a MATLAB-based platform that streamlines MEG data preprocessing, source reconstruction and PLS analysis in a single unified framework. [MEG]PLS facilitates MRI preprocessing, including segmentation and coregistration, MEG preprocessing, including filtering, epoching, and artifact correction, MEG sensor analysis, in both time and frequency domains, MEG source analysis, including multiple head models and beamforming algorithms, and combines these with a suite of PLS analyses. The pipeline is open-source and modular, utilizing functions from FieldTrip (Donders, NL), AFNI (NIMH, USA), SPM8 (UCL, UK) and PLScmd (Baycrest, CAN), which are extensively supported and continually developed by their respective communities. [MEG]PLS is flexible, providing both a graphical user interface and command-line options, depending on the needs of the user. A visualization suite allows multiple types of data and analyses to be displayed and includes 4-D montage functionality. [MEG]PLS is freely available under the GNU public license (http://meg-pls.weebly.com). Copyright © 2015 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Chou, C-P; Lee, T K; Ho, C-M
2009-01-01
We examine the strong correlation effects of the d-wave superconducting state by including the Gutzwiller projection for no electron double occupancy at each lattice site. The spectral weights (SW's) for adding and removing an electron on the projected superconducting state, the ground state of the 2-dimensional t-t'-t - J model with moderate doped holes describing the high T c cuprates, are studied numerically on finite lattices and compared with the observation made by low-temperature tunneling (particle asymmetry of tunneling conductance) and angle-resolved photoemission (SW transfer from the projected Fermi liquid state) spectroscopies. The contrast with the d-wave case without projection is alo presented.
International Nuclear Information System (INIS)
Genreith, Christoph
2015-01-01
Nuclear waste needs to be characterized for its safe handling and storage. In particular long-lived actinides render the waste characterization challenging. The results described in this thesis demonstrate that Prompt Gamma Neutron Activation Analysis (PGAA) with cold neutrons is a reliable tool for the non-destructive analysis of actinides. Nuclear data required for an accurate identification and quantification of actinides was acquired. Therefore, a sample design suitable for accurate and precise measurements of prompt γ-ray energies and partial cross sections of long-lived actinides at existing PGAA facilities was presented. Using the developed sample design the fundamental prompt γ-ray data on 237 Np, 241 Am and 242 Pu were measured. The data were validated by repetitive analysis of different samples at two individual irradiation and counting facilities - the BRR in Budapest and the FRM II in Garching near Munich. Employing cold neutrons, resonance neutron capture by low energetic resonances was avoided during the experiments. This is an improvement over older neutron activation based works at thermal reactor neutron energies. 152 prompt γ-rays of 237 Np were identified, as well as 19 of 241 Am, and 127 prompt γ-rays of 242 Pu. In all cases, both high and lower energetic prompt γ-rays were identified. The most intense line of 237 Np was observed at an energy of E γ =182.82(10) keV associated with a partial capture cross section of σ γ =22.06(39) b. The most intense prompt γ-ray lines of 241 Am and of 242 Pu were observed at E γ =154.72(7) keV with σ γ =72.80(252) b and E γ =287.69(8) keV with σ γ =7.07(12) b, respectively. The measurements described in this thesis provide the first reported quantifications on partial radiative capture cross sections for 237 Np, 241 Am and 242 Pu measured simultaneously over the large energy range from 45 keV to 12 MeV. Detailed uncertainty assessments were performed and the validity of the given uncertainties was
Introduction to partial differential equations
Borthwick, David
2016-01-01
This modern take on partial differential equations does not require knowledge beyond vector calculus and linear algebra. The author focuses on the most important classical partial differential equations, including conservation equations and their characteristics, the wave equation, the heat equation, function spaces, and Fourier series, drawing on tools from analysis only as they arise.Within each section the author creates a narrative that answers the five questions: (1) What is the scientific problem we are trying to understand? (2) How do we model that with PDE? (3) What techniques can we use to analyze the PDE? (4) How do those techniques apply to this equation? (5) What information or insight did we obtain by developing and analyzing the PDE? The text stresses the interplay between modeling and mathematical analysis, providing a thorough source of problems and an inspiration for the development of methods.
Shao, Meng; Xiao, Chengsi; Sun, Jinwei; Shao, Zhuxiao; Zheng, Qiuhong
2017-12-01
The paper analyzes hydrodynamic characteristics and the strength of a novel dot-matrix oscillating wave energy converter, which is in accordance with nowadays’ research tendency: high power, high efficiency, high reliability and low cost. Based on three-dimensional potential flow theory, the paper establishes motion control equations of the wave energy converter unit and calculates wave loads and motions. On this basis, a three-dimensional finite element model of the device is built to check its strength. Through the analysis, it can be confirmed that the WEC is feasible and the research results could be a reference for wave energy’s exploration and utilization.
Directory of Open Access Journals (Sweden)
Zhiqiang Shen
2012-01-01
Full Text Available Deformation of partially composite beams under distributed loading and free vibrations of partially composite beams under various boundary conditions are examined in this paper. The weak-form quadrature element method, which is characterized by direct evaluation of the integrals involved in the variational description of a problem, is used. One quadrature element is normally sufficient for a partially composite beam regardless of the magnitude of the shear connection stiffness. The number of integration points in a quadrature element is adjustable in accordance with convergence requirement. Results are compared with those of various finite element formulations. It is shown that the weak form quadrature element solution for partially composite beams is free of slip locking, and high computational accuracy is achieved with smaller number of degrees of freedom. Besides, it is found that longitudinal inertia of motion cannot be simply neglected in assessment of dynamic behavior of partially composite beams.
Chang, Shi-Shing; Wu, John H.
1993-09-01
After the 2th world war, although the application of ultrasonic wave in industries is becoming more and more popular. But due to the restriction of the precise equivelent , experimental method and the support of the basic theoremsetc. Ultrasonic wave is not applied in precise measurement. Nowadays due to many conditions - the improvement in the production technic, the precise of the equivelent, causes to increase the application of ultrasonic wave. But it's still limited due to the lack of measurement and analysis theorem. In this paper, first we caculate translation of the stress wave (elastic wave) in material for the free surface of material by a normal impulse load. as the theorem analysis base in real application. It is applied to an experiment of film measurement. We can find the partical motion in material and the arriving time of wave front. Then we can estimate the thickness of layers and can prove the actual condition with the result of experiment. This resarch is not only in the theoretical investigation but also in setting overall the measurement system, and excutes the following three experiments: the thickness measurement of two layers, the thickness measurement of film material. the thickness measurement of air propagation. About the data processing, we relied on the frequency analysis to evalute the time difference of two overlapped ultrasonic wave signal. in the meanwhile. we also designed several computer programs to assist the sonic wave identification and signal analysis.
Ramakrishaniah, Ravikumar; Al Kheraif, Abdulaziz A; Elsharawy, Mohamed A; Alsaleh, Ayman K; Ismail Mohamed, Karem M; Rehman, Ihtesham Ur
2015-05-01
The purpose of this study was to investigate and compare the load distribution and displacement of cantilever prostheses with and without glass abutment by three dimensional finite element analysis. Micro-computed tomography was used to study the relationship between the glass abutment and the ridge. The external surface of the maxilla was scanned, and a simplified finite element model was constructed. The ZX-27 glass abutment and the maxillary first and second premolars were created and modified. The solid model of the three-unit cantilever fixed partial denture was scanned, and the fitting surface was modified with reference to the created abutments using the 3D CAD system. The finite element analysis was completed in ANSYS. The fit and total gap volume between the glass abutment and dental model were determined by Skyscan 1173 high-energy spiral micro-CT scan. The results of the finite element analysis in this study showed that the cantilever prosthesis supported by the glass abutment demonstrated significantly less stress on the terminal abutment and overall deformation of the prosthesis under vertical and oblique load. Micro-computed tomography determined a gap volume of 6.74162 mm(3). By contacting the mucosa, glass abutments transfer some amount of masticatory load to the residual alveolar ridge, thereby preventing damage to the periodontal microstructures of the terminal abutment. The passive contact of the glass abutment with the mucosa not only preserves the health of the mucosa covering the ridge but also permits easy cleaning. It is possible to increase the success rate of cantilever FPDs by supporting the cantilevered pontic with glass abutments. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Odd and even partial waves of ηπ− and η′π− in π−p→η(′)π−p at 191 GeV/c
Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buechele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Crespo, M. L.; Curiel, Q.; Torre, S. Dalla; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu; Donskov, S. V.; Doshita, N.; Duic, V.; Duennweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; jr, M. Finger; Fischer, H.; Franco, C.; Hohenesche, N. du Fresne von; Friedrich, J. M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmueller, S.; Grasso, A.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Harrach, D. von; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Hoeppner, Ch; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joerg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu A.; Kisselev, Yu; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Koenigsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Kraemer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W. -D.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlueter, T.; Schmidt, K.; Schmieden, H.; Schoenning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.
2015-01-01
Exclusive production of ηπ− and η′π− has been studied with a 191 GeV/cπ− beam impinging on a hydrogen target at COMPASS (CERN). Partial-wave analyses reveal different odd/even angular momentum (L ) characteristics in the inspected invariant mass range up to 3 GeV/c2. A striking similarity between
Pietrzak, Robert H.; Goldstein, Risë B.; Southwick, Steven M.; Grant, Bridget F.
2010-01-01
Background While it is well known that personality disorders are associated with trauma exposure and PTSD, limited nationally representative data are available on DSM-IV personality disorders that co-occur with posttraumatic stress disorder (PTSD) and partial PTSD. Methods Face-to-face interviews were conducted with 34,653 adults participating in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression analyses controlling for sociodemographics and additional psychiatric comorbidity evaluated associations of PTSD and partial PTSD with personality disorders. Results Prevalence rates of lifetime PTSD and partial PTSD were 6.4% and 6.6%, respectively. After adjustment for sociodemographic characteristics and additional psychiatric comorbidity, respondents with full PTSD were more likely than trauma controls to meet criteria for schizotypal, narcissistic, and borderline personality disorders (ORs=2.1–2.5); and respondents with partial PTSD were more likely than trauma controls to meet diagnostic criteria for borderline (OR=2.0), schizotypal (OR=1.8), and narcissistic (OR=1.6) PDs. Women with PTSD were more likely than controls to have obsessive-compulsive PD. Women with partial PTSD were more likely than controls to have antisocial PD; and men with partial PTSD were less likely than women with partial PTSD to have avoidant PD. Conclusions PTSD and partial PTSD are associated with borderline, schizotypal, and narcissistic personality disorders. Modestly higher rates of obsessive-compulsive PD were observed among women with full PTSD, and of antisocial PD among women with partial PTSD. PMID:20950823
A comparative analysis of heat waves and associated mortality in St. Louis, Missouri--1980 and 1995.
Smoyer, K E
1998-08-01
This research investigates heat-related mortality during the 1980 and 1995 heat waves in St. Louis, Missouri. St. Louis has a long history of extreme summer weather, and heat-related mortality is a public health concern. Heat waves are defined as days with apparent temperatures exceeding 40.6 degrees C (105 degrees F). The study uses a multivariate analysis to investigate the relationship between mortality and heat wave intensity, duration, and timing within the summer season. The heat wave of 1980 was more severe and had higher associated mortality than that of 1995. To learn if changing population characteristics, in addition to weather conditions, contributed to this difference, changes in population vulnerability between 1980 and 1995 are evaluated under simulated heat wave conditions. The findings show that St. Louis remains at risk of heat wave mortality. In addition, there is evidence that vulnerability has increased despite increased air-conditioning penetration and public health interventions.
Statistical analysis of monochromatic whistler waves near the Moon detected by Kaguya
Directory of Open Access Journals (Sweden)
Y. Tsugawa
2011-05-01
Full Text Available Observations are presented of monochromatic whistler waves near the Moon detected by the Lunar Magnetometer (LMAG on board Kaguya. The waves were observed as narrowband magnetic fluctuations with frequencies close to 1 Hz, and were mostly left-hand polarized in the spacecraft frame. We performed a statistical analysis of the waves to identify the distributions of their intensity and occurrence. The results indicate that the waves were generated by the solar wind interaction with lunar crustal magnetic anomalies. The conditions for observation of the waves strongly depend on the solar zenith angle (SZA, and a high occurrence rate is recognized in the region of SZA between 40° to 90° with remarkable north-south and dawn-dusk asymmetries. We suggest that ion beams reflected by the lunar magnetic anomalies are a possible source of the waves.
Inclusion of Structural Flexibility in Design Load Analysis for Wave Energy Converters: Preprint
Energy Technology Data Exchange (ETDEWEB)
Guo, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); van Rij, Jennifer A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tom, Nathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-08-14
Hydroelastic interactions, caused by ocean wave loading on wave energy devices with deformable structures, are studied in the time domain. A midfidelity, hybrid modeling approach of rigid-body and flexible-body dynamics is developed and implemented in an open-source simulation tool for wave energy converters (WEC-Sim) to simulate the dynamic responses of wave energy converter component structural deformations under wave loading. A generalized coordinate system, including degrees of freedom associated with rigid bodies, structural modes, and constraints connecting multiple bodies, is utilized. A simplified method of calculating stress loads and sectional bending moments is implemented, with the purpose of sizing and designing wave energy converters. Results calculated using the method presented are verified with those of high-fidelity fluid-structure interaction simulations, as well as low-fidelity, frequency-domain, boundary element method analysis.
Wave energy resource of Brazil: An analysis from 35 years of ERA-Interim reanalysis data
Araújo, Alex Maurício
2017-01-01
This paper presents a characterization of the wave power resource and an analysis of the wave power output for three (AquaBuoy, Pelamis and Wave Dragon) different wave energy converters (WEC) over the Brazilian offshore. To do so it used a 35 years reanalysis database from the ERA-Interim project. Annual and seasonal statistical analyzes of significant height and energy period were performed, and the directional variability of the incident waves were evaluated. The wave power resource was characterized in terms of the statistical parameters of mean, maximum, 95th percentile and standard deviation, and in terms of the temporal variability coefficients COV, SV e MV. From these analyses, the total annual wave power resource available over the Brazilian offshore was estimated in 89.97 GW, with largest mean wave power of 20.63 kW/m in the southernmost part of the study area. The analysis of the three WEC was based in the annual wave energy output and in the capacity factor. The higher capacity factor was 21.85% for Pelamis device at the southern region of the study area. PMID:28817731
Wave energy resource of Brazil: An analysis from 35 years of ERA-Interim reanalysis data.
Espindola, Rafael Luz; Araújo, Alex Maurício
2017-01-01
This paper presents a characterization of the wave power resource and an analysis of the wave power output for three (AquaBuoy, Pelamis and Wave Dragon) different wave energy converters (WEC) over the Brazilian offshore. To do so it used a 35 years reanalysis database from the ERA-Interim project. Annual and seasonal statistical analyzes of significant height and energy period were performed, and the directional variability of the incident waves were evaluated. The wave power resource was characterized in terms of the statistical parameters of mean, maximum, 95th percentile and standard deviation, and in terms of the temporal variability coefficients COV, SV e MV. From these analyses, the total annual wave power resource available over the Brazilian offshore was estimated in 89.97 GW, with largest mean wave power of 20.63 kW/m in the southernmost part of the study area. The analysis of the three WEC was based in the annual wave energy output and in the capacity factor. The higher capacity factor was 21.85% for Pelamis device at the southern region of the study area.
Wave energy resource of Brazil: An analysis from 35 years of ERA-Interim reanalysis data.
Directory of Open Access Journals (Sweden)
Rafael Luz Espindola
Full Text Available This paper presents a characterization of the wave power resource and an analysis of the wave power output for three (AquaBuoy, Pelamis and Wave Dragon different wave energy converters (WEC over the Brazilian offshore. To do so it used a 35 years reanalysis database from the ERA-Interim project. Annual and seasonal statistical analyzes of significant height and energy period were performed, and the directional variability of the incident waves were evaluated. The wave power resource was characterized in terms of the statistical parameters of mean, maximum, 95th percentile and standard deviation, and in terms of the temporal variability coefficients COV, SV e MV. From these analyses, the total annual wave power resource available over the Brazilian offshore was estimated in 89.97 GW, with largest mean wave power of 20.63 kW/m in the southernmost part of the study area. The analysis of the three WEC was based in the annual wave energy output and in the capacity factor. The higher capacity factor was 21.85% for Pelamis device at the southern region of the study area.
Kim, Jeong-Man; Koo, Min-Mo; Jeong, Jae-Hoon; Hong, Keyyong; Cho, Il-Hyoung; Choi, Jang-Young
2017-05-01
This paper reports the design and analysis of a tubular permanent magnet linear generator (TPMLG) for a small-scale wave-energy converter. The analytical field computation is performed by applying a magnetic vector potential and a 2-D analytical model to determine design parameters. Based on analytical solutions, parametric analysis is performed to meet the design specifications of a wave-energy converter (WEC). Then, 2-D FEA is employed to validate the analytical method. Finally, the experimental result confirms the predictions of the analytical and finite element analysis (FEA) methods under regular and irregular wave conditions.
