WorldWideScience

Sample records for nuclear collective motion

  1. A microscopic theory of the nuclear collective motion

    International Nuclear Information System (INIS)

    Baranger, M.

    1975-01-01

    A microscopic theory of the nuclear collective model is reviewed, discussions being concentrated, mainly, on the shape motion. An adiabatic time dependent Hartree-Fock method is used. Kinetic energy using the cranking model is obtained. The generator coordinate method is discussed [pt

  2. Microscopic boson approach to nuclear collective motion

    International Nuclear Information System (INIS)

    Kuchta, R.

    1989-01-01

    A quantum mechanical approach to the maximally decoupled nuclear collective motion is proposed. The essential idea is to transcribe the original shell-model Hamiltonian in terms of boson operators, then to isolate the collective one-boson eigenstates of the mapped Hamiltonian and to perform a canonical transformation which eliminates (up to the two-body terms) the coupling between the collective and noncollective bosons. Unphysical states arising due to the violtion of the Pauli principle in the boson space are identified and removed within a suitable approximation. The method is applied to study the low-lying collective states of nuclei which are successfully described by the exactly solvable multilevel pairing Hamiltonian (Sn, Ni, Pb). 75 refs.; 8 figs

  3. Group theoretic approaches to nuclear and hadronic collective motion

    International Nuclear Information System (INIS)

    Biedenharn, L.C.

    1982-01-01

    Three approaches to nuclear and hadronic collective motion are reviewed, compared and contrasted: the standard symmetry approach as typified by the Interacting Boson Model, the kinematic symmetry group approach of Gell-Mann and Tomonaga, and the recent direct construction by Buck. 50 references

  4. Group theoretic approaches to nuclear and hadronic collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Biedenharn, L.C.

    1982-01-01

    Three approaches to nuclear and hadronic collective motion are reviewed, compared and contrasted: the standard symmetry approach as typified by the Interacting Boson Model, the kinematic symmetry group approach of Gell-Mann and Tomonaga, and the recent direct construction by Buck. 50 references.

  5. Description of nuclear collective motion by Wigner function moments

    International Nuclear Information System (INIS)

    Balbutsev, E.B.

    1996-01-01

    The method is presented in which the collective motion is described by the dynamic equations for the nuclear integral characteristics. The 'macroscopic' dynamics is formulated starting from the equations of the microscopic theory. This is done by taking the phase space moments of the Wigner function equation. The theory is applied to the description of collective excitations with multipolarities up to λ=5. (author)

  6. On the role of memory effects for dissipation and diffusion in slow collective nuclear motion

    International Nuclear Information System (INIS)

    Cassing, W.; Noerenberg, W.

    1983-01-01

    The energy dissipation in slow collective nuclear motion is viewed as a combined effect of a diabatic production of particle-hole excitations, leading to a conservative storage of collective energy, and a subsequent equilibration due to residual two-body collisions. The effective equation of motion for the collective degree of freedom turns out to be nonlocal in time due to the large mean free path of the nucleons and allows for a simultaneous description of two different attitudes of nuclear matter. The elastic response of heavy nuclei for ''fast'' collective motion switches over to pure friction for very slow collective motion. The time development of the fluctuations in the velocities may show oscillations for times comparable to the local equilibration time and hence, is qualitatively different from the classical limit. A first application of the diabatic dynamical approach is made for the quadrupole motion within a diabatic deformed harmonic oscillator basis. (orig.)

  7. Dissipation and nuclear collective motion

    International Nuclear Information System (INIS)

    Hofmann, Helmut; Jensen, A.S.; Ngo, Christian; Siemens, P.J.; California Univ., Berkeley

    1979-01-01

    This contribution is intended to give a brief summary of a forthcoming paper which shall review extensively the linear response theory for dissipation and statistical fluctuations as well as its application to heavy-ion collisions. It shall contain new results on the following subjects: numerical computations of response functions and transport coefficients; dissipation in a self-consistent treatment of harmonic vibrations; introduction of collective variables within a quantum theory. The method used consists of an extended version of the Bohm and Pines treatment of the electron gas. It allows to deduce a quantum Hamiltonian for the collective and intrinsic motion including coupling terms; discussion and solution of a quantal Master equation for non-linear collective motion. Additionally, a somewhat elaborate discussion of the problems of irreversibility is given, especially in connection to a treatment within the moving basis

  8. U(6)-phonon model of nuclear collective motion

    International Nuclear Information System (INIS)

    Ganev, H.G.

    2015-01-01

    The U(6)-phonon model of nuclear collective motion with the semi-direct product structure [HW(21)]U(6) is obtained as a hydrodynamic (macroscopic) limit of the fully microscopic proton–neutron symplectic model (PNSM) with Sp(12, R) dynamical group. The phonon structure of the [HW(21)]U(6) model enables it to simultaneously include the giant monopole and quadrupole, as well as dipole resonances and their coupling to the low-lying collective states. The U(6) intrinsic structure of the [HW(21)]U(6) model, from the other side, gives a framework for the simultaneous shell-model interpretation of the ground state band and the other excited low-lying collective bands. It follows then that the states of the whole nuclear Hilbert space which can be put into one-to-one correspondence with those of a 21-dimensional oscillator with an intrinsic (base) U(6) structure. The latter can be determined in such a way that it is compatible with the proton–neutron structure of the nucleus. The macroscopic limit of the Sp(12, R) algebra, therefore, provides a rigorous mechanism for implementing the unified model ideas of coupling the valence particles to the core collective degrees of freedom within a fully microscopic framework without introducing redundant variables or violating the Pauli principle. (author)

  9. Collective nuclear dynamics. Abstracts

    International Nuclear Information System (INIS)

    Abrosimov, V.I.; Kolomietz, V.M.

    1994-01-01

    The fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects: liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities

  10. Collective nuclear dynamics. Proceedings

    International Nuclear Information System (INIS)

    Ivanyuk, F.A.

    1994-01-01

    The Fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects:liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities

  11. Collective nuclear dynamics. Proceedings.

    Energy Technology Data Exchange (ETDEWEB)

    Ivanyuk, F A [eds.

    1994-12-31

    The Fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects:liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities.

  12. Self-consistent treatment of nuclear collective motion with an application to the giant-dipole resonance

    International Nuclear Information System (INIS)

    Liran, S.; Technion-Israel Inst. of Tech., Haifa. Dept. of Physics)

    1977-01-01

    This paper extends the recent theory of Liran, Scheefer, Scheid and Greiner on non-adiabatic cranking and nuclear collective motion. In the present work we show the self-consistency conditions for the collective motion, which are indicated by appropriate time-dependent Lagrange multipliers, can be treated explicitly. The energy conservation and the self-consistency condition in the case of one collective degree of freedom are expressed in differential form. This leads to a set of coupled differential equations in time for the many-body wave function, for the collective variable and for the Lagrange multiplier. An iteration procedure similar to that of the previous work is also presented. As an illustrative example, we investigate Brink's single-particle description of the giant-dipole resonance. In this case, the important role played by non-adiabaticity and self-consistency in determining the collective motion is demonstrated and discussed. We also consider the fact that in this example of a fast collective motion, the adiabatic cranking model of Inglis gives the correct mass parameter. (orig.) [de

  13. New trends in nuclear collective dynamics

    International Nuclear Information System (INIS)

    Abe, Yasuhisa; Horiuchi, Hisashi; Matsuyanagi, Kenichi

    1992-01-01

    New Trends in Nuclear Collective Dynamics comprises reviews by well-known researchers from international centers of nuclear physics. This overview of recent advances concentrates on - order amd chaos in finite quantum systems - dissipation in heavy-ion collions - collective motion in warm nuclei - time-dependent mean-field theory with collision terms - nuclear fission and multi-dimensional tunneling - large scale collective motion see hints under the relevent topics. (orig.) With 90 figs

  14. Descriptions of the equilibration process of the intrinsic degrees of freedom and dissipative process of the nuclear collective motion

    International Nuclear Information System (INIS)

    Feng Renfa; Zhang Jingshang; Ma Zhongyu; Wu Xizhen; Zhuo Yizhong

    1984-01-01

    In this paper the Hamiltonian model is used for studying the nuclear dynamics by taking both the one-body and two-body interaction mechanisms into account. On the basis of the Von Neuman equation the coupling between the collective motion and the single particle degrees of freedom is discussed. Thus, the equations obtained are physically transparent and easy for numerical computations. They may be useful for describing the dissipative process of the nuclear collective motion as well as the equilibration process of the intrinsic degrees of freedom. (Author)

  15. Nuclear collective motion within the O(N-1) invariant dynamics

    International Nuclear Information System (INIS)

    Cerkaski, M.; Mikhailov, I.N.

    1990-08-01

    Assuming the O(N-1) symmetry for the interaction term in the N-body Hamiltonian we find a closed subsystem of equations describing the collective motion in a classical way. Within the model, the nucleons move along trajectories determined by a one-body time-dependent harmonic potential depending on the collective variables. The relation of the equations for the collective motion to the system of equations found elsewhere for the second order moments of the Wigner distribution function is discussed. The problem of finding stationary solutions to the collective equations of motion leads to the cranking model with the selfconsistency relations depending on the O(N-1) scalar part of the potential. 52 refs. (author)

  16. Theoretical research in nuclear collective motion. Progress report

    International Nuclear Information System (INIS)

    1984-01-01

    Progress is summarized on the following research projects: generalized density matrix method, large amplitude collective motion, boson mappings for the Interacting Boson Model, and semi-classical method for testing IBM hypothesis

  17. Dynamic response function and large-amplitude dissipative collective motion

    International Nuclear Information System (INIS)

    Wu Xizhen; Zhuo Yizhong; Li Zhuxia; Sakata, Fumihiko.

    1993-05-01

    Aiming at exploring microscopic dynamics responsible for the dissipative large-amplitude collective motion, the dynamic response and correlation functions are introduced within the general theory of nuclear coupled-master equations. The theory is based on the microscopic theory of nuclear collective dynamics which has been developed within the time-dependent Hartree-Fock (TDHF) theory for disclosing complex structure of the TDHF-manifold. A systematic numerical method for calculating the dynamic response and correlation functions is proposed. By performing numerical calculation for a simple model Hamiltonian, it is pointed out that the dynamic response function gives an important information in understanding the large-amplitude dissipative collective motion which is described by an ensemble of trajectories within the TDHF-manifold. (author)

  18. Selfconsistent diabatic approach to dissipative collective nuclear motion

    International Nuclear Information System (INIS)

    Niita, K.; Wang, S.J.; Noerenberg, W.; Technische Hochschule Darmstadt

    1986-09-01

    Within a selfconsistent description for the one- and two-body density matrices collective variables are introduced via scaling diabatic states. Equations of collective motion coupled to a collision integral for the single-particle occupation probabilities are derived from the randomness of the two-body interaction matrix elements and from an additional time smoothing procedure. For a linear approximation to the time-dependence of the single-particle energies the collision term conserves energy all by itself, i.e. the time-smoothed time derivative of the correlation energy vanishes. (orig.)

  19. Microscopic theory of nuclear collective dynamics

    International Nuclear Information System (INIS)

    Sakata, Fumihiko; Marumori, Toshio; Hashimoto, Yukio; Tsukuma, Hidehiko; Yamamoto, Yoshifumi; Iwasawa, Kazuo.

    1990-10-01

    A recent development of the INS-TSUKUBA joint research project on large-amplitude collective motion is summarized by putting special emphasis on an inter-relationship between quantum chaos and nuclear spectroscopy. Aiming at introducing various concepts used in this lecture, we start with recapitulating the semi-classical theory of nuclear collective dynamics formulated within the time-dependent Hartree-Fock (TDHF) theory. The central part of the semi-classical theory is provided by the self-consistent collective coordinate (SCC) method which has been developed to properly take account of the non-linear dynamics specific for the finite many-body quantum system. A decisive role of the level crossing dynamics on the order-to-chaos transition of collective motion is discussed in detail. Extending the basic idea of the semi-classical theory, we discuss a full quantum theory of nuclear collective dynamics which allows us to properly define a concept of the quantum integrability as well as the quantum chaoticity for each eigenfunction. The lecture is arranged so as to clearly show the similar structure between the semi-classical and quantum theories of nuclear collective dynamics. Using numerical calculations, we illustrate what the quantum chaos for each eigenfunction means and relate it to the usual definition of quantum chaos for nearest neighbor level spacing statistics based on the random matrix theory. (author)

  20. Nuclear magnetic resonance method and apparatus for reducing motion artifacts

    International Nuclear Information System (INIS)

    Bailes, D.R.

    1988-01-01

    A nuclear magnetic resonance apparatus for imaging a region of a body in which part of the region is moving with a motion such that its displacement with respect to time is a nonmonotonic function during a time period over which a plurality of NMR data signals, which together define an image, are collected. The apparatus is described comprising: excitation means arranged to excite nuclear magnetic spins preferentially in the region; encoding means arranged to encode the magnetic spins; data collection means arranged to collect data signals representative of encoded magnetic spins; display means responsive to collected data signals to display an image of the region; measuring means arranged to produce an output indicative of the displacement of the moving part of the region; and control means for controlling the encoding means during the time period in dependence on the output of the measuring means so that data signals collected during the time period are collected in an order dependent on the motion such that motion artifacts are reduced

  1. A few methods for the theory of collective motions and collisions

    International Nuclear Information System (INIS)

    Giraud, B.G.

    1984-01-01

    In this series of lectures the time-dependent Hartree-Fock theory of nuclear motions and collisions are treated for collective motion only. For the theory of collisions a representation, the boosted shell model, is proposed in which matrix elements of the T-matrix are easier to evaluate via a variational principle

  2. Whole study of nuclear matter collective motion in central collisions of heavy ions of the FOPI detector

    International Nuclear Information System (INIS)

    Bendarag, A.

    1999-01-01

    In this work we study the collective phenomena in the central collisions of heavy ions for the Au + Au, Xe + CsI and Ni + Ni systems at incident energies from 150 to 400 MeV/nucleon with the data of the FOPI detector. In order to describe completely the flow of the nuclear matter, we fit the double differential momentum distributions with two-dimensional Gaussian. We study the characteristic parameters of the collective flow (flow range, aspect ratios, flow parameter) versus the charge and the mass of the fragments as well as the incident energy and the centrality of the collisions. The transverse energy is used for selecting the central collisions. The method of the Gaussian fits requires also to reconstruct the reaction plane of the event. Then we correct the parameters for the finite number of particles effects and account for the influence of the acceptance of the detector. We confirm the importance of the thermal motion for the light charge or mass fragments and, conversely, the predominance of the collective motion for the heavy fragments. A common flow angle for all the types of particles is highlighted for the first time, demonstrating the power of the method of the Gaussian fits; The evolution of the other parameters confirms the observations done with other methods of flow analysis. These results should contribute to put constraints on the collision models and to enlarge our knowledge of the properties of the nuclear matter. (author)

  3. Instability in nuclear dynamics: loss of collectivity and multifragmentation

    International Nuclear Information System (INIS)

    Colonna, M.; Di Toro, M.; Guarnera, A.; Latora, V.; Smerzi, A.

    1995-01-01

    Two limiting cases of nuclear dynamics are analysed: the disappearing of giant collective motions in hot nuclei and the nuclear disassembly in violent heavy ion collisions. For collective vibration build on excited states we get a dramatic increase of the widths of hot Giant Dipole Resonances (GDR). As a consequence of the competition with particle evaporation we get a sharp quenching of giant photon emission. Pre-equilibrium effects on the GDR formation are also accounted for. At high temperature and low density the collective motions can become unstable leading to multifragmentation events in heavy ion collisions. We present a general procedure to identify instability regions and to get informations on the instability point. Some hints towards fully dynamical picture of multi-fragmentation processes are finally suggested. (author)

  4. The time dependent Hartree-Fock-theory for collective nuclear motions

    International Nuclear Information System (INIS)

    Goeke, K.

    1976-11-01

    The time-dependent Hartree-Fock theory (TDHF) approximately solves the Schroedinger equation by a variational method in the space of the time-dependent Slater determinants. As the TDHF wave function, similar to the exact solution has the property of being determined completely for all times by the nucleon-nucleon interaction and by assuming initial conditions. TDHF is expected to describe collective motion of nuclei with large amplitudes, too. The subject of this paper is to formulate the TDHF theory and its adiabatic limiting case (ATDHF) suited for setting up a collective Schroedinger equation, to investigate the relations with other theories, and to show the applicability for solving practical problems. (orig./WL) [de

  5. Non-unitary boson mapping and its application to nuclear collective motions

    International Nuclear Information System (INIS)

    Takada, Kenjiro

    2001-01-01

    First, the general theory of boson mapping for even-number many-fermion systems is surveyed. In order to overcome the confusion concerning the so-called unphysical or spurious states in the boson mapping, the correct concept of the unphysical states is precisely given in a clear-cut way. Next, a method to apply the boson mapping to a truncated many-fermion Hilbert space consisting of collective phonons is proposed, by putting special emphasis on the Dyson-type non-unitary boson mapping. On the basis of this method, it becomes possible for the first time to apply the Dyson-type boson mapping to analyses of collective motions in realistic nuclei. This method is also extended to be applicable to odd-number-fermion systems. As known well, the Dyson-type boson mapping is a non-unitary transformation and it gives a non-Hermitian boson Hamiltonian. It is not easy (but not impossible) to solve the eigenstates of the non-Hermitian Hamiltonian. A Hermitian treatment of this non-Hermitian eigenvalue problem is discussed and it is shown that this treatment is a very good approximation. using this Hermitian treatment, we can obtain the normal-ordered Holstein-Primakoff-type boson expansion in the multi-collective-phonon subspace. Thereby the convergence of the boson expansion can be tested. Some examples of application of the Dyson-type non-unitary boson mapping to simplified models and realistic nuclei are also shown, and we can see that it is quite useful for analysis of the collective motions in realistic nuclei. In contrast to the above-mentioned ordinary type of boson mapping, which may be called a a 'static' boson mapping, the Dyson-type non-unitary self-consistent-collective-coordinate method is discussed. The latter is, so to speak, a 'dynamical' boson mapping, which is a dynamical extension of the ordinary boson mapping to be capable to include the coupling effects from the non-collective degrees of freedom self-consistently.Thus all of the Dyson-type non-unitary boson

  6. A quantal transport theory for nuclear collective motion: the merits of a locally harmonic approximation

    International Nuclear Information System (INIS)

    Hofmann, H.

    1997-01-01

    A transport theory is developed for collective motion of systems such as an atomic nucleus, which may be considered as a typical representative of a self-bound micro-system. Albeit for pragmatic reasons, collective variables are introduced as shape parameters, self-consistency with respect to the nucleonic degrees of freedom has been implemented at various important stages. This feature leads to subsidiary conditions which are obeyed locally for both the average motion as well as for the quantized Hamiltonian constructed through a Bohm-Pines procedure. Furthermore, self-consistency governs the definition of the transport coefficients appearing in the equations for collective motion. The latter is associated to the time evolution of the density in collective phase space, for which the concept of the Wigner function is employed. Global motion is described by propagating the system in successive time laps which are macroscopically small, but microscopically large. This enables one to exploit linearization procedures and to take advantage of the benefits of linear response theory. A microscopic damping mechanism is introduced by dressing the energies of the independent particle model by complex self-energies, the parameters of which are determined from optical model considerations. Numerical evaluations of transport coefficients are described and tested for the case of fission in the light of recent experimental findings. The theory allows one to extend both Kramers' picture of this process as well as his equation for the density distribution into the quantum regime. (orig.)

  7. Collective motion in behaviorally heterogeneous systems

    OpenAIRE

    Copenhagen, Katherine

    2017-01-01

    Collective motion is a widespread phenomenon in nature where individuals actively propel themselves, gather together and move as a group. Some examples of collective motion are bird flocks, fish schools, bacteria swarms, cell clusters, and crowds of people. Many models seek to understand the effects of activity in collective systems including things such as environmental disorder, density, and interaction details primarily at infinite size limits and with uniform populations. In this disserta...

  8. Nuclear friction and chaotic motion

    International Nuclear Information System (INIS)

    Srokowski, T.; Szczurek, A.; Drozdz, S.

    1990-01-01

    The concept of nuclear friction is considered from the point of view of regular versus chaotic motion in an atomic nucleus. Using a realistic nuclear Hamiltonian it is explicitly shown that the frictional description of the gross features of nuclear collisions is adequate if the system behaves chaotically. Because of the core in the Hamiltonian, the three-body nuclear system already reveals a structure of the phase space rich enough for this concept to be applicable

  9. Large amplitude nuclear collective motion and the quantized ATDHF theory

    International Nuclear Information System (INIS)

    Provoost, D.

    1986-03-01

    It is the aim of the present work to present some numerical results obtained within the ATDHF formalism. Both approaches have been considered, the construction of the collective Hamiltonian as well as the solution of the Griffin-Hill-Wheeler equation, both using the ATDHF collective path. We show that a fully selfconsistent microscopic description of nuclear phemomena using general many-body techniques can be treated on the numerical level. We considered several different systems to indicate as much as possible the present possibilities and limits of the theory as well as of the numerical techniques. (orig./HSI)

  10. Interacting sp-boson model with isospin: an unified description of giant multipole resonances and other collective motions

    International Nuclear Information System (INIS)

    Chen, C.H.-T.

    1980-10-01

    A unified description of the following classes of nuclear collective states in terms of an interacting sp-boson model is proposed: (i) Low-lying collective states in the light nuclei, both odd-odd and even-even; (ii) Giant multipole resonances (GMR), and (iii) pairing collective motions. (Author) [pt

  11. Ground motion prediction needs for nuclear engineering design

    International Nuclear Information System (INIS)

    Hadjian, A.H.

    1985-01-01

    The basic design philosophy of nuclear power plants stipulates that the risk to the public be as low as reasonably achievable. As a result of this philosophy, the seismic design of nuclear power plants has tended, over time, to diverge from that of other engineered structures. The emphasis at the present time is to specify ground motion at a nuclear facility site as realistically as possible and to design all safety-related structures to respond to the specified ground motion in the elastic range. The characteristics of this realistic design ground motion are discussed and present prediction needs identified

  12. Cold or hot, stable or unstable collective nuclear motion

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Lacroix, D.; Jacquot, B.; Colonna, M.; Ayik, S.

    1999-01-01

    We present a general discussion of the mean field dynamics of finite nuclei prepared under extreme of temperature and pressure. Many features of the dynamics are carefully studied such as the collective expansion, the evaporation process, the different time-scale. We show that under the thermal pressure and the effect of the compression, the system may reach low density regions where it may become unstable. Early development of the instabilities in a dilute nuclear source in investigated using a finite temperature quantal Rpa approach for different systems. The growth rates of the unstable collective modes are determining by solving a dispersion relation. Which is obtained by parameterizing the transition density in terms of its multipole moments. Under typical conditions of a dilute finite system at moderate temperatures the dispersion relation exhibits an ultraviolet cut-off. As a result, only a finite number of multiple modes becomes unstable , and the number of the unstable collective modes increases with the size of the source. Calculations indicate that for an expanding source, unstable modes show a transition from surface to volume character. (author)

  13. Velocity fields and transition densities in nuclear collective modes

    Energy Technology Data Exchange (ETDEWEB)

    Stringari, S [Dipartimento di Matematica e Fisica, Libera Universita di Trento, Italy

    1979-08-13

    The shape of the deformations occurring in nuclear collective modes is investigated by means of a microscopic approach. Analytical solutions of the equations of motion are obtained by using simplified nuclear potentials. It is found that the structure of the velocity field and of the transition density of low-lying modes is considerably different from the predictions of irrotational hydrodynamic models. The low-lying octupole state is studied in particular detail by using the Skyrme force.

  14. Master equations in the microscopic theory of nuclear collective dynamics

    International Nuclear Information System (INIS)

    Matsuo, M.; Sakata, F.; Marumori, T.; Zhuo, Y.

    1988-07-01

    In the first half of this paper, the authors describe briefly a recent theoretical approach where the mechanism of the large-amplitude dissipative collective motions can be investigated on the basis of the microscopic theory of nuclear collective dynamics. Namely, we derive the general coupled master equations which can disclose, in the framework of the TDHF theory, not only non-linear dynamics among the collective and the single-particle modes of motion but also microscopic dynamics responsible for the dissipative processes. In the latter half, the authors investigate, without relying on any statistical hypothesis, one possible microscopic origin which leads us to the transport equation of the Fokker-Planck type so that usefullness of the general framework is demonstrated. (author)

  15. Locust Collective Motion and Its Modeling.

    Directory of Open Access Journals (Sweden)

    Gil Ariel

    2015-12-01

    Full Text Available Over the past decade, technological advances in experimental and animal tracking techniques have motivated a renewed theoretical interest in animal collective motion and, in particular, locust swarming. This review offers a comprehensive biological background followed by comparative analysis of recent models of locust collective motion, in particular locust marching, their settings, and underlying assumptions. We describe a wide range of recent modeling and simulation approaches, from discrete agent-based models of self-propelled particles to continuous models of integro-differential equations, aimed at describing and analyzing the fascinating phenomenon of locust collective motion. These modeling efforts have a dual role: The first views locusts as a quintessential example of animal collective motion. As such, they aim at abstraction and coarse-graining, often utilizing the tools of statistical physics. The second, which originates from a more biological perspective, views locust swarming as a scientific problem of its own exceptional merit. The main goal should, thus, be the analysis and prediction of natural swarm dynamics. We discuss the properties of swarm dynamics using the tools of statistical physics, as well as the implications for laboratory experiments and natural swarms. Finally, we stress the importance of a combined-interdisciplinary, biological-theoretical effort in successfully confronting the challenges that locusts pose at both the theoretical and practical levels.

  16. Summary of ground motion prediction results for Nevada Test Site underground nuclear explosions related to the Yucca Mountain project

    International Nuclear Information System (INIS)

    Walck, M.C.

    1996-10-01

    This report summarizes available data on ground motions from underground nuclear explosions recorded on and near the Nevada Test Site, with emphasis on the ground motions recorded at stations on Yucca Mountain, the site of a potential high-level radioactive waste repository. Sandia National Laboratories, through the Weapons Test Seismic Investigations project, collected and analyzed ground motion data from NTS explosions over a 14-year period, from 1977 through 1990. By combining these data with available data from earlier, larger explosions, prediction equations for several ground motion parameters have been developed for the Test Site area for underground nuclear explosion sources. Also presented are available analyses of the relationship between surface and downhole motions and spectra and relevant crustal velocity structure information for Yucca Mountain derived from the explosion data. The data and associated analyses demonstrate that ground motions at Yucca Mountain from nuclear tests have been at levels lower than would be expected from moderate to large earthquakes in the region; thus nuclear explosions, while located relatively close, would not control seismic design criteria for the potential repository

  17. Summary of ground motion prediction results for Nevada Test Site underground nuclear explosions related to the Yucca Mountain project

    Energy Technology Data Exchange (ETDEWEB)

    Walck, M.C.

    1996-10-01

    This report summarizes available data on ground motions from underground nuclear explosions recorded on and near the Nevada Test Site, with emphasis on the ground motions recorded at stations on Yucca Mountain, the site of a potential high-level radioactive waste repository. Sandia National Laboratories, through the Weapons Test Seismic Investigations project, collected and analyzed ground motion data from NTS explosions over a 14-year period, from 1977 through 1990. By combining these data with available data from earlier, larger explosions, prediction equations for several ground motion parameters have been developed for the Test Site area for underground nuclear explosion sources. Also presented are available analyses of the relationship between surface and downhole motions and spectra and relevant crustal velocity structure information for Yucca Mountain derived from the explosion data. The data and associated analyses demonstrate that ground motions at Yucca Mountain from nuclear tests have been at levels lower than would be expected from moderate to large earthquakes in the region; thus nuclear explosions, while located relatively close, would not control seismic design criteria for the potential repository.

  18. Nuclear structure 1985

    International Nuclear Information System (INIS)

    Broglia, R.; Hagemann, G.; Herskind, B.

    1985-01-01

    These proceedings of the Niels Bohr Centennial Conference contains 40 lectures in nuclear physics ranging over the following subjects: single particle motion; collective motion at low excitation energy; collective motion at high angular momentum; giant resonances and nuclear forces. (G.J.P.)

  19. A comparison between the adiabatic time dependent Hartree-Fock and the generator coordinate methods for the description of nuclear collective motion

    International Nuclear Information System (INIS)

    Villars, F.

    1975-01-01

    The objective of the work is to draw attention to the essential equivalence of the two apparently quite distinct ways of describing nuclear collective dyanmics, the adiabatic time-dependent Hartree-Fock method (ADTHF) on the one hand, and the Generator Coordinate (GC) method on the other hand. To demonstrate this relation, an analysis of the simplest case, in which collective motion is described by a single collective para- meter q(t) is presented. In the ATDHF approach, two self-consistency conditions are obtained; the resultant expressions for the collective potential and kinetic energies represent a special case of the more general results of Baranger and Veneroni. In the G.C. approach to the same system (with the same collective parameter q), the narrow overlap approximation must be made, as the counterpart of the adiabatic approximation in the TDHF method. In its conventional form, the G.C. method leads to a different expression for the collective kinetic energy. It is shown however, that a simple generalization of the G.C.-wave function leads to corrections determined by a variational principle. In leading order, the corrected expression for the collective kinetic energy is identical with the TDHF result In both cases, the collective inertia is determined by a self-consistent cranking formula

  20. Theoretical research in nuclear structure and nuclear collective motion: Progress report for the period March 1, 1988--February 29, 1989

    International Nuclear Information System (INIS)

    Klein, A.

    1989-01-01

    This paper discusses the following topics: Large amplitude collective motion; Boson mappings of shell model algebras; Semiclassical approximations, TDHF, and heavy ion scattering; New approach to effective interactions; and Bound states in quantum electrodynamics

  1. Large amplitude collective nuclear motion and soliton concept

    International Nuclear Information System (INIS)

    Kartavenko, V.G.; Joint Inst. for Nuclear Research, Dubna

    1993-01-01

    An application of a soliton theory methods to some nonlinear problems in low and intermediate energies (E ∼ 10--100MeV/nucleon) nucleus - nucleus collisions are presented. Linear and nonlinear excitations of the nuclear density are investigated in the framework of nuclear hydrodynamics. The problem of dynamical instability and clusterization phenomena in a breakup of excited nuclear systems are considered from the points of view of a soliton concept

  2. Quantum theory of dynamical collective subspace for large-amplitude collective motion

    International Nuclear Information System (INIS)

    Sakata, Fumihiko; Marumori, Toshio; Ogura, Masanori.

    1986-03-01

    By placing emphasis on conceptual correspondence to the ''classical'' theory which has been developed within the framework of the time-dependent Hartree-Fock theory, a full quantum theory appropriate for describing large-amplitude collective motion is proposed. A central problem of the quantum theory is how to determine an optimal representation called a dynamical representation; the representation is specific for the collective subspace where the large-amplitude collective motion is replicated as satisfactorily as possible. As an extension of the classical theory where the concept of an approximate integral surface plays an important role, the dynamical representation is properly characterized by introducing a concept of an approximate invariant subspace of the Hamiltonian. (author)

  3. Microscopic analysis of nuclear collective motions in terms of the boson expansion theory. Pt. 1

    International Nuclear Information System (INIS)

    Sakamoto, Hideo; Kishimoto, Teruo

    1988-01-01

    A normal-ordered linked-cluster boson expansion theory, previously worked out by one of the authors (T.K.) and Tamura, has been developed further by reformulating it in a 'physical' quasiparticle subspace which contains no spurious particle-number excitation modes. The expansion coefficients of the collective hamiltonian for low-lying quadrupole motions are determined starting from a microscopic fermion hamiltonian including self-consistent higher-order (many-body) interactions derived in our previous work. The contributions from the non-collective states with all possible non-collective one-boson excitations having I π = 0 + -4 + , which can directly couple to the collective states with one or two phonons, are taken into account in a systematic and compact way. (orig.)

  4. Quantum self-organization and nuclear collectivities

    Science.gov (United States)

    Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

    2018-02-01

    The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The outcome of the collective mode is determined basically by the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger gaps between relevant single particle states. Thus, the single-particle state and the collective mode are “enemies” each other. However, the nuclear forces are demonstrated to be rich enough so as to enhance relevant collective mode by reducing the resistance power by changing singleparticle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, when the quantum self-organization occurs, single-particle energies can be self-organized, being enhanced by (i) two quantum liquids, e.g., protons and neutrons, (ii) two major force components, e.g., quadrupole interaction (to drive collective mode) and monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger. The quantum self-organization is a general phenomenon, and is expected to be found in other quantum systems.

