WorldWideScience

Sample records for transmission-cavity resonance phenomena

  1. Resonance phenomena near thresholds

    International Nuclear Information System (INIS)

    Persson, E.; Mueller, M.; Rotter, I.; Technische Univ. Dresden

    1995-12-01

    The trapping effect is investigated close to the elastic threshold. The nucleus is described as an open quantum mechanical many-body system embedded in the continuum of decay channels. An ensemble of compound nucleus states with both discrete and resonance states is investigated in an energy-dependent formalism. It is shown that the discrete states can trap the resonance ones and also that the discrete states can directly influence the scattering cross section. (orig.)

  2. Nonlinear phenomena at cyclotron resonance

    International Nuclear Information System (INIS)

    Subbarao, D.; Uma, R.

    1986-01-01

    Finite amplitude electromagnetic waves in a magnetoplasma which typically occur in situations as in present day wave heating, current drives and other schemes in magnetically confined fusion systems, can show qualitatively different absorption and emission characteristics around resonant frequencies of the plasma because of anharmonicity. Linear wave plasma coupling as well as weak nonlinear effects such as parametric instabilities generally overlook this important effect even though the thresholds for the two phenomena as shown here are comparable. Though the effects described here are relevant to a host of nonlinear resonance effects in fusion plasmas, the authors mainly limit themselves to ECRH

  3. Simple classical approach to spin resonance phenomena

    DEFF Research Database (Denmark)

    Gordon, R A

    1977-01-01

    A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...

  4. Coherence Phenomena in Coupled Optical Resonators

    Science.gov (United States)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  5. Nuclear disarmament verification via resonant phenomena.

    Science.gov (United States)

    Hecla, Jake J; Danagoulian, Areg

    2018-03-28

    Nuclear disarmament treaties are not sufficient in and of themselves to neutralize the existential threat of the nuclear weapons. Technologies are necessary for verifying the authenticity of the nuclear warheads undergoing dismantlement before counting them toward a treaty partner's obligation. Here we present a concept that leverages isotope-specific nuclear resonance phenomena to authenticate a warhead's fissile components by comparing them to a previously authenticated template. All information is encrypted in the physical domain in a manner that amounts to a physical zero-knowledge proof system. Using Monte Carlo simulations, the system is shown to reveal no isotopic or geometric information about the weapon, while readily detecting hoaxing attempts. This nuclear technique can dramatically increase the reach and trustworthiness of future nuclear disarmament treaties.

  6. Condensed matter view of giant resonance phenomena

    International Nuclear Information System (INIS)

    Zangwill, A.

    1987-01-01

    The intent of this article is to present a view of giant resonance phenomena (an essentially atomic phenomenon) from the perspective of a condensed matter physicist with an interest in the optical properties of matter. As we shall see, this amounts to a particular prejudice about how one should think about many-body effects in a system of interacting electrons. Some of these effects are special to condensed matter systems and will be dealt with in the second half of this paper. However, it turns out that the authors view of the main ingredient to a giant resonance differs significantly from that normally taken by scientists trained in the traditional methods of atomic physics. Therefore, in the first section the author will take advantage of the fact that his contribution to this volume was composed and delivered to the publishers somewhat after the conclusion of the School (rather than before as requested by the organizers) and try to clearly distinguish the differences of opinion presented by the lecturers from the unalterable experimental facts. 46 references, 9 figures

  7. Half collision resonance phenomena in molecules

    International Nuclear Information System (INIS)

    Maximo Garcia-Sucre; Raseev, G.; Ross, S.C.

    1991-01-01

    The Escuela Latinoamericana de Fisica (ELAF) is a series of meeting s that for 28 years has played an important role in research-level teaching of physics in Latin America. This book contains the proceedings of ELAF 90 which was held at the Instituto Venezolano de Investigaciones Cientificas (IVIC) in Caracas, Venezuela from July 23 to August 3, 1990, as part of the commemoration of the 30th anniversary of IVIC. In contrast to previous ELAF's that were of general scope, ELAF 90 centered on a particular subject matter: '' Half Collisional Resonance Phenomena in Molecules, Experimental and Theoretical Approaches. ''The term ''Half Collision'' refers to the fragmentation of a molecular system following is excitation by light. The lack of an incident fragmentation of a molecular system following is excitation by light. The lack of an incident particle (other than the photon) in the fragmentation process is what leads to the term. The purpose of this volume is to present current results in the experimental and theoretical study of half collisions and also to include pedagogical papers at an introductory or intermediate level. The contributions are grouped into several sections; light sources; ionization; dissociation-experimental; dissociation-theory; competition between ionization and dissociation; and particle-molecule collisions

  8. Resonance phenomena at high level density

    International Nuclear Information System (INIS)

    Sobeslavsky, E.; Dittes, F.M.; Rotter, I.; Technische Univ. Dresden

    1994-11-01

    We investigate the behaviour of resonances as a function of the coupling strength between bound and unbound states on the basis of a simple S-matrix model. Resonance energies and widths are calculated for well isolated, overlapping and strongly overlapping resonance states. The formation of shorter and longer time scales (trapping effect) is traced. We illustrate that the cross section results from an interference of all resonance states in spite of the fact that their lifetimes may be very different. (orig.)

  9. Resonance Phenomena in Goupillaud-type Media

    Science.gov (United States)

    2010-10-01

    layered structures (7), anisotropic elastic bodies (8), anisotropic layered crystals (9, 10), elastic plates (11, 12), periodic media (13), laminated and...sandwich plates (14), composite laminates (15), piezoelectric composites (16), locally resonant acoustic metamaterials (17, 18), and acoustic wave...bm 2 c∑ k=1 ai,k cos (nθk) + bi,k sin (nθk) ] , (20) where operation ∗ means convolution , i = 1, 2, . . .m, and n ≥ 0. The stress representation

  10. The Friedrichs model and its use in resonance phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Gadella, M. [Departamento de Fisica Teorica, Atomica y Optica, Facultad de Ciencias, 47071 Valladolid (Spain); Pronko, G.P. [Institute for High Energy Physics, Protvino 142284, Moscow Region (Russian Federation)

    2011-09-15

    We present here a relation of different types of Friedrichs models and their use in the description and comprehension of resonance phenomena. We first discuss the basic Friedrichs model and obtain its resonance in the case that this is simple or doubly degenerated. Next, we discuss the model with N levels and show how the probability amplitude has an oscillatory behavior. Two generalizations of the Friedrichs model are suitable to introduce resonance behavior in quantum field theory. We also discuss a discrete version of the Friedrichs model and also a resonant interaction between two systems both with continuous spectrum. In an appendix, we review the mathematics of rigged Hilbert spaces. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Magnetic resonance phenomena in dynamics of relativistic particles

    International Nuclear Information System (INIS)

    Ternov, I.M.; Bordovitsyn, V.A.

    1987-01-01

    A relativistic generalization of Rabi's formula for magnetic resonance is given. On this basis, we consider fast and slow passage through resonance. We define a magnetic resonance exterior field as usual, using unit vectors of a Cartesian coordinate system, a homogeneous magnetic field, and the amplitude of a rotating magnetic field. For the description of spin dynamics we use the Bargmann-Michel-Telegdi equation

  12. Modern Theory of Gratings Resonant Scattering: Analysis Techniques and Phenomena

    CERN Document Server

    Sirenko, Yuriy K

    2010-01-01

    Diffraction gratings are one of the most popular objects of analysis in electromagnetic theory. The requirements of applied optics and microwave engineering lead to many new problems and challenges for the theory of diffraction gratings, which force us to search for new methods and tools for their resolution. In Modern Theory of Gratings, the authors present results of the electromagnetic theory of diffraction gratings that will constitute the base of further development of this theory, which meet the challenges provided by modern requirements of fundamental and applied science. This volume covers: spectral theory of gratings (Chapter 1) giving reliable grounds for physical analysis of space-frequency and space-time transformations of the electromagnetic field in open periodic resonators and waveguides; authentic analytic regularization procedures (Chapter 2) that, in contradistinction to the traditional frequency-domain approaches, fit perfectly for the analysis of resonant wave scattering processes; paramet...

  13. Tune Resonance Phenomena in the SPS and related Machine Protection

    CERN Document Server

    Baer, Tobias; Elsen, E

    2010-01-01

    The Super Proton Synchrotron (SPS) at CERN, with a peak energy of 450 GeV, is at the top of the LHC preaccelerator complex. SPS is at present the accelerator with the largest stored beam energy worldwide of up to 2.5 MJ. In 2008, a fast equipment failure led to an uncontrolled loss of a high intensity beam at an integer tune resonance, which resulted in major damage of a main dipole. Experimental studies and simulations provide clear understanding of the beam dynamics at different SPS tune resonances, that can lead to a complete beam loss in as little as 3 turns. Dedicated experiments of fast failures of the main power converters reveal that the current interlock systems are much too slow for an adequate machine protection. A new position interlock system, which is currently in the commissioning phase, will counteract the vulnerability of the SPS.

  14. Investigations of cavitation phenomena in pumps and pipes with resonance detectors

    International Nuclear Information System (INIS)

    Wesser, U.; Klockgethter, J.

    1977-01-01

    In fluid flows with high acoustic noise level resonance detectors are applied to measure cavitation phenomena for example in pumps. The analysis of the acoustic signals associated with the collapse of transient cavities leads to statistical parameters characterizing the cavitation state in the flow. The method is applicable even in the state of incipient cavitation. Some results for pumps and pipes are reported. (orig.) [de

  15. Searches for non-resonant new phenomena in final states with leptons and photons

    CERN Document Server

    Gonzalez Lopez, Oscar

    2017-01-01

    Some recent searches for hints of processes beyond the standard model performed by the CMS collaboration are presented. These focused on the detection of new phenomena more indirectly than the direct observation of a resonance indicating the presence of a new particle. No significant deviation from the standard model expectations have been observed and constraints for new physics have been set in several well-motivated scenarios.

  16. Stochastic Resonance-Like and Resonance Suppression-Like Phenomena in a Bistable System with Time Delay and Additive Noise

    International Nuclear Information System (INIS)

    Shu Chang-Zheng; Nie Lin-Ru; Zhou Zhong-Rao

    2012-01-01

    Stochastic resonance (SR)-like and resonance suppression (RS)-like phenomena in a time-delayed bistable system driven by additive white noise are investigated by means of stochastic simulations of the power spectrum, the quality factor of the power spectrum, and the mean first-passage time (MFPT) of the system. The calculative results indicate that: (i) as the system is driven by a small periodic signal, the quality factor as a function delay time exhibits a maximal value at smaller noise intensities, i.e., an SR-like phenomenon. With the increment in additive noise intensity, the extremum gradually disappears and the quality factor decreases monotonously with delay time. (ii) As the additive noise intensity is smaller, the curve of the MFPT with respect to delay time displays a peak, i.e., an RS-like phenomenon. At higher levels of noise, however, the non-monotonic behavior is lost. (general)

  17. Real-time magnetic resonance imaging of highly dynamic granular phenomena

    Science.gov (United States)

    Penn, Alexander; Pruessmann, Klaas P.; Müller, Christoph

    Probing non-intrusively the interior of three-dimensional granular systems is a challenging task for which a number of imaging techniques have been applied including positron emission particle tracking, X-ray tomography and magnetic resonance imaging (MRI). A particular advantage of MRI is its versatility allowing quantitative velocimetry through phase contrast encoding and tagging, arbitrary slice orientations and the flexibility to trade spatial for temporal resolution and vice versa during image reconstruction. However, previous attempts to image granular systems using MRI were often limited to (pseudo-) steady state systems due to the poor temporal resolution of conventional imaging methodology. Here we present an experimental approach that overcomes previous limitations in temporal resolution by implementing a variety of methodological advances, viz. parallel data acquisition through tailored multiple receiver coils, fast gradient readouts for time-efficient data sampling and engineered granular materials that contain signal sources of high proton density. Achieving a spatial and temporal resolution of, respectively, 2 mm x 2 mm and 50 ms, we were able to image highly dynamic phenomena in granular media such as bubble coalescence and granular compaction waves.

  18. Characterizing water fingering phenomena in soils using magnetic resonance imaging and multifractal theory

    Directory of Open Access Journals (Sweden)

    A. Posadas

    2009-02-01

    Full Text Available The study of water movement in soils is of fundamental importance in hydrologic science. It is generally accepted that in most soils, water and solutes flow through unsaturated zones via preferential paths or fingers. This paper combines magnetic resonance imaging (MRI with both fractal and multifractal theory to characterize preferential flow in three dimensions. A cubic double-layer column filled with fine and coarse textured sand was placed into a 500 gauss MRI system. Water infiltration through the column (0.15×0.15×0.15 m3 was recorded in steady state conditions. Twelve sections with a voxel volume of 0.1×0.1×10 mm3 each were obtained and characterized using fractal and multifractal theory. The MRI system provided a detailed description of the preferential flow under steady state conditions and was also useful in understanding the dynamics of the formation of the fingers. The f(α multifractal spectrum was very sensitive to the variation encountered at each horizontally-oriented slice of the column and provided a suitable characterization of the dynamics of the process identifying four spatial domains. In conclusion, MRI and fractal and multifractal analysis were able to characterize and describe the preferential flow process in soils. Used together, the two methods provide a good alternative to study flow transport phenomena in soils and in porous media.

  19. Liquid radiation detectors based on nano-silver surface plasmon resonance phenomena

    International Nuclear Information System (INIS)

    Puiso, J.; Laurikaitiene, J.; Adliene, D.; Prosycevas, I.

    2010-01-01

    The rapid development of micro- and nano-structures containing silver nano-particles is based on their unique physical properties. Despite the new applications of silver nano-particles in nano-medicine are under heavy discussions, silver nano-particles could be used in liquid radiation detectors thanks to the irradiation-induced surface plasmon resonance (SPR) phenomena observed in the colloidal solutions. Silver nitrate (1 mM AgNO 3 ) and sodium citrate (1 wt% and 5 wt% C 6 H 5 O 7 Na 3 ) were used as precursors for the fabrication of colloidal solutions. Prepared solutions were exposed to gamma-rays from a 60 Co gamma therapy unit 'Rokus-M' to varying absorbed doses, from 2 to 250 Gy. A UV/VIS/NIR spectrometer (Avantes-2048) was used for the measurement of the optical properties (absorbance) of the silver solutions. It was found that an initial absorbed dose of 2 Gy induced the formation of spherical silver nano-particles as it was indicated in the absorbance spectrum of the solution, which had a well-pronounced absorption maximum at the wavelength of 410 nm. There is a potential to measure absorbed doses down to around 20 mGy. The SPR peaks at the wavelengths of 500-700 nm were found at the highest investigated doses > 100 Gy, indicating the presence of silver nano-rods. The colour of colloidal solutions ranged from pale yellow to green and was dependent on the absorbed dose. The investigation has shown that density, size and shape of synthesised silver nano-particles are dependent on the absorbed dose and that shape transformations of the particles due to irradiation are possible. Application of colloidal solutions containing silver nano-particles for dosimetric purposes is discussed on the basis of the obtained results. (authors)

  20. Magneto-elastic resonant phenomena at the motion of the domain wall in weak ferromagnets

    International Nuclear Information System (INIS)

    Kuz'menko, A.P.; Zhukov, E.A.; Dobromyslov, M.B.; Kaminsky, A.V.

    2007-01-01

    Dynamics of domain walls (DWs) in transparent thin orthoferrite samples with weak ferromagnetic ordering is investigated at sub- and supersonic velocities. A resonant increase of Lamb waves and the formation of magnetoelastic solitons under resonant conditions in both an elastic and between a spin and elastic subsystems were observed

  1. Resonance phenomena in a time-dependent, three-dimensional model of an idealized eddy

    Science.gov (United States)

    Rypina, I. I.; Pratt, L. J.; Wang, P.; Äe; -zgökmen, T. M.; Mezic, I.

    2015-08-01

    We analyze the geometry of Lagrangian motion and material barriers in a time-dependent, three-dimensional, Ekman-driven, rotating cylinder flow, which serves as an idealization for an isolated oceanic eddy and other overturning cells with cylindrical geometry in the ocean and atmosphere. The flow is forced at the top through an oscillating upper lid, and the response depends on the frequency and amplitude of lid oscillations. In particular, the Lagrangian geometry changes near the resonant tori of the unforced flow, whose frequencies are rationally related to the forcing frequencies. Multi-scale analytical expansions are used to simplify the flow in the vicinity of resonant trajectories and to investigate the resonant flow geometries. The resonance condition and scaling can be motivated by simple physical argument. The theoretically predicted flow geometries near resonant trajectories have then been confirmed through numerical simulations in a phenomenological model and in a full solution of the Navier-Stokes equations.

  2. Giant resonance phenomena in the electron impact ionization of heavy atoms and ions

    International Nuclear Information System (INIS)

    Younger, S.M.

    1986-01-01

    Heavy atoms and ions offer an interesting opportunity to study atomic physics in a region where the atomic structure is dominated by the interelectronic interactions. One illustration of this is the profound term dependence of atomic orbitals for certain configurations of heavy atoms and ions. The appearance of giant scattering resonances in the cross sections for ionization of heavy atoms by electron impact is a manifestation of resonance behavior. Such resonant structures arise from the double well nature of the scattering potential and have recently been identified in the cross sections for the electron impact ionization of several xenon-like ions. The results of calculations showing effects for a variety of other ions are summarized. 7 refs., 4 figs

  3. Observation of Octupole Driven Resonance Phenomena with Space Charge at the CERN Proton Synchrotron

    CERN Document Server

    Métral, E; Martini, M; Steerenberg, R; Franchetti, Giuliano; Hofmann, I

    2006-01-01

    Several benchmarking space charge experiments have been performed during the last few years in the CERN Proton Synchrotron. These controlled experiments are of paramount importance to validate the present very powerful simulation codes. The observations of the combined effect of space charge and nonlinear resonance on beam loss and emittance, using a single controllable octupole during ~ 1 s at 1.4 GeV kinetic energy, are discussed in some detail in the present paper. By lowering the working point towards the octupolar resonance, a gradual transition from a regime of loss-free core emittance blow-up to a regime of continuous loss was found.

  4. The electronic conductance of polypyrrole (PPy molecular wires and emergence of Fano resonance phenomena

    Directory of Open Access Journals (Sweden)

    M Mardaani

    2012-06-01

    Full Text Available In this paper, we studied the electronic conductance of a polypyrrole polymer, which is embedded between two semi-infinite simple chains by using Green’s function technique in tight-binding approach. We first reduced the center polymer to a one dimensional chain with renormalized onsite and hopping energies by renormalization method. Then, we calculated the system conductivity as a function of incoming electron energy, polymer length and contact hopping terms. The results showed that by increasing polymer length and decreasing contact hopping energies, the conductance decreases in the gap regions. This means that for larger gaps, the electron tunneling happens with more difficulty. Moreover, at the resonance area, due to the existence of nitrogen atom in the polymer cyclic structure, the Fano resonance will emerge. Furthermore, the polymer can behave like a metallic chain by variation of the value of nitrogen on-site term.

  5. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Eiichiro; Nagashima, Nobuya (Ajinomoto Co. Inc., Kawasaki, Kanagawa (Japan))

    1982-09-01

    an automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a minicomputer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute (hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels (gelatin, alpha sub(sl)-casein), and (3) supercooling of capillary water in water-insoluble materials (zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized.

  6. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, E.; Nagashima, N.

    1982-01-01

    An automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a mini-computer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute(hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels(gelatin, J/sub s1/-casein), and (3) supercooling of capillary water in water-insoluble materials(zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized.

  7. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    International Nuclear Information System (INIS)

    Suzuki, Eiichiro; Nagashima, Nobuya

    1982-01-01

    an automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a minicomputer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute (hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels(gelatin, alpha sub(sl)-casein), and (3) supercooling of capillary water in water-insoluble materials(zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized. (author)

  8. Tune resonance phenomena in the SPS and machine protection via fast position interlocking

    CERN Document Server

    Baer, T; Bogey, T; Wenninger, J

    2010-01-01

    The Super Proton Synchrotron (SPS) at CERN with a peak energy of 450GeV is at the top of the LHC preaccelerator-complex. Apart from LHC, SPS is with Tevatron the accelerator with the largest stored beam energy, up to 2.5MJ. The SPS has a known vulnerability to fast equipment failures that led to an uncontrolled loss of a high intensity beam in 2008, which resulted in major damage of a main dipole. The beam loss was caused by a fast tune decrease towards an integer resonance. Simulations and distinct experimental studies provide clear understanding of the beam dynamics at different SPS tune resonances. Diverging closed orbit oscillations, dispersion explosion and abrupt increased beta-beating are the driving effects leading to a complete beam loss in as little as 3 turns (70us). Dedicated experiments of fast failures of the main power converters reveal that the current interlock systems are much too slow for an adequate machine protection. To counteract the vulnerability of the SPS, current research focuses on...

  9. Polarization phenomena in deuteron proton scattering: a useful tool for the study of nucleon resonances properties

    International Nuclear Information System (INIS)

    Rekalo, M.P.; Tomasi-Gustafsson, E.

    1996-01-01

    The microscopic structure of the nucleon N and its excited states N* can be determined through the (elastic or inelastic) electromagnetic form factors. These form factors should help to understand the nature of the transition regime from soft physics of the confinement region to the hard physics of the perturbative QCD. The authors show that hadron induced reactions with isospin zero projectiles, could be an effective method for the study of the nucleon structure, in particular through the measurement of polarization observables. They analyzed the properties of the inclusive d + p reactions, with particular interest in the domain of nucleonic resonances excitation. The calculated cross section and polarization observables show that it is possible to disentangle the different reaction mechanisms (omega, sigma and eta exchange) and bring new information about the electromagnetic form factors of the deuteron as well as of the nucleonic resonances. Existing data on the tensor analyzing power are in agreement with the prediction based on the omega exchange model. (authors)

  10. Electron spin resonance and quantum critical phenomena in VOx multiwall nanotubes

    International Nuclear Information System (INIS)

    Demishev, S.V.; Chernobrovkin, A.L.; Glushkov, V.V.; Samarin, N.A.; Sluchanko, N.E.; Semeno, A.V.; Goodilin, E.A.; Grigorieva, A.V.; Tretyakov, Yu.D.

    2008-01-01

    Basing on the high frequency (60 GHz) electron spin resonance study of the VO x multiwall nanotubes (VO x -NTs) carried out in the temperature range 4.2-200 K we report: (i) the first direct experimental evidence of the presence of the antiferromagnetic dimers in VO x -NTs and (ii) the observation of an anomalous low temperature growth of the magnetic susceptibility for quasi-free spins, which obey the power law χ(T)∝1/T α with the exponent α∼0.6 in a wide temperature range 4.2-50 K. We argue that the observed departures from the Curie-Weiss behaviour manifest the onset of the quantum critical regime and formation of the Griffiths phase as a magnetic ground state of these spin species. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Scaling effects in resonant coupling phenomena between fundamental and cladding modes in twisted microstructured optical fibers.

    Science.gov (United States)

    Napiorkowski, Maciej; Urbanczyk, Waclaw

    2018-04-30

    We show that in twisted microstructured optical fibers (MOFs) the coupling between the core and cladding modes can be obtained for helix pitch much greater than previously considered. We provide an analytical model describing scaling properties of the twisted MOFs, which relates coupling conditions to dimensionless ratios between the wavelength, the lattice pitch and the helix pitch of the twisted fiber. Furthermore, we verify our model using a rigorous numerical method based on the transformation optics formalism and study its limitations. The obtained results show that for appropriately designed twisted MOFs, distinct, high loss resonance peaks can be obtained in a broad wavelength range already for the fiber with 9 mm helix pitch, thus allowing for fabrication of coupling based devices using a less demanding method involving preform spinning.

  12. Experimental and Analytical Research on Resonance Phenomena of Vibrating Head with MRE Regulating Element

    Science.gov (United States)

    Miedzińska, D.; Gieleta, R.; Osiński, J.

    2015-02-01

    A vibratory pile hammer (VPH) is a mechanical device used to drive steel piles as well as tube piles into soil to provide foundation support for buildings or other structures. In order to increase the stability and the efficiency of the VPH work in the over-resonance frequency, a new VPH construction was developed at the Military University of Technology. The new VPH contains a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. This system is suspended in the static parts by the adaptive variable stiffness pillows based on a smart material, magnetorheological elastomer (MRE), whose rheological and mechanical properties can be reversibly and rapidly controlled by an external magnetic field. The work presented in the paper is a part of the modified VPH construction design process. It concerns the experimental research on the vibrations during the piling process and the analytical analyses of the gained signal. The results will be applied in the VPH control system.

  13. Generation of coherent radiation in vacuum ultra-violet by tripling frequency in continuous supersonic nitrogen free jet: quantitative investigation of resonance phenomena

    International Nuclear Information System (INIS)

    Faucher, Olivier

    1991-01-01

    This research thesis reports experimental studies performed on the generation of a coherent radiation in vacuum ultraviolet (94 nm) by tripling the frequency of an ultraviolet laser focussed within a continuous supersonic free nitrogen jet. After a recall of some general issues related to non-linear optics, the evolution of the non-linear susceptibility and conditions of phase adaptation in supersonic jet have been determined. This allowed a quantitative study of the third harmonic generation for the three following types of conversion: without resonance, with resonance with two photons, and with resonance with three photons. In the first two cases, due to the absence of saturation phenomena, measuring the harmonic signal intensity allows a diagnosis of the non-linear medium internal state to the performed. As far as the third harmonic generation with resonance with three photons is concerned, the use of supersonic free jet properties leads to a perfect understanding of saturation effects by self-absorption which are at the origin of the unusual character of the obtained spectra [fr

  14. Anomalous effect in Schumann resonance phenomena observed in Japan, possibly associated with the Chi-chi earthquake in Taiwan

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2005-06-01

    Full Text Available The Schumann resonance phenomenon has been monitored at Nakatsugawa (near Nagoya in Japan since the beginning of 1999, and due to the occurance of a severe earthquake (so-called Chi-chi earthquake on 21 September 1999 in Taiwan we have examined our Schumann resonance data at Nakatsugawa during the entire year of 1999. We have found a very anomalous effect in the Schumann resonance, possibly associated with two large land earthquakes (one is the Chi-chi earthquake and another one on 2 November 1999 (Chia-yi earthquake with a magnitude again greater than 6.0. Conspicuous effects are observed for the larger Chi-chi earthquake, so that we summarize the characteristics for this event. The anomaly is characterized mainly by the unusual increase in amplitude of the fourth Schumann resonance mode and a significant frequency shift of its peak frequency (~1.0Hz from the conventional value on the By magnetic field component which is sensitive to the waves propagating in the NS meridian plane. Anomalous Schumann resonance signals appeared from about one week to a few days before the main shock. Secondly, the goniometric estimation of the arrival angle of the anomalous signal is found to coincide with the Taiwan azimuth (the unresolved dual direction indicates toward South America. Also, the pulsed signals, such as the Q-bursts, were simultaneously observed with the "carrier" frequency around the peak frequency of the fourth Schumann resonance mode. The anomaly for the second event for the Chia-yi earthquake on 2 November had much in common. But, most likely due to a small magnitude, the anomaly appears one day before and lasts until one day after the main shock, with the enhancement at the fourth Schumann resonance mode being smaller in amplitude than the case of the Chi-chi earthquake. Yet, the other characteristics, including the goniometric direction finding result, frequency shift, etc., are nearly the same. Although the emphasis of the present study is

  15. Anomalous effect in Schumann resonance phenomena observed in Japan, possibly associated with the Chi-chi earthquake in Taiwan

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2005-06-01

    Full Text Available The Schumann resonance phenomenon has been monitored at Nakatsugawa (near Nagoya in Japan since the beginning of 1999, and due to the occurance of a severe earthquake (so-called Chi-chi earthquake on 21 September 1999 in Taiwan we have examined our Schumann resonance data at Nakatsugawa during the entire year of 1999. We have found a very anomalous effect in the Schumann resonance, possibly associated with two large land earthquakes (one is the Chi-chi earthquake and another one on 2 November 1999 (Chia-yi earthquake with a magnitude again greater than 6.0. Conspicuous effects are observed for the larger Chi-chi earthquake, so that we summarize the characteristics for this event. The anomaly is characterized mainly by the unusual increase in amplitude of the fourth Schumann resonance mode and a significant frequency shift of its peak frequency (~1.0Hz from the conventional value on the By magnetic field component which is sensitive to the waves propagating in the NS meridian plane. Anomalous Schumann resonance signals appeared from about one week to a few days before the main shock. Secondly, the goniometric estimation of the arrival angle of the anomalous signal is found to coincide with the Taiwan azimuth (the unresolved dual direction indicates toward South America. Also, the pulsed signals, such as the Q-bursts, were simultaneously observed with the "carrier" frequency around the peak frequency of the fourth Schumann resonance mode. The anomaly for the second event for the Chia-yi earthquake on 2 November had much in common. But, most likely due to a small magnitude, the anomaly appears one day before and lasts until one day after the main shock, with the enhancement at the fourth Schumann resonance mode being smaller in amplitude than the case of the Chi-chi earthquake. Yet, the other characteristics, including the goniometric direction finding result, frequency shift, etc., are nearly the same. Although the emphasis of

  16. Design of all-optical memory cell using EIT and lasing without inversion phenomena in optical micro ring resonators

    Science.gov (United States)

    Pasyar, N.; Yadipour, R.; Baghban, H.

    2017-07-01

    The proposed design of the optical memory unit cell contains dual micro ring resonators in which the effect of lasing without inversion (LWI) in three-level nano particles doped over the optical resonators or integrators as the gain segment is used for loss compensation. Also, an on/off phase shifter based on electromagnetically induced transparency (EIT) in three-level quantum dots (QDs) has been used for data reading at requested time. Device minimizing for integrated purposes and high speed data storage are the main advantages of the optical integrator based memory.

  17. Simultaneous EEG/fMRI analysis of the resonance phenomena in steady-state visual evoked responses.

    Science.gov (United States)

    Bayram, Ali; Bayraktaroglu, Zubeyir; Karahan, Esin; Erdogan, Basri; Bilgic, Basar; Ozker, Muge; Kasikci, Itir; Duru, Adil D; Ademoglu, Ahmet; Oztürk, Cengizhan; Arikan, Kemal; Tarhan, Nevzat; Demiralp, Tamer

    2011-04-01

    The stability of the steady-state visual evoked potentials (SSVEPs) across trials and subjects makes them a suitable tool for the investigation of the visual system. The reproducible pattern of the frequency characteristics of SSVEPs shows a global amplitude maximum around 10 Hz and additional local maxima around 20 and 40 Hz, which have been argued to represent resonant behavior of damped neuronal oscillators. Simultaneous electroencephalogram/functional magnetic resonance imaging (EEG/fMRI) measurement allows testing of the resonance hypothesis about the frequency-selective increases in SSVEP amplitudes in human subjects, because the total synaptic activity that is represented in the fMRI-Blood Oxygen Level Dependent (fMRI-BOLD) response would not increase but get synchronized at the resonance frequency. For this purpose, 40 healthy volunteers were visually stimulated with flickering light at systematically varying frequencies between 6 and 46 Hz, and the correlations between SSVEP amplitudes and the BOLD responses were computed. The SSVEP frequency characteristics of all subjects showed 3 frequency ranges with an amplitude maximum in each of them, which roughly correspond to alpha, beta and gamma bands of the EEG. The correlation maps between BOLD responses and SSVEP amplitude changes across the different stimulation frequencies within each frequency band showed no significant correlation in the alpha range, while significant correlations were obtained in the primary visual area for the beta and gamma bands. This non-linear relationship between the surface recorded SSVEP amplitudes and the BOLD responses of the visual cortex at stimulation frequencies around the alpha band supports the view that a resonance at the tuning frequency of the thalamo-cortical alpha oscillator in the visual system is responsible for the global amplitude maximum of the SSVEP around 10 Hz. Information gained from the SSVEP/fMRI analyses in the present study might be extrapolated to the

  18. Theory of threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2002-01-01

    Theory of Threshold Phenomena in Quantum Scattering is developed in terms of Reduced Scattering Matrix. Relationships of different types of threshold anomalies both to nuclear reaction mechanisms and to nuclear reaction models are established. Magnitude of threshold effect is related to spectroscopic factor of zero-energy neutron state. The Theory of Threshold Phenomena, based on Reduced Scattering Matrix, does establish relationships between different types of threshold effects and nuclear reaction mechanisms: the cusp and non-resonant potential scattering, s-wave threshold anomaly and compound nucleus resonant scattering, p-wave anomaly and quasi-resonant scattering. A threshold anomaly related to resonant or quasi resonant scattering is enhanced provided the neutron threshold state has large spectroscopic amplitude. The Theory contains, as limit cases, Cusp Theories and also results of different nuclear reactions models as Charge Exchange, Weak Coupling, Bohr and Hauser-Feshbach models. (author)

  19. Anomalous ELF phenomena in the Schumann resonance band as observed at Moshiri (Japan in possible association with an earthquake in Taiwan

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2008-12-01

    Full Text Available The ELF observation at Moshiri (geographic coordinates: 44.29° N, 142.21° E in Hokkaido, Japan, was used to find anomalous phenomena in the Schumann resonance band, possibly associated with a large earthquake (magnitude of 7.8 in Taiwan on 26 December 2006. The Schumann resonance signal (fundamental (n=1, 8 Hz; 2nd harmonic, 14 Hz, 3rd harmonic, 20 Hz, 4th, 26 Hz etc. is known to be supported by electromagnetic radiation from the global thunderstorms, and the anomaly in this paper is characterized by an increase in intensity at frequencies from the third to fourth Schumann resonance modes mainly in the BEW component with a minor corresponding increase in the BNS component also. Spectral modification takes place only in the interval of 21:00 UT±1 h, which corresponds to the global lightning activity concentrated in America. While distortions were absent in other lightning-active UT intervals, in particular, around 08:00 UT±1 h (Asian thunderstorms and around 15±1 h (African lightning activity. The anomaly occurred on 23 December three days prior to the main shock. The results observed were explained in terms of ELF radio wave perturbation caused by the lower ionospheric depression around the earthquake epicenter. The difference in the path lengths between the direct radio wave from an active global thunderstorm center and the wave scattered from the non-uniformity above Taiwan causes interference at higher resonance modes, which is successful in explaining the observational data.

  20. Paranormal phenomena

    Science.gov (United States)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  1. Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mukul M. Sharma; Steven L. Bryant; Carlos Torres-Verdin; George Hirasaki

    2007-09-30

    The petrophysical properties of rocks, particularly their relative permeability and wettability, strongly influence the efficiency and the time-scale of all hydrocarbon recovery processes. However, the quantitative relationships needed to account for the influence of wettability and pore structure on multi-phase flow are not yet available, largely due to the complexity of the phenomena controlling wettability and the difficulty of characterizing rock properties at the relevant length scales. This project brings together several advanced technologies to characterize pore structure and wettability. Grain-scale models are developed that help to better interpret the electric and dielectric response of rocks. These studies allow the computation of realistic configurations of two immiscible fluids as a function of wettability and geologic characteristics. These fluid configurations form a basis for predicting and explaining macroscopic behavior, including the relationship between relative permeability, wettability and laboratory and wireline log measurements of NMR and dielectric response. Dielectric and NMR measurements have been made show that the response of the rocks depends on the wetting and flow properties of the rock. The theoretical models can be used for a better interpretation and inversion of standard well logs to obtain accurate and reliable estimates of fluid saturation and of their producibility. The ultimate benefit of this combined theoretical/empirical approach for reservoir characterization is that rather than reproducing the behavior of any particular sample or set of samples, it can explain and predict trends in behavior that can be applied at a range of length scales, including correlation with wireline logs, seismic, and geologic units and strata. This approach can substantially enhance wireline log interpretation for reservoir characterization and provide better descriptions, at several scales, of crucial reservoir flow properties that govern oil

  2. Numerical simulation of possible resonance phenomena in the future eastern external dock of the harbour of Malaga

    International Nuclear Information System (INIS)

    Garcia Manes, M.; Martin Soldevilla, M. J.

    2009-01-01

    Resonant frequencies of the new recreational external eastern dock of the harbour of Malaga (Spain), have been analyzed with a Biuniqueness numerical model. The computational area includes an important part of the Malagueta beach, placed in front of the mouth of the future dock, and considered as a possible generation source of infra gravity energy. In order to determined all possible oscillations modes of the sheltered area, a previous simulation with a colour spectrum with equal energy into 25s - 1 to 350s - 1 frequency range, was carried out. the analysis of the response spectra gotten in the control points showed an important application at 70s - 1. the simulation with monochromatic wave of 70s period pointed out a second transversal oscillation mode among the Malagueta beach and the inner quay of the new dock. Additional numerical running using measured data coming from Malaga Spanish buoy network, placed near of the harbour, leads similar amplifications in the range of 70s 1 -80s - 1 close to that obtained theoretically. (Author) 3 refs

  3. Physics of Limiting Phenomena in Superconducting Microwave Resonators: Vortex Dissipation, Ultimate Quench and Quality Factor Degradation Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Checchin, Mattia [Illinois Inst. of Technology, Chicago, IL (United States)

    2016-12-01

    Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the

  4. Physics of limiting phenomena in superconducting microwave resonators: Vortex dissipation, ultimate quench and quality factor degradation mechanisms

    Science.gov (United States)

    Checchin, Mattia

    Superconducting niobium accelerating cavities are devices operating in radiofrequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associated to the superheating

  5. Switching Phenomena

    Science.gov (United States)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Mazza, M. G.; Kumar, P.; Plerou, V.; Preis, T.; Stokely, K.; Xu, L.

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines can suddenly "switch" from one behavior to another, even though they possess no perfect metronome in time. As if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many temporal patterns in physics, economics, and medicine and even begin to characterize the switching phenomena that enable a system to pass from one state to another. We discuss some applications of correlated randomness to understanding switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water's anomalies are related to a switching point (which is not unlike the "tipping point" immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not "outliers" (another Gladwell immortalization).

  6. Transport phenomena

    International Nuclear Information System (INIS)

    Kirczenow, G.; Marro, J.

    1974-01-01

    Some simple remarks on the basis of transport theory. - Entropy, dynamics and scattering theory. - Response, relaxation and fluctuation. - Fluctuating hydrodynamics and renormalization of susceptibilities and transport coefficients. - Irreversibility of the transport equations. - Ergodic theory and statistical mechanics. - Correlation functions in Heisenberg magnets. - On the Enskog hard-sphere kinetic eqquation and the transport phenomena of dense simple gases. - What can one learn from Lorentz models. - Conductivity in a magnetic field. - Transport properties in gases in presence of external fields. - Transport properties of dilute gases with internal structure. (orig.) [de

  7. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  8. Acoustic phenomena during boiling

    International Nuclear Information System (INIS)

    Dorofeev, B.M.

    1985-01-01

    Applied and theoretical significance of investigation into acoustic phenomena on boiling is discussed. Effect of spatial and time conditions on pressure vapour bubble has been elucidated. Collective effects were considered: acoustic interaction of bubbles, noise formation ion developed boiling, resonance and hydrodynamic autooscillations. Different methods for predicting heat transfer crisis using changes of accompanying noise characteristics were analysed. Principle peculiarities of generation mechanism of thermoacoustic autooscillations were analysed as well: formation of standing waves; change of two-phase medium contraction in a channel; relation of alternating pressure with boiling process as well as with instantaneous and local temperatures of heat transfer surface and liquid in a boundary layer

  9. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...

  10. Study of the dispersion phenomena connected with the absorption by recoilless nuclear resonance fluorescence; Etude des phenomenes de dispersion lies a l'absorption resonnante sans recul des noyaux atomiques

    Energy Technology Data Exchange (ETDEWEB)

    Imbert, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-12-01

    In nuclear resonance fluorescence as in the optical field abnormal dispersion curves are related to the absorption lines. It is possible, by using quadrupolar or magnetic splitting of the line in the case of recoilless resonance fluorescence (Moessbauer effect) to obtain differential dispersion effects between the two orthogonal linear or the two inverse circular components of the incident gamma radiation. These effects induce bi-refraction phenomena or Faraday rotation on the gamma beam, which have been studied on Fe-57 enriched absorbers. (author) [French] Comme dans le domaine optique, aux raies d'absorption de fluorescence resonnante des noyaux atomiques sont associees des courbes de dispersion anormale. Les decompositions des raies d'absorption de fluorescence resonnante sans recul (raies Moessbauer) par couplage quadrupolaire ou effet Zeeman permettent d'obtenir des effets dispersifs differentiels entre composantes lineaires orthogonales ou circulaires inverses du rayonnement gamma incident. Ces effets se traduisent par des phenomenes de birefringence ou de rotation Faraday, qui ont pu etre etudies sur des milieux enrichis en fer-57. (auteur)

  11. Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Michael Søgaard; Kornbeck, Kasper Pihl; Kristensen, Rune

    Dropout from university studies comprises a number of complex phenomena with serious complex consequences and profound political attention. Further analysis of the field is, therefore, warranted. Such an analysis is offered here as a systematic review which gives answers based on the best possible...... such dropout phenomena occur at universities? What can be done by the universities to prevent or reduce such dropout phenomena?...

  12. Resonance and Fractal Geometry

    NARCIS (Netherlands)

    Broer, Henk W.

    The phenomenon of resonance will be dealt with from the viewpoint of dynamical systems depending on parameters and their bifurcations. Resonance phenomena are associated to open subsets in the parameter space, while their complement corresponds to quasi-periodicity and chaos. The latter phenomena

  13. Fundamentals of Fire Phenomena

    DEFF Research Database (Denmark)

    Quintiere, James

    analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...

  14. Ultrashort Laser Pulse Phenomena

    CERN Document Server

    Diels, Jean-Claude

    2006-01-01

    Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

  15. Science and Paranormal Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Noyes, H. Pierre

    1999-06-03

    In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

  16. Nonequilibrium Phenomena in Plasmas

    CERN Document Server

    Sharma, A Surjalal

    2005-01-01

    The complexity of plasmas arises mainly from their inherent nonlinearity and far from equilibrium nature. The nonequilibrium behavior of plasmas is evident in the natural settings, for example, in the Earth's magnetosphere. Similarly, laboratory plasmas such as fusion bottles also have their fair share of complex behavior. Nonequilibrium phenomena are intimately connected with statistical dynamics and form one of the growing research areas in modern nonlinear physics. These studies encompass the ideas of self-organization, phase transition, critical phenomena, self-organized criticality and turbulence. This book presents studies of complexity in the context of nonequilibrium phenomena using theory, modeling, simulations, and experiments, both in the laboratory and in nature.

  17. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  18. Nonlinear resonances

    CERN Document Server

    Rajasekar, Shanmuganathan

    2016-01-01

    This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

  19. Interfacial transport phenomena

    CERN Document Server

    Slattery, John C; Oh, Eun-Suok

    2007-01-01

    Revised and updated extensively from the previous editionDiscusses transport phenomena at common lines or three-phase lines of contactProvides a comprehensive summary about the extensions of continuum mechanics to the nanoscale.

  20. Severe accident phenomena

    International Nuclear Information System (INIS)

    Jokiniemi, J.; Kilpi, K.; Lindholm, I.; Maekynen, J.; Pekkarinen, E.; Sairanen, R.; Silde, A.

    1995-02-01

    Severe accidents are nuclear reactor accidents in which the reactor core is substantially damaged. The report describes severe reactor accident phenomena and their significance for the safety of nuclear power plants. A comprehensive set of phenomena ranging from accident initiation to containment behaviour and containment integrity questions are covered. The report is based on expertise gained in the severe accident assessment projects conducted at the Technical Research Centre of Finland (VTT). (49 refs., 32 figs., 12 tabs.)

  1. Introduction to wetting phenomena

    International Nuclear Information System (INIS)

    Indekeu, J.O.

    1995-01-01

    In these lectures the field of wetting phenomena is introduced from the point of view of statistical physics. The phase transition from partial to complete wetting is discussed and examples of relevant experiments in binary liquid mixtures are given. Cahn's concept of critical-point wetting is examined in detail. Finally, a connection is drawn between wetting near bulk criticality and the universality classes of surface critical phenomena. (author)

  2. Magnetic Resonance Microscopy for Assessment of Morphological Changes in Hydrating Hydroxypropylmethylcellulose Matrix Tablets In Situ–Is it Possible to Detect Phenomena Related to Drug Dissolution Within the Hydrated Matrices?

    OpenAIRE

    Kulinowski, Piotr; Młynarczyk, Anna; Jasiński, Krzysztof; Talik, Przemysław; Gruwel, Marco L. H.; Tomanek, Bogusław; Węglarz, Władysław P.; Dorożyński, Przemysław

    2014-01-01

    ABSTRACT Purpose So far, the hydrated part of the HPMC matrix has commonly been denoted as a “gel” or “pseudogel” layer. No MRI-based results have been published regarding observation of internal phenomena related to drug dissolution inside swelling polymeric matrices during hydration. The purpose of the study was to detect such phenomena. Methods Multiparametric, spatially and temporally resolved T2 MR relaxometry, in situ, was applied to study formation of the hydration progress in HPMC mat...

  3. Ion exchange phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  4. SEPARATION PHENOMENA LOGISTIC REGRESSION

    Directory of Open Access Journals (Sweden)

    Ikaro Daniel de Carvalho Barreto

    2014-03-01

    Full Text Available This paper proposes an application of concepts about the maximum likelihood estimation of the binomial logistic regression model to the separation phenomena. It generates bias in the estimation and provides different interpretations of the estimates on the different statistical tests (Wald, Likelihood Ratio and Score and provides different estimates on the different iterative methods (Newton-Raphson and Fisher Score. It also presents an example that demonstrates the direct implications for the validation of the model and validation of variables, the implications for estimates of odds ratios and confidence intervals, generated from the Wald statistics. Furthermore, we present, briefly, the Firth correction to circumvent the phenomena of separation.