Hamiltonian analysis of fast wave current drive in tokamak plasmas
Energy Technology Data Exchange (ETDEWEB)
Becoulet, A; Fraboulet, D; Giruzzi, G; Moreau, D; Saoutic, B [Association Euratom-CEA, Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Chinardet, J [CISI Ingenierie, Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France)
1993-12-01
The Hamiltonian formalism is used to analyze the direct resonant interaction between the fast magnetosonic wave and the electrons in a tokamak plasma. The intrinsic stochasticity of the electron phase space trajectories is derived, and together with extrinsic de-correlation processes, assesses the validity of the quasilinear approximation for the kinetic studies of fast wave current drive (FWCD). A full-wave resolution of the Maxwell-Vlasov set of equations provides the exact pattern of the wave fields in a complete tokamak geometry, for a realistic antenna spectrum. The local quasilinear diffusion tensor is derived from the wave fields, and is used for a computation of the driven current and deposited power profiles, the current drive efficiency, including possible non-linear effects in the kinetic equation. Several applications of FWCD on existing and future machines are given, as well as results concerning combination of FWCD with other non inductive current drive methods. An analytical expression for the current drive efficiency is given in the high single-pass absorption regimes. (authors). 20 figs., 1 tab., 26 refs.
Hamiltonian analysis of fast wave current drive in tokamak plasmas
International Nuclear Information System (INIS)
Becoulet, A.; Fraboulet, D.; Giruzzi, G.; Moreau, D.; Saoutic, B.
1993-12-01
The Hamiltonian formalism is used to analyze the direct resonant interaction between the fast magnetosonic wave and the electrons in a tokamak plasma. The intrinsic stochasticity of the electron phase space trajectories is derived, and together with extrinsic de-correlation processes, assesses the validity of the quasilinear approximation for the kinetic studies of fast wave current drive (FWCD). A full-wave resolution of the Maxwell-Vlasov set of equations provides the exact pattern of the wave fields in a complete tokamak geometry, for a realistic antenna spectrum. The local quasilinear diffusion tensor is derived from the wave fields, and is used for a computation of the driven current and deposited power profiles, the current drive efficiency, including possible non-linear effects in the kinetic equation. Several applications of FWCD on existing and future machines are given, as well as results concerning combination of FWCD with other non inductive current drive methods. An analytical expression for the current drive efficiency is given in the high single-pass absorption regimes. (authors). 20 figs., 1 tab., 26 refs
Urban Heat Wave Vulnerability Analysis Considering Climate Change
JE, M.; KIM, H.; Jung, S.
2017-12-01
Much attention has been paid to thermal environments in Seoul City in South Korea since 2016 when the worst heatwave in 22 years. It is necessary to provide a selective measure by singling out vulnerable regions in advance to cope with the heat wave-related damage. This study aims to analyze and categorize vulnerable regions of thermal environments in the Seoul and analyzes and discusses the factors and risk factors for each type. To do this, this study conducted the following processes: first, based on the analyzed various literature reviews, indices that can evaluate vulnerable regions of thermal environment are collated. The indices were divided into climate exposure index related to temperature, sensitivity index including demographic, social, and economic indices, and adaptation index related to urban environment and climate adaptation policy status. Second, significant variables were derived to evaluate a vulnerable region of thermal environment based on the summarized indices in the above. this study analyzed a relationship between the number of heat-related patients in Seoul and variables that affected the number using multi-variate statistical analysis to derive significant variables. Third, the importance of each variable was calculated quantitatively by integrating the statistical analysis results and analytic hierarchy process (AHP) method. Fourth, a distribution of data for each index was identified based on the selected variables and indices were normalized and overlapped. Fifth, For the climate exposure index, evaluations were conducted as same as the current vulnerability evaluation method by selecting future temperature of Seoul predicted through the representative concentration pathways (RCPs) climate change scenarios as an evaluation variable. The results of this study can be utilized as foundational data to establish a countermeasure against heatwave in Seoul. Although it is limited to control heatwave occurrences itself completely, improvements
Growth and proteomic analysis of tomato fruit under partial root-zone drying.
Marjanović, Milena; Stikić, Radmila; Vucelić-Radović, Biljana; Savić, Sladjana; Jovanović, Zorica; Bertin, Nadia; Faurobert, Mireille
2012-06-01
The effects of partial root-zone drying (PRD) on tomato fruit growth and proteome in the pericarp of cultivar Ailsa Craig were investigated. The PRD treatment was 70% of water applied to fully irrigated (FI) plants. PRD reduced the fruit number and slightly increased the fruit diameter, whereas the total fruit fresh weight (FW) and dry weight (DW) per plant did not change. Although the growth rate was higher in FI than in PRD fruits, the longer period of cell expansion resulted in bigger PRD fruits. Proteins were extracted from pericarp tissue at two fruit growth stages (15 and 30 days post-anthesis [dpa]), and submitted to proteomic analysis including two-dimensional gel electrophoresis and mass spectrometry for identification. Proteins related to carbon and amino acid metabolism indicated that slower metabolic flux in PRD fruits may be the cause of a slower growth rate compared to FI fruits. The increase in expression of the proteins related to cell wall, energy, and stress defense could allow PRD fruits to increase the duration of fruit growth compared to FI fruits. Upregulation of some of the antioxidative enzymes during the cell expansion phase of PRD fruits appears to be related to their role in protecting fruits against the mild stress induced by PRD.
International Nuclear Information System (INIS)
Kim, Jong-Yun; Choi, Yong Suk; Park, Yong Joon; Jung, Sung-Hee
2009-01-01
Neutron spectrometry, based on the scattering of high energy fast neutrons from a radioisotope and slowing-down by the light hydrogen atoms, is a useful technique for non-destructive, quantitative measurement of hydrogen content because it has a large measuring volume, and is not affected by temperature, pressure, pH value and color. The most common choice for radioisotope neutron source is 252 Cf or 241 Am-Be. In this study, 252 Cf with a neutron flux of 6.3x10 6 n/s has been used as an attractive neutron source because of its high flux neutron and weak radioactivity. Pulse-height neutron spectra have been obtained by using in-house built radioisotopic neutron spectrometric system equipped with 3 He detector and multi-channel analyzer, including a neutron shield. As a preliminary study, polyethylene block (density of ∼0.947 g/cc and area of 40 cmx25 cm) was used for the determination of hydrogen content by using multivariate calibration models, depending on the thickness of the block. Compared with the results obtained from a simple linear calibration model, partial least-squares regression (PLSR) method offered a better performance in a quantitative data analysis. It also revealed that the PLSR method in a neutron spectrometric system can be promising in the real-time, online monitoring of the powder process to determine the content of any type of molecules containing hydrogen nuclei.
International Nuclear Information System (INIS)
Xia, X.H.; Chen, Y.B.; Li, J.S.; Tasawar, H.; Alsaedi, A.; Chen, G.Q.
2014-01-01
To cope with the excessive growth of energy consumption, the Chinese government has been trying to strengthen the energy regulation system by introducing new initiatives that aim at controlling the total amount of energy consumption. A partial frontier analysis is performed in this paper to make a comparative assessment of the combinations of possible energy conservation objectives, new constraints and regulation strategies. According to the characteristics of the coordination of existing regulation structure and the optimality of regulation strategy, four scenarios are constructed and regional responsibilities are reasonably divided by fully considering the production technology in the economy. The relative importance of output objectives and the total amount controlling is compared and the impacts on the regional economy caused by the changes of regulation strategy are also evaluated for updating regulation policy. - Highlights: • New initiatives to control the total amount of energy consumption are evaluated. • Twenty-four regulation strategies and four scenarios are designed and compared. • Crucial regions for each sector and regional potential are identified. • The national goals of energy abatement are decomposed into regional responsibilities. • The changes of regulation strategy are evaluated for updating regulation policy
Lo, Yen-Li; Pan, Wen-Harn; Hsu, Wan-Lun; Chien, Yin-Chu; Chen, Jen-Yang; Hsu, Mow-Ming; Lou, Pei-Jen; Chen, I-How; Hildesheim, Allan; Chen, Chien-Jen
2016-01-01
Evidence on the association between dietary component, dietary pattern and nasopharyngeal carcinoma (NPC) is scarce. A major challenge is the high degree of correlation among dietary constituents. We aimed to identify dietary pattern associated with NPC and to illustrate the dose-response relationship between the identified dietary pattern scores and the risk of NPC. Taking advantage of a matched NPC case-control study, data from a total of 319 incident cases and 319 matched controls were analyzed. Dietary pattern was derived employing partial least square discriminant analysis (PLS-DA) performed on energy-adjusted food frequencies derived from a 66-item food-frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with multiple conditional logistic regression models, linking pattern scores and NPC risk. A high score of the PLS-DA derived pattern was characterized by high intakes of fruits, milk, fresh fish, vegetables, tea, and eggs ordered by loading values. We observed that one unit increase in the scores was associated with a significantly lower risk of NPC (ORadj = 0.73, 95% CI = 0.60-0.88) after controlling for potential confounders. Similar results were observed among Epstein-Barr virus seropositive subjects. An NPC protective diet is indicated with more phytonutrient-rich plant foods (fruits, vegetables), milk, other protein-rich foods (in particular fresh fish and eggs), and tea. This information may be used to design potential dietary regimen for NPC prevention.
Niang, Oumar; Thioune, Abdoulaye; El Gueirea, Mouhamed Cheikh; Deléchelle, Eric; Lemoine, Jacques
2012-09-01
The major problem with the empirical mode decomposition (EMD) algorithm is its lack of a theoretical framework. So, it is difficult to characterize and evaluate this approach. In this paper, we propose, in the 2-D case, the use of an alternative implementation to the algorithmic definition of the so-called "sifting process" used in the original Huang's EMD method. This approach, especially based on partial differential equations (PDEs), was presented by Niang in previous works, in 2005 and 2007, and relies on a nonlinear diffusion-based filtering process to solve the mean envelope estimation problem. In the 1-D case, the efficiency of the PDE-based method, compared to the original EMD algorithmic version, was also illustrated in a recent paper. Recently, several 2-D extensions of the EMD method have been proposed. Despite some effort, 2-D versions for EMD appear poorly performing and are very time consuming. So in this paper, an extension to the 2-D space of the PDE-based approach is extensively described. This approach has been applied in cases of both signal and image decomposition. The obtained results confirm the usefulness of the new PDE-based sifting process for the decomposition of various kinds of data. Some results have been provided in the case of image decomposition. The effectiveness of the approach encourages its use in a number of signal and image applications such as denoising, detrending, or texture analysis.
Energy Technology Data Exchange (ETDEWEB)
Kanema, T [Chishitsu-Keisoku Co. Ltd., Tokyo (Japan)
1997-10-22
With an objective to elucidate change in velocity of elastic waves in association with water pressure increase in a sand bed below the groundwater level in a shallow portion of the ground, a measurement experiment was carried out on P-wave velocity in sand samples with partial air saturation. The experiment has used fine sand having an equivalent coefficient of 2.40, a soil particle density of 2.68 g/cm {sup 3} or 60%, and a grain size of 0.36 mm. Inside the water-filled sand sample, two accelerometers were embedded 20 cm apart from each other as vibration receivers. An electromagnetic hammer for P-wave was used as the vibration source. In the experiment, measurement was carried out on the P-wave velocity in association with increase in pore water pressure by applying water pressure afresh to the water-filled sample. As a result of the experiment, the following matters were disclosed: the P-wave velocity increases as the pore water pressure was increased, and a phenomenon was recognized that the dominant frequency changes into high frequency; the degree of increase in the P-wave velocity varies depending on initial saturation of the sample; and bubbles in the pore fluid have their volume decreased due to compression resulted from increased pore water pressure and dissolution of air into the pore water. 6 refs., 11 figs.
T-wave morphology analysis of competitive athletes
DEFF Research Database (Denmark)
Hong, L; Andersen, Lars Juel; Graff, Claus
2015-01-01
BACKGROUND: T-wave morphology has been shown to be more sensitive than QT and QTc interval to describe repolarization abnormalities. The electrocardiogram (ECG) performed in athletes may manifest abnormalities, including repolarization alterations. The aim of this study was to investigate...... the characteristics of T-wave morphology features in athletes. METHODS: Eighty male elite athletes, consisting of 40 Tour de France cyclists (age 27±5years), 40 soccer players (age 26±6years) and 40 healthy men (age 27±5years) were included. RESULTS: Sinus bradycardia, left ventricular (LV) hypertrophy, incomplete...... interval, and repolarization features than the control group. CONCLUSIONS: T-wave morphology of athletes is different from non-athletes, depending of the sport. Decreased potassium current in cardiomyocytes associated with LVH may contribute to these changes....
2005-03-01
picture at 22/00Z.............50 x Figure 24. Case 5 – wave parameters........................51 Figure 25. Evolution of energy density (arrow...equation or energy balance equation: . in nl ds F v F S S S S t ∂ + ∇ = ≡ + + ∂ r (1) where ( , ; , )F f x tθ r is the two dimensional...collected from an offshore directional Seawatch buoy, in the vicinity of Cape Silleiro, Rayo Silleiro 19 (“E1”), (Figure 3), was provided by the
Predictors of Local Recurrence Following Accelerated Partial Breast Irradiation: A Pooled Analysis
International Nuclear Information System (INIS)
Shah, Chirag; Wilkinson, John Ben; Lyden, Maureen; Beitsch, Peter; Vicini, Frank A.
2012-01-01
Purpose: To analyze a pooled set of nearly 2,000 patients treated on the American Society of Breast Surgeons (ASBS) Mammosite Registry Trial and at William Beaumont Hospital (WBH) to identify factors associated with local recurrence following accelerated partial breast irradiation (APBI). Methods and Materials: A total of 1,961 women underwent partial breast irradiation between April 1993 and November 2010 as part of the ASBS Registry Trial or at WBH. Rates of ipsilateral breast tumor recurrence (IBTR), regional recurrence (RR), distant metastases (DM), disease-free survival (DFS), cause-specific survival (CSS), and overall survival (OS) were analyzed for each group and for the pooled cohort. Clinical, pathologic, and treatment-related variables were analyzed including age, tumor stage/size, estrogen receptor status, surgical margins, and lymph node status to determine their association with IBTR. Results: The two groups weres similar, but WBH patients were more frequently node positive, had positive margins, and were less likely to be within the American Society for Radiation Oncology-unsuitable group. At 5 years, the rates of IBTR, RR, DM, DFS, CSS, and OS for the pooled group of patients were 2.9%, 0.5%, 2.4%, 89.1%, 98.5%, and 91.8%, respectively. The 5-year rate of true recurrence/marginal miss was 0.8%. Univariate analysis of IBTR found that negative estrogen receptor status (odds ratio [OR], 2.83, 95% confidence interval 1.55–5.13, p = 0.0007) was the only factor significantly associated with IBTR, while a trend was seen for age less than 50 (OR 1.80, 95% confidence interval 0.90–3.58, p = 0.10). Conclusions: Excellent 5-year outcomes were seen following APBI in over 1,900 patients. Estrogen receptor negativity was the only factor associated with IBTR, while a trend for age less than 50 was noted. Significant differences in factors associated with IBTR were noted between cohorts, suggesting that factors driving IBTR may be predicated based on the risk
Statistical analysis of s-wave neutron reduced widths
International Nuclear Information System (INIS)
Pandita Anita; Agrawal, H.M.