  5. A microscopic derivation of nuclear collective rotation-vibration model and its application to nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gulshani, P., E-mail: matlap@bell.net [NUTECH Services, 3313 Fenwick Crescent, Mississauga, Ontario, L5L 5N1 (Canada)

    2016-07-07

    We derive a microscopic version of the successful phenomenological hydrodynamic model of Bohr-Davydov-Faessler-Greiner for collective rotation-vibration motion of an axially symmetric deformed nucleus. The derivation is not limited to small oscillation amplitude. The nuclear Schrodinger equation is canonically transformed to collective co-ordinates, which is then linearized using a constrained variational method. The associated constraints are imposed on the wavefunction rather than on the particle co-ordinates. The approach yields three self-consistent, time-reversal invariant, cranking-type Schrodinger equations for the rotation-vibration and intrinsic motions, and a self-consistency equation. For harmonic oscillator mean-field potentials, these equations are solved in closed forms for excitation energy, cut-off angular momentum, and other nuclear properties for the ground-state rotational band in some deformed nuclei. The results are compared with measured data.

  6. Optimum collective submanifold in resonant cases by the self-consistent collective-coordinate method for large-amplitude collective motion

    International Nuclear Information System (INIS)

    Hashimoto, Y.; Marumori, T.; Sakata, F.

    1987-01-01

    With the purpose of clarifying characteristic difference of the optimum collective submanifolds in nonresonant and resonant cases, we develop an improved method of solving the basic equations of the self-consistent collective-coordinate (SCC) method for large-amplitude collective motion. It is shown that, in the resonant cases, there inevitably arise essential coupling terms which break the maximal-decoupling property of the collective motion, and we have to extend the optimum collective submanifold so as to properly treat the degrees of freedom which bring about the resonances

  7. Shape matters: Near-field fluid mechanics dominate the collective motions of ellipsoidal squirmers.

    Science.gov (United States)

    Kyoya, K; Matsunaga, D; Imai, Y; Omori, T; Ishikawa, T

    2015-12-01

    Microswimmers show a variety of collective motions. Despite extensive study, questions remain regarding the role of near-field fluid mechanics in collective motion. In this paper, we describe precisely the Stokes flow around hydrodynamically interacting ellipsoidal squirmers in a monolayer suspension. The results showed that various collective motions, such as ordering, aggregation, and whirls, are dominated by the swimming mode and the aspect ratio. The collective motions are mainly induced by near-field fluid mechanics, despite Stokes flow propagation over a long range. These results emphasize the importance of particle shape in collective motion.

  8. Trend-Centric Motion Visualization: Designing and Applying a New Strategy for Analyzing Scientific Motion Collections.

    Science.gov (United States)

    Schroeder, David; Korsakov, Fedor; Knipe, Carissa Mai-Ping; Thorson, Lauren; Ellingson, Arin M; Nuckley, David; Carlis, John; Keefe, Daniel F

    2014-12-01

    In biomechanics studies, researchers collect, via experiments or simulations, datasets with hundreds or thousands of trials, each describing the same type of motion (e.g., a neck flexion-extension exercise) but under different conditions (e.g., different patients, different disease states, pre- and post-treatment). Analyzing similarities and differences across all of the trials in these collections is a major challenge. Visualizing a single trial at a time does not work, and the typical alternative of juxtaposing multiple trials in a single visual display leads to complex, difficult-to-interpret visualizations. We address this problem via a new strategy that organizes the analysis around motion trends rather than trials. This new strategy matches the cognitive approach that scientists would like to take when analyzing motion collections. We introduce several technical innovations making trend-centric motion visualization possible. First, an algorithm detects a motion collection's trends via time-dependent clustering. Second, a 2D graphical technique visualizes how trials leave and join trends. Third, a 3D graphical technique, using a median 3D motion plus a visual variance indicator, visualizes the biomechanics of the set of trials within each trend. These innovations are combined to create an interactive exploratory visualization tool, which we designed through an iterative process in collaboration with both domain scientists and a traditionally-trained graphic designer. We report on insights generated during this design process and demonstrate the tool's effectiveness via a validation study with synthetic data and feedback from expert musculoskeletal biomechanics researchers who used the tool to analyze the effects of disc degeneration on human spinal kinematics.

  9. Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jie; Guehr, Markus; Shen, Xiaozhe; Li, Renkai; Vecchione, Theodore; Coffee, Ryan; Corbett, Jeff; Fry, Alan; Hartmann, Nick; Hast, Carsten; Hegazy, Kareem; Jobe, Keith; Makasyuk, Igor; Robinson, Joseph; Robinson, Matthew S.; Vetter, Sharon; Weathersby, Stephen; Yoneda, Charles; Wang, Xijie; Centurion, Martin

    2016-10-03

    Observing the motion of the nuclear wave packets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wave packet in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a precision 0.07 Å and temporal resolution of 230 fs full width at half maximum. The method is not only sensitive to the position but also the shape of the nuclear wave packet.

  10. Microscopic theory of nuclear collective rotation

    International Nuclear Information System (INIS)

    Wunner, G.; Ruder, H.; Herold, H.; Reinecke, M.

    1980-01-01

    Various methods for calculating nuclear moments of inertia have been investigated, from the point of view of their possible connection with special choices of collective variables, using the method of specific decoupling (SD), which introduces a body-fixed frame in such a way that, for a given internal state, the best possible decoupling of internal and collective motion is obtained, and which for any definition of the body-fixed frame provides a well defined expression for the moment of inertia. The internal degrees of freedom are described using (1) intrinsic densities and (2) intrinsic wavefunctions. It is shown that several frequently used formulae for calculating the moment of inertia can be traced back to specific definitions of the internal frame and the extremum principle of SD makes possible a lucid evaluation of the magnitudes of these moments of inertia relative to each other as well as with respect to the corresponding values of the rigid and the irrotational moments of inertia. (author)

  11. Field theory of large amplitude collective motion. A schematic model

    International Nuclear Information System (INIS)

    Reinhardt, H.

    1978-01-01

    By using path integral methods the equation for large amplitude collective motion for a schematic two-level model is derived. The original fermion theory is reformulated in terms of a collective (Bose) field. The classical equation of motion for the collective field coincides with the time-dependent Hartree-Fock equation. Its classical solution is quantized by means of the field-theoretical generalization of the WKB method. (author)

  12. Collective Motion in Behaviorally Heterogeneous Systems

    Science.gov (United States)

    Copenhagen, Katherine

    Collective motion is a widespread phenomenon in nature where individuals actively propel themselves, gather together and move as a group. Some examples of collective motion are bird flocks, fish schools, bacteria swarms, cell clusters, and crowds of people. Many models seek to understand the effects of activity in collective systems including things such as environmental disorder, density, and interaction details primarily at infinite size limits and with uniform populations. In this dissertation I investigate the effects of finite sizes and behavioral heterogeneity as it exists in nature. Behavioral heterogeneity can originate from several different sources. Mixed populations of individuals can have inherently different behaviors such as mutant bacteria, injured fish, or agents that prefer individualistic behavior over coordinated motion. Alternatively, agents may modify their own behavior based on some local environmental dependency, such as local substrate, or density. In cases such as mutant cheaters in bacteria or malfunctioning drones in swarms, mixed populations of behaviorally heterogeneous agents can be modelled as arising in the form of aligning and non-aligning agents. When this kind of heterogeneity is introduced, there is a critical carrying capacity of non-aligners above which the system is unable to form a cohesive ordered group. However, if the cohesion of the group is relaxed to allow for fracture, the system will actively sort out non-aligning agents the system will exist at a critical non-aligner fraction. A similar heterogeneity could result in a mixture of high and low noise individuals. In this case there is also a critical carry capacity beyond which the system is unable to reach an ordered state, however the nature of this transition depends on the model details. Agents which are part of an ordered collective may vary their behavior as the group changes environments such as a flock of birds flying into a cloud. Using a unique model of a

  13. Large amplitude nuclear collective motion and the quantized ATDHF theory

    International Nuclear Information System (INIS)

    Provoost, D.

    1986-01-01

    Several nuclear systems are studied within the quantized ATDHF theory. For the α- 16 O system, after construction of the wave functions along the collective path, a collective Schroedinger equation, including quantum corrections, is derived in the Gaussian Overlap Approximation and solved for scattering and bound states. The elastic scattering cross sections agree well with experiment at low energies. An alternative possibility is to perform angular momentum projections on the wave functions and to insert the Hamilton- and normkernels in the Griffin-Hill-Wheeler equation. The widths of the resonances are extracted from the poles of the S-matrix in the complex energy plane. Good agreement is obtained for the energies of even-parity levels but the odd-parity levels are shifted in energy as compared with experiment. The origin of this discrepancy is to be found in the BKN interaction which is not able to reproduce the binding energies of α, 16 O and 20 Ne. For the α- 12 C system, with a deformed fragment, the agreement with experiment is poor. One difficulty is the problem of how to link the different paths of the different configurations which are possible for the α- 12 C system. All calculations have been performed on a three-dimensional lattice. (MCB)

  14. A quasi-relativistic treatment of nuclear motion in atoms and molecules

    International Nuclear Information System (INIS)

    Chen, W.Q.; Cook, A.H.

    1987-01-01

    A quasi-relativistic Hamiltonian for an atom and a molecule is constructed. The Foldy-Wouthuysen transformation is applied to the Hamiltonian. Consequently, extra terms from interactions between the electronic motion and the nuclear magnetic field contributing to the Darwin term and the spin-orbit coupling are derived explicitly. Moreover, the coupling between nuclear motion and the spin of the electron is obtained. (author)

  15. Synchronization and collective motion of globally coupled Brownian particles

    International Nuclear Information System (INIS)

    Sevilla, Francisco J; Heiblum-Robles, Alexandro; Dossetti, Victor

    2014-01-01

    In this work, we study a system of passive Brownian (non-self-propelled) particles in two dimensions, interacting only through a social-like force (velocity alignment in this case) that resembles Kuramoto's coupling among phase oscillators. We show that the kinematical stationary states of the system go from a phase in thermal equilibrium with no net flux of particles, to far-from-equilibrium phases exhibiting collective motion by increasing the coupling among particles. The mechanism that leads to the instability of the equilibrium phase relies on the competition between two time scales, namely, the mean collision time of the Brownian particles in a thermal bath and the time it takes for a particle to orient its direction of motion along the direction of motion of the group. Our results show a clear connection between collective motion and the Kuramoto model for synchronization, in our case, for the direction of motion of the particles. (paper)

  16. Self-consistent transport coefficients for average collective motion at moderately high temperatures

    International Nuclear Information System (INIS)

    Yamaji, Shuhei; Hofmann, H.; Samhammer, R.

    1987-01-01

    Linear response theory is applied to compute the coefficients for inertia, friction and local stiffness for slow, large scale nuclear collective motion. It is shown how these coefficients can be defined within a locally harmonic approximation. The latter allows to study the implications arising from a finite local collective frequency. It is only for temperatures around 2 MeV that the zero frequency limit becomes a fair approximation. Friction is found to have a marked temperature dependence. The numerical computations are performed on the basis of a two-center shell model, but allowing the particles and holes to become dressed through effects of the medium. The dependence of the transport coefficients on the parameters of these self-energies is studied. It is argued that the uncertainties are smaller than a factor of 2. (orig.)

  17. Collective motion in quantum many-body systems

    Energy Technology Data Exchange (ETDEWEB)

    Haemmerling, Jens

    2011-06-07

    We study the emergence of collective dynamics in the integrable Hamiltonian system of two finite ensembles of coupled harmonic oscillators. After identification of a collective degree of freedom, the Hamiltonian is mapped onto a model of Caldeira-Leggett type, where the collective coordinate is coupled to an internal bath of phonons. In contrast to the usual Caldeira-Leggett model, the bath in the present case is part of the system. We derive an equation of motion for the collective coordinate which takes the form of a damped harmonic oscillator. We show that the distribution of quantum transition strengths induced by the collective mode is determined by its classical dynamics. This allows us to derive the spreading for the collective coordinate from first principles. After that we study the interplay between collective and incoherent single-particle motion in a model of two chains of particles whose interaction comprises a non-integrable part. In the perturbative regime, but for a general form of the interaction, we calculate the Fourier transform of the time correlation for the collective coordinate. We obtain the remarkable result that it always has a unique semi-classical interpretation. We show this by a proper renormalization procedure which also allows us to map the non-integrable system to the integrable model of Caldeira-Leggett-type considered previously in which the bath is part of the system.

  18. Methodology to evaluate the site standard seismic motion to a nuclear facility

    International Nuclear Information System (INIS)

    Soares, W.A.

    1983-01-01

    For the seismic design of nuclear facilities, the input motion is normally defined by the predicted maximum ground horizontal acceleration and the free field ground response spectrum. This spectrum is computed on the basis of records of strong motion earthquakes. The pair maximum acceleration-response spectrum is called the site standard seismic motion. An overall view of the subjects involved in the determination of the site standard seismic motion to a nuclear facility is presented. The main topics discussed are: basic principles of seismic instrumentation; dynamic and spectral concepts; design earthquakes definitions; fundamentals of seismology; empirical curves developed from prior seismic data; available methodologies and recommended procedures to evaluate the site standard seismic motion. (Author) [pt

  19. Self-consistent collective-coordinate method for ''maximally-decoupled'' collective subspace and its boson mapping: Quantum theory of ''maximally-decoupled'' collective motion

    International Nuclear Information System (INIS)

    Marumori, T.; Sakata, F.; Maskawa, T.; Une, T.; Hashimoto, Y.

    1983-01-01

    The main purpose of this paper is to develop a full quantum theory, which is capable by itself of determining a ''maximally-decoupled'' collective motion. The paper is divided into two parts. In the first part, the motivation and basic idea of the theory are explained, and the ''maximal-decoupling condition'' on the collective motion is formulated within the framework of the time-dependent Hartree-Fock theory, in a general form called the invariance principle of the (time-dependent) Schrodinger equation. In the second part, it is shown that when the author positively utilize the invariance principle, we can construct a full quantum theory of the ''maximally-decoupled'' collective motion. This quantum theory is shown to be a generalization of the kinematical boson-mapping theories so far developed, in such a way that the dynamical ''maximal-decoupling condition'' on the collective motion is automatically satisfied

  20. TDHF and fluid dynamics of nuclear collective motions

    International Nuclear Information System (INIS)

    Di Nardo, M.; Di Toro, M.; Giansiracusa, G.; Lombardo, U.; Russo, G.

    1983-01-01

    The nuclear fluid dynamical equations are derived from a mean field description of the nuclear dynamics. Simple approximate solutions, corresponding to generalized scaling modes, are worked out for rotations and vibrations, with the evaluation of inertial parameters and flow patterns. Giant resonances are shown to be quite well described within an irrotational ansatz, which is equivalent to a lowest multipoles (up to lsub(max)=2) distortion of the momentum distribution. The physical meaning of a higher order truncation of the TDHF-Fluid-Dynamics chain is finally discussed with its implication on low lying states and on some description of the Landau damping. (author)

  1. Open questions on nuclear collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Frauendorf, S., E-mail: sfrauend@nd.edu [Department of Physics, University Notre Dame, IN 46557 (United States)

    2016-07-07

    The status of the macroscopic and microscopic description of the collective quadrupole modes is reviewed, where limits due to non-adiabaticity and decoherence are exposed. The microscopic description of the yrast states in vibrator-like nuclei in the framework of the rotating mean field is presented.

  2. Atto-second control of collective electron motion in plasmas

    International Nuclear Information System (INIS)

    Borot, Antonin; Malvache, Arnaud; Chen, Xiaowei; Jullien, Aurelie; Lopez-Martens, Rodrigo; Geindre, Jean-Paul; Audebert, Patrick; Mourou, Gerard; Quere, Fabien

    2012-01-01

    Today, light fields of controlled and measured waveform can be used to guide electron motion in atoms and molecules with atto-second precision. Here, we demonstrate atto-second control of collective electron motion in plasmas driven by extreme intensity (approximate to 10 18 W cm -2 ) light fields. Controlled few-cycle near-infrared waves are tightly focused at the interface between vacuum and a solid-density plasma, where they launch and guide sub-cycle motion of electrons from the plasma with characteristic energies in the multi-kilo-electron-volt range-two orders of magnitude more than has been achieved so far in atoms and molecules. The basic spectroscopy of the coherent extreme ultraviolet radiation emerging from the light-plasma interaction allows us to probe this collective motion of charge with sub-200 as resolution. This is an important step towards atto-second control of charge dynamics in laser-driven plasma experiments. (authors)

  3. Microscopic theory of dynamical subspace for large amplitude collective motion

    International Nuclear Information System (INIS)

    Sakata, Fumihiko; Marumori, Toshio; Ogura, Masanori.

    1986-01-01

    A full quantum theory appropriate for describing large amplitude collective motion is proposed by exploiting the basic idea of the semi-classical theory so far developed within the time-depedent Hartree-Fock theory. A central problem of the quantum theory is how to determine an optimal representation called a dynamical representation specific for the collective subspace where the large amplitude collective motion is replicated as precisely as possible. As an extension of the semi-classical theory where the concept of an approximate integral surface played an important role, the collective subspace is properly characterized by introducing a concept of an approximate invariant subspace of the Hamiltonian. (author)

  4. X-ray cinematography on the nuclear fuel and cladding motion diagnostics

    International Nuclear Information System (INIS)

    Mizuta, Hiroshi; Uruwashi, Shinichi.

    1979-01-01

    X-ray cinematography has been used for monitoring fuel motion in the out-of-pile fuel pin joule melting experiments for nuclear, liquid metal cooled fast breeder reactor, safety studies related to fuel pin failure, initial fuel motion and thermal fuel-coolant interaction (FCI) of the hypothetical core distractive accident. In order to visually observe the nuclear fuel motion, the X-ray cinematography system consists of an X-ray source located about 5 cm from the test section and an image intensifier located at a corresponding position on the opposite side of the test section. The image from the image intensifier has been recorded both with a high speed camera and video recorder. (author)

  5. Collective motion and giant resonances

    International Nuclear Information System (INIS)

    Wilhelmi, Z.; Kicinska-Habior, M.

    1984-01-01

    The report contains 15 papers devoted to problems of giant collective excitations of nuclei, heavy-ion induced reactions and their bearing on various aspects of nuclear structure. In some of them the numerical data are given. (A.S.)

  6. String-like collective motion in the α- and β-relaxation of a coarse-grained polymer melt

    Science.gov (United States)

    Pazmiño Betancourt, Beatriz A.; Starr, Francis W.; Douglas, Jack F.

    2018-03-01

    Relaxation in glass-forming liquids occurs as a multi-stage hierarchical process involving cooperative molecular motion. First, there is a "fast" relaxation process dominated by the inertial motion of the molecules whose amplitude grows upon heating, followed by a longer time α-relaxation process involving both large-scale diffusive molecular motion and momentum diffusion. Our molecular dynamics simulations of a coarse-grained glass-forming polymer melt indicate that the fast, collective motion becomes progressively suppressed upon cooling, necessitating large-scale collective motion by molecular diffusion for the material to relax approaching the glass-transition. In each relaxation regime, the decay of the collective intermediate scattering function occurs through collective particle exchange motions having a similar geometrical form, and quantitative relationships are derived relating the fast "stringlet" collective motion to the larger scale string-like collective motion at longer times, which governs the temperature-dependent activation energies associated with both thermally activated molecular diffusion and momentum diffusion.

  7. Control Strategies for Guided Collective Motion

    Science.gov (United States)

    2015-02-27

    J.K. Parrish , “Oscillator models and collective motion,” IEEE Control Systems Magzine, Vol. 27, 2007, pp. 89-105. [18] S. H. Strogatz , “From Kuramoto...Automatic Control, 54(2), 2009, pp. 353-357. [21] H. Hong and S. H. Strogatz , “Kuramoto Model of Coupled Oscillators with Positive and Negative...2013) provided similar results by utilizing a modified Kuramoto model ( Strogatz (2000)). Paley (2008) proposed a Lyapunov-based design methodology to

  8. A test case of computer aided motion planning for nuclear maintenance operation

    International Nuclear Information System (INIS)

    Schmitzberger, E.; Bouchet, J.L.; Schmitzberger, E.

    2001-01-01

    Needs for improved tools for nuclear power plant maintenance preparation are expressed by EDF engineering. These are an easier and better management of logistics constraints such as free spaces for motions or handling tasks. The lack of generic or well suited tools and the specificity of nuclear maintenance operation have led EDF R and D to develop its own motion planning tools in collaboration with LAAS-CNRS, Utrecht University and the software publisher CADCENTRE within the framework of the three years Esprit LTR project MOLOG. EDF users needs will be summed up in the first part of the paper under the title ''Motion feasibility studies for maintenance operation'' and then compared to the current industrial offer in the ''Software's background'''s part. The definition and objectives ''Towards motion planning tools'' follows. It explains why maintenance preparation pertains to automatic motion planning and how it makes studies much simpler. The ''MOLOG's Benchmark and first result'''s part describes the test-case used to evaluate the MOLOG project and gives an outlook at the results obtained so far. (author)

  9. The effect of motion on dynamic nuclear polarization: A new theoretical development

    International Nuclear Information System (INIS)

    Coffino, A.R.

    1989-01-01

    Dynamic Nuclear Polarization (DNP) is a magnetic resonance technique which uses two different radiation sources: a radiofrequency field and microwave field to radiate nuclei and electrons, respectively. The DNP experiment probes the nature of the interaction between nuclei and electrons. The maximum of the resonance signal from the nucleus is plotted as a function of microwave frequency for the case of the microwaves on and off. The DNP signal is the ratio of these two signals and is termed the enhancement of the nuclear signal. This thesis considers the theory of the DNP signal based on the density matrix formulation of the Stochastic Liouville Equation, which incorporates the spin-spin interactions, spin-field interactions and a stochastic dynamics process which modulates these interactions. The case of one electron coupled to one spin one-half nucleus is considered. Such a formulation has never been developed. The thesis demonstrates that previous partial theories have attempted to incorporate dynamics have been incorrect. This theoretical development demonstrates, for the first time, how dynamics affects the DNP lineshapes. This theory predicts that DNP spectra change smoothly from the no motion to the fast motion region, and reproduces the known analytic answers in both the no-motion and the fast-motion limit. The most important observation of the results is that a DNP signal for a motional rate in the intermediate motional region looks like a superposition of a no-motion and fast-motion signal

  10. A test case of computer aided motion planning for nuclear maintenance operation

    Energy Technology Data Exchange (ETDEWEB)

    Schmitzberger, E.; Bouchet, J.L. [Electricite de France (EDF), Dept. Surveillance Diagnostic Maintenance, 78 - Chatou (France); Schmitzberger, E. [Institut National Polytechnique, CRAN, 54 - Vandoeuvre les Nancy (France)

    2001-07-01

    Needs for improved tools for nuclear power plant maintenance preparation are expressed by EDF engineering. These are an easier and better management of logistics constraints such as free spaces for motions or handling tasks. The lack of generic or well suited tools and the specificity of nuclear maintenance operation have led EDF R and D to develop its own motion planning tools in collaboration with LAAS-CNRS, Utrecht University and the software publisher CADCENTRE within the framework of the three years Esprit LTR project MOLOG. EDF users needs will be summed up in the first part of the paper under the title ''Motion feasibility studies for maintenance operation'' and then compared to the current industrial offer in the ''Software's background'''s part. The definition and objectives ''Towards motion planning tools'' follows. It explains why maintenance preparation pertains to automatic motion planning and how it makes studies much simpler. The ''MOLOG's Benchmark and first result'''s part describes the test-case used to evaluate the MOLOG project and gives an outlook at the results obtained so far. (author)

  11. Equations-of-motion approach to a quantum theory of large-amplitude collective motion

    International Nuclear Information System (INIS)

    Klein, A.

    1984-01-01

    The equations-of-motion approach to large-amplitude collective motion is implemented both for systems of coupled bosons, also studied in a previous paper, and for systems of coupled fermions. For the fermion case, the underlying formulation is that provided by the generalized Hartree-Fock approximation (or generalized density matrix method). To obtain results valid in the semi-classical limit, as in most previous work, we compute the Wigner transform of quantum matrices in the representation in which collective coordinates are diagonal and keep only the leading contributions. Higher-order contributions can be retained, however, and, in any case, there is no ambiguity of requantization. The semi-classical limit is seen to comprise the dynamics of time-dependent Hartree-Fock theory (TDHF) and a classical canonicity condition. By utilizing a well-known parametrization of the manifold of Slater determinants in terms of classical canonical variables, we are able to derive and understand the equations of the adiabatic limit in full parallelism with the boson case. As in the previous paper, we can thus show: (i) to zero and first order in the adiabatic limit the physics is contained in Villar's equations; (ii) to second order there is consistency and no new conditions. The structure of the solution space (discussed thoroughly in the previous paper) is summarized. A discussion of associated variational principles is given. A form of the theory equivalent to self-consistent cranking is described. A method of solution is illustrated by working out several elementary examples. The relationship to previsous work, especially that of Zelevinsky and Marumori and coworkers is discussed briefly. Three appendices deal respectively with the equations-of-motion method, with useful properties of Slater determinants, and with some technical details associated with the fermion equations of motion. (orig.)

  12. Nuclear wobbling motion and properties of E-2 transitions

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Y R [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Matsuzaki, M [Fukuoka Univ. (Japan)

    1992-08-01

    The nuclear wobbling motion associated with the static triaxial deformation are discussed based on a microscopic theory. Properties of the E2-transitions between the one-phonon wobbling band and the yrast (vacuum) band are studied and their characteristic features are suggested. (author). 11 refs., 3 figs.

  13. Basis states for the rotational and vibrational limits of nuclear collective motion

    International Nuclear Information System (INIS)

    Vanagas, V.; Alishauskas, S.; Kalinauskas, R.; Nadzhakov, E.

    1980-01-01

    Basis states characterized by quantum numbers traditionally used in the rotational and the vibrational limits are treated in an unified way. An explicit basis construction in the Hilbert space of the collective phenomenological nuclear Hamiltonian generalized to six degrees of freedom in both limits is given. This generalization reduces to including an additional degree of freedom allowing to treat both cases within a collective substance of the complete many-body Hilbert space. A group-theoretical approach is applied. From this point of view the problem is reduced to the construction of a set of U(6)-irreducible states labelled by quantum numbers of two special chains of subgroups adapted for the rotational and vibrational limits. In particular, the generalization is more complicated in the case of the chain for the rotational limits. The explicit construction of a basis for both limits is carried out in two steps: 1) construction of the highest weight state for corresponding group irreducible representation - in the case of the rotational limit U(3) and of the vibrational limit O(5); 2) generating a complete set of states by the projection technique. In this framework it is possible to diagonalize a general phenomenological Hamiltonian in cases different from both limits. It is also possible to calculate transition probabilities induced by any physical quantity

  14. Geometry of the self-consistent collective-coordinate method for the large-amplitude collective motion

    International Nuclear Information System (INIS)

    Sakata, Fumihiko; Marumori, Toshio; Hashimoto, Yukio; Une, Tsutomu.

    1983-05-01

    The geometry of the self-consistent collective-coordinate (SCC) method formulated within the framework of the time-dependent Hartree-Fock (TDHF) theory is investigated by associating the variational parameters with a symplectic manifold (a TDHF manifold). With the use of a canonical-variables parametrization, it is shown that the TDHF equation is equivalent to the canonical equations of motion in classical mechanics in the TDHF manifold. This enables us to investigate geometrical structure of the SCC method in the language of the classical mechanics. The SCC method turns out to give a prescription how to dynamically extract a ''maximally-decoupled'' collective submanifold (hypersurface) out of the TDHF manifold, in such a way that a certain kind of trajectories corresponding to the large-amplitude collective motion under consideration can be reproduced on the hypersurface as precisely as possible. The stability of the hypersurface at each point on it is investigated, in order to see whether the hypersurface obtained by the SCC method is really an approximate integral surface in the TDHF manifold or not. (author)

  15. Isospin effects on collective nuclear dynamics

    CERN Document Server

    Di Toro, M; Baran, V; Larionov, A B

    1999-01-01

    We suggest several ways to study properties of the symmetry term in the nuclear equation of state, EOS, from collective modes in beta-unstable nuclei. After a general discussion on compressibility and saturation density in asymmetric nuclear matter we show some predictions on the collective response based on the solution of generalized Landau dispersion relations. Isoscalar-isovector coupling, disappearance of collectivity and possibility of new instabilities in low and high density regions are discussed with accent on their relation to the symmetry term of effective forces. The onset of chemical plus mechanical instabilities in a dilute asymmetric nuclear matter is discussed with reference to new features in fragmentation reactions.

  16. Bending-Twisting Motions and Main Interactions in Nucleoplasmin Nuclear Import.

    Directory of Open Access Journals (Sweden)

    Marcos Tadeu Geraldo

    Full Text Available Alpha solenoid proteins play a key role in regulating the classical nuclear import pathway, recognizing a target protein and transporting it into the nucleus. Importin-α (Impα is the solenoid responsible for cargo protein recognition, and it has been extensively studied by X-ray crystallography to understand the binding specificity. To comprehend the main motions of Impα and to extend the information about the critical interactions during carrier-cargo recognition, we surveyed different conformational states based on molecular dynamics (MD and normal mode (NM analyses. Our model of study was a crystallographic structure of Impα complexed with the classical nuclear localization sequence (cNLS from nucleoplasmin (Npl, which was submitted to multiple 100 ns of MD simulations. Representative conformations were selected for calculating the 87 lowest frequencies NMs of vibration, and a displacement approach was applied along each NM. Based on geometric criteria, using the radius of curvature and inter-repeat angles as the reference metrics, the main motions of Impα were described. Moreover, we determined the salt bridges, hydrogen bonds and hydrophobic interactions in the Impα-NplNLS interface. Our results show the bending and twisting motions participating in the recognition of nuclear proteins, allowing the accommodation and adjustment of a classical bipartite NLS sequence. The essential contacts for the nuclear import were also described and were mostly in agreement with previous studies, suggesting that the residues in the cNLS linker region establish important contacts with Impα adjusting the cNLS backbone. The MD simulations combined with NM analysis can be applied to the Impα-NLS system to help understand interactions between Impα and cNLSs and the analysis of non-classic NLSs.

  17. Collective motion of cells mediates segregation and pattern formation in co-cultures.

    Directory of Open Access Journals (Sweden)

    Elod Méhes

    Full Text Available Pattern formation by segregation of cell types is an important process during embryonic development. We show that an experimentally yet unexplored mechanism based on collective motility of segregating cells enhances the effects of known pattern formation mechanisms such as differential adhesion, mechanochemical interactions or cell migration directed by morphogens. To study in vitro cell segregation we use time-lapse videomicroscopy and quantitative analysis of the main features of the motion of individual cells or groups. Our observations have been extensive, typically involving the investigation of the development of patterns containing up to 200,000 cells. By either comparing keratocyte types with different collective motility characteristics or increasing cells' directional persistence by the inhibition of Rac1 GTP-ase we demonstrate that enhanced collective cell motility results in faster cell segregation leading to the formation of more extensive patterns. The growth of the characteristic scale of patterns generally follows an algebraic scaling law with exponent values up to 0.74 in the presence of collective motion, compared to significantly smaller exponents in case of diffusive motion.

  18. Institute for Nuclear Theory

    International Nuclear Information System (INIS)

    Haxton, W.; Bertsch, G.; Henley, E.M.

    1993-01-01

    This report briefly discussion the following programs of the Institute for Nuclear Theory: fundamental interactions in nuclei; strangeness in hadrons and nuclei; microscopic nuclear structure theory; nuclear physics in atoms and molecules; phenomenology and lattice QCD; and large amplitude collective motion

  19. Some predicted peak ground motions for nuclear cratering explosions along the Qattara alignment in Egypt

    International Nuclear Information System (INIS)

    Bryan, J.B.

    1980-01-01

    Some predicted peak free-field ground motions at shot depth for the nuclear explosive excavation of a canal in Egypt are summarized. Peak values of displacement, velocity, acceleration, and radial stress are presented as a function of slant range from the working point. Results from two-dimensional TENSOR cratering calculations are included. Fits to ground motion measurements in other media are also shown. This summary is intended to help specify engineering design requirements for detonating nuclear explosive salvos which are required to efficiently excavate the canal. It also should be useful in guiding estimates for gage response ranges in ground motion measurements

  20. Methodology to evaluate the site standard seismic motion for a nuclear facility

    International Nuclear Information System (INIS)

    Soares, W.A.