  5. Rheological phenomena in focus

    CERN Document Server

    Boger, DV

    1993-01-01

    More than possibly any other scientific discipline, rheology is easily visualized and the relevant literature contains many excellent photographs of unusual and often bizarre phenomena. The present book brings together these photographs for the first time. They are supported by a full explanatory text. Rheological Phenomena in Focus will be an indispensable support manual to all those who teach rheology or have to convince colleagues of the practical relevance of the subject within an industrial setting. For those who teach fluid mechanics, the book clearly illustrates the difference be

  6. Bioelectrochemistry II membrane phenomena

    CERN Document Server

    Blank, M

    1987-01-01

    This book contains the lectures of the second course devoted to bioelectro­ chemistry, held within the framework of the International School of Biophysics. In this course another very large field of bioelectrochemistry, i. e. the field of Membrane Phenomena, was considered, which itself consists of several different, but yet related subfields. Here again, it can be easily stated that it is impossible to give a complete and detailed picture of all membrane phenomena of biological interest in a short course of about one and half week. Therefore the same philosophy, as the one of the first course, was followed, to select a series of lectures at postgraduate level, giving a synthesis of several membrane phenomena chosen among the most'important ones. These lectures should show the large variety of membrane-regulated events occurring in living bodies, and serve as sound interdisciplinary basis to start a special­ ized study of biological phenomena, for which the investigation using the dual approach, physico-che...

  7. Sawtooth phenomena in tokamaks

    International Nuclear Information System (INIS)

    Kuvshinov, B.N.; Savrukhin, P.V.

    1989-01-01

    A review of experimental and theoretical investigaions of sawtooth phenomena in tokamaks is presented. Different types of sawtooth oscillations, scaling laws and methods of interanl disruption stabilization are described. Theoretical models of the sawtooth instability are discussed. 122 refs.; 4 tabs

  8. Fundamentals of wave phenomena

    CERN Document Server

    Hirose, Akira

    2010-01-01

    This textbook provides a unified treatment of waves that either occur naturally or can be excited and propagated in various media. This includes both longitudinal and transverse waves. The book covers both mechanical and electrical waves, which are normally covered separately due to their differences in physical phenomena.

  9. Chaotic phenomena in plasmas

    International Nuclear Information System (INIS)

    Kawai, Y.

    1991-08-01

    It has recently been recognized that the research on various aspects of chaotic dynamics grows rapidly as one of some areas in nonlinear science. On the other hands, the plasma has long been called a treasure-house of nonlinear phenomena, so it is easy to imagine that the plasma is abundant in chaotic phenomena. In fact, the research on plasma chaos is going on, such as the research on the stochastic magnetic field and the chaotic orbit in the toroidal helical system, as well as the research in other experiments. To review the present status of the research on plasma chaos and to make clear the basic common physics, a working group was organized in 1990 as a collaboration research of National Institute for Fusion Science. This is the report on its activity in 1990, with a stress on experimental data obtained in basic plasma experiments and RFP, and on the relaxed theories and computer simulations. (author)

  10. Wolf-Rayet phenomena

    International Nuclear Information System (INIS)

    Conti, P.S.

    1982-01-01

    The author reviews in broad terms the concept of Wolf-Rayet (W-R) phenomena, outlines what we currently know about the properties of stars showing such phenomena and indicates the directions in which future work is leading. He begins by listing the characteristics of W-R spectra and then considers the following specific problems: the absolute visual magnitudes; the heterogeneity of WN spectra; the existence of transition type spectra and compositions; the mass loss rates; the existence of very luminous and possibly very massive W-R stars. He discusses briefly our current understanding of the theoretical aspects of stellar evolution and stellar winds and the various scenarios that have been proposed to understand W-R stars. (Auth.)

  11. Transport phenomena II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena II covers forced convention, temperature distribution, free convection, diffusitivity and the mechanism of mass transfer, convective mass transfer, concentration

  12. Modelling of transport phenomena

    International Nuclear Information System (INIS)

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

    1993-09-01

    In this review article, we discuss key features of the transport phenomena and theoretical modelling to understand them. Experimental observations have revealed the nature of anomalous transport, i.e., the enhancement of the transport coefficients by the gradients of the plasma profiles, the pinch phenomena, the radial profile of the anomalous transport coefficients, the variation of the transport among the Bohm diffusion, Pseudo-classical confinement, L-mode and variety of improved confinement modes, and the sudden jumps such as L-H transition. Starting from the formalism of the transport matrix, the modelling based on the low frequency instabilities are reviewed. Theoretical results in the range of drift wave frequency are examined. Problems in theories based on the quasilinear and mixing-length estimates lead to the renewal of the turbulence theory, and the physics picture of the self-sustained turbulence is discussed. The theory of transport using the fluid equation of plasma is developed, showing that the new approach is very promising in explaining abovementioned characteristics of anomalous transport in both L-mode and improved confinement plasmas. The interference of the fluxes is the key to construct the physics basis of the bifurcation theory for the L-H transition. The present status of theories on the mechanisms of improved confinement is discussed. Modelling on the nonlocal nature of transport is briefly discussed. Finally, the impact of the anomalous transport on disruptive phenomena is also described. (author) 95 refs

  13. Large momentum transfer phenomena

    International Nuclear Information System (INIS)

    Imachi, Masahiro; Otsuki, Shoichiro; Matsuoka, Takeo; Sawada, Shoji.

    1978-01-01

    The large momentum transfer phenomena in hadron reaction drastically differ from small momentum transfer phenomena, and are described in this paper. Brief review on the features of the large transverse momentum transfer reactions is described in relation with two-body reactions, single particle productions, particle ratios, two jet structure, two particle correlations, jet production cross section, and the component of momentum perpendicular to the plane defined by the incident protons and the triggered pions and transverse momentum relative to jet axis. In case of two-body process, the exponent N of the power law of the differential cross section is a value between 10 to 11.5 in the large momentum transfer region. The breaks of the exponential behaviors into the power ones are observed at the large momentum transfer region. The break would enable to estimate the order of a critical length. The large momentum transfer phenomena strongly suggest an important role of constituents of hadrons in the hard region. Hard rearrangement of constituents from different initial hadrons induces large momentum transfer reactions. Several rules to count constituents in the hard region have been proposed so far to explain the power behavior. Scale invariant quark interaction and hard reactions are explained, and a summary of the possible types of hard subprocess is presented. (Kato, T.)

  14. Magnetic resonance microscopy for assessment of morphological changes in hydrating hydroxypropylmethylcellulose matrix tablets in situ-is it possible to detect phenomena related to drug dissolution within the hydrated matrices?

    Science.gov (United States)

    Kulinowski, Piotr; Młynarczyk, Anna; Jasiński, Krzysztof; Talik, Przemysław; Gruwel, Marco L H; Tomanek, Bogusław; Węglarz, Władysław P; Dorożyński, Przemysław

    2014-09-01

    So far, the hydrated part of the HPMC matrix has commonly been denoted as a "gel" or "pseudogel" layer. No MRI-based results have been published regarding observation of internal phenomena related to drug dissolution inside swelling polymeric matrices during hydration. The purpose of the study was to detect such phenomena. Multiparametric, spatially and temporally resolved T2 MR relaxometry, in situ, was applied to study formation of the hydration progress in HPMC matrix tablets loaded with L-dopa and ketoprofen using a 11.7 T MRI system. Two spin-echo based pulse sequences were used, one of them specifically designed to study short T2 signals. Two components in the T2 decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T2 values, were obtained. Based on the data, different region formation patterns (i.e. multilayer structure) were registered depending on drug presence and solubility. Inside the matrix with incorporated sparingly soluble drug a specific layer formation due to drug dissolution was detected, whereas a matrix with very slightly soluble drug does not form distinct external "gel-like" layer. We have introduced a new paradigm in the characterization of hydrating matrices using (1)H MRI methods. It reflects molecular mobility and concentration of water inside the hydrated matrix. For the first time, drug dissolution related phenomena, i.e. particular front and region formation, were observed by MRI methods.

  15. Modeling electrical dispersion phenomena in Earth materials

    Directory of Open Access Journals (Sweden)

    D. Patella

    2008-06-01

    Full Text Available It is illustrated that IP phenomena in rocks can be described using conductivity dispersion models deduced as solutions to a 2nd-order linear differential equation describing the motion of a charged particle immersed in an external electrical field. Five dispersion laws are discussed, namely: the non-resonant positive IP model, which leads to the classical Debye-type dispersion law and by extension to the Cole-Cole model, largely used in current practice; the non-resonant negative IP model, which allows negative chargeability values, known in metals at high frequencies, to be explained as an intrinsic physical property of earth materials in specific field cases; the resonant flat, positive or negative IP models, which can explain the presence of peak effects at specific frequencies superimposed on flat, positive or negative dispersion spectra.

  16. Quantification of natural phenomena

    International Nuclear Information System (INIS)

    Botero Alvarez, Javier

    1997-01-01

    The science is like a great spider's web in which unexpected connections appear and therefore it is frequently difficult to already know the consequences of new theories on those existent. The physics is a clear example of this. The Newton mechanics laws describe the physical phenomena observable accurately by means of our organs of the senses or by means of observation teams not very sophisticated. After their formulation at the beginning of the XVIII Century, these laws were recognized in the scientific world as a mathematical model of the nature. Together with the electrodynamics law, developed in the XIX century, and the thermodynamic one constitutes what we call the classic physics. The state of maturity of the classic physics at the end of last century it was such that some scientists believed that the physics was arriving to its end obtaining a complete description of the physical phenomena. The spider's web of the knowledge was supposed finished, or at least very near its termination. It ended up saying, in arrogant form, that if the initial conditions of the universe were known, we could determine the state of the same one in any future moment. Two phenomena related with the light would prove in firm form that mistaken that they were, creating unexpected connections in the great spider's web of the knowledge and knocking down part of her. The thermal radiation of the bodies and the fact that the light spreads to constant speed in the hole, without having an absolute system of reference with regard to which this speed is measured, they constituted the decisive factors in the construction of a new physics. The development of sophisticated of measure teams gave access to more precise information and it opened the microscopic world to the observation and confirmation of existent theories

  17. Magnetohydrodynamic flow phenomena

    International Nuclear Information System (INIS)

    Gerbeth, G.; Mutschke, G.; Eckert, S.

    1995-01-01

    The MHD group of the Institute of Safety Research performs basic studies on fluid dynamics and heat/mass transfer in fluids, particularly for electrically conducting fluids (liquid metals) exposed to external magnetic fields (Magnetohydrodynamics - MHD). Such a contactless influence on transport phenomena is of principal importance for a variety of applied problems including safety and design aspects in liquid metal cooled fusion reactors, fast reactors, and chemical systems. Any electrically conducting flow can be influenced without any contact by means of an external electromagnetic field. This, of course, can change the known hydromechanically flow patterns considerably. In the following two examples of such magnetic field influence are presented. (orig.)

  18. Random phenomena; Phenomenes aleatoires

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G. [Commissariat a l' energie atomique et aux energies alternatives - CEA, C.E.N.G., Service d' Electronique, Section d' Electronique, Grenoble (France)

    1963-07-01

    This document gathers a set of conferences presented in 1962. A first one proposes a mathematical introduction to the analysis of random phenomena. The second one presents an axiomatic of probability calculation. The third one proposes an overview of one-dimensional random variables. The fourth one addresses random pairs, and presents basic theorems regarding the algebra of mathematical expectations. The fifth conference discusses some probability laws: binomial distribution, the Poisson distribution, and the Laplace-Gauss distribution. The last one deals with the issues of stochastic convergence and asymptotic distributions.

  19. Transport phenomena I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena I includes viscosity, flow of Newtonian fluids, velocity distribution in laminar flow, velocity distributions with more than one independent variable, thermal con

  20. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  1. Phenomena Associated With EIT Waves

    Science.gov (United States)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.

    2003-01-01

    We discuss phenomena associated with "EIT Wave" transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to mfer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  2. Reduplication phenomena: body, mind and archetype.

    Science.gov (United States)

    Garner, J

    2000-09-01

    The many biological and few psychodynamic explanations of reduplicative syndromes tend to have paralleled the dualism of the phenomenon with organic theories concentrating on form and dynamic theories emphasising content. This paper extends the contribution of psychoanalytic thinking to an elucidation of the form of the delusion. Literature on clinical and aetiological aspects of reduplicative phenomena is reviewed alongside a brief examination of psychoanalytic models not overtly related to these phenomena. The human experience of doubles as universal archetype is considered. There is an obvious aetiological role for brain lesions in delusional misidentifications, but psychological symptoms in an individual can rarely be reduced to an organic disorder. The splitting and doubling which occurs in the phenomena have resonances in cultural mythology and in theories from different schools of psychodynamic thought. For the individual patient and doctor, it is a diverting but potentially empty debate to endeavour to draw strict divisions between what is physical and what is psychological although both need to be investigated. Nevertheless, in patients in whom there is clear evidence of an organic contribution to aetiology a psychodynamic understanding may serve to illuminate the patient's experience. Organic brain disease or serious functional illness predispose to regression to earlier modes of archetypical and primitive thinking with concretization of the metaphorical and mythological world. Psychoanalytic models have a contribution in describing the form as well as the content of reduplicative phenomena.

  3. Vacuum arc anode phenomena

    International Nuclear Information System (INIS)

    Miller, H.C.

    1976-01-01

    A brief review of anode phenomena in vacuum arcs is presented. Discussed in succession are: the transition of the arc into the anode spot mode; the temperature of the anode before, during and after the anode spot forms; and anode ions. Characteristically the anode spot has a temperature of the order of the atmospheric boiling point of the anode material and is a copious source of vapor and energetic ions. The dominant mechanism controlling the transition of the vacuum arc into the anode spot mode appears to depend upon the electrode geometry, the electrode material, and the current waveform of the particular vacuum arc being considered. Either magnetic constriction in the gap plasma or gross anode melting can trigger the transition; indeed, a combination of the two is a common cause of anode spot formation

  4. Foot morphometric phenomena.

    Science.gov (United States)

    Agić, Ante

    2007-06-01

    Knowledge of the foot morphometry is important for proper foot structure and function. Foot structure as a vital part of human body is important for many reasons. The foot anthropometric and morphology phenomena are analyzed together with hidden biomechanical descriptors in order to fully characterize foot functionality. For Croatian student population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot morphometric descriptors are influenced by many factors, such as life style, climate, and things of great importance in human society. Dominant descriptors related to fit and comfort are determined by the use 3D foot shape and advanced foot biomechanics. Some practical recommendations and conclusions for medical, sportswear and footwear practice are highlighted.

  5. Workshop on Interface Phenomena

    CERN Document Server

    Kreuzer, Hans

    1987-01-01

    This book contains the proceedings of the first Workshop on Interface Phenomena, organized jointly by the surface science groups at Dalhousie University and the University of Maine. It was our intention to concentrate on just three topics related to the kinetics of interface reactions which, in our opinion, were frequently obscured unnecessarily in the literature and whose fundamental nature warranted an extensive discussion to help clarify the issues, very much in the spirit of the Discussions of the Faraday Society. Each session (day) saw two principal speakers expounding the different views; the session chairmen were asked to summarize the ensuing discussions. To understand the complexity of interface reactions, paradigms must be formulated to provide a framework for the interpretation of experimen­ tal data and for the construction of theoretical models. Phenomenological approaches have been based on a small number of rate equations for the concentrations or mole numbers of the various species involved i...

  6. Fast fission phenomena

    International Nuclear Information System (INIS)

    Gregoire, Christian.

    1982-03-01

    Experimental studies of fast fission phenomena are presented. The paper is divided into three parts. In the first part, problems associated with fast fission processes are examined in terms of interaction potentials and a dynamic model is presented in which highly elastic collisions, the formation of compound nuclei and fast fission appear naturally. In the second part, a description is given of the experimental methods employed, the observations made and the preliminary interpretation of measurements suggesting the occurence of fast fission processes. In the third part, our dynamic model is incorporated in a general theory of the dissipative processes studied. This theory enables fluctuations associated with collective variables to be calculated. It is applied to highly inelastic collisions, to fast fission and to the fission dynamics of compound nuclei (for which a schematic representation is given). It is with these calculations that the main results of the second part can be interpreted [fr

  7. Nuclear fuel deformation phenomena

    International Nuclear Information System (INIS)

    Van Brutzel, L.; Dingreville, R.; Bartel, T.J.

    2015-01-01

    Nuclear fuel encounters severe thermomechanical environments. Its mechanical response is profoundly influenced by an underlying heterogeneous microstructure but also inherently dependent on the temperature and stress level histories. The ability to adequately simulate the response of such microstructures, to elucidate the associated macroscopic response in such extreme environments is crucial for predicting both performance and transient fuel mechanical responses. This chapter discusses key physical phenomena and the status of current modelling techniques to evaluate and predict fuel deformations: creep, swelling, cracking and pellet-clad interaction. This chapter only deals with nuclear fuel; deformations of cladding materials are discussed elsewhere. An obvious need for a multi-physics and multi-scale approach to develop a fundamental understanding of properties of complex nuclear fuel materials is presented. The development of such advanced multi-scale mechanistic frameworks should include either an explicit (domain decomposition, homogenisation, etc.) or implicit (scaling laws, hand-shaking,...) linkage between the different time and length scales involved, in order to accurately predict the fuel thermomechanical response for a wide range of operating conditions and fuel types (including Gen-IV and TRU). (authors)

  8. Arcjet cathode phenomena

    Science.gov (United States)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  9. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  10. Hysteresis phenomena in hydraulic measurement

    International Nuclear Information System (INIS)

    Ran, H J; Farhat, M; Luo, X W; Chen, Y L; Xu, H Y

    2012-01-01

    Hysteresis phenomena demonstrate the lag between the generation and the removal of some physical phenomena. This paper studies the hysteresis phenomena of the head-drop in a scaled model pump turbine using experiment test and CFD methods. These lag is induced by complicated flow patterns, which influenced the reliability of rotating machine. Keeping the same measurement procedure is concluded for the hydraulic machine measurement.

  11. Haters Phenomena in Social Media

    OpenAIRE

    Pradipta, Angga; Lailiyah, S.Sos, M.I.Kom, Nuriyatul

    2016-01-01

    Social media is internet-basic media, functioned as interaction media room based on multimedia technology. And social media created some effects. One of the negative effects of social media is haters phenomena. Haters are a person who easily said dirty words, harass, and humiliate to others. This phenomena causes anxiety—especially in Indonesia, even the Government issued public policy and letter of regulation about this phenomena, through Paragraph 27 verse (3) IT Constitution, Paragraph 45 ...

  12. Transport phenomena in environmental engineering

    Science.gov (United States)

    Sander, Aleksandra; Kardum, Jasna Prlić; Matijašić, Gordana; Žižek, Krunoslav

    2018-01-01

    A term transport phenomena arises as a second paradigm at the end of 1950s with high awareness that there was a strong need to improve the scoping of chemical engineering science. At that point, engineers became highly aware that it is extremely important to take step forward from pure empirical description and the concept of unit operations only to understand the specific process using phenomenological equations that rely on three elementary physical processes: momentum, energy and mass transport. This conceptual evolution of chemical engineering was first presented with a well-known book of R. Byron Bird, Warren E. Stewart and Edwin N. Lightfoot, Transport Phenomena, published in 1960 [1]. What transport phenomena are included in environmental engineering? It is hard to divide those phenomena through different engineering disciplines. The core is the same but the focus changes. Intention of the authors here is to present the transport phenomena that are omnipresent in treatment of various process streams. The focus in this chapter is made on the transport phenomena that permanently occur in mechanical macroprocesses of sedimentation and filtration for separation in solid-liquid particulate systems and on the phenomena of the flow through a fixed and a fluidized bed of particles that are immanent in separation processes in packed columns and in environmental catalysis. The fundamental phenomena for each thermal and equilibrium separation process technology are presented as well. Understanding and mathematical description of underlying transport phenomena result in scoping the separation processes in a way that ChEs should act worldwide.

  13. Toward Understanding Astrophysical Phenomena

    Science.gov (United States)

    Luan, Jing

    2015-06-01

    mass/angular momentum loss, which might cause e1 to grow rather than decay. Several pairs of solar system satellites occupy mean motion resonances (MMRs). We divide these into two groups according to their proximity to exact resonance. Proximity is measured by the existence of a separatrix in phase space. MMRs between Io-Europa, Europa-Ganymede and Enceladus-Dione are too distant from exact resonance for a separatrix to appear. A separatrix is present only in the phase spaces of the Mimas-Tethys and Titan-Hyperion MMRs and their resonant arguments are the only ones to exhibit substantial librations. When a separatrix is present, tidal damping of eccentricity or inclination excites overstable librations that can lead to passage through resonance on the damping timescale. However, after investigation, we conclude that the librations in the Mimas-Tethys and Titan-Hyperion MMRs are fossils and do not result from overstability. Rubble piles are common in the solar system. Monolithic elements touch their neighbors in small localized areas. Voids occupy a significant fraction of the volume. In a fluid-free environment, heat cannot conduct through voids; only radiation can transfer energy across them. We model the effective thermal conductivity of a rubble pile and show that it is proportional the square root of the pressure, P, for P ≤ epsilon 3Ymu where epsilonY is the material's yield strain and mu its shear modulus. Our model provides an excellent fit to the depth dependence of the thermal conductivity in the top 140cm of the lunar regolith. It also offers an explanation for the low thermal inertias of rocky asteroids and icy satellites. Lastly, we discuss how rubble piles slow down the cooling of small bodies such as asteroids. In this paper, we propose a computationally efficient time-domain algorithm capable of detecting gravitational waves (GWs) from coalescing binaries of compact objects with nearly zero time delay. In case when the signal is strong enough, our

  14. Algorithm of resonance orders for the objects

    Science.gov (United States)

    Zhang, YongGang; Zhang, JianXue

    2018-03-01

    In mechanical engineering, the object resonance phenomena often occur when the external incident wave frequency is close to object of the natural frequency. Object resonance phenomena get the maximum value when the external incident frequency is equal to object the natural frequency. Experiments found that resonance intension of the object is changed, different objects resonance phenomena present different characteristics of ladders. Based on object orders resonance characteristics, the calculation method of object orders resonance is put forward in the paper, and the application for the light and sound waves on the seven order resonance characteristics by people feel, the result error is less than 1%.Visible in this paper, the method has high accuracy and usability. The calculation method reveals that some object resonance occur present order characteristic only four types, namely the first-orders resonance characteristics, third-orders characteristics, five orders characteristic, and seven orders characteristic.

  15. Simulations of Biomechanical Phenomena

    Science.gov (United States)

    Gonzalez, Jose Cruz

    Recent studies have published breakthroughs in the application of finite element (FEA) studies in the design and analysis of advanced orthodontics. However, FEA has not captured bone remodeling responses to advanced orthodontics. The results of these simulations report unrealistic displacement around the nasal bridge, which impeded correlation with clinical data. Bone remodeling has been previously documented in FEA and has shown bone response to mechanical stimulus in femur bone models. However, the relationship between mechanical stimulus and bone remodeling has not been reported in orthodontic studies due to the complexity of the skull. In the current study, strain energy is used as the mechanical stimulus to control remodeling, from which density and modulus evolve. Due to the localization of forces in orthodontics, current remodeling algorithms have limited application. In turn, we developed an algorithm that dynamically collects, sorts, and bins stresses in all elements for regional remodeling based on the proximity of the element to the load. The results demonstrate that bone response to orthodontic appliances is different than that of an FEA without bone remodeling, due to load path changes based upon evolution of the bone properties. It was also found that density and moduli proximal to the load application site exhibit faster remodeling than those located remotely. Modeling another biomechanical phenomena, a 3D simulation was created to simulate recent experimental results that discovered a difference in impact mitigation properties of dense-polymer/foam bilayer structure based on the orientation of the dense-polymer with respect to the impact site. The impact energy transmitted varied in time of arrival and amplitude depending on the orientation of the structure (thin layer up or down). By creating a 3D explicit dynamic FEA simulation, it is expected to reduce costly experiments and time consumed in set up, and offer opportunities for optimization for

  16. Introductory lectures on critical phenomena

    International Nuclear Information System (INIS)

    Khajehpour, M.R.H.

    1988-09-01

    After a presentation of classical models for phase transitions and critical phenomena (Van der Waals theory, Weiss theory of ferromagnetism) and theoretical models (Ising model, XY model, Heisenberg model, spherical model) the Landau theory of critical and multicritical points and some single applications of renormalization group method in static critical phenomena are presented. 115 refs, figs and tabs

  17. Advanced diffusion processes and phenomena

    CERN Document Server

    Öchsner, Andreas; Belova, Irina

    2014-01-01

    This topical volume on Advanced Diffusion Processes and Phenomena addresses diffusion in a wider sense of not only mass diffusion but also heat diffusion in fluids and solids. Both diffusion phenomena play an important role in the characterization of engineering materials and corresponding structures. Understanding these different transport phenomena at many levels, from atomistic to macro, has therefore long attracted the attention of many researchers in materials science and engineering and related disciplines. The present topical volume captures a representative cross-section of some of the

  18. Kinetic effects on magnetohydrodynamic phenomena

    International Nuclear Information System (INIS)

    Naito, Hiroshi; Matsumoto, Taro

    2001-01-01

    Resistive and ideal magnetohydrodynamic (MHD) theories are insufficient to adequately explain MHD phenomena in the high-temperature plasma. Recent progress in numerical simulations concerning kinetic effects on magnetohydrodynamic phenomena is summarized. The following three topics are studied using various models treating extended-MHD phenomena. (1) Kinetic modifications of internal kink modes in tokamaks with normal and reversed magnetic shear configurations. (2) Temporal evolution of the toroidal Alfven eigenmode and fishbone mode in tokamaks with energetic ions. (3) Kinetic stabilization of a title mode in field-reversed configurations by means of anchoring ions and beam ions. (author)

  19. Micro transport phenomena during boiling

    CERN Document Server

    Peng, Xiaofeng

    2011-01-01

    "Micro Transport Phenomena During Boiling" reviews the new achievements and contributions in recent investigations at microscale. It presents some original research results and discusses topics at the frontier of thermal and fluid sciences.

  20. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos; Sun, Zhonghao

    2017-01-01

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration

  1. Renormalization group and critical phenomena

    International Nuclear Information System (INIS)

    Ji Qing

    2004-01-01

    The basic clue and the main steps of renormalization group method used for the description of critical phenomena is introduced. It is pointed out that this method really reflects the most important physical features of critical phenomena, i.e. self-similarity, and set up a practical solving method from it. This way of setting up a theory according to the features of the physical system is really a good lesson for today's physicists. (author)

  2. Containment severe accident thermohydraulic phenomena

    International Nuclear Information System (INIS)

    Frid, W.

    1991-08-01

    This report describes and discusses the containment accident progression and the important severe accident containment thermohydraulic phenomena. The overall objective of the report is to provide a rather detailed presentation of the present status of phenomenological knowledge, including an account of relevant experimental investigations and to discuss, to some extent, the modelling approach used in the MAAP 3.0 computer code. The MAAP code has been used in Sweden as the main tool in the analysis of severe accidents. The dependence of the containment accident progression and containment phenomena on the initial conditions, which in turn are heavily dependent on the in-vessel accident progression and phenomena as well as associated uncertainties, is emphasized. The report is in three parts dealing with: * Swedish reactor containments, the severe accident mitigation programme in Sweden and containment accident progression in Swedish PWRs and BWRs as predicted by the MAAP 3.0 code. * Key non-energetic ex-vessel phenomena (melt fragmentation in water, melt quenching and coolability, core-concrete interaction and high temperature in containment). * Early containment threats due to energetic events (hydrogen combustion, high pressure melt ejection and direct containment heating, and ex-vessel steam explosions). The report concludes that our understanding of the containment severe accident progression and phenomena has improved very significantly over the parts ten years and, thereby, our ability to assess containment threats, to quantify uncertainties, and to interpret the results of experiments and computer code calculations have also increased. (au)

  3. Teaching optical phenomena with Tracker

    Science.gov (United States)

    Rodrigues, M.; Simeão Carvalho, P.

    2014-11-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

  4. Critical Phenomena in Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Gundlach Carsten

    1999-01-01

    Full Text Available As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term 'critical phenomena'. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. This review gives an introduction to the phenomena, tries to summarize the essential features of what is happening, and then presents extensions and applications of this basic scenario. Critical phenomena are of interest particularly for creating surprising structure from simple equations, and for the light they throw on cosmic censorship and the generic dynamics of general relativity.

  5. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  6. Whistlers and related ionospheric phenomena

    CERN Document Server

    Helliwell, Robert A

    2006-01-01

    The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals.An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of

  7. Nonlinear resonance phenomena of a doped fibre laser under cavity ...

    Indian Academy of Sciences (India)

    quence and other routes to chaos, generalized multistability and crisis. But, doped ... of chaos and synchronization of coupled chaotic lasers (for communication with a ... The two basic issues in focus here for the nonlinear dynamical studies.

  8. Stochastic phenomena in a fiber Raman amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Kalashnikov, Vladimir [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Institute of Photonics, Vienna University of Technology (Austria); Sergeyev, Sergey V. [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Ania-Castanon, Juan Diego [Instituto de Optica CSIC, Madrid (Spain); Jacobsen, Gunnar [Acreo, Kista (Sweden); Popov, Sergei [Royal Institute of Technology (KTH), Stockholm (Sweden)

    2017-01-15

    The interplay of such cornerstones of modern nonlinear fiber optics as a nonlinearity, stochasticity and polarization leads to variety of the noise induced instabilities including polarization attraction and escape phenomena harnessing of which is a key to unlocking the fiber optic systems specifications required in high resolution spectroscopy, metrology, biomedicine and telecommunications. Here, by using direct stochastic modeling, the mapping of interplay of the Raman scattering-based nonlinearity, the random birefringence of a fiber, and the pump-to-signal intensity noise transfer has been done in terms of the fiber Raman amplifier parameters, namely polarization mode dispersion, the relative intensity noise of the pump laser, fiber length, and the signal power. The obtained results reveal conditions for emergence of the random birefringence-induced resonance-like enhancement of the gain fluctuations (stochastic anti-resonance) accompanied by pulse broadening and rare events in the form of low power output signals having probability heavily deviated from the Gaussian distribution. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Transport phenomena in particulate systems

    CERN Document Server

    Freire, José Teixeira; Ferreira, Maria do Carmo

    2012-01-01

    This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

  10. Discovery potential for new phenomena

    International Nuclear Information System (INIS)

    Godfrey, S.; Price, L.E.

    1997-03-01

    The authors examine the ability of future facilities to discover and interpret non-supersymmetric new phenomena. The authors first explore explicit manifestations of new physics, including extended gauge sectors, leptoquarks, exotic fermions, and technicolor models. They then take a more general approach where new physics only reveals itself through the existence of effective interactions at lower energy scales

  11. Strings, fields and critical phenomena

    International Nuclear Information System (INIS)

    Ambjoern, J.

    1987-07-01

    The connection between field theory and critical phenomena is reviewed. Emphasis is put on the use of Monte Carlo methods in the study of non-perturbative aspects of field theory. String theory is then described as a statistical theory of random surfaces and the critical behaviour is analyzed both by analytical and numerical methods. (orig.)

  12. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    Science.gov (United States)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  13. Studies of Novel Quantum Phenomena in Ruthenates

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Zhiqiang

    2011-04-08

    electron has been among central topics of contempary condensed matter physics. Ultrfast phase transitions accompanied by switching of conductivity or magnetization in stronly correlated materials are believed to be promising in developing next generation of transistors. Our work on layered ruthenates has remarkably advanced our understanding of how the exotic phenomena of correlated electrons is governed by the complex interplay between charge, spin, lattice and orbital degrees of freedom. In addition to studies on ruthenates, we have also expanded our research to the emerging field of Fe-based superconductors, focusing on the iron chalcogenide Fe1+y(Te1-xSex) superconductor system. We first studied the superconductivity of this alloy system following the discovery of superconductivity in FeSe using polycrystalline samples. Later, we successfuly grew high-quality single crystals of these materials. Using these single crystals, we have determined the magnetic structure of the parent compound Fe1+yTe, observed spin resonance of superconducting state in optimally doped samples, and established a phase diagram. Our work has produced an important impact in this burgeoning field. The PI presented an invited talk on this topic at APS March meeting in 2010. We have published 19 papers in these two areas (one in Nature materials, five in Physical Review Letters, and nine in Physical Review B) and submitted two (see the list of publications attached below).

  14. Transport phenomena in multiphase flows

    CERN Document Server

    Mauri, Roberto

    2015-01-01

    This textbook provides a thorough presentation of the phenomena related to the transport of mass, momentum and energy.  It lays all the basic physical principles, then for the more advanced readers, it offers an in-depth treatment with advanced mathematical derivations and ends with some useful applications of the models and equations in specific settings. The important idea behind the book is to unify all types of transport phenomena, describing them within a common framework in terms of cause and effect, respectively represented by the driving force and the flux of the transported quantity. The approach and presentation are original in that the book starts with a general description of transport processes, providing the macroscopic balance relations of fluid dynamics and heat and mass transfer, before diving into the mathematical realm of continuum mechanics to derive the microscopic governing equations at the microscopic level. The book is a modular teaching tool and can be used either for an introductory...

  15. Mathematical Modeling of Diverse Phenomena

    Science.gov (United States)

    Howard, J. C.

    1979-01-01

    Tensor calculus is applied to the formulation of mathematical models of diverse phenomena. Aeronautics, fluid dynamics, and cosmology are among the areas of application. The feasibility of combining tensor methods and computer capability to formulate problems is demonstrated. The techniques described are an attempt to simplify the formulation of mathematical models by reducing the modeling process to a series of routine operations, which can be performed either manually or by computer.

  16. Multiparticle phenomena and Landau damping

    International Nuclear Information System (INIS)

    Talman, R.

    1987-01-01

    The purpose of this paper is to survey various methods of studying multiparticle phenomena in accelerators. Both experimental and theoretical methods are described. An effort has been made to emphasize the intuitive and qualitative aspects rather than the detailed mathematics. Some of the terms or concepts to be explained are coherent and incoherent tunes, normal modes, Landau damping, beam-transfer functions, and feedback. These are all of daily importance in the interpretation of colliding-beam observations and the control of performance

  17. Antagonistic Phenomena in Network Dynamics

    Science.gov (United States)

    Motter, Adilson E.; Timme, Marc

    2018-03-01

    Recent research on the network modeling of complex systems has led to a convenient representation of numerous natural, social, and engineered systems that are now recognized as networks of interacting parts. Such systems can exhibit a wealth of phenomena that not only cannot be anticipated from merely examining their parts, as per the textbook definition of complexity, but also challenge intuition even when considered in the context of what is now known in network science. Here, we review the recent literature on two major classes of such phenomena that have far-reaching implications: (a) antagonistic responses to changes of states or parameters and (b) coexistence of seemingly incongruous behaviors or properties - both deriving from the collective and inherently decentralized nature of the dynamics. They include effects as diverse as negative compressibility in engineered materials, rescue interactions in biological networks, negative resistance in fluid networks, and the Braess paradox occurring across transport and supply networks. They also include remote synchronization, chimera states, and the converse of symmetry breaking in brain, power-grid, and oscillator networks as well as remote control in biological and bioinspired systems. By offering a unified view of these various scenarios, we suggest that they are representative of a yet broader class of unprecedented network phenomena that ought to be revealed and explained by future research.

  18. Quantum Proximity Resonances

    International Nuclear Information System (INIS)

    Heller, E.J.

    1996-01-01

    It is well known that at long wavelengths λ an s-wave scatterer can have a scattering cross section σ on the order of λ 2 , much larger than its physical size, as measured by the range of its potential. Very interesting phenomena can arise when two or more identical scatterers are placed close together, well within one wavelength. We show that, for a pair of identical scatterers, an extremely narrow p-wave open-quote open-quote proximity close-quote close-quote resonance develops from a broader s-wave resonance of the individual scatterers. A new s-wave resonance of the pair also appears. The relation of these proximity resonances (so called because they appear when the scatterers are close together) to the Thomas and Efimov effects is discussed. copyright 1996 The American Physical Society

  19. Luminous Phenomena - A Scientific Investigation of Anomalous Luminous Atmospheric Phenomena

    Science.gov (United States)

    Teodorani, M.

    2003-12-01

    Anomalous atmospheric luminous phenomena reoccur in several locations of Earth, in the form of multi-color light balls characterized by large dimensions, erratic motion, long duration and a correlated electromagnetic field. The author (an astrophysicist) of this book, which is organized as a selection of some of his technical and popularizing papers and seminars, describes and discusses all the efforts that have been done in 10 years, through several missions and a massive data analysis, in order to obtain some scientific explanation of this kind of anomalies, in particular the Hessdalen anomaly in Norway. The following topics are treated in the book: a) geographic archive of the areas of Earth where such phenomena are known to reoccur most often; b) observational techniques of astrophysical kind that have been used to acquire the data; c) main scientific results obtained so far; d) physical interpretation and natural hypothesis vs. ETV hypothesis; e) historical and chronological issues; f) the importance to brindle new energy sources; g) the importance to keep distance from any kind of "ufology". An unpublished chapter is entirely devoted to a detailed scientific investigation project of light phenomena reoccurring on the Ontario lake; the chosen new-generation multi-wavelength sensing instrumentation that is planned to be used in future missions in that specific area, is described together with scientific rationale and planned procedures. The main results, which were obtained in other areas of the world, such as the Arizona desert, USA and the Sibillini Mountains, Italy, are also briefly mentioned. One chapter is entirely dedicated to the presentation of extensive abstracts of technical papers by the author concerning this specific subject. The book is accompanied with a rich source of bibliographic references.

  20. Correlated randomness and switching phenomena

    Science.gov (United States)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Kumar, P.; Plerou, V.; Preis, T.

    2010-08-01

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines have no perfect metronome in time and no perfect spatial architecture-crystalline or otherwise. Nonetheless, as if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time and remarkably fine-tuned structures in space. Further, many of these processes and structures have the remarkable feature of “switching” from one behavior to another as if by magic. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many spatial and temporal patterns in biology, medicine, and economics and even begin to characterize the switching phenomena that enables a system to pass from one state to another. Inspired by principles developed by A. Nihat Berker and scores of other statistical physicists in recent years, we discuss some applications of correlated randomness to understand switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water’s anomalies are related to a switching point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not “outliers” (another Gladwell immortalization). Though more speculative, we support the idea of disease as arising from some kind of yet-to-be-understood complex switching phenomenon, by discussing data on selected examples, including heart disease and Alzheimer disease.

  1. Phenomena and Diosignes of Aratous

    Science.gov (United States)

    Avgoloupis, S. I.

    2013-01-01

    Aratous (305-240B.C.) was a singular intellectual, writer and poet which engage himself to compose a very interesting astronomical poet, using the "Dactylous sixstage' style, the formal style of the ancient Greek Epic poetry. This astronomic poem of Aratous "Phenomena and Diosignes" became very favorite reading during the Alexandrine, the Romman and the Byzandin eras as well and had received many praises from significant poets and particularly from Hipparchous and from Theonas from Alexandria, an astronomer of 4rth century A.C.(in Greeks)

  2. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2001-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. It has moved into a central place in condensed matter studies.Statistical physics, and more specifically, the theory of transitions between states of matter, more or less defines what we know about 'everyday' matter and its transformations.The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable in

  3. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2000-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. No longer an area of specialist interest, it has acquired a central focus in condensed matter studies. The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable information on important recent developments.The two review articles in this volume complement each other in a remarkable way. Both deal with what m

  4. Nonlinear phenomena in general relativity

    Science.gov (United States)

    Allahyari, Alireza; Firouzjaee, Javad T.; Mansouri, Reza

    2018-04-01

    The perturbation theory plays an important role in studying structure formation in cosmology and post-Newtonian physics, but not all phenomena can be described by the linear perturbation theory. Thus, it is necessary to study exact solutions or higher-order perturbations. Specifically, we study black hole (apparent) horizons and the cosmological event horizon formation in the perturbation theory. We emphasize that in the perturbative regime of the gravitational potential these horizons cannot form in the lower order. Studying the infinite plane metric, we show that, to capture the cosmological constant effect, we need at least a second-order expansion.

  5. Violent phenomena in the Universe

    CERN Document Server

    Narlikar, Jayant V

    2007-01-01

    The serenity of a clear night sky belies the evidence-gathered by balloons, rockets, satellites, and telescopes-that the universe contains centers of furious activity that pour out vast amounts of energy, some in regular cycles and some in gigantic bursts. This reader-friendly book, acclaimed by Nature as ""excellent and uncompromising,"" traces the development of modern astrophysics and its explanations of these startling celestial fireworks.This lively narrative ranges from the gravitational theories of Newton and Einstein to recent exciting discoveries of such violent phenomena as supernova

  6. Nonlinear Dynamic Phenomena in Mechanics

    CERN Document Server

    Warminski, Jerzy; Cartmell, Matthew P

    2012-01-01

    Nonlinear phenomena should play a crucial role in the design and control of engineering systems and structures as they can drastically change the prevailing dynamical responses. This book covers theoretical and applications-based problems of nonlinear dynamics concerned with both discrete and continuous systems of interest in civil and mechanical engineering. They include pendulum-like systems, slender footbridges, shape memory alloys, sagged elastic cables and non-smooth problems. Pendulums can be used as a dynamic absorber mounted in high buildings, bridges or chimneys. Geometrical nonlinear

  7. Quantum theory of collective phenomena

    CERN Document Server

    Sewell, G L

    2014-01-01

    ""An excellent and competent introduction to the field … [and] … a source of information for the expert."" - Physics Today""This a book of major importance…. I trust that this book will be used as a basis for the teaching of a balanced, modern and rigorous course on statistical mechanics in all universities."" - Bulletin of the London Mathematical Society""This is one of the best introductions to the subject, and it is strongly recommended to anyone interested in collective phenomena."" - Physics Bulletin ""The book may be recommended for students as a well-balanced introduction to this rich s

  8. Foot anthropometry and morphology phenomena.

    Science.gov (United States)

    Agić, Ante; Nikolić, Vasilije; Mijović, Budimir

    2006-12-01

    Foot structure description is important for many reasons. The foot anthropometric morphology phenomena are analyzed together with hidden biomechanical functionality in order to fully characterize foot structure and function. For younger Croatian population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot structure descriptors are influenced by many factors, as a style of life, race, climate, and things of the great importance in human society. Dominant descriptors are determined by principal component analysis. Some practical recommendation and conclusion for medical, sportswear and footwear practice are highlighted.

  9. Gravitational Anomaly and Transport Phenomena

    International Nuclear Information System (INIS)

    Landsteiner, Karl; Megias, Eugenio; Pena-Benitez, Francisco

    2011-01-01

    Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficient. The gravitational anomaly gives rise to an anomalous vortical effect even for an uncharged fluid.

  10. Quantum phenomena in gravitational field

    Science.gov (United States)

    Bourdel, Th.; Doser, M.; Ernest, A. D.; Voronin, A. Yu.; Voronin, V. V.

    2011-10-01

    The subjects presented here are very different. Their common feature is that they all involve quantum phenomena in a gravitational field: gravitational quantum states of ultracold antihydrogen above a material surface and measuring a gravitational interaction of antihydrogen in AEGIS, a quantum trampoline for ultracold atoms, and a hypothesis on naturally occurring gravitational quantum states, an Eötvös-type experiment with cold neutrons and others. Considering them together, however, we could learn that they have many common points both in physics and in methodology.

  11. Quantum phenomena in gravitational field

    International Nuclear Information System (INIS)

    Bourdel, Th.; Doser, M.; Ernest, A.D.; Voronin, A.Y.; Voronin, V.V.

    2010-01-01

    The subjects presented here are very different. Their common feature is that they all involve quantum phenomena in a gravitational field: gravitational quantum states of ultracold anti-hydrogen above a material surface and measuring a gravitational interaction of anti-hydrogen in AEGIS, a quantum trampoline for ultracold atoms, and a hypothesis on naturally occurring gravitational quantum states, an Eoetvoes-type experiment with cold neutrons and others. Considering them together, however, we could learn that they have many common points both in physics and in methodology. (authors)

  12. Radiation phenomena of plasma waves, 1

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro.

    1978-06-01

    The fundamental radiation theories on radiation phenomena of plasma waves are presented. As the fundamental concepts of propagating waves, phase, group and ray velocities are explained, and phase velocity surface, group velocity surface, ray velocity surface and refractive index surface are considered. These concepts are important in anisotropic plasma. Fundamental equations for electron plasma waves in a fluid model and fundamental equations for ion plasma waves can be expressed with the above mentioned concepts. Kuehl derived the formulas for general radiation fields of electromagnetic and electrostatic waves which are radiated from an arbitrary current source. Fundamental equations for kinetic model are the Vlasov equation and Maxwell equations. By investigating electromagnetic radiation in cold anisotropic plasma, Kuehl found the important behavior that the fields radiated from a source become very large in certain directions for some ranges of plasma parameters. The fact is the so-called high frequency resonance cone. A fundamental formula for quasi-static radiation from an oscillating point source in warm anisotropic plasma includes the near field of electromagnetic mode and the field of electrostatic mode, which are radiated from the source. This paper presents the formula in a generalized form. (Kato, T.)

  13. Macroscopic quantum systems and gravitational phenomena

    International Nuclear Information System (INIS)

    Pikovski, I.