1992-01-01
The fluctuations of the s-wave neutron reduced widths for many nuclei have been analyzed with emphasis on recent measurements by a statistical procedure which is based on the method of maximum likelihood. It is shown that the s-wave neutron reduced widths of nuclei follow single channel Porter Thomas distribution (x 2 -distribution with degree of freedom ν = 1) for most of the cases. However there are apparent deviations from ν = 1 and possible explanation and significance of this deviation is given. These considerations are likely to modify the evaluation of neutron cross section. (author)
Tsivian, Matvey; Ulusoy, Said; Abern, Michael; Wandel, Ayelet; Sidi, A Ami; Tsivian, Alexander
2012-10-01
Anatomic parameters determining renal mass complexity have been used in a number of proposed scoring systems despite lack of a critical analysis of their independent contributions. We sought to assess the independent contribution of anatomic parameters on perioperative outcomes of laparoscopic partial nephrectomy (LPN). Preoperative imaging studies were reviewed for 147 consecutive patients undergoing LPN for a single renal mass. Renal mass anatomy was recorded: Size, growth pattern (endo-/meso-/exophytic), centrality (central/hilar/peripheral), anterior/posterior, lateral/medial, polar location. Multivariable models were used to determine associations of anatomic parameters with warm ischemia time (WIT), operative time (OT), estimated blood loss (EBL), intra- and postoperative complications, as well as renal function. All models were adjusted for the learning curve and relevant confounders. Median (range) tumor size was 3.3 cm (1.5-11 cm); 52% were central and 14% hilar. While 44% were exophytic, 23% and 33% were mesophytic and endophytic, respectively. Anatomic parameters did not uniformly predict perioperative outcomes. WIT was associated with tumor size (P=0.068), centrality (central, P=0.016; hilar, P=0.073), and endophytic growth pattern (P=0.017). OT was only associated with tumor size (Panatomic parameter predicted EBL. Tumor centrality increased the odds of overall and intraoperative complications, without reaching statistical significance. Postoperative renal function was not associated with any of the anatomic parameters considered after adjustment for baseline function and WIT. Learning curve, considered as a confounder, was independently associated with reduced WIT and OT as well as reduced odds of intraoperative complications. This study provides a detailed analysis of the independent impact of renal mass anatomic parameters on perioperative outcomes. Our findings suggest diverse independent contributions of the anatomic parameters to the
Simoens, Steven
2011-01-01
This study aims to compute the budget impact of lacosamide, a new adjunctive therapy for partial-onset seizures in epilepsy patients from 16 years of age who are uncontrolled and having previously used at least three anti-epileptic drugs from a Belgian healthcare payer perspective. The budget impact analysis compared the 'world with lacosamide' to the 'world without lacosamide' and calculated how a change in the mix of anti-epileptic drugs used to treat uncontrolled epilepsy would impact drug spending from 2008 to 2013. Data on the number of patients and on the market shares of anti-epileptic drugs were taken from Belgian sources and from the literature. Unit costs of anti-epileptic drugs originated from Belgian sources. The budget impact was calculated from two scenarios about the market uptake of lacosamide. The Belgian target population is expected to increase from 5333 patients in 2008 to 5522 patients in 2013. Assuming that the market share of lacosamide increases linearly over time and is taken evenly from all other anti-epileptic drugs (AEDs), the budget impact of adopting adjunctive therapy with lacosamide increases from €5249 (0.1% of reference drug budget) in 2008 to €242,700 (4.7% of reference drug budget) in 2013. Assuming that 10% of patients use standard AED therapy plus lacosamide, the budget impact of adopting adjunctive therapy with lacosamide is around €800,000-900,000 per year (or 16.7% of the reference drug budget). Adjunctive therapy with lacosamide would raise drug spending for this patient population by as much as 16.7% per year. However, this budget impact analysis did not consider the fact that lacosamide reduces costs of seizure management and withdrawal. The literature suggests that, if savings in other healthcare costs are taken into account, adjunctive therapy with lacosamide may be cost saving.
Wavelet Transform Based Higher Order Statistical Analysis of Wind and Wave Time Histories
Habib Huseni, Gulamhusenwala; Balaji, Ramakrishnan
2017-10-01
Wind, blowing on the surface of the ocean, imparts the energy to generate the waves. Understanding the wind-wave interactions is essential for an oceanographer. This study involves higher order spectral analyses of wind speeds and significant wave height time histories, extracted from European Centre for Medium-Range Weather Forecast database at an offshore location off Mumbai coast, through continuous wavelet transform. The time histories were divided by the seasons; pre-monsoon, monsoon, post-monsoon and winter and the analysis were carried out to the individual data sets, to assess the effect of various seasons on the wind-wave interactions. The analysis revealed that the frequency coupling of wind speeds and wave heights of various seasons. The details of data, analysing technique and results are presented in this paper.
Sronsri, Chuchai; Boonchom, Banjong
2018-04-01
A simple precipitating method was used to synthesize effectively a partially metal-doped phosphate hydrate (Mn0.9Mg0.1HPO4·3H2O), whereas the thermal decomposition process of the above hydrate precursor was used to obtain Mn1.8Mg0.2P2O7 and LiMn0.9Mg0.1PO4 compounds under different conditions. To separate the overlapping thermal decomposition peak, a deconvolution technique was used, and the separated peak was applied to calculate the water content. The factor group splitting analysis was used to exemplify their vibrational spectra obtained from normal vibrations of HPO42-, H2O, P2O74- and PO43- functional groups. Further, the deconvoluted bending mode of water was clearly observed. Mn0.9Mg0.1HPO4·3H2O was observed in the orthorhombic crystal system with the space group of Pbca (D2h15). The formula units per unit cell were found to be eight (Z = 8), and the site symmetric type of HPO42- was observed as Cs. For the HPO42- unit, the correlation filed splitting analysis of type C3v - Cs - D2h15 was calculated and had 96 internal modes, whereas H2O in the above hydrate was symbolized as C2v - Cs - D2h15 and had 24 modes. The symbol C2v - Cs - C2h3 was used for the correlation filed splitting analysis of P2O74- in Mn1.8Mg0.2P2O7 (monoclinic, C2/m (C2h3), Z = 2, and 42 modes). Finally, the symbol Td - Cs - D2h16 was used for the correlation filed splitting analysis of PO43- in LiMn0.9Mg0.1PO4 (orthorhombic, Pnma (D2h16), Z = 4, and 36 modes).
International Nuclear Information System (INIS)
Boccard, Julien; Rudaz, Serge
2016-01-01
Many experimental factors may have an impact on chemical or biological systems. A thorough investigation of the potential effects and interactions between the factors is made possible by rationally planning the trials using systematic procedures, i.e. design of experiments. However, assessing factors' influences remains often a challenging task when dealing with hundreds to thousands of correlated variables, whereas only a limited number of samples is available. In that context, most of the existing strategies involve the ANOVA-based partitioning of sources of variation and the separate analysis of ANOVA submatrices using multivariate methods, to account for both the intrinsic characteristics of the data and the study design. However, these approaches lack the ability to summarise the data using a single model and remain somewhat limited for detecting and interpreting subtle perturbations hidden in complex Omics datasets. In the present work, a supervised multiblock algorithm based on the Orthogonal Partial Least Squares (OPLS) framework, is proposed for the joint analysis of ANOVA submatrices. This strategy has several advantages: (i) the evaluation of a unique multiblock model accounting for all sources of variation; (ii) the computation of a robust estimator (goodness of fit) for assessing the ANOVA decomposition reliability; (iii) the investigation of an effect-to-residuals ratio to quickly evaluate the relative importance of each effect and (iv) an easy interpretation of the model with appropriate outputs. Case studies from metabolomics and transcriptomics, highlighting the ability of the method to handle Omics data obtained from fixed-effects full factorial designs, are proposed for illustration purposes. Signal variations are easily related to main effects or interaction terms, while relevant biochemical information can be derived from the models. - Highlights: • A new method is proposed for the analysis of Omics data generated using design of experiments
Energy Technology Data Exchange (ETDEWEB)
Boccard, Julien, E-mail: julien.boccard@unige.ch; Rudaz, Serge
2016-05-12
Many experimental factors may have an impact on chemical or biological systems. A thorough investigation of the potential effects and interactions between the factors is made possible by rationally planning the trials using systematic procedures, i.e. design of experiments. However, assessing factors' influences remains often a challenging task when dealing with hundreds to thousands of correlated variables, whereas only a limited number of samples is available. In that context, most of the existing strategies involve the ANOVA-based partitioning of sources of variation and the separate analysis of ANOVA submatrices using multivariate methods, to account for both the intrinsic characteristics of the data and the study design. However, these approaches lack the ability to summarise the data using a single model and remain somewhat limited for detecting and interpreting subtle perturbations hidden in complex Omics datasets. In the present work, a supervised multiblock algorithm based on the Orthogonal Partial Least Squares (OPLS) framework, is proposed for the joint analysis of ANOVA submatrices. This strategy has several advantages: (i) the evaluation of a unique multiblock model accounting for all sources of variation; (ii) the computation of a robust estimator (goodness of fit) for assessing the ANOVA decomposition reliability; (iii) the investigation of an effect-to-residuals ratio to quickly evaluate the relative importance of each effect and (iv) an easy interpretation of the model with appropriate outputs. Case studies from metabolomics and transcriptomics, highlighting the ability of the method to handle Omics data obtained from fixed-effects full factorial designs, are proposed for illustration purposes. Signal variations are easily related to main effects or interaction terms, while relevant biochemical information can be derived from the models. - Highlights: • A new method is proposed for the analysis of Omics data generated using design of
Directory of Open Access Journals (Sweden)
R. Ramaprabha
2015-06-01
Full Text Available Mismatching effects due to partial shaded conditions are the major drawbacks existing in today’s photovoltaic (PV systems. These mismatch effects are greatly reduced in distributed PV system architecture where each panel is effectively decoupled from its neighboring panel. To obtain the optimal operation of the PV panels, maximum power point tracking (MPPT techniques are used. In partial shaded conditions, detecting the maximum operating point is difficult as the characteristic curves are complex with multiple peaks. In this paper, a neural network control technique is employed for MPPT. Detailed analyses were carried out on MPPT controllers in centralized and distributed architecture under partial shaded environments. The efficiency of the MPPT controllers and the effectiveness of the proposed control technique under partial shaded environments was examined using MATLAB software. The results were validated through experimentation.
Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt; Dam, Nico
2017-01-01
A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate
Analysis of human skin tissue by millimeter-wave reflectometry
Smulders, P.F.M.
2013-01-01
Background/pupose: Millimeter-wave reflectometry is a potentially interesting technique to analyze the human skin in vivo in order to determine the water content locally in the skin. Purpose of this work is to investigate the possibility of skin-tissue differentiation. In addition, it addresses the
Analysis of flexural wave propagation in poroelastic composite ...
African Journals Online (AJOL)
DR OKE
dimensional solution for free vibration problem of homogeneous isotropic cylindrical ... Abousleiman and Cui (1998) presented poroelastic solutions in an inclined ...... The Biot-willis elastic coefficients for a sandstone, Journal of Applied Mechanics, Vol. ... Study of wave motions in fluid-saturated porous rocks, Journal of the ...
Distribution analysis of segmented wave sea clutter in littoral environments
CSIR Research Space (South Africa)
Strempel, MD
2015-10-01
Full Text Available are then fitted against the K-distribution. It is shown that the approach can accurately describe specific sections of the wave with a reduced error between actual and estimated distributions. The improved probability density function (PDF) representation...
Analysis of Wave Fields induced by Offshore Pile Driving
Ruhnau, M.; Heitmann, K.; Lippert, T.; Lippert, S.; von Estorff, O.
2015-12-01
Impact pile driving is the common technique to install foundations for offshore wind turbines. With each hammer strike the steel pile - often exceeding 6 m in diameter and 80 m in length - radiates energy into the surrounding water and soil, until reaching its targeted penetration depth. Several European authorities introduced limitations regarding hydroacoustic emissions during the construction process to protect marine wildlife. Satisfying these regulations made the development and application of sound mitigation systems (e.g. bubble curtains or insulation screens) inevitable, which are commonly installed within the water column surrounding the pile or even the complete construction site. Last years' advances have led to a point, where the seismic energy tunneling the sound mitigation systems through the soil and radiating back towards the water column gains importance, as it confines the maximum achievable sound mitigation. From an engineering point of view, the challenge of deciding on an effective noise mitigation layout arises, which especially requires a good understanding of the soil-dependent wave field. From a geophysical point of view, the pile acts like a very unique line source, generating a characteristic wave field dominated by inclined wave fronts, diving as well as head waves. Monitoring the seismic arrivals while the pile penetration steadily increases enables to perform quasi-vertical seismic profiling. This work is based on datasets that have been collected within the frame of three comprehensive offshore measurement campaigns during pile driving and demonstrates the potential of seismic arrivals induced by pile driving for further soil characterization.
Angle-domain Migration Velocity Analysis using Wave-equation Reflection Traveltime Inversion
Zhang, Sanzong; Schuster, Gerard T.; Luo, Yi
2012-01-01
way as wave-equation transmission traveltime inversion. The residual movemout analysis in the angle-domain common image gathers provides a robust estimate of the depth residual which is converted to the reflection traveltime residual for the velocity
Structural Modeling and Analysis of a Wave Energy Converter Applying Dynamical Substructuring Method
DEFF Research Database (Denmark)
Zurkinden, Andrew Stephen; Damkilde, Lars; Gao, Zhen
2013-01-01
to the relative stiff behavior of the arm the calculation can be reduced to a quasi-static analysis. The hydrodynamic and the structural analyses are thus performed separately. In order to reduce the computational time of the finite element calculation the main structure is modeled as a superelement......This paper deals with structural modeling and analysis of a wave energy converter. The device, called Wavestar, is a bottom fixed structure, located in a shallow water environment at the Danish Northwest coast. The analysis is concentrated on a single float and its structural arm which connects...... the WEC to a jackup structure. The wave energy converter is characterized by having an operational and survival mode. The survival mode drastically reduces the exposure to waves and therfore to the wave loads. Structural response analysis of the Wavestar arm is carried out in this study. Due...
Origin and Structure of Nearshore Internal Tides and Waves: Data Analysis and Linear Theory
National Research Council Canada - National Science Library
Hendershott, Myrl
2001-01-01
Analysis of the data set obtained during the 1996-97 summer and autumn deployments of ADCP and T-logger internal wave antennas of Mission Beach, CA, was the principle activity during the reporting period...
Henseler, Jorg; Chin, Wynne W.
2010-01-01
In social and business sciences, the importance of the analysis of interaction effects between manifest as well as latent variables steadily increases. Researchers using partial least squares (PLS) to analyze interaction effects between latent variables need an overview of the available approaches as well as their suitability. This article…
International Nuclear Information System (INIS)
Diaz Sanchidrian, C.
1989-01-01
The present paper applies dimensional analysis with spatial discrimination to transform the differential equations in partial derivatives developed in the theory of heat transmission into ordinary ones. The effectivity of the method is comparable to that methods based in transformations of uni or multiparametric groups, with the advantage of being more direct and simple. (Author)
Lopes da Silva, F.H.; Vos, J.E.; Mooibroek, J.; Rotterdam, A. van
1980-01-01
The thalamo-cortical relationships of alpha rhythms have been analysed in dogs using partial coherence function analysis. The objective was to clarify how far the large intracortical coherence commonly recorded between different cortical sites could depend on a common thalamic site. It was found
Spectro-spatial analysis of wave packet propagation in nonlinear acoustic metamaterials
Zhou, W. J.; Li, X. P.; Wang, Y. S.; Chen, W. Q.; Huang, G. L.
2018-01-01
The objective of this work is to analyze wave packet propagation in weakly nonlinear acoustic metamaterials and reveal the interior nonlinear wave mechanism through spectro-spatial analysis. The spectro-spatial analysis is based on full-scale transient analysis of the finite system, by which dispersion curves are generated from the transmitted waves and also verified by the perturbation method (the L-P method). We found that the spectro-spatial analysis can provide detailed information about the solitary wave in short-wavelength region which cannot be captured by the L-P method. It is also found that the optical wave modes in the nonlinear metamaterial are sensitive to the parameters of the nonlinear constitutive relation. Specifically, a significant frequency shift phenomenon is found in the middle-wavelength region of the optical wave branch, which makes this frequency region behave like a band gap for transient waves. This special frequency shift is then used to design a direction-biased waveguide device, and its efficiency is shown by numerical simulations.
Two-Dimensional Analysis of Cable Stayed Bridge under Wave Loading
Seeram, Madhuri; Manohar, Y.
2018-06-01
In the present study finite element analysis is performed for a modified fan type cable-stayed bridge using ANSYS Mechanical. A cable stayed bridge with two towers and main deck is considered for the present study. Dynamic analysis is performed to evaluate natural frequencies. The obtained natural frequencies and mode shapes of cable stayed bridge are compared to the existing results. Further studies have been conducted for offshore area application by increasing the pylon/tower height depending upon the water depth. Natural frequencies and mode shapes are evaluated for the cable stayed bridge for offshore area application. The results indicate that the natural periods are higher than the existing results due to the effect of increase in mass of the structure and decrease in stiffness of the pylon/tower. The cable stayed bridge is analyzed under various environmental loads such as dead, live, vehicle, seismic and wave loading. Morison equation is considered to evaluate the wave force. The sum of inertia and drag force is taken as the wave force distribution along the fluid interacting height of the pylon. Airy's wave theory is used to assess water particle kinematics, for the wave periods ranging from 5 to 20 s and unit wave height. The maximum wave force among the different regular waves is considered in the wave load case. The support reactions, moments and deflections for offshore area application are highlighted. It is observed that the maximum support reactions and support moments are obtained due to wave and earthquake loading respectively. Hence, it is concluded that the wave and earthquake forces shall be given significance in the design of cable stayed bridge.