    1983-03-01

    An overall view of the subjects involved in the determination of the site standard seismic motion to a nuclear facility is presented. The main topics discussed are: basic priciples of seismic instrumentation; dynamic and spectral concepts; design earthquakes definitions; fundamentals of seismology; empirical curves developed from prior seismic data; avalable methodologies and recommended procedures to evaluate the site standard seismic motion. (E.G.) [pt

  1. Boson models of quadrupole collective motion

    International Nuclear Information System (INIS)

    Zelevinskij, V.G.

    1985-01-01

    The subject of the lecture is the low-lying excitations of even-even (e-e) spherical nuclei. The predominant role of the quadrupole mode, which determines the structure of spectra and transitions, is obvious on the background of shell periodicity and pair correlations. Typical E2-transitions are strengthened Ω ∼ A 2/3 times in comparison with single particle evaluations. Together with the regularity of the whole picture it gives evidence about collectivization of quadrupole motion. The collective states are combined in bands, where the transition probability are especially great; frequencies ω of the strengthened transitions are small in comparison with pair separation energies of 2 E-bar ∼ 2 MeV. Thus, the description of low-lying excitations of spherical nuclei has to be based on three principles: collectivity (Ω >> 1), adiabaticity (τ ≡ ω/2E-bar << 1) and quadrupole symmetry

  2. Whole study of nuclear matter collective motion in central collisions of heavy ions of the FOPI detector; Etude complete du mouvement collectif de la matiere nucleaire dans les collisions centrales d'ions lourds avec le detecteur FOPI

    Energy Technology Data Exchange (ETDEWEB)

    Bendarag, A

    1999-07-09

    In this work we study the collective phenomena in the central collisions of heavy ions for the Au + Au, Xe + CsI and Ni + Ni systems at incident energies from 150 to 400 MeV/nucleon with the data of the FOPI detector. In order to describe completely the flow of the nuclear matter, we fit the double differential momentum distributions with two-dimensional Gaussian. We study the characteristic parameters of the collective flow (flow range, aspect ratios, flow parameter) versus the charge and the mass of the fragments as well as the incident energy and the centrality of the collisions. The transverse energy is used for selecting the central collisions. The method of the Gaussian fits requires also to reconstruct the reaction plane of the event. Then we correct the parameters for the finite number of particles effects and account for the influence of the acceptance of the detector. We confirm the importance of the thermal motion for the light charge or mass fragments and, conversely, the predominance of the collective motion for the heavy fragments. A common flow angle for all the types of particles is highlighted for the first time, demonstrating the power of the method of the Gaussian fits; The evolution of the other parameters confirms the observations done with other methods of flow analysis. These results should contribute to put constraints on the collision models and to enlarge our knowledge of the properties of the nuclear matter. (author)

  3. Strong-Field Modulated Diffraction Effects in the Correlated Electron-Nuclear Motion in Dissociating H2+

    International Nuclear Information System (INIS)

    He Feng; Becker, Andreas; Thumm, Uwe

    2008-01-01

    We show that the electronic dynamics in a molecule driven by a strong field is complex and potentially even counterintuitive. As a prototype example, we simulate the interaction of a dissociating H 2 + molecule with an intense infrared laser pulse. Depending on the laser intensity, the direction of the electron's motion between the two nuclei is found to follow or oppose the classical laser-electric force. We explain the sensitive dependence of the correlated electronic-nuclear motion in terms of the diffracting electronic momentum distribution of the dissociating two-center system. The distribution is dynamically modulated by the nuclear motion and periodically shifted in the oscillating infrared electric field

  4. Procedures for evaluation of vibratory ground motions of soil deposits at nuclear power plant sites

    International Nuclear Information System (INIS)

    1975-06-01

    According to USNRC requirements set forth in Appendix A, 10 CFR, Part 100, vibratory ground motion criteria for a nuclear plant must be based on local soil conditions, as well as on the seismicity, geology, and tectonics of the region. This report describes how such criteria can be developed by applying the latest technology associated with analytical predictions of site-dependent ground motions and with the use of composite spectra obtained from the current library of strong motion records. Recommended procedures for defining vibratory ground motion criteria contain the following steps: (1) geologic and seismologic studies; (2) site soils investigations; (3) site response sensitivity studies; (4) evaluation of local site response characteristics; (5) selection of site-matched records; and (6) appraisal and selection of seismic input criteria. An in-depth discussion of the engineering characteristics of earthquake ground motions including parameters used to characterize earthquakes and strong motion records, geologic factors that influence ground shaking, the current strong motion data base, and case histories of the effects of past earthquake events is presented. Next, geotechnical investigations of the seismologic, geologic, and site soil conditions required to develop vibratory motion criteria are briefly summarized. The current technology for establishing vibratory ground motion criteria at nuclear plant sites, including site-independent and site-dependent procedures that use data from strong motion records and from soil response analyses is described. (auth)

  5. Nuclear spectroscopy and quantum chaos

    International Nuclear Information System (INIS)

    Sakata, Fumihiko; Marumori, Toshio; Hashimoto, Yukio; Yamamoto, Yoshifumi; Tsukuma, Hidehiko; Iwasawa, Kazuo.

    1990-05-01

    In this paper, a recent development of INS-TSUKUBA joint research project on large-amplitude collective motion is summerized. The classical theory of nuclear collective dynamics formulated within the time-dependent Hartree-Fock theory is recapitulated and decisive role of the level crossing in the single-particle dynamics on the order-to-chaos transition of collective motion is discussed in detail. Extending the basic idea of the classical theory, we discuss a quantum theory of nuclear collective dynamics which allows us to properly define a concept of quantum chaos for each eigenfunction. By using numerical calculation, we illustrate what the quantum chaos for each eigenfunction means and its relation to usual definition based on the random matrix theory. (author)

  6. Theory of collective Hamiltonian

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qingying

    1982-02-01

    Starting from the cranking model, we derive the nuclear collective Hamiltonian. We expand the total energy of the collective motion of the ground state of even--even nuclei in powers of the deformation parameter ..beta... In the first approximation, we only take the lowest-order non-vanished terms in the expansion. The collective Hamiltonian thus obtained rather differs from the A. Bohr's Hamiltonian obtained by the irrotational incompressible liquid drop model. If we neglect the coupling term between ..beta..-and ..gamma..-vibration, our Hamiltonian then has the same form as that of A. Bohr. But there is a difference between these collective parameters. Our collective parameters are determined by the state of motion of the nucleous in the nuclei. They are the microscopic expressions. On the contrary, A. Bohr's collective parameters are only the simple functions of the microscopic physical quantities (such as nuclear radius and surface tension, etc.), and independent of the state of motion of the nucleons in the nuclei. Furthermore, there exist the coupling term between ..beta..-and ..gamma..-vibration and the higher-order terms in our expansion. They can be treated as the perturbations. There are no such terms in A. Bohr's Hamiltonian. These perturbation terms will influence the rotational, vibrational spectra and the ..gamma..-transition process, etc.

  7. From schooling to shoaling: patterns of collective motion in zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Noam Miller

    Full Text Available Animal groups on the move can take different configurations. For example, groups of fish can either be 'shoals' or 'schools': shoals are simply aggregations of individuals; schools are shoals exhibiting polarized, synchronized motion. Here we demonstrate that polarization distributions of groups of zebrafish (Danio rerio are bimodal, showing two distinct modes of collective motion corresponding to the definitions of shoaling and schooling. Other features of the group's motion also vary consistently between the two modes: zebrafish schools are faster and less dense than zebrafish shoals. Habituation to an environment can also alter the proportion of time zebrafish groups spend schooling or shoaling. Models of collective motion suggest that the degree and stability of group polarization increases with the group's density. Examining zebrafish groups of different sizes from 5 to 50, we show that larger groups are less polarized than smaller groups. Decreased fearfulness in larger groups may function similarly to habituation, causing them to spend more time shoaling than schooling, contrary to most models' predictions.

  8. Microscopic collective models of nuclei

    International Nuclear Information System (INIS)

    Lovas, Rezsoe

    1985-01-01

    Microscopic Rosensteel-Rowe theory of the nuclear collective motion is described. The theoretical insufficiency of the usual microscopic establishment of the collective model is pointed. The new model treating exactly the degrees of freedom separates the coordinates describing the collective motion and the internal coordinates by a consistent way. Group theoretical methods analyzing the symmetry properties of the total Hamiltonian are used defining the collective subspaces transforming as irreducible representations of the group formed by the collective operators. Recent calculations show that although the results of the usual collective model are approximately correct and similar to those of the new microscopic collective model, the underlying philosophy of the old model is essentially erroneous. (D.Gy.)

  9. Analytic model for surface ground motion with spall induced by underground nuclear tests

    International Nuclear Information System (INIS)

    MacQueen, D.H.

    1982-04-01

    This report provides a detailed presentation and critique of a model used to characterize the surface ground motion following a contained, spalling underground nuclear explosion intended for calculation of the resulting atmospheric acoustic pulse. Some examples of its use are included. Some discussion of the general approach of ground motion model parameter extraction, not dependent on the specific model, is also presented

  10. Fundamentals of nuclear physics

    International Nuclear Information System (INIS)

    Jelley, N.A.

    1990-01-01

    The book is aimed at undergraduates in their final year, to give the student a thorough understanding of the principal features of nuclei, nuclear decays and nuclear reactions. Several models are described and used to explain nuclear properties with many illustrative examples. Sections follow on α-, β- and γ-decay, fission, thermonuclear fusion, reactions, nuclear forces and nuclear collective motion. (author)

  11. Nuclear moments of inertia and wobbling motions in triaxial superdeformed nuclei

    International Nuclear Information System (INIS)

    Matsuzaki, Masayuki; Shimizu, Yoshifumi R.; Matsuyanagi, Kenichi

    2004-01-01

    The wobbling motion excited on triaxial superdeformed nuclei is studied in terms of the cranked shell model plus random phase approximation. First, by calculating at a low rotational frequency the γ dependence of the three moments of inertia associated with the wobbling motion, the mechanism of the appearance of the wobbling motion in positive-γ nuclei is clarified theoretically--the rotational alignment of the πi 13/2 quasiparticle(s) is the essential condition. This indicates that the wobbling motion is a collective motion that is sensitive to the single-particle alignment. Second, we prove that the observed unexpected rotational-frequency dependence of the wobbling frequency is an outcome of the rotational-frequency dependent dynamical moments of inertia

  12. An adiabatic time-dependent Hartree-Fock theory of collective motion in finite systems

    International Nuclear Information System (INIS)

    Baranger, M.; Veneroni, M.

    1977-11-01

    It is shown how to derive the parameters of a phenomenological collective model from a microscopic theory. The microscopic theory is Hartree-Fock, and one starts from the time-dependent Hartree-Fock equation. To this, the adiabatic approximation is added, and the energy in powers of an adiabatic parameter is expanded, which results in a collective kinetic energy quadratic in the velocities, with coefficients depending on the coordinates, as in the phenomenological models. The adiabatic equations of motion are derived in different ways and their analogy with classical mechanics is stressed. The role of the adiabatic hypothesis and its range of validity, are analyzed in detail. It assumes slow motion, but not small amplitude, and is therefore suitable for large-amplitude collective motion. The RPA is obtained as the limiting case where the amplitude is also small. The translational mass is correctly given and the moment of inertia under rotation is that of Thouless and Valatin

  13. Nuclear structure

    International Nuclear Information System (INIS)

    Eastham, D.A.; Joy, T.

    1986-01-01

    The paper on 'nuclear structure' is the Appendix to the Daresbury (United Kingdom) Annual Report 1985/86, and contains the research work carried out at the Nuclear Structure Facility, Daresbury, within that period. During the year a total of 74 experiments were scheduled covering the main areas of activity including: nuclear collective motion, nuclei far from stability, and nuclear collisions. The Appendix contains brief reports on these experiments and associated theory. (U.K.)

  14. Evaluation of vibratory ground motion at nuclear power plant sites

    International Nuclear Information System (INIS)

    Hofmann, R.B.; Greeves, J.T.

    1978-01-01

    The evaluation of vibratory ground motion at nuclear power plant sites requires the cooperative effort of scientists and engineers in several disciplines. These include seismology, geology, geotechnical engineering and structural engineering. The Geosciences Branch of the NRC Division of Site Safety and Environmental Analysis includes two sections, the Geology/Seismology Section and the Geotechnical Engineering Section

  15. Reflections on collectivity

    International Nuclear Information System (INIS)

    Feshbach, H.

    1983-01-01

    Comments are made on papers presented to the International School of Nuclear Physics, Erice (1982) concerning collective bands and collectivity in nuclei. The importance of these collective modes of motion, the role of the Bohr-Mottelson model and the Interacting Boson Models (IBM-1 and IBM-2), and experimental evidence presented by a number of workers, are examined. The extensions of the models to take into account additional degrees of freedom both collective and non-collective, the discovery of new collective modes such as those corresponding to tri-axial shapes, and the possible existence of additional symmetries reported at the meeting, are discussed. Finally the importance is examined of relating the phenomenological models to a more fundamental underlying theory, which has been taken to be the nuclear shell model. (U.K.)

  16. Nuclear quantum many-body dynamics: from collective vibrations to heavy-ion collisions

    International Nuclear Information System (INIS)

    Simenel, Cedric

    2012-01-01

    This report gives a summary of my research on nuclear dynamics during the past ten years. The choice of this field has been motivated by the desire to understand the physics of complex systems obeying quantum mechanics. In particular, the interplay between collective motion and single-particle degrees of freedom is a source of complex and fascinating behaviours. For instance, giant resonances are characterised by a collective vibration of many nucleons, but their decay may occur by the emission of a single nucleon. Another example could be taken from the collision of nuclei where the transfer of few nucleons may have a strong impact on the formation of a compound system is non trivial. To describe these complex systems, one needs to solve the quantum many-body problem. The description of the dynamics of composite systems can be very challenging, especially when two such systems interact. An important goal of nuclear physics is to find a unified way to describe the dynamics of nuclear systems. Ultimately, the same theoretical model should be able to describe vibrations, rotations, fission, all the possible outcomes of heavy-ion collisions (elastic and inelastic scattering, particle transfer, fusion, and multifragmentation), and even the dynamics of neutron star crust. This desire for a global approach to nuclear dynamics has strongly influenced my research activities. In particular, all the numerical applications presented in this report have been obtained from few numerical codes solving equations derived from the same variational principle. Beside the quest for a unified model of nuclear dynamics, possible applications of heavy-ion collisions such as the formation of new nuclei is also a strong motivation for the experimental and theoretical studies of reaction mechanisms. This report is not a review article, but should be considered as a reading guide of the main papers my collaborators and myself have published. It also gives the opportunity to detail some

  17. Joint motion clusters in servomanipulator operation

    International Nuclear Information System (INIS)

    Draper, J.V.; Sundstrom, E.; Herndon, J.N.

    1986-01-01

    The Consolidated Fuel Reprocessing Program (CFRP) at the Oak Ridge National Laboratory is developing advanced teleoperator systems for maintenance of future nuclear fuel reprocessing facilities. Remote maintenance systems developed by the CFRP emphasize man-in-the-loop teleoperation. This paper reports the results of a recent experiment which investigated how users interact with a multi-degree-of-freedom servomanipulator. Principal components analysis performed on data collected during completion of typical remote maintenance tests indicates that joint motions may be summarized by two orthogonal clusters, one which represents fine-adjusting motions and one which represents slewing motions. Implications of these findings for servomanipulator design are discussed. 5 refs., 1 fig., 2 tabs

  18. Dynamics of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1979-01-01

    Large-amplitude collective motion in fission and heavy-ion reactions is studied by solving classical equations of motion for the time evolution of the nuclear shape. In the nuclear potential energy of deformation, the generalized surface energy was calculated by means of a double volume integral of a Yukawa-plus-exponential function, which was obtained by requiring that two semi-infinite slabs of constant-density nuclear matter have minimum energy at zero separation. The collective kinetic energy is calculated for nuclear flow that is a superposition of incompressible, nearly irrotational collective-shape motion and rigid-body rotation. Nuclear dissipation is included by means of the Rayleigh dissipation function, which depends upon the physical mechanism that converts collective energy into internal energy. For both ordinary two-body viscosity and a combined wall and window one-body dissipation, fission-fragment kinetic energies are calculated for the fission of nuclei throughout the periodic table and compare with experimental results. Finally, the one-body dynamics of nucleons inside a cylinder colliding with a moving piston is explicitly studied by solving exactly the collisionless Boltzmann equation for the distribution function. By examining the relative phases of the pressure at the piston and the piston's velocity, a dissipative force and an elastic restoring force can be separately identified. 9 references

  19. Automatic motion inhibit system for a nuclear power generating system

    International Nuclear Information System (INIS)

    Musick, C.R.; Torres, J.M.

    1977-01-01

    Disclosed is an automatic motion inhibit system for a nuclear power generating system for inhibiting automatic motion of the control elements to reduce reactor power in response to a turbine load reduction. The system generates a final reactor power level setpoint signal which is continuously compared with a reactor power signal. The final reactor power level setpoint is a setpoint within the capacity of the bypass valves to bypass steam which in no event is lower in value than the lower limit of automatic control of the reactor. If the final reactor power level setpoint is greater than the reactor power, an inhibit signal is generated to inhibit automatic control of the reactor. 6 claims, 5 figures

  20. Selected topics in nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Solov` ev, V G; Gromov, K Ya; Malov, L A; Shilov, V M

    1994-12-31

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles). heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and {beta}-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei.

  1. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Solov'ev, V.G.; Gromov, K.Ya.; Malov, L.A.; Shilov, V.M.

    1994-01-01

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  2. Comparison of the inelastic response of steel building frames to strong earthquake and underground nuclear explosion ground motion

    International Nuclear Information System (INIS)

    Murray, R.C.; Tokarz, F.J.

    1976-01-01

    Analytic studies were made of the adequacy of simulating earthquake effects at the Nevada Test Site for structural testing purposes. It is concluded that underground nuclear explosion ground motion will produce inelastic behavior and damage comparable to that produced by strong earthquakes. The generally longer duration of earthquakes compared with underground nuclear explosions does not appear to significantly affect the structural behavior of the building frames considered. A comparison of maximum ductility ratios, maximum story drifts, and maximum displacement indicate similar structural behavior for both types of ground motion. Low yield (10 - kt) underground nuclear explosions are capable of producing inelastic behavior in large structures. Ground motion produced by underground nuclear explosions can produce inelastic earthquake-like effects in large structures and could be used for testing large structures in the inelastic response regime. The Nevada Test Site is a feasible earthquake simulator for testing large structures

  3. Two-fluid equations for a nuclear system with arbitrary motions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Jae [Chungnam National University, Daejeon (Korea, Republic of); Kim, Kyung Doo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Ocean nuclear systems include a seabed-type plant, a floating-type plant, and a nuclear-propulsion ship. We asked ourselves, 'What governing equations should be used for ocean nuclear systems?' Since ocean nuclear systems are apt to move arbitrarily, the two-fluid model must be formulated in the non-inertial frame of reference that is undergoing acceleration with respect to an inertial frame. Two-phase flow systems with arbitrary motions are barely reported. Kim et al. (1996) added the centripetal and Euler acceleration forces to the homogeneous equilibrium momentum equation embedded in the RETRAN code. However, they did not look into the mass and energy equations. The purpose of this study is to derive general two-fluid equations in the non-inertial frame of reference, which can be used for safety analysis of ocean nuclear systems. The two-fluid equation forms for scalar properties such as mass, internal energy, and enthalpy equation in the moving frame are the same as those in the absolute frame. On the other hand, the fictitious effect must be included in the momentum equation.

  4. Collective dose commitments from nuclear power programmes

    International Nuclear Information System (INIS)

    Beninson, D.

    1977-01-01

    The concepts of collective dose and collective dose commitment are discussed, particularly regarding their use to compare the relative importance of the exposure from several radiation sources and to predict future annual doses from a continuing practice. The collective dose commitment contributions from occupational exposure and population exposure due to the different components of the nuclear power fuel cycle are evaluated. A special discussion is devoted to exposures delivered over a very long time by released radionuclides of long half-lives and to the use of the incomplete collective dose commitment. The maximum future annual ''per caput'' doses from present and projected nuclear power programmes are estimated

  5. Ground motion predictions

    Energy Technology Data Exchange (ETDEWEB)

    Loux, P C [Environmental Research Corporation, Alexandria, VA (United States)

    1969-07-01

    Nuclear generated ground motion is defined and then related to the physical parameters that cause it. Techniques employed for prediction of ground motion peak amplitude, frequency spectra and response spectra are explored, with initial emphasis on the analysis of data collected at the Nevada Test Site (NTS). NTS postshot measurements are compared with pre-shot predictions. Applicability of these techniques to new areas, for example, Plowshare sites, must be questioned. Fortunately, the Atomic Energy Commission is sponsoring complementary studies to improve prediction capabilities primarily in new locations outside the NTS region. Some of these are discussed in the light of anomalous seismic behavior, and comparisons are given showing theoretical versus experimental results. In conclusion, current ground motion prediction techniques are applied to events off the NTS. Predictions are compared with measurements for the event Faultless and for the Plowshare events, Gasbuggy, Cabriolet, and Buggy I. (author)

  6. Ground motion predictions

    International Nuclear Information System (INIS)

    Loux, P.C.

    1969-01-01

    Nuclear generated ground motion is defined and then related to the physical parameters that cause it. Techniques employed for prediction of ground motion peak amplitude, frequency spectra and response spectra are explored, with initial emphasis on the analysis of data collected at the Nevada Test Site (NTS). NTS postshot measurements are compared with pre-shot predictions. Applicability of these techniques to new areas, for example, Plowshare sites, must be questioned. Fortunately, the Atomic Energy Commission is sponsoring complementary studies to improve prediction capabilities primarily in new locations outside the NTS region. Some of these are discussed in the light of anomalous seismic behavior, and comparisons are given showing theoretical versus experimental results. In conclusion, current ground motion prediction techniques are applied to events off the NTS. Predictions are compared with measurements for the event Faultless and for the Plowshare events, Gasbuggy, Cabriolet, and Buggy I. (author)

  7. Precession mode on high-K configurations: non-collective axially-symmetric limit of wobbling motion

    International Nuclear Information System (INIS)

    Shimizu, Yoshifumi R; Matsuzaki, Masayuki; Matsuyanagi, Kenichi

    2006-01-01

    The precession mode, the rotational excitation built on the high-K isomeric state, in comparison with the recently identified wobbling mode has been studied. The random-phase-approximation (RPA) formalism, which has been developed for the nuclear wobbling motion, is invoked and the precession phonon is obtained by the non-collective axially symmetric limit of the formalism. The excitation energies and the electromagnetic properties of the precession bands in 178 W are calculated, and it is found that the results of RPA calculations well correspond to those of the rotor model; the correspondence can be understood by an adiabatic approximation to the RPA phonon. As a by-product, it is also found that the problem of too small out-of-band B(E2) in our previous RPA wobbling calculations can be solved by a suitable choice of the triaxial deformation which corresponds to the one used in the rotor model

  8. Coded aperture imaging system for nuclear fuel motion detection

    International Nuclear Information System (INIS)

    Stalker, K.T.; Kelly, J.G.

    1980-01-01

    A Coded Aperature Imaging System (CAIS) has been developed at Sandia National Laboratories to image the motion of nuclear fuel rods undergoing tests simulating accident conditions within a liquid metal fast breeder reactor. The tests require that the motion of the test fuel be monitored while it is immersed in a liquid sodium coolant precluding the use of normal optical means of imaging. However, using the fission gamma rays emitted by the fuel itself and coded aperture techniques, images with 1.5 mm radial and 5 mm axial resolution have been attained. Using an electro-optical detection system coupled to a high speed motion picture camera a time resolution of one millisecond can be achieved. This paper will discuss the application of coded aperture imaging to the problem, including the design of the one-dimensional Fresnel zone plate apertures used and the special problems arising from the reactor environment and use of high energy gamma ray photons to form the coded image. Also to be discussed will be the reconstruction techniques employed and the effect of various noise sources on system performance. Finally, some experimental results obtained using the system will be presented

  9. Variational principles for collective motion: Relation between invariance principle of the Schroedinger equation and the trace variational principle

    International Nuclear Information System (INIS)

    Klein, A.; Tanabe, K.

    1984-01-01

    The invariance principle of the Schroedinger equation provides a basis for theories of collective motion with the help of the time-dependent variational principle. It is formulated here with maximum generality, requiring only the motion of intrinsic state in the collective space. Special cases arise when the trial vector is a generalized coherent state and when it is a uniform superposition of collective eigenstates. The latter example yields variational principles uncovered previously only within the framework of the equations of motion method. (orig.)

  10. Microscopic nuclear dissipation. Pt. 2

    International Nuclear Information System (INIS)

    Yannouleas, C.; Dworzecka, M.; Griffin, J.J.

    1983-01-01

    We have formulated a microscopic, nonperturbative, time reversible model which exhibits a dissipative decay of collective motion for times short compared to the system's Poincare time. The model assumes an RPA approximate description of the initial collective state within a restricted subspace, then traces its time evolution when an additional subspace is coupled to the restricted subspace by certain simplified matrix elements. It invokes no statistical assumptions. The damping of the collective motion occurs via real transitions from the collective state to other more complicated nuclear states of the same energy. It corresponds therefore to the so called 'one-body' long mean free path limit of nuclear dissipation when the collective state describes a surface vibration. When the simplest RPA approximation is used, this process associates the dissipation with the escape width for direct particle emission to the continuum. When the more detailed second RPA is used, it associates the dissipation with the spreading width for transitions to the 2p-2h components of the nuclear compound states as well. The energy loss rate for sharp n-phonon initial states is proportional to the total collective energy, unlike the dissipation of a classical damped oscillator, where it is proportional to the kinetic energy only. However, for coherent, multi-phonon wave packets, which explicitly describe the time-dependent oscillations of the mean field, dissipation proportional only to the kinetic energy is obtained. Canonical coordinates for the collective degree of freedom are explicitly introduced and a nonlinear frictional hamiltonian to describe such systems is specified by the requirement that it yield the same time dependence for the collective motion as the microscopic model. Thus, for the first time a descriptive nonlinear hamiltonian is derived explicitly from the underlying microscopic model of a nuclear system. (orig.)

  11. Collective circular motion in synchronized and balanced formations with second-order rotational dynamics

    Science.gov (United States)

    Jain, Anoop; Ghose, Debasish

    2018-01-01

    This paper considers collective circular motion of multi-agent systems in which all the agents are required to traverse different circles or a common circle at a prescribed angular velocity. It is required to achieve these collective motions with the heading angles of the agents synchronized or balanced. In synchronization, the agents and their centroid have a common velocity direction, while in balancing, the movement of agents causes the location of the centroid to become stationary. The agents are initially considered to move at unit speed around individual circles at different angular velocities. It is assumed that the agents are subjected to limited communication constraints, and exchange relative information according to a time-invariant undirected graph. We present suitable feedback control laws for each of these motion coordination tasks by considering a second-order rotational dynamics of the agent. Simulations are given to illustrate the theoretical findings.

  12. Skyrme's interaction beyond the mean-field. The DGCM+GOA Hamiltonian of nuclear quadrupole motion

    International Nuclear Information System (INIS)

    Kluepfel, Peter

    2008-01-01

    This work focuses on the microscopic description of nuclear collective quadrupole motion within the framework of the dynamic Generator-Coordinate-Method(DGCM)+Gaussian-Overlap-Approximation(GOA). Skyrme-type effective interactions are used as the fundamental many-particle interaction. Starting from a rotational invariant, polynomial and topologic consistent formulation of the GCM+GOA Hamiltonian an interpolation scheme for the collective masses and potential is developed. It allows to define the collective Hamiltonian of fully triaxial collective quadrupole dynamics from a purely axial symmetric configuration space. The substantial gain in performance allows the self-consistent evaluation of the dynamic quadrupole mass within the ATDHF-cranking model. This work presents the first large-scale analysis of quadrupole correlation energies and lowlying collective states within the DGCM+GOA model. Different Skyrme- and pairing interactions are compared from old standards up to more recent parameterizations. After checking the validity of several approximations to the DGCM+GOA model - both on the mean-field and the collective level - we proceed with a detailed investigation of correlation effects along the chains of semi-magic isotopes and isotones. This finally allows to define a set of observables which are hardly affected by collective correlations. Those observables were used for a refit of a Skyrme-type effective interaction which is expected to cure most of the problems of the recent parameterizations. Preparing further work, estimates for the correlated ground state energy are proposed which can be evaluated directly from the mean-field model. (orig.)

  13. Skyrme's interaction beyond the mean-field. The DGCM+GOA Hamiltonian of nuclear quadrupole motion

    Energy Technology Data Exchange (ETDEWEB)

    Kluepfel, Peter

    2008-07-29

    This work focuses on the microscopic description of nuclear collective quadrupole motion within the framework of the dynamic Generator-Coordinate-Method(DGCM)+Gaussian-Overlap-Approximation(GOA). Skyrme-type effective interactions are used as the fundamental many-particle interaction. Starting from a rotational invariant, polynomial and topologic consistent formulation of the GCM+GOA Hamiltonian an interpolation scheme for the collective masses and potential is developed. It allows to define the collective Hamiltonian of fully triaxial collective quadrupole dynamics from a purely axial symmetric configuration space. The substantial gain in performance allows the self-consistent evaluation of the dynamic quadrupole mass within the ATDHF-cranking model. This work presents the first large-scale analysis of quadrupole correlation energies and lowlying collective states within the DGCM+GOA model. Different Skyrme- and pairing interactions are compared from old standards up to more recent parameterizations. After checking the validity of several approximations to the DGCM+GOA model - both on the mean-field and the collective level - we proceed with a detailed investigation of correlation effects along the chains of semi-magic isotopes and isotones. This finally allows to define a set of observables which are hardly affected by collective correlations. Those observables were used for a refit of a Skyrme-type effective interaction which is expected to cure most of the problems of the recent parameterizations. Preparing further work, estimates for the correlated ground state energy are proposed which can be evaluated directly from the mean-field model. (orig.)

  14. Consistent microscopic theory of collective motion in the framework of an ATDHF approach

    International Nuclear Information System (INIS)

    Goeke, K.; Reinhard, P.

    1978-01-01

    Based on merely two assumptions, namely the existence of a collective Hamiltonian and that the collective motion evolves along Slater determinants, we first derive a set of adiabatic time-dependent Hartree-Fock equations (ATDHF) which determine the collective path, the mass and the potential, second give a unique procedure for quantizing the resulting classical collective Hamiltonian, and third explain how to use the collective wavefunctions, which are eigenstates of the quantized Hamiltonian

  15. Oscillating molecular dipoles require strongly correlated electronic and nuclear motion

    International Nuclear Information System (INIS)

    Chang, Bo Y; Shin, Seokmin; Palacios, Alicia; Martín, Fernando; Sola, Ignacio R

    2015-01-01

    To create an oscillating electric dipole in an homonuclear diatomic cation without an oscillating driver one needs (i) to break the symmetry of the system and (ii) to sustain highly correlated electronic and nuclear motion. Based on numerical simulations in H 2 + we present results for two schemes. In the first one (i) is achieved by creating a superposition of symmetric and antisymmetric electronic states freely evolving, while (ii) fails. In a second scheme, by preparing the system in a dressed state of a strong static field, both conditions hold. We then analyze the robustness of this scheme with respect to features of the nuclear wave function and its intrinsic sources of decoherence. (tutorial)

  16. Collective spin by linearization of the Schrodinger equation for nuclear collective motion

    International Nuclear Information System (INIS)

    Greiner, M.; Scheid, W.; Herrmann, R.