    2014-01-01

    Low-energy quantum systems are studied theoretically in light of possible experiments to test the interplay between quantum theory and general relativity. The research focus in this thesis is on quantum systems which can be controlled with very high precision and which allow for tests of quantum theory at novel scales in terms of mass and size. The pulsed regime of opto-mechanics is explored and it is shown how short optical pulses can be used to prepare and characterize quantum states of a massive mechanical resonator, and how some phenomenological models of quantum gravity can be probed. In addition, quantum interferometry with photons and matter-waves in the presence of gravitational time dilation is considered. It is shown that time dilation causes entanglement between internal states and the center-of-mass position and that it leads to decoherence of all composite quantum systems. The results of the thesis show that the interplay between quantum theory and general relativity affects even low-energy quantum systems and that it offers novel phenomena which can be probed in experiments. (author) [de

  14. Multiple photon resonances

    International Nuclear Information System (INIS)

    Elliott, C.J.; Feldman, B.J.

    1979-02-01

    A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

  15. Natural phenomena hazards, Hanford Site, Washington

    International Nuclear Information System (INIS)

    Conrads, T.J.

    1998-01-01

    This document presents the natural phenomena hazard loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, and supports development of double-shell tank systems specifications at the Hanford Site in south-central Washington State. The natural phenomena covered are seismic, flood, wind, volcanic ash, lightning, snow, temperature, solar radiation, suspended sediment, and relative humidity

  16. Earthquake prediction with electromagnetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  17. Research in magnetospheric wave phenomena

    International Nuclear Information System (INIS)

    Barfield, J.N.

    1975-01-01

    During the last 4 years a number of developments have occurred which have led to an increased understanding of the role of wave phenomena in the physical processes of the magnetosphere. While the studies span the frequency regime from millihertz to the electron gyrofrequency, the developments to be discussed in this paper have in common that they have added substantially to the understanding of the controlling processes, regions, and boundaries in the magnetosphere. The topics discussed are the increased awareness and documentation of the role of the plasmapause in micropulsation generation and propagation; the establishment of the role of ion cyclotron waves in the wave-particle interactions at the plasmapause; the discovery of magnetospheric electrostatic waves with ω = (3/2)Ω/sub -/; the discovery and preliminary identification of the source of plasmaspheric hiss; and the analysis of storm time Pc 5 waves as observed on the satellites ATS 1 and Explorer 45. (auth)

  18. Emergent Phenomena at Oxide Interfaces

    International Nuclear Information System (INIS)

    Hwang, H.Y.

    2012-01-01

    Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r → -r. In the case of an insulator, breaking this symmetry can lead to spontaneous electric polarization, i.e. ferroelectricity, or pyroelectricity once the point group belongs to polar group symmetry. (ii) Time-reversal symmetry (T) defined as t → -t. In quantum mechanics, the time-evolution of the wave-function Ψ is given by the phase factor e -iEt/h b ar with E being the energy, and hence time-reversal basically corresponds to taking the complex conjugate of the wave-function. Also the spin, which is induced by the 'spinning' of the particle, is reversed by time-reversal. Broken T-symmetry is most naturally associated with magnetism, since the spin operator changes sign

  19. Transport phenomena in porous media

    CERN Document Server

    Ingham, Derek B

    1998-01-01

    Research into thermal convection in porous media has substantially increased during recent years due to its numerous practical applications. These problems have attracted the attention of industrialists, engineers and scientists from many very diversified disciplines, such as applied mathematics, chemical, civil, environmental, mechanical and nuclear engineering, geothermal physics and food science. Thus, there is a wealth of information now available on convective processes in porous media and it is therefore appropriate and timely to undertake a new critical evaluation of this contemporary information. Transport Phenomena in Porous Media contains 17 chapters and represents the collective work of 27 of the world's leading experts, from 12 countries, in heat transfer in porous media. The recent intensive research in this area has substantially raised the expectations for numerous new practical applications and this makes the book a most timely addition to the existing literature. It includes recent major deve...

  20. Electrostatic Phenomena on Planetary Surfaces

    Science.gov (United States)

    Calle, Carlos I.

    2017-02-01

    The diverse planetary environments in the solar system react in somewhat different ways to the encompassing influence of the Sun. These different interactions define the electrostatic phenomena that take place on and near planetary surfaces. The desire to understand the electrostatic environments of planetary surfaces goes beyond scientific inquiry. These environments have enormous implications for both human and robotic exploration of the solar system. This book describes in some detail what is known about the electrostatic environment of the solar system from early and current experiments on Earth as well as what is being learned from the instrumentation on the space exploration missions (NASA, European Space Agency, and the Japanese Space Agency) of the last few decades. It begins with a brief review of the basic principles of electrostatics.

  1. The quest for new phenomena

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1996-12-01

    The Standard Model of particle physics has been very successful in describing experimental data with great precision. With the exception of some neutrino anomalies, there is no data that is in disagreement with it. Nevertheless, the model is regarded as incomplete and unsatisfactory. There is no explanation of the pattern of quark and lepton masses and, possibly more important, no understanding of the scale of electroweak interactions. Electroweak symmetry breaking is implemented in the Standard Model from the presence of a scalar electroweak doublet, the Higgs field, that acquires a vacuum expectation value of order 250 GeV and leaves as a remnant one physical state, the electrically neutral Higgs boson whose mass is not predicted. In this talk, the author compares the techniques used at, and capabilities of, various facilities in searching for new phenomena. The author emphasizes the cases where information from more than one facility may be needed to fully explore the physics

  2. In-vessel phenomena -- CORA

    International Nuclear Information System (INIS)

    Ott, L.J.; Rij, W.I. van.

    1991-01-01

    Experiment-specific models have been employed since 1986 by Oak Ridge National Laboratory (ORNL) severe accident analysis programs for the purpose of boiling water reactor experimental planning and optimum interpretation of experimental results. The large integral tests performed to date, which start from an initial undamaged core state, have involved significantly different-from-prototypic boundary and experimental conditions because of either normal facility limitations or specific experimental constraints. These experiments (ACRR: DF-4, NRU: FLHT-6, and CORA) were designed to obtain specific phenomenological information such as the degradation and interaction of prototypic components and the effects on melt progression of control-blade materials and channel boxes. Applications of ORNL models specific to the KfK CORA-16 and CORA-17 experiments are discussed and significant findings from the experimental analyses such as the following are presented: applicability of available Zircaloy oxidation kinetics correlations; influence of cladding strain on Zircaloy oxidation; influence of spacer grids on the structural heatup; and the impact of treating the gaseous coolant as a gray interacting medium. The experiment-specific models supplement and support the systems-level accident analysis codes. They allow the analyst to accurately quantify the observed experimental phenomena and to compensate for the effect of known uncertainties. They provide a basis for the efficient development of new models for phenomena that are currently not modeled (such as material interactions). They can provide validated phenomenological models (from the results of the experiments) as candidates for incorporation in the systems-level ''whole-core'' codes

  3. Remote sensing of natural phenomena

    Directory of Open Access Journals (Sweden)

    Miodrag D. Regodić

    2014-06-01

    Full Text Available There has always been a need to directly perceive and study the events whose extent is beyond people's possibilities. In order to get new data and to make observations and studying much more objective in comparison with past syntheses - a new method of examination called remote sensing has been adopted. The paper deals with the principles and elements of remote sensing, as well as with the basic aspects of using remote research in examining meteorological (weather parameters and the conditions of the atmosphere. The usage of satellite images is possible in all phases of the global and systematic research of different natural phenomena when airplane and satellite images of different characteristics are used and their analysis and interpretation is carried out by viewing and computer added procedures. Introduction Remote sensing of the Earth enables observing and studying global and local events that occur on it. Satellite images are nowadays used in geology, agriculture, forestry, geodesy, meteorology, spatial and urbanism planning, designing of infrastructure and other objects, protection from natural and technological catastrophes, etc. It it possible to use satellite images in all phases of global and systematic research of different natural phenomena. Basics of remote sensing Remote sensing is a method of the acquisition and interpretation of information about remote objects without making a physical contact with them. The term Daljinska detekcija is a literal translation of the English term Remote Sensing. In French it isTeledetection, in German - Fernerkundung, in Russian - дистанционие иследования. We also use terms such as: remote survailance, remote research, teledetection, remote methods, and distance research. The basic elements included in Remote Sensing are: object, electromagnetic energy, sensor, platform, image, analysis, interpretation and the information (data, fact. Usage of satellite remote research in

  4. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...... to the recently derived plasma resonance phenomena for high T-c superconductors of the BSCCO type is discussed....

  5. Coherent amplification and pulsar phenomena

    International Nuclear Information System (INIS)

    Casperson, L.W.

    1977-01-01

    A modification of the rotating-star model has been developed to interpret the periodic energy bursts from pulsars. This new configuration involves theta-directed oscillation modes in the stellar atmosphere or magnetosphere, and most aspects of the typical pulse characteristics are well accounted for. Gain is provided by resonant interactions with particles trapped in the stellar magnetic field. The most significant feature is the fact that highly directional beaming of the output energy results as a natural consequence of coherence between the radiation fields emerging from various locations about the pulsar; and a localized radiation origin is not required. (Auth.)

  6. Advances in magnetic resonance 1

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 1, discusses developments in various areas of magnetic resonance. The subject matter ranges from original theoretical contributions through syntheses of points of view toward series of phenomena to critical and painstaking tabulations of experimental data. The book contains six chapters and begins with a discussion of the theory of relaxation processes. This is followed by separate chapters on the development of magnetic resonance techniques for studying rate processes in chemistry and the application of these techniques to various problems; the geometri

  7. EDITORIAL: Quantum phenomena in Nanotechnology Quantum phenomena in Nanotechnology

    Science.gov (United States)

    Loss, Daniel

    2009-10-01

    Twenty years ago the Institute of Physics launched the journal Nanotechnology from its publishing house based in the home town of Paul Dirac, a legendary figure in the development of quantum mechanics at the turn of the last century. At the beginning of the 20th century, the adoption of quantum mechanical descriptions of events transformed the existing deterministic world view. But in many ways it also revolutionised the progress of research itself. For the first time since the 17th century when Francis Bacon established inductive reasoning as the means of advancing science from fact to axiom to law, theory was progressing ahead of experiments instead of providing explanations for observations that had already been made. Dirac's postulation of antimatter through purely theoretical investigation before its observation is the archetypal example of theory leading the way for experiment. The progress of nanotechnology and the development of tools and techniques that enabled the investigation of systems at the nanoscale brought with them many fascinating observations of phenomena that could only be explained through quantum mechanics, first theoretically deduced decades previously. At the nanoscale, quantum confinement effects dominate the electrical and optical properties of systems. They also render new opportunities for manipulating the response of systems. For example, a better understanding of these systems has enabled the rapid development of quantum dots with precisely determined properties, which can be exploited in a range of applications from medical imaging and photovoltaic solar cells to quantum computation, a radically new information technology being currently developed in many labs worldwide. As the first ever academic journal in nanotechnology, {\\it Nanotechnology} has been the forum for papers detailing progress of the science through extremely exciting times. In the early years of the journal, the investigation of electron spin led to the formulation

  8. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  9. Poorly studied phenomena in geoelectrics

    Directory of Open Access Journals (Sweden)

    В. С. Могилатов

    2016-12-01

    Full Text Available Undoubtedly, modern geoelectric technologies emerge in the result of the development of traditional approaches and techniques. However of more interest is the appearance of completely new technologies based on new effects and new models of interaction of geological medium and electromagnetic field. The author does not commit to indicate principally new directions, but only wants to discuss some poorly known facts from the theory and practice of geoelectrics. The outcome of this study could be considered attracting the attention of experts to non-traditional signals in geoelectrics. The reviewed phenomena of interest, not fully implemented in practice in the author’s opinion, are field split into two polarizations: transverse electric (the ТЕ-field and transverse magnetic (the ТМ-field, then some poorly known properties of ТМ-field, the role of bias currents, the anisotropy of horizontal resistances, the role of geomagnetic field in geoelectric sounding, the unique resolution of CSEM (Controlled Source Electro-Magnetic techniques at sea.

  10. Transient phenomena in multiphase flow

    International Nuclear Information System (INIS)

    Afgan, N.H.

    1988-01-01

    This book is devoted to formulation of the two-phase system. Emphasis is given to classical instantaneous equations of mass momentum and energy for local conditions and respective averaging procedures and their relevance to the structure of transfer laws. In formulating an equation for a two-velocity continuum, two-phase dispersed flow, two-velocity and local inertial effects associated with contraction and expansion of the mixture have been considered. Particular attention is paid to the effects of interface topology and area concentration as well as the latter's dependence on interfacial transfer laws. Also covered are low bubble concentrations in basic nonuniform unsteady flow where interactions between bubbles are negligible but where the effects of bubbles must still be considered. Special emphasis has been given to the pairwise interaction of the bubble and respective hydrodynamic equations describing the motion of a pair of spherical bubbles through a liquid This book introduces turbulence phenomena in two-phase flow and related problems of phase distribution in two-phase flow. This includes an extensive survey of turbulence and phase distribution models in transient two-phase flow. It is shown that if the turbulent structure of the continuous phase of bubbly two-phase is either measured or can be predicted, then the observed lateral phase distribution can be determined by using an multidimensional two-fluid model in which all lateral forces are properly modeled

  11. Electrostatic phenomena in volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Lane, S J; James, M R; Gilbert, J S, E-mail: s.lane@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2011-06-23

    Electrostatic phenomena have long been associated with the explosive eruption of volcanoes. Lightning generated in volcanic plumes is a spectacular atmospheric electrical event that requires development of large potential gradients over distances of up to kilometres. This process begins as hydrated liquid rock (magma) ascends towards Earth's surface. Pressure reduction causes water supersaturation in the magma and the development of bubbles of supercritical water, where deeper than c. 1000 m, and water vapour at shallower depths that drives flow expansion. The generation of high strain rates in the expanding bubbly magma can cause it to fracture in a brittle manner, as deformation relaxation timescales are exceeded. The brittle fracture provides the initial charge separation mechanism, known as fractoemission. The resulting mixture of charged silicate particles and ions evolves over time, generating macro-scale potential gradients in the atmosphere and driving processes such as particle aggregation. For the silicate particles, aggregation driven by electrostatic effects is most significant for particles smaller than c. 100 {mu}m. Aggregation acts to change the effective aerodynamic behaviour of silicate particles, thus altering the sedimentation rates of particles from volcanic plumes from the atmosphere. The presence of liquid phases also promotes aggregation processes and lightning.

  12. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos

    2017-07-06

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration, and surfactant concentration; on the other hand, the contact angle responds to interfacial tensions, surface topography, invasion velocity, and chemical interactions. Interfaces are not isolated but interact through the fluid pressure and respond to external fields. Jumps, snap-offs and percolating wetting liquids along edges and crevices are ubiquitous in real, non-cylindrical porous networks. Pore- and macroscale instabilities together with pore structure variability-and-correlation favor fluid trapping and hinder recovery efficiency. The saturation-pressure characteristic curve is affected by the saturation-history, flow-rate, the mechanical response of the porous medium, and time-dependent reactive and diffusive processes; in addition, there are salient differences between unsaturation by internal gas nucleation and gas invasion. Capillary forces add to other skeletal forces in the porous medium and can generate open-mode discontinuities when the capillary entry pressure is high relative to the effective stress. Time emerges as an important variable in mixed-fluid conditions and common quasi-static analyses may fail to capture the system response.

  13. The effect of asymmetry on resonant tunneling

    International Nuclear Information System (INIS)

    Garcia-Calderon, G.

    1986-07-01

    Resonant tunneling experiments on multibarrier coupled heterostructures probe the quasistationary nature of the states of the corresponding one dimensional potential. This work considers the effect of asymmetric one dimensional multibarrier potentials on resonant tunneling. It is shown, by using the properties of the propagator of the system, that this effect may lead to novel resonance phenomena and affects the lifetime of the quasistationary states of the system. The above considerations are illustrated by a simple analytical solvable model. (author)

  14. Observation of Celestial Phenomena in Ancient China

    Science.gov (United States)

    Sun, Xiaochun

    Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

  15. Searches for new phenomena in leptonic final states using the ATLAS detector

    CERN Document Server

    Mankinen, Katja Hannele; The ATLAS collaboration

    2018-01-01

    Many theories beyond the Standard Model predict new phenomena which decay to well isolated, high-pt leptons. Searches for such new physics models are performed using the ATLAS experiment at the LHC, by looking for resonances in the dilepton mass spectrum or excesses in the tail of the transverse mass distribution for various lepton flavours. Selected recent results will be discussed.

  16. Phase-locking phenomena and excitation of damped and driven nonlinear oscillators

    DEFF Research Database (Denmark)

    Shagalov, A.G.; Juul Rasmussen, Jens; Naulin, Volker

    2009-01-01

    Resonant phase-locking phenomena ('autoresonance') in the van der Pol Duffing oscillator forced by a small amplitude periodic driving with slowly varying frequency have been studied. We show that autoresonance occurs for oscillators with sufficiently small damping, when the system may have bi-stable...

  17. Nonlinear dynamical phenomena in liquid crystals

    International Nuclear Information System (INIS)

    Wang, X.Y.; Sun, Z.M.

    1988-09-01

    Because of the existence of the orientational order and anisotropy in liquid crystals, strong nonlinear phenomena and singular behaviors, such as solitary wave, transient periodic structure, chaos, fractal and viscous fingering, can be excited by a very small disturbance. These phenomena and behaviors are in connection with physics, biology and mathematics. 12 refs, 6 figs

  18. Polarization phenomena in heavy-ion reactions

    International Nuclear Information System (INIS)

    Sugimoto, K.; Ishihara, M.; Takahashi, N.

    1984-01-01

    This chapter presents a few key experiments which provide direct evidence of the polarization phenomena in heavy-ion reactions. The theory of polarization observables and measurements is given with the necessary formulae. The polarization phenomena is described and studies of product nuclear polarization in heavy-ion reactions are discussed. Studies of heavy-ion reactions induced by polarized beams are examined

  19. A Connection between Transport Phenomena and Thermodynamics

    Science.gov (United States)

    Swaney, Ross; Bird, R. Byron

    2017-01-01

    Although students take courses in transport phenomena and thermodynamics, they probably do not ask whether these two subjects are related. Here we give an answer to that question. Specifically we give relationships between the equations of change for total energy, internal energy, and entropy of transport phenomena and key equations of equilibrium…

  20. Nonlinear dynamics of drops and bubbles and chaotic phenomena

    Science.gov (United States)

    Trinh, Eugene H.; Leal, L. G.; Feng, Z. C.; Holt, R. G.

    1994-01-01

    Nonlinear phenomena associated with the dynamics of free drops and bubbles are investigated analytically, numerically and experimentally. Although newly developed levitation and measurement techniques have been implemented, the full experimental validation of theoretical predictions has been hindered by interfering artifacts associated with levitation in the Earth gravitational field. The low gravity environment of orbital space flight has been shown to provide a more quiescent environment which can be utilized to better match the idealized theoretical conditions. The research effort described in this paper is a closely coupled collaboration between predictive and guiding theoretical activities and a unique experimental program involving the ultrasonic and electrostatic levitation of single droplets and bubbles. The goal is to develop and to validate methods based on nonlinear dynamics for the understanding of the large amplitude oscillatory response of single drops and bubbles to both isotropic and asymmetric pressure stimuli. The first specific area on interest has been the resonant coupling between volume and shape oscillatory modes isolated gas or vapor bubbles in a liquid host. The result of multiple time-scale asymptotic treatment, combined with domain perturbation and bifurcation methods, has been the prediction of resonant and near-resonant coupling between volume and shape modes leading to stable as well as chaotic oscillations. Experimental investigations of the large amplitude shape oscillation modes of centimeter-size single bubbles trapped in water at 1 G and under reduced hydrostatic pressure, have suggested the possibility of a low gravity experiment to study the direct coupling between these low frequency shape modes and the volume pulsation, sound-radiating mode. The second subject of interest has involved numerical modeling, using the boundary integral method, of the large amplitude shape oscillations of charged and uncharged drops in the presence

  1. Fourier transform nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Geick, R.

    1981-01-01

    This review starts with the basic principles of resonance phenomena in physical systems. Especially, the connection is shown between the properties of these systems and Fourier transforms. Next, we discuss the principles of nuclear magnetic resonance. Starting from the general properties of physical systems showing resonance phenomena and from the special properties of nuclear spin systems, the main part of this paper reviews pulse and Fourier methods in nuclear magnetic resonance. Among pulse methods, an introduction will be given to spin echoes, and, apart from the principle of Fourier transform nuclear magnetic resonance, an introduction to the technical problems of this method, e.g. resolution in the frequency domain, aliasing, phase and intensity errors, stationary state of the spin systems for repetitive measurements, proton decoupling, and application of Fourier methods to systems in a nonequilibrium state. The last section is devoted to special applications of Fourier methods and recent developments, e.g. measurement of relaxation times, solvent peak suppression, 'rapid scan'-method, methods for suppressing the effects of dipolar coupling in solids, two-dimensional Fourier transform nuclear magnetic resonance, and spin mapping or zeugmatography. (author)

  2. Precedent Phenomena in Quebecois Linguistic World View

    Directory of Open Access Journals (Sweden)

    Ксения Эдуардовна Болотина

    2016-12-01

    Full Text Available This article is devoted to the linguocultural analysis of precedent phenomena as parts of Quebecois’ cognitive base. Precedent phenomena being cultural facts are one of the key issues in modern linguistic and cognitive studies. By precedent phenomena we mean, according to Y.E. Prohorov, such entities when verbalized in discourse that refer to a certain cultural fact behind them. In the article the precedent phenomena such as precedent text, precedent situation, precedent utterance, and precedent name are analyzed. The main theses of the precedence theory given in the article (Y.N. Karaulov, Y.E. Prohorov, V.V. Krasnyh, D.B. Gudkov are at the heart of precedence studies on the basis of different languages. However, a complex analysis of precedent phenomena in the Quebec national variant of French is new to Russian linguistics. The study of precedent phenomena enables us to elicit features of their functioning in ethnospecific discourse and determine cultural dominants existing in Quebecois’ linguistic world view. Given the fact that the size of the article is limited, we undertooke the analysis of eight phenomena precedent of the bearers of Quebec linguoculture. The choice of phenomena is determined by the frequency of their use in discourse. The facts analyzed are of national character, i.e. known to all members of the linguocultural community. A certain cultural fact is at the very core of each precedent phenomenon given in the article. To get the whole picture we analysed historic, political, and cultural context connected to the precedent phenomena in question. The study enables us to elicit distinctive features that are at the core of each phenomenon. The results are backed with the supportive material drawn from analysis of different types of discourse. The analysis of precedent phenomena undertaken in this article allows us to reconstruct, to a certain extent, Quebec cultural space and is a stepping stone to the reconstruction of the

  3. Multiphoton resonances

    International Nuclear Information System (INIS)

    Shore, B.W.

    1977-01-01

    The long-time average of level populations in a coherently-excited anharmonic sequence of energy levels (e.g., an anharmonic oscillator) exhibits sharp resonances as a function of laser frequency. For simple linearly-increasing anharmonicity, each resonance is a superposition of various multiphoton resonances (e.g., a superposition of 3, 5, 7, . . . photon resonances), each having its own characteristic width predictable from perturbation theory

  4. Interfacial polarization phenomena in organic molecular films

    International Nuclear Information System (INIS)

    Iwamoto, Mitsumasa; Manaka, Takaaki

    2006-01-01

    Electrostatic phenomena occurring at the interface between metal/organic and organic/organic materials are discussed from the viewpoint of dielectrics physics. Focusing on two important origins of surface polarization phenomena, orientational ordering of polar molecules and displacement of excess charges at the interface, surface polarization phenomena of organic thin films are discussed. To define the orientational order of polar molecules, orientational order parameters are introduced, and surface polarization due to the alignment of dipoles is expressed. The generation of Maxwell displacement current (MDC) and optical second harmonic generation (SHG) that are specific for surface organic monomolecular films are discussed, and some experimental evidence are shown. As an extension of the concept of surface Fermi level introduced to discuss the electrostatic phenomena due to electron transfer at the interface between metal-organic insulators, the surface Fermi level is extended to the discussion on the electrostatic phenomena of organic semiconductor materials on metals. In this paper, some experimental evidence of surface polarization originating from polar molecules and displacement of excess charges are shown. After that, with consideration of these surface phenomena, single electron tunneling of organic films are briefly discussed in association with surface polarization phenomena

  5. A statistical approach to strange diffusion phenomena

    International Nuclear Information System (INIS)

    Milligen, B.Ph. van; Carreras, B.A.; Sanchez, R.

    2005-01-01

    The study of particle (and heat) transport in fusion plasmas has revealed the existence of what might be called 'unusual' transport phenomena. Such phenomena are: unexpected scaling of the confinement time with system size, power degradation (i.e. sub-linear scaling of energy content with power input), profile stiffness (also known as profile consistency), rapid transient transport phenomena such as cold and heat pulses (travelling much faster than the diffusive timescale would allow), non-local behaviour and central profile peaking during off-axis heating, associated with unexplained inward pinches. The standard modelling framework, essentially equal to Fick's Law plus extensions, has great difficulty in providing an all-encompassing and satisfactory explanation of all these phenomena. This difficulty has motivated us to reconsider the basics of the modelling of diffusive phenomena. Diffusion is based on the well-known random walk. The random walk is captured in all its generality in the Continuous Time Random Walk (CTRW) formalism. The CTRW formalism is directly related to the well-known Generalized Master Equation, which describes the behaviour of tracer particle diffusion on a very fundamental level, and from which the phenomenological Fick's Law can be derived under some specific assumptions. We show that these assumptions are not necessarily satisfied under fusion plasma conditions, in which case other equations (such as the Fokker-Planck diffusion law or the Master Equation itself) provide a better description of the phenomena. This fact may explain part of the observed 'strange' phenomena (namely, the inward pinch). To show how the remaining phenomena mentioned above may perhaps find an explanation in the proposed alternative modelling framework, we have designed a toy model that incorporates a critical gradient mechanism, switching between rapid (super-diffusive) and normal diffusive transport as a function of the local gradient. It is then demonstrated

  6. Fourteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Kobayashi, Takayoshi; Kobayashi, Tetsuro; Nelson, Keith A; Silvestri, Sandro; Ultrafast Phenomena XIV

    2005-01-01

    Ultrafast Phenomena XIV presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico-, femto-, and atosecond processes relevant in physics, chemistry, biology and engineering are presented. Ultrafast technology is now having a profound impact within a wide range of applications, among them imaging, material diagnostics, and transformation and high-speed optoelectronics. This book summarizes results presented at the 14th Ultrafast Phenomena Conference and reviews the state of the art in this important and rapidly advancing field.

  7. Transient phenomena in electrical power systems

    CERN Document Server

    Venikov, V A; Higinbotham, W

    1964-01-01

    Electronics and Instrumentation, Volume 24: Transient Phenomena in Electrical Power Systems presents the methods for calculating the stability and the transient behavior of systems with forced excitation control. This book provides information pertinent to the analysis of transient phenomena in electro-mechanical systems.Organized into five chapters, this volume begins with an overview of the principal requirements in an excitation system. This text then explains the electromagnetic and electro-mechanical phenomena, taking into account the mutual action between the components of the system. Ot

  8. Computational transport phenomena for engineering analyses

    CERN Document Server

    Farmer, Richard C; Cheng, Gary C; Chen, Yen-Sen

    2009-01-01

    Computational Transport PhenomenaOverviewTransport PhenomenaAnalyzing Transport PhenomenaA Computational Tool: The CTP CodeVerification, Validation, and GeneralizationSummaryNomenclatureReferencesThe Equations of ChangeIntroductionDerivation of The Continuity EquationDerivation of The Species Continuity EquationDerivation of The Equation Of MotionDerivation of The General Energy EquationNon-Newtonian FluidsGeneral Property BalanceAnalytical and Approximate Solutions for the Equations of ChangeSummaryNomenclatureReferencesPhysical PropertiesOverviewReal-Fluid ThermodynamicsChemical Equilibrium

  9. Nonlinear Photonics and Novel Optical Phenomena

    CERN Document Server

    Morandotti, Roberto

    2012-01-01

    Nonlinear Photonics and Novel Optical Phenomena contains contributed chapters from leading experts in nonlinear optics and photonics, and provides a comprehensive survey of fundamental concepts as well as hot topics in current research on nonlinear optical waves and related novel phenomena. The book covers self-accelerating airy beams, integrated photonics based on high index doped-silica glass, linear and nonlinear spatial beam dynamics in photonic lattices and waveguide arrays, polariton solitons and localized structures in semiconductor microcavities, terahertz waves, and other novel phenomena in different nanophotonic and optical systems.

  10. Sixteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Corkum, Paul; Nelson, Keith A; Riedle, Eberhard; Schoenlein, Robert W; Ultrafast Phenomena XVI

    2009-01-01

    Ultrafast Phenomena XVI presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh speed communications. This book summarizes the results presented at the 16th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.

  11. Heat transfer phenomena revelant to severe accidents

    International Nuclear Information System (INIS)

    Dallman, R.J.; Duffey, R.B.

    1990-01-01

    A number of aspects of severe accidents have been reviewed, particularly in relation to the heat transfer characteristics and the important phenomena. It is shown that natural circulation, forced convection, and entrainment phenomena are important for both the reactor system and ex-vessel events. It is also shown that the phenomena related to two component enhanced heat transfer is important in the pool of molten core debris, in relation to the potential for attack of the liner structure and the concrete. These mechanisms are discussed within the general context of severe accident progression

  12. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

    2003-01-01

    A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  13. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  14. Heat transfer phenomena relevant to severe accidents

    International Nuclear Information System (INIS)

    Dallman, R.J.; Duffey, R.B.

    1990-01-01

    A number of aspects of severe accidents have been reviewed, particularly in relation to the heat transfer characteristics and the important phenomena. It is shown that natural circulation, forced convection, and entrainment phenomena are important for both the reactor system and ex-vessel events. It is also shown that the phenomena related to two component enhanced heat transfer is important in the pool of molten core debris, in relation to the potential for attack of the liner structure and the concrete. These mechanisms are discussed within the general context of severe accident progression. 26 refs

  15. Classifying prion and prion-like phenomena.

    Science.gov (United States)

    Harbi, Djamel; Harrison, Paul M

    2014-01-01

    The universe of prion and prion-like phenomena has expanded significantly in the past several years. Here, we overview the challenges in classifying this data informatically, given that terms such as "prion-like", "prion-related" or "prion-forming" do not have a stable meaning in the scientific literature. We examine the spectrum of proteins that have been described in the literature as forming prions, and discuss how "prion" can have a range of meaning, with a strict definition being for demonstration of infection with in vitro-derived recombinant prions. We suggest that although prion/prion-like phenomena can largely be apportioned into a small number of broad groups dependent on the type of transmissibility evidence for them, as new phenomena are discovered in the coming years, a detailed ontological approach might be necessary that allows for subtle definition of different "flavors" of prion / prion-like phenomena.

  16. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  17. Canister storage building natural phenomena design loads

    International Nuclear Information System (INIS)

    Tallman, A.M.

    1996-02-01

    This document presents natural phenomena hazard (NPH) loads for use in the design and construction of the Canister Storage Building (CSB), which will be located in the 200 East Area of the Hanford Site

  18. Didactic demonstrations of superfluidity and superconductivity phenomena

    International Nuclear Information System (INIS)

    Aniola-Jedrzejak, L.; Lewicki, A.; Pilipowicz, A.; Tarnawski, Z.; Bialek, H.

    1980-01-01

    In order to demonstrate to students phenomena of superfluidity and superconductivity a special helium cryostat has been constructed. The demonstrated effects, construction of the cryostat and the method of demonstration are described. (author)

  19. High Temperature Phenomena in Shock Waves

    CERN Document Server

    2012-01-01

    The high temperatures generated in gases by shock waves give rise to physical and chemical phenomena such as molecular vibrational excitation, dissociation, ionization, chemical reactions and inherently related radiation. In continuum regime, these processes start from the wave front, so that generally the gaseous media behind shock waves may be in a thermodynamic and chemical non-equilibrium state. This book presents the state of knowledge of these phenomena. Thus, the thermodynamic properties of high temperature gases, including the plasma state are described, as well as the kinetics of the various chemical phenomena cited above. Numerous results of measurement and computation of vibrational relaxation times, dissociation and reaction rate constants are given, and various ionization and radiative mechanisms and processes are presented. The coupling between these different phenomena is taken into account as well as their interaction with the flow-field. Particular points such as the case of rarefied flows an...

  20. Transport phenomena an introduction to advanced topics

    CERN Document Server

    Glasgow, Larry A

    2010-01-01

    Enables readers to apply transport phenomena principles to solve advanced problems in all areas of engineering and science This book helps readers elevate their understanding of, and their ability to apply, transport phenomena by introducing a broad range of advanced topics as well as analytical and numerical solution techniques. Readers gain the ability to solve complex problems generally not addressed in undergraduate-level courses, including nonlinear, multidimensional transport, and transient molecular and convective transport scenarios. Avoiding rote memorization, the author em

  1. Evidence on Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Malene Rode; Sommersel, Hanna Bjørnøy; Larsen, Michael Søgaard

    This publication is an excerpt from the full technical report ‘Dropout Phenomena at Universities: What is Dropout? Why does Dropout Occur? What Can be Done by the Universities to Prevent or Reduce it? A systematic review’, which was completed in April 2013. The purpose of this excerpt is to present...... the knowledge we have on dropout phenomena at European universities in a short, precise and comprehensible form to allow readers to orient themselves on the subject in a more readable manner....

  2. Polarization phenomena in two body systems

    International Nuclear Information System (INIS)

    Thomas, G.H.

    1978-01-01

    A review is given of strong interactions at very low, low, intermediate, and high energies over the range 6.14 MeV to 150 GeV/c with regard to polarization phenomena in two-body systems. From the one-pion-exchange model to the theory that can possibly relate to all the phenomena, namely, quantum electrodynamics the review pointed to a unified explanation for the interactions under study. 46 references

  3. Giant resonances: reaction theory approach

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de; Foglia, G.A.

    1989-09-01

    The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

  4. Second DOE natural phenomena hazards mitigation conference

    International Nuclear Information System (INIS)

    1989-01-01

    This conference has been organized into ten presentation sessions which include an overview of the DOE Natural Phenomena Guidelines, Seismic Analysis, Seismic Design, Modifying Existing Facilities, DOE Orders, Codes, and Standards (2 sessions), Seismic Hazard (2 sessions), and Probabilistic Risk Assessment (2 sessions). Two poster sessions were also included in the program to provide a different forum for communication of ideas. Over the past fourteen years, Lawrence Livermore National Laboratory, Nuclear Systems Safety Program, has been working with the US Department of Energy, Office of Safety Appraisals and their predecessors in the area of natural phenomena hazards. During this time we have developed seismic, extreme wind/tornado, and flood hazard models for DOE sites in the United States. Guidelines for designing and evaluating DOE facilities for natural phenomena have been developed and are in interim use throughout the DOE community. A series of state-of-the practice manuals have also been developed to aid the designers. All of this material is listed in the Natural Phenomena Hazards Bibliography included in these proceedings. This conference provides a mechanism to disseminate current information on natural phenomena hazards and their mitigation. It provides an opportunity to bring together members of the DOE community to discuss current projects, to share information, and to hear practicing members of the structural engineering community discuss their experiences from past natural phenomena, future trends, and any changes to building codes. Each paper or poster presented is included in these proceedings. We have also included material related to the luncheon and dinner talks

  5. Study of interfacial phenomena for bio/chemical sensing applications

    Science.gov (United States)

    Min, Hwall

    This work presents the fundamental study of biological and chemical interfacial phenomena and (bio)chemical sensing applications using high frequency resonator arrays. To realize a versatile (bio)chemical sensing system for the fundamental study as well as their practical applications, the following three distinct components were studied and developed: i) detection platforms with high sensitivity, ii) novel innovative sensing materials with high selectivity, iii) analytical model for data interpretation. 8-pixel micromachined quartz crystal resonator (muQCR) arrays with a fundamental resonance frequency of 60 ¡V 90 MHz have been used to provide a reliable detection platform with high sensitivity. Room temperature ionic liquid (RTIL) has been explored and integrated into the sensing system as a smart chemical sensing material. The use of nanoporous gold (np-Au) enables the combination of the resonator and surface-enhanced Raman spectroscopy for both quantitative and qualitative measurement. A statistical model for the characterization of resonator behavior to study the protein adsorption kinetics is developed by random sequential adsorption (RSA) approach with the integration of an effective surface depletion theory. The investigation of the adsorption kinetics of blood proteins is reported as the fundamental study of biological phenomena using the proposed sensing system. The aim of this work is to study different aspects of protein adsorption and kinetics of adsorption process with blood proteins on different surfaces. We specifically focus on surface depletion effect in conjunction with the RSA model to explain the observed adsorption isotherm characteristics. A number of case studies on protein adsorption conducted using the proposed sensing system has been discussed. Effort is specifically made to understand adsorption kinetics, and the effect of surface on the adsorption process as well as the properties of the adsorbed protein layer. The second half of the

  6. Magnetic resonance and its applications

    CERN Document Server

    Chizhik, Vladimir I; Donets, Alexey V; Frolov, Vyacheslav V; Komolkin, Andrei V; Shelyapina, Marina G

    2014-01-01

    The book provides a basic understanding of the underlying theory, fundamentals and applications of magnetic resonance The book implies a few levels of the consideration (from simple to complex) of phenomena, that can be useful for different groups of readers The introductory chapter provides the necessary underpinning knowledge for newcomers to the methods The exposition of theoretical materials goes from initial to final formulas through detailed intermediate expressions.

  7. Separation phenomena in Liquids and Gases

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P; Soubbaramayer, [CEA Saclay, Dept. des Lasers et de la Physico-Chimie, DESICP/DLPC/SPP, 91 - Gif-sur-Yvette (France); Noe, P

    1989-07-01

    technology was up to the task but the programme was shelved mainly because of lack of demand. Finally, seven papers deal with laser processes. Two of them review the AVLIS program in the UK and one paper gives the status of the MLIS project in West Germany. One communication from China and three papers by French authors deal with specific problems currently met in AVLIS studies, on the vapour beam and the ion extraction. A number of phenomena observed in AVLIS needs satisfactory explanations: the high value of the vapour velocity, the low value of metastables in the vapour beam, the extraction of ions at high density, etc. Session 1: plasma separation (review of isotopic plasma separation processes; production of depleted zirconium using a plasma centrifuge; measurements of isotope separation in a vacuum arc centrifuge). Session 2: plasma separation and centrifugation (recent developments in stable isotope separation by ionic cyclotron resonance; some aspects of the separation of multi-isotope mixtures with gas centrifuges; review paper on centrifuge technology and status of the URENCO centrifuge project; solution of the two-fluid equations for flow in a centrifuge; influence of stationary poles in the central region of gas centrifuges; extension of the analytic sixth order theory; applications of different analytic solutions for the centrifuge flow). Sessions 4 and 5: rotating flows (convection flows driven by centrifugal buoyancy in rapidly rotating systems; experimental investigation of the flow in a rotating pie-shaped cylinder; temperature distribution on rotating spherical shells; centrifugal separation of a suspension in a rotating vessel; spin-up from rest of a suspension - preliminary insight). Session 6: particle fluid mixture (modelling, simulation and comprehension of the flow field of a particles-fluid mixture; the effect of shear and lift on particle-gas separation; on the hydrodynamics of electrolytic refining of metals). Session 7 (calculation of condensation

  8. Separation phenomena in Liquids and Gases

    International Nuclear Information System (INIS)

    Louvet, P.; Dr Soubbaramayer; Noe, P.

    1989-01-01

    technology was up to the task but the programme was shelved mainly because of lack of demand. Finally, seven papers deal with laser processes. Two of them review the AVLIS program in the UK and one paper gives the status of the MLIS project in West Germany. One communication from China and three papers by French authors deal with specific problems currently met in AVLIS studies, on the vapour beam and the ion extraction. A number of phenomena observed in AVLIS needs satisfactory explanations: the high value of the vapour velocity, the low value of metastables in the vapour beam, the extraction of ions at high density, etc. Session 1: plasma separation (review of isotopic plasma separation processes; production of depleted zirconium using a plasma centrifuge; measurements of isotope separation in a vacuum arc centrifuge). Session 2: plasma separation and centrifugation (recent developments in stable isotope separation by ionic cyclotron resonance; some aspects of the separation of multi-isotope mixtures with gas centrifuges; review paper on centrifuge technology and status of the URENCO centrifuge project; solution of the two-fluid equations for flow in a centrifuge; influence of stationary poles in the central region of gas centrifuges; extension of the analytic sixth order theory; applications of different analytic solutions for the centrifuge flow). Sessions 4 and 5: rotating flows (convection flows driven by centrifugal buoyancy in rapidly rotating systems; experimental investigation of the flow in a rotating pie-shaped cylinder; temperature distribution on rotating spherical shells; centrifugal separation of a suspension in a rotating vessel; spin-up from rest of a suspension - preliminary insight). Session 6: particle fluid mixture (modelling, simulation and comprehension of the flow field of a particles-fluid mixture; the effect of shear and lift on particle-gas separation; on the hydrodynamics of electrolytic refining of metals). Session 7 (calculation of condensation

  9. Coherent Nonlinear Longitudinal Phenomena in Unbunched Synchrotron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Spentzouris, Linda Klamp [Northwestern U.

    1996-12-01

    Coherent nonlinear longitudinal phenomena are studied in proton and antiproton synchrotron beams. Theoretical development done in the eld of plasma physics for resonant wave-wave coupling is applied to the case of a particle beam. Results are given from experiments done to investigate the nature of the weakly nonlinear three-wave coupling processes known as parametric coupling and echoes. Storage ring impedances are shown to amplify the parametric coupling process, underlining the possibility that machine impedances might be extracted from coupling events instigated by external excitation. Echo amplitudes are demonstrated to be sensitive to diusion processes, such as intrabeam scattering, which degrade a beam. The result of a fast diusion rate measurement using echo amplitudes is presented. In addition to the wave-wave interactions, observations of moderately nonlinear waveparticle interactions are also included. The manifestations of these interactions that are documented include nonlinear Landau damping, higher harmonic generation, and signs of the possible formation of solitons.

  10. Kinetic Modifications to MHD Phenomena in Toroidal Plasmas

    International Nuclear Information System (INIS)

    Cheng, C.Z.; Gorelenkov, N.N.; Kramer, G.J.; Fredrickson, E.

    2004-01-01

    Particle kinetic effects involving small spatial and fast temporal scales can strongly affect MHD phenomena and the long time behavior of plasmas. In particular, kinetic effects such as finite ion gyroradii, trapped particle dynamics, and wave-particle resonances have been shown to greatly modify the stability of MHD modes. Here, the kinetic effects of trapped electron dynamics and finite ion gyroradii are shown to have a large stabilizing effect on kinetic ballooning modes in low aspect ratio toroidal plasmas such as NSTX [National Spherical Torus Experiment]. We also present the analysis of Toroidicity-induced Alfven Eigenmodes (TAEs) destabilized by fast neutral-beam injected ions in NSTX experiments and TAE stability in ITER due to alpha-particles and MeV negatively charged neutral beam injected ions

  11. Experimental study on dynamic buckling phenomena for supercavitating underwater vehicle

    Directory of Open Access Journals (Sweden)

    Minho Chung

    2012-09-01

    Full Text Available Dynamic buckling, also known as parametric resonance, is one of the dynamic instability phenomena which may lead to catastrophic failure of structures. It occurs when compressive dynamic loading is applied to the structures. Therefore it is essential to establish a reliable procedure to test and evaluate the dynamic buckling behaviors of structures, especially when the structure is designed to be utilized in compressive dynamic loading environment, such as supercavitating underwater vehicle. In the line of thought, a dynamic buckling test system is designed in this work. Using the test system, dynamic buckling tests including beam, plate, and stiffened plate are carried out, and the dynamic buckling characteristics of considered structures are investigated experimentally as well as theoretically and numerically.

  12. Geochemical modelling: what phenomena are missing

    International Nuclear Information System (INIS)

    Jacquier, P.

    1989-12-01

    In the framework of safety assessment of radioactive waste disposal, retention phenomena are usually taken into account by the Kd concept. It is well recognized that this concept is not enough for safety assessment models, because of the several and strong assumptions which are involved in this kind of representation. One way to have a better representation of the retention phenomena, is to substitute for this Kd concept an explicit description of geochemical phenomena and then couple transport codes with geochemical codes in a fully or a two-step procedure. We use currently such codes, but the scope of this paper is to display the limits today of the geochemical modelling in connection with sites analysis for deep disposal. In this paper, we intend to give an overview of phenomena which are missing in the geochemical models, or which are not completely introduced in the models. We can distinguish, on one hand phenomena for which modelling concepts exist such as adsorption/desorption and, on the other hand, phenomena for which modelling concepts do not exist for the moment such as colloids, and complexation by polyelectrolyte solutions (organics). Moreover we have to take care of very low concentrations of radionuclides, which can be expected from the leaching processes in the repository. Under those conditions, some reactions may not occur. After a critical review of the involved phenomena, we intend to stress the main directions of the wishful evolution of the geochemical modelling. This evolution should improve substantially the quality of the above-mentioned site assessments

  13. Synchrobetatron resonances

    International Nuclear Information System (INIS)

    1977-03-01

    At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. While the existence of sideband resonances of the main betatron oscillation frequencies has been previously observed and analyzed, the resonances observed in SPEAR do not appear to be of the same variety. Experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented

  14. Snake resonances

    International Nuclear Information System (INIS)

    Tepikian, S.