Aeroacoustic directivity via wave-packet analysis of mean or base flows
Edstrand, Adam; Schmid, Peter; Cattafesta, Louis
2017-11-01
Noise pollution is an ever-increasing problem in society, and knowledge of the directivity patterns of the sound radiation is required for prediction and control. Directivity is frequently determined through costly numerical simulations of the flow field combined with an acoustic analogy. We introduce a new computationally efficient method of finding directivity for a given mean or base flow field using wave-packet analysis (Trefethen, PRSA 2005). Wave-packet analysis approximates the eigenvalue spectrum with spectral accuracy by modeling the eigenfunctions as wave packets. With the wave packets determined, we then follow the method of Obrist (JFM, 2009), which uses Lighthill's acoustic analogy to determine the far-field sound radiation and directivity of wave-packet modes. We apply this method to a canonical jet flow (Gudmundsson and Colonius, JFM 2011) and determine the directivity of potentially unstable wave packets. Furthermore, we generalize the method to consider a three-dimensional flow field of a trailing vortex wake. In summary, we approximate the disturbances as wave packets and extract the directivity from the wave-packet approximation in a fraction of the time of standard aeroacoustic solvers. ONR Grant N00014-15-1-2403.
Girka, Igor O.; Pavlenko, Ivan V.; Thumm, Manfred
2018-05-01
Azimuthal surface waves are electromagnetic eigenwaves of cylindrical plasma-dielectric waveguides which propagate azimuthally nearby the plasma-dielectric interface across an axial external stationary magnetic field. Their eigenfrequency in particular can belong to the electron cyclotron frequency range. Excitation of azimuthal surface waves by rotating relativistic electron flows was studied in detail recently in the case of the zeroth radial mode for which the waves' radial phase change within the layer where the electrons gyrate is small. In this case, just the plasma parameters cause the main influence on the waves' dispersion properties. In the case of the first and higher radial modes, the wave eigenfrequency is higher and the wavelength is shorter than in the case of the zeroth radial mode. This gain being of interest for practical applications can be achieved without any change in the device design. The possibility of effective excitation of the higher order radial modes of azimuthal surface waves is demonstrated here. Getting shorter wavelengths of the excited waves in the case of higher radial modes is shown to be accompanied by decreasing growth rates of the waves. The results obtained here are of interest for developing new sources of electromagnetic radiation, in nano-physics and in medical physics.
DEFF Research Database (Denmark)
Nielsen, Allan Aasbjerg
2001-01-01
) and non-negative least squares (NNLS), and the partial unmixing methods orthogonal subspace projection (OSP), constrained energy minimization (CEM) and an eigenvalue formulation alternative are dealt with. The solution to the eigenvalue formulation alternative proves to be identical to the CEM solution....... The matrix inversion involved in CEM can be avoided by working on (a subset of) orthogonally transformed data such as signal maximum autocorrelation factors, MAFs, or signal minimum noise fractions, MNFs. This will also cause the partial unmixing result to be independent of the noise isolated in the MAF....../MNFs not included in the analysis. CEM and the eigenvalue formulation alternative enable us to perform partial unmixing when we know one desired end-member spectrum only and not the full set of end-member spectra. This is an advantage over full unmixing and OSP. The eigenvalue formulation of CEM inspires us...
Statistical analysis of P-wave neutron reduced widths
International Nuclear Information System (INIS)
Joshi, G.C.; Agrawal, H.M.
2000-01-01
The fluctuations of the p-wave neutron reduced widths for fifty one nuclei have been analyzed with emphasis on recent measurements by a statistical procedure which is based on the method of maximum likelihood. It is shown that the p-wave neutron reduced widths of even-even nuclei fallow single channel Porter Thomas distribution (χ 2 -distribution with degree of freedom ν=1) for most of the cases where there are no intermediate structure. It is emphasized that the distribution in nuclei other than even-even may differ from a χ 2 -distribution with one degree of freedom. Possible explanation and significance of this deviation from ν=1 is given. (author)
Quasilinear analysis of absorption of ion Bernstein waves by electrons
International Nuclear Information System (INIS)
Cardinali, A.; Paoletti, F.; Bernabei, S.; Ono, M.
1995-01-01
The effects induced on plasma electrons by an externally launched ion Bernstein wave (IBW), in the presence of a lower hybrid wave (LHW) in the current drive regime, are studied by analytical integration of the IBW ray-tracing equations along with the amplitude transport equation (Poynting theorem). The electric field amplitude parallel and perpendicular to the external magnetic field, the quasilinear diffusion coefficient, and the modified electron distribution function are analytically calculated in the case of IBW. The analytical calculation is compared to the numerical solution obtained by using a 2-D Fokker-Planck code for the distribution function, without any approximation for the collision operator. The synergy between the IBW and LHW can be accounted for, and the absorption of the IBW power when the electron distribution function presents a tail generated by the LHW in the current drive regime can be calculated
Sensitivity of a numerical wave model on wind re-analysis datasets
Lavidas, George; Venugopal, Vengatesan; Friedrich, Daniel
2017-03-01
Wind is the dominant process for wave generation. Detailed evaluation of metocean conditions strengthens our understanding of issues concerning potential offshore applications. However, the scarcity of buoys and high cost of monitoring systems pose a barrier to properly defining offshore conditions. Through use of numerical wave models, metocean conditions can be hindcasted and forecasted providing reliable characterisations. This study reports the sensitivity of wind inputs on a numerical wave model for the Scottish region. Two re-analysis wind datasets with different spatio-temporal characteristics are used, the ERA-Interim Re-Analysis and the CFSR-NCEP Re-Analysis dataset. Different wind products alter results, affecting the accuracy obtained. The scope of this study is to assess different available wind databases and provide information concerning the most appropriate wind dataset for the specific region, based on temporal, spatial and geographic terms for wave modelling and offshore applications. Both wind input datasets delivered results from the numerical wave model with good correlation. Wave results by the 1-h dataset have higher peaks and lower biases, in expense of a high scatter index. On the other hand, the 6-h dataset has lower scatter but higher biases. The study shows how wind dataset affects the numerical wave modelling performance, and that depending on location and study needs, different wind inputs should be considered.
Pietrzak, Robert H.; Goldstein, Risë B.; Southwick, Steven M.; Grant, Bridget F.
2010-01-01
The present study used data from the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions (n=34,653) to examine lifetime Axis I psychiatric comorbidity of posttraumatic stress disorder (PTSD) in a nationally representative sample of U.S. adults. Lifetime prevalences±standard errors of PTSD and partial PTSD were 6.4%±0.18 and 6.6%±0.18, respectively. Rates of PTSD and partial PTSD were higher among women (8.6%±0.26 and 8.6%±0.26) than men (4.1%±0.19 and 4.5%±0.21). Respondents with both PTSD and partial PTSD most commonly reported unexpected death of someone close, serious illness or injury to someone close, and sexual assault as their worst stressful experiences. PTSD and partial PTSD were associated with elevated lifetime rates of mood, anxiety, and substance use disorders, and suicide attempts. Respondents with partial PTSD generally had intermediate odds of comorbid Axis I disorders and psychosocial impairment relative to trauma controls and full PTSD. PMID:21168991
Consideration on the partial moderation in criticality safety analysis of LWR fresh fuel storage
International Nuclear Information System (INIS)
Tanaka, S.; Tanimoto, R.; Suzuki, K.; Ishitobi, M.
1987-01-01
In criticality safety analyses of fuel fabrication facilities, neutron effective multiplication factor (k eff ) of a storage vault has been calculated assuming ''partial moderation'' in whole space (hereafter reffered to as unlimited partial moderation). Where the enrichment of fuels to be stored is about 3.5 % or less, calculated k eff is usually low enough to show subcriticality even in unlimited partial moderation. However, it is scheduled to elevate LWR fuels enrichment for economical higher burnup and the unlimited partial moderation would require to introduce neutron absorbers to maintain subcriticality. It is clear that this causes economical disadvantages, and hence we reconsidered this assumption to avoid such a condition. Reconsideration of the unlimited partial moderation was carried out in following steps. (1) Water quantity to be assumed in atmosphere to obtain criticality was revealed too much to realize. (2) Typical realistic water quantity in atmosphere was estimated to apply as an alternative assumption. (3) A fresh fuel assembly storage was chosen as a model array and calculations with lattice code WIMS-D 1 and Monte Calro code KENO-IV 2 were performed to compare new alternative assumption with the unlimited one. As results of the above calculations, maximum k eff of the array under the new assumption was remarkably reduced to the value less than 0.95 though the maximum k eff under the unlimited one was higher than 1.0. (author)
Comparative analysis of winch-based wave energy converters
Nachev, Aleksandar
2017-01-01
Renewable energy sources are probably the future of the mankind. The main points advocating wave energy in particular include its huge potential, low environmental impact and availability around the globe. In order to harvest that energy, however, engineers have to overcome, among others, the corrosive sea environment and the unpredictable storms as well as secure funding for research and development. A lot of effort has been put into building and testing WECs after the oil crisis in the 1970...
Singular value decomposition methods for wave propagation analysis
Czech Academy of Sciences Publication Activity Database
Santolík, Ondřej; Parrot, M.; Lefeuvre, F.
2003-01-01
Roč. 38, č. 1 (2003), s. 10-1-10-13 ISSN 0048-6604 R&D Projects: GA ČR GA205/01/1064 Grant - others:Barrande(CZ) 98039/98055 Institutional research plan: CEZ:AV0Z3042911; CEZ:MSM 113200004 Keywords : wave propagation * singular value decomposition Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.832, year: 2003
Use of offshore mooring platform for sea wave motion analysis
International Nuclear Information System (INIS)
Cicconi, G.; Dagnino, I.; Papa, L.
1979-01-01
An offshore mooring platform for supertankers may often turn out to be an ideal solution for the problem of installing a meteorological station. Its location may be particularly desirable for the purpose of recording and analysing sea wave motion in deep water or in the intermediate zone between shallow and deep water. The preliminary results obtained through the operation of a subsurface sensor at the mooring platform off the harbour of Genova are reported. (author)
Use of offshore mooring platform for sea wave motion analysis
Energy Technology Data Exchange (ETDEWEB)
Cicconi, G.; Dagnino, I.; Papa, L. (Genova Univ. (Italy). Ist. Geofisica e Geodetico); Basano, L.; Ottonello, P. (Genoa Univ. (Italy))
An offshore mooring platform for supertankers may often turn out to be an ideal solution for the problem of installing a meteorological station. Its location may be particularly desirable for the purpose of recording and analysing sea wave motion in deep water or in the intermediate zone between shallow and deep water. The preliminary results obtained through the operation of a subsurface sensor at the mooring platform off the harbour of Genova are reported.
Analysis of Periodic Errors for Synthesized-Reference-Wave Holography
Directory of Open Access Journals (Sweden)
V. Schejbal
2009-12-01
Full Text Available Synthesized-reference-wave holographic techniques offer relatively simple and cost-effective measurement of antenna radiation characteristics and reconstruction of complex aperture fields using near-field intensity-pattern measurement. These methods allow utilization of advantages of methods for probe compensations for amplitude and phasing near-field measurements for the planar and cylindrical scanning including accuracy analyses. The paper analyzes periodic errors, which can be created during scanning, using both theoretical results and numerical simulations.
Ashraf, M. A. M.; Kumar, N. S.; Yusoh, R.; Hazreek, Z. A. M.; Aziman, M.
2018-04-01
Site classification utilizing average shear wave velocity (Vs(30) up to 30 meters depth is a typical parameter. Numerous geophysical methods have been proposed for estimation of shear wave velocity by utilizing assortment of testing configuration, processing method, and inversion algorithm. Multichannel Analysis of Surface Wave (MASW) method is been rehearsed by numerous specialist and professional to geotechnical engineering for local site characterization and classification. This study aims to determine the site classification on soft and hard ground using MASW method. The subsurface classification was made utilizing National Earthquake Hazards Reduction Program (NERHP) and international Building Code (IBC) classification. Two sites are chosen to acquire the shear wave velocity which is in the state of Pulau Pinang for soft soil and Perlis for hard rock. Results recommend that MASW technique can be utilized to spatially calculate the distribution of shear wave velocity (Vs(30)) in soil and rock to characterize areas.
Analysis of efficient preconditioned defect correction methods for nonlinear water waves
DEFF Research Database (Denmark)
Engsig-Karup, Allan Peter
2014-01-01
Robust computational procedures for the solution of non-hydrostatic, free surface, irrotational and inviscid free-surface water waves in three space dimensions can be based on iterative preconditioned defect correction (PDC) methods. Such methods can be made efficient and scalable to enable...... prediction of free-surface wave transformation and accurate wave kinematics in both deep and shallow waters in large marine areas or for predicting the outcome of experiments in large numerical wave tanks. We revisit the classical governing equations are fully nonlinear and dispersive potential flow...... equations. We present new detailed fundamental analysis using finite-amplitude wave solutions for iterative solvers. We demonstrate that the PDC method in combination with a high-order discretization method enables efficient and scalable solution of the linear system of equations arising in potential flow...
International Nuclear Information System (INIS)
Zhang, Y. S.; Cai, F.; Xu, W. M.
2011-01-01
The ship motion equation with a cosine wave excitement force describes the slip moments in regular waves. A new kind of wave excitement force model, with the form as sums of cosine functions was proposed to describe ship rolling in irregular waves. Ship rolling time series were obtained by solving the ship motion equation with the fourth-order-Runger-Kutta method. These rolling time series were synthetically analyzed with methods of phase-space track, power spectrum, primary component analysis, and the largest Lyapunove exponent. Simulation results show that ship rolling presents some chaotic characteristic when the wave excitement force was applied by sums of cosine functions. The result well explains the course of ship rolling's chaotic mechanism and is useful for ship hydrodynamic study.
Investigation of interfacial wave structure using time-series analysis techniques
International Nuclear Information System (INIS)
Jayanti, S.; Hewitt, G.F.; Cliffe, K.A.
1990-09-01
The report presents an investigation into the interfacial structure in horizontal annular flow using spectral and time-series analysis techniques. Film thickness measured using conductance probes shows an interesting transition in wave pattern from a continuous low-frequency wave pattern to an intermittent, high-frequency one. From the autospectral density function of the film thickness, it appears that this transition is caused by the breaking up of long waves into smaller ones. To investigate the possibility of the wave structure being represented as a low order chaotic system, phase portraits of the time series were constructed using the technique developed by Broomhead and co-workers (1986, 1987 and 1989). These showed a banded structure when waves of relatively high frequency were filtered out. Although these results are encouraging, further work is needed to characterise the attractor. (Author)
Experimental and simulation analysis of hydrogen production by partial oxidation of methanol
Energy Technology Data Exchange (ETDEWEB)
Sikander, U. [National Univ. of Science and Technology, Islamabad (Pakistan)
2014-10-15
Partial oxidation of methanol is the only self-sustaining process for onboard production of hydrogen. For this a fixed bed catalytic reactor is designed, based on heterogeneous catalytic reaction. To develop an optimized process, simulation is carried out using ASPEN HYSYS v 7.1. Reaction kinetics is developed on the basis of Langmuir Hinshel wood model. 45:55:5 of CuO: ZnO: Al/sub 2/O/sub 3/ is used as a catalyst. Simulation results are studied in detail to understand the phenomenon of partial oxidation of methanol inside the reactor. An experimental rig is developed for hydrogen production through partial oxidation of methanol. Results obtained from process simulation and experimental work; are compared with each other. (author)
Ebert, Marcelo R
2018-01-01
This book provides an overview of different topics related to the theory of partial differential equations. Selected exercises are included at the end of each chapter to prepare readers for the “research project for beginners” proposed at the end of the book. It is a valuable resource for advanced graduates and undergraduate students who are interested in specializing in this area. The book is organized in five parts: In Part 1 the authors review the basics and the mathematical prerequisites, presenting two of the most fundamental results in the theory of partial differential equations: the Cauchy-Kovalevskaja theorem and Holmgren's uniqueness theorem in its classical and abstract form. It also introduces the method of characteristics in detail and applies this method to the study of Burger's equation. Part 2 focuses on qualitative properties of solutions to basic partial differential equations, explaining the usual properties of solutions to elliptic, parabolic and hyperbolic equations for the archetypes...
Pietrzak, Robert H.; Goldstein, Risë B.; Southwick, Steven M.; Grant, Bridget F.