    1988-01-01

    The free Schrodinger equation for multipole degrees of freedom is linearized so that energy and momentum operators appear only in first order. As an example, the authors demonstrate the linearization procedure for quadrupole degrees of freedom. The wave function solving this equation carries a spin. The authors derive the operator of the collective spin and its eigen values depending on multipolarity

  17. Consecutive collection of new finding and knowledge on science and technology to be reflected to seismic safety assessment for nuclear facilities

    International Nuclear Information System (INIS)

    Tsutsumi, Hideaki; Iijima, Toru

    2013-05-01

    JNES had been collecting and analyzing new finding and knowledge on science and technology to be reflected to seismic safety assessment for nuclear facilities, which was updated so as to develop a system to organize and disseminate such information in response to Nuclear Regulation Authority (NRA)'s policy on new safety regulations requesting enhanced protective measures against extreme natural hazards. The tasks were as follows; (1) collection of new finding and knowledge from seismic safety research of JNES, (2) constructing database of seismic safety research from documents published by committees and including the Great East Japan Earthquake and (3) dissemination of information related to seismic research. As for JFY 2012 activities, collecting and analyzing new finding and knowledge were on three areas such as active fault, seismic source/ground motion and tsunami. 4 theme related with the Great East Japan Earthquake, 7 items not related with the Great East Japan Earthquake and one item on external event were collected and analyzed whether incorporating in seismic safety research important for regulation to increase seismic safety of nuclear facilities, with no such theme confirmed. (T. Tanaka)

  18. Pedestrian collective motion in competitive room evacuation.

    Science.gov (United States)

    Garcimartín, A; Pastor, J M; Martín-Gómez, C; Parisi, D; Zuriguel, I

    2017-09-07

    When a sizable number of people evacuate a room, if the door is not large enough, an accumulation of pedestrians in front of the exit may take place. This is the cause of emerging collective phenomena where the density is believed to be the key variable determining the pedestrian dynamics. Here, we show that when sustained contact among the individuals exists, density is not enough to describe the evacuation, and propose that at least another variable -such as the kinetic stress- is required. We recorded evacuation drills with different degrees of competitiveness where the individuals are allowed to moderately push each other in their way out. We obtain the density, velocity and kinetic stress fields over time, showing that competitiveness strongly affects them and evidencing patterns which have been never observed in previous (low pressure) evacuation experiments. For the highest competitiveness scenario, we detect the development of sudden collective motions. These movements are related to a notable increase of the kinetic stress and a reduction of the velocity towards the door, but do not depend on the density.

  19. Prediction of seismic motion from contained and excavation nuclear detonations

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R A [Environmental Research Corp., Alexandria, VA (United States)

    1970-05-15

    Capability to predict ground motions from nuclear events is developed on empirical and theoretical bases. Analyses of the experimental data provide basic predictions of peak particle motions and spectra which follow a (yield){sup m} times (distance){sup -n} relationship. The exponents on yield and distance are frequency dependent and derived from experiment and theory. Theory provides a physical understanding of the phenomena which allows extrapolation to off-NTS and atypical events. For example, yield scaling theory predicts significantly higher frequency motions and consequently larger ground accelerations for overburied events such as Gasbuggy, Rulison, Wasp and Wagon Wheel. These conclusions are observed from Gasbuggy (26 kt) which generated ground accelerations comparable to a normal buried event of 200 kt. This result is important in avoiding personal injury and assessing the probability of property damage. Conversely, theory predicts lower ground accelerations and seismic efficiencies for excavation events; these effects are observed from the Cabriolet and Schooner events and consequently predicted for the Sturtevant and Yawl events. With regard to the distance exponent, scattering theory determines a distance exponent which predicts greater attenuation effects on higher frequency motions. This trend is verified experimentally by regression analyses on a large number of data points which determine the distance exponent to range from -1.1 at low frequencies to -1.6 at high frequencies. Results indicate that cube root similarity scaling is not appropriate in the far field except possibly for peak particle displacements at the low frequency end of the spectrum. In addition to the source and transmission factors, current ground motion prediction techniques, on and off-NTS, take into account local site characteristics. Experimental evidence and theoretical models--layered media elastic theory, finite element modeling, and building response modeling

  20. Collective motions and non-polynomial lagrangians in Fokker-Planck dynamics

    International Nuclear Information System (INIS)

    Spina, A.; Vucetich, H.

    1986-04-01

    A method based on the ideas of collective motion is applied to Fokker-Planck dynamics. The usual diagramatic techniques used in stochastic dynamics are enlarged in order to deal with the non-polynomial Lagrangians that appear in the theory. The technique is tested and applied to the case of a self-sustained sinusoidal oscillator whose statistical behaviour is well understood: the Poincare oscillator. (author)

  1. Physical aspects of nuclear ventriculography

    International Nuclear Information System (INIS)

    Alpert, N.M.; Chesler, D.A.; Burnham, C.A.; McKusick, K.A.; Pohost, G.; Dinsmore, R.E.; Brownell, G.L.

    1976-01-01

    The use of edge enhancement and computer motion display improves the detection of regional wall motion abnormalities in the LV. Improved gating and processing techniques should improve the accuracy of ventricular volume vs time measurements. It is hoped that the simulations described will aid in the development of new instrumentation for the collection and analysis of nuclear ventriculographie data

  2. Exploring the onset of collective motion in self-organised trails of social organisms

    Science.gov (United States)

    Brigatti, E.; Hernández, A.

    2018-04-01

    We investigate the emergence of self-organised trails between two specific target areas in collective motion of social organisms by means of an agent-based model. We present numerical evidences that an increase in the efficiency of navigation, in dependence of the colony size, exists. Moreover, the shift, from the diffusive to the directed motion can be quantitatively characterised, identifying and measuring a well defined crossover point. This point corresponds to the minimal number of individuals necessary for the onset of collective cooperation. Finally, by means of a finite-size scaling analysis, we describe its scaling behaviour as a function of the environment size. This last result can be of particular interest for interpreting empirical observations or for the design of artificial swarms.

  3. How to: Using Mode Analysis to Quantify, Analyze, and Interpret the Mechanisms of High-Density Collective Motion

    Directory of Open Access Journals (Sweden)

    Arianna Bottinelli

    2017-12-01

    Full Text Available While methods from statistical mechanics were some of the earliest analytical tools used to understand collective motion, the field has substantially expanded in scope beyond phase transitions and fluctuating order parameters. In part, this expansion is driven by the increasing variety of systems being studied, which in turn, has increased the need for innovative approaches to quantify, analyze, and interpret a growing zoology of collective behaviors. For example, concepts from material science become particularly relevant when considering the collective motion that emerges at high densities. Here, we describe methods originally developed to study inert jammed granular materials that have been borrowed and adapted to study dense aggregates of active particles. This analysis is particularly useful because it projects difficult-to-analyze patterns of collective motion onto an easier-to-interpret set of eigenmodes. Carefully viewed in the context of non-equilibrium systems, mode analysis identifies hidden long-range motions and localized particle rearrangements based solely on the knowledge of particle trajectories. In this work, we take a “how to” approach and outline essential steps, diagnostics, and know-how used to apply this analysis to study densely-packed active systems.

  4. Origin of inertia in large-amplitude collective motion in finite Fermi ...

    Indian Academy of Sciences (India)

    There is a tacit assumption that the collective variables (shape) determine the internal structure and state of the nucleus. A detailed derivation of eq. (2) based on the principle of least action is given in [16]. During collec- tive motion, the eigenstate does not change leading thereby to adiabatic approximation, and we shall ...

  5. Collective Motion of Micro-organisms from Field Theoretical Viewpoint

    OpenAIRE

    Nojiri, Shin'ichi; Kawamura, Masako; Sugamoto, Akio

    1995-01-01

    We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro- organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide ...

  6. Collective cell motion in endothelial monolayers

    International Nuclear Information System (INIS)

    Szabó, A; Ünnep, R; Méhes, E; Czirók, A; Twal, W O; Argraves, W S; Cao, Y

    2010-01-01

    Collective cell motility is an important aspect of several developmental and pathophysiological processes. Despite its importance, the mechanisms that allow cells to be both motile and adhere to one another are poorly understood. In this study we establish statistical properties of the random streaming behavior of endothelial monolayer cultures. To understand the reported empirical findings, we expand the widely used cellular Potts model to include active cell motility. For spontaneous directed motility we assume a positive feedback between cell displacements and cell polarity. The resulting model is studied with computer simulations and is shown to exhibit behavior compatible with experimental findings. In particular, in monolayer cultures both the speed and persistence of cell motion decreases, transient cell chains move together as groups and velocity correlations extend over several cell diameters. As active cell motility is ubiquitous both in vitro and in vivo, our model is expected to be a generally applicable representation of cellular behavior

  7. Collective dynamics of nuclear fusion: deformation changes and heating during the fusion

    International Nuclear Information System (INIS)

    Mikhailov, I.N.; Mikhailova, T.I.; Toro, M. di; Baran, V.; Briancon, C.

    1996-01-01

    The formalism developed elsewhere for the theoretical description of the dynamics involved in the heavy nucleus fusion is applied in this paper to study the history of the fusion of two identical heavy nuclei experiencing central collision. The evolution of the shape and of the temperature of symmetrical fusing systems is studied. The role of the elastoplasticity of nuclear matter in the nonmonotonical changes of the shape is elucidated in this way. A tentative explanation of the ''extra push'' phenomenon is given in terms of the competition between elastic properties of fusing systems driving to the re-separation of colliding nuclei and the dissipative (plastic) properties of nuclear matter transforming the energy of collective motion into the energy of statistical excitation and thus leading to the fusion. The fingerprints of the heavy-nucleus fusion history as it is depicted by the model are traced in the anisotropy of the dipole and quadrupole γ-radiation emitted during the fusion. The parallels in the description of the fusion dynamics given by the simple model used in this paper and by the more fundamental approaches based on the kinetic equation are emphasised. (orig.)

  8. Toward the fundamental theory of nuclear matter physics: The microscopic theory of nuclear collective dynamics

    International Nuclear Information System (INIS)

    Sakata, F.; Marumori, T.; Hashimoto, Y.; Tsukuma, H.; Yamamoto, Y.; Terasaki, J.; Iwasawa, Y.; Itabashi, H.

    1992-01-01

    Since the research field of nuclear physics is expanding rapidly, it is becoming more imperative to develop the microscopie theory of nuclear matter physics which provides us with a unified understanding of diverse phenomena exhibited by nuclei. An estabishment of various stable mean-fields in nuclei allows us to develop the microscopie theory of nuclear collective dynamics within the mean-field approximation. The classical-level theory of nuclear collective dynamics is developed by exploiting the symplectic structure of the timedependent Hartree-Fock (TDHF)-manifold. The importance of exploring the single-particle dynamics, e.g. the level-crossing dynamics in connection with the classical order-to-chaos transition mechanism is pointed out. Since the classical-level theory os directly related to the full quantum mechanical boson expansion theory via the symplectic structure of the TDHF-manifold, the quantum theory of nuclear collective dynamics is developed at the dictation of what os developed on the classical-level theory. The quantum theory thus formulated enables us to introduce the quantum integrability and quantum chaoticity for individual eigenstates. The inter-relationship between the classical-level and quantum theories of nuclear collective dynamics might play a decisive role in developing the quantum theory of many-body problems. (orig.)

  9. Seismic Hazard Assessment in Site Evaluation for Nuclear Installations: Ground Motion Prediction Equations and Site Response

    International Nuclear Information System (INIS)

    2016-07-01

    The objective of this publication is to provide the state-of-the-art practice and detailed technical elements related to ground motion evaluation by ground motion prediction equations (GMPEs) and site response in the context of seismic hazard assessments as recommended in IAEA Safety Standards Series No. SSG-9, Seismic Hazards in Site Evaluation for Nuclear Installations. The publication includes the basics of GMPEs, ground motion simulation, selection and adjustment of GMPEs, site characterization, and modelling of site response in order to improve seismic hazard assessment. The text aims at delineating the most important aspects of these topics (including current practices, criticalities and open problems) within a coherent framework. In particular, attention has been devoted to filling conceptual gaps. It is written as a reference text for trained users who are responsible for planning preparatory seismic hazard analyses for siting of all nuclear installations and/or providing constraints for anti-seismic design and retrofitting of existing structures

  10. Further studies of Fermi-motion effects in lepton scattering from nuclear targets

    International Nuclear Information System (INIS)

    Bodek, A.; Ritchie, J.L.

    1981-01-01

    We have calculated the ratio of deep-inelastic structure functions of nuclear targets to the sum of free-neutron and -proton structure functions. The calculations incorporate structure-function fits which are based on quantum-chromodynamic considerations. This paper is an addendum to an earlier publication in which we calculated the Fermi-motion corrections using other fits to the nucleon structure functions

  11. Skyrme's interaction beyond the mean-field. The DGCM+GOA Hamiltonian of nuclear quadrupole motion

    Energy Technology Data Exchange (ETDEWEB)

    Kluepfel, Peter

    2008-07-29

    This work focuses on the microscopic description of nuclear collective quadrupole motion within the framework of the dynamic Generator-Coordinate-Method(DGCM)+Gaussian-Overlap-Approximation(GOA). Skyrme-type effective interactions are used as the fundamental many-particle interaction. Starting from a rotational invariant, polynomial and topologic consistent formulation of the GCM+GOA Hamiltonian an interpolation scheme for the collective masses and potential is developed. It allows to define the collective Hamiltonian of fully triaxial collective quadrupole dynamics from a purely axial symmetric configuration space. The substantial gain in performance allows the self-consistent evaluation of the dynamic quadrupole mass within the ATDHF-cranking model. This work presents the first large-scale analysis of quadrupole correlation energies and lowlying collective states within the DGCM+GOA model. Different Skyrme- and pairing interactions are compared from old standards up to more recent parameterizations. After checking the validity of several approximations to the DGCM+GOA model - both on the mean-field and the collective level - we proceed with a detailed investigation of correlation effects along the chains of semi-magic isotopes and isotones. This finally allows to define a set of observables which are hardly affected by collective correlations. Those observables were used for a refit of a Skyrme-type effective interaction which is expected to cure most of the problems of the recent parameterizations. Preparing further work, estimates for the correlated ground state energy are proposed which can be evaluated directly from the mean-field model. (orig.)

  12. Perspectives in the theory of nuclear collective motion

    International Nuclear Information System (INIS)

    Klein, A.

    1980-01-01

    This report discusses three different subjects. The first is the development of a generalized version of the VMI (variable moment of inertia) model that ties it to the original form of the IBM (interacting boson model) and provides a possibility of fitting vibrational spectra with generalized vibrational formulas. The second is a suggestion for fitting band crossing calculations of the phenomenological type more completely than has hitherto been done into the framework of the VMI method. The third, which is the most important and far reaching, is the description f a complete mathematical method for the microscopic derivation of the IBM from a conventional shell-model Hamiltonian. In addition to elements already foreseen by previous authors, there is proposed a solution for the most important problem outstanding, not only within the framework of the IBM, but also in all previous work on boson expansion. This is the problem of actually selecting, in a general fashion, the most collective excitations. A criterion is introduced that the subspace constructed from these excitations should possess an average energy that is lower than the rest of the shell model space; the actual implementation of this criterion is explained. 8 tables, 62 references

  13. Sum rule approach to nuclear vibrations

    International Nuclear Information System (INIS)

    Suzuki, T.

    1983-01-01

    Velocity field of various collective states is explored by using sum rules for the nuclear current. It is shown that an irrotational and incompressible flow model is applicable to giant resonance states. Structure of the hydrodynamical states is discussed according to Tomonaga's microscopic theory for collective motions. (author)

  14. Adiabatic time-dependent Hartree-Fock theory of collective motion in finite systems

    International Nuclear Information System (INIS)

    Baranger, M.; Veneroni, M.

    1978-01-01

    We show how to derive the parameters of a phenomenological collective model from a microscopic theory. The microscopic theory is Hartree-Fock, and we start from the time-dependent Hartree-Fock equation. To this we add the adiabatic approximation, which results in a collective kinetic energy quadratic in the velocities, with coefficients depending on the coordinates, as in the phenomenological models. The crucial step is the decomposition of the single-particle density matrix p in the form exp(i/sub chi/) rho/sub omicron/exp(-i/sub chi/), where rho/sub omicron/ represents a time-even Slater determinant and plays the role of coordinate. Then chi plays the role of momentum, and the adiabatic assumption is that chi is small. The energy is expanded in powers of chi, the zeroth-order being the collective potential energy. The analogy with classical mechanics is stressed and studied. The same adiabatic equations of motion are derived in three different ways (directly, from the Lagrangian, from the Hamiltonian), thus proving the consistency of the theory. The dynamical equation is not necessary for writing the energy or for the subsequent quantization which leads to a Schroedinger equation, but it must be used to check the validity of various approximation schemes, particularly to reduce the problem to a few degrees of freedom. The role of the adiabatic hypothesis, its definition, and range of validity, are analyzed in great detail. It assumes slow motion, but not small amplitude, and is therefore suitable for large-amplitude collective motion. The RPA is obtained as the limiting case where the amplitude is also small. The translational mass is correctly given, and the moment of inertia under rotation is that of Thouless and Valatin. For a quadrupole two-body force, the Baranger-Kumar formalism is recovered. The self-consistency brings additional terms to the Inglis cranking formula. Comparison is also made with generator coordinate methods

  15. Nuclear power and the public: an update of collected survey research on nuclear power

    International Nuclear Information System (INIS)

    Rankin, W.L.; Melber, B.D.; Overcast, T.D.; Nealey, S.M.

    1981-12-01

    The purpose of this research was to collect, analyze, and summarize all of the nuclear power-related surveys conducted in the United States through June 1981, that we could obtain. The surveys collected were national, statewide, and areawide in scope. Slightly over 100 surveys were collected for an earlier, similar effort carried out in 1977. About 130 new surveys were added to the earlier survey data. Thus, about 230 surveys were screened for inclusion in this report. Because of space limitations, national surveys were used most frequently in this report, followed distantly by state surveys. In drawing our conclusions about public beliefs and attitudes toward nuclear power, we placed most of our confidence in survey questions that were used by national polling firms at several points in time. A summary of the research findings is presented, beginning with general attitudes toward nuclear power, followed by a summary of beliefs and attitudes about nuclear power issues, and ended by a summary of beliefs and attitudes regarding more general energy issues

  16. Nuclear power and the public: an update of collected survey research on nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Rankin, W.L.; Melber, B.D.; Overcast, T.D.; Nealey, S.M.

    1981-12-01

    The purpose of this research was to collect, analyze, and summarize all of the nuclear power-related surveys conducted in the United States through June 1981, that we could obtain. The surveys collected were national, statewide, and areawide in scope. Slightly over 100 surveys were collected for an earlier, similar effort carried out in 1977. About 130 new surveys were added to the earlier survey data. Thus, about 230 surveys were screened for inclusion in this report. Because of space limitations, national surveys were used most frequently in this report, followed distantly by state surveys. In drawing our conclusions about public beliefs and attitudes toward nuclear power, we placed most of our confidence in survey questions that were used by national polling firms at several points in time. A summary of the research findings is presented, beginning with general attitudes toward nuclear power, followed by a summary of beliefs and attitudes about nuclear power issues, and ended by a summary of beliefs and attitudes regarding more general energy issues.

  17. Stability evaluation of ground considering dynamic vertical ground motion. Pt. 3. Effect of dynamic vertical motions on sliding safety factor of foundation ground and surrounding slope in nuclear power plant

    International Nuclear Information System (INIS)

    Ishikawa, Hiroyuki; Sato, Hiroaki; Kawai, Tadashi; Kanatani, Mamoru

    2003-01-01

    In this report, time differences of the peak accelerations between horizontal and vertical motions were investigated based on the earthquake records on the rock sites and analytical studies were carried out in order to investigate the effect of them to the fluctuations of the minimum sliding safety factors of the foundation ground and surrounding slope of nuclear power plants. Summaries of this report were as follows; (1) Maximum time difference of the peak accelerations between horizontal and vertical motions on the rock sites was approximately 10 seconds in the earthquakes within the epicenter distance of 100 km. (2) Analytical studies that employed the equivalent linear analysis with horizontal and vertical input motions were carried out against the representative models and ground properties of the foundation grounds and surrounding slopes in nuclear power plants. The combinations of the horizontal and vertical motions were determined from the above-mentioned investigation results based on the actual earthquake records. It was revealed that the fluctuations of the minimum sliding safety factors were not seriously affected by the time difference of the peak accelerations between horizontal and vertical motions. (author)

  18. Beyond RPA in nuclear rotation and wobbling motion at high spin

    International Nuclear Information System (INIS)

    Kaneko, Kazunari

    1991-01-01

    A quantum mechanical method of the nuclear rotation and the wobbling motion at high spin beyond the small-oscillation approximation is represented within the framework of time-dependent mean-field theory with some constraints. The constraints which determine the choice of the rotating reference frame are considered in the spin-orientation frame and the principal-axis frame. The quantization under such constraints is performed by making use of the Dirac bracket. Then the commutation relations of the angular momentum are derived. (orig.)

  19. Collectivity and chaoticity in nuclear dynamics

    International Nuclear Information System (INIS)

    Zelevinsky, V.G.

    1992-01-01

    Collective and chaotic features of nuclear dynamics are discussed using simple criteria of complexity of wave functions and their coherence with respect to specific operators. Various physical phenomena are considered in this connection: - coherent interaction of collective modes; - fragmentation and spreading widths; - mixing of compound states and dynamical enhancement; - mean field as a smooth component of complicated dynamics; - coupling through continuum and collectivization of widths; - structure of giant resonances; - statistical properties of unstable states as generalization of canonical random matrix ensembles. (orig.)

  20. Physics of microswimmers—single particle motion and collective behavior: a review

    International Nuclear Information System (INIS)

    Elgeti, J; Winkler, R G; Gompper, G

    2015-01-01

    Locomotion and transport of microorganisms in fluids is an essential aspect of life. Search for food, orientation toward light, spreading of off-spring, and the formation of colonies are only possible due to locomotion. Swimming at the microscale occurs at low Reynolds numbers, where fluid friction and viscosity dominates over inertia. Here, evolution achieved propulsion mechanisms, which overcome and even exploit drag. Prominent propulsion mechanisms are rotating helical flagella, exploited by many bacteria, and snake-like or whip-like motion of eukaryotic flagella, utilized by sperm and algae. For artificial microswimmers, alternative concepts to convert chemical energy or heat into directed motion can be employed, which are potentially more efficient. The dynamics of microswimmers comprises many facets, which are all required to achieve locomotion. In this article, we review the physics of locomotion of biological and synthetic microswimmers, and the collective behavior of their assemblies. Starting from individual microswimmers, we describe the various propulsion mechanism of biological and synthetic systems and address the hydrodynamic aspects of swimming. This comprises synchronization and the concerted beating of flagella and cilia. In addition, the swimming behavior next to surfaces is examined. Finally, collective and cooperate phenomena of various types of isotropic and anisotropic swimmers with and without hydrodynamic interactions are discussed. (report on progress)

  1. Interaction and collective effects in classical-equations-of-motion calculations

    International Nuclear Information System (INIS)

    Bodmer, A.R.

    1981-01-01

    We discuss results obtained with the classical-equations-of-motion (CEOM) approach, with particular reference to interaction (potential energy) and collective effects in central collisions of equal mass nuclei. The essence of the CEOM approach is the classical calculation of all A = A/sub P/ + A/sub T/ trajectories using a 2-body potential V between all pairs of nucleons; V = V/sub short/ + V/sub long/ has a short range repulsion and a longer range attractive tail. In contrast to hydrodynamics, the CEOM approach is microscopic and includes transparency and nonequilibrium effects

  2. Exotic nuclear structures and decays: new nuclear collective phenomena

    International Nuclear Information System (INIS)

    Hamilton, J.H.

    1986-01-01

    Studies of the properties of exotic nuclei have revealed a surprising richness and diversity in their shapes, structures, and decay modes far exceeding our understandings and expectations of even a decay ago. From studies of far-off-stability exotic nuclei have come evidence for the coexistence of different nuclear shapes in the same nucleus, new regions of unusually large deformation, new ground-state phase transitions from one shape to another, new magic numbers but now for deformed shapes, and for the importance of reinforcing shell gaps. New exotic decay modes include a wide variety of beta delayed particle emission and heavy cluster emissions such as 14 C and 24 Ne. The new deformed magic numbers of 38 and 60 seen far off stability clearly support that there are likely other ''magic'' numbers for protons and neutrons which give stability to different deformed shapes. Perhaps these other new magic shell gap numbers at large deformation could influence the sticking of two very heavy nuclei in collisions such as U on Cm. Finally, another area which could have a bearing on the formation, motions, and structures of giant nuclear systems involves the recent observation of very energetic, light particle (proton, alpha) emission with up to 50% and more of the total incoming energy in a collision, for example in 300 MeV 32 S on Ta. 43 refs., 11 figs., 2 tabs

  3. Simultaneous computation of intrabunch and interbunch collective beam motions in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Skripka, Galina, E-mail: galina.skripka@maxlab.lu.se [MAX IV Laboratory, Lund University, SE-22100 Lund (Sweden); Nagaoka, Ryutaro, E-mail: ryutaro.nagaoka@synchrotron-soleil.fr [Synchrotron SOLEIL, Saint Aubin, 91192 Gif-sur-Yvette (France); Klein, Marit; Cullinan, Francis [Synchrotron SOLEIL, Saint Aubin, 91192 Gif-sur-Yvette (France); Tavares, Pedro F. [MAX IV Laboratory, Lund University, SE-22100 Lund (Sweden)

    2016-01-11

    We present the multibunch tracking code mbtrack developed to simulate, in 6-dimensional phase space, single- and multibunch collective instabilities driven by short- and long-range wakefields in storage rings. Multiple bunches, each composed of a large number of macroparticles, are tracked, allowing simulation of both intra- and interbunch motions. Besides analytical impedance models, the code allows employment of numerical wake potentials computed with electromagnetic (EM) field solvers. The corresponding impedances are fitted to a number of known analytical functions and the coefficients obtained in the fit are used as an input to the code. mbtrack performs a dynamic treatment of long-range resistive-wall and harmonic cavity fields, which are likely to be the two major factors impacting multibunch collective motions in many present and future ring-based light sources. Furthermore, it is capable of simulating beam-ion interactions as well as transverse bunch-by-bunch feedback. We describe the physical effects considered in the code and their implementation, which makes use of parallel processing to significantly shorten the computation time. mbtrack is benchmarked against other codes and applied to the MAX IV 3 GeV ring as an example, where the importance of the interplay of various physical effects as well as coupling among different degrees of freedom is demonstrated. - Highlights: • A new 6D multibunch multiparticle tracking code is developed. • The code employs numerical impedance computed for realistic vacuum components. • Effects of passive harmonic cavity and resistive wall are treated. • A method to model interplay between intra- and interbunch motions is developed.

  4. Collective phenomena in relativistic heavy-ion collisions

    Science.gov (United States)

    Wang, Shan

    1998-12-01

    Collective motion in the final state of relativistic nucleus-nucleus collisions, produced by the release of compressional energy built-up during the stage of maximum density, is widely accepted as a good observable to test models and a useful tool to probe the nuclear equation of state. This dissertation presents an experimental study of nuclear collisions at the Bevalac accelerator at Lawrence Berkeley National Laboratory, with special emphasis on collective phenomena. The main detector used is a time projection chamber with more than two million pixels. Using high statistics measurements of all charged final- state fragments in Au + Au reactions at 0.25, 0.4, 0.6, 0.8, 1.0, and 1.15A GeV, we present a new method to unify the description of light fragment spectra and the three main categories of collective motion: sideward flow, squeeze-out, and transverse expansion. In this alternative representation, the speed of collective expansion is shown to be slowest in the plane of the reaction, and is modulated sinusoidally according to fragment azimuth relative to this plane. This simple yet complete characterization of squeeze-out leads to its interpretation as an in-plane retardation of collective expansion. We test momentum space power law behavior by studying the momentum-space densities of fragments up to 4He. We conclude that the simple momentum-space power law consistently describes light participant fragment production at p⊥/A/ge0.2 GeV/c over a remarkably wide range of transverse momentum, azimuth relative to the reaction plane, rapidity, multiplicity and beam energy in intermediate-energy heavy-ion collisions and in particular, the increase in sideward flow with fragment mass is well described by a momentum- space power law under these conditions. This behavior is consistent with composite fragment formation through a statistical coalescence mechanism in momentum space. Our conclusion supports the use of models without composite formation to interpret flow

  5. Theoretical nuclear physics at Yale University

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    Brief summaries of past and planned activities in the following areas are given: models of nuclear structure; models of hadronic structure; hot nuclei; chaos in nuclei; reactions and structure; dissipation, diffusion, and collective motion; and modeling equilibrium and nonequilibrium systems.

  6. Failure data collection from a Swedish nuclear power plant

    International Nuclear Information System (INIS)

    Andersson, B.; Bhattacharyya, A.; Hilding, S.

    1975-01-01

    The Swedish nuclear utilities have formed a joint working group in the field of reliability data of thermal power plants, nuclear and fossil fuelled. The primary task of the working group is to create a standard procedure of collecting failure data from the Swedish nuclear power plants in operation. The failure data will be stored in a joint data bank. A first test collection of such data has been implemented on Oskarshamn I, and the experience with this work is discussed in this report. Reliability analysis of an engineering system is based on the availability of pertinent information on the system components. Right from the beginning within the Swedish nuclear industry the consensus has been that such data can be suitably obtained by monitoring the operating power stations. This has led to a co-operative arrangement between the vendor, ASEA-ATOM and a utility, Oskarshamnsverkets Kraftgrupp AB (OKG) to utilize information from component malfunctions in the reliability analysis. The utility prepares component failure reports which are sent to the vendor for further treatment. Experience gathered to date indicates that this arrangement is effective although many persons are involved in this process of information transmittal. The present set-up is flexible enough to accommodate necessary changes in view of problems which arise now and then in monitoring a complex system like a nuclear power station. This report briefly describes the structure of the failure data collection system. The way in which the raw data collection is done in the station by the owner and the subsequent data processing by the vendor is discussed. A brief status report of the information collected since 1971 is given. It can be concluded that valuable reliability data can be obtained by monitoring component failure reports from an operating power plant. Two requirements are, however, that all the parties involved in the arrangement follow given instructions carefully and that the assumed

  7. Nuclear data collection on virtual instrument

    International Nuclear Information System (INIS)

    Yang Qiang; Lai Wanchang; Hua Yongtai

    2007-01-01

    This paper introduced a kind of nuclear data collection system using a technique of mixed programming. The system uses parallel port to transport data, MATLAB signal processing software is used for data analysis. It has significantly reduced the difficult of spectral analysis software by using the technique. It has realized signal acquisition in real time and data analysis. (authors)

  8. Critical insights into nuclear collectivity from complementary nuclear spectroscopic methods

    Science.gov (United States)

    Garrett, P. E.; Wood, J. L.; Yates, S. W.

    2018-06-01

    Low-energy collectivity of nuclei has been, and is being, characterized in a critical manner using data from a variety of spectroscopic methods, including Coulomb excitation, β decay, inelastic scattering of charged and uncharged particles, transfer reactions, etc. In addition to level energies and spins, transition multipolarities and intensities, lifetimes, and nuclear moments are available. The totality of information from these probes must be considered in achieving an accurate vision of the excitations in nuclei and determining the applicability of nuclear models. From these data, major changes in our view of low-energy collectivity in nuclei have emerged; most notable is the demise of the long-held view of low-energy quadrupole collectivity near closed shells as due to vibrations about a spherical equilibrium shape. In this contribution, we focus on the basic predictions of the spherical harmonic vibrator limit of the Bohr Hamiltonian. Properties such as B(E2) values, quadrupole moments, E0 strengths, etc are outlined. Using the predicted properties as a guide, evidence is cited for and against the existence of vibrational states, and especially multi-phonon states, in nuclei that are, or historically were considered to be, spherical or have a nearly spherical shape in their ground state. It is found that very few of the nuclei that were identified in the last major survey seeking nearly spherical harmonic vibrators satisfy the more stringent guidelines presented herein. Details of these fundamental shifts in our view of low-energy collectivity in nuclei are presented.

  9. Measurement and evaluation of high-rise building response to ground motion generated by underground nuclear explosions

    International Nuclear Information System (INIS)

    Honda, K.K.