    1988-01-01

    Siberian Snakes provide a practical means of obtaining polarized proton beams in large accelerators. The effect of snakes can be understood by studying the dynamics of spin precession in an accelerator with snakes and a single spin resonance. This leads to a new class of energy independent spin depolarizing resonances, called snake resonances. In designing a large accelerator with snakes to preserve the spin polarization, there is an added constraint on the choice of the vertical betatron tune due to the snake resonances. 11 refs., 4 figs

  15. [Spiritual phenomena occurring in everybody and health].

    Science.gov (United States)

    Krsiak, M

    2008-01-01

    The past several years have seen an explosion of research in the area of spirituality and health. However, confusion and incomprehension of the conception of spirituality (e.g. confounding spirituality with various conventional views on religiousness) hampers better understanding in this area. The present paper proposes definition of spiritual phenomena in man based on natural epistemological and instrumental criteria (whether a certain phenomenon can be objectively known and evoked): spiritual phenomena in man are those, which cannot be objectively known nor evoked, but which act (e.g., love, idea). Spiritual phenomena can be really known only in the self ("in spirit"). Objectively known can be only manifestations of spiritual phenomena. Some attributes of love (e.g. its personal uniqueness) or ideas (e.g., sense of own life) whose satisfaction appears to be important for health are briefly outlined. A review of some frequently cited recent papers investigating the role of spirituality in health and discussion of frequent pitfalls in this area is given. Spirituality is a universal human phenomenon. All human beings, secular or religious, encounter with spiritual phenomena. Although the present conception of spirituality distances from some conventional views on religiousness, it is not atheistic. On the contrary, it accommodates the basic religious concept "God is love". Conceptual clarification is essential for further progress in the study of impact of spirituality on health.

  16. The making of extraordinary psychological phenomena.

    Science.gov (United States)

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. © 2012 Wiley Periodicals, Inc.

  17. Resonance probe; La sonde a resonance

    Energy Technology Data Exchange (ETDEWEB)

    Lepechinsky, D; Messiaen, A; Rolland, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    After a brief review of papers recently published on the resonance probe as a tool for plasma diagnostics, the main features of the theory proposed by one of us are recalled. In this theory the geometry of the resonator formed by the probe, the ion sheath and the plasma is explicitly taken into account with the quasi-static and cold plasma approximations. Some new results emerging from this theory are indicated and a comparison with experimental data obtained with a spherical probe placed in a quiescent mercury-vapour plasma is made. A good quantitative agreement has been observed, indicating that the theory is satisfactory and justifying the assumptions involved. Nevertheless it appears that in some cases experimental results can only be interpreted when non collisional damping phenomena are taken into consideration. (author) [French] Apres un apercu des etudes recemment publiees sur la sonde a resonance pour le diagnostic des plasmas, on rappelle l'essentiel de la theorie proposee par l'un de nous ou il est tenu compte explicitement de la geometrie du resonateur forme par le systeme sonde-gaine ionique-plasma dans l'approximation quasi-statique et du plasma froid. On indique quelques resultats nouveaux pouvant etre tires de cette theorie et on la confronte avec les donnees experimentales obtenues pour une sonde spherique placee dans un plasma de mercure en equilibre. Un tres bon accord quantitatif a ete constate, indiquant que la theorie est satisfaisante et justifiant les approximations faites dans celle-ci. Il apparait toutefois que certains resultats experimentaux ne peuvent etre interpretes qu'en tenant compte des phenomenes d'amortissement non collisionnels. (auteur)

  18. Self field electromagnetism and quantum phenomena

    Science.gov (United States)

    Schatten, Kenneth H.

    1994-07-01

    Quantum Electrodynamics (QED) has been extremely successful inits predictive capability for atomic phenomena. Thus the greatest hope for any alternative view is solely to mimic the predictive capability of quantum mechanics (QM), and perhaps its usefulness will lie in gaining a better understanding of microscopic phenomena. Many ?paradoxes? and problematic situations emerge in QED. To combat the QED problems, the field of Stochastics Electrodynamics (SE) emerged, wherein a random ?zero point radiation? is assumed to fill all of space in an attmept to explain quantum phenomena, without some of the paradoxical concerns. SE, however, has greater failings. One is that the electromagnetic field energy must be infinit eto work. We have examined a deterministic side branch of SE, ?self field? electrodynamics, which may overcome the probelms of SE. Self field electrodynamics (SFE) utilizes the chaotic nature of electromagnetic emissions, as charges lose energy near atomic dimensions, to try to understand and mimic quantum phenomena. These fields and charges can ?interact with themselves? in a non-linear fashion, and may thereby explain many quantum phenomena from a semi-classical viewpoint. Referred to as self fields, they have gone by other names in the literature: ?evanesccent radiation?, ?virtual photons?, and ?vacuum fluctuations?. Using self fields, we discuss the uncertainty principles, the Casimir effects, and the black-body radiation spectrum, diffraction and interference effects, Schrodinger's equation, Planck's constant, and the nature of the electron and how they might be understood in the present framework. No new theory could ever replace QED. The self field view (if correct) would, at best, only serve to provide some understanding of the processes by which strange quantum phenomena occur at the atomic level. We discuss possible areas where experiments might be employed to test SFE, and areas where future work may lie.

  19. Vector (two-dimensional) magnetic phenomena

    International Nuclear Information System (INIS)

    Enokizono, Masato

    2002-01-01

    In this paper, some interesting phenomena were described from the viewpoint of two-dimensional magnetic property, which is reworded with the vector magnetic property. It shows imperfection of conventional magnetic property and some interested phenomena were discovered, too. We found magnetic materials had the strong nonlinearity both magnitude and spatial phase due to the relationship between the magnetic field strength H-vector and the magnetic flux density B-vector. Therefore, magnetic properties should be defined as the vector relationship. Furthermore, the new Barukhausen signal was observed under rotating flux. (Author)

  20. Incorporating interfacial phenomena in solidification models

    Science.gov (United States)

    Beckermann, Christoph; Wang, Chao Yang

    1994-01-01

    A general methodology is available for the incorporation of microscopic interfacial phenomena in macroscopic solidification models that include diffusion and convection. The method is derived from a formal averaging procedure and a multiphase approach, and relies on the presence of interfacial integrals in the macroscopic transport equations. In a wider engineering context, these techniques are not new, but their application in the analysis and modeling of solidification processes has largely been overlooked. This article describes the techniques and demonstrates their utility in two examples in which microscopic interfacial phenomena are of great importance.

  1. Arcing phenomena in fusion devices workshop

    International Nuclear Information System (INIS)

    Clausing, R.E.

    1979-01-01

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included

  2. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    Silicone elastomers have been heavily investigated as candidates for dielectric elastomers and are as such almost ideal candidates with their inherent softness and compliance but they suffer from low dielectric permittivity. This shortcoming has been sought optimized by many means during recent...... years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we investigate the electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers. Two types...... of silicone elastomers are investigated and different types of breakdown are discussed. Furthermore the use of voltage stabilizers in silicone-based dielectric elastomers is investigated and discussed....

  3. Dissipative phenomena in condensed matter some applications

    CERN Document Server

    Dattagupta, Sushanta

    2004-01-01

    From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.

  4. Ordering phenomena in ABA triblock copolymer gels

    DEFF Research Database (Denmark)

    Reynders, K.; Mischenko, N.; Kleppinger, R.

    1997-01-01

    Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network). The lat......Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network...

  5. Third DOE natural phenomena hazards mitigation conference

    International Nuclear Information System (INIS)

    1991-01-01

    This conference on Natural Phenomena Hazards Mitigation has been organized into 15 presentation, panel, and poster sessions. The sessions included an overview of activities at DOE Headquarters; natural phenomena hazards tasks underway for DOE; two sessions on codes, standards, orders, criteria, and guidelines; two sessions on seismic hazards; equipment qualification; wind; PRA and margin assessments; modifications, retrofit, and restart; underground structures with a panel discussion; seismic analysis; seismic evaluation and design; and a poster session. Individual projects are processed separately for the data bases

  6. CP violating phenomena and theoretical results

    International Nuclear Information System (INIS)

    Grimus, W.

    1987-01-01

    An introduction to CP violating phenomena is given and the standard model and its most popular low energy extensions in this context are reviewed. The discussion comprises the minimal supersymmetric extension of the standard model, left-right symmetry, the standard model with more than one Higgs doublet and gauged horizontal symmetries. (Author)

  7. Collision and interaction phenomena - a historical outline

    International Nuclear Information System (INIS)

    Radmaneche, R.

    1977-09-01

    Collisions and interactions have become important for the description of matter. The author presents an outline which deals with elastic and inelastic collisions, with strong interactions, electromagnetic interactions, weak interactions and gravitational interactions. It is shown that the description of such processes has developed parallel with the understanding of matter and with the mechanism of the phenomena. Current and unsolved problems are mentioned

  8. Transport phenomena in materials processing---1990

    International Nuclear Information System (INIS)

    Bishop, B.J.; Lior, N.; Lavine, A.; Flik, M.; Karwe, M.V.; Bergman, T.L.; Beckermann, C.; Charmchi, M.

    1990-01-01

    The papers contained in this volume represent a wide range of current research interests in processes such as food and polymer processing, casting, welding, machining, laser cutting, and superconductor processing. This volume includes papers presented in four sessions: Heat Transfer in Materials Processing; Thermal Phenomena in Superconductor Processing; Heat Transfer in Food and Polymer Processing; Heat Transfer in CAsting and Welding

  9. Homoclinic phenomena in the gravitational collapse

    International Nuclear Information System (INIS)

    Koiller, J.; Mello Neto, J.R.T. de; Soares, I.D.

    1984-01-01

    A class of Bianchi IX cosmological models is shown to have chaotic gravitational collapse, due to Poincare's homoclinic phenomena. Such models can be programmed so that for any given positive integer N (N=infinity included) the universe undergoes N non-periodic oscillations (each oscillation requiring a long time) before collapsing. For N=infinity the universe undergoes periodic oscillations. (Author) [pt

  10. Novel experimentally observed phenomena in soft matter

    Indian Academy of Sciences (India)

    The resulting flow is non-Newtonian and is characterized by features such as shear rate-dependent viscosities and nonzero normal stresses. This article begins with an introduction to some unusual flow properties displayed by soft matter. Experiments that report a spectrum of novel phenomena exhibited by these materials, ...

  11. Some Phenomena on Negative Inversion Constructions

    Science.gov (United States)

    Sung, Tae-Soo

    2013-01-01

    We examine the characteristics of NDI (negative degree inversion) and its relation with other inversion phenomena such as SVI (subject-verb inversion) and SAI (subject-auxiliary inversion). The negative element in the NDI construction may be" not," a negative adverbial, or a negative verb. In this respect, NDI has similar licensing…

  12. Hyperchaotic phenomena in dynamic decision making

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Mosekilde, Erik; Sterman, John David

    1992-01-01

    of this article is to show how the decision making behavior of real people in simulated corporate environments can lead to chaotic, hyperchaotic and higher-order hyperchaotic phenomena. Characteristics features of these complicated forms of behavior are analyzed with particular emphasis on an interesting form...

  13. DOE natural phenomena hazards mitigation conference: proceedings

    International Nuclear Information System (INIS)

    1985-10-01

    The conference includes sessions which present an overview of DOE programs, available codes, standards and criteria, examples of designs and upgrades from the DOE complex, lessons learned from past natural phenomena, ground motion, seismic evaluation of equipment, and applications of probabilistic risk assessment techniques to DOE facilities. Separate abstracts have been prepared for individual papers

  14. Interface-induced phenomena in magnetism

    NARCIS (Netherlands)

    Hellman, Frances; Hoffmann, A.; Tserkovnyak, Yaroslav; Beach, Geoffrey S.D.; Fullerton, Eric E.; Leighton, Chris; Macdonald, Allan H.; Ralph, Daniel C.; Arena, Dario A.; Dürr, Hermann A.; Fischer, Peter; Grollier, Julie; Heremans, Joseph P.; Jungwirth, Tomas; Kimel, Alexey V.; Koopmans, B.; Krivorotov, Ilya N.; May, Steven J.; Petford-Long, Amanda K.; Rondinelli, James M.; Samarth, Nitin; Schuller, Ivan K.; Slavin, Andrei N.; Stiles, Mark D.; Tchernyshyov, Oleg; Thiaville, André; Zink, Barry L.

    2017-01-01

    This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on

  15. Analysis of induction phenomena in thermonuclear experiments

    International Nuclear Information System (INIS)

    Deeds, W.E.; Dodd, C.V.

    1976-01-01

    Many of the problems involving transients induced by changing currents in the large coils of thermonuclear machines are identical to those arising in nondestructive testing by eddy currents. There are three chief methods used for calculating such induction phenomena: analytical boundary-value solutions, relaxation or iteration techniques, and model experiments. Some of the results obtained by each of these methods are described below

  16. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an

  17. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Mateiu, Ramona Valentina; Skov, Anne Ladegaard

    2017-01-01

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al[2] and we investigate the electrical...

  18. Transport phenomena in strongly correlated Fermi liquids

    International Nuclear Information System (INIS)

    Kontani, Hiroshi

    2013-01-01

    Comprehensive overview. Written by an expert of this topic. Provides the reader with current developments in the field. In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, τ, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical point using a uniform approach. We also discuss spin related transport phenomena in strongly correlated systems. In many d- and f-electron systems, the spin current induced by the spin Hall effect is considerably greater because of the orbital degrees of freedom. This fact attracts much attention due to its potential application in spintronics. We discuss various novel charge, spin and heat transport phenomena in strongly correlated metals.

  19. Understanding the physics of changing mass phenomena

    NARCIS (Netherlands)

    Ellermeijer, A.L.

    2008-01-01

    Changing mass phenomena, like a falling chain or a bungee jumper, might give surprising results, even for experienced physicists. They have resulted in hot discussions in journals, in which for instance Physics professors claim the impossibility of an acceleration larger then g in case of a bungee

  20. Solar Phenomena Associated with "EIT Waves"

    Science.gov (United States)

    Biesecker, D. A.; Myers, D. C.; Thompson, B. J.; Hammer, D. M.; Vourlidas, A.

    2002-01-01

    In an effort to understand what an 'EIT wave' is and what its causes are, we have looked for correlations between the initiation of EIT waves and the occurrence of other solar phenomena. An EIT wave is a coronal disturbance, typically appearing as a diffuse brightening propagating across the Sun. A catalog of EIT waves, covering the period from 1997 March through 1998 June, was used in this study. For each EIT wave, the catalog gives the heliographic location and a rating for each wave, where the rating is determined by the reliability of the observations. Since EIT waves are transient, coronal phenomena, we have looked for correlations with other transient, coronal phenomena: X-ray flares, coronal mass ejections (CMEs), and metric type II radio bursts. An unambiguous correlation between EIT waves and CMEs has been found. The correlation of EIT waves with flares is significantly weaker, and EIT waves frequently are not accompanied by radio bursts. To search for trends in the data, proxies for each of these transient phenomena are examined. We also use the accumulated data to show the robustness of the catalog and to reveal biases that must be accounted for in this study.

  1. Theoretical foundations of electron spin resonance

    CERN Document Server

    Harriman, John E

    2013-01-01

    Theoretical Foundations of Electron Spin Resonance deals with the theoretical approach to electron paramagnetic resonance. The book discusses electron spin resonance in applications related to polyatomic, probably organic, free radicals in condensed phases. The book also focuses on essentially static phenomena, that is, the description and determination of stationary-state energy levels. The author reviews the Dirac theory of the electron in which a four-component wave function is responsible for the behavior of the electron. The author then connects this theory with the nonrelativistic wave f

  2. Contribution to the study of electron paramagnetic resonance and relaxation

    International Nuclear Information System (INIS)

    Theobald, Jean-Gerard

    1962-01-01

    This research thesis reports an experimental work which comprises the development of a very practical and very sensitive electron paramagnetic resonance spectrometer, and the use of this equipment for the study of irradiated substances and carbons. By studying electronic resonance signals by fast modulation of the magnetic field, the author studied phenomena of quick passage in electronic resonance, and showed that the study of these phenomena requires observation systems with a particularly large bandwidth. He reports the measurement of the line width of packs of spins of inhomogeneous lines by two different methods [fr

  3. Exotic Phenomena Searches at Hadron Colliders

    CERN Document Server

    INSPIRE-00305407

    2013-01-01

    This review presents a selection of the final results of searches for various exotic physics phenomena in proton-proton collisions at $\\sqrt{s}=7$ and 8~TeV delivered by the LHC and collected with the ATLAS and CMS detectors in 2011 (5 $fb^{-1}$) and in the first part of 2012 (4 $fb^{-1}$). Searches for large extra dimensions, gravitons, microscopic black holes, long-lived particles, dark matter, and leptoquarks are presented in this report. No sign of new physics beyond the standard model has been observed so far. In the majority of the cases these searches set the most stringent limits to date on the aforementioned new physics phenomena.

  4. Renormalization group theory of critical phenomena

    International Nuclear Information System (INIS)

    Menon, S.V.G.

    1995-01-01

    Renormalization group theory is a framework for describing those phenomena that involve a multitude of scales of variations of microscopic quantities. Systems in the vicinity of continuous phase transitions have spatial correlations at all length scales. The renormalization group theory and the pertinent background material are introduced and applied to some important problems in this monograph. The monograph begins with a historical survey of thermal phase transitions. The background material leading to the renormalization group theory is covered in the first three chapters. Then, the basic techniques of the theory are introduced and applied to magnetic critical phenomena in the next four chapters. The momentum space approach as well as the real space techniques are, thus, discussed in detail. Finally, brief outlines of applications of the theory to some of the related areas are presented in the last chapter. (author)

  5. Transport phenomena in strongly correlated Fermi liquids

    CERN Document Server

    Kontani, Hiroshi

    2013-01-01

    In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, \\tau, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical poi...

  6. Tunable caustic phenomena in electron wavefields

    Energy Technology Data Exchange (ETDEWEB)

    Tavabi, Amir Hossein, E-mail: a.tavabi@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Migunov, Vadim; Dwyer, Christian; Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy)

    2015-10-15

    Novel caustic phenomena, which contain fold, butterfly and elliptic umbilic catastrophes, are observed in defocused images of two approximately collinear oppositely biased metallic tips in a transmission electron microscope. The observed patterns depend sensitively on defocus, on the applied voltage between the tips and on their separation and lateral offset. Their main features are interpreted on the basis of a projected electrostatic potential model for the electron-optical phase shift. - Highlights: • Electron-optical caustics are observed in defocused images of biased metallic tips. • The caustics depend on defocus, on the bias between the tips and on their separation. • The setup offers the flexibility to study a wide variety of caustic phenomena.

  7. Basic transport phenomena in materials engineering

    CERN Document Server

    Iguchi, Manabu

    2014-01-01

    This book presents the basic theory and experimental techniques of transport phenomena in materials processing operations. Such fundamental knowledge is highly useful for researchers and engineers in the field to improve the efficiency of conventional processes or develop novel technology. Divided into four parts, the book comprises 11 chapters describing the principles of momentum transfer, heat transfer, and mass transfer in single phase and multiphase systems. Each chapter includes examples with solutions and exercises to facilitate students’ learning. Diagnostic problems are also provided at the end of each part to assess students’ comprehension of the material.  The book is aimed primarily at students in materials science and engineering. However, it can also serve as a useful reference text in chemical engineering as well as an introductory transport phenomena text in mechanical engineering. In addition, researchers and engineers engaged in materials processing operations will find the material use...

  8. Coherent topological phenomena in protein folding

    DEFF Research Database (Denmark)

    Bohr, Henrik; Brunak, Søren; Bohr, Jakob

    1997-01-01

    A theory is presented for coherent topological phenomena in protein dynamics with implications for protein folding and stability. We discuss the relationship to the writhing number used in knot diagrams of DNA. The winding state defines a long-range order along the backbone of a protein with long......-range excitations, `wring' modes, that play an important role in protein denaturation and stability. Energy can be pumped into these excitations, either thermally or by an external force....

  9. Workshop on Nonlinear Phenomena in Complex Systems

    CERN Document Server

    1989-01-01

    This book contains a thorough treatment of neural networks, cellular-automata and synergetics, in an attempt to provide three different approaches to nonlinear phenomena in complex systems. These topics are of major interest to physicists active in the fields of statistical mechanics and dynamical systems. They have been developed with a high degree of sophistication and include the refinements necessary to work with the complexity of real systems as well as the more recent research developments in these areas.

  10. Role of spinning electrons in paramagnetic phenomena

    International Nuclear Information System (INIS)

    Bose, D.M.

    1986-06-01

    An attempt is made to explain paramagnetic phenomena without assuming the orientation of a molecule or ion in a magnetic field. Only the spin angular momentum is assumed to be responsible. A derivative of the Gurie-Langevin law and the magnetic moments of ions are given as a function of the number of electrons in an inner, incomplete shell. An explanation of Gerlach's experiments with iron and nickel vapors is attempted. An explanation of magnetomechanical experiments with ferromagnetic elements is given

  11. From critical phenomena to gauge gields

    International Nuclear Information System (INIS)

    Le Bellac, M.

    1988-01-01

    In this book the author gives an introduction to the following questions: critical phenomena (Landau theory, renormalization group, two dimensional models); Perturbation theory and renormalization, scalar euclidian field (Feynman diagrams, Callan-Symanzik equations); Quantum theory of scalar fields (path integrals in quantum mechanics and statistical mechanics, green functions and S matrix, quantization of Klein-Gordon field); Gauge theories (quantization of Dirac field and electromagnetic field, quantum electrodynamics, non-abelian gauge theories) [fr

  12. Pseudogap phenomena in ultracold atomic Fermi gases

    OpenAIRE

    Chen, Qijin; Wang, Jibiao

    2014-01-01

    The pairing and superfluid phenomena in a two-component ultracold atomic Fermi gas is an analogue of Cooper pairing and superconductivity in an electron system, in particular, the high $T_c$ superconductors. Owing to the various tunable parameters that have been made accessible experimentally in recent years, atomic Fermi gases can be explored as a prototype or quantum simulator of superconductors. It is hoped that, utilizing such an analogy, the study of atomic Fermi gases may shed light to ...

  13. Occult Phenomena in Sherlock Holmes the Movie

    OpenAIRE

    NAMAZCARRA, CHRIESHER

    2014-01-01

    Keywords: Occult phenomena, Sherlock Holmes, movie. Lately, it is not difficult for people to find occult practices. There are many television programs and movie which air mystical programme aggressively to raise the rating and attract the viewers. A movie that raise occultism theme is Sherlock Holmes, the Movie. This movie tells about the struggle of detective Sherlock Holmes to fight the black magic power of Lord Blackwood.To carry out the study, the theories of Occultism such as the secrec...

  14. Investigation of oscillating airfoil shock phenomena

    OpenAIRE

    Giordano , Daniel; Fleeter , Sanford

    1992-01-01

    Fundamental experiments were performed in an unsteady flow water table facility to investigate and quantify the unsteady aerodynamics of a biconvex airfoil executing torsion mode oscillations at realistic reduced frequencies. A computer-based image enhancement system was used to measure the oscillating supersonic and transonic shock flow phenomena. By utilizing the hydraulic analogy to compare experimental results with a linear theoretical prediction, magnitude and phase relationships for the...

  15. Conformal field theories and critical phenomena

    International Nuclear Information System (INIS)

    Xu, Bowei

    1993-01-01

    In this article we present a brief review of the conformal symmetry and the two dimensional conformal quantum field theories. As concrete applications of the conformal theories to the critical phenomena in statistical systems, we calculate the value of central charge and the anomalous scale dimensions of the Z 2 symmetric quantum chain with boundary condition. The results are compatible with the prediction of the conformal field theories

  16. Status of neutron cross sections of transactinium isotopes in the resonance region - linear accelerator measurements

    International Nuclear Information System (INIS)

    James, G.D.

    1976-01-01

    A review of the status of transactinium isotope cross sections in the resonance region and of resolved resonance parameters is given by summarising the work submitted by fourteen contributors and also by highlighting other work where notable progress has been made in our knowledge of neutron resonance phenomena. (author)

  17. An interpretation of passive containment cooling phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Bum-Jin [Ministry of Science & Technology, Kyunggi-Do (Korea, Democratic People`s Republic of); Kang, Chang-Sun, [Seoul National Univ. (Korea, Democratic People`s Republic of)

    1995-09-01

    A simplified interpretation model for the cooling capability of the Westinghouse type PCCS is proposed in this paper. The PCCS domain was phenomenologically divided into 3 regions; water entrance effect region, asymptotic region, and air entrance effect region. The phenomena in the asymptotic region is focused in this paper. Due to the very large height to thickness ratio of the water film, the length of the asymptotic region is estimated to be over 90% of the whole domain. Using the analogy between heat and mass transfer phenomena in a turbulent situation, a new dependent variable combining temperature and vapor mass fraction was defined. The similarity between the PCCS phenomena, which contains the sensible and latent heat transfer, and the buoyant air flow on a vertical heated plate is derived. The modified buoyant coefficient and thermal conductivity were defined. Using these newly defined variable and coefficients, the modified correlation for the interfacial heat fluxes and the ratios of latent heat transfer to sensible heat transfer is established. To verify the accuracy of the correlation, the results of this study were compared with the results of other numerical analyses performed for the same configuration and they are well within the range of 15% difference.

  18. Quantum Chess: Making Quantum Phenomena Accessible

    Science.gov (United States)

    Cantwell, Christopher

    Quantum phenomena have remained largely inaccessible to the general public. There tends to be a scare factor associated with the word ``Quantum''. This is in large part due to the alien nature of phenomena such as superposition and entanglement. However, Quantum Computing is a very active area of research and one day we will have games that run on those quantum computers. Quantum phenomena such as superposition and entanglement will seem as normal as gravity. Is it possible to create such games today? Can we make games that are built on top of a realistic quantum simulation and introduce players of any background to quantum concepts in a fun and mentally stimulating way? One of the difficulties with any quantum simulation run on a classical computer is that the Hilbert space grows exponentially, making simulations of an appreciable size physically impossible due largely to memory restrictions. Here we will discuss the conception and development of Quantum Chess, and how to overcome some of the difficulties faced. We can then ask the question, ``What's next?'' What are some of the difficulties Quantum Chess still faces, and what is the future of quantum games?

  19. Thermal transport phenomena in nanoparticle suspensions

    International Nuclear Information System (INIS)

    Cardellini, Annalisa; Fasano, Matteo; Bozorg Bigdeli, Masoud; Chiavazzo, Eliodoro; Asinari, Pietro

    2016-01-01

    Nanoparticle suspensions in liquids have received great attention, as they may offer an approach to enhance thermophysical properties of base fluids. A good variety of applications in engineering and biomedicine has been investigated with the aim of exploiting the above potential. However, the multiscale nature of nanosuspensions raises several issues in defining a comprehensive modelling framework, incorporating relevant molecular details and much larger scale phenomena, such as particle aggregation and their dynamics. The objectives of the present topical review is to report and discuss the main heat and mass transport phenomena ruling macroscopic behaviour of nanosuspensions, arising from molecular details. Relevant experimental results are included and properly put in the context of recent observations and theoretical studies, which solved long-standing debates about thermophysical properties enhancement. Major transport phenomena are discussed and in-depth analysis is carried out for highlighting the role of geometrical (nanoparticle shape, size, aggregation, concentration), chemical (pH, surfactants, functionalization) and physical parameters (temperature, density). We finally overview several computational techniques available at different scales with the aim of drawing the attention on the need for truly multiscale predictive models. This may help the development of next-generation nanoparticle suspensions and their rational use in thermal applications. (topical review)

  20. Physical phenomena as sense determinate occurrences

    International Nuclear Information System (INIS)

    Sommer, H.J.

    2005-01-01

    In the view of El Naschie's E Infinity theory [Chaos, Solitons and Fractals 22 (2004) 495], our physical laws emerge from a chaotic underground, a 'Dirac-sea'. But we have no direct access from our observations to this chaotic world and this implies that the meaning of the correspondence between the phenomena we obtain by our cognition and their causal structures remains hidden to us. The fundamental process which produces our cognition is the 'constitution of sense'. A formal description of this process will be presented. We use Dempster Shafer's belief calculus to define 'belief' and motivate an Anticipation Principle: 'Put the measurements obtained from the world in such an order that the credibility of your forecasts will be maximized.' From this specification of the basic idea of what physical science ideally strives for, we are able to deduce a frame of reference for the formation of phenomena out of arbitrary sets of measurements. Reality is formed by these 'observable phenomena'. In this emerging reality, we recognize characteristic effects and principles of modern physics: Einstein's Postulate of Relativity, Entanglement, and the Quantum Zeno Effect. The presented view of reality is closely related to the ideas that had been presented hundred years ago by Ernst Mach and which recently J. Anandan generalized in his concept of a 'Relational Reality'

  1. Some aspects of geomagnetically conjugate phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Rycroft, M.J.

    1987-12-01

    Both charged particles and waves convey information about the thermosphere, ionosphere and magnetosphere from the Northern to the Southern Hemisphere and vice versa, along geomagnetic flux tubes.The interhemispheric travel time of electrons or ions, being dependent upon L-value , pitch angle and energy (which may lie between less than or equal to 1 eV and greater than or equal to 1 MeV) may be many hours, ranging down to less than or equal to 1 s. However, the one-hop propagation time for magnetohydrodynamic or whistler mode waves generally lies between 10/sup 2/s and 1 s. Such times, therefore, give the time scales of transient phenomena that are geomagnetically conjugate and of changes in steady-state plasma processes occurring in geomagnetically conjugate regions. Contrasting examples are presented of conjugate physical phenomena, obtained using satellite, rocket, aircraft and ground-based observations; the latter capitalise upon the rather rare disposition of land - rather than ocean - at each end of a geophysically interesting flux tube. Particular attention is paid to the interactions between whistler mode waves and energetic electrons. Geomagnetic, radio, optical and plasma observations, taken together with model computations, provide a wealth of knowledge on conjugate phenomena and their dependence on conditions in the solar wind, substorms, L-value, etc... Finally, some suggestions are made for future lines of research.

  2. A kinetic-MHD model for low frequency phenomena

    International Nuclear Information System (INIS)

    Cheng, C.Z.

    1991-07-01

    A hybrid kinetic-MHD model for describing low-frequency phenomena in high beta anisotropic plasmas that consist of two components: a low energy core component and an energetic component with low density. The kinetic-MHD model treats the low energy core component by magnetohydrodynamic (MHD) description, the energetic component by kinetic approach such as the gyrokinetic equation, and the coupling between the dynamics of these two components through plasma pressure in the momentum equation. The kinetic-MHD model optimizes both the physics contents and the theoretical efforts in studying low frequency MHD waves and transport phenomena in general magnetic field geometries, and can be easily modified to include the core plasma kinetic effects if necessary. It is applicable to any magnetized collisionless plasma system where the parallel electric field effects are negligibly small. In the linearized limit two coupled eigenmode equations for describing the coupling between the transverse Alfven type and the compressional Alfven type waves are derived. The eigenmode equations are identical to those derived from the full gyrokinetic equation in the low frequency limit and were previously analyzed both analytically nd numerically to obtain the eigenmode structure of the drift mirror instability which explains successfully the multi-satellite observation of antisymmetric field-aligned structure of the compressional magnetic field of Pc 5 waves in the magnetospheric ring current plasma. Finally, a quadratic form is derived to demonstrate the stability of the low-frequency transverse and compressional Alfven type instabilities in terms of the pressure anisotropy parameter τ and the magnetic field curvature-pressure gradient parameter. A procedure for determining the stability of a marginally stable MHD wave due to wave-particle resonances is also presented

  3. Multiquark Resonances

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties has been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of four tetraquarks, two of which had not been observed before. We mainly review the theoretical understanding of this sector of particle physics phenomenology and present some considerations attempting a coherent description of the so called X and Z resonances. The prominent problems plaguing theoretical models, like the absence of selection rules limiting the number of states predicted, motivate new directions in model building. Data are reviewed going through all of the observed resonances with particular attention to their common features and the purpose of providing a starting point to further research.

  4. Neuroaesthetic Resonance

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2013-01-01

    Neuroaesthetic Resonance emerged from a mature body of patient- centered gesture-control research investigating non-formal rehabilitation via ICT-enhanced-Art to question ‘Aesthetic Resonance’. Motivating participation, ludic engagement, and augmenting physical motion in non-formal (fun) treatment...... sessions are achieved via adaptive action-analyzed activities. These interactive virtual environments are designed to empower patients’ creative and/or playful expressions via digital feedback stimuli. Unconscious self- pushing of limits result from innate distractive mechanisms offered by the alternative...... the unencumbered motion-to-computer-generated activities - ‘Music Making’, ‘Painting’, ‘Robotic’ and ‘Video Game’ control. A focus of this position paper is to highlight how Aesthetic Resonance, in this context, relates to the growing body of research on Neuroaesthetics to evolve Neuroaesthetic Resonance....

  5. Baryon Resonances

    International Nuclear Information System (INIS)

    Oset, E.; Sarkar, S.; Sun Baoxi; Vicente Vacas, M.J.; Ramos, A.; Gonzalez, P.; Vijande, J.; Martinez Torres, A.; Khemchandani, K.

    2010-01-01

    In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the Λ(1405) resonance, as well as the prediction of one 1/2 + baryon state around 1920 MeV which might have been seen in the γp→K + Λ reaction.

  6. 996 RESONANCE November 2013

    Indian Academy of Sciences (India)

    IAS Admin

    996. RESONANCE. November 2013. Page 2. 997. RESONANCE. November 2013. Page 3. 998. RESONANCE. November 2013. Page 4. 999. RESONANCE. November 2013. Page 5. 1000. RESONANCE. November 2013. Page 6. 1001. RESONANCE. November 2013. Page 7. 1002. RESONANCE. November 2013 ...

  7. 817 RESONANCE September 2013

    Indian Academy of Sciences (India)

    IAS Admin

    817. RESONANCE ⎜ September 2013. Page 2. 818. RESONANCE ⎜ September 2013. Page 3. 819. RESONANCE ⎜ September 2013. Page 4. 820. RESONANCE ⎜ September 2013. Page 5. 821. RESONANCE ⎜ September 2013. Page 6. 822. RESONANCE ⎜ September 2013. Page 7. 823. RESONANCE ⎜ September ...

  8. 369 RESONANCE April 2016

    Indian Academy of Sciences (India)

    IAS Admin

    369. RESONANCE ⎜ April 2016. Page 2. 370. RESONANCE ⎜ April 2016. Page 3. 371. RESONANCE ⎜ April 2016. Page 4. 372. RESONANCE ⎜ April 2016. Page 5. 373. RESONANCE ⎜ April 2016. Page 6. 374. RESONANCE ⎜ April 2016. Page 7. 375. RESONANCE ⎜ April 2016.

  9. Synchrobetatron resonances

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. These resonances occur when the betatron oscillation wave numbers ν/sub x/ or ν/sub y/ and the synchrotron wave number ν/sub s/ satisfy the relation (ν/sub x,y/ - mν/sub s/) = 5, with m an integer denoting the m/sup th/ satellite. The main difference between SPEAR II and SPEAR I is the value of ν/sub s/, which in SPEAR II is approximately 0.04, an order of magnitude larger than in SPEAR I. An ad hoc meeting was held at the 1975 Particle Accelerator Conference, where details of the SPEAR II results were presented and various possible mechanisms for producing these resonances were discussed. Later, experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented

  10. Autostereogram resonators

    Science.gov (United States)

    Leavey, Sean; Rae, Katherine; Murray, Adam; Courtial, Johannes

    2012-09-01

    Autostereograms, or "Magic Eye" pictures, are repeating patterns designed to give the illusion of depth. Here we discuss optical resonators that create light patterns which, when viewed from a suitable position by a monocular observer, are autostereograms of the three-dimensional shape of one of the mirror surfaces.

  11. In vessel core melt progression phenomena

    International Nuclear Information System (INIS)

    Courtaud, M.

    1993-01-01

    For all light water reactor (LWR) accidents, including the so called severe accidents where core melt down can occur, it is necessary to determine the amount and characteristics of fission products released to the environment. For existing reactors this knowledge is used to evaluate the consequences and eventual emergency plans. But for future reactors safety authorities demand decrease risks and reactors designed in such a way that fission products are retained inside the containment, the last protective barrier. This requires improved understanding and knowledge of all accident sequences. In particular it is necessary to be able to describe the very complex phenomena occurring during in vessel core melt progression because they will determine the thermal and mechanical loads on the primary circuit and the timing of its rupture as well as the fission product source term. On the other hand, in case of vessel failure, knowledge of the physical and chemical state of the core melt will provide the initial conditions for analysis of ex-vessel core melt progression and phenomena threatening the containment. Finally a good understanding of in vessel phenomena will help to improve accident management procedures like Emergency Core Cooling System water injection, blowdown and flooding of the vessel well, with their possible adverse effects. Research and Development work on this subject was initiated a long time ago and is still in progress but now it must be intensified in order to meet the safety requirements of the next generation of reactors. Experiments, limited in scale, analysis of the TMI 2 accident which is a unique source of global information and engineering judgment are used to establish and assess physical models that can be implemented in computer codes for reactor accident analysis

  12. BWR core melt progression phenomena: Experimental analyses

    International Nuclear Information System (INIS)

    Ott, L.J.

    1992-01-01

    In the BWR Core Melt in Progression Phenomena Program, experimental results concerning severe fuel damage and core melt progression in BWR core geometry are used to evaluate existing models of the governing phenomena. These include control blade eutectic liquefaction and the subsequent relocation and attack on the channel box structure; oxidation heating and hydrogen generation; Zircaloy melting and relocation; and the continuing oxidation of zirconium with metallic blockage formation. Integral data have been obtained from the BWR DF-4 experiment in the ACRR and from BWR tests in the German CORA exreactor fuel-damage test facility. Additional integral data will be obtained from new CORA BWR test, the full-length FLHT-6 BWR test in the NRU test reactor, and the new program of exreactor experiments at Sandia National Laboratories (SNL) on metallic melt relocation and blockage formation. an essential part of this activity is interpretation and use of the results of the BWR tests. The Oak Ridge National Laboratory (ORNL) has developed experiment-specific models for analysis of the BWR experiments; to date, these models have permitted far more precise analyses of the conditions in these experiments than has previously been available. These analyses have provided a basis for more accurate interpretation of the phenomena that the experiments are intended to investigate. The results of posttest analyses of BWR experiments are discussed and significant findings from these analyses are explained. The ORNL control blade/canister models with materials interaction, relocation and blockage models are currently being implemented in SCDAP/RELAP5 as an optional structural component

  13. ACCIDENT PHENOMENA OF RISK IMPORTANCE PROJECT - Continued RESEARCH CONCERNING SEVERE ACCIDENT PHENOMENA AND MANAGEMENT IN Sweden

    International Nuclear Information System (INIS)

    Rolandson, S.; Mueller, F.; Loevenhielm, G.

    1997-01-01

    Since 1988 all reactors in Sweden have mitigating measures, such as filtered vents, implemented. In parallel with the work of implementing these measures, a cooperation effort (RAMA projects) between the Swedish utilities and the Nuclear Power Inspectorate was performed to acquire sufficient knowledge about severe accident research work. The on-going project has the name Accident Phenomena of Risk Importance 3. In this paper, we will give background information about severe accident management in Sweden. In the Accident Phenomena of Risk Importance 3 project we will focus on the work concerning coolability of melted core in lower plenum which is the main focus of the In-vessel Coolability Task Group within the Accident Phenomena of Risk Importance 3 project. The Accident Phenomena of Risk Importance 3 project has joined on international consortium and the in-vessel cooling experiments are performed by Fauske and Associates, Inc. in Burr Ridge, Illinois, United States America, Sweden also intends to do one separate experiment with one instrument penetration we have in Swedish/Finnish BWR's. Other parts of the Accident Phenomena of Risk Importance 3 project, such as support to level 2 studies, the research at Royal Institute of Technology and participation in international programs, such as Cooperative Severe Accident Research Program, Advanced Containment Experiments and PHEBUS will be briefly described in the paper

  14. Jets and large Psub(T) phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, D. S.

    1980-07-01

    Jets have been observed in hadron-hadron collisions and e/sup +/e/sup -/ annihilation at high energies. An attempt is made to explain the mechanism for the production of jets. The mechanism of quark-fragmentation is described with illustrations. Basic concepts and assumptions are used to study the distribution of quarks and gluons in a hadron. Quark and gluon decay distributions, and the transverse momentum distributions of quarks and gluons, Monte-Carlo methods in the study of jets, large Psub(T) phenomena in hadrons, QCD effects in hadronization of quark jets are discussed.

  15. Quenching phenomena in natural circulation loop

    International Nuclear Information System (INIS)

    Umekawa, Hisashi; Ozawa, Mamoru; Ishida, Naoki

    1995-01-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity

  16. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  17. General unifying features of controlled quantum phenomena

    International Nuclear Information System (INIS)

    Pechen, Alexander; Brif, Constantin; Wu, Rebing; Chakrabarti, Raj; Rabitz, Herschel

    2010-01-01

    Many proposals have been put forth for controlling quantum phenomena, including open-loop, adaptive feedback, and real-time feedback control. Each of these approaches has been viewed as operationally, and even physically, distinct from the others. This work shows that all such scenarios inherently share the same fundamental control features residing in the topology of the landscape relating the target physical observable to the applied controls. This unified foundation may provide a basis for development of hybrid control schemes that would combine the advantages of the existing approaches to achieve the best overall performance.

  18. Simple models of equilibrium and nonequilibrium phenomena

    International Nuclear Information System (INIS)

    Lebowitz, J.L.

    1987-01-01

    This volume consists of two chapters of particular interest to researchers in the field of statistical mechanics. The first chapter is based on the premise that the best way to understand the qualitative properties that characterize many-body (i.e. macroscopic) systems is to study 'a number of the more significant model systems which, at least in principle are susceptible of complete analysis'. The second chapter deals exclusively with nonequilibrium phenomena. It reviews the theory of fluctuations in open systems to which they have made important contributions. Simple but interesting model examples are emphasised

  19. Advances in modelling of condensation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Zaltsgendler, E. [Ontario Hydro Nuclear, Toronto (Canada); Hanna, B. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

    1997-07-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

  20. Cooperative phenomena in flows; Poster abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Loekseth, Trine (ed.)

    2011-05-15

    The objective of this 'Geilo School' was to bring together researchers with various interests and background including theoretical experimental physicists, material scientists and molecular biologists to identify and discuss areas where synergism between these disciplines may be most fruitfully applied to the study of various aspects of 'Cooperative phenomena in flows'. There were altogether 21 lecturers at the School with about 80 participants from 19 countries. This was the 21. Geilo School held biannually since the first one in I971. Reference to the earlier Geilo Schools 1971-2009 may be found here: http://www.ife.no/departments/physics/projects/geilo (Author)

  1. Current position on severe accident phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Henry, Robert E [Fauske and Associates, Inc., Burr Ridge, IL (United States)

    2004-07-01

    The phenomena addressed in this lecture are: in-vessel and ex-vessel hydrogen generation; in-vessel and in-containment natural circulation, steam explosions, direct containment heating, core-concrete interaction; debris coolability, containment strength/failure. The following events were modeled: axial and radial power distribution, two-phase level in the core, steam generation in covered section, decay heat generation, convection to gas, cladding oxidation, cold ballooning and rupture, natural circulation between the core and upper plenum, hydrogen generation, core meltdown, reflooding. Differences between PWR and BWR type reactors.

  2. Current position on severe accident phenomena

    International Nuclear Information System (INIS)

    Henry, Robert E.

    2004-01-01

    The phenomena addressed in this lecture are: in-vessel and ex-vessel hydrogen generation; in-vessel and in-containment natural circulation, steam explosions, direct containment heating, core-concrete interaction; debris coolability, containment strength/failure. The following events were modeled: axial and radial power distribution, two-phase level in the core, steam generation in covered section, decay heat generation, convection to gas, cladding oxidation, cold ballooning and rupture, natural circulation between the core and upper plenum, hydrogen generation, core meltdown, reflooding. Differences between PWR and BWR type reactors

  3. Cooperative phenomena in flows; Poster abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Loekseth, Trine [ed.

    2011-05-15

    The objective of this 'Geilo School' was to bring together researchers with various interests and background including theoretical experimental physicists, material scientists and molecular biologists to identify and discuss areas where synergism between these disciplines may be most fruitfully applied to the study of various aspects of 'Cooperative phenomena in flows'. There were altogether 21 lecturers at the School with about 80 participants from 19 countries. This was the 21. Geilo School held biannually since the first one in I971. Reference to the earlier Geilo Schools 1971-2009 may be found here: http://www.ife.no/departments/physics/projects/geilo (Author)

  4. Critical phenomena and renormalization group transformations

    International Nuclear Information System (INIS)

    Castellani, C.; Castro, C. di

    1980-01-01

    Our main goal is to guide the reader to find out the common rational behind the various renormalization procedures which have been proposed in the last ten years. In the first part of these lectures old arguments on universality and scaling will be briefly recalled. To our opinion these introductory remarks allow one to stress the physical origin of the two majore renormalization procedures, which have been used in the theory of critical phenomena: the Wilson and the field theoretic approach. All the general properties of a ''good'' renormalization transformation will also come out quite naturally. (author)

  5. Phenomena and parameters important to burnup credit

    International Nuclear Information System (INIS)

    Parks, C.V.; Dehart, M.D.; Wagner, J.C.