2011-01-01
Objectives To present findings on the prevalence, correlates, and psychiatric comorbidity of DSM-IV posttraumatic stress disorder (PTSD) and partial PTSD in a nationally representative sample of U.S. older adults. Design, Setting, and Participants Face-to-face interviews with 9,463 adults aged 60 years and older in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. Measurements Sociodemographic correlates, worst stressful experiences, comorbid lifetime mood, anxiety, substance use, and personality disorders, psychosocial functioning, and suicide attempts. Results Lifetime prevalences±standard errors of PTSD and partial PTSD were 4.5%±0.25 and 5.5%±0.27, respectively. Rates were higher in women (5.7%±0.37 and 6.5%±0.39) than men (3.1%±0.31 and 4.3%±0.37). Older adults with PTSD most frequently identified unexpected death of someone close, serious illness or injury to someone close, and own serious or life-threatening illness as their worst stressful events. Older adults exposed to trauma but without full or partial PTSD and respondents with partial PTSD most often identified unexpected death of someone close, serious illness or injury to someone close, and indirect experience of 9/11 as their worst events. PTSD was associated with elevated odds of lifetime mood, anxiety, drug use, and borderline and narcissistic personality disorders, and decreased psychosocial functioning. Partial PTSD was associated with elevated odds of mood, anxiety, and narcissistic and schizotypal personality disorders, and poorer psychosocial functioning relative to older adults exposed to trauma but without full or partial PTSD. Conclusions PTSD among older adults in the United States is slightly more prevalent than previously reported and associated with considerable psychiatric comorbidity and psychosocial dysfunction. Partial PTSD is associated with significant psychiatric comorbidity, particularly with mood and other anxiety disorders. PMID:22522959
DEFF Research Database (Denmark)
Kjølby, Birgitte Fuglsang; Mikkelsen, Irene Klærke; Pedersen, Michael
2009-01-01
of an AIF voxel including the relaxation properties of blood and tissue. Artery orientations parallel and perpendicular to the main magnetic field were investigated and AIF voxels were modeled to either include or be situated close to a large artery. The impact of partial volume effects on quantitative...... perfusion metrics was investigated for the gradient echo pulse sequence at 1.5 T and 3.0 T. It is shown that the tissue contribution broadens and introduces fluctuations in the AIF. Furthermore, partial volume effects bias perfusion metrics in a nonlinear fashion, compromising quantitative perfusion...
Wave energy budget analysis in the Earth’s radiation belts uncovers a missing energy
Artemyev, A.V.; Agapitov, O.V.; Mourenas, D.; Krasnoselskikh, V.V.; Mozer, F.S.
2015-01-01
Whistler-mode emissions are important electromagnetic waves pervasive in the Earth’s magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth’s magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave–particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth’s radiation belts, controlled by solar activity. PMID:25975615
A New Alternative in Urban Geophysics: Multi-Channel Analysis of Surface Waves (MASW) Method
International Nuclear Information System (INIS)
Ozcep, F.
2007-01-01
Geophysical studies are increasingly being applied to geotechnical investigations as they can identify soil properties and soil boundaries. Other advantage is that many of these methods are non-invasive and environment friendly. Soil stiffness is one of the critical material parameters considered during an early stage of most foundation construction. It is related directly to the stability of structural load, especially as it relates to possible earthquake hazard. Soil lacking sufficient stiffness for a given load can experience a significant reduction in strength under earthquake shaking resulting in liquefaction, a condition responsible for tremendous amounts of damage from earthquakes around the world The multichannel analysis of surface waves (MASW) method originated from the traditional seismic exploration approach that employs multiple (twelve or more) receivers placed along a linear survey line. Main advantage is its capability of recognizing different types of seismic waves based on wave propagation characteristics such as velocity and attenuation. The MASW method utilizes this capability to discriminate the fundamental-mode Rayleigh wave against all other types of surface and body waves generated not only from the active seismic source but also from the ambient site conditions. Dispersive characteristics of seismic waves are imaged from an objective 2-D wave field transformation. The present paper indicates results from MASW survey at different urban site in Turkey. MASW techniques will prove to be important tools for obtaining shear wave velocity and evaluating liquefaction potential, soil bearing capacity and soil amplification, etc. for future geophysical and geotechnical engineering community
Pasquet, S.; Wang, W.; Holbrook, W. S.; Bodet, L.; Carr, B.; Flinchum, B. A.
2017-12-01
Estimating porosity and saturation in the shallow subsurface over large lateral scales is vitally important for understanding the development and evolution of the Critical Zone (CZ). Because elastic properties (P- and S-wave velocities) are particularly sensitive to porosity and saturation, seismic methods (in combination with petrophysical models) are effective tools for mapping CZ architecture and processes. While many studies employ P-wave refraction methods, fewer use the surface waves that are typically also recorded in those same surveys. Here we show the value of exploiting surface waves to extract supplementary shear-wave velocity (Vs) information in the CZ. We use a new, user-friendly, open-source MATLAB-based package (SWIP) to invert surface-wave data and estimate lateral variations of Vs in the CZ. Results from synthetics show that this approach enables the resolution of physical property variations in the upper 10-15 m below the surface with lateral scales of about 5 m - a vast improvement compared to P-wave tomography alone. A field example at a Yellowstone hydrothermal system also demonstrates the benefits of including Vs in the petrophysical models to estimate not only porosity but also saturation, thus highlighting subsurface gas pathways. In light of these results, we strongly suggest that surface-wave analysis should become a standard approach in CZ seismic surveys.
Shimura, Tomoya; Mori, Nobuhito; Mase, Hajime
2015-01-01
Changes in ocean surface waves elicit a variety of impacts on coastal environments. To assess the future changes in the ocean surface wave climate, several future projections of global wave climate have been simulated in previous studies. However, previously there has been little discussion about the causes behind changes in the future wave climate and the differences between projections. The objective of this study is to estimate the future changes in mean wave climate and the sensitivity of...
Reconstruction of Interfering Waves from Three Dimensional Analysis of Their Interference Pattern
Directory of Open Access Journals (Sweden)
M. T. Tavassoli
1997-04-01
Full Text Available Optical interferometry is being used as an efficient tool to analyse smooth surfaces for more than a century. Although, due to introduction of novel computer assisted analyzing techniques and array detectors, like CCD, the speed and the precision of processing have been increased tremendously, but the main equation involved is not changed. The main equation is the intensity distribution in the interference pattern of a plane reference wave and the required wave. In the paper it is shown that by analysis of the interference pattern of two unknown waves in three dimension (which is possible for coherent waves it is possible to reconstruct each wave separately. This approach has several useful applications, namely, on can do without reference plane wave in the interferometric surface analysis and, it is possible to reconstruct an unknown wave by making it to interfere with itself. This is very useful in determining the profile of laser beams and erasing the effect of atmospheric disturbances on observing astronomical objects.
International Nuclear Information System (INIS)
Hicks, D.L.; Walsh, R.T.
1976-06-01
Discrete methods for the solution of the partial differential equations arising in hydrocodes and wavecodes are presented in a tutorial fashion. By discrete methods is meant, for example, the methods of finite differences, finite elements, discretized characteristics, etc. The concepts of stability, consistency, convergence, order of accuracy, true accuracy, etc., and their relevance to the hydrocodes and wavecodes are discussed
Gomez, Rapson
2012-01-01
Objective: Generalized partial credit model, which is based on item response theory (IRT), was used to test differential item functioning (DIF) for the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.), inattention (IA), and hyperactivity/impulsivity (HI) symptoms across boys and girls. Method: To accomplish this, parents completed…
Directory of Open Access Journals (Sweden)
Korobeynikov S.M.
2017-08-01
Full Text Available In this paper, we consider the problems related to measuring and analyzing the characteristics of partial discharges which are the main instrument for oil-filled high-voltage electrical equipment diagnosing. The experiments on recording of partial discharges in transformer oil have been carried out in the “point-plane” electrode system at alternating current. The instantaneous voltage and the apparent charge have been measured depending on the root-mean-square voltage and the phase angle of partial discharges. This paper aimes at carrying out a statistical analysis of the obtained experimental results, in particular, the construction of a parametric probabilistic model of the dependence of the partial discharge inception voltage distribution on the value of the root-mean-square voltage. It differs from usual discharges which occur in liquid dielectric materials in case of sharp inhomogeneous electrode system. It has been suggested that discharges of a different type are the discharges in gas bubbles that occur when partial discharges in a liquid emerge. This assumption is confirmed by the fact that the number of such discharges increases with increasing the root-mean-square voltage value. It is the main novelty of this paper. This corresponds to the nature of the occurrence of such discharges. After rejecting the observations corresponding to discharges in gas bubbles, a parametric probabilistic model has been constructed. The model obtained makes it possible to determine the probability of partial discharge occurrence in a liquid at a given value of the instantaneous voltage depending on the root-mean-square voltage.
Analysis of a plane stress wave by the moving least squares method
Directory of Open Access Journals (Sweden)
Wojciech Dornowski
2014-08-01
Full Text Available A meshless method based on the moving least squares approximation is applied to stress wave propagation analysis. Two kinds of node meshes, the randomly generated mesh and the regular mesh are used. The nearest neighbours’ problem is developed from a triangulation that satisfies minimum edges length conditions. It is found that this method of neighbours’ choice significantly improves the solution accuracy. The reflection of stress waves from the free edge is modelled using fictitious nodes (outside the plate. The comparison with the finite difference results also demonstrated the accuracy of the proposed approach.[b]Keywords[/b]: civil engineering, meshless method, moving least squares method, elastic waves
Symmetry analysis of many-body wave functions, with applications to the nuclear shell model
International Nuclear Information System (INIS)
Novoselsky, A.; Katriel, J.
1995-01-01
The weights of the different permutational symmetry components of a nonsymmetry-adapted many-particle wave function are evaluated in terms of the expectation values of the symmetric-group class sums. This facilitates the evaluation of the weights without the construction of a complete set of symmetry adapted functions. Subspace projection operators are introduced, to be used when prior knowledge about the symmetry-species composition of a wave function is available. The permutational weight analysis of a recursively angular-momentum coupled (shell model) wave function is presented as an illustration
Gravitational-wave physics and astronomy an introduction to theory, experiment and data analysis
Creighton, Jolien D E
2011-01-01
This most up-to-date, one-stop reference combines coverage of both theory and observational techniques, with introductory sections to bring all readers up to the same level. Written by outstanding researchers directly involved with the scientific program of the Laser Interferometer Gravitational-Wave Observatory (LIGO), the book begins with a brief review of general relativity before going on to describe the physics of gravitational waves and the astrophysical sources of gravitational radiation. Further sections cover gravitational wave detectors, data analysis, and the outlook of gravitation
Development of an analysis code for pressure wave propagation, (1)
International Nuclear Information System (INIS)
Tanaka, Yoshihisa; Sakano, Kosuke; Shindo, Yoshihisa
1974-11-01
We analyzed the propagation of the pressure-wave in the piping system of SWAT-1B rig by using SWAC-5 Code. We carried out analyses on the following parts. 1) A straight pipe 2) Branches 3) A piping system The results obtained in these analyses are as follows. 1) The present our model simulates well the straight pipe and the branch with the same diameters. 2) The present our model simulates approximately the branch with the different diameters and the piping system. (auth.)
DEFF Research Database (Denmark)
This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....
Henderson, Gregory Newell
Semiconductor device dimensions are rapidly approaching a fundamental limit where drift-diffusion equations and the depletion approximation are no longer valid. In this regime, quantum effects can dominate device response. To increase further device density and speed, new devices must be designed that use these phenomena to positive advantage. In addition, quantum effects provide opportunities for a new class of devices which can perform functions previously unattainable with "conventional" semiconductor devices. This thesis has described research in the analysis of electron wave effects in semiconductors and the development of methods for the design, fabrication, and characterization of quantum devices based on these effects. First, an exact set of quantitative analogies are presented which allow the use of well understood optical design and analysis tools for the development of electron wave semiconductor devices. Motivated by these analogies, methods are presented for modeling electron wave grating diffraction using both an exact rigorous coupled-wave analysis and approximate analyses which are useful for grating design. Example electron wave grating switch and multiplexer designs are presented. In analogy to thin-film optics, the design and analysis of electron wave Fabry-Perot interference filters are also discussed. An innovative technique has been developed for testing these (and other) electron wave structures using Ballistic Electron Emission Microscopy (BEEM). This technique uses a liquid-helium temperature scanning tunneling microscope (STM) to perform spectroscopy of the electron transmittance as a function of electron energy. Experimental results show that BEEM can resolve even weak quantum effects, such as the reflectivity of a single interface between materials. Finally, methods are discussed for incorporating asymmetric electron wave Fabry-Perot filters into optoelectronic devices. Theoretical and experimental results show that such structures could
A Numerical Method for Blast Shock Wave Analysis of Missile Launch from Aircraft
Directory of Open Access Journals (Sweden)
Sebastian Heimbs
2015-01-01
Full Text Available An efficient empirical approach was developed to accurately represent the blast shock wave loading resulting from the launch of a missile from a military aircraft to be used in numerical analyses. Based on experimental test series of missile launches in laboratory environment and from a helicopter, equations were derived to predict the time- and position-dependent overpressure. The method was finally applied and validated in a structural analysis of a helicopter tail boom under missile launch shock wave loading.
Analysis of wave-like oscillations in parameters of sporadic E layer and neutral atmosphere
Mošna, Z.; Koucká Knížová, P.
2012-12-01
The present study mainly concerns the wave-like activity in the ionospheric sporadic E layer (Es) and in the lower lying stratosphere. The proposed analysis involves parameters describing the state of plasma in the sporadic E layer. Critical frequencies foEs and layer heights hEs were measured at the Pruhonice station (50°N, 14.5°E) during summer campaigns 2004, 2006 and 2008. Further, we use neutral atmosphere (temperature data at 10 hPa) data from the same time interval. The analysis concentrates on vertically propagating wave-like structures within distant atmospheric regions. By means of continuous wavelet transform (CWT) we have detected significant wave-like oscillation at periods covering tidal and planetary oscillation domains both in the Es layer parameters (some of them were reported earlier, for instance in works of Abdu et al., 2003; Pancheva and Mitchel, 2004; Pancheva et al., 2003; Šauli and Bourdillon, 2008) and in stratospheric temperature variations. Further analyses using cross wavelet transform (XWT) and wavelet coherence analysis (WTC) show that despite high wave-like activity in a wide period range, there are only limited coherent wave-like bursts present in both spectra. Such common coherent wave bursts occur on periods close to eigen-periods of the terrestrial atmosphere. We suppose that vertical coupling between atmospheric regions realized by vertically propagating planetary waves occurs predominantly on periods close to those of Rossby modes. Analysis of the phase shift between data from distant atmospheric regions reveals high variability and very likely supports the non-linear scenario of the vertical coupling provided by planetary waves.
Analysis of a time fractional wave-like equation with the homotopy analysis method
International Nuclear Information System (INIS)
Xu Hang; Cang Jie
2008-01-01
The time fractional wave-like differential equation with a variable coefficient is studied analytically. By using a simple transformation, the governing equation is reduced to two fractional ordinary differential equations. Then the homotopy analysis method is employed to derive the solutions of these equations. The accurate series solutions are obtained. Especially, when h f =h g =-1, these solutions are exactly the same as those results given by the Adomian decomposition method. The present work shows the validity and great potential of the homotopy analysis method for solving nonlinear fractional differential equations. The basic idea described in this Letter is expected to be further employed to solve other similar nonlinear problems in fractional calculus
Analysis of Peristaltic Waves & their Role in Migrating Physarum Plasmodia
Lewis, Owen; Guy, Robert
2017-11-01
The true slime mold Physarum polycephalum exhibits a vast array of sophisticated manipulations of its intracellular cytoplasm. Growing microplasmodia of physarum have been observed to adopt an elongated tadpole shape, then contract in a rhythmic, traveling wave pattern that resembles peristaltic pumping. This contraction drives a fast flow of non-gelated cytoplasm along the cell longitudinal axis. It has been hypothesized that this flow of cytoplasm is a driving factor in generating motility of the plasmodium. In this work, we use two different mathematical models to investigate how peristaltic pumping within physarum may be used to drive cellular motility. We compare the relative phase of flow and deformation waves predicted by both models to similar phase data collected from in vivo experiments using physarum plasmodia. Both models suggest that a mechanical asymmetry in the cell is required to reproduce the experimental observations. Such a mechanical asymmetry is also shown to increase the potential for cellular migration, as measured by both stress generation and migration velocity.