    1976-01-01

    As part of the structural response research program being conducted for ERDA, the response behavior of high-rise buildings in Las Vegas, Nevada, due to ground motion caused by underground nuclear explosions (UNEs) at the Nevada Test Site (NTS) has been measured for the past 12 years. Results obtained include variation in dynamic response properties as a function of amplitude of motion, influence of nonstructural partitions in the building response, and comparison of calculated and measured response. These data for three reinforced concrete high-rise buildings, all designed as moment-resisting space frames are presented

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-28

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

  11. What should be learned from the 2011 off the Pacific coast of Tohoku Earthquake to formulate the standard seismic motion of a nuclear power plant

    International Nuclear Information System (INIS)

    Nozu, Atsushi

    2017-01-01

    Although inter plate earthquake is also taken into account in the formulation of standard seismic motion of a nuclear power plant, the lessons of the 2011 off the Pacific coast of Tohoku Earthquake are not fully utilized in the evaluation of the strong motion record. This paper discussed the following three points. (1) During the 2011 off the Pacific coast of Tohoku Earthquake, sharp pulses generated from a narrow area (SPGA: strong motion pulse generation area) on the fault plane determined the maximum amplitude of the earthquake ground motion at the nuclear power plant. (2) In order to accurately calculate this pulse, the current SMGA model is insufficient. (3) The seismic motion evaluated on the assumption that the SPGA is close to a nuclear power plant can exceed the assumption made by power companies. From the studies so far, it is clear that the current SMGA model cannot accurately calculate pulse waves with a time width of 1 to 2 seconds that is technically important, and its causes are clear. For this reason, the SMGA model is not suitable as a seismic source model for establishing the standard seismic motion of a nuclear power plant. It is necessary to have a model that can reproduce the earthquake ground motion due to the 2011 off the Pacific coast of Tohoku Earthquake, in an accuracy of SPGA model or higher. Pulse waves with a time width of 1 to 2 seconds that simultaneously bring about large accelerations and speeds are likely accompany plasticization and cause major damage. (A.O.)

  12. A study on generation of simulated earthquake ground motion for seismic design of nuclear power plant

    International Nuclear Information System (INIS)

    Ichiki, Tadaharu; Matsumoto, Takuji; Kitada, Yoshio; Osaki, Yorihiko; Kanda, Jun; Masao, Toru.

    1985-01-01

    The aseismatic design of nuclear power generation facilities carried out in Japan at present must conform to the ''Guideline for aseismatic design examination regarding power reactor facilities'' decided by the Atomic Energy Commission in 1978. In this guideline, the earthquake motion used for the analysis of dynamic earthquake response is to be given in the form of the magnitude determined on the basis of the investigation of historical earthquakes and active faults around construction sites and the response spectra corresponding to the distance from epicenters. Accordingly when the analysis of dynamic earthquake response is actually carried out, the simulated earthquake motion made in conformity with these set up response spectra is used as the input earthquake motion for the design. For the purpose of establishing the techniques making simulated earthquake motion which is more appropriate and rational from engineering viewpoint, the research was carried out, and the results are summarized in this paper. The techniques for making simulated earthquake motion, the response of buildings and the response spectra of floors are described. (Kako, I.)

  13. Order, chaos and nuclear dynamics: An introduction

    International Nuclear Information System (INIS)

    Swiatecki, W.J.

    1990-08-01

    This is an introductory lecture illustrating by simple examples the anticipated effect on collective nuclear dynamics of a transition from order to chaos in the motions of nucleons inside an idealized nucleus. The destruction of order is paralleled by a transition from a rubber-like to a honey-like behaviour of the independent-particle nuclear model. 10 refs., 6 figs

  14. Collective doses from airborne discharges by the UK nuclear industry

    International Nuclear Information System (INIS)

    Kelly, G.N.

    1981-01-01

    Small quantities of radionuclides are discharged in airborne effluents during the normal operation of nuclear installations. The dispersion of these nuclides in the atmosphere and their subsequent transfer through various sectors of the environment leads to the irradiation of the population. The collective dose to the UK population from airborne discharges in one particular year, 1978, from UK nuclear installations is estimated. The discharges in that year are typical of those in the recent past. Consideration is given to the contribution made by each type of establishment (eg, nuclear power stations, reprocessing plants) and the nuclides which contribute significantly to the collective dose are identified. The distributions of the collective dose in time and among individuals in the exposed population are important features in determining the significance attached to it and both aspects are discussed. The collective dose can be used as a measure of the health detriment associated with the discharge practices considered and is one of several quantities to be taken into account in assessing them. The collective doses from airborne discharges are finally contrasted with those from other sources of exposure of the population. (author)

  15. Collective coordinate models of domain wall motion in perpendicularly magnetized systems under the spin hall effect and longitudinal fields

    Energy Technology Data Exchange (ETDEWEB)

    Nasseri, S. Ali, E-mail: ali.nasseri@isi.it [ISI Foundation - Via Alassio 11/c –10126 Torino (Italy); Politecnico di Torino - Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Moretti, Simone; Martinez, Eduardo [University of Salamanca - Cardenal Plá y Deniel, 22, 37008 Salamanca (Spain); Serpico, Claudio [ISI Foundation - Via Alassio 11/c –10126 Torino (Italy); University of Naples Federico II - Via Claudio 21, 80125 Napoli (Italy); Durin, Gianfranco [ISI Foundation - Via Alassio 11/c –10126 Torino (Italy); Istituto Nazionale di Ricerca Metrologica (INRIM) - Strada delle Cacce 91, 10135 Torino (Italy)

    2017-03-15

    Recent studies on heterostructures of ultrathin ferromagnets sandwiched between a heavy metal layer and an oxide have highlighted the importance of spin-orbit coupling (SOC) and broken inversion symmetry in domain wall (DW) motion. Specifically, chiral DWs are stabilized in these systems due to the Dzyaloshinskii-Moriya interaction (DMI). SOC can also lead to enhanced current induced DW motion, with the Spin Hall effect (SHE) suggested as the dominant mechanism for this observation. The efficiency of SHE driven DW motion depends on the internal magnetic structure of the DW, which could be controlled using externally applied longitudinal in-plane fields. In this work, micromagnetic simulations and collective coordinate models are used to study current-driven DW motion under longitudinal in-plane fields in perpendicularly magnetized samples with strong DMI. Several extended collective coordinate models are developed to reproduce the micromagnetic results. While these extended models show improvements over traditional models of this kind, there are still discrepancies between them and micromagnetic simulations which require further work. - Highlights: • Moving DWs in PMA material maintain their structure under longitudinal in-plane fields. • As a result of longitudinal fields, magnetization in the domains becomes canted. • A critical longitudinal field was identified and correlated with the DMI strength. • A canted collective coordinate model was developed for DW motion under in-plane fields.

  16. Breaking of separability condition for dynamical collective subspace; Onset of quantum chaos in large-amplitude collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Fumihiko [Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study; Yamamoto, Yoshifumi; Marumori, Toshio; Iida, Shinji; Tsukuma, Hidehiko

    1989-11-01

    It is the purpose of the present paper to study 'global structure' of the state space of an N-body interacting fermion system, which exhibits regular, transient and stochastic phases depending on strength of the interaction. An optimum representation called a dynamical representation plays an essential role in this investigation. The concept of the dynamical representation has been introduced in the quantum theory of dynamical subspace in our previous paper, in order to determine self-consistently an optimum collective subspace as well as an optimum collective Hamiltonian. In the theory, furthermore, dynamical conditions called separability and stability conditions have been provided in order to identify the optimum collective subspace as an approximate invariant subspace of the Hamiltonian. Physical meaning of these conditions are clarified from a viewpoint to relate breaking of them with bifurcation of the collectivity and an onset of quantum chaos from the regular collective motion, by illustrating the general idea with numerical results obtained for a simple soluble model. It turns out that the onset of the stochastic phase is associated with dissolution of the quantum numbers to specify the collective subspace and this dissolution is induced by the breaking of the separability condition in the dynamical representation. (author).

  17. Visualization of the collective vortex-like motions in liquid argon and water: Molecular dynamics simulation

    Science.gov (United States)

    Anikeenko, A. V.; Malenkov, G. G.; Naberukhin, Yu. I.

    2018-03-01

    We propose a new measure of collectivity of molecular motion in the liquid: the average vector of displacement of the particles, ⟨ΔR⟩, which initially have been localized within a sphere of radius Rsph and then have executed the diffusive motion during a time interval Δt. The more correlated the motion of the particles is, the longer will be the vector ⟨ΔR⟩. We visualize the picture of collective motions in molecular dynamics (MD) models of liquids by constructing the ⟨ΔR⟩ vectors and pinning them to the sites of the uniform grid which divides each of the edges of the model box into equal parts. MD models of liquid argon and water have been studied by this method. Qualitatively, the patterns of ⟨ΔR⟩ vectors are similar for these two liquids but differ in minor details. The most important result of our research is the revealing of the aggregates of ⟨ΔR⟩ vectors which have the form of extended flows which sometimes look like the parts of vortices. These vortex-like clusters of ⟨ΔR⟩ vectors have the mesoscopic size (of the order of 10 nm) and persist for tens of picoseconds. Dependence of the ⟨ΔR⟩ vector field on parameters Rsph, Δt, and on the model size has been investigated. This field in the models of liquids differs essentially from that in a random-walk model.

  18. The adiabatic versus the diabatic approximation in the decoupling of electron and nuclear motion

    International Nuclear Information System (INIS)

    Every, A.G.

    1975-01-01

    There are two limiting approximations that are used as starting points for the analysis of a system of interacting electrons and nuclei. The more widely used is the adiabatic approximation in which one assumes that the electrons adjust adiabatically to the instantaneous configuration of the nuclei. This yields an effective internuclear potential. In treating the nuclear motion, this potential can legitimately be expanded to fourth order in nuclear displacements from equilibrium. The difficulties of extending this expansion further are discussed. In situations where two adiabatic potentials approach each other the so-called diabatic approximation has to be used. A novel application to non-radioactive processes in solids is discussed. (author)

  19. Microscopic calculations of nuclear matter collective flow in Nb(400 MeV/N) + Nb

    International Nuclear Information System (INIS)

    Hoffer, J.B.; Kruse, H.; Molitoris, J.J.; Stoecker, H.

    1984-01-01

    The recent experimental observation of sidewards peaks in the emission pattern of fragments emitted in collisions of heavy nuclear systems has stimulated a dispute among theorists about how to interpret these data. It has been shown that the observations are in agreement with the results of macroscopic nuclear fluid dynamical calculations, but several microscopic calculations done to simulate the sidewards emission (via the intranuclear cascade (INC) approach) failed - the angular distributions obtained where always forward peaked. A many body equations of motion (EOM) approach to study heavy ion collision has been developed. The approach is analogous to the early work of Bodmer et al., and Wilets et al. Hamilton's equations of motion are solved for an ensemble of nucleons with simultaneous mutual two-body interactions between all particles. The model predicts the sidewards emission peaks for the Nb + Nb reaction

  20. Application of the adiabatic self-consistent collective coordinate method to a solvable model of prolate-oblate shape coexistence

    International Nuclear Information System (INIS)

    Kobayasi, Masato; Matsuyanagi, Kenichi; Nakatsukasa, Takashi; Matsuo, Masayuki

    2003-01-01

    The adiabatic self-consistent collective coordinate method is applied to an exactly solvable multi-O(4) model that is designed to describe nuclear shape coexistence phenomena. The collective mass and dynamics of large amplitude collective motion in this model system are analyzed, and it is shown that the method yields a faithful description of tunneling motion through a barrier between the prolate and oblate local minima in the collective potential. The emergence of the doublet pattern is clearly described. (author)

  1. Thirteen international workshop on nuclear theory. Abstracts

    International Nuclear Information System (INIS)

    1994-01-01

    This brochure contains the abstracts of reports delivered by 40 participants at the 13. International Workshop on Nuclear Theory organized by the Nuclear Theory Group in the Institute for Nuclear research and Nuclear Energy of the Bulgarian academy of Sciences. The main topics treated in the lectures were nucleon correlation effects in nuclei, collective nuclear motions, Wigner quantum systems, pre-equilibrium neutron and photon emission from nuclei, particle-nuclei collision processes at high energies, few-body states, optical potential for neutron-nucleus scattering, relativistic generator coordinate calculations and variational nuclear structure calculations. All reports are included in INIS separately

  2. Estimated collective effective dose to the population from nuclear medicine examinations in Slovenia

    International Nuclear Information System (INIS)

    Skrk, Damijan; Zontar, Dejan

    2013-01-01

    A national survey of patient exposure from nuclear medicine diagnostic procedures was performed by Slovenian Radiation Protection Administration in order to estimate their contribution to the collective effective dose to the population of Slovenia. A set of 36 examinations with the highest contributions to the collective effective dose was identified. Data about frequencies and average administered activities of radioisotopes used for those examinations were collected from all nuclear medicine departments in Slovenia. A collective effective dose to the population and an effective dose per capita were estimated from the collected data using dose conversion factors. The total collective effective dose to the population from nuclear medicine diagnostic procedures in 2011 was estimated to 102 manSv, giving an effective dose per capita of 0.05 mSv. The comparison of results of this study with studies performed in other countries indicates that the nuclear medicine providers in Slovenia are well aware of the importance of patient protection measures and of optimisation of procedures

  3. Competition between collective and single particle excitations in nuclear structure description

    International Nuclear Information System (INIS)

    Petrovici, A.N.

    1983-01-01

    The microscopic description of the quadrupole collective dynamics in even krypton isotopes is presented. A microscopic calculation of Bohr's collective Hamiltonian is used to describe the collective motion in 76 Kr. A single-particle basis calculated in a deformed Woods-Saxon potential leads to the potential energy surface obtained by the Strutinsky renormalization procedure, and to the inertial functions determined in the cranking model approximation. The collective Schroedinger equation is solved numerically to analyse the low-energy, even parity states in 76 Kr. A good agreement between experiment and theory is obtained without specifically adjusting any parameter in the model for this nucleus. Some results regarding statical and dynamical characteristics of sup(74,78,80)Kr isotopes are also presented. The asymmetric rotor model with admixture of two quasiparticles is used to describe the sup(66,68,70)Ge and the sup(64,66)Zn isotopes. The interplay of collective and single particle motions is further investigated by magnetic moment measurements using the method of integral angular correlations perturbed by recoil into gas. The results involve g-factor measurements for 166 Ho, 68 Ge, 64 Zn, 66 Zn and 68 Ga nuclei. Finally, a discussion of further possible improvements and more general developments of the problems under investigation is given. (author)

  4. Fuel-motion diagnostics and cineradiography

    International Nuclear Information System (INIS)

    DeVolpi, A.

    1982-09-01

    Nuclear and non-nuclear applications of cineradiography are reviewed, with emphasis on diagnostic instrumentation for in-pile transient-reactor safety testing of nuclear fuel motion. The primary instrument for this purpose has been the fast-neutron hodoscope, which has achieved quantitative monitoring of time, location, mass, and velocity of fuel movement under the difficult conditions associated with transient-reactor experiments. Alternative diagnostic devices that have been developed have not matched the capabilities of the hodoscope. Other applications for the fuel-motion diagnostic apparatus are also evolving, including time-integrated radiography and direct time- and space-resolved fuel-pin power monitoring. Although only two reactors are now actively equipped with high-resolution fuel-motion diagnostic systems, studies and tests have been carried out in and for many other reactors

  5. Collective motion of active Brownian particles with polar alignment.

    Science.gov (United States)

    Martín-Gómez, Aitor; Levis, Demian; Díaz-Guilera, Albert; Pagonabarraga, Ignacio

    2018-04-04

    We present a comprehensive computational study of the collective behavior emerging from the competition between self-propulsion, excluded volume interactions and velocity-alignment in a two-dimensional model of active particles. We consider an extension of the active brownian particles model where the self-propulsion direction of the particles aligns with the one of their neighbors. We analyze the onset of collective motion (flocking) in a low-density regime (10% surface area) and show that it is mainly controlled by the strength of velocity-alignment interactions: the competition between self-propulsion and crowding effects plays a minor role in the emergence of flocking. However, above the flocking threshold, the system presents a richer pattern formation scenario than analogous models without alignment interactions (active brownian particles) or excluded volume effects (Vicsek-like models). Depending on the parameter regime, the structure of the system is characterized by either a broad distribution of finite-sized polar clusters or the presence of an amorphous, highly fluctuating, large-scale traveling structure which can take a lane-like or band-like form (and usually a hybrid structure which is halfway in between both). We establish a phase diagram that summarizes collective behavior of polar active brownian particles and propose a generic mechanism to describe the complexity of the large-scale structures observed in systems of repulsive self-propelled particles.

  6. Derivation of the Boltzmann Equation for Financial Brownian Motion: Direct Observation of the Collective Motion of High-Frequency Traders

    Science.gov (United States)

    Kanazawa, Kiyoshi; Sueshige, Takumi; Takayasu, Hideki; Takayasu, Misako

    2018-03-01

    A microscopic model is established for financial Brownian motion from the direct observation of the dynamics of high-frequency traders (HFTs) in a foreign exchange market. Furthermore, a theoretical framework parallel to molecular kinetic theory is developed for the systematic description of the financial market from microscopic dynamics of HFTs. We report first on a microscopic empirical law of traders' trend-following behavior by tracking the trajectories of all individuals, which quantifies the collective motion of HFTs but has not been captured in conventional order-book models. We next introduce the corresponding microscopic model of HFTs and present its theoretical solution paralleling molecular kinetic theory: Boltzmann-like and Langevin-like equations are derived from the microscopic dynamics via the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy. Our model is the first microscopic model that has been directly validated through data analysis of the microscopic dynamics, exhibiting quantitative agreements with mesoscopic and macroscopic empirical results.

  7. Ground motion effects

    Energy Technology Data Exchange (ETDEWEB)

    Blume, J A [John A. Blume and Associates, San Francisco, CA (United States)

    1969-07-01

    Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

  8. Ground motion effects

    International Nuclear Information System (INIS)

    Blume, J.A.

    1969-01-01

    Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

  9. High-spin nuclear spectroscopy

    International Nuclear Information System (INIS)

    Diamond, R.M.

    1986-07-01

    High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given

  10. Calculation of nuclear level density parameters of some light deformed medical radionuclides using collective excitation modes of observed nuclear spectra

    International Nuclear Information System (INIS)

    Okuducu, S.; Sarac, H.; Akti, N. N.; Boeluekdemir, M. H.; Tel, E.

    2010-01-01

    In this study the nuclear energy level density based on nuclear collective excitation mechanism has been identified in terms of the low-lying collective level bands at near the neutron binding energy. Nuclear level density parameters of some light deformed medical radionuclides used widely in medical applications have been calculated by using different collective excitation modes of observed nuclear spectra. The calculated parameters have been used successfully in estimation of the neutron-capture cross section basic data for the production of new medical radionuclides. The investigated radionuclides have been considered in the region of mass number 40< A< 100. The method used in the present work assumes equidistance spacing of the collective coupled state bands of the interest radionuclides. The present calculated results have been compared with the compiled values from the literatures for s-wave neutron resonance data.

  11. Characteristics of near-field earthquake ground motion

    International Nuclear Information System (INIS)

    Kim, H. K.; Choi, I. G.; Jeon, Y. S.; Seo, J. M.

    2002-01-01

    The near-field ground motions exhibit special response characteristics that are different from those of ordinary ground motions in the velocity and displacement response. This study first examines the characteristics of near-field ground motion depending on fault directivity and fault normal and parallel component. And the response spectra of the near field ground motion are statistically processed, and are compared with the Regulatory Guide 1.60 spectrum that is present design spectrum of the nuclear power plant. The response spectrum of the near filed ground motions shows large spectral velocity and displacement in the low frequency range. The spectral accelerations of near field ground motion are greatly amplified in the high frequency range for the rock site motions, and in the low frequency range for the soil site motions. As a result, the near field ground motion effects should be considered in the seismic design and seismic safety evaluation of the nuclear power plant structures and equipment

  12. Nuclear physics mathematical methods

    International Nuclear Information System (INIS)

    Balian, R.; Gervois, A.; Giannoni, M.J.; Levesque, D.; Maille, M.

    1984-01-01

    The nuclear physics mathematical methods, applied to the collective motion theory, to the reduction of the degrees of freedom and to the order and disorder phenomena; are investigated. In the scope of the study, the following aspects are discussed: the entropy of an ensemble of collective variables; the interpretation of the dissipation, applying the information theory; the chaos and the universality; the Monte-Carlo method applied to the classical statistical mechanics and quantum mechanics; the finite elements method, and the classical ergodicity [fr

  13. Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

    1984-05-01

    This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage.

  14. Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

    International Nuclear Information System (INIS)

    Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

    1984-05-01

    This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage

  15. Collective motion of groups of self-propelled particles following interacting leaders

    Science.gov (United States)

    Ferdinandy, B.; Ozogány, K.; Vicsek, T.

    2017-08-01

    In order to keep their cohesiveness during locomotion gregarious animals must make collective decisions. Many species boast complex societies with multiple levels of communities. A common case is when two dominant levels exist, one corresponding to leaders and the other consisting of followers. In this paper we study the collective motion of such two-level assemblies of self-propelled particles. We present a model adapted from one originally proposed to describe the movement of cells resulting in a smoothly varying coherent motion. We shall use the terminology corresponding to large groups of some mammals where leaders and followers form a group called a harem. We study the emergence (self-organization) of sub-groups within a herd during locomotion by computer simulations. The resulting processes are compared with our prior observations of a Przewalski horse herd (Hortobágy, Hungary) which we use as results from a published case study. We find that the model reproduces key features of a herd composed of harems moving on open ground, including fights for followers between leaders and bachelor groups (group of leaders without followers). One of our findings, however, does not agree with the observations. While in our model the emerging group size distribution is normal, the group size distribution of the observed herd based on historical data have been found to follow lognormal distribution. We argue that this indicates that the formation (and the size) of the harems must involve a more complex social topology than simple spatial-distance based interactions.

  16. Collective excitation spectra of transitional even nuclei

    International Nuclear Information System (INIS)

    Quentin, P.; Paris-11 Univ., 91 - Orsay; Deloncle, I.; Libert, J.; Sauvage, J.

    1990-01-01

    This talk is dealing with the nuclear low energy collective motion as described in the context of microscopic versions of the Bohr Hamiltonian. Two different ways of building microscopically Bohr collective Hamiltonians will be sketched; one within the framework of the Generator Coordinate Method, the other using the Adiabatic Time-Dependent Hartree-Fock-Boholyubov approximation. A sample of recent results will be presented which pertains to the description of transitional even nuclei and to the newly revisited phenomenon of superdeformation at low spin

  17. Physicochemical characteristics of uranium microparticles collected at nuclear fuel cycle plants

    International Nuclear Information System (INIS)

    Kaurov, G.; Stebelkov, V.; Kolesnikov, O.; Frolov, D.

    2001-01-01

    Any industrial process is accompanied by appearance of some quantity of microparticles of processed matter in the environment in immediate proximity to the manufacturing object. These particles can be transferred in atmosphere and can be collected at some distances from the plant. The determination of characteristics of industrial dust microparticles at nuclear fuel cycle plants (form, size, structure of surface, elemental composition, isotopic composition, presence of fission products, presence of activation products) in conjunction with the ability to connect these characteristics with certain nuclear manufacturing processes can become the main technical method of detecting of undeclared nuclear activity. Systematization of the experimental data on morphology, elemental and isotopic composition of uranium microparticles, collected at nuclear fuel cycle plants, is given. The purpose of this work is to establish the relationship between morphological characteristics of uranium dust microparticles and types of nuclear manufacture and to define the reference attributes of the most informative microparticles

  18. Measurements and simulation of controlled beamfront motion in the Laser Controlled Collective Accelerator

    International Nuclear Information System (INIS)

    Yao, R.L.; Destler, W.W.; Striffler, C.D.; Rodgers, J.; Scgalov, Z.

    1989-01-01

    In the Laser Controlled Collective Accelerator, an intense electron beam is injected at a current above the vacuum space charge limit into an initially evacuated drift tube. A plasma channel, produced by time-sequenced, multiple laser beam ionization of a solid target on the drift tube wall, provides the necessary neutralization to allow for effective beam propagation. By controlling the rate of production of the plasma channel as a function of time down the drift tube, control of the electron beamfront can be achieved. Recent experimental measurements of controlled beamfront motion in this configuration are presented, along with results of ion acceleration experiments conducted using two different accelerating gradients. These results are compared with numerical simulations of the system in which both controlled beamfront motion and ion acceleration is observed consistent with both design expectations and experimental results. 5 refs., 6 figs

  19. Tracking of the nuclear wavepacket motion in cyanine photoisomerization by ultrafast pump-dump-probe spectroscopy.

    Science.gov (United States)

    Wei, Zhengrong; Nakamura, Takumi; Takeuchi, Satoshi; Tahara, Tahei

    2011-06-01

    Understanding ultrafast reactions, which proceed on a time scale of nuclear motions, requires a quantitative characterization of the structural dynamics. To track such structural changes with time, we studied a nuclear wavepacket motion in photoisomerization of a prototype cyanine dye, 1,1'-diethyl-4,4'-cyanine, by ultrafast pump-dump-probe measurements in solution. The temporal evolution of wavepacket motion was examined by monitoring the efficiency of stimulated emission dumping, which was obtained from the recovery of a ground-state bleaching signal. The dump efficiency versus pump-dump delay exhibited a finite rise time, and it became longer (97 fs → 330 fs → 390 fs) as the dump pulse was tuned to longer wavelengths (690 nm → 950 nm → 1200 nm). This result demonstrates a continuous migration of the leading edge of the wavepacket on the excited-state potential from the Franck-Condon region toward the potential minimum. A slowly decaying feature of the dump efficiency indicated a considerable broadening of the wavepacket over a wide range of the potential, which results in the spread of a population distribution on the flat S(1) potential energy surface. The rapid migration as well as broadening of the wavepacket manifests a continuous nature of the structural dynamics and provides an intuitive visualization of this ultrafast reaction. We also discussed experimental strategies to evaluate reliable dump efficiencies separately from other ultrafast processes and showed a high capability and possibility of the pump-dump-probe method for spectroscopic investigation of unexplored potential regions such as conical intersections. © 2011 American Chemical Society

  20. Detection of collective motions in dielectric spectra and the meaning of the generalized Vogel-Fulcher-Tamman equation

    International Nuclear Information System (INIS)

    Nigmatullin, Raoul R.

    2009-01-01

    Based on the reduction property of dielectric spectra associated with the power-law function [∼(jωτ) ±ν ] that appears in the frequency domain, one can develop an effective procedure for detection of different reduced motions (described by the corresponding power-law exponents) in temperature domain. If the power-law exponent ν is related to characteristic relaxation time τ by the relationship ν=ν 0 ln(τ/τ s )/ln(τ/τ 0 ) (here τ s , τ 0 are the characteristic times characterizing a movement over fractal cluster that is defined in Ref. [Ya.E. Ryabov, Yu. Feldman, J. Chem. Phys. 116 (2002) 8610]) and the simple temperature dependence of τ(T)=τ A exp(E/T) obeys the traditional Arrhenius relationship, then one can prove that any extreme point figuring in the complex permittivity ε(jω) spectra (characterized by the values [ω m , y(ω m )]) obeys the generalized Vogel-Fulcher-Tamman (VFT) equation. This important statement confirms the existence of the 'universal' response (UR) (discovered and classified by Jonscher in frequency domain) and opens new possibilities in the detection of the 'hidden' collective motions in temperature region for self-similar (heterogeneous) systems. It gives also the extended interpretation of the VFT equation and allows one to differentiate collective motions passing through an extreme point. This differentiation, in turn, allows one to select the proper fitting function containing one or two (at least) relaxation times for the fitting of the complex permittivity function ε(jω) in the limited frequency domain. This conclusion can allow for the classification of dielectric spectroscopy as the spectroscopy of the reduced (collective) motions, which are described by different power-law exponents on the mesoscale region. The verification of this approach on available DS data (poly(ethylene glycol)-based-single-ion conductors) completely confirms the basic statements of this theory and opens new possibilities in general

  1. Evaluation and summary of seismic response of above ground nuclear power plant piping to strong motion earthquakes

    International Nuclear Information System (INIS)

    Stevenson, J.D.

    1985-01-01

    The purpose of this paper is to summarize the observations and experience which has been developed relative to the seismic behavior of above-ground, building-supported, industrial type piping (similar to piping used in nuclear power plants) in strong motion earthquakes. The paper also contains observations regarding the response of piping in experimental tests which attempted to excite the piping to failure. Appropriate conclusions regarding the behavior of such piping in large earthquakes and recommendations as to future design of such piping to resist earthquake motion damage are presented based on observed behavior in large earthquakes and simulated shake table testing

  2. Nuclear dynamics in phase space

    International Nuclear Information System (INIS)

    Di Toro, M.

    1984-07-01

    We present a unified semiclassical picture of nuclear dynamics, from collective states to heavy ion physics, based on a study of the time evolution of the Wigner distribution function. We discuss in particular the mean field dynamics, in this ''quantal'' phase space, which is ruled by the nuclear Vlasov equation. Simple approximate solutions are worked out for rotational and vibrational collective motions. Giant resonances are shown to be quite well described as scaling modes, which are equivalent to a lowest multipole (up to 1sub(max)=2) distortions of the momentum distribution. Applications are shown to heavy ion physics to study giant resonances on high spin states and dynamical collective effects in subthreshold π-production. Several possible extensions and in particular the inclusion of two-body collision terms are finally discussed

  3. Occupational dose reduction developments and data collected at nuclear power plants

    International Nuclear Information System (INIS)

    Dionne, B.J.; Baum, J.W.

    1984-01-01

    Occupational dose reduction developments and data collected at nuclear power plants have been described. Written descriptions of repetitive high dose jobs, their collective dose equivalent ranges and list of dose reduction techniques will aid in reducing collective dose equivalents from these dose-reduction targets. Knowing which components contribute to high maintenance or repair dose will aid in reducing routine maintenance collective dose equivalents. The radwaste dose reduction improvements will aid in reducing radwaste operations collective dose equivalent and reduce the number of radwaste workers who exceed their administrative dose limits. The identification and rating of managers' and workers' ALARA incentives will provide the basis for recommendations to improve dose reduction incentives. Lastly, the identification and rating of the key components of an ALARA program will aid in the development and coordination of the nuclear station ALARA programs

  4. On the theory of nuclear quadrupole oscillations

    International Nuclear Information System (INIS)

    Abrosimov, V.I.; Strutinskij, V.M.

    1978-01-01

    Presented is a deduction and a convinient writing form of the secular equation for nuclear quadrupole oscillations. The deduction is consistent with usual random phase approximation. It is regarded that the oscillations of the nuclear average potential are adiabatic with respect to formation of the Cooper pairs and the collective motion arises as a result of the coherent distortion of the quasiparticle wave functions. The energy gap changes are also taken into account

  5. Correlation of horizontal and vertical components of strong ground motion for response-history analysis of safety-related nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yin-Nan, E-mail: ynhuang@ntu.edu.tw [Dept. of Civil Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (China); Yen, Wen-Yi, E-mail: b01501059@ntu.edu.tw [Dept. of Civil Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (China); Whittaker, Andrew S., E-mail: awhittak@buffalo.edu [Dept. of Civil, Structural and Environmental Engineering, MCEER, State University of New York at Buffalo, Buffalo, NY 14260 (United States)

    2016-12-15

    Highlights: • The correlation of components of ground motion is studied using 1689 sets of records. • The data support an upper bound of 0.3 on the correlation coefficient. • The data support the related requirement in the upcoming edition of ASCE Standard 4. - Abstract: Design standards for safety-related nuclear facilities such as ASCE Standard 4-98 and ASCE Standard 43-05 require the correlation coefficient for two orthogonal components of ground motions for response-history analysis to be less than 0.3. The technical basis of this requirement was developed by Hadjian three decades ago using 50 pairs of recorded ground motions that were available at that time. In this study, correlation coefficients for (1) two horizontal components, and (2) the vertical component and one horizontal component, of a set of ground motions are computed using records from a ground-motion database compiled recently for large-magnitude shallow crustal earthquakes. The impact of the orientation of the orthogonal horizontal components on the correlation coefficient of ground motions is discussed. The rules in the forthcoming edition of ASCE Standard 4 for the correlation of components in a set of ground motions are shown to be reasonable.

  6. Collective and non-collective structures in nuclei of mass region A ≈ 125

    International Nuclear Information System (INIS)

    Singh, A. K.