    2001-01-01

    Since the mid-1980s, a significant number of studies have been directed at understanding the phenomena and parameters important to implementation of burnup credit in out-of-reactor applications involving pressurized-water- reactor (PWR) spent fuel. The efforts directed at burnup credit involving boiling-water-reactor (BWR) spent fuel have been more limited. This paper reviews the knowledge and experience gained from work performed in the United States and other countries in the study of burnup credit. Relevant physics and analysis phenomenon are identified, and an assessment of their importance to burnup credit implementation for transport and dry cask storage is given. (author)

  6. Chalcogenides Metastability and Phase Change Phenomena

    CERN Document Server

    Kolobov, Alexander V

    2012-01-01

    A state-of-the-art description of metastability observed in chalcogenide alloys is presented with the accent on the underlying physics. A comparison is made between sulphur(selenium)-based chalcogenide glasses, where numerous photo-induced phenomena take place entirely within the amorphous phase, and tellurides where a reversible crystal-to-amorphous phase-change transformation is a major effect. Applications of metastability in devices¿optical memories and nonvolatile electronic phase-change random-access memories among others are discussed, including the latest trends. Background material essential for understanding current research in the field is also provided.

  7. Nanoscale and microscale phenomena fundamentals and applications

    CERN Document Server

    Khandekar, Sameer

    2015-01-01

    The book is an outcome of research work in the areas of nanotechnology, interfacial science, nano- and micro-fluidics and manufacturing, soft matter, and transport phenomena at nano- and micro-scales. The contributing authors represent prominent research groups from Indian Institute of Technology Bombay, Indian Institute of Technology Kanpur and Indian Institute of Science, Bangalore. The book has 13 chapters and the entire work presented in the chapters is based on research carried out over past three years. The chapters are designed with number of coloured illustrations, figures and tables. The book will be highly beneficial to academicians as well as industrial professionals working in the mentioned areas.

  8. Advances in modelling of condensation phenomena

    International Nuclear Information System (INIS)

    Liu, W.S.; Zaltsgendler, E.; Hanna, B.

    1997-01-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described

  9. Layered phenomena in the mesopause region

    Science.gov (United States)

    Plane, J. M. C.; Bailey, S. M.; Baumgarten, G.; Rapp, M.

    2015-05-01

    This special issue of the Journal of Atmospheric and Solar-Terrestrial Physics comprises a collection of papers which were mostly presented at the 11th Layered Phenomena in the Mesopause Region (LPMR) Workshop, held at the University of Leeds between 29th July 2013 and 1st August 2013. The topics covered at the workshop included atmospheric dynamics, mesospheric ice clouds, meteoric metal layers, meteoric smoke particles, and airglow layers. There was also a session on the potential of planned sub-orbital spacecraft for making measurements in the mesosphere and lower thermosphere (MLT).

  10. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  11. Quenching phenomena in natural circulation loop

    Energy Technology Data Exchange (ETDEWEB)

    Umekawa, Hisashi; Ozawa, Mamoru [Kansai Univ., Osaka (Japan); Ishida, Naoki [Daihatsu Motor Company, Osaka (Japan)

    1995-09-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  12. Critical Phenomena Associated with Boson Stars

    OpenAIRE

    Hawley, Scott H.; Choptuik, Matthew W.

    2001-01-01

    We present a brief synopsis of related work (gr-qc/0007039), describing a study of black hole threshold phenomena for a self-gravitating, massive complex scalar field in spherical symmetry. We construct Type I critical solutions dynamically by tuning a one-parameter family of initial data consisting of a boson star and a massless real scalar field, and numerically evolving this data. The resulting critical solutions appear to correspond to boson stars on the unstable branch, as we show via co...

  13. Hadron scattering, resonances, and QCD

    Science.gov (United States)

    Briceño, R. A.

    2016-11-01

    The non-perturbative nature of quantum chromodynamics (QCD) has historically left a gap in our understanding of the connection between the fundamental theory of the strong interactions and the rich structure of experimentally observed phenomena. For the simplest properties of stable hadrons, this is now circumvented with the use of lattice QCD (LQCD). In this talk I discuss a path towards a rigorous determination of few-hadron observables from LQCD. I illustrate the power of the methodology by presenting recently determined scattering amplitudes in the light-meson sector and their resonance content.

  14. Extended Smoluchowski models for interpreting relaxation phenomena in liquids

    International Nuclear Information System (INIS)

    Polimeno, A.; Frezzato, D.; Saielli, G.; Moro, G.J.; Nordio, P.L.

    1998-01-01

    Interpretation of the dynamical behaviour of single molecules or collective modes in liquids has been increasingly centered, in the last decade, on complex liquid systems, including ionic solutions, polymeric liquids, supercooled fluids and liquid crystals. This has been made necessary by the need of interpreting dynamical data obtained by advanced experiments, like optical Kerr effect, time dependent fluorescence shift experiments, two-dimensional Fourier-transform and high field electron spin resonance and scattering experiments like quasi-elastic neutron scattering. This communication is centered on the definition, treatment and application of several extended stochastic models, which have proved to be very effective tools for interpreting and rationalizing complex relaxation phenomena in liquids structures. First, applications of standard Fokker-Planck equations for the orientational relaxation of molecules in isotropic and ordered liquid phase are reviewed. In particular attention will be focused on the interpretation of neutron scattering in nematics. Next, an extended stochastic model is used to interpret time-domain resolved fluorescence emission experiments. A two-body stochastic model allows the theoretical interpretation of dynamical Stokes shift effects in fluorescence emission spectra, performed on probes in isotropic and ordered polar phases. Finally, for the case of isotropic fluids made of small rigid molecules, a very detailed model is considered, which includes as basic ingredients a Fokker-Planck description of the molecular vibrational motion and the slow diffusive motion of a persistent cage structure together with the decay processes related to the changing structure of the cage. (author)

  15. Compensatory recombination phenomena of neurological functions in central dysphagia patients

    Directory of Open Access Journals (Sweden)

    Xiao-dong Yuan

    2015-01-01

    Full Text Available We speculate that cortical reactions evoked by swallowing activity may be abnormal in patients with central infarction with dysphagia. The present study aimed to detect functional imaging features of cerebral cortex in central dysphagia patients by using blood oxygen level-dependent functional magnetic resonance imaging techniques. The results showed that when normal controls swallowed, primary motor cortex (BA4, insula (BA13, premotor cortex (BA6/8, supramarginal gyrus (BA40, and anterior cingulate cortex (BA24/32 were activated, and that the size of the activated areas were larger in the left hemisphere compared with the right. In recurrent cerebral infarction patients with central dysphagia, BA4, BA13, BA40 and BA6/8 areas were activated, while the degree of activation in BA24/32 was decreased. Additionally, more areas were activated, including posterior cingulate cortex (BA23/31, visual association cortex (BA18/19, primary auditory cortex (BA41 and parahippocampal cortex (BA36. Somatosensory association cortex (BA7 and left cerebellum in patients with recurrent cerebral infarction with central dysphagia were also activated. Experimental findings suggest that the cerebral cortex has obvious hemisphere lateralization in response to swallowing, and patients with recurrent cerebral infarction with central dysphagia show compensatory recombination phenomena of neurological functions. In rehabilitative treatment, using the favorite food of patients can stimulate swallowing through visual, auditory, and other nerve conduction pathways, thus promoting compensatory recombination of the central cortex functions.

  16. Migration and sorption phenomena in packaged foods.

    Science.gov (United States)

    Gnanasekharan, V; Floros, J D

    1997-10-01

    Rapidly developing analytical capabilities and continuously evolving stringent regulations have made food/package interactions a subject of intense research. This article focuses on: (1) the migration of package components such as oligomers and monomers, processing aids, additives, and residual reactants in to packaged foods, and (2) sorption of food components such as flavors, lipids, and moisture into packages. Principles of diffusion and thermodynamics are utilized to describe the mathematics of migration and sorption. Mathematical models are developed from first principles, and their applicability is illustrated using numerical simulations and published data. Simulations indicate that available models are system (polymer-penetrant) specific. Furthermore, some models best describe the early stages of migration/sorption, whereas others should be used for the late stages of these phenomena. Migration- and/or sorption-related problems with respect to glass, metal, paper-based and polymeric packaging materials are discussed, and their importance is illustrated using published examples. The effects of migrating and absorbed components on food safety, quality, and the environment are presented for various foods and packaging materials. The impact of currently popular packaging techniques such as microwavable, ovenable, and retortable packaging on migration and sorption are discussed with examples. Analytical techniques for investigating migration and sorption phenomena in food packaging are critically reviewed, with special emphasis on the use and characteristics of food-simulating liquids (FSLs). Finally, domestic and international regulations concerning migration in packaged foods, and their impact on food packaging is briefly presented.

  17. Study of catalytic phenomena in radiation chemistry

    International Nuclear Information System (INIS)

    Dran, J.C.

    1965-01-01

    Two phenomena have been studied: the action of γ rays from radio-cobalt on the adsorption and catalytic properties of ZnO and NiO in. relationship with the heterogeneous oxidation of CO, and the homogeneous catalysis by OsO 4 of the oxidation of various aqueous phase solutes by the same radiation. The prior irradiation of ZnO and of NiO does not modify their catalytic activity but generally increases the adsorption energy of -the gases CO and O 2 . The influence of the radiations appears to be connected with the presence of traces of water on ZnO and of an excess of oxygen on NiO. Osmium tetroxide which is not degraded by irradiation in acid solution, accelerates the radiolytic oxidation of certain compounds (Te IV , Pt 11 , As 111 ) in the presence of oxygen, as a result of its sensitizing effect on the oxidation by H 2 O 2 . In the case of phosphites on the other hand, OsO 4 has a protecting action under certain conditions of acidity and may suppress entirely the chain reaction which characterizes the oxidation of this solute byγ rays. A general mechanism is proposed for these phenomena. The rate constant for the OsO 4 + HO 2 reaction is calculated to be 5.7 x 10 5 l.mol -1 . sec -1 . (author) [fr

  18. WHC natural phenomena hazards mitigation implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    Conrads, T.J.

    1996-09-11

    Natural phenomena hazards (NPH) are unexpected acts of nature which pose a threat or danger to workers, the public or to the environment. Earthquakes, extreme winds (hurricane and tornado),snow, flooding, volcanic ashfall, and lightning strike are examples of NPH at Hanford. It is the policy of U.S. Department of Energy (DOE) to design, construct and operate DOE facilitiesso that workers, the public and the environment are protected from NPH and other hazards. During 1993 DOE, Richland Operations Office (RL) transmitted DOE Order 5480.28, ``Natural Phenomena Hazards Mitigation,`` to Westinghouse Hanford COmpany (WHC) for compliance. The Order includes rigorous new NPH criteria for the design of new DOE facilities as well as for the evaluation and upgrade of existing DOE facilities. In 1995 DOE issued Order 420.1, ``Facility Safety`` which contains the same NPH requirements and invokes the same applicable standards as Order 5480.28. It will supersede Order 5480.28 when an in-force date for Order 420.1 is established through contract revision. Activities will be planned and accomplished in four phases: Mobilization; Prioritization; Evaluation; and Upgrade. The basis for the graded approach is the designation of facilities/structures into one of five performance categories based upon safety function, mission and cost. This Implementation Plan develops the program for the Prioritization Phase, as well as an overall strategy for the implemention of DOE Order 5480.2B.

  19. Unsteady phenomena in the edge tone

    International Nuclear Information System (INIS)

    Paal, G.; Vaik, I.

    2007-01-01

    Despite its geometrical simplicity, the edge tone displays a remarkably complex behaviour. A plane jet oscillates around the wedge-shaped object with a relatively stable frequency and under certain circumstances emits an audible tone. This configuration plays a central role in the sound production of several wind instruments but occurs in industrial situations too. The flow exhibits various interesting nonlinear phenomena reported in the literature which are not entirely explained. In this paper, detailed high precision numerical simulations of the flow are reported under various conditions. Several phenomena are reproduced in agreement with the literature such as the existence of 'stages', the dependence of oscillation frequency on the outflow velocity and the orifice-edge distance within one stage, the pressure distribution on the edge surface, etc. A criterion for the appropriate time step for constant accuracy has been derived. The location of force action is surprisingly stable; it remains in a very narrow region of the wedge surface independently of the Reynolds number and the orifice-edge distance but it is much further behind the edge tip than reported in the literature. The various stages can coexist in different ways: jumping back and forth between stages or being superposed on each other. Regardless of the form, the first stage continues to be dominant even when the second and third stage appears. The question of disturbance propagation velocity and disturbance wavelength is also investigated. The development of higher harmonics of a single stage along the orifice-edge tip distance is presented

  20. Augmented Visual Experience of Simulated Solar Phenomena

    Science.gov (United States)

    Tucker, A. O., IV; Berardino, R. A.; Hahne, D.; Schreurs, B.; Fox, N. J.; Raouafi, N.

    2017-12-01

    The Parker Solar Probe (PSP) mission will explore the Sun's corona, studying solar wind, flares and coronal mass ejections. The effects of these phenomena can impact the technology that we use in ways that are not readily apparent, including affecting satellite communications and power grids. Determining the structure and dynamics of corona magnetic fields, tracing the flow of energy that heats the corona, and exploring dusty plasma near the Sun to understand its influence on solar wind and energetic particle formation requires a suite of sensors on board the PSP spacecraft that are engineered to observe specific phenomena. Using models of these sensors and simulated observational data, we can visualize what the PSP spacecraft will "see" during its multiple passes around the Sun. Augmented reality (AR) technologies enable convenient user access to massive data sets. We are developing an application that allows users to experience environmental data from the point of view of the PSP spacecraft in AR using the Microsoft HoloLens. Observational data, including imagery, magnetism, temperature, and density are visualized in 4D within the user's immediate environment. Our application provides an educational tool for comprehending the complex relationships of observational data, which aids in our understanding of the Sun.

  1. Syntactic Idioms and Precedent Phenomena: Intersection Zones

    Directory of Open Access Journals (Sweden)

    Hanna Sytar

    2016-08-01

    Full Text Available Background: One examined mainly structural and semantic features of syntactic idioms so far. The pragmatic dimension of these original units that are on the verge of syntax and phraseology, has not been highlighted properly in the scientific literature, so it needs theoretical understanding. The combination of syntactic idiom and phraseological phenomenon refers to the communication techniques impacting on message recipient. Purpose: to analyze the intersection zones of syntactic idioms and precedent phenomena. Results: Analysis of the collected factual material allows to distinguish two areas of interpenetration of syntactic idioms and precedent units: 1 construction of expression according to the phraseologized model, within which the position of variable component is filled by the precedent name or precedent expression; 2 the model of sentence itself is precedent, and lexical content does not comply with generally known one that does not affect on understanding of model content by recipient. With a combination of syntactic idiom and precedent phenomena speakers provide drawing of recipients’ attention, carry out a hidden influence on them, express their own attitude to the realities, so that perform phatic, manipulative and expressive-evaluative functions. The modifications and transformations of precedent expressions and names appeared to be regular in such interpenetrations. Discussion: The obtained results reflect the general trend towards transform (transformation, modification, variation, etc. of precedent, as well as phraseological units, and can be used for the analysis of patterns of their formation and modifications. Further research phase implies tracing patterns of syntactic idioms combination with other means of expressive syntax.

  2. Laboratory simulation of space plasma phenomena*

    Science.gov (United States)

    Amatucci, B.; Tejero, E. M.; Ganguli, G.; Blackwell, D.; Enloe, C. L.; Gillman, E.; Walker, D.; Gatling, G.

    2017-12-01

    Laboratory devices, such as the Naval Research Laboratory's Space Physics Simulation Chamber, are large-scale experiments dedicated to the creation of large-volume plasmas with parameters realistically scaled to those found in various regions of the near-Earth space plasma environment. Such devices make valuable contributions to the understanding of space plasmas by investigating phenomena under carefully controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. By working in collaboration with in situ experimentalists to create realistic conditions scaled to those found during the observations of interest, the microphysics responsible for the observed events can be investigated in detail not possible in space. To date, numerous investigations of phenomena such as plasma waves, wave-particle interactions, and particle energization have been successfully performed in the laboratory. In addition to investigations such as plasma wave and instability studies, the laboratory devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this presentation, we will describe several examples of the laboratory investigation of space plasma waves and instabilities and diagnostic development. *This work supported by the NRL Base Program.

  3. Modelling of thermohydraulic emergency core cooling phenomena

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Andreani, M.; Lewis, M.J.

    1990-10-01

    The codes used in the early seventies for safety analysis and licensing were based either on the homogeneous model of two-phase flow or on the so-called separate-flow models, which are mixture models accounting, however, for the difference in average velocity between the two phases. In both cases the behavior of the mixture is prescribed a priori as a function of local parameters such as the mass flux and the quality. The modern best-estimate codes used for analyzing LWR LOCA's and transients are often based on a two-fluid or 6-equation formulation of the conservation equations. In this case the conservation equations are written separately for each phase; the mixture is allowed to evolve on its own, governed by the interfacial exchanges of mass, momentum and energy between the phases. It is generally agreed that such relatively sophisticated 6-equation formulations of two-phase flow are necessary for the correct modelling of a number of phenomena and situations arising in LWR accidental situations. They are in particular indispensible for the analysis of stratified or countercurrent flows and of situations in which large departures from thermal and velocity equilibrium exist. This report will be devoted to a discussion of the need for, the capacity and the limitations of the two-phase flow models (with emphasis on the 6-equation formulations) in modelling these two-phase flow and heat transfer phenomena and/or different core cooling situations. 18 figs., 1 tab., 72 refs

  4. Shock Wave Diffraction Phenomena around Slotted Splitters

    Directory of Open Access Journals (Sweden)

    Francesca Gnani

    2015-01-01

    Full Text Available In the field of aerospace engineering, the study of the characteristics of vortical flows and their unsteady phenomena finds numerous engineering applications related to improvements in the design of tip devices, enhancement of combustor performance, and control of noise generation. A large amount of work has been carried out in the analysis of the shock wave diffraction around conventional geometries such as sharp and rounded corners, but the employment of splitters with lateral variation has hardly attracted the attention of researchers. The investigation of this phenomenon around two-dimensional wedges has allowed the understanding of the basic physical principles of the flow features. On the other hand, important aspects that appear in the third dimension due to the turbulent nature of the vortices are omitted. The lack of studies that use three-dimensional geometries has motivated the current work to experimentally investigate the evolution of the shock wave diffraction around two splitters with spike-shaped structures for Mach numbers of 1.31 and 1.59. Schlieren photography was used to obtain an insight into the sequential diffraction processes that take place in different planes. Interacting among them, these phenomena generate a complicated turbulent cloud with a vortical arrangement.

  5. Cavitation phenomena in extracorporeal microexplosion lithotripsy

    Science.gov (United States)

    Tomita, Y.; Obara, T.; Takayama, K.; Kuwahara, M.

    1994-09-01

    An experimental investigation was made of cavitation phenomena induced by underwater shock wave focusing applied to the extracorporeal microexplosion lithotripsy (microexplosion ESWL). Firstly an underwater microexplosion generated by detonation of a 10 mg silver azide pellet was studied and secondly underwater shock focusing and its induced cavitation phenomena were investgated. Underwater shock wave was focused by using a semi-ellipsoidal reflector in which a shock wave generated at the first focal point of the reflector was reflected and focused at the second focal point. It is found that an explosion product gas bubble did not produce any distinct rebound shocks. Meantime cavitation appeared after shock focusing at the second focal point where expansion waves originated at the exit of the reflector were simultaneously collected. A shock/bubble interaction is found to contribute not only to urinary tract stone disintegration but also tissue damage. The cavitation effect associated with the microexplosion ESWL was weaker in comparison with a spark discharge ESWL. The microexplosion ESWL is an effective method which can minimize the number of shock exposures hence decreasing tissue damage by conducting precise positioning of urinary tract stones.

  6. Study Of Severe Accident Phenomena In Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sugiyanto; Antariksawan; Anhar, R.; Arifal

    2001-01-01

    Several phenomena that occurred in the light water reactor type of nuclear power plant during severe accident were studied. The study was carried out based on the results of severe accident researches in various countries. In general, severe accident phenomena can be classified into in-vessel phenomena, retention in the reactor coolant system, and ex-vessel phenomena. In-vessel retention has been recommended as a severe accident management strategy

  7. Resonating Statements

    DEFF Research Database (Denmark)

    Hjelholt, Morten; Jensen, Tina Blegind

    2015-01-01

    IT projects are often complex arrangements of technological components, social actions, and organizational transformation that are difficult to manage in practice. This paper takes an analytical discourse perspective to explore the process of legitimizing IT projects. We introduce the concept...... of resonating statements to highlight how central actors navigate in various discourses over time. Particularly, the statements and actions of an IT project manager are portrayed to show how individuals can legitimize actions by connecting statements to historically produced discourses. The case study...... as part of a feedback loop to re-attach the localized IT project to the broader national discourse. The paper concludes with reflections on how to actively build on resonating statements as a strategic resource for legitimizing IT projects...

  8. Gravitoelectromagnetic resonances

    International Nuclear Information System (INIS)

    Tsagas, Christos G.

    2011-01-01

    The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations provide the natural stage for resonances to occur, gravitoelectromagnetic resonances have been investigated as a means of more efficient gravity-wave detection methods. In this report, we consider the coupling between the Weyl and the Maxwell fields on a Minkowski background, which also applies to astrophysical environments where gravity is weak, at the second perturbative level. We use covariant methods that describe gravitational waves via the transverse component of the shear, instead of pure-tensor metric perturbations. The aim is to calculate the properties of the electromagnetic signal, which emerges from the interaction of its linear counterpart with an incoming gravitational wave. Our analysis shows how the wavelength and the amplitude of the gravitationally driven electromagnetic wave vary with the initial conditions. More specifically, for certain initial data, the amplitude of the induced electromagnetic signal is found to diverge. Analogous, diverging, gravitoelectromagnetic resonances were also reported in cosmology. Given that, we extend our Minkowski space study to cosmology and discuss analogies and differences in the physics and in the phenomenology of the Weyl-Maxwell coupling between the aforementioned two physical environments.

  9. Multiscale Modeling of Mesoscale and Interfacial Phenomena

    Science.gov (United States)

    Petsev, Nikolai Dimitrov

    With rapidly emerging technologies that feature interfaces modified at the nanoscale, traditional macroscopic models are pushed to their limits to explain phenomena where molecular processes can play a key role. Often, such problems appear to defy explanation when treated with coarse-grained continuum models alone, yet remain prohibitively expensive from a molecular simulation perspective. A prominent example is surface nanobubbles: nanoscopic gaseous domains typically found on hydrophobic surfaces that have puzzled researchers for over two decades due to their unusually long lifetimes. We show how an entirely macroscopic, non-equilibrium model explains many of their anomalous properties, including their stability and abnormally small gas-side contact angles. From this purely transport perspective, we investigate how factors such as temperature and saturation affect nanobubbles, providing numerous experimentally testable predictions. However, recent work also emphasizes the relevance of molecular-scale phenomena that cannot be described in terms of bulk phases or pristine interfaces. This is true for nanobubbles as well, whose nanoscale heights may require molecular detail to capture the relevant physics, in particular near the bubble three-phase contact line. Therefore, there is a clear need for general ways to link molecular granularity and behavior with large-scale continuum models in the treatment of many interfacial problems. In light of this, we have developed a general set of simulation strategies that couple mesoscale particle-based continuum models to molecular regions simulated through conventional molecular dynamics (MD). In addition, we derived a transport model for binary mixtures that opens the possibility for a wide range of applications in biological and drug delivery problems, and is readily reconciled with our hybrid MD-continuum techniques. Approaches that couple multiple length scales for fluid mixtures are largely absent in the literature, and

  10. Magnetic resonance annual 1986

    International Nuclear Information System (INIS)

    Kressel, H.Y.

    1986-01-01

    This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging

  11. Real time animation of space plasma phenomena

    International Nuclear Information System (INIS)

    Jordan, K.F.; Greenstadt, E.W.

    1987-01-01

    In pursuit of real time animation of computer simulated space plasma phenomena, the code was rewritten for the Massively Parallel Processor (MPP). The program creates a dynamic representation of the global bowshock which is based on actual spacecraft data and designed for three dimensional graphic output. This output consists of time slice sequences which make up the frames of the animation. With the MPP, 16384, 512 or 4 frames can be calculated simultaneously depending upon which characteristic is being computed. The run time was greatly reduced which promotes the rapid sequence of images and makes real time animation a foreseeable goal. The addition of more complex phenomenology in the constructed computer images is now possible and work proceeds to generate these images

  12. Molecular dynamics simulation of laser shock phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, Ichirou [Japan Atomic Energy Research Inst., Kansai Research Establishment, Advanced Photon Research Center, Neyagawa, Osaka (Japan).

    2001-10-01

    Recently, ultrashort-pulse lasers with high peak power have been developed, and their application to materials processing is expected as a tool of precision microfabrication. When a high power laser irradiates, a shock wave propagates into the material and dislocations are generated. In this paper, laser shock phenomena of the metal were analyzed using the modified molecular dynamics method, which has been developed by Ohmura and Fukumoto. The main results obtained are summarized as follows: (1) The shock wave induced by the Gaussian beam irradiation propagates radially from the surface to the interior. (2) A lot of dislocations are generated at the solid-liquid interface by the propagation of a shock wave. (3) Some dislocations are moved instantaneously with the velocity of the longitudinal wave when the shock wave passes, and their velocity is not larger than the transverse velocity after the shock wave has passed. (author)

  13. Heat Transfer Phenomena of Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas [Forschungszentrum Karlsruhe, Institute for Nuclear and Energy Technologies, 76021 Karlsruhe (Germany)

    2008-07-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  14. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  15. PHENOMENA AND BASIC MACROECONOMIC INDICATORS FOR MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    PAULINA CATANA

    2010-01-01

    Full Text Available Macroeconomics is a separate discipline of the Economy that studies and analyzes the behaviour of economic aggregates and significant average, such as price level, national income, national income potential, the gap GDP, employment and unemployment of labour, investment and export of the whole economy. We can accuse to Macroeconomics that it deals also with the average price of all goods and services, not the prices of certain products. These aggregates result from economic behaviour of certain groups (governments, companies, consumers in the course of their activities on different markets. But why does it need Macroeconomics? Experts say that we need this separate discipline because there are certain forces that affect the broader economy globally, which can not be understood only by analyzing individual economic phenomena, individual products or markets.

  16. Transitional Phenomena on Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Wójcik Tadeusz M.

    2014-03-01

    Full Text Available One of the most significant problem with technology development is transferring of large heat fluxes, which requires constant heat transfer temperature (in the specified temperature range. This problem concern mainly the nuclear energetics, space technologies, military technologies and most of all electronics containing integrated circuits with very large scale of integrations. Intensive heat transfer and thermal energy storage are possible by the use of phase change materials (PCMs. In the paper there are presented preliminary results of research on the use of liquid-gas (L-G PCMs and solid-solid phase change materials (S-S PCMs. For L-G PCMs the boiling characteristics were determined by increasing and decreasing the heat flux, which for certain sets of structural parameters of the heating surface and the physical properties of the liquid induce a variety of forms of transitional phenomena. Thermal energy storage is much more effective when using PCMs than sensible heat.

  17. Characterizing critical phenomena via the Purcell effect

    Science.gov (United States)

    Silva Neto, M. B.; Szilard, D.; Rosa, F. S. S.; Farina, C.; Pinheiro, F. A.

    2017-12-01

    We investigate the role of phase transitions into the spontaneous-emission rate of a single quantum emitter embedded in a critical medium. Using a Landau-Ginzburg approach, we find that in the broken symmetry phase, the emission rate is reduced, or even suppressed, due to the photon mass generated by the Higgs mechanism. Remarkably, its sensitivity to the critical exponents of the phase transition allows for an optical determination of universality classes. When applied to the cases of superconductivity and superfluidity, we show that the Purcell effect also provides valuable information on spectroscopic and thermodynamic quantities, such as the size of the superconducting gap and the discontinuity in the specific heat at the transition. By unveiling that a deeper connection between the Purcell effect and phase transitions exists, we demonstrate that the former is an efficient optical probe of distinct critical phenomena and their associated observables.

  18. Extended RPA study of nuclear collective phenomena

    International Nuclear Information System (INIS)

    Drozdz, S.

    1987-01-01

    A fully microscopic study of nuclear collective phenomena is presented within the framework of an extended RPA which includes 1p-1h and 2p-2h excitations in a consistent way. This theory allows us to obtain a very realistic description of various excitation spectra. As a result, a strong evidence of correlation effects beyond mean-field theory emerges. The effective interaction used is a G-matrix derived from the meson-exchange potential. The extended theory introduces also additional correlations which screen the long-large part of the effective interaction. This effect significantly enhances the stability of the ground state against density fluctuations. In this connection a possible importance of relativistic effects is also discussed. 99 refs., 19 figs., 5 tabs. (author)

  19. Autistic phenomena in The Adventures of Pinocchio.

    Science.gov (United States)

    Smith, Adrian

    2017-04-01

    This paper seeks to demonstrate that the protagonist of Carlo Collodi's The Adventures of Pinocchio illustrates numerous autistic phenomena such as communication difficulties, sensory and perceptual distortions and mindblindness. While Pinocchio is viewed as a literary construct with contraindications of autism, it will be argued that his autistic traits are sufficient to suggest the possibility that Collodi had a partial intuition of the syndrome 60 years before it was identified by Leo Kanner. Approaching Collodi's text in this manner is taken as an opportunity to survey and reflect upon the psychoanalytic literature on autism and to position it in relation to contemporary theories from cognitive neuroscience. © 2017, The Society of Analytical Psychology.

  20. Discrete computational mechanics for stiff phenomena

    KAUST Repository

    Michels, Dominik L.

    2016-11-28

    Many natural phenomena which occur in the realm of visual computing and computational physics, like the dynamics of cloth, fibers, fluids, and solids as well as collision scenarios are described by stiff Hamiltonian equations of motion, i.e. differential equations whose solution spectra simultaneously contain extremely high and low frequencies. This usually impedes the development of physically accurate and at the same time efficient integration algorithms. We present a straightforward computationally oriented introduction to advanced concepts from classical mechanics. We provide an easy to understand step-by-step introduction from variational principles over the Euler-Lagrange formalism and the Legendre transformation to Hamiltonian mechanics. Based on such solid theoretical foundations, we study the underlying geometric structure of Hamiltonian systems as well as their discrete counterparts in order to develop sophisticated structure preserving integration algorithms to efficiently perform high fidelity simulations.

  1. Quantum field theory and critical phenomena

    CERN Document Server

    Zinn-Justin, Jean

    1996-01-01

    Over the last twenty years quantum field theory has become not only the framework for the discussion of all fundamental interactions except gravity, but also for the understanding of second-order phase transitions in statistical mechanics. This advanced text is based on graduate courses and summer schools given by the author over a number of years. It approaches the subject in terms of path and functional intergrals, adopting a Euclidean metric and using the language of partition and correlation functions. Renormalization and the renormalization group are examined, as are critical phenomena and the role of instantons. Changes for this edition 1. Extensive revision to eliminate a few bugs that had survived the second edition and (mainly) to improve the pedagogical presentation, as a result of experience gathered by lecturing. 2. Additional new topics; holomorphic or coherent state path integral; functional integral and representation of the field theory S-matrix in the holomorphic formalis; non-relativistic li...

  2. Experimental study of the natural circulation phenomena

    International Nuclear Information System (INIS)

    Sabundjian, Gaiane; Andrade, Delvonei Alves de; Umbehaun, Pedro E.; Torres, Walmir M.; Castro, Alfredo Jose Alvim de; Belchior Junior, Antonio; Rocha, Ricardo Takeshi Vieira da; Damy, Osvaldo Luiz de Almeida; Torres, Eduardo

    2006-01-01

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)

  3. Social phenomena from data analysis to models

    CERN Document Server

    Perra, Nicola

    2015-01-01

    This book focuses on the new possibilities and approaches to social modeling currently being made possible by an unprecedented variety of datasets generated by our interactions with modern technologies. This area has witnessed a veritable explosion of activity over the last few years, yielding many interesting and useful results. Our aim is to provide an overview of the state of the art in this area of research, merging an extremely heterogeneous array of datasets and models. Social Phenomena: From Data Analysis to Models is divided into two parts. Part I deals with modeling social behavior under normal conditions: How we live, travel, collaborate and interact with each other in our daily lives. Part II deals with societal behavior under exceptional conditions: Protests, armed insurgencies, terrorist attacks, and reactions to infectious diseases. This book offers an overview of one of the most fertile emerging fields bringing together practitioners from scientific communities as diverse as social sciences, p...

  4. Peridynamic Formulation for Coupled Thermoelectric Phenomena

    Directory of Open Access Journals (Sweden)

    Migbar Assefa

    2017-01-01

    Full Text Available Modeling of heat and electrical current flow simultaneously in thermoelectric convertor using classical theories do not consider the influence of defects in the material. This is because traditional methods are developed based on partial differential equations (PDEs and lead to infinite fluxes at the discontinuities. The usual way of solving such PDEs is by using numerical technique, like Finite Element Method (FEM. Although FEM is robust and versatile, it is not suitable to model evolving discontinuities. To avoid such shortcomings, we propose the concept of peridynamic theory to derive the balance of energy and charge equations in the coupled thermoelectric phenomena. Therefore, this paper presents the transport of heat and charge in thermoelectric material in the framework of peridynamic (PD theory. To illustrate the reliability of the PD formulation, numerical examples are presented and results are compared with those from literature, analytical solutions, or finite element solutions.

  5. Density turbulence and disruption phenomena in TEXTOR

    International Nuclear Information System (INIS)

    Waidmann, G.; Kuang, G.; Jadoul, M.

    1992-01-01

    Disruptive processes are observed in tokamak plasmas not only at the operating limits (density limit or q-limit) but can be found under a variety of experimental conditions. Large forces are exerted then on vessel components and support structures. The sudden release of stored plasma energy presents a serious erosion problem for the first wall already in the next generation of large tokamak machines. Strong energy losses from the plasma and an influx of impurities are already present in minor plasma disruptions which do not immediately lead to a plasma current termination. The rapid loss of energy confinement was investigated within the framework of a systematic study on plasma disruption phenomena in TEXTOR. (author) 4 refs., 4 figs

  6. Study of Travelling Interplanetary Phenomena Report

    Science.gov (United States)

    Dryer, Murray

    1987-09-01

    Scientific progress on the topic of energy, mass, and momentum transport from the Sun into the heliosphere is contingent upon interdisciplinary and international cooperative efforts on the part of many workers. Summarized here is a report of some highlights of research carried out during the SMY/SMA by the STIP (Study of Travelling Interplanetary Phenomena) Project that included solar and interplanetary scientists around the world. These highlights are concerned with coronal mass ejections from solar flares or erupting prominences (sometimes together); their large-scale consequences in interplanetary space (such as shocks and magnetic 'bubbles'); and energetic particles and their relationship to these large-scale structures. It is concluded that future progress is contingent upon similar international programs assisted by real-time (or near-real-time) warnings of solar activity by cooperating agencies along the lines experienced during the SMY/SMA.

  7. Cheshire cat phenomena and quarks in nuclei

    International Nuclear Information System (INIS)

    Rho, M.

    1986-11-01

    The notion of the ''Cheshire Cat'' principle in hadron structure is developed rigorously in (1+1) dimensions and approximately in (3+1) dimensions for up- and down-quark flavor systems. This phenomenon is invoked to address the issue as to whether or not direct quark-gluon signatures can be ''seen'' in low-energy nuclear phenomena. How addition of the third flavor -strangeness- can modify the Cheshire Cat property is discussed. It is proposed that one of the primary objectives of nuclear physics be to probe -and disturb- the ''vacuum'' of the strong interactions (QCD) and that for this purpose the chiral symmetry SU(3)xSU(3) can play a crucial role in normal and extreme conditions. As an illustration, kaon condensation at a density ρ>∼ 3ρ 0 is discussed in terms of a toy model and is related to ''cleansing'' of the quark condensates from the vacuum

  8. Implicit particle simulation of electromagnetic plasma phenomena

    International Nuclear Information System (INIS)

    Kamimura, T.; Montalvo, E.; Barnes, D.C.; Leboeuf, J.N.; Tajima, T.

    1986-11-01

    A direct method for the implicit particle simulation of electromagnetic phenomena in magnetized, multi-dimensional plasmas is developed. The method is second-order accurate for ωΔt < 1, with ω a characteristic frequency and time step Δt. Direct time integration of the implicit equations with simplified space differencing allows the consistent inclusion of finite particle size. Decentered time differencing of the Lorentz force permits the efficient simulation of strongly magnetized plasmas. A Fourier-space iterative technique for solving the implicit field corrector equation, based on the separation of plasma responses perpendicular and parallel to the magnetic field and longitudinal and transverse to the wavevector, is described. Wave propagation properties in a uniform plasma are in excellent agreement with theoretical expectations. Applications to collisionless tearing and coalescence instabilities further demonstrate the usefulness of the algorithm. (author)

  9. Hypnagogic and hypnopompic hallucinations: pathological phenomena?

    Science.gov (United States)

    Ohayon, M M; Priest, R G; Caulet, M; Guilleminault, C

    1996-10-01

    Hypnagogic and hypnopompic hallucinations are common in narcolepsy. However, the prevalence of these phenomena in the general population is uncertain. A representative community sample of 4972 people in the UK, aged 15-100, was interviewed by telephone (79.6% of those contacted). Interviews were performed by lay interviewers using a computerised system that guided the interviewer through the interview process. Thirty-seven per cent of the sample reported experiencing hypnagogic hallucinations and 12.5% reported hypnopompic hallucinations. Both types of hallucinations were significantly more common among subjects with symptoms of insomnia, excessive daytime sleepiness or mental disorders. According to this study, the prevalence of narcolepsy in the UK is 0.04%. Hypnagogic and hypnopompic hallucinations were much more common than expected, with a prevalence that far exceeds that which can be explained by the association with narcolepsy. Hypnopompic hallucinations may be a better indicator of narcolepsy than hypnagogic hallucinations in subjects reporting excessive daytime sleepiness.

  10. Nonmodal phenomena in differentially rotating dusty plasmas

    Science.gov (United States)

    Poedts, Stefaan; Rogava, Andria D.

    2000-10-01

    In this paper the foundation is layed for the nonmodal investigation of velocity shear induced phenomena in a differentially rotating flow of a dusty plasma. The simplest case of nonmagnetized flow is considered. It is shown that, together with the innate properties of the dusty plasma, the presence of differential rotation, Coriolis forces, and self-gravity casts a considerable richness on the nonmodal dynamics of linear perturbations in the flow. In particular: (i) dust-acoustic waves acquire the ability to extract energy from the mean flow and (ii) shear-induced, nonperiodic modes of collective plasma behavior-shear-dust-acoustic vortices-are generated. The presence of self-gravity and the nonzero Coriolis parameter (``epicyclic shaking'') makes these collective modes transiently unstable. .

  11. Nonmodal phenomena in differentially rotating dusty plasmas

    International Nuclear Information System (INIS)

    Poedts, Stefaan; Rogava, Andria D.

    2000-01-01

    In this paper the foundation is layed for the nonmodal investigation of velocity shear induced phenomena in a differentially rotating flow of a dusty plasma. The simplest case of nonmagnetized flow is considered. It is shown that, together with the innate properties of the dusty plasma, the presence of differential rotation, Coriolis forces, and self-gravity casts a considerable richness on the nonmodal dynamics of linear perturbations in the flow. In particular: (i) dust-acoustic waves acquire the ability to extract energy from the mean flow and (ii) shear-induced, nonperiodic modes of collective plasma behavior--shear-dust-acoustic vortices--are generated. The presence of self-gravity and the nonzero Coriolis parameter ('epicyclic shaking') makes these collective modes transiently unstable

  12. Noise-driven phenomena in hysteretic systems

    CERN Document Server

    Dimian, Mihai

    2014-01-01

    Noise-Driven Phenomena in Hysteretic Systems provides a general approach to nonlinear systems with hysteresis driven by noisy inputs, which leads to a unitary framework for the analysis of various stochastic aspects of hysteresis. This book includes integral, differential and algebraic models that are used to describe scalar and vector hysteretic nonlinearities originating from various areas of science and engineering. The universality of the authors approach is also reflected by the diversity of the models used to portray the input noise, from the classical Gaussian white noise to its impulsive forms, often encountered in economics and biological systems, and pink noise, ubiquitous in multi-stable electronic systems. The book is accompanied by HysterSoft© - a robust simulation environment designed to perform complex hysteresis modeling – that can be used by the reader to reproduce many of the results presented in the book as well as to research both disruptive and constructive effects of noise in hysteret...

  13. Pump instability phenomena generated by fluid forces

    Science.gov (United States)

    Gopalakrishnan, S.

    1985-01-01

    Rotor dynamic behavior of high energy centrifugal pumps is significantly affected by two types of fluid forces; one due to the hydraulic interaction of the impeller with the surrounding volute or diffuser and the other due to the effect of the wear rings. The available data on these forces is first reviewed. A simple one degree-of-freedom system containing these forces is analytically solved to exhibit the rotor dynamic effects. To illustrate the relative magnitude of these phenomena, an example of a multistage boiler feed pump is worked out. It is shown that the wear ring effects tend to suppress critical speed and postpone instability onset. But the volute-impeller forces tend to lower the critical speed and the instability onset speed. However, for typical boiler feed pumps under normal running clearances, the wear ring effects are much more significant than the destabilizing hydraulic interaction effects.

  14. Novel nuclear phenomena in quantum chromodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1987-08-01

    Many of the key issues in understanding quantum chromodynamics involve processes in nuclear targets at intermediate energies. A range of hadronic and nuclear phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction were discussed as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Several areas were also reviewed where there has been significant theoretical progress determining the form of hadron and nuclear wave functions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. A possible interpretation was also discussed of the large spin correlation A/sub NN/ in proton-proton scattering, and how relate this effect to an energy and angular dependence of color transparency in nuclei. 76 refs., 24 figs

  15. Nonlinear dynamics of spring softening and hardening in folded-mems comb drive resonators

    KAUST Repository

    Elshurafa, Amro M.; Khirallah, Kareem; Tawfik, Hani H.; Emira, Ahmed; Abdel Aziz, Ahmed K S; Sedky, Sherif M.

    2011-01-01

    This paper studies analytically and numerically the spring softening and hardening phenomena that occur in electrostatically actuated microelectromechanical systems comb drive resonators utilizing folded suspension beams. An analytical expression

  16. 1004 RESONANCE November 2013

    Indian Academy of Sciences (India)

    IAS Admin

    1004. RESONANCE │ November 2013. Page 2. 1005. RESONANCE │ November 2013. Page 3. 1006. RESONANCE │ November 2013. Page 4. 1007. RESONANCE │ November 2013. Page 5. 1008. RESONANCE │ November 2013. Page 6. 1009. RESONANCE │ November 2013. Page 7. 1010. RESONANCE ...

  17. Even order snake resonances

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1993-01-01

    We found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune shift of imperfection resonances, each snake resonance splits into two

  18. Report on the workshop on new directions in soft x-ray near-threshold phenomena

    International Nuclear Information System (INIS)

    Lindle, D.W.; Perera, R.C.C.

    1988-07-01

    The ''Workshop on New Directions in Soft X-Ray Near-Threshold Phenomena'' was held at the Asilomar Conference Center in Pacific Grove, CA on March 1--4, 1987. It was attended by 59 scientists from 8 countries, representing 27 institutions. Major funding for the meeting was donated by L-Division of the Lawrence Livermore National Laboratory, who hosted and organized two previous workshops on photoabsorption and scattering in the soft x-ray energy range. Additional funding was provided by the User's Group of the Advanced Light Source. The Workshop, as its name suggests, emphasized physical phenomena in atoms, molecules, and solids near inner-shell thresholds. Of particular interest were threshold ionization, post-collisional interaction, resonant photoemission and fluorescence, and multi-electron effects such as shake-up and shake-off. In these areas and others, special consideration was given to presenting recent discoveries and potential ''new directions'' for future work

  19. SEARCHING FOR ELECTRICAL PROPERTIES, PHENOMENA AND MECHANISMS IN THE CONSTRUCTION AND FUNCTION OF CHROMOSOMES

    Directory of Open Access Journals (Sweden)

    Ivan Kanev

    2013-03-01

    Full Text Available Our studies reveal previously unidentified electrical properties of chromosomes: (1 chromosomes are amazingly similar in construction and function to electrical transformers; (2 chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3 chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c mechanisms demonstrating heterochromatin to be electrically active and genetically important.