Directory of Open Access Journals (Sweden)
E. A. K. Ford
2008-02-01
Full Text Available Data from the Fabry-Perot Interferometers at KEOPS (Sweden, Sodankylä (Finland, and Svalbard (Norway, have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the waves that are present in the high latitude upper thermosphere to be determined. Comparisons were made between the different parameters: the atomic oxygen intensities, the thermospheric winds and temperatures, and for each parameter the distribution of frequencies of the waves was determined. No dependence on the number of waves on geomagnetic activity levels, or position in the solar cycle, was found. All the FPIs have had different detectors at various times, producing different time resolutions of the data, so comparisons between the different years, and between data from different sites, showed how the time resolution determines which waves are observed. In addition to the cutoff due to the Nyquist frequency, poor resolution observations significantly reduce the number of short-period waves (<1 h period that may be detected with confidence. The length of the dataset, which is usually determined by the length of the night, was the main factor influencing the number of long period waves (>5 h detected. Comparisons between the number of gravity waves detected at KEOPS and Sodankylä over all the seasons showed a similar proportion of waves to the number of nights used for both sites, as expected since the two sites are at similar latitudes and therefore locations with respect to the auroral oval, confirming this as a likely source region. Svalbard showed fewer waves with short periods than KEOPS data for a season when both had the same time resolution data
Blasco, H; Błaszczyński, J; Billaut, J C; Nadal-Desbarats, L; Pradat, P F; Devos, D; Moreau, C; Andres, C R; Emond, P; Corcia, P; Słowiński, R
2015-02-01
Metabolomics is an emerging field that includes ascertaining a metabolic profile from a combination of small molecules, and which has health applications. Metabolomic methods are currently applied to discover diagnostic biomarkers and to identify pathophysiological pathways involved in pathology. However, metabolomic data are complex and are usually analyzed by statistical methods. Although the methods have been widely described, most have not been either standardized or validated. Data analysis is the foundation of a robust methodology, so new mathematical methods need to be developed to assess and complement current methods. We therefore applied, for the first time, the dominance-based rough set approach (DRSA) to metabolomics data; we also assessed the complementarity of this method with standard statistical methods. Some attributes were transformed in a way allowing us to discover global and local monotonic relationships between condition and decision attributes. We used previously published metabolomics data (18 variables) for amyotrophic lateral sclerosis (ALS) and non-ALS patients. Principal Component Analysis (PCA) and Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA) allowed satisfactory discrimination (72.7%) between ALS and non-ALS patients. Some discriminant metabolites were identified: acetate, acetone, pyruvate and glutamine. The concentrations of acetate and pyruvate were also identified by univariate analysis as significantly different between ALS and non-ALS patients. DRSA correctly classified 68.7% of the cases and established rules involving some of the metabolites highlighted by OPLS-DA (acetate and acetone). Some rules identified potential biomarkers not revealed by OPLS-DA (beta-hydroxybutyrate). We also found a large number of common discriminating metabolites after Bayesian confirmation measures, particularly acetate, pyruvate, acetone and ascorbate, consistent with the pathophysiological pathways involved in ALS. DRSA provides
Pseudospectral modeling and dispersion analysis of Rayleigh waves in viscoelastic media
Zhang, K.; Luo, Y.; Xia, J.; Chen, C.
2011-01-01
Multichannel Analysis of Surface Waves (MASW) is one of the most widely used techniques in environmental and engineering geophysics to determine shear-wave velocities and dynamic properties, which is based on the elastic layered system theory. Wave propagation in the Earth, however, has been recognized as viscoelastic and the propagation of Rayleigh waves presents substantial differences in viscoelastic media as compared with elastic media. Therefore, it is necessary to carry out numerical simulation and dispersion analysis of Rayleigh waves in viscoelastic media to better understand Rayleigh-wave behaviors in the real world. We apply a pseudospectral method to the calculation of the spatial derivatives using a Chebyshev difference operator in the vertical direction and a Fourier difference operator in the horizontal direction based on the velocity-stress elastodynamic equations and relations of linear viscoelastic solids. This approach stretches the spatial discrete grid to have a minimum grid size near the free surface so that high accuracy and resolution are achieved at the free surface, which allows an effective incorporation of the free surface boundary conditions since the Chebyshev method is nonperiodic. We first use an elastic homogeneous half-space model to demonstrate the accuracy of the pseudospectral method comparing with the analytical solution, and verify the correctness of the numerical modeling results for a viscoelastic half-space comparing the phase velocities of Rayleigh wave between the theoretical values and the dispersive image generated by high-resolution linear Radon transform. We then simulate three types of two-layer models to analyze dispersive-energy characteristics for near-surface applications. Results demonstrate that the phase velocity of Rayleigh waves in viscoelastic media is relatively higher than in elastic media and the fundamental mode increases by 10-16% when the frequency is above 10. Hz due to the velocity dispersion of P
Directory of Open Access Journals (Sweden)
Dumitrescu Sorin
2016-08-01
Full Text Available The paper shows the importance of trending of partial discharge activity in assessing the insulation condition. It is presented the principle of the measurement method and the quantities that characterize partial discharges and also the criteria utilized for the assessement of the insulation condition of the hydrogenerators. Results of the measurements made on several hydrogenerators are presented, like the variation with time of the two main quantities that characterize the partial discharges, maximum magnitude, Qm and the normalized quantity, NQN over a period of about 10 years. Further, a classification of the insulation condition by 3 main and 2 intermediary categories and the definition of these categories are given. The criteria used for the assessment of the insulation condition are presented in the form of a table: quantitative criteria by the ± NQN and ± Qm values and qualitative criteria for the analysis of the 2D and 3D diagrams. At the end of each set of measurements, an analyze of the insulation condition annual evaluation is made, also a verdict is put, and of course, the recommendations made relating to the maintenance and the decisions that have been taken. The paper ends with several considerations on the method of on-line partial discharges and especially, on the conditions for valid trending activity in time.
Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films
Hines, Jacqueline H. (Inventor)
2015-01-01
A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.
International Nuclear Information System (INIS)
Lee, Jun Shin; Lee, Wook Ryun; Oh, Ki Yong; Kim, Bong Ki
2010-01-01
Understanding water hammer is very important to the prevention of excessive pressure build-up in pipelines. Many researchers have studied this phenomenon, drawing effective solutions through the time- and frequency-domain approaches. For the purposes of enhancing the advantages of the frequency-domain approach and, thereby, rendering investigations of the dynamic characteristics of pipelines more effective, we propose partial fraction expansion of the transfer function between the unsteady flow source and a given section. We simulate the proposed approach using a vibration element inserted into a simple pipeline, deducing much useful physical information pertaining to pipeline design. We conclude that locating the resonance of the vibration element between the first and second resonances of the pipeline can mitigate the excessive pressure build-up attendant on the occurrence of water hammer. Our method of partial fraction expansion is expected to be useful and effective in analyses of unsteady flows in pipelines
Pan, Suwen; Fadiga, Mohamadou L.; Mohanty, Samarendu; Welch, Mark
2006-01-01
This paper analyzed the effects of trade liberalizing reforms in the world cotton market using a partial equilibrium model. The simulation results indicated that a removal of domestic subsidies and border tariffs for cotton would increase the amount of world cotton trade by an average of 4% in the next five years and world cotton prices by an average of 12% over the same time horizon. The findings indicated that under the liberalization policy, the United States would lose part of its export ...
An analysis of beam parameters on proton-acoustic waves through an analytic approach.
Kipergil, Esra Aytac; Erkol, Hakan; Kaya, Serhat; Gulsen, Gultekin; Unlu, Mehmet Burcin
2017-06-21
It has been reported that acoustic waves are generated when a high-energy pulsed proton beam is deposited in a small volume within tissue. One possible application of proton-induced acoustics is to get real-time feedback for intra-treatment adjustments by monitoring such acoustic waves. A high spatial resolution in ultrasound imaging may reduce proton range uncertainty. Thus, it is crucial to understand the dependence of the acoustic waves on the proton beam characteristics. In this manuscript, firstly, an analytic solution for the proton-induced acoustic wave is presented to reveal the dependence of the signal on the beam parameters; then it is combined with an analytic approximation of the Bragg curve. The influence of the beam energy, pulse duration and beam diameter variation on the acoustic waveform are investigated. Further analysis is performed regarding the Fourier decomposition of the proton-acoustic signals. Our results show that the smaller spill time of the proton beam upsurges the amplitude of the acoustic wave for a constant number of protons, which is hence beneficial for dose monitoring. The increase in the energy of each individual proton in the beam leads to the spatial broadening of the Bragg curve, which also yields acoustic waves of greater amplitude. The pulse duration and the beam width of the proton beam do not affect the central frequency of the acoustic wave, but they change the amplitude of the spectral components.
Theoretical analysis and experimental study of oxygen transfer under regular and non-breaking waves
Institute of Scientific and Technical Information of China (English)
尹则高; 梁丙臣; 王乐
2013-01-01
The dissolved oxygen concentration is an important index of water quality, and the atmosphere is one of the important sources of the dissolved oxygen. In this paper, the mass conservation law and the dimensional analysis method are employed to study the oxygen transfer under regular and non-breaking waves, and a unified oxygen transfer coefficient equation is obtained with consi-deration of the effect of kinetic energy and wave period. An oxygen transfer experiment for the intermediate depth water wave is per-formed to measure the wave parameters and the dissolved oxygen concentration. The experimental data and the least squares method are used to determine the constant in the oxygen transfer coefficient equation. The experimental data and the previous reported data are also used to further validate the oxygen transfer coefficient, and the agreement is satisfactory. The unified equation shows that the oxygen transfer coefficient increases with the increase of a parameter coupled with the wave height and the wave length, but it de-creases with the increase of the wave period, which has a much greater influence on the oxygen transfer coefficient than the coupled parameter.
A theoretical analysis of the weak shock waves propagating through a bubbly flow
International Nuclear Information System (INIS)
Jun, Gu Sik; Kim, Heuy Dong; Baek, Seung Cheol
2004-01-01
Two-phase flow of liquid and gas through pipe lines are frequently encountered in nuclear power plant or industrial facility. Pressure waves which can be generated by a valve operation or any other cause in pipe lines propagate through the two-phase flow, often leading to severe noise and vibration problems or fatigue failure of pipe line system. It is of practical importance to predict the propagation characteristics of the pressure waves for the safety design for the pipe line. In the present study, a theoretical analysis is performed to understand the propagation characteristics of a weak shock wave in a bubbly flow. A wave equation is developed using a small perturbation method to analyze the weak shock wave through a bubbly flow with comparably low void fractions. It is known that the elasticity of pipe and void fraction significantly affect the propagation speed of shock wave, but the frequency of relaxation oscillation which is generated behind the shock wave is not strongly influenced by the elasticity of pipe. The present analytical results are in close agreement with existing experimental data
SHOCK WAVE ANALYSIS OF THE CONSEQUENCES OF A REACTOR ACCIDENT
Energy Technology Data Exchange (ETDEWEB)
Klickman, A E; Nicholson, R B; Nims, J B
1963-06-15
The solution to the problem of transmission and attenuation of the shock wave resulting from a large reactor accident is demonstrated for a configuration typical of many reactors. The particular configuration is that of a spherical gas bubble surrounded by one or more concentric regions of compressible material. A systematic parameter study was made in which the physical characteristics of the compressible shield regions and the expansion characteristics of a gas were assumed to be parameters. Results for seven cases are shown, and similar cases with only one important difference are compared. From these comparisons it was concluded that under certain conditions alternative materials can be substituted for reactor materials in model experiments and TNT can be used as an energy source instead of uranium. In the outer crushable region the total mass of material is the important factor. (A.G.W.)
Analysis of Insulating Material of XLPE Cables considering Innovative Patterns of Partial Discharges
Directory of Open Access Journals (Sweden)
Fernando Figueroa Godoy
2017-01-01
Full Text Available This paper aims to analyze the quality of insulation in high voltage underground cables XLPE using a prototype which classifies the following usual types of patterns of partial discharge (PD: (1 internal PD, (2 superficial PD, (3 corona discharge in air, and (4 corona discharge in oil, in addition to considering two new PD patterns: (1 false contact and (2 floating ground. The tests and measurements to obtain the patterns and study cases of partial discharges were performed at the Testing Laboratory Equipment and Materials (LEPEM of the Federal Electricity Commission of Mexico (CFE using a measuring equipment LDIC and norm IEC60270. To classify the six patterns of partial discharges mentioned above a Probabilistic Neural Network Bayesian Modified (PNNBM method having the feature of using a large amount of data will be used and it is not saturated. In addition, PNN converges, always finding a solution in a short period of time with low computational cost. The insulation of two high voltage cables with different characteristics was analyzed. The test results allow us to conclude which wire has better insulation.
Use of energy analysis to evaluate the parameters of wave fields
Energy Technology Data Exchange (ETDEWEB)
Soldatov, V.N.; Sinitsyn, Ye.S.
1984-01-01
Algorithms are proposed and studied for energy analysis of the wave fields. A comparative evaluation is made of the resolution of the energy analysis methods. A method is examined for automated processing of the energograms allowing a search for an estimate of the parameters with significant acceleration of the computer calculations and saving of its working storage by designing multipurpose algorithms of data processing.
Auto-correlation analysis of wave heights in the Bay of Bengal
Indian Academy of Sciences (India)
Time series observations of significant wave heights in the Bay of Bengal were subjected to auto- correlation analysis to determine temporal variability scale. The analysis indicates an exponen- tial fall of auto-correlation in the first few hours with a decorrelation time scale of about six hours. A similar figure was found earlier ...
Melnick, Gary J.
1990-01-01
The Mission Operations and Data Analysis Plan is presented for the Submillimeter Wave Astronomy Satellite (SWAS) Project. It defines organizational responsibilities, discusses target selection and navigation, specifies instrument command and data requirements, defines data reduction and analysis hardware and software requirements, and discusses mission operations center staffing requirements.
Directory of Open Access Journals (Sweden)
Hyebin Lee
2018-02-01
Full Text Available Wind-wave hybrid power generation systems have the potential to become a significant source of affordable renewable energy. However, their strong interactions with both wind- and wave-induced forces raise a number of technical challenges for modelling. The present study undertakes a numerical investigation on multi-body hydrodynamic interaction between a wind-wave hybrid floating platform and multiple wave energy converters (WECs in a frequency domain. In addition to the exact responses of the platform and the WECs, the power take-off (PTO mechanism was taken into account for analysis. The coupled hydrodynamic coefficients and wave exciting forces were obtained from WAMIT, the 3D diffraction/radiation solver based on the boundary element method. The overall performance of the multiple WECs is presented and compared with the performance of a single isolated WEC. The analysis showed significant differences in the dynamic responses of the WECs when the multi-body interaction was considered. In addition, the PTO damping effect made a considerable difference to the responses of the WECs. However, the platform response was only minimally affected by PTO damping. With regard to energy capture, the interaction effect of the designed multiple WEC array layout is evaluated. The WEC array configuration showed both constructive and destructive effects in accordance with the incident wave frequency and direction.
Lyu, Chao; Pedersen, Helle A.; Paul, Anne; Zhao, Liang; Solarino, Stefano
2017-07-01
It remains challenging to obtain absolute shear wave velocities of heterogeneities of small lateral extension in the uppermost mantle. This study presents a cross-section of Vs across the strongly heterogeneous 3-D structure of the western European Alps, based on array analysis of data from 92 broad-band seismic stations from the CIFALPS experiment and from permanent networks in France and Italy. Half of the stations were located along a dense sublinear array. Using a combination of these stations and off-profile stations, fundamental-mode Rayleigh wave dispersion curves were calculated using a combined frequency-time beamforming approach. We calculated dispersion curves for seven arrays of approximately 100 km aperture and 14 arrays of approximately 50 km aperture, the latter with the aim of obtaining a 2-D vertical cross-section of Vs beneath the western Alps. The dispersion curves were inverted for Vs(z), with crustal interfaces imposed from a previous receiver function study. The array approach proved feasible, as Vs(z) from independent arrays vary smoothly across the profile length. Results from the seven large arrays show that the shear velocity of the upper mantle beneath the European plate is overall low compared to AK135 with the lowest velocities in the internal part of the western Alps, and higher velocities east of the Alps beneath the Po plain. The 2-D Vs model is coherent with (i) a ∼100 km thick eastward-dipping European lithosphere west of the Alps, (ii) very high velocities beneath the Po plain, coherent with the presence of the Alpine (European) slab and (iii) a narrow low-velocity anomaly beneath the core of the western Alps (from the Briançonnais to the Dora Maira massif), and approximately colocated with a similar anomaly observed in a recent teleseismic P-wave tomography. This intriguing anomaly is also supported by traveltime variations of subvertically propagating body waves from two teleseismic events that are approximately located on
An Overview of Recent Advances in the Iterative Analysis of Coupled Models for Wave Propagation
Directory of Open Access Journals (Sweden)
D. Soares
2014-01-01
Full Text Available Wave propagation problems can be solved using a variety of methods. However, in many cases, the joint use of different numerical procedures to model different parts of the problem may be advisable and strategies to perform the coupling between them must be developed. Many works have been published on this subject, addressing the case of electromagnetic, acoustic, or elastic waves and making use of different strategies to perform this coupling. Both direct and iterative approaches can be used, and they may exhibit specific advantages and disadvantages. This work focuses on the use of iterative coupling schemes for the analysis of wave propagation problems, presenting an overview of the application of iterative procedures to perform the coupling between different methods. Both frequency- and time-domain analyses are addressed, and problems involving acoustic, mechanical, and electromagnetic wave propagation problems are illustrated.