    2014-01-01

    Generation of angular momentum in nuclei is a key question in nuclear structure studies. In single particle model, it is due to alignment of spin of individual nucleon available in the valence space, whereas coherent motion of nucleons are assumed in the collective model. The nuclei near the closed shell at Z = 50 with mass number A ≈ 120-125 represent ideal cases to explore the interplay between these competing mechanisms and the transition from non-collective to collective behavior or vice versa. Recent spectroscopic studies of nuclei in this region reveal several non-collective maximally aligned states representing the first kind of excitation mechanism, where 8-12 particles above the 114 Sn align their spins to generate these states. Deformed rotational bands feeding the non-collective states in the spin range I=20-25 and excitation energies around 10 MeV have also been observed. Structure of the collective and non-collective states are discussed in the framework of Cranked-Nilsson-Strutinsky model

  7. The crossover from collective motion to periphery diffusion for two-dimensional adatom-islands on Cu(111)

    International Nuclear Information System (INIS)

    Karim, Altaf; Kara, Abdelkader; Rahman, Talat S; Trushin, Oleg

    2011-01-01

    The diffusion of two-dimensional adatom-islands (up to 100 atoms) on Cu(111) has been studied, using the self-learning kinetic Monte Carlo method (Trushin et al 2005 Phys. Rev. B 72 115401). A variety of multiple- and single-atom processes are revealed in the simulations, and the size dependences of the diffusion coefficients and effective diffusion barriers are calculated for each. From the tabulated frequencies of events found in the simulation, we show a crossover from diffusion due to the collective motion of the island to a regime in which the island diffuses through periphery-dominated mass transport. This crossover occurs for island sizes between 13 and 19 atoms. For islands containing 19-100 atoms the scaling exponent is 1.5, which is in good agreement with previous work. The diffusion of islands containing 2-13 atoms can be explained primarily on the basis of a linear increase of the barrier for the collective motion with the size of the island. (fast track communication)

  8. Collective versus single-particle motion in quantum many-body systems from the perspective of an integrable model

    Energy Technology Data Exchange (ETDEWEB)

    Haemmerling, Jens; Gutkin, Boris; Guhr, Thomas, E-mail: jens.haemmerling@uni-due.d [Universitaet Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg (Germany)

    2010-07-02

    We study the emergence of collective dynamics in the integrable Hamiltonian system of two finite ensembles of coupled harmonic oscillators. After identification of a collective degree of freedom, the Hamiltonian is mapped onto a model of Caldeira-Leggett type, where the collective coordinate is coupled to an internal bath of phonons. In contrast to the usual Caldeira-Leggett model, the bath in the present case is part of the system. We derive an equation of motion for the collective coordinate which takes the form of a damped harmonic oscillator. We show that the distribution of quantum transition strengths induced by the collective mode is determined by its classical dynamics.

  9. Collective versus single-particle motion in quantum many-body systems from the perspective of an integrable model

    International Nuclear Information System (INIS)

    Haemmerling, Jens; Gutkin, Boris; Guhr, Thomas

    2010-01-01

    We study the emergence of collective dynamics in the integrable Hamiltonian system of two finite ensembles of coupled harmonic oscillators. After identification of a collective degree of freedom, the Hamiltonian is mapped onto a model of Caldeira-Leggett type, where the collective coordinate is coupled to an internal bath of phonons. In contrast to the usual Caldeira-Leggett model, the bath in the present case is part of the system. We derive an equation of motion for the collective coordinate which takes the form of a damped harmonic oscillator. We show that the distribution of quantum transition strengths induced by the collective mode is determined by its classical dynamics.

  10. The second RPA description for the decay of the one-phonon nuclear collective states at finite temperature

    International Nuclear Information System (INIS)

    Yannouleas, C.; Jang, S.

    1986-01-01

    The zero-temperature second RPA is generalized to finite temperatures through the use of the method of linearization of the equations of motion. After elimination of the quadruples, for low enough temperatures and within the subspace spanned by the doubles, a proper symmetrization yields an eigenvalue equation which exhibits formal properties like the simple RPA. From this second RPA eigenvalue equation, a closed formula for the spreading width of an isolated collective state is extracted. The second RPA can be recast in the form of a generalized collision term and be compared with the method of the Bethe-Salpeter equation for the two-body Green function. However, the second RPA method (and results) contrasts with the approach (and corresponding results) of the Boltzmann collision term, which is usually viewed as the appropriate agent for nuclear dissipation. (orig.)

  11. Dynamical calculations of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1984-01-01

    With the goal of determining the magnitude and mechanism of nuclear dissipation from comparisons of predictions with experimental data, we describe recent calculations in a unified macroscopic-microscopic approach to large-amplitude collective nuclear motion such as occurs in fission and heavy-ion reactions. We describe the time dependence of the distribution function in phase space of collective coordinates and momenta by a generalized Fokker-Planck equation. The nuclear potential energy of deformation is calculated as the sum of repulsive Coulomb and centrifugal energies and an attractive Yukawa-plus-exponential potential, the inertia tensor is calculated for a superposition of rigid-body rotation and incompressible, nearly irrotational flow by use of the Werner-Wheeler method, and the dissipation ensor that describes the conversion of collective energy into single-particle excitation energy is calculated for two prototype mechanisms that represent opposite extremes of large and small dissipation. We solve the generalized Hamilton equations of motion for the first moments of the distribution function to obtain the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as dynamical thresholds, capture cross sections, and ternary events in heavy-ion reactions. 33 references

  12. Pairing and seniority in an equations-of-motion approach to nuclear structure theory

    International Nuclear Information System (INIS)

    Covello, A.; Andreozzi, F.; Gargano, A.; Porrino, A.

    1990-01-01

    In this paper, some achievements of an equations-of-motion approach to nuclear structure theory are discussed. As an introduction to the main subject, a brief survey of some early work is given. We then describe a formalism for treating the pairing-force problem and show, by numerical appllications, that at the lowest order of approximation it provides an advantageous alternative to the BCS method. Finally, we discuss how to treat a general shell-model Hamiltonian within the framework of the seniority scheme. This makes it possible to further reduce seniority-truncated shell-model spaces, as is illustrated by examples. (orig.)

  13. Linearised collective Schroedinger equation for nuclear quadrupole surface vibrations

    International Nuclear Information System (INIS)

    Greiner, M.; Heumann, D.; Scheid, W.

    1990-11-01

    The linearisation of the Schroedinger equation for nuclear quadrupole surface vibrations yields a new spin degree of freedom, which is called collective spin and has a value of 3/2. With the introduction of collective spin dependent potentials, this linearised Schroedinger equation is then used for the description of low energy spectra and electromagnetic transition probabilities of some even-odd Xe, Ir and Au nuclei which have a spin 3/2 in their groundstate. (orig.)

  14. History of ground motion programs at the Nevada Test Site

    International Nuclear Information System (INIS)

    Banister, J.R.

    1984-01-01

    Some measurements were made in the atmospheric testing era, but the study of ground motion from nuclear tests became of wider interest after the instigation of underground testing. The ground motion generated by underground nuclear test has been investigated for a number of reasons including understanding basic phenomena, operational and safety concerns, yield determination, stimulation of earthquake concerns, and developing methods to aid in treaty verifications. This history of ground motion programs will include discussing early studies, high yield programs, Peaceful Nuclear Explosions tests, and some more recent developments. 6 references, 10 figures

  15. Third international radioecological conference. The fate of spent nuclear fuel: problems and reality. Abstracts collection

    International Nuclear Information System (INIS)

    1996-01-01

    In the book there are abstracts collection of the third International radioecological conference 'The fate of spent nuclear fuel: problems and reality' (June, 22-27, 1996, Krasnoyarsk, Russia) and International workshop meeting 'Defence nuclear waste disposal in Russia'. In the collection there are materials concerning the problems of technology, economics, ecology and safety of two types of nuclear cycle as well as the problems of health of population living near nuclear ojects and on contaminated territories

  16. Sound-like collective mode excitation with pion absorption in nuclear matter

    International Nuclear Information System (INIS)

    Qiu Xijiun; Shen Jianguo; Huang Lingfang

    1985-01-01

    The relativistic mean field theory consistent with bulk properties of nuclear matter is extended to study the excitations of the sound-like collective modes in nuclear matter. Corresponding relativistic mean field equations are solved numerically and self-consistently. The effective mass of nucleon, the speed of the sound and the amplitude of the sound-like solution are calculated. When the nuclear density is near or greater than the saturation density, the sound-like non-trivial solution could be found

  17. MotionExplorer: exploratory search in human motion capture data based on hierarchical aggregation.

    Science.gov (United States)

    Bernard, Jürgen; Wilhelm, Nils; Krüger, Björn; May, Thorsten; Schreck, Tobias; Kohlhammer, Jörn

    2013-12-01

    We present MotionExplorer, an exploratory search and analysis system for sequences of human motion in large motion capture data collections. This special type of multivariate time series data is relevant in many research fields including medicine, sports and animation. Key tasks in working with motion data include analysis of motion states and transitions, and synthesis of motion vectors by interpolation and combination. In the practice of research and application of human motion data, challenges exist in providing visual summaries and drill-down functionality for handling large motion data collections. We find that this domain can benefit from appropriate visual retrieval and analysis support to handle these tasks in presence of large motion data. To address this need, we developed MotionExplorer together with domain experts as an exploratory search system based on interactive aggregation and visualization of motion states as a basis for data navigation, exploration, and search. Based on an overview-first type visualization, users are able to search for interesting sub-sequences of motion based on a query-by-example metaphor, and explore search results by details on demand. We developed MotionExplorer in close collaboration with the targeted users who are researchers working on human motion synthesis and analysis, including a summative field study. Additionally, we conducted a laboratory design study to substantially improve MotionExplorer towards an intuitive, usable and robust design. MotionExplorer enables the search in human motion capture data with only a few mouse clicks. The researchers unanimously confirm that the system can efficiently support their work.

  18. Ground Motion Prediction Trends For Eastern North America Based on the Next Generation Attenuation East Ground Motion Database

    Science.gov (United States)

    Cramer, C. H.; Kutliroff, J.; Dangkua, D.

    2010-12-01

    A five-year Next Generation Attenuation (NGA) East project to develop new ground motion prediction equations for stable continental regions (SCRs), including eastern North America (ENA), has begun at the Pacific Earthquake Engineering Research (PEER) Center funded by the Nuclear Regulatory Commission (NRC), the U.S. Geological Survey (USGS), the Electric Power Research Institute (EPRI), and the Department of Energy (DOE). The initial effort focused on database design and collection of appropriate M>4 ENA broadband and accelerograph records to populate the database. Ongoing work has focused on adding records from smaller ENA earthquakes and from other SCRs such as Europe, Australia, and India. Currently, over 6500 horizontal and vertical component records from 60 ENA earthquakes have been collected and prepared (instrument response removed, filtering to acceptable-signal band, determining peak and spectral parameter values, quality assurance, etc.) for the database. Geologic Survey of Canada (GSC) strong motion recordings, previously not available, have also been added to the NGA East database. The additional earthquakes increase the number of ground motion recordings in the 10 - 100 km range, particularly from the 2008 M5.2 Mt. Carmel, IL event, and the 2005 M4.7 Riviere du Loup and 2010 M5.0 Val des Bois earthquakes in Quebec, Canada. The goal is to complete the ENA database and make it available in 2011 followed by a SCR database in 2012. Comparisons of ground motion observations from four recent M5 ENA earthquakes with current ENA ground motion prediction equations (GMPEs) suggest that current GMPEs, as a group, reasonably agree with M5 observations at short periods, particularly at distances less than 200 km. However, at one second, current GMPEs over predict M5 ground motion observations. The 2001 M7.6 Bhuj, India, earthquake provides some constraint at large magnitudes, as geology and regional attenuation is analogous to ENA. Cramer and Kumar, 2003, have

  19. Theoretical research in nuclear structure and nuclear collective motion. Final report, March 1, 1986 - February 28, 1997

    International Nuclear Information System (INIS)

    1997-01-01

    Since what follows is the final report that the author will ever submit to DOE, it seems appropriate to him that it should be a long-term review, since he has received support from DOE and its predecessor agencies since 1957. The report also contains some material from the earliest years of his career. The next three sections contain an account of what the author thinks he has accomplished in the areas of quantum electrodynamics, nuclear forces, meson pair theory, low energy theory, lie algebra, many body theory, and many more physics topic. There follows a bibliography, consistently referred to in the previous sections and a Curriculum vitae for completeness

  20. Yukawa Tomonaga and nuclear physics

    International Nuclear Information System (INIS)

    Udagawa, Takeshi

    2006-01-01

    Yukawa and Tomonaga made epoch-making contributions to the development of elementary particle physics; Yukawa proposed the meson theory of the nuclear force and Tomonaga developed renormalization theory in QED. The nuclear force is, of course, the basis of all nuclear physics. In this sense, Yukawa's work set the foundations for nuclear physics. Tomonaga worked in his late years on problems of collective motion appearing in many many-particle-systems, nuclear systems being one of the examples. Yukawa and Tomonaga were also deeply involved in founding the Institute of Fundamental Physics and Institute for Nuclear Study, through which they made invaluable contributions to the development of the field of nuclear physics. It is almost impossible to report in this short article on all of what they have achieved and thus I would like to discuss here their contributions to nuclear physics only in a limited scope, based on my personal reminiscence of them. (author)

  1. Review of the nuclear reactor thermal hydraulic research in ocean motions

    Energy Technology Data Exchange (ETDEWEB)

    Yan, B.H., E-mail: yanbh3@mail.sysu.edu.cn

    2017-03-15

    The research and development of small modular reactor in floating platform has been strongly supported by Chinese government and enterprises. Due to the effect of ocean waves, the thermal hydraulic behavior and safety characteristics of floating reactor are different from that of land-based reactor. Many scholars including the author have published their research and results in open literatures. Much of these literatures are valuable but there are also some contradictory conclusions. In this wok, the nuclear reactor thermal hydraulic research in ocean motions was systematically summarized. Valuable results and experimental data were analyzed and classified. Inherent mechanism for controversial issues in different experiments was explained. Necessary work needed in the future was suggested. Through this work, we attempt to find as many valuable results as possible for the designing and subsequent research.

  2. Review of the nuclear reactor thermal hydraulic research in ocean motions

    International Nuclear Information System (INIS)

    Yan, B.H.

    2017-01-01

    The research and development of small modular reactor in floating platform has been strongly supported by Chinese government and enterprises. Due to the effect of ocean waves, the thermal hydraulic behavior and safety characteristics of floating reactor are different from that of land-based reactor. Many scholars including the author have published their research and results in open literatures. Much of these literatures are valuable but there are also some contradictory conclusions. In this wok, the nuclear reactor thermal hydraulic research in ocean motions was systematically summarized. Valuable results and experimental data were analyzed and classified. Inherent mechanism for controversial issues in different experiments was explained. Necessary work needed in the future was suggested. Through this work, we attempt to find as many valuable results as possible for the designing and subsequent research.

  3. A study of collective coordinates and dynamical groups in nuclear theory

    International Nuclear Information System (INIS)

    Papadopolos, Z.

    1983-01-01

    Lie-algebraic techniques for the group action on manifolds given as a direct product of coset spaces and group manifolds are developed. The microscopic realisation of the Mass Quadrupole Collective Model (MQC) in the S0(3)xSO(n) and GLsub(+)(3, R)xSO(n) schemes is studied. The problem of the separation of the kinetic energy and the velocity field into a collective and an intrinsic part is analyzed. Different coordinate schemes in phase space for the U(n)-invariant collective motion and the U(3) dynamical group are introduced. In the GL(3,C)xU(n) scheme, the invariant volume element in the new coordinates and a completely orthonormal basis is constructed. (orig.) [de

  4. Collective effective dose in Europe from x-ray and nuclear medicine procedures

    International Nuclear Information System (INIS)

    Bly, R.; Jaervinen, H.; Jahnen, A.; Olerud, H.; Vassileva, J.; Vogiatzi, S.

    2015-01-01

    Population doses from radiodiagnostic (X-ray and nuclear medicine) procedures in Europe were estimated based on data collected from 36 European countries. For X-ray procedures in EU and EFTA countries (except Liechtenstein) the collective effective dose is 547 500 man Sv, resulting in a mean effective dose of 1.06 mSv per caput. For all European countries included in the survey the collective effective dose is 605 000 man Sv, resulting in a mean effective dose of 1.05 mSv per caput. For nuclear medicine procedures in EU countries and EFTA (except Liechtenstein) countries the collective effective dose is 30 700 man Sv, resulting in a mean effective dose of 0.06 mSv per caput. For all European countries included in the survey the collective effective dose is 31 100 man Sv, resulting in a mean effective dose of 0.05 mSv per caput. (authors)

  5. Simulated earthquake ground motions

    International Nuclear Information System (INIS)

    Vanmarcke, E.H.; Gasparini, D.A.

    1977-01-01

    The paper reviews current methods for generating synthetic earthquake ground motions. Emphasis is on the special requirements demanded of procedures to generate motions for use in nuclear power plant seismic response analysis. Specifically, very close agreement is usually sought between the response spectra of the simulated motions and prescribed, smooth design response spectra. The features and capabilities of the computer program SIMQKE, which has been widely used in power plant seismic work are described. Problems and pitfalls associated with the use of synthetic ground motions in seismic safety assessment are also pointed out. The limitations and paucity of recorded accelerograms together with the widespread use of time-history dynamic analysis for obtaining structural and secondary systems' response have motivated the development of earthquake simulation capabilities. A common model for synthesizing earthquakes is that of superposing sinusoidal components with random phase angles. The input parameters for such a model are, then, the amplitudes and phase angles of the contributing sinusoids as well as the characteristics of the variation of motion intensity with time, especially the duration of the motion. The amplitudes are determined from estimates of the Fourier spectrum or the spectral density function of the ground motion. These amplitudes may be assumed to be varying in time or constant for the duration of the earthquake. In the nuclear industry, the common procedure is to specify a set of smooth response spectra for use in aseismic design. This development and the need for time histories have generated much practical interest in synthesizing earthquakes whose response spectra 'match', or are compatible with a set of specified smooth response spectra

  6. Collective control of a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rognin, L

    1995-06-01

    Nowadays, mainly related to the increasing complexity of working environments, working activities become more and collective. The present research on the paradoxical nature of working teams, considered from a reliability point of view. This document is composed of four Sections. The first Section introduces the context of the research, its objectives and the underlying assumptions. In the second Section, we describe a working situation, which is the control of a nuclear reactor. Relations between cooperative work and reliability are discussed in the third Section. Finally, in the fourth Section, a synthesis of the research and some perspectives are proposed. (authors). 7 refs.

  7. Collective control of a nuclear reactor

    International Nuclear Information System (INIS)

    Rognin, L.

    1995-06-01

    Nowadays, mainly related to the increasing complexity of working environments, working activities become more and collective. The present research on the paradoxical nature of working teams, considered from a reliability point of view. This document is composed of four Sections. The first Section introduces the context of the research, its objectives and the underlying assumptions. In the second Section, we describe a working situation, which is the control of a nuclear reactor. Relations between cooperative work and reliability are discussed in the third Section. Finally, in the fourth Section, a synthesis of the research and some perspectives are proposed. (authors). 7 refs

  8. Nuclear collective states at finite temperature

    International Nuclear Information System (INIS)

    Milian, A.; Barranco, M.; Mas, D.; Lombard, R.J.

    1987-04-01

    The Energy Density Method (EDM) has been used to study low-lying nuclear collective states as well as isoscalar giant resonances at finite temperature (T). Giant states have been studied by computing the corresponding strength function moments (sum rules) in the Random-Phase Approximation (RPA). For the description of the low lying states we have resorted to a variety of models from the rather sophisticated RPA method to liquid drop and schematic models. It has been found that low lying states are most affected by thermal effects, giant resonances being little affected in the range of temperatures here studied

  9. Application of a self-consistent theory of large amplitude collective motion to the generalized Meshkov-Glick-Lipkin model

    International Nuclear Information System (INIS)

    Umar, A.S.; Klein, A.

    1986-01-01

    A recent formulation of the theory of large amplitude collective motion in the adiabatic limit is applied to a generalized monopole shell model. Numerical calculations are carried out for the three-level model, approximately equivalent to a classical system with two degrees of freedom. Our results go somewhat beyond previous treatments of this system and provide substantiation for the validity of the method, in suitable parameter ranges, as a way of recognizing and decoupling the collective and the non-collective degrees of freedom. (orig.)

  10. Current status of ground motions evaluation in seismic design guide for nuclear power facilities. Investigation on IAEA and US.NRC

    International Nuclear Information System (INIS)

    Nakajima, Masato; Ito, Hiroshi; Hirata, Kazuta

    2009-01-01

    Recently, IAEA (International Atomic Energy Agency) and US.NRC (US. Nuclear Regulatory Commission) published several standards and technical reports on seismic design and safety evaluation for nuclear power facilities. This report summarizes the current status of the international guidelines on seismic design and safety evaluation for nuclear power facilities in order to explore the future research topics. The main results obtained are as follows: 1 IAEA: (1) In the safety standard series, two levels are defined as seismic design levels, and design earthquake ground motion is determined corresponding to each seismic design level. (2) A new framework on seismic design which consists of conventional deterministic method and risk-based method is discussed in the technical report although the framework is not adopted in the safety guidelines. 2 USA: (1) US.NRC discusses a performance-based seismic design framework which has been originally developed by the private organization (American Society of Civil Engineers). (2) Design earthquakes and earthquake ground motion are mainly evaluated and determined based on probabilistic seismic hazard evaluations. 3 Future works: It should be emphasized that IAEA and US.NRC have investigated the implementation of risk-based concept into seismic design. The implementation of risk-based concept into regulation and seismic design makes it possible to consider various uncertainties and to improve accountability. Therefore, we need to develop the methods for evaluating seismic risk of structures, and to correlate seismic margin and seismic risk quantitatively. Moreover, the probabilistic method of earthquake ground motions, that is required in the risk-based design, should be applied to sites in Japan. (author)

  11. Nuclear Collective Hamiltonian and Deformations; Yadernyj kollektivnyj gamil'tonian i deformatsii

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Krishna [Niels Bohr Institute, University of Copenhagen, Copenhagen (Denmark)

    1968-12-15

    The scope and limitations of a recently developed treatment of collective quadrupole motion of even-even nuclei are reviewed. This method is based on Bohr's collective Hamiltonian and the pairing-plus-quadrupole model. With an exact, numerical treatment of the couplings between the five components of quadrupole motion, the theory is able to explain and predict many trends in the low-lying levels and electromagnetic moments of nuclei in the W-Os-Pt region. The zero-point quantal motion plays an important role in spreading the nuclear wave-function in the {beta}-{gamma} plane so that the nucleus is affected essentially by the behaviour of the collective Hamiltonian away from the equilibrium shape. The {gamma} -dependence of the Hamiltonian, especially the prolate-oblate difference term of the potential function, plays a crucial role in the splitting of the 2'{sup +} and 4{sup +} states and the non-zero quadrupole moments of I {ne} 0 states, which can occur even if the equilibrium shape is spherical or completely asymmetric with {gamma} = 30 Degree-Sign . The anharmonicities of the six inertial functions of Bohr's Hamiltonian cause {beta}-{gamma} band-mixing in the W isotopes, reduce the ground-{beta}-{gamma} band-mixing in the Os isotopes, and counteract the prolate-oblate difference term so that the spectrum of the calculated {sup 196}Pt appears to be vibrational. The calculation for {sup 196}Pt gives a large, oblate quadrupole moment of the first 2{sup +} state as well as a small cross-over transition from the ground state to the second 2{sup +} state. However, the calculated 2+ states of {sup 192-196}Pt are too high by 0.1-0.2 MeV, and the calculated B(E2; 2{yields}2') values for the region are too large by about a factor of two. Some possible ways of improvement are indicated. (author) [Russian] Rassmatrivajutsja vozmozhnosti i ogranichenija nedavno razvitoj traktovki kollektivnogo kvadrupol'nogo dvizhenija v chetno-chetnyh jadrah. Jetot metod osnovan na

  12. The eyes, ears and collective voice for nuclear transport

    International Nuclear Information System (INIS)

    Green, L.

    2000-01-01

    Transport is a vital part of the nuclear industry and the safety record of radioactive materials transport across the world is excellent. This record is due primarily to well-founded regulations developed by such intergovernmental organisations as the International Atomic Energy Agency and the International Maritime Organisation. It is due, also, to the professionalism of those in the industry. Attitudes to nuclear transport are important. They have the potential, if not heeded, and not responded to sensitively and convincingly to make life very much more difficult for those committed to the safe, reliable and efficient transport of nuclear materials. What is required is a balanced situation, which takes account both of the public's attitudes and industry's need for an efficient operation. The voices of the nuclear transport industry and those who value the industry need to be heard. The World Nuclear Transport Institute was established to provide the nuclear transport industry with the collective eyes, ears and voice in the key intergovernmental organisations which are so important to it. The nuclear transport industry has a safety record which could be regarded as a model for the transport of dangerous goods of all kinds. The industry is situated within a comprehensive and strict regime of national and international standards and regulations. That is the message to be disseminated, and that is the commitment of the World Nuclear Transport Institute as it works to protect and to promote the safe, efficient and reliable transport of radioactive materials. (author)

  13. Microscopic nuclear-dissipation mechanism as damping of collective motion in the second RPA

    International Nuclear Information System (INIS)

    Yannouleas, C.; Dworzecka, M.; Griffin, J.J.

    1982-01-01

    A microscopic model for the damping of the one-phonon RPA collective state, absolute value c > = Q/sub c/ 0 > /sub S//sub R/, has been previously described. This one-phonon RPA collective state is defined within a restricted subspace, S/sub R/, of the discrete 1p-1h structure. Its damping is described within an extended subspace, S = S/sub R/ + S/sub A/, by the time evolution of a wave packet according to the RPA and the Second RPA approximations of the complete Schroedinger equation when initialized with the one-phonon state. The one-phonon state, however, is unable to describe time-varying oscillations of the mean field. Such oscillations require wave packets formed by linear superposition of the RPA many-phonon eigenstates. Coherent time-varying oscillations of the mean field (multi-phonon initial states) are discussed

  14. Anharmonicity in nuclear wobbling motion

    International Nuclear Information System (INIS)

    Oi, M.

    2007-01-01

    An unexpected strong anharmonicity was observed in the wobbling spectrum in 163 Lu. In an attempt to understand what causes the deviation from the original wobbling model by Bohr and Mottelson, an analysis is presented using several different approaches, such as exact diagonalization, a semiclassical model to deal with anharmonic wobbling motion, and a microscopic method based on the self-consistent cranking calculation

  15. Brief biographical sketches of the research staff of the Nuclear Theory Group

    International Nuclear Information System (INIS)

    1992-01-01

    Brief summaries of past and planned activities in the following areas are given: models of nuclear structure; models of hadronic structure; hot nuclei; chaos in nuclei; reactions and structure; dissipation, diffusion, and collective motion; and modeling equilibrium and nonequilibrium systems

  16. Nuclear physics at Ganil; a compilation january 1983 december 1988

    International Nuclear Information System (INIS)

    1989-01-01

    The results of some of the experiments carried out at GANIL from 1983 to 1988 are summarized. Theoretical and experimental work on the following fields are presented: nuclear structure, reaction mechanisms, hot nuclear matter, production and properties of exotic nuclei, collective motions in nuclei, peripheral collisions, multi-fragment emission, pions and photons and technical developments. A list of the papers from the experiments carried out at GANIL, together with scientific activities are given

  17. Prompt muon-induced fission: A probe for nuclear friction in large-amplitude collective motion

    International Nuclear Information System (INIS)

    Oberacker, V.E.; Umar, A.S.; Wells, J.C.; Strayer, M.R.; Maruhn, J.A.; Reinhard, P.G.

    1998-01-01

    Excited muonic atoms in the actinide region may induce prompt fission by inverse internal conversion, i.e. the excitation energy of the muonic atom is transferred to the nucleus. The authors solve the time dependent Dirac equation for the muonic spinor wave function in the Coulomb field of the fissioning nucleus on a 3-dimensional lattice and demonstrate that the muon attachment probability to the light fission fragment is a measure of the nuclear energy dissipation between the outer fission barrier and the scission point

  18. Nuclear law in motion. Report on the 15th regional meeting of the German section of AIDN/INLA e.V

    International Nuclear Information System (INIS)

    Feldmann, Ulrike

    2017-01-01

    For the 15th time the German National Group of the Association Internationale du Droit Nucleaire/International Nuclear Law Association (AIDN/IN-LA) e.V. organised a regional conference. 90 participants from 15 countries, including representatives of Euratom and OECD/NEA, met in Bonn on 28 and 29 September to exchange views on current issues of nuclear law. The Rhine, which was in sight of the conference centre and connects countries, provided an excellent backdrop not only for the conference that connects nations, but also for the title of the conference ''Atomic Energy Law in Motion'' and for various lectures on nuclear transport.

  19. From Regional Hazard Assessment to Nuclear-Test-Ban Treaty Support - InSAR Ground Motion Services

    Science.gov (United States)

    Lege, T.; Kalia, A.; Gruenberg, I.; Frei, M.

    2016-12-01

    There are numerous scientific applications of InSAR methods in tectonics, earthquake analysis and other geologic and geophysical fields. Ground motion on local and regional scale measured and monitored via the application of the InSAR techniques provide scientists and engineers with plenty of new insights and further understanding of subsurface processes. However, the operational use of InSAR is not yet very widespread. To foster the operational utilization of the Copernicus Sentinel Satellites in the day-to-day business of federal, state and municipal work and planning BGR (Federal Institute for Geosciences and Natural Resources) initiated workshops with potential user groups. Through extensive reconcilement of interests and demands with scientific, technical, economic and governmental stakeholders (e.g. Ministries, Mining Authorities, Geological Surveys, Geodetic Surveys and Environmental Agencies on federal and state level, SMEs, German Aerospace Center) BGR developed the concept of the InSAR based German National Ground Motion Service. One important backbone for the nationwide ground motion service is the so-called Persistent Scatterer Interferometry Wide Area Product (WAP) approach developed with grants of European research funds. The presentation shows the implementation of the ground motion service and examples for product developments for operational supervision of mining, water resources management and spatial planning. Furthermore the contributions of Copernicus Sentinel 1 radar data in the context of CTBT are discussed. The DInSAR processing of Sentinel 1 IW (Interferometric Wide Swath) SAR acquisitions from January 1st and 13th Jan. 2016 allow for the first time a near real time ground motion measurement of the North Korean nuclear test site. The measured ground displacements show a strong spatio-temporal correlation to the calculated epicenter measured by teleseismic stations. We are convinced this way another space technique will soon contribute even

  20. Collection and evalution of abnormal occurrences in German nuclear power plants

    International Nuclear Information System (INIS)

    Hoffmeister

    1976-01-01

    The systematic consideration of operating experiences which must be recorded, collected and evaluated, is important for the realisation of the aim of greater safety in nuclear power stations. Since commissioning of the first nuclear power stations in West Germany all significant events were communicated to the 'Laender' authorities responsible for controlling compliance with the licensing requirements. The evaluation of these events assured that the necessary consequences were carried out to prevent any recurrence. A systematic consideration of the operating experiences, however, was missing; therefore our institute was made responsible by the Federal Ministry of the Interior with the agreement of the 'Laender' authorities to record, collect and evaluate in accordance with reporting criteria and a classification system related to safety relevance. (orig./RW) [de

  1. Seismic Hazards in Site Evaluation for Nuclear Installations. Specific Safety Guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-08-15

    This Safety Guide was prepared under the IAEA programme for safety standards for nuclear installations. It supplements the Safety Requirements publication on Site Evaluation for Nuclear Installations. The present publication provides guidance and recommends procedures for the evaluation of seismic hazards for nuclear power plants and other nuclear installations. It supersedes Evaluation of Seismic Hazards for Nuclear Power Plants, IAEA Safety Standards Series No. NS-G-3.3 (2002). In this publication, the following was taken into account: the need for seismic hazard curves and ground motion spectra for the probabilistic safety assessment of external events for new and existing nuclear installations; feedback of information from IAEA reviews of seismic safety studies for nuclear installations performed over the previous decade; collective knowledge gained from recent significant earthquakes; and new approaches in methods of analysis, particularly in the areas of probabilistic seismic hazard analysis and strong motion simulation. In the evaluation of a site for a nuclear installation, engineering solutions will generally be available to mitigate, by means of certain design features, the potential vibratory effects of earthquakes. However, such solutions cannot always be demonstrated to be adequate for mitigating the effects of phenomena of significant permanent ground displacement such as surface faulting, subsidence, ground collapse or fault creep. The objective of this Safety Guide is to provide recommendations and guidance on evaluating seismic hazards at a nuclear installation site and, in particular, on how to determine: (a) the vibratory ground motion hazards, in order to establish the design basis ground motions and other relevant parameters for both new and existing nuclear installations; and (b) the potential for fault displacement and the rate of fault displacement that could affect the feasibility of the site or the safe operation of the installation at

  2. Modular sludge collection system for a nuclear steam generator

    International Nuclear Information System (INIS)

    Appleman, R.H.; Bein, J.D.; Powasaki, F.S.