  20. APRI-6. Accident Phenomena of Risk Importance

    International Nuclear Information System (INIS)

    Garis, Ninos; Ljung, J

    2009-06-01

    Since the early 1980s, nuclear power utilities in Sweden and the Swedish Radiation Safety Authority (SSM) collaborate on the research in severe reactor accidents. In the beginning focus was mostly on strengthening protection against environmental impacts after a severe reactor accident, for example by develop systems for the filtered relief of the reactor containment. Since the early 90s, this focus has shifted to the phenomenological issues of risk-dominant significance. During the years 2006-2008, the partnership continued in the research project APRI-6. The aim was to show whether the solutions adopted in the Swedish strategy for incident management provides adequate protection for the environment. This is done by studying important phenomena in the core melt estimating the amount of radioactivity that can be released to the atmosphere in a severe accident. To achieve these objectives the research has included monitoring of international research on severe accidents and evaluation of results and continued support for research of severe accidents at the Royal Inst. of Technology (KTH) and Chalmers University. The follow-up of international research has promoted the exchange of knowledge and experience and has given access to a wealth of information on various phenomena relevant to events in severe accidents. The continued support to KTH has provided increased knowledge about the possibility of cooling the molten core in the reactor tank and the processes associated with coolability in the confinement and about steam explosions. Support for Chalmers has increased knowledge of the accident chemistry, mainly the behavior of iodine and ruthenium in the containment after an accident

  1. APRI-6. Accident Phenomena of Risk Importance

    Energy Technology Data Exchange (ETDEWEB)

    Garis, Ninos; Ljung, J [eds.; Swedish Radiation Safety Authority, Stockholm (Sweden); Agrenius, Lennart [ed.; Agrenius Ingenjoersbyraa AB, Stockholm (Sweden)

    2009-06-15

    Since the early 1980s, nuclear power utilities in Sweden and the Swedish Radiation Safety Authority (SSM) collaborate on the research in severe reactor accidents. In the beginning focus was mostly on strengthening protection against environmental impacts after a severe reactor accident, for example by develop systems for the filtered relief of the reactor containment. Since the early 90s, this focus has shifted to the phenomenological issues of risk-dominant significance. During the years 2006-2008, the partnership continued in the research project APRI-6. The aim was to show whether the solutions adopted in the Swedish strategy for incident management provides adequate protection for the environment. This is done by studying important phenomena in the core melt estimating the amount of radioactivity that can be released to the atmosphere in a severe accident. To achieve these objectives the research has included monitoring of international research on severe accidents and evaluation of results and continued support for research of severe accidents at the Royal Inst. of Technology (KTH) and Chalmers University. The follow-up of international research has promoted the exchange of knowledge and experience and has given access to a wealth of information on various phenomena relevant to events in severe accidents. The continued support to KTH has provided increased knowledge about the possibility of cooling the molten core in the reactor tank and the processes associated with coolability in the confinement and about steam explosions. Support for Chalmers has increased knowledge of the accident chemistry, mainly the behavior of iodine and ruthenium in the containment after an accident.

  2. Self-organization phenomena in plasma physics

    International Nuclear Information System (INIS)

    Sanduloviciu, M.; Popescu, S.

    2001-01-01

    The self-assembling in nature and laboratory of structures in systems away from thermodynamic equilibrium is one of the problems that mostly fascinates the scientists working in all branches of science. In this context a substantial progress has been obtained by investigating the appearance of spatial and spatiotemporal patterns in plasma. These experiments revealed the presence of a scenario of self-organization able to suggest an answer to the central problem of the 'Science of Complexity', why matter transits spontaneously from a disordered into an ordered state? Based on this scenario of self-organization we present arguments proving the possibility to explain the challenging problems of nonequilibrium physics in general. These problems refer to: (i) genuine origin of phase transitions observed in gaseous conductors and semiconductors; (ii) the elucidation of the role played by self-organization in the simulation of oscillations; (iii) the physical basis of anomalous transport of matter and energy with special reference to the possibilities of improving the economical performance of fusion devices; (iv) the possibility to use self-confined gaseous space charged configurations as an alternative to the magnetically confined plasma used at present in fusion devices. In other branches of sciences, as for instance in Biology, the self-organization scenario reveals a new insight into a mechanism able to explain the appearance of the simplest possible space charge configuration able to evolve, under suitable conditions, into prebiotic structures. Referring to phenomena observed in nature, the same self-organization scenario suggests plausible answers to the appearance of ball lightening but also to the origin of the flickering phenomena observed in the light emission of the Sun and stars. For theory the described self-organization scenario offers a new physical basis for many problems of nonlinear science not solved yet and also a new model for the so-called 'self

  3. Meteorological phenomena in Western classical orchestral music

    Science.gov (United States)

    Williams, P. D.; Aplin, K. L.

    2012-12-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London. Of course, an important part of what we see and hear is not only the people with whom we interact, but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant, because we are exposed to it directly and daily. The weather was a great source of inspiration for Monet, Constable, and Turner, who are known for their scientifically accurate paintings of the skies. But to what extent does weather inspire composers? The authors of this presentation, who are atmospheric scientists by day but amateur classical musicians by night, have been contemplating this question. We have built a systematic musical database, which has allowed us to catalogue and analyze the frequencies with which weather is depicted in a sample of classical orchestral music. The depictions vary from explicit mimicry using traditional and specialized orchestral instruments, through to subtle suggestions. We have found that composers are generally influenced by their own environment in the type of weather they choose to represent. As befits the national stereotype, British composers seem disproportionately keen to depict the UK's variable weather patterns and stormy coastline. Reference: Aplin KL and Williams PD (2011) Meteorological phenomena in Western classical orchestral music. Weather, 66(11), pp 300-306. doi:10.1002/wea.765

  4. TRANSIENT LUNAR PHENOMENA: REGULARITY AND REALITY

    International Nuclear Information System (INIS)

    Crotts, Arlin P. S.

    2009-01-01

    Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled, and even their existence as a coherent phenomenon is controversial. Nonetheless, TLP data show regularities in the observations; a key question is whether this structure is imposed by processes tied to the lunar surface, or by terrestrial atmospheric or human observer effects. I interrogate an extensive catalog of TLPs to gauge how human factors determine the distribution of TLP reports. The sample is grouped according to variables which should produce differing results if determining factors involve humans, and not reflecting phenomena tied to the lunar surface. Features dependent on human factors can then be excluded. Regardless of how the sample is split, the results are similar: ∼50% of reports originate from near Aristarchus, ∼16% from Plato, ∼6% from recent, major impacts (Copernicus, Kepler, Tycho, and Aristarchus), plus several at Grimaldi. Mare Crisium produces a robust signal in some cases (however, Crisium is too large for a 'feature' as defined). TLP count consistency for these features indicates that ∼80% of these may be real. Some commonly reported sites disappear from the robust averages, including Alphonsus, Ross D, and Gassendi. These reports begin almost exclusively after 1955, when TLPs became widely known and many more (and inexperienced) observers searched for TLPs. In a companion paper, we compare the spatial distribution of robust TLP sites to transient outgassing (seen by Apollo and Lunar Prospector instruments). To a high confidence, robust TLP sites and those of lunar outgassing correlate strongly, further arguing for the reality of TLPs.

  5. Resonant learning

    DEFF Research Database (Denmark)

    Lindvang, Charlotte

    2013-01-01

    -experience and personal therapy in training, first and foremost from the students’ perspective. The author focuses on presenting the qualitative part of her research which namely addresses the students’ experiences. Semi-structured qualitative interviews and qualitative music analyses were conducted, using a hermeneutic...... approach. The informants were nine music therapy students from Aalborg University, enrolled in the fifth year of their Master’s degree training programme. They were asked to bring a recording of an improvisation of their own choice to the interview. The qualitative data collection of text and music......The article presents a part of the authors PhD-study in music therapy about self-experiential training and the development of music therapeutic competencies. One of the purposes of the study was to explore and generate understanding and insight into the phenomena of learning through self...

  6. Nonlinear plasma waves excited near resonance

    International Nuclear Information System (INIS)

    Cohen, B.I.; Kaufman, A.N.

    1977-01-01

    The nonlinear resonant response of a uniform plasma to an external plane-wave field is formulated in terms of the mismatch Δ/sub n l/ between the driving frequency and the time-dependent, complex, nonlinear normal mode frequency at the driving wavenumber. This formalism is applied to computer simulations of this process, yielding a deduced nonlinear frequency shift. The time dependence of the nonlinear phenomena, at frequency Δ/sub n l/ and at the bounce frequency of the resonant particles, is analyzed. The interdependence of the nonlinear features is described by means of energy and momentum relations

  7. Optical resonance and two-level atoms

    CERN Document Server

    Allen, L

    1987-01-01

    ""Coherent and lucid…a valuable summary of a subject to which [the authors] have made significant contributions by their own research."" - Contemporary PhysicsOffering an admirably clear account of the basic principles behind all quantum optical resonance phenomena, and hailed as a valuable contribution to the literature of nonlinear optics, this distinguished work provides graduate students and research physicists probing fields such as laser physics, quantum optics, nonlinear optics, quantum electronics, and resonance optics an ideal introduction to the study of the interaction of electroma

  8. Simulation of Magnetic Phenomena at Realistic Interfaces

    KAUST Repository

    Grytsyuk, Sergiy

    2016-02-04

    In modern technology exciting developments are related to the ability to understand and control interfaces. Particularly, magnetic interfaces revealing spindependent electron transport are of great interest for modern spintronic devices, such as random access memories and logic devices. From the technological point of view, spintronic devices based on magnetic interfaces enable manipulation of the magnetism via an electric field. Such ability is a result of the different quantum effects arising from the magnetic interfaces (for example, spin transfer torque or spin-orbit torque) and it can reduce the energy consumption as compared to the traditional semiconductor electronic devices. Despite many appealing characteristics of these materials, fundamental understanding of their microscopic properties and related phenomena needs to be established by thorough investigation. In this work we implement first principles calculations in order to study the structural, electric, and magnetic properties as well as related phenomena of two types of interfaces with large potential in spintronic applications: 1) interfaces between antiferromagnetic 3d-metal-oxides and ferromagnetic 3d-metals and 2) interfaces between non-magnetic 5d(4d)- and ferromagnetic 3d-metals. A major difficulty in studying such interfaces theoretically is the typically large lattice mismatch. By employing supercells with Moir e patterns, we eliminate the artificial strain that leads to doubtful results and are able to describe the dependence of the atomic density at the interfaces on the component materials and their thicknesses. After establishing understanding about the interface structures, we investigate the electronic and magnetic properties. A Moir e supercell with transition layer is found to reproduce the main experimental findings and thus turns out to be the appropriate model for simulating magnetic misfit interfaces. In addition, we systematically study the magnetic anisotropy and Rashba band

  9. Living matter: the "lunar eclipse" phenomena.

    Science.gov (United States)

    Korpan, Nikolai N

    2010-01-01

    The present investigations describe a unique phenomenon, namely the phenomenon of the "lunar eclipse", which has been observed and discovered by the author in living substance during the freeze-thawing processes in vivo using temperatures of various intensities and its cryosurgical response in animal experiment. Similar phenomena author has observed in nature, namely the total lunar eclipse and total solar eclipse. In this experimental study 76 animals (mongrel dogs) were investigated. A disc cryogenic probe was placed on the pancreas after the laparotomy. For cryosurgical exposure a temperature range of -40 degrees C, -80 degrees C, -120 degrees C and -180 degrees C was selected in contact with pancreas parenchyma. The freeze-thaw cycle was monitored by intraoperative ultrasound before, during and after cryosurgery. Each cryolesion was observed for one hour after thawing intraoperatively. Immediately after freezing, during the thawing process, the snow-white pancreas parenchyma, frozen hard to an ice block and resembling a full moon with a sharp demarcation line, gradually assumed a ruby-red shade and a hemispherical shape as it grew in size depend on reconstruction vascular circulation from the periphery to the center. This snow-white cryogenic lesion dissolved in the same manner in all animal tissues. The "lunar eclipse" phenomenon contributes to a fundamental understanding of the mechanisms of biological tissue damage during low temperature exposure in cryoscience and cryomedicine. Properties of the pancreas parenchyma response during the phenomenon of the "lunar eclipse" provide important insights into the mechanisms of damage and the formation of cryogenic lesion immediately after thawing in cryosurgery. Vascular changes and circulatory stagnation are commonly considered to be the main mechanism of biological tissue injury during low temperature exposure. The phenomenon of the "lunar eclipse" suggests that cryosurgery is the first surgical technique to use

  10. Pathways toward understanding Macroscopic Quantum Phenomena

    International Nuclear Information System (INIS)

    Hu, B L; Subaşi, Y

    2013-01-01

    Macroscopic quantum phenomena refer to quantum features in objects of 'large' sizes, systems with many components or degrees of freedom, organized in some ways where they can be identified as macroscopic objects. This emerging field is ushered in by several categories of definitive experiments in superconductivity, electromechanical systems, Bose-Einstein condensates and others. Yet this new field which is rich in open issues at the foundation of quantum and statistical physics remains little explored theoretically (with the important exception of the work of A J Leggett [1], while touched upon or implied by several groups of authors represented in this conference. Our attitude differs in that we believe in the full validity of quantum mechanics stretching from the testable micro to meso scales, with no need for the introduction of new laws of physics.) This talk summarizes our thoughts in attempting a systematic investigation into some key foundational issues of quantum macroscopic phenomena, with the goal of ultimately revealing or building a viable theoretical framework. Three major themes discussed in three intended essays are the large N expansion [2], the correlation hierarchy [3] and quantum entanglement [4]. We give a sketch of the first two themes and then discuss several key issues in the consideration of macro and quantum, namely, a) recognition that there exist many levels of structure in a composite body and only by judicious choice of an appropriate set of collective variables can one give the best description of the dynamics of a specific level of structure. Capturing the quantum features of a macroscopic object is greatly facilitated by the existence and functioning of these collective variables; b) quantum entanglement, an exclusively quantum feature [5], is known to persist to high temperatures [6] and large scales [7] under certain conditions, and may actually decrease with increased connectivity in a quantum network [8]. We use entanglement as a

  11. Many-electron phenomena in the ionization of ions

    International Nuclear Information System (INIS)

    Mueller, A.

    2004-01-01

    Full text: Single and multiple ionization in ion-atom collisions involve a multitude of complex interactions between the electrons and nuclei of projectile and target. Some of the complexity is avoided in studies of fast collisions when the impulse approximation can be applied and the electrons can be described as independent quasi-free particles with a known momentum distribution. For the detailed investigation of ionization mechanisms that can occur in fast ion-atom collisions, it is illuminating to consider collisions of ions (or atoms) and really free electrons with a narrow energy spread. High energy resolution in electron-ion collision studies provides access to individual, possibly even state-selective, reaction pathways. Even in the simple electron-ion collision system (simple compared with the initial ion-atom problem) single and multiple ionization still involve a multitude of complex mechanisms. Besides the direct removal of one or several electrons from the target by electron impact, resonant and non-resonant formation of intermediate multiply excited states which subsequently decay by electron emission is important in single and multiple ionization of ions and atoms. Direct ionization proceeds via one-step or multi-step knock-off mechanisms which can partly be disentangled by studying effects of different projectile species. The role of multiply excited states in the ionization can be experimentally studied in great detail by a further reduction of the initial ion-atom problem. Multiply excited states of atoms and ions can be selectively populated by photon-ion interactions making use of the potential for extreme energy resolution made available at modern synchrotron radiation sources. In the review talk, examples of studies on single and multiple ionization in electron-ion collisions will be discussed in some detail. Electron-ion collision experiments will also be compared with photon-ion interaction studies. Many-electron phenomena have been observed

  12. Spin-transfer phenomena in layered magnetic structures: Physical phenomena and materials aspects

    International Nuclear Information System (INIS)

    Gruenberg, P.; Buergler, D.E.; Dassow, H.; Rata, A.D.; Schneider, C.M.

    2007-01-01

    During the past 20 years, layered structures consisting of ferromagnetic layers and spacers of various material classes with a thickness of only a few nanometers have revealed a variety of exciting and potentially very useful phenomena not present in bulk material. Representing distinct manifestations of spin-transfer processes, these phenomena may be categorized into interlayer exchange coupling (IEC), giant magnetoresistance (GMR), tunneling magnetoresistance (TMR), and the more recently discovered spin-transfer torque effect leading to current-induced magnetization switching (CIMS) and current-driven magnetization dynamics. These phenomena clearly confer novel material properties on magnetic layered structures with respect to the (magneto-)transport and the magnetostatic as well as magnetodynamic behavior. Here, we will first concentrate on the less well understood aspects of IEC across insulating and semiconducting interlayers and relate the observations to TMR in the corresponding structures. In this context, we will also discuss more recent advances in TMR due to the use of electrodes made from Heusler alloys and the realization of coherent tunneling in epitaxial magnetic tunneling junctions. Finally, we will review our results on CIMS in epitaxial magnetic nanostructures showing that normal and inverse CIMS can occur simultaneously in a single nanopillar device. In all cases discussed, material issues play a major role in the detailed understanding of the spin-transfer effects, in particular in those systems that yield the largest effects and are thus of utmost interest for applications

  13. APRI - Accident Phenomena of Risk Importance. Final Report; APRI - Accident Phenomena of Risk Importance. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Frid, W. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Hammar, L.; Soederman, E. [ES-konsult, Stockholm (Sweden)

    1996-12-01

    The APRI-project started in 1992 with participation of the Swedish Nuclear Power Inspectorate (SKI) and the Swedish utilities. The Finnish utility TVO joined the project in 1993. The aim of the project has been to work with phenomenological questions in severe accidents, concentrating on the risk-dominating issues. The work is reported in separate sub-project reports, the present is the final report of the methodological studies as well as a final report for the total project. The research has led to clarifications of the risk complex, and ameliorated the basis for advanced probabilistic safety analyses, specially for the emission risks (PSA level 2) which are being studied at the Swedish plants. A new method has been tried for analysis of complicated accident courses, giving a possibility for systematic evaluation of the impact of different important phenomena (e.g. melt-through, high pressure melt-through with direct heating of the containment atmosphere, steam explosions). In this method, the phenomena are looked upon as top events of a `phenomena-tree`, illustrating how various conditions must be met before the top-event can happen. This method has been useful, in particular for applying `expert estimates`. 47 refs.

  14. Dictionary of astronomy, space, and atmospheric phenomena

    International Nuclear Information System (INIS)

    Tver, D.F.; Motz, L.; Hartmann, W.K.

    1979-01-01

    This concise and up-to-date compendium features descriptions and definitions of terms, techniques and equipment relating to celestial phenomena. It explains the latest concepts in space exploration, planetary research, stellar astronomy, and meteorological science. The authors explore the general configurations of star groups, galaxy types, stars, and other small bodies in the solar system, including such important facts as magnitude of each and distance from Earth. They describe the brightest stars one by one. Vital data provided by the Viking, Mariner, and Pioneer space probes, the Voyager flights past Jupiter and its moons, and the Apollo landings are clearly presented and explained. New concepts in stellar astronomy such as quasars, neutron stars (pulsars), and black holes are precisely defined. Also included are discussions of meteor showers and the important rock types found on each planet; definitions of meteorological terms, ad astronomical equipment including telescopes, eyepieces and their accessories, the Golay cell, canopus sensor, filar micrometer, and more. Charts aid in identifying and locating stars and planets, and helpful reference tables list the location of the major celestial bodies - asteroids, constellations, the nearest stars, the brightest stars, interesting double and variable stars and cluters. Also included is the Meisser catalog of the coordinates and magnitudes for more than 100 celestial objects

  15. Attractors, bifurcations, & chaos nonlinear phenomena in economics

    CERN Document Server

    Puu, Tönu

    2003-01-01

    The present book relies on various editions of my earlier book "Nonlinear Economic Dynamics", first published in 1989 in the Springer series "Lecture Notes in Economics and Mathematical Systems", and republished in three more, successively revised and expanded editions, as a Springer monograph, in 1991, 1993, and 1997, and in a Russian translation as "Nelineynaia Economicheskaia Dinamica". The first three editions were focused on applications. The last was differ­ ent, as it also included some chapters with mathematical background mate­ rial -ordinary differential equations and iterated maps -so as to make the book self-contained and suitable as a textbook for economics students of dynamical systems. To the same pedagogical purpose, the number of illus­ trations were expanded. The book published in 2000, with the title "A ttractors, Bifurcations, and Chaos -Nonlinear Phenomena in Economics", was so much changed, that the author felt it reasonable to give it a new title. There were two new math­ ematics ch...

  16. Mixing, ergodicity and slow relaxation phenomena

    Science.gov (United States)

    Costa, I. V. L.; Vainstein, M. H.; Lapas, L. C.; Batista, A. A.; Oliveira, F. A.

    2006-11-01

    Investigations on diffusion in systems with memory [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] have established a hierarchical connection between mixing, ergodicity, and the fluctuation-dissipation theorem (FDT). This hierarchy means that ergodicity is a necessary condition for the validity of the FDT, and mixing is a necessary condition for ergodicity. In this work, we compare those results with recent investigations using the Lee recurrence relations method [M.H. Lee, Phys. Rev. B 26 (1982) 2547; M.H. Lee, Phys. Rev. Lett. 87 (2001) 250601; M.H. Lee, J. Phys. A: Math. Gen. 39 (2006) 4651]. Lee shows that ergodicity is violated in the dynamics of the electron gas [M.H. Lee, J. Phys. A: Math. Gen. 39 (2006) 4651]. This reinforces both works and implies that the results of [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] are more general than the framework in which they were obtained. Some applications to slow relaxation phenomena are discussed.

  17. Phantom black holes and critical phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha [Engineering Faculty, Başkent University, Bağlıca Campus, Ankara (Turkey); Marques, Glauber T. [Universidade Federal Rural da Amazônia ICIBE-LASIC, Av. Presidente Tancredo Neves 2501, CEP 66077-901—Belém/PA (Brazil); Rodrigues, Manuel E., E-mail: azreg@baskent.edu.tr, E-mail: gtadaiesky@hotmail.com, E-mail: esialg@gmail.com [Faculdade de Ciências Exatas e Tecnologia, Universidade Federal do Pará, Campus Universitário de Abaetetuba, CEP 68440-000, Abaetetuba, Pará (Brazil)

    2014-07-01

    We consider the two classes cosh and sinh of normal and phantom black holes of Einstein-Maxwell-dilaton theory. The thermodynamics of these holes is characterized by heat capacities that may have both signs depending on the parameters of the theory. Leaving aside the normal Reissner-Nordström black hole, it is shown that only some phantom black holes of both classes exhibit critical phenomena. The two classes share a nonextremality, but special, critical point where the transition is continuous and the heat capacity, at constant charge, changes sign with an infinite discontinuity. This point yields a classification scheme for critical points. It is concluded that the two unstable and stable phases coexist on one side of the criticality state and disappear on the other side, that is, there is no configuration where only one phase exists. The sinh class has an extremality critical point where the entropy diverges. The transition from extremality to nonextremality with the charge held constant is accompanied by a loss of mass and an increase in the temperature. A special case of this transition is when the hole is isolated (microcanonical ensemble), it will evolve by emission of energy, which results in a decrease of its mass, to the final state of minimum mass and vanishing heat capacity. The Ehrenfest scheme of classification is inaccurate in this case but the generalized one due to Hilfer leads to conclude that the transition is of order less than unity. Fluctuations near criticality are also investigated.

  18. Condensation phenomena in a turbine blade passage

    International Nuclear Information System (INIS)

    Skillings, S.A.

    1989-02-01

    The mechanisms associated with the formation and growth of water droplets in the large low-pressure (LP) turbines used for electrical power generation are poorly understood and recent measurements have indicated that an unusually high loss is associated with the initial nucleation of these droplets. In order to gain an insight into the phenomena which arise in the turbine situation, some experiments were performed to investigate the behaviour of condensing steam flows in a blade passage. This study has revealed the fundamental significance of droplet nucleation in modifying the single-phase flow structure and results are presented which show the change in shock wave pattern when inlet superheat and outlet Mach number are varied. The trailing-edge shock wave structure appears considerably more robust towards variation of inlet superheat than purely one-dimensional considerations may suggest and the inadequacies of adopting a one-dimensional theory to analyse multi-dimensional condensing flows are demonstrated. Over a certain range of outlet Mach numbers an oscillating shock wave will establish in the throat region of the blade passage and this has been shown to interact strongly with droplet nucleation, resulting in a considerably increased mean droplet size. The possible implications of these results for turbine performance are also discussed. (author)

  19. Interface-Induced Phenomena in Magnetism.

    Science.gov (United States)

    Hellman, Frances; Hoffmann, Axel; Tserkovnyak, Yaroslav; Beach, Geoffrey S D; Fullerton, Eric E; Leighton, Chris; MacDonald, Allan H; Ralph, Daniel C; Arena, Dario A; Dürr, Hermann A; Fischer, Peter; Grollier, Julie; Heremans, Joseph P; Jungwirth, Tomas; Kimel, Alexey V; Koopmans, Bert; Krivorotov, Ilya N; May, Steven J; Petford-Long, Amanda K; Rondinelli, James M; Samarth, Nitin; Schuller, Ivan K; Slavin, Andrei N; Stiles, Mark D; Tchernyshyov, Oleg; Thiaville, André; Zink, Barry L

    2017-01-01

    This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.

  20. Thermal phenomenae in nuclear fuel rods

    International Nuclear Information System (INIS)

    Baigorria, Carlos.

    1983-12-01

    Thermal phenomenae occurring in a nuclear fuel rod under irradiation are studied. The most important parameters of either steady or transient thermal states are determined. The validity of applying the Fourier's approximation equations to these problems is also studied. A computer program TRANS is developed in order to study the transient cases. This program solves a system of coupled, non-linear partial differential equations, of parabolic type, in cylindrical coordinates with various boundary conditions. The benchmarking of the TRANS program is done by comparing its predictions with the analytical solution of some simplified transient cases. Complex transient cases such as those corresponding to characteristic reactor accidents are studied, in particular for typical pressurized heavy water reactor (PHWR) fuel rods, such as those of Atucha I. The Stefan problem emerging in the case of melting of the fuel element is solved. Qualitative differences between the classical Stefan problem, without inner sources, and that one, which includes sources are discussed. The MSA program, for solving the Stefan problem with inner sources is presented; and furthermore, it serves to predict thermal evolution, when the fuel element melts. Finally a model for fuel phase change under irradiation is developed. The model is based on the dimensional invariants of the percolation theory when applied to the connectivity of liquid spires nucleated around each fission fragment track. Suggestions for future research into the subject are also presented. (autor) [es

  1. Field- and irradiation-induced phenomena in memristive nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Mikhaylov, A.N.; Gryaznov, E.G.; Belov, A.I.; Korolev, D.S.; Sharapov, A.N.; Guseinov, D.V.; Tetelbaum, D.I.; Tikhov, S.V.; Malekhonova, N.V.; Bobrov, A.I.; Pavlov, D.A.; Gerasimova, S.A.; Kazantsev, V.B.; Agudov, N.V.; Dubkov, A.A. [Lobachevsky University, Nizhny Novgorod (Russian Federation); Rosario, C.M.M.; Sobolev, N.A. [Departamento de Fisica and I3N, Universidade de Aveiro (Portugal); Spagnolo, B. [Dipartimento di Fisica e Chimica, Universita di Palermo, Group of Interdisciplinary Theoretical Physics (Italy); CNISM, Unita di Palermo (Italy)

    2016-12-15

    The breakthrough in electronics and information technology is anticipated by the development of emerging memory and logic devices, artificial neural networks and brain-inspired systems on the basis of memristive nanomaterials represented, in a particular case, by a simple 'metal-insulator-metal' (MIM) thin-film structure. The present article is focused on the comparative analysis of MIM devices based on oxides with dominating ionic (ZrO{sub x}, HfO{sub x}) and covalent (SiO{sub x}, GeO{sub x}) bonding of various composition and geometry deposited by magnetron sputtering. The studied memristive devices demonstrate reproducible change in their resistance (resistive switching - RS) originated from the formation and rupture of conductive pathways (filaments) in oxide films due to the electric-field-driven migration of oxygen vacancies and / or mobile oxygen ions. It is shown that, for both ionic and covalent oxides under study, the RS behaviour depends only weakly on the oxide film composition and thickness, device geometry (down to a device size of about 20 x 20 μm{sup 2}). The devices under study are found to be tolerant to ion irradiation that reproduces the effect of extreme fluences of high-energy protons and fast neutrons. This common behaviour of RS is explained by the localized nature of the redox processes in a nanoscale switching oxide volume. Adaptive (synaptic) change of resistive states of memristive devices is demonstrated under the action of single or repeated electrical pulses, as well as in a simple model of coupled (synchronized) neuron-like generators. It is concluded that the noise-induced phenomena cannot be neglected in the consideration of a memristive device as a nonlinear system. The dynamic response of a memristive device to periodic signals of complex waveform can be predicted and tailored from the viewpoint of stochastic resonance concept. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Field- and irradiation-induced phenomena in memristive nanomaterials

    International Nuclear Information System (INIS)

    Mikhaylov, A.N.; Gryaznov, E.G.; Belov, A.I.; Korolev, D.S.; Sharapov, A.N.; Guseinov, D.V.; Tetelbaum, D.I.; Tikhov, S.V.; Malekhonova, N.V.; Bobrov, A.I.; Pavlov, D.A.; Gerasimova, S.A.; Kazantsev, V.B.; Agudov, N.V.; Dubkov, A.A.; Rosario, C.M.M.; Sobolev, N.A.; Spagnolo, B.

    2016-01-01

    The breakthrough in electronics and information technology is anticipated by the development of emerging memory and logic devices, artificial neural networks and brain-inspired systems on the basis of memristive nanomaterials represented, in a particular case, by a simple 'metal-insulator-metal' (MIM) thin-film structure. The present article is focused on the comparative analysis of MIM devices based on oxides with dominating ionic (ZrO_x, HfO_x) and covalent (SiO_x, GeO_x) bonding of various composition and geometry deposited by magnetron sputtering. The studied memristive devices demonstrate reproducible change in their resistance (resistive switching - RS) originated from the formation and rupture of conductive pathways (filaments) in oxide films due to the electric-field-driven migration of oxygen vacancies and / or mobile oxygen ions. It is shown that, for both ionic and covalent oxides under study, the RS behaviour depends only weakly on the oxide film composition and thickness, device geometry (down to a device size of about 20 x 20 μm"2). The devices under study are found to be tolerant to ion irradiation that reproduces the effect of extreme fluences of high-energy protons and fast neutrons. This common behaviour of RS is explained by the localized nature of the redox processes in a nanoscale switching oxide volume. Adaptive (synaptic) change of resistive states of memristive devices is demonstrated under the action of single or repeated electrical pulses, as well as in a simple model of coupled (synchronized) neuron-like generators. It is concluded that the noise-induced phenomena cannot be neglected in the consideration of a memristive device as a nonlinear system. The dynamic response of a memristive device to periodic signals of complex waveform can be predicted and tailored from the viewpoint of stochastic resonance concept. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Polarization phenomena in few-body systems

    International Nuclear Information System (INIS)

    Conzett, H.E.

    1975-12-01

    Recent polarization studies in N--N scattering at and below 50 MeV have provided specific and significant improvements in the phase-shift parameters. High energy investigations with both polarized proton beams and targets have shown unexpectedly large spin effects, and this provides a challenge for theoretical effort to explain these results. Experimental and theoretical work on the three-nucleon problem continues to yield new and interesting results, with the emphasis now shifting to polarization studies in the breakup reaction. On-going work on several-nucleon systems continues to provide polarization data for general analyses, nuclear structure information, or specific resonance effects. Finally, the basic interaction symmetries continue to have unique and important consequences for polarization observables. 17 figures

  4. Delay time and tunneling transient phenomena

    International Nuclear Information System (INIS)

    Garcia-Calderon, Gaston; Villavicencio, Jorge

    2002-01-01

    Analytic solutions to the time-dependent Schroedinger equation for cutoff wave initial conditions are used to investigate the time evolution of the transmitted probability density for tunneling. For a broad range of values of the potential barrier opacity α, we find that the probability density exhibits two evolving structures. One refers to the propagation of a forerunner related to a time domain resonance [Phys. Rev. A 64, 0121907 (2001)], while the other consists of a semiclassical propagating wave front. We find a regime where the forerunners are absent, corresponding to positive time delays, and show that this regime is characterized by opacities α c . The critical opacity α c is derived from the analytical expression for the delay time, which reflects a link between transient effects in tunneling and the delay time

  5. Catastrophes in the interaction of light waves in anisotropic resonator

    International Nuclear Information System (INIS)

    Mkrtchyan, A.R.; Nersisyan, S.R.; Tabiryan, N.V.

    1993-01-01

    An origin of jump-like and hysteresical phenomena is predicted theoretically. Those are caused by the ruling of the state of non-linear anisotropic resonator with an orthogonal polarization of light waves. The resonator creates a turned connection as well as causes a complex tying between the waves. The later conditions a whole number of the interacting waves regimes because of a big number of ruling parameters. 5 refs

  6. Acoustic phenomena observed in lung auscultation

    Science.gov (United States)

    Korenbaum, V. I.; Tagil'Tsev, A. A.; Kulakov, Yu. V.

    2003-05-01

    The results of studying respiratory noise at the chest wall by the method of acoustic intensimetry reveal the presence of frequency components with different signs of the real and imaginary parts of the cross spectrum obtained for the responses of the receivers of vibratory displacement and dynamic force. An acoustic model is proposed to explain this difference on the basis of the hypothesis that the contributions of both air-borne and structure-borne sound are significant in the transmission of respiratory noise to the chest wall. It is shown that, when considered as an acoustic channel for the basic respiratory noise, the respiratory system of an adult subject has two resonances: in the frequency bands within 110 150 and 215 350 Hz. For adults in normal condition, the air-borne component of the basic respiratory noise predominates in the region 100 300 Hz in the lower parts of lungs. At forced respiration of healthy adults, the sounds of vesicular respiration are generated by the turbulent air flow in the 11th-through 13th-generation bronchi, and the transmission of these sounds to the chest wall in normal condition is mainly through air and is determined by the resonance of the vibratory system formed by the elasticity of air in the respiratory ducts of lungs and by the surface mass density of the chest wall. It is demonstrated that the distance from the chest wall to the sources of structure-borne additional respiratory noise, namely, wheezing with frequencies above 300 Hz, can be estimated numerically from the ratio between the real and imaginary parts of the cross spectrum on the assumption that the source is of the quadrupole type.

  7. Natural phenomena hazards, Hanford Site, south central Washington

    International Nuclear Information System (INIS)

    Tallman, A.M.

    1996-01-01

    This document presents the natural phenomena hazard (NPH) loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, at the Hanford Site in south-central Washington State. The purpose of this document is twofold: (1) summarize the NPH that are important to the design and evaluation of structures, systems, and components at the Hanford Site; (2) develop the appropriate natural phenomena loads for use in the implementation of DOE Order 5480.28. The supporting standards, DOE-STD-1020-94, Natural Phenomena Hazards Design and Evaluation Criteria for Department of Energy Facilities (DOE 1994a); DOE-STD-1022-94, Natural Phenomena Hazards Site Characteristics Criteria (DOE 1994b); and DOE-STD-1023-95, Natural Phenomena Hazards Assessment Criteria (DOE 1995) are the basis for developing the NPH loads

  8. Applied neutron resonance theory

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1980-01-01

    Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (author)

  9. Applied neutron resonance theory

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1978-07-01

    Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (orig.) [de

  10. Classification of debris flow phenomena in the Faroe Islands

    DEFF Research Database (Denmark)

    Dahl, Mads-Peter Jakob; E. Mortensen, Lis; Jensen, Niels H.

    2012-01-01

    Landslides and debris flow phenomena in particular constitute a threat to human activities in the Faroe Islands. As a contribution to ongoing landslide risk management research, this paper proposes a classification scheme for debris flow phenomena in the Faroe Islands. The scheme, produced through...... a multidisciplinary study involving geomorphological fieldwork and qualitative collection of indigenous landslide knowledge, presents physical characteristics to classify debris flow phenomena into groups named with Faroese terms. The following landslide definitions are proposed. Brekku-skriðulop (English translation...... with international landslide classification systems, significantly increases the knowledge of debris flow phenomena and promotes a consistent terminology of these within the Faroe Islands....

  11. Statistical trend analysis methods for temporal phenomena

    International Nuclear Information System (INIS)

    Lehtinen, E.; Pulkkinen, U.; Poern, K.

    1997-04-01

    We consider point events occurring in a random way in time. In many applications the pattern of occurrence is of intrinsic interest as indicating a trend or some other systematic feature in the rate of occurrence. The purpose of this report is to survey briefly different statistical trend analysis methods and illustrate their applicability to temporal phenomena in particular. The trend testing of point events is usually seen as the testing of the hypotheses concerning the intensity of the occurrence of events. When the intensity function is parametrized, the testing of trend is a typical parametric testing problem. In industrial applications the operational experience generally does not suggest any specified model and method in advance. Therefore, and particularly, if the Poisson process assumption is very questionable, it is desirable to apply tests that are valid for a wide variety of possible processes. The alternative approach for trend testing is to use some non-parametric procedure. In this report we have presented four non-parametric tests: The Cox-Stuart test, the Wilcoxon signed ranks test, the Mann test, and the exponential ordered scores test. In addition to the classical parametric and non-parametric approaches we have also considered the Bayesian trend analysis. First we discuss a Bayesian model, which is based on a power law intensity model. The Bayesian statistical inferences are based on the analysis of the posterior distribution of the trend parameters, and the probability of trend is immediately seen from these distributions. We applied some of the methods discussed in an example case. It should be noted, that this report is a feasibility study rather than a scientific evaluation of statistical methods, and the examples can only be seen as demonstrations of the methods

  12. Statistical trend analysis methods for temporal phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, E.; Pulkkinen, U. [VTT Automation, (Finland); Poern, K. [Poern Consulting, Nykoeping (Sweden)

    1997-04-01

    We consider point events occurring in a random way in time. In many applications the pattern of occurrence is of intrinsic interest as indicating a trend or some other systematic feature in the rate of occurrence. The purpose of this report is to survey briefly different statistical trend analysis methods and illustrate their applicability to temporal phenomena in particular. The trend testing of point events is usually seen as the testing of the hypotheses concerning the intensity of the occurrence of events. When the intensity function is parametrized, the testing of trend is a typical parametric testing problem. In industrial applications the operational experience generally does not suggest any specified model and method in advance. Therefore, and particularly, if the Poisson process assumption is very questionable, it is desirable to apply tests that are valid for a wide variety of possible processes. The alternative approach for trend testing is to use some non-parametric procedure. In this report we have presented four non-parametric tests: The Cox-Stuart test, the Wilcoxon signed ranks test, the Mann test, and the exponential ordered scores test. In addition to the classical parametric and non-parametric approaches we have also considered the Bayesian trend analysis. First we discuss a Bayesian model, which is based on a power law intensity model. The Bayesian statistical inferences are based on the analysis of the posterior distribution of the trend parameters, and the probability of trend is immediately seen from these distributions. We applied some of the methods discussed in an example case. It should be noted, that this report is a feasibility study rather than a scientific evaluation of statistical methods, and the examples can only be seen as demonstrations of the methods. 14 refs, 10 figs.

  13. On resonance phenomena in a stellarator with longitudinal current in a plasma

    International Nuclear Information System (INIS)

    Aleksin, V.F.; Pyatov, V.N.; Sebko, V.P.; Tyupa, V.I.

    1976-01-01

    A magnetic configuration structure of a stellarator with a current plasma has been considered in the presence of small disturbances. Structures of magnetic fields of a real stellarator configuration with a longitudinal current in a plasma have been obtained by means of averaged coordinates with the subsequent transition to real coordinates. The development of a socket structure and destruction of an integral configuration with an increase of the disturbance amplitude are demonstrated, its range of variation is within the limits of 0.1+-0.01%. Deformations of sockets in different cross sections of the magnetic system along the toroidal axis have been investigated. The results of calculations agree with experimental data obtained at stellarators with a current plasma

  14. Phenomena of nonlinear oscillation and special resonance of a dielectric elastomer minimum energy structure rotary joint

    Science.gov (United States)

    Zhao, Jianwen; Niu, Junyang; McCoul, David; Ren, Zhi; Pei, Qibing

    2015-03-01

    The dielectric elastomer minimum energy structure can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer, so it is a suitable candidate to make a rotary joint for a soft robot. Driven with an alternating electric field, the joint deformation vibrational frequency follows the input voltage frequency. However, the authors find that if the rotational inertia increases such that the inertial torque makes the frame deform over a negative angle, then the joint motion will become complicated and the vibrational mode will alter with the change of voltage frequency. The vibration with the largest amplitude does not occur while the voltage frequency is equal to natural response frequency of the joint. Rather, the vibrational amplitude will be quite large over a range of other frequencies at which the vibrational frequency is half of the voltage frequency. This phenomenon was analyzed by a comparison of the timing sequences between voltage and joint vibration. This vibrational mode with the largest amplitude can be applied to the generation lift in a flapping wing actuated by dielectric elastomers.

  15. Narrow dibaryon resonances

    International Nuclear Information System (INIS)

    Kajdalov, A.B.

    1986-01-01

    Experimental data on np interactions indicating to existence of narrow resonances in pp-system are discussed. Possible theoretical interpretations of these resonances are given. Experimental characteristics of the dibaryon resonances with isospin I=2 are considered

  16. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

  17. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  18. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  19. Simulation with Python on transverse modes of the symmetric confocal resonator

    Science.gov (United States)

    Wang, Qing Hua; Qi, Jing; Ji, Yun Jing; Song, Yang; Li, Zhenhua

    2017-08-01

    Python is a popular open-source programming language that can be used to simulate various optical phenomena. We have developed a suite of programs to help teach the course of laser principle. The complicated transverse modes of the symmetric confocal resonator can be visualized in personal computers, which is significant to help the students understand the pattern distribution of laser resonator.

  20. Harmonic Resonances in Metal Rods--Easy Experimentation with a Smartphone and Tablet PC

    Science.gov (United States)

    Hirth, Michael; Gröber, Sebastian; Kuhn, Jochen; Müller, Andreas

    2016-01-01

    A variety of experiments with smartphones and tablet PCs allow a precise analysis of acoustic phenomena. For example, we recently described an experiment in which a noise signal simultaneously triggered harmonic acoustic resonances in the air column of a tube open at both ends and a tube closed at one end. The measured resonant frequencies were…

  1. Saving the Phenomena in Medieval Astronomy

    Science.gov (United States)

    Seeskin, K.

    2011-06-01

    Aristotle's theory of motion is based on two principles: (1) all motion to either from the midpoint of the Earth, toward it, or around it, and (2) circular motion must proceed around an immovable point. On this view, the heavenly bodies are individual points of light carried around by a series of concentric spheres rotating at a constant pace around the midpoint of the Earth. But even in Aristotle's day, it was known that this theory had a great deal of difficulty accounting for planetary motion. Ptolemy's alternative was to introduce epicycles and eccentric orbits, thus denying Aristotle's view of natural motion. There was no doubt that Ptolemy's predictions were far better than Aristotle's. But for the medievals, Aristotle's theory made better intuitive sense. Moreover, Ptolemy's theory raised the question of how one sphere could pass through another. What to do? The solution of Moses Maimonides (1138-1204) was to say that it is not the job of the astronomer to tell us how things actually are but merely to propose a series of hypotheses that allow us to explain the relevant data. This view had obvious theological implications. If astronomy could explain planetary motion in an acceptable way, there was reason to believe that the order or structure of the heavens is what it is by necessity. This suggests that God did not exercise any degree of choice in making it that way. But if astronomy cannot explain planetary motion, the most reasonable explanation is that we are dealing with contingent phenomena rather than necessary ones. If there is contingency, there is reason to think God did exercise a degree of choice in making the heavens the way they are. A God who exercises choice is much closer to the God of Scripture. Although Galileo changed all of this, and paved the way for a vastly different view of astronomy, the answer to one set of questions raises a whole different set. In short, the heavenly motion still poses ultimate questions about God, existence, and

  2. Resonances, resonance functions and spectral deformations

    International Nuclear Information System (INIS)

    Balslev, E.

    1984-01-01

    The present paper is aimed at an analysis of resonances and resonance states from a mathematical point of view. Resonances are characterized as singular points of the analytically continued Lippman-Schwinger equation, as complex eigenvalues of the Hamiltonian with a purely outgoing, exponentially growing eigenfunction, and as poles of the S-matrix. (orig./HSI)

  3. Nonlinear resonance in Duffing oscillator with fixed and integrative ...

    Indian Academy of Sciences (India)

    We study the nonlinear resonance, one of the fundamental phenomena in nonlinear oscillators, in a damped and periodically-driven Duffing oscillator with two types of time-delayed feedbacks, namely, fixed and integrative. Particularly, we analyse the effect of the time-delay parameter and the strength of the ...

  4. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Nobel Prize 2000 in Physiology or Medicine - Trackers of the Slow Synaptic Phenomena in the Brain. S K Sikdar. General Article Volume 6 Issue 7 July 2001 pp 42-51 ...

  5. Nonlinear resonance in Duffing oscillator with fixed and integrative ...

    Indian Academy of Sciences (India)

    2012-03-02

    Mar 2, 2012 ... Abstract. We study the nonlinear resonance, one of the fundamental phenomena in nonlinear oscillators, in a damped and periodically-driven Duffing oscillator with two types of time-delayed feedbacks, namely, fixed and integrative. Particularly, we analyse the effect of the time-delay parameter α and the ...

  6. In search of high density collective phenomena in nuclear collision

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1979-06-01

    The progress made toward uncovering signatures of collective phenomena is reviewed. Elements of the basic reaction mechanism leading to a complex background are first discussed. Possible hints of collective phenomena in proton and pion single and double inclusive spectra as well as π - multiplicity data are then described. 6 figures, 2 tables

  7. Collective phenomena in photonic, plasmonic and hybrid structures.

    Science.gov (United States)

    Boriskina, Svetlana V; Povinelli, Michelle; Astratov, Vasily N; Zayats, Anatoly V; Podolskiy, Viktor A

    2011-10-24

    Preface to a focus issue of invited articles that review recent progress in studying the fundamental physics of collective phenomena associated with coupling of confined photonic, plasmonic, electronic and phononic states and in exploiting these phenomena to engineer novel devices for light generation, optical sensing, and information processing. © 2011 Optical Society of America

  8. Ether and interpretation of some physical phenomena and concepts

    International Nuclear Information System (INIS)

    Rzayev, S.G.

    2008-01-01

    On the basis of the concept of existence of an ether representation about time, space, matters and physical field are profound and also the essence of such phenomena, as corpuscular - wave dualism, change of time, scale and mass at movement body's is opened. The opportunity of transition from probability-statistical interpretation of the quantum phenomena to Laplace's determinism is shown

  9. Current status of studies on temperature fluctuation phenomena in LMFRs

    International Nuclear Information System (INIS)

    Ohshima, H.; Muramatsu, T.; Kobayashi, J.; Yamaguchi, A.