Jiang, Lijian; Efendiev, Yalchin; Ginting, Victor
2010-01-01
In this paper, we discuss a numerical multiscale approach for solving wave equations with heterogeneous coefficients. Our interest comes from geophysics applications and we assume that there is no scale separation with respect to spatial variables. To obtain the solution of these multiscale problems on a coarse grid, we compute global fields such that the solution smoothly depends on these fields. We present a Galerkin multiscale finite element method using the global information and provide a convergence analysis when applied to solve the wave equations. We investigate the relation between the smoothness of the global fields and convergence rates of the global Galerkin multiscale finite element method for the wave equations. Numerical examples demonstrate that the use of global information renders better accuracy for wave equations with heterogeneous coefficients than the local multiscale finite element method. © 2010 IMACS.
Wave propagation analysis of a size-dependent magneto-electro-elastic heterogeneous nanoplate
Ebrahimi, Farzad; Dabbagh, Ali; Reza Barati, Mohammad
2016-12-01
The analysis of the wave propagation behavior of a magneto-electro-elastic functionally graded (MEE-FG) nanoplate is carried out in the framework of a refined higher-order plate theory. In order to take into account the small-scale influence, the nonlocal elasticity theory of Eringen is employed. Furthermore, the material properties of the nanoplate are considered to be variable through the thickness based on the power-law form. Nonlocal governing equations of the MEE-FG nanoplate have been derived using Hamilton's principle. The results of the present study have been validated by comparing them with previous researches. An analytical solution of governing equations is performed to obtain wave frequencies, phase velocities and escape frequencies. The effect of different parameters, such as wave number, nonlocal parameter, gradient index, magnetic potential and electric voltage on the wave dispersion characteristics of MEE-FG nanoscale plates is studied in detail.
Jiang, Lijian
2010-08-01
In this paper, we discuss a numerical multiscale approach for solving wave equations with heterogeneous coefficients. Our interest comes from geophysics applications and we assume that there is no scale separation with respect to spatial variables. To obtain the solution of these multiscale problems on a coarse grid, we compute global fields such that the solution smoothly depends on these fields. We present a Galerkin multiscale finite element method using the global information and provide a convergence analysis when applied to solve the wave equations. We investigate the relation between the smoothness of the global fields and convergence rates of the global Galerkin multiscale finite element method for the wave equations. Numerical examples demonstrate that the use of global information renders better accuracy for wave equations with heterogeneous coefficients than the local multiscale finite element method. © 2010 IMACS.
Bispectral analysis of nonlinear compressional waves in a two-dimensional dusty plasma crystal
International Nuclear Information System (INIS)
Nosenko, V.; Goree, J.; Skiff, F.
2006-01-01
Bispectral analysis was used to study the nonlinear interaction of compressional waves in a two-dimensional strongly coupled dusty plasma. A monolayer of highly charged polymer microspheres was suspended in a plasma sheath. The microspheres interacted with a Yukawa potential and formed a triangular lattice. Two sinusoidal pump waves with different frequencies were excited in the lattice by pushing the particles with modulated Ar + laser beams. Coherent nonlinear interaction of the pump waves was shown to be the mechanism of generating waves at the sum, difference, and other combination frequencies. However, coherent nonlinear interaction was ruled out for certain combination frequencies, in particular, for the difference frequency below an excitation-power threshold, as predicted by theory
Directory of Open Access Journals (Sweden)
Keqin Yan
2017-01-01
Full Text Available This chapter presents a reliability study for an offshore jacket structure with emphasis on the features of nonconventional modeling. Firstly, a random set model is formulated for modeling the random waves in an ocean site. Then, a jacket structure is investigated in a pushover analysis to identify the critical wave direction and key structural elements. This is based on the ultimate base shear strength. The selected probabilistic models are adopted for the important structural members and the wave direction is specified in the weakest direction of the structure for a conservative safety analysis. The wave height model is processed in a P-box format when it is used in the numerical analysis. The models are applied to find the bounds of the failure probabilities for the jacket structure. The propagation of this wave model to the uncertainty in results is investigated in both an interval analysis and Monte Carlo simulation. The results are compared in context of information content and numerical accuracy. Further, the failure probability bounds are compared with the conventional probabilistic approach.
Study on crack scattering in aluminum plates with Lamb wave frequency–wavenumber analysis
International Nuclear Information System (INIS)
Yu, Lingyu; Tian, Zhenhua; Leckey, Cara A C
2013-01-01
The multimodal characteristic of Lamb waves makes the interpretation of Lamb wave signals difficult in either the time or frequency domain. In this work, we present our study of Lamb wave propagation characterization and crack scattering using frequency–wavenumber analysis. The aim is to investigate three dimensional (3D) Lamb wave behavior in the presence of crack damage via the application of frequency–wavenumber analysis. The analysis techniques are demonstrated using simulation examples of an aluminum plate with a through-thickness crack. Both in-plane and out-of-plane components are acquired through a 3D elastodynamic finite integration technique (EFIT), while the out-of-plane component is also experimentally obtained using a scanning laser Doppler vibrometer for verification purposes. The time–space wavefield is then transformed to the frequency–wavenumber domain by a two dimensional (2D) Fourier transform and the out-of-plane EFIT results are compared to experimental measurements. The experimental and simulated results are found to be in close agreement. The frequency–wavenumber representation of in-plane and out-of-plane components shows clear distinction among various Lamb wave modes that are present. However, spatial information is lost during this 2D transformation. A short space 2D Fourier transform is therefore adopted to obtain the frequency–wavenumber spectra at various spatial locations, resulting in a space–frequency–wavenumber representation of the signal. The space–frequency–wavenumber analysis has shown its potential for indicating crack presence. (paper)
Improved analysis of all-sky meteor radar measurements of gravity wave variances and momentum fluxes
Directory of Open Access Journals (Sweden)
V. F. Andrioli
2013-05-01
Full Text Available The advantages of using a composite day analysis for all-sky interferometric meteor radars when measuring mean winds and tides are widely known. On the other hand, problems arise if this technique is applied to Hocking's (2005 gravity wave analysis for all-sky meteor radars. In this paper we describe how a simple change in the procedure makes it possible to use a composite day in Hocking's analysis. Also, we explain how a modified composite day can be constructed to test its ability to measure gravity wave momentum fluxes. Test results for specified mean, tidal, and gravity wave fields, including tidal amplitudes and gravity wave momentum fluxes varying strongly with altitude and/or time, suggest that the modified composite day allows characterization of monthly mean profiles of the gravity wave momentum fluxes, with good accuracy at least at the altitudes where the meteor counts are large (from 89 to 92.5 km. In the present work we also show that the variances measured with Hocking's method are often contaminated by the tidal fields and suggest a method of empirical correction derived from a simple simulation model. The results presented here greatly increase our confidence because they show that our technique is able to remove the tide-induced false variances from Hocking's analysis.
Self-consistent adjoint analysis for topology optimization of electromagnetic waves
Deng, Yongbo; Korvink, Jan G.
2018-05-01
In topology optimization of electromagnetic waves, the Gâteaux differentiability of the conjugate operator to the complex field variable results in the complexity of the adjoint sensitivity, which evolves the original real-valued design variable to be complex during the iterative solution procedure. Therefore, the self-inconsistency of the adjoint sensitivity is presented. To enforce the self-consistency, the real part operator has been used to extract the real part of the sensitivity to keep the real-value property of the design variable. However, this enforced self-consistency can cause the problem that the derived structural topology has unreasonable dependence on the phase of the incident wave. To solve this problem, this article focuses on the self-consistent adjoint analysis of the topology optimization problems for electromagnetic waves. This self-consistent adjoint analysis is implemented by splitting the complex variables of the wave equations into the corresponding real parts and imaginary parts, sequentially substituting the split complex variables into the wave equations with deriving the coupled equations equivalent to the original wave equations, where the infinite free space is truncated by the perfectly matched layers. Then, the topology optimization problems of electromagnetic waves are transformed into the forms defined on real functional spaces instead of complex functional spaces; the adjoint analysis of the topology optimization problems is implemented on real functional spaces with removing the variational of the conjugate operator; the self-consistent adjoint sensitivity is derived, and the phase-dependence problem is avoided for the derived structural topology. Several numerical examples are implemented to demonstrate the robustness of the derived self-consistent adjoint analysis.
Pierce gain analysis for a sheet beam in a rippled waveguide traveling-wave tube
International Nuclear Information System (INIS)
Carlsten, Bruce E.
2001-01-01
A Pierce-type mode analysis is presented for a planar electron beam in a rippled planar waveguide. This analysis describes the gain of a traveling-wave tube consisting of that geometry. The dispersion relation is given by the determinant of a matrix based on the coupling of different free-space modes through the boundary conditions. For the case of high-frequency, low-power amplifiers, the dispersion relation reduces to a simple cubic expression for the Compton regime, leading to three roots analogous to the Pierce solution of a standard traveling-wave tube. The analysis shows that this type of traveling-wave tube is capable of very high gain at extremely high frequencies
A two-step FEM-SEM approach for wave propagation analysis in cable structures
Zhang, Songhan; Shen, Ruili; Wang, Tao; De Roeck, Guido; Lombaert, Geert
2018-02-01
Vibration-based methods are among the most widely studied in structural health monitoring (SHM). It is well known, however, that the low-order modes, characterizing the global dynamic behaviour of structures, are relatively insensitive to local damage. Such local damage may be easier to detect by methods based on wave propagation which involve local high frequency behaviour. The present work considers the numerical analysis of wave propagation in cables. A two-step approach is proposed which allows taking into account the cable sag and the distribution of the axial forces in the wave propagation analysis. In the first step, the static deformation and internal forces are obtained by the finite element method (FEM), taking into account geometric nonlinear effects. In the second step, the results from the static analysis are used to define the initial state of the dynamic analysis which is performed by means of the spectral element method (SEM). The use of the SEM in the second step of the analysis allows for a significant reduction in computational costs as compared to a FE analysis. This methodology is first verified by means of a full FE analysis for a single stretched cable. Next, simulations are made to study the effects of damage in a single stretched cable and a cable-supported truss. The results of the simulations show how damage significantly affects the high frequency response, confirming the potential of wave propagation based methods for SHM.
Directory of Open Access Journals (Sweden)
Peter Glen
Full Text Available There is no consensus as to what extent of "wrap" is required in a fundoplication for correction of gastroesophageal reflux disease (GERD.To evaluate if a complete (360 degree or partial fundoplication gives better control of GERD.A systematic search of MEDLINE and Scopus identified interventional and observational studies of fundoplication in children. Screening identified those comparing techniques. The primary outcome was recurrence of GERD following surgery. Dysphagia and complications were secondary outcomes of interest. Meta-analysis was performed when appropriate. Study quality was assessed using the Cochrane Risk of Bias Tool.2289 abstracts were screened, yielding 2 randomized controlled trials (RCTs and 12 retrospective cohort studies. The RCTs were pooled. There was no difference in surgical success between partial and complete fundoplication, OR 1.33 [0.67,2.66]. In the 12 cohort studies, 3 (25% used an objective assessment of the surgery, one of which showed improved outcomes with complete fundoplication. Twenty-five different complications were reported; common were dysphagia and gas-bloat syndrome. Overall study quality was poor.The comparison of partial fundoplication with complete fundoplication warrants further study. The evidence does not demonstrate superiority of one technique. The lack of high quality RCTs and the methodological heterogeneity of observational studies limits a powerful meta-analysis.
Analysis of chromosomal abnormalities: a study of partial exposure to X-rays
International Nuclear Information System (INIS)
Andrade, Aida M.G. de; Mendes, Mariana E.; Mendonça, Julyanne C.G.; Melo, Laís; Hwang, Suy; Santos, Neide; Lima, Fabiana F. de; Centro Regional de Ciências Nucleares; Universidade Federal de Pernambuco
2017-01-01
Biological dosimetry is used in case of supposed accidental overexposure. The most commonly used biomarkers for assessing the absorbed dose are unstable chromosomal abnormalities. In a case of a partial body exposure, the frequencies of those abnormalities varies according to the area of the exposed body and may be substantially different from a total exposure of the body with an identical dose. The present study aimed to evaluate the frequency of chromosomal changes simulating, with blood samples, partial (25%, 50%) and full body irradiation (100%) in X-ray beam. The irradiation was performed at Metrology Service (CRCN-NE / CNEN) with a bundle of 250kVp X-rays, resulting in the absorbed dose of 1.0 Gy. Prior to obtain the metaphases, irradiated blood was mixed with non-irradiated blood, and then the mitotic metaphases for the chromosomal analyzes were obtained by culturing lymphocytes and the slides were stained with 5% Giemsa. It was observed that there was an increase in dicentric frequency when the dose percentage increases in both subjects (0.024 and 0.049 in subject 1 and 0.016 and 0.038 in subject 2) after irradiation. The cellular distribution was 'contaminated' only at dose 25% of the first individual who had a prolongation of the distribution. The Qdr and Dolphin methods were used to estimate partial absorbed dose, but the Qdr method was not efficient and whereas the Dolphin method was efficient when the individual had a prolonged cell distribution. It is necessary to increase the number of observations to be sure of the observed behaviors. (author)
Analysis of chromosomal abnormalities: a study of partial exposure to X-rays
Energy Technology Data Exchange (ETDEWEB)
Andrade, Aida M.G. de; Mendes, Mariana E.; Mendonça, Julyanne C.G.; Melo, Laís; Hwang, Suy; Santos, Neide; Lima, Fabiana F. de, E-mail: aidamgandrade@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife (Brazil); Centro Regional de Ciências Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Universidade Federal de Pernambuco (UFPE),Recife (Brazil). Centro de Biociências. Departamento de Genética
2017-11-01
Biological dosimetry is used in case of supposed accidental overexposure. The most commonly used biomarkers for assessing the absorbed dose are unstable chromosomal abnormalities. In a case of a partial body exposure, the frequencies of those abnormalities varies according to the area of the exposed body and may be substantially different from a total exposure of the body with an identical dose. The present study aimed to evaluate the frequency of chromosomal changes simulating, with blood samples, partial (25%, 50%) and full body irradiation (100%) in X-ray beam. The irradiation was performed at Metrology Service (CRCN-NE / CNEN) with a bundle of 250kVp X-rays, resulting in the absorbed dose of 1.0 Gy. Prior to obtain the metaphases, irradiated blood was mixed with non-irradiated blood, and then the mitotic metaphases for the chromosomal analyzes were obtained by culturing lymphocytes and the slides were stained with 5% Giemsa. It was observed that there was an increase in dicentric frequency when the dose percentage increases in both subjects (0.024 and 0.049 in subject 1 and 0.016 and 0.038 in subject 2) after irradiation. The cellular distribution was 'contaminated' only at dose 25% of the first individual who had a prolongation of the distribution. The Qdr and Dolphin methods were used to estimate partial absorbed dose, but the Qdr method was not efficient and whereas the Dolphin method was efficient when the individual had a prolonged cell distribution. It is necessary to increase the number of observations to be sure of the observed behaviors. (author)
International Nuclear Information System (INIS)
Tan Yiqing; Wang Yase; Dai Hongxiu; Li Haitao; Deng Yi; Xiong Liqin
2011-01-01
Objective: To evaluate selective salpingo-catheterization recanalization therapy in treating partial fallopian tube obstruction through comparing its clinical effectiveness with that of non-interventional radiology methods. Methods: During the period from January 2008 to October 2010, a total of 186 infertility women with partial fallopian tube obstruction, which was confirmed with hysterosalpingography, were encountered in authors' hospital. This study protocol was approved by our hospital ethics committee, and informed consent was obtained from all patients. According of different treatment methods, 186 patients were divided into two groups. Patients (n=78) in group A received non-interventional radiology methods, including hydrotubation, enema, laparoscopy, physical therapy and traditional Chinese medication, while patients (n=108) in group B received selective salpingo-catheterization recanalization therapy. All 186 patients were followed up for more than six months. Close observation on the pregnancy incidence after different treatments and fallopian tube patency was carried out. The clinical findings were documented. The results were statistically analyzed by using paired 'x2' test. Results: Half a year after different procedures, in group A the pregnancy rate was 12.82% (n=10), and different degrees of fallopian tube obstruction were found in 31.58% patients. Whereas in group B, during the same period of observation, the pregnancy rate was 58.33% (n=63), and partial occlusion in cornual region was seen in one patient (0.47%). Significant difference in both pregnancy rate and fallopian tube occlusion rate existed between two groups (P<0.05). Conclusion: Because of its minimal invasiveness, high effectiveness and safety, the selective salpingography together with fallopian tube recanalization procedures are well accepted by the patients. The selective salpingo-catheterization recanalization therapy is superior to non-interventional radiology methods in
Zirari, M.; Abdellah El-Hadj, A.; Bacha, N.