    1986-01-01

    A sludge collection system is described for a vertically oriented nuclear steam generator wherein vapors produced in the steam generator pass through means for separating entrained liquid from the vapor prior to the vapor being discharged from the steam generator. The sludge collection system comprises: an upwardly open chamber for collecting the separated liquid and feedwater entering the steam generator; upwardly open sludge collecting containers positioned within the chamber, wherein each of the containers includes a top rim encompassing an opening leading to the interior of each container; generally flat, perforated covers, each of the covers being positioned over one of the openings such that a gap is formed between the cover and the adjacent top rim; sludge agitating means on at least one of the containers; and sludge removal means on at least one of the containers

  3. Consideration on the relation between dynamic seismic motion and static seismic coefficient for the earthquake proof design of slope around nuclear power plant

    International Nuclear Information System (INIS)

    Ito, Hiroshi; Kitahara, Yoshihiro; Hirata, Kazuta

    1986-01-01

    When the large cutting slopes are constructed closed to around nuclear power plants, it is important to evaluate the stability of the slopes during the strong earthquake. In the evaluation, it may be useful to clarify relationship between the static seismic coefficient and dynamic seismic force corresponded to the basic seismic motion which is specified for designing the nuclear power facilities. To investigate this relation some numerical analyses are conducted in this paper. As the results, it is found that dynamic forces considering the amplified responses of the slopes subjected to the basic seismic motion with a peak acceleration of 500 gals at the toe of the slopes, are approximately equal to static seismic force which generates in the slopes when the seismic coefficients of k = 0.3 is applied. (author)

  4. Effective collective dose imparted by a medicine nuclear service to Cordoba and Jaen populations

    International Nuclear Information System (INIS)

    Arias, M.C.; Galvez, M.; Torres, M.

    1997-01-01

    The application of diagnostic techniques in nuclear medicine is ever growing as part of clinical daily routine. Although the diagnostic procedures carry a negligible clinical risk, the introduction of radioactive substances into the patient makes it imperative to determine the effective dose to minimize the stochastic effects to the patient thus establishing the collective dose to the community. The aim of our work is to study the collective effective dose imparted by Nuclear Medicine Service during 1997 to Cordoba and Jaen inhabitants (1 448 988). The nuclear medicine techniques of bone exploration with 11 454 mSv-person (4,6 mSv/exploration) and thyroid scintigraphy with 6181 mSv-person (7,0 mSv /exploration) are the main techniques implicated in the relative contribution to the total annual effective collective dose of 35 901.2 mSv-person

  5. Nuclear matter kinetic coefficients and damping of finite nuclear collective modes

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de.

    1986-06-01

    By carrying the general description of one-body observables beyond the mean-field approximation, those correlation terms responsible for Kinetic phenomena and those involved in the renormalization of the G-matrix mean-field in finite nuclei are identified. A Kinetic equation for the one-body density is obtained. Estimates for transport coefficients and for the damping of zero sound are obtained which point to the inadequacy of hydrodynamical descriptions of collective nuclear modes and indicate that collisional damping in large nuclei may account for one or a few tenths of the observed widths. (S.D.) [pt

  6. Nuclear fission induced by heavy ions

    International Nuclear Information System (INIS)

    Newton, J.O.

    1988-09-01

    Because the accelerators of the 50's and 60's mostly provided beams of light ions, well suited for studying individual quantum states of low angular momentum or reactions involving the transfer of one or two nucleons, the study of fission, being an example of large-scale collective motion, has until recently been outside of the mainstream of nuclear research. This situation has changed in recent years, due to the new generation of accelerators capable of producing beams of heavy ions with energies high enough to overcome the Coulomb barriers of all stable nuclei. These have made possible the study of new examples of large-scale collective motions, involving major rearrangements of nuclear matter, such as deep-inelastic collisions and heavy-ion fusion. Perhaps the most exciting development in the past few years is the discovery that dissipative effects (nuclear viscosity) play an important role in fission induced by heavy ions, contrary to earlier assumptions that the viscosity involved in fission was very weak and played only a minor role. This review will be mainly concerned with developments in heavy-ion induced fission during the last few years and have an emphasis on the very recent results on dissipative effects. Since heavy-ion bombardment usually results in compound systems with high excitation energies and angular momenta, shell effects might be expected to be small, and the subject of low energy fission, where they are important, will not be addressed. 285 refs., 58 figs

  7. Dimensionality reduction of collective motion by principal manifolds

    Science.gov (United States)

    Gajamannage, Kelum; Butail, Sachit; Porfiri, Maurizio; Bollt, Erik M.

    2015-01-01

    While the existence of low-dimensional embedding manifolds has been shown in patterns of collective motion, the current battery of nonlinear dimensionality reduction methods is not amenable to the analysis of such manifolds. This is mainly due to the necessary spectral decomposition step, which limits control over the mapping from the original high-dimensional space to the embedding space. Here, we propose an alternative approach that demands a two-dimensional embedding which topologically summarizes the high-dimensional data. In this sense, our approach is closely related to the construction of one-dimensional principal curves that minimize orthogonal error to data points subject to smoothness constraints. Specifically, we construct a two-dimensional principal manifold directly in the high-dimensional space using cubic smoothing splines, and define the embedding coordinates in terms of geodesic distances. Thus, the mapping from the high-dimensional data to the manifold is defined in terms of local coordinates. Through representative examples, we show that compared to existing nonlinear dimensionality reduction methods, the principal manifold retains the original structure even in noisy and sparse datasets. The principal manifold finding algorithm is applied to configurations obtained from a dynamical system of multiple agents simulating a complex maneuver called predator mobbing, and the resulting two-dimensional embedding is compared with that of a well-established nonlinear dimensionality reduction method.

  8. Vibrational motions in rotating nuclei studied by Coulomb excitations

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R [Kyushu Univ., Fukuoka (Japan). Dept. of Physics

    1998-03-01

    As is well-known Coulomb excitation is an excellent tool to study the nuclear collective motions. Especially the vibrational excitations in rotating nuclei, which are rather difficult to access by usual heavy-ion fusion reactions, can be investigated in detail. Combined with the famous 8{pi}-Spectrometer, which was one of the best {gamma}-ray detector and had discovered some of superdeformed bands, such Coulomb excitation experiments had been carried out at Chalk River laboratory just before it`s shutdown of physics division. In this meeting some of the experimental data are presented and compared with the results of theoretical investigations. (author)

  9. Maintenance planning support method for nuclear power plants based on collective decision making

    International Nuclear Information System (INIS)

    Shimizu, Shunichi; Sakurai, Shoji; Takaoka, Kazushi; Kanemoto, Shigeru; Fukutomi, Shigeki

    1992-01-01

    Inspection and maintenance planning in nuclear power plants is conducted by decision making based on experts' collective consensus. However, since a great deal of time and effort is required to reach a consensus among expert judgments, the establishment of effective decision making methods is necessary. Therefore, the authors developed a method for supporting collective decision making, based on a combination of three types of decision making methods; the Characteristic Diagram method, Interpretative Structural Modeling method, and the Analytic Hierarchy Process method. The proposed method enables us to determine the evaluation criteria systematically for collective decision making, and also allows extracting collective decisions using simplified questionnaires. The proposed method can support reaching a consensus of groups effectively through the evaluation of collective decision structural models and their characteristics. In this paper, the effectiveness of the proposed method was demonstrated through its application to the decision making problem concerning whether or not the improved ultrasonic testing equipment should be adopted at nuclear power plants. (author)

  10. Canonical form of an elastoplastic model of nuclear fusion

    International Nuclear Information System (INIS)

    Mikhajlova, T.I.; Mikhajlov, I.N.; Do Dang, G.

    1997-01-01

    Starting from equations of motion describing the fusion process in symmetrical nuclear systems of low angular momenta we reconstruct the collective Lagrangian and dissipation Rayleigh functions. This opens new perspectives in studying the dynamical effects in the heavy nuclei collisions. In particular, it provides a basis for a quantal description of the fusion process and accompanying its effects

  11. A cooperative NRC/CEA research project on earthquake ground motion on soil sites: overview

    International Nuclear Information System (INIS)

    Murphy, A.J.; Mohammadioun, B.

    1989-10-01

    This paper provides an overview of a multi-phase experiment being conducted jointly by the U.S. Nuclear Regulatory Commission and the French Commissariat a l'Energie Atomique. The objective of the experiment is to collect a comprehensive set of data on the propagation of earthquake ground motions vertically through a shallow soil column (on the order of several tens of meters). The data will be used to validate several of the available engineering computer codes for modeling earthquake ground motion. The data set will also be used to develop an improved understanding of the earthquake source function and the potential for non-linear effects controlling the propagation through the shallow soil column

  12. Proceedings of the 33rd International Workshop on Nuclear Theory (IWNT-33)

    International Nuclear Information System (INIS)

    Georgieva, A. I.; Minkov, N.

    2014-01-01

    The main topics of the 2014 Workshop: nuclear structure and reactions; symmetries and dynamics; collective and intrinsic motions of nuclei; exotic nuclei; few-body and many-fermion systems; nuclear astrophysics and related topics are part of the NTL’s program for basic nuclear physics research. This broad range of subjects gives a space for the participants to cover the most actual points of view relating the theory with experiment, providing interpretation and predictions, bridging interdisciplinary topics related to nuclear structure and reactions. The Workshop was attended by 42 participants from 19 scientific institutions of 11 countries

  13. Surface motion induced by nuclear explosions beneath Pahute Mesa. Part I. Halfbreak, Greeley, Scotch, Boxcar events

    International Nuclear Information System (INIS)

    Perret, W.R.

    1976-10-01

    Results of surface motion studies conducted by Sandia Laboratories during seven underground nuclear explosions detonated beneath Pahute Mesa, Areas 19 and 20 of the Nevada Test Site, between 1966 and 1973 are reported. The report is divided into two parts of which this, Part I, includes (1) descriptions of the Pahute Mesa geological environment and of the purposes and instrumentation used in these programs (Chapter 1), and (2) description of four events, the data derived from each, and analysis of these data. These Part I events are HALFBEAK (Chapter 2), GREELEY (Chapter 3), SCOTCH (Chapter 4), and BOXCAR (Chapter 5) for all of which a nominally radial array of gage stations yielded data as a function of distance primarily, although in a few cases data were derived from stations at widely separated azimuths from the explosion. Results of the analysis indicate that average propagation velocity through the geologic column between the explosions and mesa surface was about 8800 ft/sec and that for horizontal distances greater than shot depth, refraction occurred within rhyolite flows with characteristic velocity of about 12,300 ft/sec. There is evidence which suggests possible deeper refraction at a velocity between 18,000 and 21,000 ft/sec. Only the verticle motion peaks follow a pattern amenable to regression analysis because geometrical effects influence horizontal motion amplitudes differently as horizontal distances increase. Particle velocities vary roughly as the inverse square of slant or radial range with exponent values ranging from -3.9 to -1.3. Displacements follow a similar pattern with exponents ranging from about -6 to -2. Displacement profiles at various times during the motion and displacement hodographs in the vertical-radial plane aid in understanding several local phenomena implied by individual motion records

  14. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  15. Motion as perturbation. II. Development of the method for dosimetric analysis of motion effects with fixed-gantry IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Opp, Daniel; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir, E-mail: vladimir.feygelman@moffitt.org [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2014-06-15

    Purpose: In this work, the feasibility of implementing a motion-perturbation approach to accurately estimate volumetric dose in the presence of organ motion—previously demonstrated for VMAT-–is studied for static gantry IMRT. The method's accuracy is improved for the voxels that have very low planned dose but acquire appreciable dose due to motion. The study describes the modified algorithm and its experimental validation and provides an example of a clinical application. Methods: A contoured region-of-interest is propagated according to the predefined motion kernel throughout time-resolved 4D phantom dose grids. This timed series of 3D dose grids is produced by the measurement-guided dose reconstruction algorithm, based on an irradiation of a staticARCCHECK (AC) helical dosimeter array (Sun Nuclear Corp., Melbourne, FL). Each moving voxel collects dose over the dynamic simulation. The difference in dose-to-moving voxel vs dose-to-static voxel in-phantom forms the basis of a motion perturbation correction that is applied to the corresponding voxel in the patient dataset. A new method to synchronize the accelerator and dosimeter clocks, applicable to fixed-gantry IMRT, was developed. Refinements to the algorithm account for the excursion of low dose voxels into high dose regions, causing appreciable dose increase due to motion (LDVE correction). For experimental validation, four plans using TG-119 structure sets and objectives were produced using segmented IMRT direct machine parameters optimization in Pinnacle treatment planning system (v. 9.6, Philips Radiation Oncology Systems, Fitchburg, WI). All beams were delivered with the gantry angle of 0°. Each beam was delivered three times: (1) to the static AC centered on the room lasers; (2) to a static phantom containing a MAPCHECK2 (MC2) planar diode array dosimeter (Sun Nuclear); and (3) to the moving MC2 phantom. The motion trajectory was an ellipse in the IEC XY plane, with 3 and 1.5 cm axes. The period

  16. Damping in nuclear collective modes in a semiclassical fluid-dynamical approximation

    International Nuclear Information System (INIS)

    Vignolo, C.E.; Hernandez, Susana

    1989-01-01

    A semiclassical fluiddynamical model based on an usual scaling approximation (SCA) was extended to investigate the role of one and two-body dissipation in the widths of nuclear collective modes. The competition between one and two-body viscosity in: i) the collisionless (elastic) limit; ii) the hydrodynamical case and iii) the general viscoelastic regime is examined over the whole range of nuclear collision time scales. Numerical solutions are investigated for the first magnetic 2 - twist mode in 208 Pb. (Author) [es

  17. The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T; Harris, D; Lay, T; Myers, S C; Pasyanos, M E; Richards, P; Rodgers, A J; Walter, W R; Zucca, J J

    2008-02-11

    The last ten years have brought rapid growth in the development and use of three-dimensional (3D) seismic models of earth structure at crustal, regional and global scales. In order to explore the potential for 3D seismic models to contribute to important societal applications, Lawrence Livermore National Laboratory (LLNL) hosted a 'Workshop on Multi-Resolution 3D Earth Models to Predict Key Observables in Seismic Monitoring and Related Fields' on June 6 and 7, 2007 in Berkeley, California. The workshop brought together academic, government and industry leaders in the research programs developing 3D seismic models and methods for the nuclear explosion monitoring and seismic ground motion hazard communities. The workshop was designed to assess the current state of work in 3D seismology and to discuss a path forward for determining if and how 3D earth models and techniques can be used to achieve measurable increases in our capabilities for monitoring underground nuclear explosions and characterizing seismic ground motion hazards. This paper highlights some of the presentations, issues, and discussions at the workshop and proposes a path by which to begin quantifying the potential contribution of progressively refined 3D seismic models in critical applied arenas.

  18. Three lectures on macroscopic aspects of nuclear dynamics

    International Nuclear Information System (INIS)

    Swiatecki, W.J.

    1979-03-01

    These lectures concentrate on macroscopic aspects of nuclear dynamics, those aspects that come into prominence when the number of nucleons, A, is large, A >> 1. An attempt is made to set up a theory of the dynamics of nuclear shape changes, for small (sub-sonic) collective velocities. To set up the equations of motion one needs three forces: conservative, dissipative, and inertial. The first lecture deals with statics, i.e., it discusses methods of treating the Potential Energy Function of nuclear systems. From the Potential Energy the conservative forces that drive the time evolution of a nuclear configuration can be deduced. The division of the underlying potential energy into Local, Proximity, and Global terms is stressed. The second lecture deals with dynamical aspects, especially with the nuclear Dissipation Function, which describes how dissipative frictional forces oppose the conservative driving forces. The underlying physics is the approximate validity of the Independent-Particle model. This, combined with the Randomization Hypothesis, leads to simple formulas that suggest that dissipative forces may often overshadow the inertial forces. The third lecture outlines the kind of dynamics that results from the balance of these forces, and describes a number of applications to nuclear fission and heavy-ion collisions of this New Dynamics. Particularly simple equations of motion are set up, and some of the consequences are explored. 18 references, 31 figures, 3 tables

  19. WIX: statistical nuclear multifragmentation with collective expansion and Coulomb forces

    Science.gov (United States)

    Randrup, J.∅rgen

    1993-10-01

    By suitable augmentation of the event generator FREESCO, a code WIX has been constructed with which it is possible to simulate the statistical multifragmentation of a specified nuclear source, which may be both hollow and deformed, in the presence of a collective expansion and with the interfragment Coulomb forces included.

  20. Wobbling motion in high spin states

    International Nuclear Information System (INIS)

    Onishi, Naoki

    1982-01-01

    By generalizing the cranking model, interwoven motions of collective and non-collective rotation of nuclei are treated as three dimensional non-uniform rotations including precession and wobbling. Classical trajectories are obtained for the + j vector + = 30 h/2π sphere. A method of quantization for wobbling motions is discussed and is applied to estimate excitation energies. (author)

  1. Collective statement on the role of research in a nuclear regulatory context

    International Nuclear Information System (INIS)

    2001-01-01

    In the present context of deregulation and privatisation of the nuclear industry, maintaining an adequate level of nuclear safety research is a primary concern for nuclear regulators, researchers and nuclear power plant licensees, as well as for government officials and the public. While these different stakeholders may have common concerns and interests, there may also be differences. At the international level, it is important to understand that divisions exist both within and among countries, not only in national cultures but also in the way regulators, researchers and licensees view the rote of research. An international gathering under the auspices of the OECD Nuclear Energy Agency (NEA) took place in June 2001, bringing together heads of nuclear regulatory bodies of NEA Member countries, senior regulators, senior executives of research organisations and leaders from the nuclear industry to discuss their perceptions of the rote of research in a nuclear regulatory context. This collective statement represents an international consensus on a rationale for regulatory research for currently operating nuclear reactors and for future reactors, and sets forth specific recommendations to NEA standing technical committees and Member countries. The intended audience is primarily nuclear safety regulators, senior researchers and industry leaders. Government authorities, nuclear power plant operators and the general public may also be interested. (author)

  2. Collective dose to the European Community from nuclear industry effluents discharge in 1978

    CERN Document Server

    Camplin, W C

    1983-01-01

    The results are presented of a study to evaluate the collective dose commitment to the population of the European Community from effluents released by the nuclear industry within the EC in 1978. Airborne and liquid effluent discharge data have been taken from published sources, and computer modelling techniques have been used to predict the transfer of radioactivity through the environment to man. The collective dose commitments due to discharges from each nuclear installation have been evaluated and the comparative significance of individual radionuclides and their pathways to man have been considered. Airborne releases resulted in an estimated collective effective dose equivalent commitment of 95 man Sv, the major part of which is due to carbon-14 from both power stations and reprocessing plants. The collective effective dose equivalent commitment from liquid effluents is estimated to be 408 man Sv, mostly due to caesium-137 and other radionuclides from the Sellafield (formerly Windscale) reprocessing plant...

  3. Theoretical interpretation of the nuclear structure of 88Se within the ACM and the QPM models.

    Science.gov (United States)

    Gratchev, I. N.; Thiamova, G.; Alexa, P.; Simpson, G. S.; Ramdhane, M.

    2018-02-01

    The four-parameter algebraic collective model (ACM) Hamiltonian is used to describe the nuclear structure of 88Se. It is shown that the ACM is capable of providing a reasonable description of the excitation energies and relative positions of the ground-state band and γ band. The most probable interpretation of the nuclear structure of 88Se is that of a transitional nucleus. The Quasiparticle-plus-Phonon Model (QPM) was also applied to describe the nuclear motion in 88Se. Preliminarily calculations show that the collectivity of second excited state {2}2+ is weak and that this state contains a strong two-quasiparticle component.

  4. ELIMINATING CONSERVATISM IN THE PIPING SYSTEM ANALYSIS PROCESS THROUGH APPLICATION OF A SUITE OF LOCALLY APPROPRIATE SEISMIC INPUT MOTIONS

    International Nuclear Information System (INIS)

    Crawford, Anthony L.; Spears, Robert E.; Russell, Mark J.

    2009-01-01

    Seismic analysis is of great importance in the evaluation of nuclear systems due to the heavy influence such loading has on their designs. Current Department of Energy seismic analysis techniques for a nuclear safety-related piping system typically involve application of a single conservative seismic input applied to the entire system (1). A significant portion of this conservatism comes from the need to address the overlapping uncertainties in the seismic input and in the building response that transmits that input motion to the piping system. The approach presented in this paper addresses these two sources of uncertainty through the application of a suite of 32 input motions whose collective performance addresses the total uncertainty while each individual motion represents a single variation of it. It represents an extension of the soil-structure interaction analysis methodology of SEI/ASCE 43-05 (2) from the structure to individual piping components. Because this approach is computationally intensive, automation and other measures have been developed to make such an analysis efficient. These measures are detailed in this paper

  5. Report of the U.S. Nuclear Regulatory Commission Piping Review Committee. Summary and evaluation of historical strong-motion earthquake seismic response and damage to aboveground industrial piping

    International Nuclear Information System (INIS)

    1985-04-01

    The primary purpose of this report is to collect in one reference document the observation and experience that has been developed with regard to the seismic behavior of aboveground, building-supported, industrial-type process piping (similar to piping used in nuclear power plants) in strong-motion earthquakes. The report will also contain observations regarding the response of piping in strong-motion experimental tests and appropriate conclusions regarding the behavior of such piping in large earthquakes. Recommendations are included covering the future design of such piping to resist earthquake motion damage based on observed behavior in large earthquakes and simulated shake table testing. Since available detailed data on the behavior of aboveground (building-supported) piping are quite limited, this report will draw heavily on the observations and experiences of experts in the field. In Section 2 of this report, observed earthquake damage to aboveground piping in a number of large-motion earthquakes is summarized. In Section 3, the available experience from strong-motion testing of piping in experimental facilities is summarized. In Section 4 are presented some observations that attempt to explain the observed response of piping to strong-motion excitation from actual earthquakes and shake table testing. Section 5 contains the conclusions based on this study and recommendations regarding the future seismic design of piping based on the observed strong-motion behavior and material developed for the NPC Piping Review Committee. Finally, in Section 6 the references used in this study are presented. It should be understood that the use of the term piping in this report, in general, is limited to piping supported by building structures. It does not include behavior of piping buried in soil media. It is believed that the seismic behavior of buried piping is governed primarily by the deformation of the surrounding soil media and is not dependent on the inertial response

  6. Nuclear shapes: From the mundane to the exotic

    International Nuclear Information System (INIS)

    Yates, S.W.

    1994-01-01

    The collection of protons and neutrons that forms an atomic nucleus can be characterized as having a shape. Surprisingly, the nuclei of most atoms are not spherical but exhibit shapes that are football-like, pear-like, etc. Following a brief review of the characteristics of these open-quotes mundaneclose quotes nuclear shapes, recent observations of nuclei that are superdeformed or even hyperdeformed are presented. In addition, the evidence for more exotic nuclei that can be described as exhibiting halos, forming a nuclear sausage, or undergoing a scissors-like motion are examined. The discussion concludes with some speculation about additional exotic shapes, such as the nuclear banana. Since nuclear shapes cannot be observed directly, one must rely on knowledge from indirect sources. Some of the details about these sources of information, including excitation spectra and nuclear lifetimes, are presented

  7. Nuclear nonproliferation

    International Nuclear Information System (INIS)

    Neubert, M.

    1992-01-01

    The following motion was put before the United Kingdom House of Commons on 3rd February 1992 and agreed; that this House, recognising the potential dangers of the rapidly changing world order, welcomes the recent proposals for substantial reductions in nuclear weaponry, the growing support for the non-proliferation treaty and progress in the implementation of the United Nations Security Council Resolutions concerning the dismantling of Iraqi nuclear, chemical and biological capabilities; urges the Government to play their full part in helping the relevant authorities in the Commonwealth of Independent States to dismantle their nuclear devices, to safeguard their nuclear components and to discourage the proliferation of nuclear expertise; and believes it is of the first importance that Britain retains an effective and credible minimum nuclear deterrent as security in a world where there remain many sources of instability. The record of arguments for and against the motion in the debate is presented. (author)

  8. A Microscopic Quantal Model for Nuclear Collective Rotation

    International Nuclear Information System (INIS)

    Gulshani, P.

    2007-01-01

    A microscopic, quantal model to describe nuclear collective rotation in two dimensions is derived from the many-nucleon Schrodinger equation. The Schrodinger equation is transformed to a body-fixed frame to decompose the Hamiltonian into a sum of intrinsic and rotational components plus a Coriolis-centrifugal coupling term. This Hamiltonian (H) is expressed in terms of space-fixed-frame particle coordinates and momenta by using commutator of H with a rotation angle. A unified-rotational-model type wavefunction is used to obtain an intrinsic Schrodinger equation in terms of angular momentum quantum number and two-body operators. A Hartree-Fock mean-field representation of this equation is then obtained and, by means of a unitary transformation, is reduced to a form resembling that of the conventional semi-classical cranking model when exchange terms and intrinsic spurious collective excitation are ignored

  9. The residual proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The essential role of the valence, residual p-n interaction in the development of collectivity, though long known in general terms, has recently become increasingly apparent. A brief review of the p-n interaction is given, including some very basic nuclear data that illustrate its effects and the phenomenological N p N n scheme and the P-factor. This is followed by a discussion of recent experimental extractions of p-n matrix elements throughout the periodic table and theoretical efforts to understand them, in terms of both Shell and Nilsson models. 20 refs., 13 figs

  10. Nonlinear seismic behavior of a CANDU containment building subjected to near-field ground motions

    International Nuclear Information System (INIS)

    Choi, In Kil; Ahn, Seong Moon; Choun, Young Sun; Seo, Jeong Moon

    2004-01-01

    The standard response spectrum proposed by US NRC has been used as a design earthquake for the design of Korean nuclear power plant structures. A survey on some of the Quaternary fault segments near Korean nuclear power plants is ongoing. It is likely that these faults will be identified as active ones. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of the nuclear power plants located near the fault. Near-fault ground motions are the ground motions that occur near an earthquake fault. In general, the near-fault ground motion records exhibit a distinctive long period pulse like time history with very high peak velocities. These features are induced by the slip of the earthquake fault. Near-fault ground motions, which have caused much of the damage in recent major earthquakes, can be characterized by a pulse-like motion that exposes the structure to a high input energy at the beginning of the motion. In this study, nonlinear dynamic time-history analyses were performed to investigate the seismic behavior of a CANDU containment structure subjected to various earthquake ground motions including the near-field ground motions

  11. NEA contributions to the worldwide collection, compilation and dissemination of nuclear reaction data

    International Nuclear Information System (INIS)

    Dupont, E.

    2012-01-01

    The NEA Data Bank is an international centre of reference for basic nuclear tools used in the analysis and prediction of phenomena in different nuclear applications. The Data Bank collects and compiles computer codes and scientific data and contributes to their improvement for the benefit of scientists in its member countries. In line with this mission, the Data Bank is a core centre of the International Network of Nuclear Reaction Data Centres (NRDC), which co-ordinates the worldwide collection, compilation and dissemination of nuclear reaction data. The NRDC network was established in 1976 from the earlier Four-Centres' Network created in 1966 by the United States, the NEA, the International Atomic Energy Agency (IAEA) and the former Soviet Union. Today, the NRDC is a worldwide co-operation network under the auspices of the IAEA, with 14 nuclear data centres from 8 countries and 2 international organisations belonging to the network. The main objective of the NRDC is to preserve, update and disseminate experimental nuclear reaction data that have been compiled for more than 40 years in a shared database (EXFOR). The EXFOR database contains basic nuclear data on low- to medium-energy experiments for incident neutron, photon and various charged-particle-induced reactions on a wide range of isotopes, natural elements and compounds. Today, with more than 140 000 data sets from approximately 20 000 experiments, EXFOR is by far the most important and complete experimental nuclear reaction database in the world and is widely used in the field of nuclear science and technology. The Data Bank is responsible for the collection and compilation of nuclear reaction data measured in its geographical area. Since 1966, the Data Bank has contributed around 5 000 experiments to the EXFOR database, and it continues to compile new data while maintaining the highest level of quality throughout the database. NRDC co-ordination meetings are held on a biennial basis. Recent meetings

  12. Passive containment system in high earthquake motion

    International Nuclear Information System (INIS)

    Kleimola, F.W.; Falls, O.B. Jr.

    1977-01-01

    High earthquake motion necessitates major design modifications in the complex of plant structures, systems and components in a nuclear power plant. Distinctive features imposed by seismic category, safety class and quality classification requirements for the high seismic ground acceleration loadings significantly reflect in plant costs. The design features in the Passive Containment System (PCS) responding to high earthquake ground motion are described

  13. Femtosecond two-dimensional spectroscopy of molecular motion in liquids

    NARCIS (Netherlands)

    Steffen, T; Duppen, K.

    1996-01-01

    Intermolecular motion in CS2 and benzene is investigated by femtosecond nonresonant four- and six-wave mixing. Impulsive stimulated six-wave mixing yields new information on dephasing of coherent nuclear motion, not accessible from four-wave mixing experiments. The results cannot be modeled by two

  14. Nuclear inertia for fission in a generalized cranking model

    International Nuclear Information System (INIS)

    Kunz, J.; Nix, J.R.

    1984-01-01

    The Inglis cranking model has been widely used to calculate the nuclear inertia associated with collective degrees of freedom. After the inclusion of pairing correlations, theoretical results obtained with the cranking model for nuclear rotations and γ-vibrations were in relatively good agreement with experimental data. Calculations of β-vibrational inertias were also performed in the cranking model for fission deformations. Theoretical results were several times the irrotational values and gave reasonable agreement with experimental spontaneous-fission lifetimes, although in one study a renormalization factor of 0.8 was required. However, as pointed out by many authors, the Inglis cranking model possesses two serious deficiencies. First, problems arise when the single-particle potential contains momentum-dependence terms. Second, in the limit of large pairing strength the inertia approaches zero instead of a finite (irrotational) limit. Alternative approaches to the cranking model which did not lead to such unacceptable results were developed by Migdal, Belyaev and Thouless and Valatin. They showed that these deficiencies of the cranking model are due to a lack of self-consistency, since the reaction of the mean field to the collective motion is neglected in the Inglis model. Previously we used their arguments and developed a generalized cranking model for stationary collective motion. Here it is shown how to develop a time-dependent formalism appropriate to β-vibrations and fission. 10 references

  15. Nuclear power plants. Guidelines to ensure quality of collected data on reliability

    International Nuclear Information System (INIS)

    1983-01-01

    This international standard lays down guidelines to be followed in the collection of data relative to nuclear power plants so as to ensure the reliability and completeness of the data and its insertion in a computerized system

  16. Non-Markovian nuclear dynamics

    International Nuclear Information System (INIS)

    Kolomietz, V.M.

    2011-01-01

    A prove of equations of motion for the nuclear shape variables which establish a direct connection of the memory effects with the dynamic distortion of the Fermi surface is suggested. The equations of motion for the nuclear Fermi liquid drop are derived from the collisional kinetic equation. In general, the corresponding equations are non-Markovian. The memory effects appear due to the Fermi surface distortions and depend on the relaxation time. The main purpose of the present work is to apply the non-Markovian dynamics to the description of the nuclear giant multipole resonances (GMR) and the large amplitude motion. We take also into consideration the random forces and concentrate on the formation of both the conservative and the friction forces to make more clear the memory effect on the nuclear dynamics. In this respect, the given approach represents an extension of the traditional liquid drop model (LDM) to the case of the nuclear Fermi liquid drop. In practical application, we pay close attention to the description of the descent of the nucleus from the fission barrier to the scission point.

  17. Design basis ground motion (Ss) required on new regulatory guide

    International Nuclear Information System (INIS)

    Kamae, Katsuhiro

    2013-01-01

    New regulatory guide is enforced on July 8. Here, it is introduced how the design basis ground motion (Ss) for seismic design of nuclear power reactor facilities was revised on the new guide. Ss is formulated as two types of earthquake ground motions, earthquake ground motions with site specific earthquake source and with no such specific source locations. The latter is going to be revised based on the recent observed near source ground motions. (author)

  18. Stochastic Effects; Application in Nuclear Physics

    International Nuclear Information System (INIS)

    Mazonka, O.