    1994-01-01

    This paper describes the current status of studies being performed in PNC on temperature fluctuation phenomena occurring in fast reactors. The studies concentrate on four problems: thermal stratification, thermal striping, core-plenum interaction and free surface sloshing. Both experimental and analytical approaches to reveal these phenomena and to establish design and safety evaluation methods are presented together with future works. (author)

  10. Positive muscle phenomena-diagnosis, pathogenesis and associated disorders

    NARCIS (Netherlands)

    Kortman, Hans G.; Veldink, Jan H.; Drost, Gea

    Positive muscle phenomena arise owing to various forms of spontaneous muscle hyperactivity originating in motor neurons or in the muscle itself. Although they are common in a wide range of neurological and non-neurological diseases, clinical and scientific data on these phenomena are limited, and

  11. Resonator memories and optical novelty filters

    Science.gov (United States)

    Anderson, Dana Z.; Erle, Marie C.

    Optical resonators having holographic elements are potential candidates for storing information that can be accessed through content addressable or associative recall. Closely related to the resonator memory is the optical novelty filter, which can detect the differences between a test object and a set of reference objects. We discuss implementations of these devices using continuous optical media such as photorefractive materials. The discussion is framed in the context of neural network models. There are both formal and qualitative similarities between the resonator memory and optical novelty filter and network models. Mode competition arises in the theory of the resonator memory, much as it does in some network models. We show that the role of the phenomena of "daydreaming" in the real-time programmable optical resonator is very much akin to the role of "unlearning" in neural network memories. The theory of programming the real-time memory for a single mode is given in detail. This leads to a discussion of the optical novelty filter. Experimental results for the resonator memory, the real-time programmable memory, and the optical tracking novelty filter are reviewed. We also point to several issues that need to be addressed in order to implement more formal models of neural networks.

  12. Parasitic phenomena in the dynamics of industrial devices

    CERN Document Server

    Borboni, Alberto

    2011-01-01

    In the real world the dynamic behavior of a real machine presents either unforeseen or limiting phenomena: both are undesired, and can be therefore be classified as parasitic phenomena - unwanted, unforeseen, or limiting behaviors. Parasitic Phenomena in the Dynamics of Industrial Devices describes the potential causes and effects of these behaviors and provides indications that could minimize their influence on the mechanical system in question. The authors introduce the phenomena and explore them through real cases, avoiding academic introductions, but inserting the entire academic and experimental knowledge that is useful to understand and solve real-world problems. They then examine these parasitic phenomena in the machine dynamics, using two cases that cover the classical cultural division between cam devices and mechanisms. They also present concrete cases with an amount of experimental data higher than the proposed ones and with a modern approach that can be applied to various mechanical devices, acqui...

  13. Phenomena based Methodology for Process Synthesis incorporating Process Intensification

    DEFF Research Database (Denmark)

    Lutze, Philip; Babi, Deenesh Kavi; Woodley, John

    2013-01-01

    at processes at the lowest level of aggregation which is the phenomena level. In this paper, a phenomena based synthesis/design methodology incorporating process intensification is presented. Using this methodology, a systematic identification of necessary and desirable (integrated) phenomena as well......Process intensification (PI) has the potential to improve existing as well as conceptual processes, in order to achieve a more sustainable production. PI can be achieved at different levels. That is, the unit operations, functional and/or phenomena level. The highest impact is expected by looking...... as generation and screening of phenomena based flowsheet options are presented using a decomposition based solution approach. The developed methodology as well as necessary tools and supporting methods are highlighted through a case study involving the production of isopropyl-acetate....

  14. Stochastic resonance

    International Nuclear Information System (INIS)

    Wellens, Thomas; Shatokhin, Vyacheslav; Buchleitner, Andreas

    2004-01-01

    We are taught by conventional wisdom that the transmission and detection of signals is hindered by noise. However, during the last two decades, the paradigm of stochastic resonance (SR) proved this assertion wrong: indeed, addition of the appropriate amount of noise can boost a signal and hence facilitate its detection in a noisy environment. Due to its simplicity and robustness, SR has been implemented by mother nature on almost every scale, thus attracting interdisciplinary interest from physicists, geologists, engineers, biologists and medical doctors, who nowadays use it as an instrument for their specific purposes. At the present time, there exist a lot of diversified models of SR. Taking into account the progress achieved in both theoretical understanding and practical application of this phenomenon, we put the focus of the present review not on discussing in depth technical details of different models and approaches but rather on presenting a general and clear physical picture of SR on a pedagogical level. Particular emphasis will be given to the implementation of SR in generic quantum systems-an issue that has received limited attention in earlier review papers on the topic. The major part of our presentation relies on the two-state model of SR (or on simple variants thereof), which is general enough to exhibit the main features of SR and, in fact, covers many (if not most) of the examples of SR published so far. In order to highlight the diversity of the two-state model, we shall discuss several examples from such different fields as condensed matter, nonlinear and quantum optics and biophysics. Finally, we also discuss some situations that go beyond the generic SR scenario but are still characterized by a constructive role of noise

  15. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Directory of Open Access Journals (Sweden)

    Seppo E. Iso-Ahola

    2017-06-01

    Full Text Available Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1 scientific method itself is seriously limited (i.e., it can never prove a negative; (2 non-existence of phenomena would require a complete absence of both logical (theoretical and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3 statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4 psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance, not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested.

  16. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Science.gov (United States)

    Iso-Ahola, Seppo E.

    2017-01-01

    Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1) scientific method itself is seriously limited (i.e., it can never prove a negative); (2) non-existence of phenomena would require a complete absence of both logical (theoretical) and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3) statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4) psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size) are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance), not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested. PMID:28626435

  17. State estimation of spatio-temporal phenomena

    Science.gov (United States)

    Yu, Dan

    This dissertation addresses the state estimation problem of spatio-temporal phenomena which can be modeled by partial differential equations (PDEs), such as pollutant dispersion in the atmosphere. After discretizing the PDE, the dynamical system has a large number of degrees of freedom (DOF). State estimation using Kalman Filter (KF) is computationally intractable, and hence, a reduced order model (ROM) needs to be constructed first. Moreover, the nonlinear terms, external disturbances or unknown boundary conditions can be modeled as unknown inputs, which leads to an unknown input filtering problem. Furthermore, the performance of KF could be improved by placing sensors at feasible locations. Therefore, the sensor scheduling problem to place multiple mobile sensors is of interest. The first part of the dissertation focuses on model reduction for large scale systems with a large number of inputs/outputs. A commonly used model reduction algorithm, the balanced proper orthogonal decomposition (BPOD) algorithm, is not computationally tractable for large systems with a large number of inputs/outputs. Inspired by the BPOD and randomized algorithms, we propose a randomized proper orthogonal decomposition (RPOD) algorithm and a computationally optimal RPOD (RPOD*) algorithm, which construct an ROM to capture the input-output behaviour of the full order model, while reducing the computational cost of BPOD by orders of magnitude. It is demonstrated that the proposed RPOD* algorithm could construct the ROM in real-time, and the performance of the proposed algorithms on different advection-diffusion equations. Next, we consider the state estimation problem of linear discrete-time systems with unknown inputs which can be treated as a wide-sense stationary process with rational power spectral density, while no other prior information needs to be known. We propose an autoregressive (AR) model based unknown input realization technique which allows us to recover the input

  18. Certain relativistic phenomena in crystal optics

    Science.gov (United States)

    Chee-Seng, Lim

    1980-01-01

    Relativistic unsteady phenomena are established for a crystalline medium with unaligned sets of permittivity and permeability principal axes, but incorporating a compounded uniaxiality about some nonprincipal direction. All effects originate from a suddenly activated, arbitrarily oriented, maintained line current conducted with a finite velocity v. Integral representations studied in another paper (Chee-Seng) are applied. The original coordinate system is subjected to a series of rotational and translational, scaled and unscaled transformations. No specific coordinate frame is strictly adhered to. Instead, it is often expedient and advantageous to exploit several reference frames simultaneously in the course of the analysis and interpretations. The electric field is directly related to a net scalar field Δ involving another scalar Ψ and its complement Ψ¯ which can be deduced from Ψ; Ψ and Ψ¯ are associated with two expanding, inclined ellipsoidal wavefronts ξ and ξ¯; these are cocentered at the current origin and touch each other twice along the uniaxis. Elsewhere, ξ leads ξ¯. For a source current faster than ξ:vt ∈ extξ, Ψ≢0 within a finite but growing ''ice-cream cone'' domain, its nontrivial composition being χ-1/2 inside ξ and 2χ-1/2 inside part of a tangent cone from the advancing current edge vt to, and terminating at, ξ; the function χ vanishes along such a tangent cone. Alternatively, for a source current slower than ξ:vt∈ intξ, if vt is avoided, χ≳0 everywhere, while Ψ=χ-1/2 inside ξ but vanishes identically outside ξ. However, the crucial scalar field Δ depends on three separate current-velocity regimes. Over a slow regime: vt∈ intξ¯, Δ is nontrivial inside ξ wherein it is discontinuous across ξ¯. Over an intermediate regime: vt ∈ intξ extξ¯, Δ takes four distinct forms on 12 adjacent domains bounded by ξ, ξ¯ and a double-conical tangent surface linking vt to ξ¯. But for a fast regime: vt∈ ext

  19. Brain structural correlates of sensory phenomena in patients with obsessive–compulsive disorder

    Science.gov (United States)

    Subirà, Marta; Sato, João R.; Alonso, Pino; do Rosário, Maria C.; Segalàs, Cinto; Batistuzzo, Marcelo C.; Real, Eva; Lopes, Antonio C.; Cerrillo, Ester; Diniz, Juliana B.; Pujol, Jesús; Assis, Rachel O.; Menchón, José M.; Shavitt, Roseli G.; Busatto, Geraldo F.; Cardoner, Narcís; Miguel, Euripedes C.; Hoexter, Marcelo Q.; Soriano-Mas, Carles

    2015-01-01

    Background Sensory phenomena (SP) are uncomfortable feelings, including bodily sensations, sense of inner tension, “just-right” perceptions, feelings of incompleteness, or “urge-only” phenomena, which have been described to precede, trigger or accompany repetitive behaviours in individuals with obsessive–compulsive disorder (OCD). Sensory phenomena are also observed in individuals with tic disorders, and previous research suggests that sensorimotor cortex abnormalities underpin the presence of SP in such patients. However, to our knowledge, no studies have assessed the neural correlates of SP in patients with OCD. Methods We assessed the presence of SP using the University of São Paulo Sensory Phenomena Scale in patients with OCD and healthy controls from specialized units in São Paulo, Brazil, and Barcelona, Spain. All participants underwent a structural magnetic resonance examination, and brain images were examined using DARTEL voxel-based morphometry. We evaluated grey matter volume differences between patients with and without SP and healthy controls within the sensorimotor and premotor cortices. Results We included 106 patients with OCD and 87 controls in our study. Patients with SP (67% of the sample) showed grey matter volume increases in the left sensorimotor cortex in comparison to patients without SP and bilateral sensorimotor cortex grey matter volume increases in comparison to controls. No differences were observed between patients without SP and controls. Limitations Most patients were medicated. Participant recruitment and image acquisition were performed in 2 different centres. Conclusion We have identified a structural correlate of SP in patients with OCD involving grey matter volume increases within the sensorimotor cortex; this finding is in agreement with those of tic disorder studies showing that abnormal activity and volume increases within this region are associated with the urges preceding tic onset. PMID:25652753

  20. Nonequilibrium emergent phenomena in organic molecular solids

    Energy Technology Data Exchange (ETDEWEB)

    Mitrano, Matteo

    2015-07-15

    vibrational excitations, we then show the possibility of driving a superconducting phase transition by transiently perturbing those degrees of freedom that mediate the pairing interaction. We select the molecular solid K{sub 3}C{sub 60}, a well characterized superconductor at relatively high temperatures (T{sub c}=19.8 K) in which high-energy intramolecular vibrations are considered as key for the Cooper pairing. When driven with strong midinfrared fields resonantly tuned to infrared active intramolecular vibrations, we induce a short-lived transient state with striking superconducting-like optical properties above the equilibrium transition temperature and up to 100 K, five times the equilibrium T{sub c}. We explain the appearance of this superconducting-like behavior in terms of light-induced structural distortions capable to induce changes in the onsite Coulomb correlation and in the electron-phonon coupling.

  1. Mode Coupling and Nonlinear Resonances of MEMS Arch Resonators for Bandpass Filters

    KAUST Repository

    Hajjaj, Amal Z.

    2017-01-30

    We experimentally demonstrate an exploitation of the nonlinear softening, hardening, and veering phenomena (near crossing), where the frequencies of two vibration modes get close to each other, to realize a bandpass filter of sharp roll off from the passband to the stopband. The concept is demonstrated based on an electrothermally tuned and electrostatically driven MEMS arch resonator operated in air. The in-plane resonator is fabricated from a silicon-on-insulator wafer with a deliberate curvature to form an arch shape. A DC current is applied through the resonator to induce heat and modulate its stiffness, and hence its resonance frequencies. We show that the first resonance frequency increases up to twice of the initial value while the third resonance frequency decreases until getting very close to the first resonance frequency. This leads to the phenomenon of veering, where both modes get coupled and exchange energy. We demonstrate that by driving both modes nonlinearly and electrostatically near the veering regime, such that the first and third modes exhibit softening and hardening behavior, respectively, sharp roll off from the passband to the stopband is achievable. We show a flat, wide, and tunable bandwidth and center frequency by controlling the electrothermal actuation voltage.

  2. Noise in nonlinear nanoelectromechanical resonators

    Science.gov (United States)

    Guerra Vidal, Diego N.

    Nano-Electro-Mechanical Systems (NEMS), due to their nanometer scale size, possess a number of desirable attributes: high sensitivity to applied forces, fast response times, high resonance frequencies and low power consumption. However, ultra small size and low power handling result in unwanted consequences: smaller signal size and higher dissipation, making the NEMS devices more susceptible to external and intrinsic noise. The simplest version of a NEMS, a suspended nanomechanical structure with two distinct excitation states, can be used as an archetypal two state system to study a plethora of fundamental phenomena such as Duffing nonlinearity, stochastic resonance, and macroscopic quantum tunneling at low temperatures. From a technical perspective, there are numerous applications such nanomechanical memory elements, microwave switches and nanomechanical computation. The control and manipulation of the mechanical response of these two state systems can be realized by exploiting a (seemingly) counterintuitive physical phenomenon, Stochastic Resonance: in a noisy nonlinear mechanical system, the presence of noise can enhance the system response to an external stimulus. This Thesis is mainly dedicated to study possible applications of Stochastic Resonance in two-state nanomechanical systems. First, on chip signal amplification by 1/falpha is observed. The effectiveness of the noise assisted amplification is observed to decrease with increasing a. Experimental evidence shows an increase in asymmetry between the two states with increasing noise color. Considering the prevalence of 1/f alpha noise in the materials in integrated circuits, the signal enhancement demonstrated here, suggests beneficial use of the otherwise detrimental noise. Finally, a nanomechanical device, operating as a reprogrammable logic gate, and performing fundamental logic functions such as AND/OR and NAND/NOR is presented. The logic function can be programmed (from AND to OR) dynamically, by

  3. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    The thesis contains the results of my recent projects in astrophysical research. All projects aim at pushing the limits of our knowledge about the interaction between a galaxy, the fundamental building block of today's universe, and a supermassive black hole (SMBH) at its center. Over the past years a lot of observational evidence has been gathered for the current understanding, that at least a major part of the galaxies with a stellar bulge contain central SMBHs. The typical extragalactic approach consists of searching for the spectroscopic pattern of Keplerian rotation, produced by stars and gas, when orbiting a central dark mass (Kormendy & Richstone 1995). It suggests that a significant fraction of large galaxies host in their very nucleus a SMBH of millions to billions of solar masses (Kormendy & Gebhardt 2001). In the closest case, the center of our Milky Way, the most central stars, which can be imaged, were shown to move on orbits with circulation times of a few decades only, evidencing a mass and compactness of the dark counter part of the Keplerian motion, which can only be explained by a SMBH (Eckart & Genzel 1996; Ghez et al. 2000; Schödel et al. 2002). Having acknowledged the widespread existence of SMBHs the obvious next step is investigating the interaction with their environment. Although the basic property of a SMBH, which is concentrating a huge amount of mass in a ludicrously small volume defined by the Schwarzschild radius, only creates a deep gravitational trough, its existence evokes much more phenomena than simply attracting the surrounding matter. It can trigger or exacerbate star formation via tidal forces (Morris 1993). It shapes the distribution of its surrounding matter to accretion discs, which themselves release gravitational potential energy as radiation, possibly due to magnetic friction (Blandford 1995). The radiation efficiency of such active galactic nuclei (AGN) can become roughly 100 times more efficient than atomic nuclear

  4. Temperature dependence of microwave absorption phenomena in single and biphase soft magnetic microwires

    Energy Technology Data Exchange (ETDEWEB)

    El Kammouni, Rhimou, E-mail: elkammounirhimou@gmail.com [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Vázquez, Manuel [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Lezama, Luis [Depto. Química Inorgánica, Universidad País Vasco, UPV/EHU, Bilbao (Spain); Kurlyandskaya, Galina [Depto. Electricidad y Electrónica, Universidad País Vasco, UPV/EHU, Bilbao (Spain); Dept. Magnetism and Magnetic Nanomaterials, Ural Federal University, Ekaterinburg (Russian Federation); Kraus, Ludek [Institute of Physics, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

    2014-11-15

    The microwave absorption phenomena of single and biphase magnetic microwires with soft magnetic behavior have been investigated as a function of DC applied magnetic field using two alternative techniques: (i) absorption measurements in the temperature range of 4–300 K using a spectrometer operating at X-band frequency, at 9.5 GHz, and (ii) room-temperature, RT, ferromagnetic resonance measurements in a network analyzer in the frequency range up to 20 GHz. Complementary low-frequency magnetic characterization was performed in a Vibrating Sample Magnetometer. Studies have been performed for 8 μm diameter small-magnetostriction amorphous CoFeSiB single-phase microwire, coated by micrometric Pyrex layer, and after electroplating an external shell, 2 µm or 4 µm thick, of FeNi alloys. For single phase CoFeSiB microwire, a single absorption is observed, whose DC field dependence of resonance frequency at RT fits to a Kittel-law behavior for in-plane magnetized thin film. The temperature dependence behavior shows a monotonic increase in the resonance field, H{sub r}, with temperature. A parallel reduction of the circular anisotropy field, H{sub K}, is deduced from the temperature dependence of hysteresis loops. For biphase, CoFeSiB/FeNi, microwires, the absorption phenomena at RT also follow the Kittel condition. The observed opposite evolution with temperature of resonance field, H{sub r}, in 2 and 4 µm thick FeNi samples is interpreted considering the opposite sign of magnetostriction of the respective FeNi layers. The stress-induced magnetic anisotropy field, H{sub K}, in the FeNi shell is deduced to change sign at around 130 K. - Highlights: • A single absorption phenomenon is observed for single phase CoFeSiB. • The T dependence of the microwave behavior shows a monotonic increase of H{sub r} with T. • The absorption at RT follows the Kittel condition for biphase CoFe/FeNi microwires. • The T dependence of resonant field of CoFe/FeNi is interpreted to be

  5. Realistic generation of natural phenomena based on video synthesis

    Science.gov (United States)

    Wang, Changbo; Quan, Hongyan; Li, Chenhui; Xiao, Zhao; Chen, Xiao; Li, Peng; Shen, Liuwei

    2009-10-01

    Research on the generation of natural phenomena has many applications in special effects of movie, battlefield simulation and virtual reality, etc. Based on video synthesis technique, a new approach is proposed for the synthesis of natural phenomena, including flowing water and fire flame. From the fire and flow video, the seamless video of arbitrary length is generated. Then, the interaction between wind and fire flame is achieved through the skeleton of flame. Later, the flow is also synthesized by extending the video textures using an edge resample method. Finally, we can integrate the synthesized natural phenomena into a virtual scene.

  6. Electron impact phenomena and the properties of gaseous ions

    CERN Document Server

    Field, F H; Massey, H S W; Brueckner, Keith A

    1970-01-01

    Electron Impact Phenomena and the Properties of Gaseous Ions, Revised Edition deals with data pertaining to electron impact and to molecular gaseous ionic phenomena. This book discusses electron impact phenomena in gases at low pressure that involve low-energy electrons, which result in ion formation. The text also describes the use of mass spectrometers in electron impact studies and the degree of accuracy obtained when measuring electron impact energies. This book also reviews relatively low speed electrons and the transitions that result in the ionization of the atomic system. This text the

  7. Transient vibration phenomena in deep mine hoisting cables. Part 1: Mathematical model

    Science.gov (United States)

    Kaczmarczyk, S.; Ostachowicz, W.

    2003-04-01

    The classical moving co-ordinate frame approach and Hamilton's principle are employed to derive a distributed-parameter mathematical model to investigate the dynamic behaviour of deep mine hoisting cables. This model describes the coupled lateral-longitudinal dynamic response of the cables in terms of non-linear partial differential equations that accommodate the non-stationary nature of the system. Subsequently, the Rayleigh-Ritz procedure is applied to formulate a discrete mathematical model. Consequently, a system of non-linear non-stationary coupled second order ordinary differential equations arises to govern the temporal behaviour of the cable system. This discrete model with quadratic and cubic non-linear terms describes the modal interactions between lateral oscillations of the catenary cable and longitudinal oscillations of the vertical rope. It is shown that the response of the catenary-vertical rope system may feature a number of resonance phenomena, including external, parametric and autoparametric resonances. The parameters of a typical deep mine winder are used to identify the depth locations of the resonance regions during the ascending cycles with various winding velocities.

  8. Plasma phenomena around comets: interaction with the solar wind

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Shapiro, V.D.; Shevchenko, V.I.; Szegoe, K.

    1987-08-01

    The most important plasma physical experimental data measured during the cometary missions are summarized. These data do not include tail phenomena. Theoretical considerations are also presented concerning the upstream and bow shock regions. (author) 47 refs.; 15 figs

  9. Nonlinear structural mechanics theory, dynamical phenomena and modeling

    CERN Document Server

    Lacarbonara, Walter

    2013-01-01

    Nonlinear Structural Mechanics: Theory, Dynamical Phenomena and Modeling offers a concise, coherent presentation of the theoretical framework of nonlinear structural mechanics, computational methods, applications, parametric investigations of nonlinear phenomena and their mechanical interpretation towards design. The theoretical and computational tools that enable the formulation, solution, and interpretation of nonlinear structures are presented in a systematic fashion so as to gradually attain an increasing level of complexity of structural behaviors, under the prevailing assumptions on the geometry of deformation, the constitutive aspects and the loading scenarios. Readers will find a treatment of the foundations of nonlinear structural mechanics towards advanced reduced models, unified with modern computational tools in the framework of the prominent nonlinear structural dynamic phenomena while tackling both the mathematical and applied sciences. Nonlinear Structural Mechanics: Theory, Dynamical Phenomena...

  10. Inverse Analysis of Cavitation Impact Phenomena on Structures

    National Research Council Canada - National Science Library

    Lambrakos, S. G; Tran, N. E

    2007-01-01

    A general methodology is presented for in situ detection of cavitation impact phenomena on structures based on inverse analysis of luminescent emissions resulting from the collapsing of bubbles onto surfaces...

  11. Phase Plane Analysis Method of Nonlinear Traffic Phenomena

    Directory of Open Access Journals (Sweden)

    Wenhuan Ai

    2015-01-01

    Full Text Available A new phase plane analysis method for analyzing the complex nonlinear traffic phenomena is presented in this paper. This method makes use of variable substitution to transform a traditional traffic flow model into a new model which is suitable for the analysis in phase plane. According to the new model, various traffic phenomena, such as the well-known shock waves, rarefaction waves, and stop-and-go waves, are analyzed in the phase plane. From the phase plane diagrams, we can see the relationship between traffic jams and system instability. So the problem of traffic flow could be converted into that of system stability. The results show that the traffic phenomena described by the new method is consistent with that described by traditional methods. Moreover, the phase plane analysis highlights the unstable traffic phenomena we are chiefly concerned about and describes the variation of density or velocity with time or sections more clearly.

  12. Introductory note on phase transitions and critical phenomena

    International Nuclear Information System (INIS)

    Yang, C.N.

    1983-01-01

    The author briefly reviews the development of classical statistical mechanics, particularly the contributions of Gibbs. The author then turns to quantum mechanical formulations of phase transitions and critical phenomena, mentioning several seminal works

  13. Dimensional Analysis with space discrimination applied to Fickian difussion phenomena

    International Nuclear Information System (INIS)

    Diaz Sanchidrian, C.; Castans, M.

    1989-01-01

    Dimensional Analysis with space discrimination is applied to Fickian difussion phenomena in order to transform its partial differen-tial equations into ordinary ones, and also to obtain in a dimensionl-ess fom the Ficks second law. (Author)

  14. Conference report for nuclear fusion phenomena in ionized gases

    International Nuclear Information System (INIS)

    Porkolab, M.

    1975-10-01

    A summary of the Conference on Phenomena in Ionized Gases, held in Eindhoven, The Netherlands, is given. In particular, the format of the conference and the content of the review papers are summarized

  15. Computational and experimental investigation of dynamic shock reflection phenomena

    CSIR Research Space (South Africa)

    Naidoo, K

    2007-07-01

    Full Text Available wedge are used to analyse dynamic flow field phenomena and response of the triple point below and within the dual solution domain. Computed, unsteady pressure traces on the reflection plane are also analysed...

  16. Resonances: from nuclear physics to mesoscopic systems

    International Nuclear Information System (INIS)

    Ferreira, Lidia S.; Maglione, Enrico

    2007-01-01

    Resonances are one of the most interesting phenomena in many fields of physics which lead to important findings. In the quantum world, systems with electrons, hadrons or atoms provide enormous amount of data on resonances, leading to the discovery of new states of matter. In nuclear physics, the recent findings on exotic nuclei, added to the list many new examples, which are important not only as direct data on resonances, but also for the production of new isotopes in regions of the nuclear chart which were 'terra incognita', until recently. With recent developments in microelectronics it is possible to create in the laboratory almost two dimensional wave guides where the motion of the electrons can exhibit typical quantum effects. The geometry of systems, such as bends, corners or crosses, has a strong influence on the conduction properties of the electrons, since it can create the appropriate conditions required for the formation of bound states or resonances in the conduction channels. Therefore it is quite important to have an accurate description of the relation between geometry and observables, which in a theoretical perspective emerges naturally from the solution of a multichannel eigenvalue problem. The study of resonances and their behaviour in these domains of physics, will be the purpose of the lecture. (Author)

  17. Multiphotonic resonance processes in potassium vapor

    International Nuclear Information System (INIS)

    Bensoussan, Paul.

    1975-01-01

    Despite several theoretical and experimental investigations, the phenomena of resonance multiphotonic ionization are still not completely understood. The following lines of investigation were undertaken to try and elucidate certain aspects of the resonance processes. The first line of investigation aims at finding the processes which can compete with ionization. Resonance ionization processes can be considered as taking place in two stages: absorption induced excitation of a bound state, followed by photoionization from the excited level. The problem is now to determine what are the processes which compete with the ionization processes starting from a level selectively populated by the absorption of one or two photons. The second line aims at finding the influence of the polarization of the radiation on resonance multiphotonic ionization for the second photon and to check the validity of the selection rules on the magnetic quantic number of the resonance bound linked states. The last study therefore relates to the development of a method of multiphotonic spectrometry which could determine the energy levels in the alcaline f series [fr

  18. Ponderomotive force near cyclotron resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kono, Mitsuo; Sanuki, Heiji

    1987-01-01

    The ponderomotive force, which is involved in the excitation of macroscopic behaviors of plasma caused by wave motion, plays an important role in various non-linear wave motion phenomena. In the present study, equations for the pondermotive force for plasma in a uniform magnetic field is derived using a renormalization theory which is based on the Vlasov equation. It is shown that the pondermotive force, which diverges at the cyclotron resonence point according to adiabatic approximation, can be expressed by a non-divergent equation by taking into account the instability of the cyclotron orbit due to high-order scattering caused by a wave. This is related with chaotic particle behaviors near cyclotron resonance, where the pondermotive force is small and the diffusion process prevails. It is assumed here that the amplitude of the high-frequency electric field is not large and that the broadening of cyclotron levels is smaller than the distance between the levels. A global chaos will be created if the amplitude of the electric field becomes greater to allow the broadening to exceed the distance between the levels. (Nogami, K.).

  19. Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control

    Science.gov (United States)

    2016-07-30

    flames," Physics of Fluids , vol. 7, no. 6, pp. 1447-54, 1995. [8] K. Lyons, " Toward an understanding of the stabilization mechanisms of lifted...Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control This report summarizes the research accomplished in the project...34Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control". The main areas of activity are: a) electrostatic flame and flow

  20. Department of Energy Natural Phenomena Hazards Mitigation program

    International Nuclear Information System (INIS)

    Murray, R.C.

    1993-01-01

    This paper presents a summary of past and present accomplishments of the Natural Phenomena Hazards Program that has been ongoing at Lawrence Livermore National Laboratory since 1975. The Natural Phenomena covered includes earthquake; winds, hurricanes, and tornadoes; flooding and precipitation; lightning; and volcanic events. The work is organized into four major areas (1) Policy, requirements, standards, and guidance, (2) Technical support, research and development, (3) Technology transfer, and (4) Oversight

  1. Ludic Function of Precedent-Related Phenomena in Media Discourse

    Directory of Open Access Journals (Sweden)

    Yu. M. Velykoroda

    2016-12-01

    Full Text Available The aim of this paper is to determine the ludic function of precedent-related phenomena as a type of intertextuality. The analysis is done on the basis of relevance theoretic approach, through which we aim to show the additional cognitive effect which is created by precedent-related phenomena in media discourse, and this comic effect serves as a foundation for the ludic function of these units.

  2. On Process Modelling Using Physical Oriented And Phenomena Based Principles

    Directory of Open Access Journals (Sweden)

    Mihai Culea

    2000-12-01

    Full Text Available This work presents a modelling framework based on phenomena description of the process. The approach is taken to easy understand and construct process model in heterogeneous possible distributed modelling and simulation environments. A simplified case study of a heat exchanger is considered and Modelica modelling language to check the proposed concept. The partial results are promising and the research effort will be extended in a computer aided modelling environment based on phenomena.

  3. Resonant behaviour of MHD waves on magnetic flux tubes. I - Connection formulae at the resonant surfaces. II - Absorption of sound waves by sunspots

    Science.gov (United States)

    Sakurai, Takashi; Goossens, Marcel; Hollweg, Joseph V.

    1991-01-01

    The present method of addressing the resonance problems that emerge in such MHD phenomena as the resonant absorption of waves at the Alfven resonance point avoids solving the fourth-order differential equation of dissipative MHD by recourse to connection formulae across the dissipation layer. In the second part of this investigation, the absorption of solar 5-min oscillations by sunspots is interpreted as the resonant absorption of sounds by a magnetic cylinder. The absorption coefficient is interpreted (1) analytically, under certain simplifying assumptions, and numerically, under more general conditions. The observed absorption coefficient magnitude is explained over suitable parameter ranges.

  4. On Frequency Combs in Monolithic Resonators

    Directory of Open Access Journals (Sweden)

    Savchenkov A. A.

    2016-06-01

    Full Text Available Optical frequency combs have become indispensable in astronomical measurements, biological fingerprinting, optical metrology, and radio frequency photonic signal generation. Recently demonstrated microring resonator-based Kerr frequency combs point the way towards chip scale optical frequency comb generator retaining major properties of the lab scale devices. This technique is promising for integrated miniature radiofrequency and microwave sources, atomic clocks, optical references and femtosecond pulse generators. Here we present Kerr frequency comb development in a historical perspective emphasizing its similarities and differences with other physical phenomena. We elucidate fundamental principles and describe practical implementations of Kerr comb oscillators, highlighting associated solved and unsolved problems.

  5. Molecular Wring Resonances in Chain Molecules

    DEFF Research Database (Denmark)

    Bohr, Henrik; Brunak, Søren; Bohr, Jakob

    1997-01-01

    It is shown that the eigenfrequency of collective twist excitations in chain molecules can be in the megahertz and gigahertz range. Accordingly, resonance states can be obtained at specific frequencies, and phenomena that involve structural properties can take place. Chain molecules can alter the...... their conformation and their ability to function, and a breaking of the chain can result. It is suggested that this phenomenon forms the basis for effects caused by the interaction of microwaves and biomolecules, e.g. microwave assisted hydrolysis of chain molecules....

  6. Quantum resonance for simulating combinatorial problems

    International Nuclear Information System (INIS)

    Zak, Michail; Fijany, Amir

    2005-01-01

    Quantum computing by simulations is based upon similarity between mathematical formalism of a quantum phenomenon and phenomena to be analyzed. In this Letter, the mathematical formalism of quantum resonance combined with tensor product decomposability of unitary evolutions is mapped onto a class of NP-complete combinatorial problems. It has been demonstrated that nature has polynomial resources for solving NP-complete problems and that will help to develop a new strategy for artificial intelligence, as well as to re-evaluate the role of natural selection in biological evolution

  7. On Frequency Combs in Monolithic Resonators

    Science.gov (United States)

    Savchenkov, A. A.; Matsko, A. B.; Maleki, L.

    2016-06-01

    Optical frequency combs have become indispensable in astronomical measurements, biological fingerprinting, optical metrology, and radio frequency photonic signal generation. Recently demonstrated microring resonator-based Kerr frequency combs point the way towards chip scale optical frequency comb generator retaining major properties of the lab scale devices. This technique is promising for integrated miniature radiofrequency and microwave sources, atomic clocks, optical references and femtosecond pulse generators. Here we present Kerr frequency comb development in a historical perspective emphasizing its similarities and differences with other physical phenomena. We elucidate fundamental principles and describe practical implementations of Kerr comb oscillators, highlighting associated solved and unsolved problems.

  8. A simple parameter can switch between different weak-noise-induced phenomena in a simple neuron model

    Science.gov (United States)

    Yamakou, Marius E.; Jost, Jürgen

    2017-10-01

    In recent years, several, apparently quite different, weak-noise-induced resonance phenomena have been discovered. Here, we show that at least two of them, self-induced stochastic resonance (SISR) and inverse stochastic resonance (ISR), can be related by a simple parameter switch in one of the simplest models, the FitzHugh-Nagumo (FHN) neuron model. We consider a FHN model with a unique fixed point perturbed by synaptic noise. Depending on the stability of this fixed point and whether it is located to either the left or right of the fold point of the critical manifold, two distinct weak-noise-induced phenomena, either SISR or ISR, may emerge. SISR is more robust to parametric perturbations than ISR, and the coherent spike train generated by SISR is more robust than that generated deterministically. ISR also depends on the location of initial conditions and on the time-scale separation parameter of the model equation. Our results could also explain why real biological neurons having similar physiological features and synaptic inputs may encode very different information.

  9. Mechanism of Occurring Over-Voltage Phenomena in Distributed Power System on Energization of Transformers

    Science.gov (United States)

    Nakachi, Yoshiki; Ueda, Fukashi; Kajikawa, Takuya; Amau, Tooru; Kameyama, Hirokazu; Ito, Hisanori

    This paper verifies the mechanism of occurring over voltage phenomena in the distributed power system on energizing the transformer. This over-voltage, which is observed at the actual distributed power system, with heavy inrush current is found to occur at about 0.1-0.2sec after the energizing and continue for a duration of more than 0.1[sec]. There is a concern that this over-voltage may operate the protection relay and deteriorate the insulation of apparatus. It is basically caused by the resonance between the shunt capacitors and saturated/unsaturated magnetizing inductance of transformer, system inductance. By using analytical formulation of a simple equivalent circuit, its mechanism has been verified through simulations carried out by using EMTP. Moreover, the sympathetic interaction between transformers is prolonged the duration of the over-voltage by the field test data is discussed in this paper.

  10. Effects of the Hot Alignment of a Power Unit on Oil-Whip Instability Phenomena

    Directory of Open Access Journals (Sweden)

    A. Vania

    2010-01-01

    Full Text Available This paper shows the results of the analysis of the dynamic behaviour of a power unit, whose shaft-train alignment was significantly influenced by the machine thermal state, that was affected in operating condition by high subsynchronous vibrations caused by oil-whip instability phenomena. The dynamic stiffness coefficients of the oil-film journal bearings of the generator were evaluated considering the critical average journal positions that caused the instability onsets. By including these bearing coefficients in a mathematical model of the fully assembled machine, the real part of the eigenvalue associated with the first balance resonance of the generator rotor became positive. This paper shows the successful results obtained by combining diagnostic techniques based on mathematical models of journal bearings and shaft train with detailed analyses of monitoring data aimed to investigate the effects of the hot alignment of rotating machines on the occurrence of oil-whip instability onsets.

  11. Precise Measurements of the Density and Critical Phenomena Near Phase Transitions in Liquid Helium

    Science.gov (United States)

    Yeh, Nai-Chang

    1997-01-01

    The first-year progress for the project of precise measurements of the density and critical phenomena of helium near phase transitions is summarized below: (1) completion of a cryogenic sample probe for the proposed measurements, and the rehabilitation of a designated laboratory at Caltech for this project; (2) construction and testing of a superconducting niobium cavity; (3) acquisition of one phase-locked-loop system for high-resolution frequency control and read- out; (4) setting up high-resolution thermometry (HRT) for temperature readout and control; (5) developing new approaches for calibrating the coefficient between the resonant frequency shift (delta f) and the helium density (rho), as well as for measuring the effect of gravity on T(sub lambda) to a much better precision; (6) programming of the interface control of all instruments for automatic data acquisition; and (7) improving data analyses and fitting procedures.

  12. Equal-potential interpretation of electrically induced resonances in metamaterials

    DEFF Research Database (Denmark)

    Peng, Liang; Mortensen, N. Asger

    2011-01-01

    We propose a general description of electrically induced resonances (EIR) in metamaterials (MMs) comprising subwavelength unit cells. Based on classical electrodynamics, we found that EIR is governed by an equal-potential effect. Our theory accounts for the EIR phenomena and can give a renewed...... definition of the effective electric field and hence effective permittivity for MMs made of either dielectrics or metals as well as combinations thereof. The EIR, inherent to the periodic structures, may be the unifying origin of recently observed anomalous electromagnetic phenomena, e.g. the enhanced...

  13. Crossing simple resonances

    International Nuclear Information System (INIS)

    Collins, T.

    1985-08-01

    A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances

  14. Acoustic Fano resonators

    KAUST Repository

    Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

    2014-01-01

    The resonances with asymmetric Fano line-shapes were originally discovered in the context of quantum mechanics (U. Fano, Phys. Rev., 124, 1866-1878, 1961). Quantum Fano resonances were generated from destructive interference of a discrete state

  15. Neutron resonance averaging

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1986-10-01

    The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

  16. Crossing simple resonances

    Energy Technology Data Exchange (ETDEWEB)

    Collins, T.

    1985-08-01

    A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.

  17. Microscopic Linear Response Theory of Spin Relaxation and Relativistic Transport Phenomena in Graphene

    Directory of Open Access Journals (Sweden)

    Manuel Offidani

    2018-05-01

    Full Text Available We present a unified theoretical framework for the study of spin dynamics and relativistic transport phenomena in disordered two-dimensional Dirac systems with pseudospin-spin coupling. The formalism is applied to the paradigmatic case of graphene with uniform Bychkov-Rashba interaction and shown to capture spin relaxation processes and associated charge-to-spin interconversion phenomena in response to generic external perturbations, including spin density fluctuations and electric fields. A controlled diagrammatic evaluation of the generalized spin susceptibility in the diffusive regime of weak spin-orbit interaction allows us to show that the spin and momentum lifetimes satisfy the standard Dyakonov-Perel relation for both weak (Gaussian and resonant (unitary nonmagnetic disorder. Finally, we demonstrate that the spin relaxation rate can be derived in the zero-frequency limit by exploiting the SU(2 covariant conservation laws for the spin observables. Our results set the stage for a fully quantum-mechanical description of spin relaxation in both pristine graphene samples with weak spin-orbit fields and in graphene heterostructures with enhanced spin-orbital effects currently attracting much attention.

  18. Magnetic resonance imaging of valvular heart disease

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Ståhlberg, F; Thomsen, C

    1999-01-01

    The optimum management of patients with valvular heart diseases requires accurate and reproducible assessment of the valvular lesion and its hemodynamic consequences. Magnetic resonance imaging (MRI) techniques, such as volume measurements, signal-void phenomena, and velocity mapping, can be used...... in an integrated approach to gain qualitative and quantitative information on valvular heart disease as well as ventricular dimensions and functions. Thus, MRI may be advantageous to the established diagnostic tools in assessing the severity of valvular heart disease as well as monitoring the lesion and predicting...... the optimal timing for valvular surgery. This paper reviews the validation of these MRI techniques in assessing valvular heart disease and discusses some typical pitfalls of the techniques, including suggestions for solutions.J. Magn. Reson. Imaging 1999;10:627-638....

  19. PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

    Science.gov (United States)

    Eikerling, Michael

    2011-06-01

    Proton transport phenomena are of paramount importance for acid-base chemistry, energy transduction in biological organisms, corrosion processes, and energy conversion in electrochemical systems such as polymer electrolyte fuel cells. The relevance for such a plethora of materials and systems, and the ever-lasting fascination with the highly concerted nature of underlying processes drive research across disciplines in chemistry, biology, physics and chemical engineering. A proton never travels alone. Proton motion is strongly correlated with its environment, usually comprised of an electrolyte and a solid or soft host material. For the transport in nature's most benign proton solvent and shuttle, water that is, insights from ab initio simulations, matured over the last 15 years, have furnished molecular details of the structural diffusion mechanism of protons. Excess proton movement in water consists of sequences of Eigen-Zundel-Eigen transitions, triggered by hydrogen bond breaking and making in the surrounding water network. Nowadays, there is little debate about the validity of this mechanism in water, which bears a stunning resemblance to the basic mechanistic picture put forward by de Grotthuss in 1806. While strong coupling of an excess proton with degrees of freedom of solvent and host materials facilitates proton motion, this coupling also creates negative synergies. In general, proton mobility in biomaterials and electrochemical proton conducting media is highly sensitive to the abundance and structure of the proton solvent. In polymer electrolyte membranes, in which protons are bound to move in nano-sized water-channels, evaporation of water or local membrane dehydration due to electro-osmotic coupling are well-known phenomena that could dramatically diminish proton conductivity. Contributions in this special issue address various vital aspects of the concerted nature of proton motion and they elucidate important structural and dynamic effects of solvent

  20. Comprehending emergent systems phenomena through direct-manipulation animation

    Science.gov (United States)

    Aguirre, Priscilla Abel

    This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios

  1. Pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Cohen, M.D.

    1986-01-01

    This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

  2. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  3. New innershell phenomena from Rydberg series of highly charged ions

    International Nuclear Information System (INIS)

    Rosmej, F.B.

    1997-01-01

    Dielectronic satellite spectra near the He-like resonance line W are investigated experimentally and theoretically. We propose that under certain plasma conditions the resonance line structure plays a minor role and can be mixed with the accumulation of Rydberg satellites. (orig.)

  4. New innershell phenomena from Rydberg series of highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Rosmej, F.B. [Bochum Univ. (Germany). Inst. fuer Experimentalphysik; Faenov, A.Ya. [MISDC, VNIIFTRI, Mendeleevo (Russian Federation)

    1997-12-31

    Dielectronic satellite spectra near the He-like resonance line W are investigated experimentally and theoretically. We propose that under certain plasma conditions the resonance line structure plays a minor role and can be mixed with the accumulation of Rydberg satellites. (orig.). 7 refs.

  5. The Center for Natural Phenomena Engineering (CNPE), 1990--1991

    International Nuclear Information System (INIS)

    1992-07-01

    The Center for Natural Phenomena Engineering (CNPE) was established to provide a natural phenomena (NP) engineering oversight role within Martin Marietta Energy Systems, Inc. (MMES). In this oversight role CNPE's goals are to provide coordination and direction of activities related to earthquake and other natural phenomena engineering, including development of hazard definition, development of design criteria, conducting new facility design, development and conducting of testing, performance of analysis and vulnerability studies, development of analysis methodology, and provision of support for preparation of safety analysis reports for the five MMES sites. In conducting these activities it is CNPE's goal to implement the elements of Total Quality Management (TQM) in a cost-effective manner, providing its customers with a quality product. This report describes 1990--1991 activities

  6. Nonlinear Magnetic Phenomena in Highly Polarized Target Materials

    CERN Document Server

    Kiselev, Yu F

    2007-01-01

    The report introduces and surveys nonlinear magnetic phenomena which have been observed at high nuclear polarizations in polarized targets of the SMC and of the COMPASS collaborations at CERN. Some of these phenomena, namely the frequency modulation eect and the distortion of the NMR line shape, promote the development of the polarized target technique. Others, as the spin-spin cross-relaxation between spin subsystems can be used for the development of quantum statistical physics. New findings bear on an electromagnetic noise and the spectrally resolved radiation from LiD with negatively polarized nuclei detected by low temperature bolometers. These nonlinear phenomena need to be taken into account for achieving the ultimate polarizations.