2010-03-01
A finite element method is used to simulate the deposition of the thermal spray coating process. A set of governing equations is solving by a volume of fluid method. For the solidification phenomenon, we use the specific heat method (SHM). We begin by comparing the present model with experimental and numerical model available in the literature. In this study, completely molten or semi-molten aluminum particle impacts a H13 tool steel substrate is considered. Next we investigate the effect of inclination of impact of a partially molten particle on flat substrate. It was found that the melting state of the particle has great effects on the morphologies of the splat.
Water pollution and income relationships: A seemingly unrelated partially linear analysis
Pandit, Mahesh; Paudel, Krishna P.
2016-10-01
We used a seemingly unrelated partially linear model (SUPLM) to address a potential correlation between pollutants (nitrogen, phosphorous, dissolved oxygen and mercury) in an environmental Kuznets curve study. Simulation studies show that the SUPLM performs well to address potential correlation among pollutants. We find that the relationship between income and pollution follows an inverted U-shaped curve for nitrogen and dissolved oxygen and a cubic shaped curve for mercury. Model specification tests suggest that a SUPLM is better specified compared to a parametric model to study the income-pollution relationship. Results suggest a need to continually assess policy effectiveness of pollution reduction as income increases.
Directory of Open Access Journals (Sweden)
Bilčík Matúš
2018-03-01
Full Text Available Due to expansion of utilisation of photovoltaics in ordinary households, the question arises how this phenomenon affects the electric power of photovoltaic modules. The article deals with the electric power analysis of photovoltaic modules as a function of two very important factors. The first examined factor was partial shading, and the second factor was the intensity of reflected radiation. In order to determine the dependence of module power on the aforementioned parameters, a measurement system under laboratory conditions has been prepared. For identification of the reflected radiation effect on the power of the photovoltaic module, a series of measurements was performed on 7 different surfaces with the same radiation source. It is evident from obtained experimental result that the ratio of reflected irradiation on the solar module power is 1.29%. By simulation of partial shading of photovoltaic module, the decrease of 86.15% in its output power was identified.
Limit cycle analysis of nuclear coupled density wave oscillations
International Nuclear Information System (INIS)
Ward, M.E.
1985-01-01
An investigation of limit cycle behavior for the nuclear-coupled density wave oscillation (NCDWO) in a boiling water reactor (BWR) was performed. A simplified nonlinear model of BWR core behavior was developed using a two-region flow channel representation, coupled with a form of the point-kinetics equation. This model has been used to investigate the behavior of large amplitude NCDWO's through conventional time-integration solutions and through application of a direct relaxation-oscillation limit cycle solution in phase space. The numerical solutions demonstrate the potential for severe global power and flow oscillations in a BWR core at off-normal conditions, such as might occur during Anticipated Transients without Scram. Because of the many simplifying assumptions used, it is felt that the results should not be interpreted as an absolute prediction of core behavior, but as an indication of the potential for large oscillations and a demonstration of the corresponding limit cycle mechanisms. The oscillations in channel density drive the core power variations, and are reinforced by heat flux variations due to the changing fuel temperature. A global temperature increase occurs as energy is accumulated in the fuel, and limits the magnitude of the oscillations because as the average channel density decreases, the amplitude and duration of positive void reactivity at a given oscillation amplitude is lessened
Design and analysis of tubular permanent magnet linear wave generator.
Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng
2014-01-01
Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG) and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG.
Design and Analysis of Tubular Permanent Magnet Linear Wave Generator
Directory of Open Access Journals (Sweden)
Jikai Si
2014-01-01
Full Text Available Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG.
Quantum analysis of the direct measurement of light waves
International Nuclear Information System (INIS)
Saldanha, Pablo L
2014-01-01
In a beautiful experiment performed about a decade ago, Goulielmakis et al (2004 Science 305 1267–69) made a direct measurement of the electric field of light waves. However, they used a laser source to produce the light field, whose quantum state has a null expectation value for the electric field operator, so how was it possible to measure this electric field? Here we present a quantum treatment for the f:2f interferometer used to calibrate the carrier–envelope phase of the light pulses in the experiment. We show how the special nonlinear features of the f:2f interferometer can change the quantum state of the electromagnetic field inside the laser cavity to a state with a definite oscillating electric field, explaining how the ‘classical’ electromagnetic field emerges in the experiment. We discuss that this experiment was, to our knowledge, the first demonstration of an absolute coherent superposition of different photon number states in the optical regime. (paper)
Design and Analysis of Tubular Permanent Magnet Linear Wave Generator
Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng
2014-01-01
Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG) and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG. PMID:25050388
Veto analysis for gravitational wave burst signals in TAMA300 data using an ALF filter
International Nuclear Information System (INIS)
Akutsu, T; Ando, M; Kanda, N; Tatsumi, D; Telada, S; Miyoki, S; Ohashi, M
2006-01-01
Data taken by interferometers for gravitational waves include noises caused by instabilities of the interferometers. Veto analyses to remove false events caused by detectors are then necessary to detect real gravitational waves or to obtain a lower upper limit. In this paper, a veto analysis with an environmental monitor channel was implemented. We calculate the trigger rate of TAMA300 data and demonstrate the veto analysis using an alternative linear fit (ALF) filter. A threshold for the environmental monitor channel signals is set to be at 1% of the false dismissal rate. The result shows a 1/10-1/1000 reduction of trigger event rates
Qualitative Resting Coronary Pressure Wave Form Analysis to Predict Fractional Flow Reserve.
Matsumura, Mitsuaki; Maehara, Akiko; Johnson, Nils P; Fearon, William F; De Bruyne, Bernard; Oldroyd, Keith G; Pijls, Nico H J; Jenkins, Paul; Ali, Ziad A; Mintz, Gary S; Stone, Gregg W; Jeremias, Allen
2018-03-27
To evaluate the predictability of resting distal coronary pressure wave forms for fractional flow reserve (FFR). Resting coronary wave forms were qualitatively evaluated for the presence of (i) dicrotic notch; (ii) diastolic dipping; and (iii) ventricularization. In a development cohort (n=88) a scoring system was developed that was then applied to a validation cohort (n=428) using a multivariable linear regression model to predict FFR and receiver operating characteristics (ROC) to predict FFR ≤0.8. In the development cohort, all 3 qualitative parameters were independent predictors of FFR. However, in a multivariable linear regression model in the validation cohort, qualitative wave form analysis did not further improve the ability of resting distal coronary to aortic pressure ratio (Pd/Pa) (p=0.80) or instantaneous wave-free ratio (iFR) (p=0.26) to predict FFR. Using ROC, the area under the curve of resting Pd/Pa (0.86 versus 0.86, P=0.08) and iFR (0.86 versus 0.86, P=0.26) did not improve by adding qualitative analysis. Qualitative coronary wave form analysis showed moderate classification agreement in predicting FFR but did not add substantially to the resting pressure gradients Pd/Pa and iFR; however, when discrepancies between quantitative and qualitative analyses are observed, artifact or pressure drift should be considered.
Mudgil, Deepak; Barak, Sheweta; Khatkar, B S
2017-11-01
Effect of partially hydrolyzed guar gum (PHGG) level (1-5%), culture level (1.5-3.5%) and incubation time (4-8 h) on texture profile of yogurt was studied using response surface methodology. The fortification of partially hydrolyzed guar gum in yogurt decreased the firmness and gumminess while it increased the adhesiveness, cohesiveness and springiness of yogurt significantly at p < 0.01. The culture level did not affect the textural properties of yogurt significantly except gumminess whereas textural properties of yogurt were negatively correlated with incubation time. The coefficient of determination for hardness/hardness, adhesiveness, cohesiveness, springiness and gumminess were 0.9216, 0.9397, 0.8914, 0.8971 and 0.9156, respectively, which revealed that the models obtained were significant as coefficient of determination value was close to one. The optimum conditions obtained were PHGG level 3.37%, culture level 1.96% and incubation time 5.96 h which leads to preparation of yogurt with desired textural characteristics.
International Nuclear Information System (INIS)
Landoni, J.A.
1979-07-01
This program describes the analytical models for the CNTB computer program, which is permanently filed in the archive library of the General Atomic (GA) San Diego Data Center under reference number THSD-2699. Developed during the last four years, this computer program has been successfully applied in its presented form to the type of containment atmosphere transients illustrated in this report. For example, the CNTB computer program is applicable (1) to the design basis depressurization accident (DBDA) to determine the effect of the partial mixing on the containment atmospheric peak pressure (known as nonmixing penalty) and (2) for Class 9 accidents, such as the loss of forced circulation (LOFC), for the AIPA Phase I studies. The capability of the CNTB computer program has been substantially improved over its precursor, the CONTEMPT-G computer program, to predict the thermodynamic behavior of the containment atmosphere during helium releases, assuming partial mixing of the original air with the effluent and to predict the amount of the environmental leaks under closed and open containment conditions. In addition, the CNTB computer program running times are considerably below the ones required for the CONTEMPT-G computer program. Computational solution of the variable parameters in the containment atmosphere is effected by an iterative technique, while the temperatures for its boundaries are obtained by finite differences. The CNTB computer program, written in FORTRAN V, has been implemented at GA on the UNIVAC 1110 computer
International Nuclear Information System (INIS)
Muthuramalingam, M.; Manoharan, P.S.
2014-01-01
Highlights: • Analyzes the performance of ANN and ANFIS MPPT algorithms by stand alone PV system. • ISSBC with ANFIS can provide the overall efficiency higher than ANN. • CHBMLI integrate with SHE ANN modulation technique improve output voltage quality. • Simulation and hardware results show the ANFIS algorithm efficient than ANN algorithm. - Abstract: This paper presents a unique combination of an interleaved soft switched boost converter (ISSBC) run by a set of two photovoltaic panel (PV) with a distributed MPPT, suitable to guarantee MPPT even under partial shadowed conditions, managed by an adaptive neuro fuzzy inference system trained by the training data derived from a particle swarm optimization (PSO–ANFIS) unit. The ISSBC is followed by a, single phase cascaded H bridge five-level inverter (CHI) driven by the individual DC outputs of the ISSBC, with selective harmonic elimination scheme to eliminate typically the seventh order harmonics. A comparison of different intelligent distributed maximum power point tracking (MPPT) algorithms for photovoltaic (PV) system under partial shadow conditions is carried out. The use of the ISSBC guarantees mitigation of ripple and it is meant to handle higher currents with minimal switching losses. Simulation was carried out in the Matlab Simulink environment and an experimental verification with a scaled down model validated the proposed scheme. It has been thus established, by both simulation and experimental verification, that the PSO–ANFIS model of distributed MPPT scheme of control outperforms other schemes of control for MPPT
Analysis and Modeling of Parallel Photovoltaic Systems under Partial Shading Conditions
Buddala, Santhoshi Snigdha
Since the industrial revolution, fossil fuels like petroleum, coal, oil, natural gas and other non-renewable energy sources have been used as the primary energy source. The consumption of fossil fuels releases various harmful gases into the atmosphere as byproducts which are hazardous in nature and they tend to deplete the protective layers and affect the overall environmental balance. Also the fossil fuels are bounded resources of energy and rapid depletion of these sources of energy, have prompted the need to investigate alternate sources of energy called renewable energy. One such promising source of renewable energy is the solar/photovoltaic energy. This work focuses on investigating a new solar array architecture with solar cells connected in parallel configuration. By retaining the structural simplicity of the parallel architecture, a theoretical small signal model of the solar cell is proposed and modeled to analyze the variations in the module parameters when subjected to partial shading conditions. Simulations were run in SPICE to validate the model implemented in Matlab. The voltage limitations of the proposed architecture are addressed by adopting a simple dc-dc boost converter and evaluating the performance of the architecture in terms of efficiencies by comparing it with the traditional architectures. SPICE simulations are used to compare the architectures and identify the best one in terms of power conversion efficiency under partial shading conditions.
Recent Ultrasonic Guided Wave Inspection Development Efforts
International Nuclear Information System (INIS)
Rose, Joseph L.; Tittmann, Bernhard R.
2001-01-01
The recognition of such natural wave guides as plates, rods, hollow cylinders, multi-layer structures or simply an interface between two materials combined with an increased understanding of the physics and wave mechanics of guided wave propagation has led to a significant increase in the number of guided wave inspection applications being developed each year. Of primary attention Is the ability to inspect partially hidden structures, hard to access areas, and treated or insulated structures. An introduction to some physical consideration of guided waves followed by some sample problem descriptions in pipe, ice detection, fouling detection in the foods industry, aircraft, tar coated structures and acoustic microscopy is presented in this paper. A sample problem in Boundary Element Modeling is also presented to illustrate the move in guided wave analysis beyond detection and location analysis to quantification
Near-Field Ground Motion Modal versus Wave Propagation Analysis
Directory of Open Access Journals (Sweden)
Artur Cichowicz
2010-01-01
Full Text Available The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.
A Critical Analysis and Validation of the Accuracy of Wave Overtopping Prediction Formulae for OWECs
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David Gallach-Sánchez
2018-01-01
Full Text Available The development of wave energy devices is growing in recent years. One type of device is the overtopping wave energy converter (OWEC, for which the knowledge of the wave overtopping rates is a basic and crucial aspect in their design. In particular, the most interesting range to study is for OWECs with steep slopes to vertical walls, and with very small freeboards and zero freeboards where the overtopping rate is maximized, and which can be generalized as steep low-crested structures. Recently, wave overtopping prediction formulae have been published for this type of structures, although their accuracy has not been fully assessed, as the overtopping data available in this range is scarce. We performed a critical analysis of the overtopping prediction formulae for steep low-crested structures and the validation of the accuracy of these formulae, based on new overtopping data for steep low-crested structures obtained at Ghent University. This paper summarizes the existing knowledge about average wave overtopping, describes the physical model tests performed, analyses the results and compares them to existing prediction formulae. The new dataset extends the wave overtopping data towards vertical walls and zero freeboard structures. In general, the new dataset validated the more recent overtopping formulae focused on steep slopes with small freeboards, although the formulae are underpredicting the average overtopping rates for very small and zero relative crest freeboards.
Shock Mechanism Analysis and Simulation of High-Power Hydraulic Shock Wave Simulator
Directory of Open Access Journals (Sweden)
Xiaoqiu Xu
2017-01-01
Full Text Available The simulation of regular shock wave (e.g., half-sine can be achieved by the traditional rubber shock simulator, but the practical high-power shock wave characterized by steep prepeak and gentle postpeak is hard to be realized by the same. To tackle this disadvantage, a novel high-power hydraulic shock wave simulator based on the live firing muzzle shock principle was proposed in the current work. The influence of the typical shock characteristic parameters on the shock force wave was investigated via both theoretical deduction and software simulation. According to the obtained data compared with the results, in fact, it can be concluded that the developed hydraulic shock wave simulator can be applied to simulate the real condition of the shocking system. Further, the similarity evaluation of shock wave simulation was achieved based on the curvature distance, and the results stated that the simulation method was reasonable and the structural optimization based on software simulation is also beneficial to the increase of efficiency. Finally, the combination of theoretical analysis and simulation for the development of artillery recoil tester is a comprehensive approach in the design and structure optimization of the recoil system.
Analysis and Synthesis of WAVCIS Data for Characteristics of Waves and Currents on Louisiana Coast
Li, C.; Gibson, B.; Huang, W.; Luo, Y.; Milan, B.
2017-12-01
Texas-Louisiana coastal currents have been studied before, with a generally well-known pattern that is quasi steady except during the summer when it may weaken or reverse briefly. In the past decade, lot more efforts have been made and there is a large quantity of current velocity data accumulated. Among these data are those from the long-term mooring observations from the Wave Current-Surge Information System (WAVCIS), with a focus on the Louisiana coastal waters. More specifically, velocity and wave time series from current meters and pressure sensors or directional wave sensors at several locations on Louisiana coast provided unique opportunity to analyze and synthesize the characteristics of waves and currents on both east and west side of the Birdfoot Delta. In this study, we assembled all available WAVCIS data for a thorough analysis and synthesis of the characteristics of waves and coastal current in the area as a function of weather during different seasons. Year-to-year variabilities and seasonal variations are discussed. Spectrum, harmonic, and EOF analyses allowed a description and comparison of circulation patterns, wave and flow energy regimes, vertical shear of horizontal flows, tidal characteristics, synoptic weather effect, and severe weather impact. We provide basic statistics, as well as classifications of type of flows/circulations, and the major mechanisms that contribute to the variability.