  7. The Center for Natural Phenomena Engineering (CNPE), 1990--1991

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-07-01

    The Center for Natural Phenomena Engineering (CNPE) was established to provide a natural phenomena (NP) engineering oversight role within Martin Marietta Energy Systems, Inc. (MMES). In this oversight role CNPE`s goals are to provide coordination and direction of activities related to earthquake and other natural phenomena engineering, including development of hazard definition, development of design criteria, conducting new facility design, development and conducting of testing, performance of analysis and vulnerability studies, development of analysis methodology, and provision of support for preparation of safety analysis reports for the five MMES sites. In conducting these activities it is CNPE`s goal to implement the elements of Total Quality Management (TQM) in a cost-effective manner, providing its customers with a quality product. This report describes 1990--1991 activities.

  8. Random phenomena fundamentals of probability and statistics for engineers

    CERN Document Server

    Ogunnaike, Babatunde A

    2009-01-01

    PreludeApproach PhilosophyFour Basic PrinciplesI FoundationsTwo Motivating ExamplesYield Improvement in a Chemical ProcessQuality Assurance in a Glass Sheet Manufacturing ProcessOutline of a Systematic ApproachRandom Phenomena, Variability, and UncertaintyTwo Extreme Idealizations of Natural PhenomenaRandom Mass PhenomenaIntroducing ProbabilityThe Probabilistic FrameworkII ProbabilityFundamentals of Probability TheoryBuilding BlocksOperationsProbabilityConditional ProbabilityIndependenceRandom Variables and DistributionsDistributionsMathematical ExpectationCharacterizing DistributionsSpecial Derived Probability FunctionsMultidimensional Random VariablesDistributions of Several Random VariablesDistributional Characteristics of Jointly Distributed Random VariablesRandom Variable TransformationsSingle Variable TransformationsBivariate TransformationsGeneral Multivariate TransformationsApplication Case Studies I: ProbabilityMendel and HeredityWorld War II Warship Tactical Response Under AttackIII DistributionsIde...

  9. Biomedical Signals and Sensors I Linking Physiological Phenomena and Biosignals

    CERN Document Server

    Kaniusas, Eugenijus

    2012-01-01

    This two-volume set focuses on the interface between physiologic mechanisms and diagnostic human engineering. Today numerous biomedical sensors are commonplace in clinical practice. The registered biosignals reflect mostly vital physiologic phenomena. In order to adequately apply biomedical sensors and reasonably interpret the corresponding biosignals, a proper understanding of the involved physiologic phenomena, their influence on the registered biosignals, and the technology behind the sensors is necessary. The first volume is devoted to the interface between physiologic mechanisms and arising biosignals, whereas the second volume is focussed on the interface between biosignals and biomedical sensors. The physiologic mechanisms behind the biosignals are described from the basic cellular level up to their advanced mutual coordination level during sleep. The arising biosignals are discussed within the scope of vital physiologic phenomena to foster their understanding and comprehensive analysis.

  10. Modified Phenomena Identification and Ranking Table (PIRT) for Uncertainty Analysis

    International Nuclear Information System (INIS)

    Gol-Mohamad, Mohammad P.; Modarres, Mohammad; Mosleh, Ali

    2006-01-01

    This paper describes a methodology of characterizing important phenomena, which is also part of a broader research by the authors called 'Modified PIRT'. The methodology provides robust process of phenomena identification and ranking process for more precise quantification of uncertainty. It is a two-step process of identifying and ranking methodology based on thermal-hydraulics (TH) importance as well as uncertainty importance. Analytical Hierarchical Process (AHP) has been used for as a formal approach for TH identification and ranking. Formal uncertainty importance technique is used to estimate the degree of credibility of the TH model(s) used to represent the important phenomena. This part uses subjective justification by evaluating available information and data from experiments, and code predictions. The proposed methodology was demonstrated by developing a PIRT for large break loss of coolant accident LBLOCA for the LOFT integral facility with highest core power (test LB-1). (authors)

  11. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  12. Quantum mechanical resonances

    International Nuclear Information System (INIS)

    Cisneros S, A.; McIntosh, H.V.

    1982-01-01

    A discussion of the nature of quantum mechanical resonances is presented from the point of view of the spectral theory of operators. In the case of Bohr-Feshbach resonances, graphs are presented to illustrate the theory showing the decay of a doubly excited metastable state and the excitation of the resonance by an incident particle with proper energy. A characterization of resonances is given as well as a procedure to determine widths using the spectral density function. A sufficient condition is given for the validity of the Breit-Wigner formula for Bohr-Feshbach resonances. (author)

  13. Polariton condensation, superradiance and difference combination parametric resonance in mode-locked laser

    Science.gov (United States)

    Bagayev, S. N.; Arkhipov, R. M.; Arkhipov, M. V.; Egorov, V. S.; Chekhonin, I. A.; Chekhonin, M. A.

    2017-11-01

    The generation of the ring mode-locked laser containing resonant absorption medium in the cavity was investigated. It is shown that near the strong resonant absorption lines a condensation of polaritons arises. Intensive radiation looks like as superradiance in a medium without population inversion. We studied theoretically the microscopic mechanism of these phenomena. It was shown that in this system in absorbing medium a strong self-induced difference combination parametric resonance exists. Superradiance on polaritonic modes in the absorbing medium are due to the emergence of light-induced resonant polarization as a result of fast periodic nonadiabatic quantum jumps in the absorber.

  14. Thermionic phenomena the collected works of Irving Langmuir

    CERN Document Server

    Suits, C Guy

    1961-01-01

    Thermionic Phenomena is the third volume of the series entitled The Collected Works of Irving Langmuir. This volume compiles articles written during the 1920's and early 1930's, the period when the science of thermionics is beginning to be of importance. This text is divided into two parts. The first part discusses vacuum pumps, specifically examining the effect of space charge and residual gases on thermionic currents in high vacuum. This part also explains fundamental phenomena in electron tubes having tungsten cathodes and the use of high-power vacuum tubes. The second part of this text loo

  15. Simulation of water hammer phenomena using the system code ATHLET

    Energy Technology Data Exchange (ETDEWEB)

    Bratfisch, Christoph; Koch, Marco K. [Bochum Univ. (Germany). Reactor Simulation and Safety Group

    2017-07-15

    Water Hammer Phenomena can endanger the integrity of structures leading to a possible failure of pipes in nuclear power plants as well as in many industrial applications. These phenomena can arise in nuclear power plants in the course of transients and accidents induced by the start-up of auxiliary feed water systems or emergency core cooling systems in combination with rapid acting valves and pumps. To contribute to further development and validation of the code ATHLET (Analysis of Thermalhydraulics of Leaks and Transients), an experiment performed in the test facility Pilot Plant Pipework (PPP) at Fraunhofer UMSICHT is simulated using the code version ATHLET 3.0A.

  16. Time in powers of ten natural phenomena and their timescales

    CERN Document Server

    't Hooft, Gerard

    2014-01-01

    In this richly illustrated book, Nobel Laureate Gerard 't Hooft and Theoretical Physicist Stefan Vandoren describe the enormous diversity of natural phenomena that take place at different time scales. In the tradition of the bestseller Powers of Ten , the authors zoom in and out in time, each step with a factor of ten. Starting from one second, time scales are enlarged until processes are reached that take much longer than the age of the universe. After the largest possible eternities, the reader is treated to the shortest and fastest phenomena known. Then the authors increase with powers of t

  17. RELAP5-3D code validation for RBMK phenomena

    International Nuclear Information System (INIS)

    Fisher, J.E.

    1999-01-01

    The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena

  18. Simulation of water hammer phenomena using the system code ATHLET

    International Nuclear Information System (INIS)

    Bratfisch, Christoph; Koch, Marco K.

    2017-01-01

    Water Hammer Phenomena can endanger the integrity of structures leading to a possible failure of pipes in nuclear power plants as well as in many industrial applications. These phenomena can arise in nuclear power plants in the course of transients and accidents induced by the start-up of auxiliary feed water systems or emergency core cooling systems in combination with rapid acting valves and pumps. To contribute to further development and validation of the code ATHLET (Analysis of Thermalhydraulics of Leaks and Transients), an experiment performed in the test facility Pilot Plant Pipework (PPP) at Fraunhofer UMSICHT is simulated using the code version ATHLET 3.0A.

  19. Randomly transitional phenomena in the system governed by Duffing's equation

    International Nuclear Information System (INIS)

    Ueda, Yoshisuke.

    1978-06-01

    This paper deals with turbulent or chaotic phenomena which occur in the system governed by Duffing's equation, a special type of 2-dimensional periodic systems. By using analog and digital computers, experiments are undertaken with special reference to the changes of attractors and of average power spectra of the random processes under the variation of the system parameters. On the basis of the experimental results, an outline of the random process is made clear. The results obtained in this paper will be applied to the phenomena of the same kind which occur in 3-dimensional autonomous systems. (author)

  20. Psychosocial Aspects of Dental Anxiety and Clinical Pain Phenomena

    DEFF Research Database (Denmark)

    Moore, Rod

    This Danish Doctoral Dissertation in the science of Odontology contains 7 chapters: 1) Introduction to a social perspective on dental treatment, anxiety and pain throughout time, 2) research models and methods to study dental anxiety and clinical pain phenomena, 3) the fear of dental treatment...... .. what it is and what it is not and how many have it, 4) clinical pain treatment, psychosocial aspects in relation to anxiety, 4) patients and dentists' roles, pain perception and anxiety, 6) psychosocial aspects of managing anxiety and pain phenomena, and 7) Conclusions and proposals for the future...

  1. Transport phenomena in Newtonian fluids a concise primer

    CERN Document Server

    Olsson, Per

    2013-01-01

    This short primer provides a concise and tutorial-style introduction to transport phenomena in Newtonian fluids , in particular the transport of mass, energy and momentum.  The reader will find detailed derivations of the transport equations for these phenomena, as well as selected analytical solutions to the transport equations in some simple geometries. After a brief introduction to the basic mathematics used in the text, Chapter 2, which deals with momentum transport, presents a derivation of the Navier-Stokes-Duhem equation describing the basic flow in a Newtonian fluid.  Also provided at

  2. Formation and coupling of band gaps in a locally resonant elastic system comprising a string with attached resonators

    International Nuclear Information System (INIS)

    Xiao Yong; Mace, Brian R.; Wen Jihong; Wen Xisen

    2011-01-01

    A uniform string with periodically attached spring-mass resonators represents a simple locally resonant continuous elastic system whose band gap mechanisms are basic to more general and complicated problems. In this Letter, analytical models with explicit formulations are provided to understand the band gap mechanisms of such a system. Some interesting phenomena are demonstrated and discussed, such as asymmetric/symmetric attenuation behavior within a resonance gap, and the realization of a super-wide gap due to exact coupling between Bragg and resonance gaps. In addition, some approximate formulas for the evaluation of low frequency resonance gaps are derived using an approach different from existing investigations. - Research highlights: → We examine band gaps in a special one-dimensional locally resonant system. → Bragg and resonance gaps co-exist. → Explicit formulas for locating band edges are derived. → Exact physical models are used to clarify the band gap formation mechanisms. → Coupling between Bragg and resonance gaps leads to a super-wide gap.

  3. Microstrip resonators for electron paramagnetic resonance experiments

    Science.gov (United States)

    Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.

    2009-07-01

    In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

  4. Microstrip resonators for electron paramagnetic resonance experiments.

    Science.gov (United States)

    Torrezan, A C; Mayer Alegre, T P; Medeiros-Ribeiro, G

    2009-07-01

    In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5 x 10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

  5. R-ES-ONANCE

    Indian Academy of Sciences (India)

    Gems: Objects of Aesthetic Beauty and Scientific Curiosity. ~f). "*=-'d ... his interests on the many beautiful optical phenomena gems exhibit and, with his discoveries, enriched ... and the potential for a new generation of electronic devices.

  6. Teaching Resonance and Harmonics with Guitar and Piano1

    Science.gov (United States)

    Sobel, Michael

    2014-02-01

    In a recent paper,2 Kasar, Yurumezoglu, and Sengoren show how to use a guitar, or two guitars, to demonstrate resonance. Here we extend this idea by showing how to use a guitar or a piano (both acoustic) to demonstrate resonance, harmonics, and the properties of the musical scale. We discuss the advantages and disadvantages of each instrument. Students who know something about music can get a little more out of these demonstrations than others, but all students will observe some important and interesting phenomena in an everyday setting.

  7. The fusion rate in the transmission resonance model

    International Nuclear Information System (INIS)

    Jaendel, M.

    1992-01-01

    Resonant transmission of deuterons through a chain of target deuterons in a metal matrix has been suggested as an explanation for the cold fusion phenomena. In this paper the fusion rate in such transmission resonance models is estimated, and the basic physical constraints are discussed. The dominating contribution to the fusion yield is found to come from metastable states. The fusion rate is well described by the Wentzel-Kramer-Brillouin approximation and appears to be much too small to explain the experimental anomalies

  8. Tools and methods for teaching magnetic resonance concepts and techniques

    DEFF Research Database (Denmark)

    Hanson, Lars G.

    2012-01-01

    Teaching of MRI methodology can be challenging for teachers as well as students. To support student learning, two graphical simulators for exploration of basic magnetic resonance principles are here introduced. The first implements a simple compass needle analogy implemented for day one of NMR...... and MRI education. After a few minutes of use, any user with minimal experience of magnetism will be able to explain the basic magnetic resonance principle. A second piece of software, the Bloch Simulator, aims much further, as it can be used to demonstrate and explore a wide range of phenomena including...

  9. New high-energy phenomena in aircraft triggered lightning

    NARCIS (Netherlands)

    van Deursen, A.P.J.; Kochkin, P.; de Boer, A.; Bardet, M.; Boissin, J.F.

    2016-01-01

    High-energy phenomena associated with lighting have been proposed in the twenties, observed for the first time in the sixties, and further investigated more recently by e.g. rocket triggered lightning. Similarly, x-rays have been detected in meter-long discharges in air at standard atmospheric

  10. All basic condensed matter physics phenomena and notions mirror ...

    Indian Academy of Sciences (India)

    biology an opportunity to explore a variety of condensed matter phenomena and situations, some of which have ... The biological matter such as the tiniest of life, an amoeba, is alive ..... and black-holes, nature fascinates physicists. It is the ...

  11. Observation of diffusion phenomena of liquid phase with multiple components

    International Nuclear Information System (INIS)

    Eguchi, Wataru

    1979-01-01

    The diffusion phenomena of liquid phase with multiple components was directly observed, and the factors contributing to complex material transfer were investigated, comparing to the former experimental results. The most excellent method of observing the diffusion behavior of liquid phase used heretofore is to trace the time history of concentration distribution for each component in unsteady diffusion process. The method of directly observing the concentration distribution is usually classified into the analysis of diffused samples, the checking of radioactive isotope tracers, and the measurement of light refraction and transmission. The most suitable method among these is to trace this time history by utilizing the spectrophotometer of position scanning type. An improved spectrophotometer was manufactured for trial. The outline of the measuring system and the detail of the optical system of this new type spectrophotometer are explained. The resolving power for position measurement is described with the numerical calculation. As for the observation examples of the diffusion phenomena of liquid phase with multiple components, the diffusion of multiple electrolytes in aqueous solution, the observation of the material transfer phenomena accompanied by heterogeneous and single phase chemical reaction, and the observation of concentration distribution in the liquid diaphragm in a reaction absorption system are described. For each experimental item, the test apparatus, the sample material, the test process, the test results and the evaluation are explained in detail, and the diffusion phenomena of liquid phase with multiple components were pretty well elucidated. (Nakai, Y.)

  12. Developing Critical Thinking through the Study of Paranormal Phenomena.

    Science.gov (United States)

    Wesp, Richard; Montgomery, Kathleen

    1998-01-01

    Argues that accounts of paranormal phenomena can serve as an ideal medium in which to encourage students to develop critical-thinking skills. Describes a cooperative-learning approach used to teach critical thinking in a course on paranormal events. Reports that critical-thinking skills increased and that the course received favorable student…

  13. Damage phenomena at target surface by small leak

    International Nuclear Information System (INIS)

    Jeong, Kyung Chai; Jeong, J. Y.; Kim, B. H.; Kim, T. J.; Choi, J. H.

    2001-04-01

    Design of the steam generator should be considered the safety about the sodium-water reaction occurred by water leak in heat transfer tube. Water leak mainly occurred from welding defect at the process of tube connection, the vibration of heat transfer tube bundle in steam generating system, fretting, and pin hole in original tube manufacturing. The classification of water leak divided to two parts, roughly, in case of the water leak studies. One is small leak phenomena analysis, and the other is it of large leak which was mainly treated to the evaluation on pressure increasing from hydrogen gas formed by sodium-water reaction in sodium system. In small water leak, the leak propagation phenomena and the development of leak detecting system at initial stage of small water leak were studied, mainly. In this study, the corrosion phenomena on the target tube surface appeared by sodium-water reaction was analyzed through the small water leak experiments, and, also, the jet phenomena formed by N 2 gas injection through the leak nozzle under water medium was observed

  14. The theory of critical phenomena in two-dimensional systems

    International Nuclear Information System (INIS)

    Olvera de la C, M.

    1981-01-01

    An exposition of the theory of critical phenomena in two-dimensional physical systems is presented. The first six chapters deal with the mean field theory of critical phenomena, scale invariance of the thermodynamic functions, Kadanoff's spin block construction, Wilson's renormalization group treatment of critical phenomena in configuration space, and the two-dimensional Ising model on a triangular lattice. The second part of this work is made of four chapters devoted to the application of the ideas expounded in the first part to the discussion of critical phenomena in superfluid films, two-dimensional crystals and the two-dimensional XY model of magnetic systems. Chapters seven to ten are devoted to the following subjects: analysis of long range order in one, two, and three-dimensional physical systems. Topological defects in the XY model, in superfluid films and in two-dimensional crystals. The Thouless-Kosterlitz iterated mean field theory of the dipole gas. The renormalization group treatment of the XY model, superfluid films and two-dimensional crystal. (author)

  15. Phenomena of g-u symmetry-breakdown in HD

    NARCIS (Netherlands)

    de Lange, A.; Reinhold, E.M.; Ubachs, W.M.G.

    2002-01-01

    Phenomena associated with the breakdown of inversion symmetry in the HD molecule are reviewed and discussed. A distinction is made between three kinds of physical effects observed in HD spectra. The existence of a small electric dipole moment in the ground state gives rise to vibrational and pure

  16. Eighty phenomena about the self: representation, evaluation, regulation, and change

    Science.gov (United States)

    Thagard, Paul; Wood, Joanne V.

    2015-01-01

    We propose a new approach for examining self-related aspects and phenomena. The approach includes (1) a taxonomy and (2) an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation). The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation). The changing self is less time-limited than the effecting self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development). Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular). We illustrate our approach by focusing on seven self-related phenomena. PMID:25870574

  17. Searches for phenomena beyond the Standard Model at the Large

    Indian Academy of Sciences (India)

    The LHC has delivered several fb-1 of data in spring and summer 2011, opening new windows of opportunity for discovering phenomena beyond the Standard Model. A summary of the searches conducted by the ATLAS and CMS experiments based on about 1 fb-1 of data is presented.

  18. Eighty Phenomena About the Self: Representation, Evaluation, Regulation, and Change

    Directory of Open Access Journals (Sweden)

    Paul eThagard

    2015-03-01

    Full Text Available We propose a new approach for examining self-related aspects and phenomena. The approach includes (1 a taxonomy and (2 an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation. The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation. The changing self is less time-limited than the regulating self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development. Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular. We illustrate our approach by focusing on seven self-related phenomena.

  19. Wave propagation phenomena in metamaterials for retrieving of effective parameters

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Ha, S.

    2011-01-01

    In the talk we give an overview of the developed restoration procedures and discuss their pros and cons in connection of assigning effective parameters (EP) to metamaterials (MMs). There are plenty of notorious physical phenomena preserving the unambiguous retrieving of EP, like strong coupling...

  20. Phenomena identification and ranking tables (PIRT) for LBLOCA

    International Nuclear Information System (INIS)

    Shaw, R.A.; Dimenna, R.A.; Larson, T.K.; Wilson, G.E.

    1988-01-01

    The US Nuclear Regulatory Commission is sponsoring a program to provide validated reactor safety computer codes with quantified uncertainties. The intent is to quantify the accuracy of the codes for use in best estimate licensing applications. One of the tasks required to complete this program involves the identification and ranking of thermal-hydraulic phenomena that occur during particular accidents. This paper provides detailed tables of phenomena and importance ranks for a PWR LBLOCA. The phenomena were identified and ranked according to perceived impact on peak cladding temperature. Two approaches were used to complete this task. First, a panel of experts identified the physical processes considered to be most important during LBLOCA. A second team of experienced analysts then, in parallel, assembled complete tables of all plausible LBLOCA phenomena, regardless of perceived importance. Each phenomenon was then ranked in importance against every other phenomenon associated with a given component. The results were placed in matrix format and solved for the principal eigenvector. The results as determined by each method are presented in this report

  1. On some phenomena concerning pregnancy and parturition of the Cetacea

    NARCIS (Netherlands)

    Slijper, E.J.

    1949-01-01

    1. A review is given of some phenomena concerning pregnancy and parturition of the Cetacea, depending on data in literature and on observations made in Antarctic Blue and Fin Whales on board the f.f. “Willem Barendsz” (1946—1947). 2. In Mystacoceti the frequency of twins appears to be less than in

  2. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  3. Maxwell Prize Talk: Scaling Laws for the Dynamical Plasma Phenomena

    Science.gov (United States)

    Ryutov, Livermore, Ca 94550, Usa, D. D.

    2017-10-01

    The scaling and similarity technique is a powerful tool for developing and testing reduced models of complex phenomena, including plasma phenomena. The technique has been successfully used in identifying appropriate simplified models of transport in quasistationary plasmas. In this talk, the similarity and scaling arguments will be applied to highly dynamical systems, in which temporal evolution of the plasma leads to a significant change of plasma dimensions, shapes, densities, and other parameters with respect to initial state. The scaling and similarity techniques for dynamical plasma systems will be presented as a set of case studies of problems from various domains of the plasma physics, beginning with collisonless plasmas, through intermediate collisionalities, to highly collisional plasmas describable by the single-fluid MHD. Basic concepts of the similarity theory will be introduced along the way. Among the results discussed are: self-similarity of Langmuir turbulence driven by a hot electron cloud expanding into a cold background plasma; generation of particle beams in disrupting pinches; interference between collisionless and collisional phenomena in the shock physics; similarity for liner-imploded plasmas; MHD similarities with an emphasis on the effect of small-scale (turbulent) structures on global dynamics. Relations between astrophysical phenomena and scaled laboratory experiments will be discussed.

  4. Light-induced phenomena in polymeric thin films

    Czech Academy of Sciences Publication Activity Database

    Nešpůrek, Stanislav; Pospíšil, Jan

    2005-01-01

    Roč. 7, č. 3 (2005), s. 1157-1168 ISSN 1454-4164 R&D Projects: GA MŠk ME 700 Institutional research plan: CEZ:AV0Z40500505 Keywords : Light-induced phenomena * photodegradation * photochromism Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.138, year: 2005

  5. Extreme wave phenomena in down-stream running modulated waves

    NARCIS (Netherlands)

    Andonowati, A.; Karjanto, N.; van Groesen, Embrecht W.C.

    Modulational, Benjamin-Feir, instability is studied for the down-stream evolution of surface gravity waves. An explicit solution, the soliton on finite background, of the NLS equation in physical space is used to study various phenomena in detail. It is shown that for sufficiently long modulation

  6. Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

    Science.gov (United States)

    Lumetta, Gregg J.; Arcia, Edgar

    2016-01-01

    A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as…

  7. Deriving Case, Agreement and Voice Phenomena in Syntax

    Science.gov (United States)

    Sigurdsson, Einar Freyr

    2017-01-01

    This dissertation places case, agreement and Voice phenomena in syntax. It argues that the derivation is driven by so-called derivational features, that is, structure-building features (Merge) and probe features (Agree) (Heck and Muller 2007 and Muller 2010; see also Chomsky 2000, 2001). Both types are essential in deriving case and agreement in…

  8. Electrocapillary Phenomena at Edible Oil/Saline Interfaces.

    Science.gov (United States)

    Nishimura, Satoshi; Ohzono, Takuya; Shoji, Kohei; Yagihara, Shin; Hayashi, Masafumi; Tanaka, Hisao

    2017-03-01

    Interfacial tension between edible oil and saline was measured under applied electric fields to understand the electrocapillary phenomena at the edible oil/saline interfaces. The electric responses of saline droplets in edible oil were also observed microscopically to examine the relationship between the electrocapillary phenomena and interfacial polarization. When sodium oleate (SO) was added to edible oil (SO-oil), the interfacial tension between SO-oil and saline decreased. However, no decrease was observed for additive-free oil or oleic acid (OA)-added oil (OA-oil). Microscopic observations suggested that the magnitude of interfacial polarization increased in the order of additive-free oil oil oil. The difference in electrocapillary phenomena between OA- and SO-oils was closely related to the polarization magnitude. In the case of SO-oil, the decrease in interfacial tension was remarkably larger for saline (pH 5.4~5.6) than that for phosphate-buffered saline (PBS, pH 7.2~7.4). However, no difference was observed between the electric responses of PBS and saline droplets in SO-oil. The difference in electrocapillary phenomena for PBS and saline could not be simply explained in terms of polarization magnitude. The ratio of ionized and non-ionized OA at the interfaces changed with the saline pH, possibly leading to the above difference.

  9. Nuclear chromodynamics: Novel nuclear phenomena predicted by QCD

    NARCIS (Netherlands)

    Bakker, B.L.G.; Ji, C.R.

    2014-01-01

    With the acceptance of QCD as the fundamental theory of strong interactions, one of the basic problems in the analysis of nuclear phenomena became how to consistently account for the effects of the underlying quark/gluon structure of nucleons and nuclei. Besides providing more detailed understanding

  10. Negative feedback phenomena in InP-based hydrogen detectors

    Czech Academy of Sciences Publication Activity Database

    Šrobár, Fedor; Procházková, Olga

    2012-01-01

    Roč. 6, 11-12 (2012), s. 1089-1091 ISSN 1842-6573 R&D Projects: GA ČR GA102/09/1037 Institutional support: RVO:67985882 Keywords : Chemical sensors * Interface phenomena * Semiconductor devices Subject RIV: JA - Electronics ; Optoelectronics , Electrical Engineering Impact factor: 0.402, year: 2012

  11. Mechanical breakdown in the nuclear multifragmentation phenomena. Thermodynamic analysis

    International Nuclear Information System (INIS)

    Bulavin, L.A.; Cherevko, K.V.; Sysoev, V.M.

    2012-01-01

    Based on a similarity of the Van der Waals and nucleon-nucleon interaction the known thermodynamic relations for ordinary liquids are used to analyze the possible decay channels in the proton induced nuclear multifragmentation phenomena. The main features of the different phase trajectories in the P-V plane are compared with the experimental data on multifragmentation. It allowed choosing the phase trajectories with the correct qualitative picture of the phenomena. Based on the thermodynamic analysis of the proton-induced multifragmentation phenomena the most appropriate decay channel corresponding to the realistic phase trajectory is chosen. Macroscopic analysis of the suggested decay channel is done in order to check the possibility of the mechanical breakdown of the heated system. Based on a simple thermodynamic model preliminary quantitative calculations of corresponding macroscopic parameters (energy, pressure) are done and therefore the model verification on macroscopic level is held. It is shown that on macroscopic level the chosen decay channel through the mechanical breakdown meets the necessary conditions for describing the proton-induced multifragmentation phenomena

  12. Natural phenomena risk assessment at Rocky Flats Plant

    International Nuclear Information System (INIS)

    Foppe, T.L.

    1985-01-01

    A realistic approach is currently being used at the Rocky Flats Plant to assess the risks of natural phenomena events. The methodology addresses frequency of occurrence estimates, damage stress on the facility and vital equipment, material-at-risk, release fractions and source terms, leakpath, dispersion and dosimetric models, risk curves, and an uncertainty analysis. 28 references, 1 figure

  13. Coupled electric and transport phenomena in porous media

    NARCIS (Netherlands)

    Li, Shuai

    2014-01-01

    The coupled electrical and transport properties of clay-containing porous media are the topics of interest in this study. Both experimental and numerical (pore network modeling) techniques are employed to gain insight into the macro-scale interaction between electrical and solute transport phenomena

  14. The JET ECE heterodyne radiometer and investigations of fast phenomena

    International Nuclear Information System (INIS)

    Bartlett, D.V.; Porte, L.

    1993-01-01

    In this paper, the design and performance characteristics of the JET heterodyne radiometer are reviewed, and some novel aspects of the instrument are described. Areas where the radiometer could benefit from further improvement are highlighted, and those improvements currently in progress are discussed. Some measurements which demonstrate the radiometer's power as a diagnostic of fast phenomena are presented. (orig.)

  15. Progress in the theory of magnetic reconnection phenomena

    International Nuclear Information System (INIS)

    Ottaviani, M.; Arcis, N.; Maget, P.; Zwingmann, W.; Grasso, D.; Militello, F.; Porcelli, F.

    2004-01-01

    Recent theoretical work on magnetic reconnection in hot plasma confinement devices is reviewed. The presentation highlights the common aspects of reconnection phenomena, and current research trends are emphasised. Progress in understanding the dynamics of slowly evolving modes of the tearing family, based on advanced analytic techniques and numerical simulation, as well as of faster modes that lead to internal disruptions, is reported. (authors)

  16. Judgments of widely held beliefs about psychological phenomena ...

    African Journals Online (AJOL)

    Lay understandings of human cognition, affect, and behaviour often diverge from the findings of scientific investigations. The present study examined South African fourth year psychology students' judgments about the factual correctness of statements of psychological phenomena that have been demonstrated to be ...

  17. Explosive phenomena in heavily irradiated NaCl

    NARCIS (Netherlands)

    denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

    1997-01-01

    In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

  18. High Energy Phenomena in Eta Carinae Roberto F. Viotti , Lucio ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    High Energy Phenomena in Eta Carinae ... Colliding winds model—non-thermal emission—stars: η ... very massive wind. Its unseen compan- ion should be a less evolved early-type star. It was found that the two last spectroscopic minima of June 1992 and December 1997 coincided with two X-ray eclipses detected.

  19. The challenge of quantum computer simulations of physical phenomena

    International Nuclear Information System (INIS)

    Ortiz, G.; Knill, E.; Gubernatis, J.E.

    2002-01-01

    The goal of physics simulation using controllable quantum systems ('physics imitation') is to exploit quantum laws to advantage, and thus accomplish efficient simulation of physical phenomena. In this Note, we discuss the fundamental concepts behind this paradigm of information processing, such as the connection between models of computation and physical systems. The experimental simulation of a toy quantum many-body problem is described

  20. The sun as a star: Solar phenomena and stellar applications

    International Nuclear Information System (INIS)

    Noyes, R.W.

    1981-01-01

    Our Sun is a run-of-the-mill star, having no obvious extremes of stellar properties. For this reason it is perhaps more, rather than less, interesting as an astrophysical object, for its sameness to other stars suggests that in studying the Sun, we are studying at close hand common, rather than unusual stellar phenomena. Conversely, comparative study of the Sun and other solar-type stars is an invaluable tool for solar physics, for two reasons: First, it allows us to explore how solar properties and phenomena depend on parameters we cannot vary on the Sun - most fundamentally, rotation rate and mass. Second, study of solar-like stars of different ages allows us to see how stellar and solar phenomena depend on age; study of other stars may be one of the best ways to infer the earlier history of the Sun, as well as its future history. In this review we shall concentrate on phenomena common to the Sun and solar-type (main sequence) stars with different fundamental properties such as mass, age, and rotation. (orig.)

  1. Primary Issues of Mixed Convection Heat Transfer Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Myeong-Seon; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    The computer code analyzing the system operating and transient behavior must distinguish flow conditions involved with convective heat transfer flow regimes. And the proper correlations must be supplied to those flow regimes. However the existing safety analysis codes are focused on the Light Water Reactor and they are skeptical to be applied to the GCRs (Gas Cooled Reactors). One of the technical issues raise by the development of the VHTR is the mixed convection, which occur when the driving forces of both forced and natural convection are of comparable magnitudes. It can be encountered as in channel of the stacked with fuel elements and a decay heat removal system and in VHTR. The mixed convection is not intermediate phenomena with natural convection and forced convection but independent complicated phenomena. Therefore, many researchers have been studied and some primary issues were propounded for phenomena mixed convection. This paper is to discuss some problems identified through reviewing the papers for mixed convection phenomena. And primary issues of mixed convection heat transfer were proposed respect to thermal hydraulic problems for VHTR. The VHTR thermal hydraulic study requires an indepth study of the mixed convection phenomena. In this study we reviewed the classical flow regime map of Metais and Eckert and derived further issues to be considered. The following issues were raised: (1) Buoyancy aided an opposed flows were not differentiated and plotted in a map. (2) Experimental results for UWT and UHF condition were also plotted in the same map without differentiation. (3) The buoyancy coefficient was not generalized for correlating with buoyancy coefficient. (4) The phenomenon analysis for laminarization and returbulization as buoyancy effects in turbulent mixed convection was not established. (5) The defining to transition in mixed convection regime was difficult.

  2. Seasonality of alcohol-related phenomena in Estonia

    Science.gov (United States)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  3. Solid state physics: magnetic phenomena. Final report, 1961--1975

    International Nuclear Information System (INIS)

    Bowers, R.; Silsbee, R.H.

    1976-01-01

    Research activities centered at Cornell University in: (1) electron spin resonance and (2) the electronic transport properties of metals, are described. A list of 150 publications and technical reports published by this group since 1958 is included

  4. Atlas of neutron resonances

    CERN Document Server

    Mughabghab, Said

    2018-01-01

    Atlas of Neutron Resonances: Resonance Properties and Thermal Cross Sections Z= 1-60, Sixth Edition, contains an extensive list of detailed individual neutron resonance parameters for Z=1-60, as well as thermal cross sections, capture resonance integrals, average resonance parameters and a short survey of the physics of thermal and resonance neutrons. The long introduction contains: nuclear physics formulas aimed at neutron physicists; topics of special interest such as valence neutron capture, nuclear level density parameters, and s-, p-, and d-wave neutron strength functions; and various comparisons of measured quantities with the predictions of nuclear models, such as the optical model. As in the last edition, additional features have been added to appeal to a wider spectrum of users. These include: spin-dependent scattering lengths that are of interest to solid-state physicists, nuclear physicists and neutron evaluators; calculated and measured Maxwellian average 5-keV and 30-keV capture cross sections o...

  5. Magnetic resonance imaging apparatus

    International Nuclear Information System (INIS)

    Ehnholm, G.J.

    1991-01-01

    This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

  6. Electron paramagnetic resonance

    CERN Document Server

    Al'tshuler, S A

    2013-01-01

    Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

  7. Ramifide resonators for cyclotrons

    International Nuclear Information System (INIS)

    Smirnov, Yu.V.

    2000-01-01

    The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru

  8. Phenomena-based Process Synthesis and Design to achieve Process Intensification

    DEFF Research Database (Denmark)

    Lutze, Philip; Babi, Deenesh Kavi; Woodley, John

    2012-01-01

    at the lowest level of aggregation: phenomena. Therefore, in this paper, a phenomena-based synthesis/design methodology is presented. Using this methodology, a systematic identification of necessary and desirable (integrated) phenomena as well as generation and screening of phenomena-based flowsheet options...

  9. Loss experience from natural phenomena hazards in the Department of Energy (50 years of natural phenomena hazard losses)

    International Nuclear Information System (INIS)

    Hill, J.R.

    1993-01-01

    This paper presents a historical prespective on losses due to natural hazard incidents (1943-1993) at Department of Energy (DOE) and predecessor agencies including the Atomic Energy Commission (AEC) and the Energy Research and Development Agency (ERDA). This paper also demonstrates how an existing DOE resource can be used to gain valuable insight into injury or property damage incidents. That resource is the Computerized Accident/Incident Reporting System (CAIRS) module of DOE's Safety Performance Measurement System. CAIRS data selected the 1981-1991 DOE injury/illness reports, from all the accident reports of the AEC that cited a natural phenomena hazard as either the direct or indirect cause of the injury/property damage. Specifically, injury or property damage reports were selected for analysis if they had a causal factor link to severe weather or natural phenomena hazard categories. Natural phenomena hazard categories are injury/property damage caused by hurricane/tornado, earthquake, lightning, or flood. Severe weather categories are injury/property damage associated with other than normal weather conditions. The lessons learned, as a result of reviewing case histories, are presented, as are suggestions on how to reduce the likelihood of future injuries/property damage as a result of similar events. A significant finding, is that most injuries and property damage were the result of an indirect causal link to a natural phenomena hazard and thus, may be more preventable than previously thought possible. The primary message, however, is that CAIRS and other incident data bases are valuable resources and should be considered for use by those interested in identifying new ways of protecting the health and safety of the worker and for reducing building losses due to the effects of natural phenomena hazards

  10. Doppleron resonances in the diffraction of atoms by an evanescent field

    International Nuclear Information System (INIS)

    Murphy, J.E.; Hollenberg, L.C.L.; Smith, A.E.

    1994-01-01

    The diffracted intensities of sodium atoms by a standing evanescent light wave near the three doppleron resonance are calculated using a multi-slice technique. This calculation predicts a sharp dip in the reflected intensity of the specular beam for a detuning slightly below resonance. Such phenomena has been observed experimentally and can be understood using the dressed state picture. 4 refs., 2 tabs., 3 figs

  11. R-ES-ONAN--CE

    Indian Academy of Sciences (India)

    Mathematics, Engineering: Turbulence, stability of fluid flows, two phase flow, thermal science, biochemical engineering, polymer engineering, chemical reactor analysis, transport phenomena, interfacial phenomena, process metallurgy, physi- cal metallurgy, ceramics, composite materials and computer science or ...

  12. Resonance modulation, annihilation and generation of anti-resonance and anti-phasonance in 3D neuronal systems: interplay of resonant and amplifying currents with slow dynamics.

    Science.gov (United States)

    Rotstein, Horacio G

    2017-08-01

    Subthreshold (membrane potential) resonance and phasonance (preferred amplitude and zero-phase responses to oscillatory inputs) in single neurons arise from the interaction between positive and negative feedback effects provided by relatively fast amplifying currents and slower resonant currents. In 2D neuronal systems, amplifying currents are required to be slave to voltage (instantaneously fast) for these phenomena to occur. In higher dimensional systems, additional currents operating at various effective time scales may modulate and annihilate existing resonances and generate antiresonance (minimum amplitude response) and antiphasonance (zero-phase response with phase monotonic properties opposite to phasonance). We use mathematical modeling, numerical simulations and dynamical systems tools to investigate the mechanisms underlying these phenomena in 3D linear models, which are obtained as the linearization of biophysical (conductance-based) models. We characterize the parameter regimes for which the system exhibits the various types of behavior mentioned above in the rather general case in which the underlying 2D system exhibits resonance. We consider two cases: (i) the interplay of two resonant gating variables, and (ii) the interplay of one resonant and one amplifying gating variables. Increasing levels of an amplifying current cause (i) a response amplification if the amplifying current is faster than the resonant current, (ii) resonance and phasonance attenuation and annihilation if the amplifying and resonant currents have identical dynamics, and (iii) antiresonance and antiphasonance if the amplifying current is slower than the resonant current. We investigate the underlying mechanisms by extending the envelope-plane diagram approach developed in previous work (for 2D systems) to three dimensions to include the additional gating variable, and constructing the corresponding envelope curves in these envelope-space diagrams. We find that antiresonance and

  13. SUPERCOMPUTER SIMULATION OF CRITICAL PHENOMENA IN COMPLEX SOCIAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Petrus M.A. Sloot

    2014-09-01

    Full Text Available The paper describes a problem of computer simulation of critical phenomena in complex social systems on a petascale computing systems in frames of complex networks approach. The three-layer system of nested models of complex networks is proposed including aggregated analytical model to identify critical phenomena, detailed model of individualized network dynamics and model to adjust a topological structure of a complex network. The scalable parallel algorithm covering all layers of complex networks simulation is proposed. Performance of the algorithm is studied on different supercomputing systems. The issues of software and information infrastructure of complex networks simulation are discussed including organization of distributed calculations, crawling the data in social networks and results visualization. The applications of developed methods and technologies are considered including simulation of criminal networks disruption, fast rumors spreading in social networks, evolution of financial networks and epidemics spreading.

  14. Theoretical and experimental notes on noise phenomena of KUR

    International Nuclear Information System (INIS)

    Kishida, Kuniharu

    1980-01-01

    The classification of global or local noise is important in reactor noise analysis. The term of ''global'' or ''local'' corresponds to that of ''system size'' or ''cell size'' in statistical physics. On the other hand, point model or phase space description is used in time series analysis. If a time series model describing spatial behavior is established, it will serve to reactor diagnosis. The noise phenomena of KUR are discussed from these points of view. In other words, from experimental results, the point reactor picture is reasonable to neutronic aspect but quantitative problem remains in coolant temperature fluctuations. By taking into account a diffusion type model, the spatial dependence is discussed for the problem remaining in coolant temperature fluctuations. It is pointed out that the time-space picture is a crucial idea of reactor noise phenomena. (author)

  15. Two-Phase Phenomena In Wet Flue Gas Desulfurization Process

    International Nuclear Information System (INIS)

    Minzer, U.; Moses, E.J.; Toren, M.; Blumenfeld, Y.

    1998-01-01

    In order to reduce sulfur oxides discharge, Israel Electric Corporation (IEC) is building a wet Flue Gas Desulfurization (FGD) facility at Rutenberg B power station. The primary objective of IEC is to minimize the occurrence of stack liquid discharge and avoid the discharge of large droplets, in order to prevent acid rain around the stack. Liquid discharge from the stack is the integrated outcome of two-phase processes, which are discussed in this work. In order to estimate droplets discharge the present investigation employs analytical models, empirical tests, and numerical calculations of two-phase phenomena. The two-phase phenomena are coupled and therefore cannot be investigated separately. The present work concerns the application of Computational Fluid Dynamic (CFD) as an engineering complementary tool in the IEC investigation

  16. Introduction to symmetry-breaking phenomena in physics

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2001-01-01

    The notion of broken symmetries started slowly to emerge in the 19th century. The early studies of Pasteur on the parity asymmetry of life, the studies of Curie on piezoelectricity and on the symmetries of effects versus the symmetry of causes ( which clearly excluded spontaneous symmetry breaking), are important historical landmarks. However the possibility of spontaneous symmetry breaking within the usual principles of statistical mechanics, waited for the work of Peierls and Onsager. The whole theory of phase transitions and critical phenomena, as well as the construction of field theoretic models as long distance limit of yet unknown physics, relies nowadays on the concept of criticality associated to spontaneous symmetry breaking. The phenomena of Goldstone bosons, of Meissner-Higgs effects, are central to the theory of condensed matter as well as to particle physics. In cosmology as well, the various inflationary scenarios begin similarly with this same concept. The three lectures will provide a simple ...

  17. Computational transport phenomena of fluid-particle systems

    CERN Document Server

    Arastoopour, Hamid; Abbasi, Emad

    2017-01-01

    This book concerns the most up-to-date advances in computational transport phenomena (CTP), an emerging tool for the design of gas-solid processes such as fluidized bed systems. The authors examine recent work in kinetic theory and CTP and illustrate gas-solid processes’ many applications in the energy, chemical, pharmaceutical, and food industries. They also discuss the kinetic theory approach in developing constitutive equations for gas-solid flow systems and how it has advanced over the last decade as well as the possibility of obtaining innovative designs for multiphase reactors, such as those needed to capture CO2 from flue gases. Suitable as a concise reference and a textbook supplement for graduate courses, Computational Transport Phenomena of Gas-Solid Systems is ideal for practitioners in industries involved with the design and operation of processes based on fluid/particle mixtures, such as the energy, chemicals, pharmaceuticals, and food processing. Explains how to couple the population balance e...

  18. Anomalous radon emanation linked to preseismic electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    Y. Omori

    2007-10-01

    Full Text Available Anomalous emanation of radon (222Rn was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances. Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

  19. Preface to special issue: Layered Phenomena in the Mesopause Region

    Science.gov (United States)

    Chu, Xinzhao; Marsh, Daniel R.

    2017-09-01

    Historically, the Layered Phenomena in the Mesopause Region (LPMR) workshops have focused on studies of mesospheric clouds and their related science, including spectacular noctilucent clouds (NLCs), polar mesospheric clouds (PMCs), and polar mesospheric summer echoes (PMSEs). This is because, in the pre-technology era, these high-altitude ( 85 km) clouds revealed the existence of substance above the 'normal atmosphere' - our near-space environment is not empty! The occurrence and nature of these clouds have commanded the attention of atmospheric and space scientists for generations. Modern technologies developed in the last 50 years have enabled scientists to significantly advance our understanding of these layered phenomena. Satellite observations expanded these studies to global scales, while lidar and radar observations from the ground enabled fine-scale studies. The launch of the Aeronomy of Ice in the Mesosphere (AIM) satellite in 2007 brought mesospheric cloud research to a more mature level.

  20. An assessment of Gallistel's (2012) rationalistic account of extinction phenomena.

    Science.gov (United States)

    Miller, Ralph R

    2012-05-01

    Gallistel (2012) asserts that animals use rationalistic reasoning (i.e., information theory and Bayesian inference) to make decisions that underlie select extinction phenomena. Rational processes are presumed to lead to evolutionarily optimal behavior. Thus, Gallistel's model is a type of optimality theory. But optimality theory is only a theory, a theory about an ideal organism, and its predictions frequently deviate appreciably from observed behavior of animals in the laboratory and the real world. That is, behavior of animals is often far from optimal, as is evident in many behavioral phenomena. Hence, appeals to optimality theory to explain, rather than illuminate, actual behavior are misguided. Copyright © 2012 Elsevier B.V. All rights reserved.