    2000-04-01

    Stochastic effects in nuclear physics refer to the study of the dynamics of nuclear systems evolving under stochastic equations of motion. In this dissertation we restrict our attention to classical scattering models. We begin with introduction of the model of nuclear dynamics and deterministic equations of evolution. We apply a Langevin approach - an additional property of the model, which reflect the statistical nature of low energy nuclear behaviour. We than concentrate our attention on the problem of calculating tails of distribution functions, which actually is the problem of calculating probabilities of rare outcomes. Two general strategies are proposed. Result and discussion follow. Finally in the appendix we consider stochastic effects in nonequilibrium systems. A few exactly solvable models are presented. For one model we show explicitly that stochastic behaviour in a microscopic description can lead to ordered collective effects on the macroscopic scale. Two others are solved to confirm the predictions of the fluctuation theorem. (author)

  19. Monitoring core barrel motion by neutron noise diagnostics

    International Nuclear Information System (INIS)

    Por, G.

    1985-08-01

    The core barrel motion is detected by ionization chambers located around the reactor vessel. The method is based on the measurement of the neutron flux fluctuations. Calculations to determine the direction and the size of the motion are discussed. The identification of core barrel motion and its connection with the error of one of the main circulating pumps in the Rheinsberg nuclear power plant are described. Core barrel motion of 10 Hz with an amplitude less than 50 μm could be diagnozed at the Paks-1 reactor using the Dutch high accuracy evaluation system. (V.N.)

  20. Survey of strong motion earthquake effects on thermal power plants in California with emphasis on piping systems. Volume 1, Main report

    International Nuclear Information System (INIS)

    Stevenson, J.D.

    1995-11-01

    Since 1982, there has been a major effort expended to evaluate the susceptibility of nuclear Power plant equipment to failure and significant damage during seismic events. This was done by making use of data on the performance of electrical and mechanical equipment in conventional power plants and other similar industrial facilities during strong motion earthquakes. This report is intended as an extension of the seismic experience data collection effort and a compilation of experience data specific to power plant piping and supports designed and constructed US power piping code requirements which have experienced strong motion earthquakes. Eight damaging (Richter Magnitude 7.7 to 5.5) California earthquakes and their effects on 8 power generating facilities in use natural gas and California were reviewed. All of these facilities were visited and evaluated. Seven fossel-fueled (dual use natural gas and oil) and one nuclear fueled plants consisting of a total of 36 individual boiler or reactor units were investigated. Peak horizontal ground accelerations that either had been recorded on site at these facilities or were considered applicable to these power plants on the basis of nearby recordings ranged between 0.20g and 0.5lg with strong motion durations which varied from 3.5 to 15 seconds. Most US nuclear power plants are designed for a safe shutdown earthquake peak ground acceleration equal to 0.20g or less with strong motion durations which vary from 10 to 15 seconds

  1. Seismic fragility analysis of a CANDU containment structure for near-fault ground motions

    International Nuclear Information System (INIS)

    Choi, In Kil; Choun, Young Sun; Seo, Jeong Moon; Ahn, Seong Moon

    2005-01-01

    The R. G. 1.60 spectrum used for the seismic design of Korean nuclear power plants provides a generally conservative design basis due to its broadband nature. A survey on some of the Quaternary fault segments near Korean nuclear power plants is ongoing. It is likely that these faults will be identified as active ones. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of the nuclear power plants located near these faults. The probability based scenario earthquakes were identified as near-field earthquakes. In general, the near-fault ground motion records exhibit a distinctive long period pulse like time history with very high peak velocities. These features are induced by the slip of the earthquake fault. Near-fault ground motions, which have caused much of the damage in recent major earthquakes, can be characterized by a pulse-like motion that exposes the structure to a high input energy at the beginning of the motion. It is necessary to estimate the near-fault ground motion effects on the nuclear power plant structures and components located near the faults. In this study, the seismic fragility analysis of a CANDU containment structure was performed based on the results of nonlinear dynamic time-history analyses

  2. The nuclear data collecting system designed with ARM and μC/OS-II

    International Nuclear Information System (INIS)

    Wang Chunsheng; Ma Yingjie; Han Feng

    2008-01-01

    Introduce a kind of nuclear data collecting system regarding ARM-μC/OS-II as the platform, gathering the GPS receiver in it. It was detailed to expatiated the key techniques of the multi-channel pulse amplitude analyzer, the interface design of LPC2148, a controller in ARM, and how to expand the RTOS and design applications on μC/OS-II. This system can communicate with the GPS-OEM module by the UART interface, collecting the GPS information synchronously as well as nuclear data. And then save and display them or pass them to the host computer by the USB interface. The embedded and Real-Time system, μC/OS-II build up the real-time and stability of the system and advance the integration. (authors)

  3. Nuclear event time histories and computed site transfer functions for locations in the Los Angeles region

    Science.gov (United States)

    Rogers, A.M.; Covington, P.A.; Park, R.B.; Borcherdt, R.D.; Perkins, D.M.

    1980-01-01

    This report presents a collection of Nevada Test Site (NTS) nuclear explosion recordings obtained at sites in the greater Los Angeles, Calif., region. The report includes ground velocity time histories, as well as, derived site transfer functions. These data have been collected as part of a study to evaluate the validity of using low-level ground motions to predict the frequency-dependent response of a site during an earthquake. For this study 19 nuclear events were recorded at 98 separate locations. Some of these sites have recorded more than one of the nuclear explosions, and, consequently, there are a total of 159, three-component station records. The location of all the recording sites are shown in figures 1–5, the station coordinates and abbreviations are given in table 1. The station addresses are listed in table 2, and the nuclear explosions that were recorded are listed in table 3. The recording sites were chosen on the basis of three criteria: (1) that the underlying geological conditions were representative of conditions over significant areas of the region, (2) that the site was the location of a strong-motion recording of the 1971 San Fernando earthquake, or (3) that more complete geographical coverage was required in that location.

  4. Prediction of ground motion from underground nuclear weapons tests as it relates to siting of a nuclear waste storage facility at NTS and compatibility with the weapons test program

    International Nuclear Information System (INIS)

    Vortman, L.J. IV.

    1980-04-01

    This report assumes reasonable criteria for NRC licensing of a nuclear waste storage facility at the Nevada Test Site where it would be exposed to ground motion from underground nuclear weapons tests. Prediction equations and their standard deviations have been determined from measurements on a number of nuclear weapons tests. The effect of various independent parameters on standard deviation is discussed. That the data sample is sufficiently large is shown by the fact that additional data have little effect on the standard deviation. It is also shown that coupling effects can be separated out of the other contributions to the standard deviation. An example, based on certain licensing assumptions, shows that it should be possible to have a nuclear waste storage facility in the vicinity of Timber Mountain which would be compatible with a 700 kt weapons test in the Buckboard Area if the facility were designed to withstand a peak vector acceleration of 0.75 g. The prediction equation is a log-log linear equation which predicts acceleration as a function of yield of an explosion and the distance from it

  5. 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)

  6. Ground motion input in seismic evaluation studies

    International Nuclear Information System (INIS)

    Sewell, R.T.; Wu, S.C.

    1996-07-01

    This report documents research pertaining to conservatism and variability in seismic risk estimates. Specifically, it examines whether or not artificial motions produce unrealistic evaluation demands, i.e., demands significantly inconsistent with those expected from real earthquake motions. To study these issues, two types of artificial motions are considered: (a) motions with smooth response spectra, and (b) motions with realistic variations in spectral amplitude across vibration frequency. For both types of artificial motion, time histories are generated to match target spectral shapes. For comparison, empirical motions representative of those that might result from strong earthquakes in the Eastern U.S. are also considered. The study findings suggest that artificial motions resulting from typical simulation approaches (aimed at matching a given target spectrum) are generally adequate and appropriate in representing the peak-response demands that may be induced in linear structures and equipment responding to real earthquake motions. Also, given similar input Fourier energies at high-frequencies, levels of input Fourier energy at low frequencies observed for artificial motions are substantially similar to those levels noted in real earthquake motions. In addition, the study reveals specific problems resulting from the application of Western U.S. type motions for seismic evaluation of Eastern U.S. nuclear power plants

  7. Analysis of the evolution of the collective dose in nuclear power plants in Spain

    International Nuclear Information System (INIS)

    Ponjuan Reyes, G.; Ruibia Rodiz, M. A. de la; Rosales Calvo, M.; Labarta Mancho, T.; Calavia Gimenez, I.

    2011-01-01

    This article presents an analysis of the evolution of occupational collective dose of the Spanish nuclear power planLs during the period 2000 - 2008 within the international context, by the Nuclear SafeLy Council (CSN) in order to have information contrasted to assessing the extent of applicaLion of the ALARA criLeria in the Spanish plants and identify areas of priority attention.

  8. On development and improvement of evaluation techniques for seismic ground motion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Issues regarding evaluation of active fault and ground motion for formulation of design basis ground motion (Ss) were prescribed in 'NSC seismic and tsunami safety reviewing manual' in 2012. Moreover, Nuclear Regulation Authority (NRA) is establishing the new seismic safety guideline. In this theme following four subjects were investigated to resolve the important problems for ground motion evaluation, (1) advanced evaluation of ground motion using fault model and uncertainty; (2) improving evaluation of ground motion using attenuation relation of response spectrum; (3) development of advanced and generic techniques for ground motion observation and observation tool in deep borehole; (4) improving the evaluation of site effect and seismic wave propagation characteristics. In addition as emergency requirements from NRA following two subjects were also investigated; (5) hazard evaluation development on fault displacement; (6) ground motion evaluation at near-by source location. Obtained results will be reflected not only in the domestic guideline established by NRA but in the national safety review and also in the safety standard guidelines of the International Atomic Energy Agency (IAEA) through its Extra-Budgetary Program (EBP), thereby contributing to technical cooperation in global nuclear seismic safety. (author)

  9. Zero-point motion in the bag description of the nucleon

    International Nuclear Information System (INIS)

    Brown, G.E.; Durso, J.W.; Johnson, M.B.

    1983-01-01

    In the bag model, confinement of quarks is accomplished by introduction of a boundary condition at some definite radius R, where the energy of the total system is a minimum. This minimum is, however, relatively shallow and energies for substantially different bag radii are not much larger than this minimum value. This indicates that the zero-point motion of the bag surface may be important. In this paper, quantization of the bag surface motion is carried out in a somewhat ad hoc fashion, modelled after the generator coordinate theory in nuclear physics. This procedure unifies a number of ideas previously in the literature; it stresses the anharmonicity of the collective motion. As in earlier treatments, the Roper resonance emerges as a breathing-mode type of excitation of the nucleon. The one- and two-pion decays of the Roper resonance are calculated and the widths are found to fall short of the empirical ones. It is pointed out, however, that decays involving intermediate states containing virtual rho-mesons will enhance the widths. Pion-nucleon scattering in the P 11 channel is constructed in our model and found to agree roughly with experiment. A crucial term in the driving force involves the pion coupling to the nucleon through a virtual rho-meson. With introduction of zero-point motion of the bag surface, the motion of 'bag radius' becomes dependent on precisely which moment of the radius is measured. Our development gives a model for cutting off smoothly the pion-exchange term in the nucleon-nucleon interaction. (orig.)

  10. Collective motion of predictive swarms.

    Directory of Open Access Journals (Sweden)

    Nathaniel Rupprecht

    Full Text Available Theoretical models of populations and swarms typically start with the assumption that the motion of agents is governed by the local stimuli. However, an intelligent agent, with some understanding of the laws that govern its habitat, can anticipate the future, and make predictions to gather resources more efficiently. Here we study a specific model of this kind, where agents aim to maximize their consumption of a diffusing resource, by attempting to predict the future of a resource field and the actions of other agents. Once the agents make a prediction, they are attracted to move towards regions that have, and will have, denser resources. We find that the further the agents attempt to see into the future, the more their attempts at prediction fail, and the less resources they consume. We also study the case where predictive agents compete against non-predictive agents and find the predictors perform better than the non-predictors only when their relative numbers are very small. We conclude that predictivity pays off either when the predictors do not see too far into the future or the number of predictors is small.

  11. Estimation of strong motions on free rock surface. Identification of soil structures and strong motions on free rock surface in Kashiwazaki-Kariwa nuclear power plant during the 2007 Niigataken Chuetsu-oki earthquake

    International Nuclear Information System (INIS)

    Saguchi, Koichiro; Masaki, Kazuaki; Irikura, Kojiro

    2009-01-01

    Very strong ground motions (maximum acceleration 993 cm/s 2 in the borehole seismometer point of -255m in depth) were observed in the Kashiwazaki Kariwa Nuclear Power Plant during the Niigataken Chuetsu-oki Earthquake on July 16, 2007. In this study, we tried to develop new method, which can simulate waveforms on free rock surface by using the bore hole records. We identified the underground structure model at the Service Hall from aftershock records observed in vertical array, using the simulated annealing method (Ingber(1989)). Based on numerical experiments it is identified that S-wave velocity and Q values of individual layers are inverted very well. Strong motion records of main shock observed by the bore hole seismometers were simulated by using one-dimensional multiple reflection method. In this study, non-linear effect is considered by introducing non-linear coefficient c(f) for under coming wave from surface. The maximum acceleration and phase characteristics in simulated waveforms are similar to the observed one. It means that our method is useful for simulate strong motion in non-linear region. Finally, strong motions on the free rock surface at the Service Hall during the main shock are simulated. The maximum acceleration of EW component on free rock surface is estimated to be 1,207 cm/s 2 . (author)

  12. 78 FR 56241 - Agency Information Collection Activities:

    Science.gov (United States)

    2013-09-12

    ...-0095] Agency Information Collection Activities: Notice of Appeal or Motion, Form I-290B; Revision of a... Collection (1) Type of Information Collection Request: Revision of a Currently Approved Collection. (2) Title of the Form/Collection: Notice of Appeal or Motion. (3) Agency form number, if any, and the...

  13. Engineering characterization of ground motion. Task II: Soil structure interaction effects on structural response

    Energy Technology Data Exchange (ETDEWEB)

    Luco, J E; Wong, H L [Structural and Earthquake Engineering Consultants, Inc., Sierra Madre, CA (United States); Chang, C -Y; Power, M S; Idriss, I M [Woodward-Clyde Consultants, Walnut Creek, CA (United States)

    1986-08-01

    This report presents the results of part of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this research program sponsored by the U.S. Nuclear Regulatory Commission (USNRC) is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study, which is presented in Vol. 1 of NUREG/CR-3805, developed a basis for selecting design response spectra taking into account the characteristics of free-field ground motion found to be significant in causing structural damage. Task II incorporates additional considerations of effects of spatial variations of ground motions and soil-structure interaction on foundation motions and structural response. The results of Task II are presented in Vols. 2 through of NUREG/CR-3805 as follows: Vol. 2 effects of ground motion characteristics on structural response considering localized structural nonlinearities and soil-structure interaction effects; Vol. 3 observational data on spatial variations of earthquake ground motions; Vol. 4 soil-structure interaction effects on structural response; and Vol. 5, summary based on Tasks I and II studies. This report presents the results of the Vol. 4 studies.

  14. A comparison of the different regulatory requirements of NPP in vertical ground motion

    International Nuclear Information System (INIS)

    Hou Chunlin; Pan Rong; Yang Yu; Wang Shuguo; Li Xiaojun

    2015-01-01

    Based on the importance of vertical motion in the nuclear power plants (NPPs) and equipment identification of seismic test, we summarize the existing laws and regulations cited by China's NPPs in the vertical seismic ground motion of the regulations. Then, according to the interpretation of various laws and regulations content, we may identified four vertical earthquake response spectrums. Finally, combined with the seismic safety requirements of China NPPs evaluation and the vertical seismic design of M310, EPR, AP1000 and CAP1400 pressurized water reactor, we explain that the vertical seismic ground motion selection should distinguish the effects between near field and far field earthquake, the existing regulations and specifications that China used are still required to further improve on the selection of vertical ground motion. The results of this study can provide reference for seismic design of China's nuclear power plant and nuclear safety review. (authors)

  15. Nuclear collective rotation in the SU3 model, 2

    International Nuclear Information System (INIS)

    Kinouchi, Shin-ichi; Kishimoto, Teruo; Kammuri, Tetsuo.

    1989-05-01

    The collective rotation of a nuclear system with the SU 3 Hamiltonian is described by the quantal dynamical nuclear field theory. An angular frequency in the Coriolis interaction of the driving Hamiltonian is replaced by a total angular momentum operator divided by the corresponding moment of inertia. We consider here the low spin states for a triaxial intrinsic configuration. The rotational effect is taken into account by using the effective quadrupole and angular momentum operators, whose expressions are different depending on whether they refer to the laboratory frame or the body-fixed one. Effective forms of the total Hamiltonian and the particle angular momentum are compared with the exact SU 3 energy and the rotor's angular momentum, respectively. In order to dissolve the disagreement for the effective operators, the perturbing interaction should be supplemented by a residual part of the quadrupole-quadrupole interaction, which restores the rotational invariance of the intrinsic Hamiltonian. (author)

  16. Boson mapping and the microscopic collective nuclear Hamiltonian

    International Nuclear Information System (INIS)

    Dobes, J.; Ivanova, S.P.; Dzholos, R.V.; Pedrosa, R.

    1990-01-01

    Starting with the mapping of the quadrupole collective states in the fermion space onto the boson space, the fermion nuclear problem is transformed into the boson one. The boson images of the bifermion operators and of the fermion Hamiltonian are found. Recurrence relations are used to obtain approximately the norm matrix which appears in the boson-fermion mapping. The resulting boson Hamiltonian contains terms which go beyond the ordinary SU(6) symmetry Hamiltonian of the interacting boson model. Calculations, however, suggest that on the phenomenological level the differences between the mapped Hamiltonian and the SU(6) Hamiltonian are not too important. 18 refs.; 2 figs

  17. Collective inertia in paired systems

    International Nuclear Information System (INIS)

    Arve, P.O.; Bertsch, G.F.; Michigan State Univ., East Lansing

    1988-01-01

    Two definitions of the collective inertia are examined. One of them was recently proposed and applied in a calculation of exotic radioactivity. The other expression is the Inglis cranking formula. It is shown that the new formula corresponds to rapid collective motion while the cranking corresponds to slow collective motion. It is also seen that the two forms of the inertia differ only in the choice of the collective momentum. (orig.)

  18. Nuclear magnetic resonance and relaxation studies of the structure and segmental motions of 4-vinyl-pyridinic polymers in solution

    International Nuclear Information System (INIS)

    Ghesquiere, Denis

    1978-01-01

    The poly 4-vinylpyridine, its quaternized products from HBr and n-alkyl-bromides, and its N-oxide form have been investigated by nuclear magnetic resonance of proton at 100 and 250 MHz and carbon-13 at 25.15 MHz, The 1 H and 13 C relaxation data of poly-vinylpyridine and its ionized form have been correlated with conformational calculations. They have been interpreted in terms of an isotropic motion of the macromolecular segments introducing a correlation times distribution and of an oscillation motion of the pyridyl groups. The same treatment have been used for the 13 C relaxation data of the poly 4- vinyl-pyridines quaternized at various rates by n-alkyl-bromides. The 13 C relaxation times in the side-chains have been interpreted first by semi-empirical equations assuming an exponential gradient of the diffusion coefficients along them, and also by a Monte Carlo simulation of the motions. The results have shown that the quaternization induces a strong rigidity of the macromolecular backbone and that the dominant effect is the electrostatic interactions. On the other hand it seems that the motion of pyridyl rings is not affected. Moreover we have found a range of oscillation amplitudes in agreement with conformational energy calculations and the results obtained from a conformational study of the poly 4-vinylpyridine N-oxide by 1 H and 13 C NMR contact shifts induced by Ni II paramagnetic ions. (author) [fr

  19. Effect of a neutron skin on collective dipoles modes in nuclei

    International Nuclear Information System (INIS)

    Warner, D.D.; Van Isacker, P.; Nagarajan, M.A.

    1992-01-01

    One of the principal motivations for accelerated radioactive beams is to probe nuclear structure at the limits of nuclear stability. For neutron-rich nuclei, an indication of the new phenomena which may occur has already appeared, in the guise of the neutron halo discovered in very light nuclei. More generally, a steadily increasing neutron skin thickness is expected as the neutron excess increases. The presence of such a mantle of dominantly neutron matter will then particularly affect the properties of collective modes involving the out-of-phase motion of neutrons and protons. This paper explores the effect of the neutron skin thickness on the isovector M1 and E1 modes in medium and heavy mass nuclei. A simple model is used, couched in terms of classical oscillations of neutron and proton densities. The treatment includes the open-quotes pygmyclose quotes E1 mode, which corresponds to motion of the core against the loosely-bound neutrons in the mantle and predicts a significant lowering of this mode, even at relatively modest values of the skin thickness

  20. Proceedings of the 32nd International Workshop on Nuclear Theory (IWNT-32)

    International Nuclear Information System (INIS)

    Georgieva, A. I.; Minkov, N.

    2013-01-01

    The main topics of the 2013 Workshop were: Nuclear structure and reactions; Symmetries and dynamics; Collective and intrinsic motions of nuclei; Exotic nuclei; Few-body and many-fermion systems; Nuclear astrophysics and related topics. Most of them are part of the NTL’s program for basic nuclear physics research. However, they were kept open for participants from a much broader area of interests bridging with novel experimental developments, interdisciplinary topics related to nuclear structure and reactions, as well as, nuclear physics applications like nuclear safety. For the first time we had a participant from the Kozloduy Nuclear Power Plant as well as a lecturer giving a talk on nuclear reactor safety. The Workshop was attended by 42 participants (including the organizers) from India, Italy, Germany, UK, Hungary, Poland, Spain, Russia, Kazakhstan, Uzbekistan, South Africa, USA and Bulgaria. The scientific program contained totally 30 oral talks and 1 poster

  1. Dynamical symmetries of molecular states in atomic, nuclear and hadron physics

    International Nuclear Information System (INIS)

    Iachello, F.; Cseh, J.; Levai, G.

    1995-01-01

    The algebraic description of dipole degrees of freedom is discussed. These degrees of freedom are relevant to two and few-body systems, as well as in the collective motion of many-body systems. Applications to molecular, nuclear and hadron spectroscopy are presented. Different internal degrees of freedom can also be coupled to the spatial ones, leading to realistic models of several complex systems. (author)

  2. Development of an Embedded Solar Tracking System with LabVIEW Motion Control

    International Nuclear Information System (INIS)

    Oh, Seung Jin; Hyun, Jun Ho; Oh, Won Jong; Kim, Yeong Min; Lee, Yoon Joon; Chun, Won Gee

    2010-01-01

    Motion control is a sub-field of automation, in which the position and/or velocity of machines are controlled using some type of device such as a hydraulic pump, linear actuator, or an electric motor. The motion control is widely used in the packaging, printing, textile, semiconductor production, and power plants. National Instruments LabVIEW is a graphical programming language that has its roots in automation control and data acquisition. Its graphical representation, similar to a process flow diagram, was created to provide an intuitive programming environment for scientist and engineers. Crystal River Nuclear Plant engineers developed automated testing system of nuclear plant control modules in an aging nuclear power plant using LabVIEW to improve performance and reliability and reduce cost. In this study, an embedded two-axis solar tracking system was developed using LabVIEW motion control module

  3. Molecular structure and motion in zero field magnetic resonance

    International Nuclear Information System (INIS)

    Jarvie, T.P.

    1989-10-01

    Zero field magnetic resonance is well suited for the determination of molecular structure and the study of motion in disordered materials. Experiments performed in zero applied magnetic field avoid the anisotropic broadening in high field nuclear magnetic resonance (NMR) experiments. As a result, molecular structure and subtle effects of motion are more readily observed

  4. Macroscopic dynamics of thermal nuclear excitations

    International Nuclear Information System (INIS)

    Bastrukov, S.I.; Deak, F.; Kiss, A.; Seres, Z.

    1989-11-01

    The concept of kinetic temperature as a local dynamical variable of thermal nuclear collective motion is formulated using long-mean-free-path approach based on the Landau-Vlasov kinetic equation. In the Fermi drop model the thermal fluid dynamics of the spherical nucleus is analyzed. It is shown that in a compressible Fermi liquid the temperature pulses propagate in the form of spherical wave in phase with the acoustic wave. The thermal and compressional excitations are caused by the isotropic harmonic oscillations of the Fermi sphere in momentum space. (author) 25 refs.; 2 figs

  5. Activities on collection, evaluation and dissemination of non-neutron nuclear data in the USSR

    International Nuclear Information System (INIS)

    Grigor'yan, Yu.I.; Ignatochkin, A.E.; Sokolovskij, L.L.; Chukreev, F.E.

    1976-01-01

    The article describes the present status of collection, evaluation and dissemination of non-neutron nuclear data by the Centre for Data on the Structure of the Atomic Nucleus and Nuclear Reactions, USSR State Committee on the utilization of Atomic Energy. The structure of the Centre itself, its computer facilities and its co-operation with outside organizations are indicated and its functions and plans of activity are considered. (author)

  6. Energetic M1 transitions as a probe of nuclear collectivity at high temperatures

    International Nuclear Information System (INIS)

    Baktash, C.

    1987-01-01

    At ORNL, we have recently utilized the Spin Spectrometer setup to investigate the differential effects of increasing spin and excitation energy on nuclear shape and collectivity in 158 Yb. Along the yrast line of this and other N = 88 nuclei, weakly prolate shapes gradually give way to triaxial, and then finally to non-collective oblate shapes as the spin approaches 40 h-bar. However, above the yrast line, large deformation and collectivity once again sets in. This is evidenced by the emergence of a broad quadrupole structure (E/sub γ/ ≅ 1.2 MeV) in the continuum gamma-ray spectra that grows with increasing temperature. The short (sub ps) lifetimes of these transitions attest to the collective nature of these structures. The emergence and growth of the quadrupole structure at high excitation energies is closely correlated with the appearance of energetic (E/sub γ/ ≅ 2.5 MeV), fast M1 transitions which form another broad structure in the continuum spectra. From the centroid of the M1 bump, a quadrupole deformation parameter of 0.35 is inferred. Because of this sensitivity, these energetic M1 transitions provide a unique probe of nuclear shape in the excitation energy range of ≅ 3 to 10 MeV. 6 refs., 2 figs

  7. Description of ground motion data processing codes: Volume 3

    International Nuclear Information System (INIS)

    Sanders, M.L.

    1988-02-01

    Data processing codes developed to process ground motion at the Nevada Test Site for the Weapons Test Seismic Investigations Project are used today as part of the program to process ground motion records for the Nevada Nuclear Waste Storage Investigations Project. The work contained in this report documents and lists codes and verifies the ''PSRV'' code. 39 figs

  8. Collective states of nonspherical deformable even--even nuclei

    International Nuclear Information System (INIS)

    Tartakovskii, V.K.

    1989-01-01

    A more correct method, as compared with some earlier studies, of finding the wave functions and corresponding energies of longitudinal quadrupole vibrations of nonspherical even--even nuclei is proposed. The wave functions and energies of collective motions in nuclei have been obtained in explicit form for a number of dependences of the potential energy of longitudinal vibrations V(β), including the dependence V(β), not previously used, of the most general form. Explicit dependences of the potential energy of transverse vibrations and the corresponding wave functions and eigenvalues for nuclear states with zero spins are proposed

  9. Microscopic nuclear structure models and methods: chiral symmetry, wobbling motion and γ –bands

    International Nuclear Information System (INIS)

    Sheikh, Javid A; Bhat, Gowhar H; Dar, Waheed A; Jehangir, Sheikh; Ganai, Prince A

    2016-01-01

    A systematic investigation of the nuclear observables related to the triaxial degree of freedom is presented using the multi-quasiparticle triaxial projected shell model (TPSM) approach. These properties correspond to the observation of γ -bands, chiral doublet bands and the wobbling mode. In the TPSM approach, γ -bands are built on each quasiparticle configuration and it is demonstrated that some observations in high-spin spectroscopy that have remained unresolved for quite some time could be explained by considering γ -bands based on two-quasiparticle configurations. It is shown in some Ce-, Nd- and Ge-isotopes that the two observed aligned or s-bands originate from the same intrinsic configuration with one of them as the γ -band based on a two-quasiparticle configuration. In the present work, we have also performed a detailed study of γ -bands observed up to the highest spin in dysposium, hafnium, mercury and uranium isotopes. Furthermore, several measurements related to chiral symmetry breaking and wobbling motion have been reported recently. These phenomena, which are possible only for triaxial nuclei, have been investigated using the TPSM approach. It is shown that doublet bands observed in lighter odd–odd Cs-isotopes can be considered as candidates for chiral symmetry breaking. Transverse wobbling motion recently observed in 135 Pr has also been investigated and it is shown that TPSM approach provides a reasonable description of the measured properties. (invited comment)

  10. Effect of earthquake and tsunami. Ground motion and tsunami observed at nuclear power station

    International Nuclear Information System (INIS)

    Hijikata, Katsuichirou

    2012-01-01

    Fukushima Daiichi and Daini Nuclear Power Stations (NPSs) were struck by the earthquake off the pacific coast in the Tohoku District, which occurred at 14:46 on March 11, 2011. Afterwards, tsunamis struck the Tohoku District. In terms of the earthquake observed at the Fukushima NPSs, the acceleration response spectra of the earthquake movement observed on the basic board of reactor buildings exceeded the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss for partial periodic bands at the Fukushima Daiichi NPS. As for the Fukushima Daini NPS, the acceleration response spectra of the earthquake movement observed on the basic board of the reactor buildings was below the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss. Areas inundated by Tsunami at each NPS were investigated and tsunami inversion analysis was made to build tsunami source model to reproduce tide record, tsunami height, crustal movement and inundated area, based on tsunami observation records in the wide areas from Hokkaido to Chiba prefectures. Tsunami heights of Fukushima Daiichi and Daini NPSs were recalculated as O.P. +13m and +9m respectively and tsunami peak height difference was attributed to the extent of superposition of tsunami waves of tsunami earthquake type of wave source in the area along interplane trench off the coast in the Fukushima prefecture and interplane earthquake type of wave source in rather deep interplate area off the coast in the Miyagi prefecture. (T. Tanaka)

  11. Nuclear Engineering Committee KTA. A collection of definitions as of January 16, 1987

    International Nuclear Information System (INIS)

    Riedel, U.

    1987-01-01

    The collection of definitions mainly comprises terms which are laid down in the recommendations of the Nuclear Engineering Committee (KTA) or in overriding regulations and specifications. The collection aims at a KTA-standardized use of terms and at the avoidance of groundless divergences. The compiled definitions are followed by a list of the sources considered, namely laws, ordinances, administrative recommendations, KTA regulations as well as other recommendations and standards. (orig./HSCH) [de

  12. Collective many-body dynamics in the vicinity of nuclear driplines

    International Nuclear Information System (INIS)

    Volya, Alexander; Zelevinsky, Vladimir

    2007-01-01

    The Continuum Shell Model is a powerful theoretical tool for analysis of many-body dynamics embedded in the continuum. Here we formulate the method and use an example of a realistic shell model calculation for oxygen isotopes to demonstrate the seamless transition from bound states to resonances and cross sections in continuum within the same framework. The coupled dynamics of intrinsic states and continuum is traced further to the regime of continuum dominance that implies the decay width collectivization and onset of super-radiance. The coexistence and interplay of internal collective motion, such as giant resonances, and decay are of particular interest. Schematic and realistic calculations illustrate changes in the strength distribution and the natural appearance of the so-called pygmy mode

  13. Effects of ship motions on laminar flow in tubes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, B.H., E-mail: yanbh1986@163.co [Department of Nuclear Science and Engineering, Naval University of Engineering, 717 Jiefang Street, Wuhan 430033 (China); Yu, L. [Department of Nuclear Science and Engineering, Naval University of Engineering, 717 Jiefang Street, Wuhan 430033 (China); Yang, Y.H. [School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2010-01-15

    The thermal-hydraulics of barge-mounted floating nuclear desalination plants is the incentive for this study. Laminar flow in tubes in heaving motion is modeled. The friction factor and heat transfer coefficient are obtained. All the equations of laminar flow in steady state are applicable for heeling motion. The effect of ship motions on the laminar developing region is also analyzed. The ship motions can weaken the boundary layer in the laminar developing region and strengthen the laminar frictional resistance. The effect of ship motions on the instability of laminar flow is also investigated. The ship motions do not affect the instability point, but they can shorten the distance between the instability point and the transition point, and cause the transition from laminar flow to turbulent flow to occur earlier.

  14. Nuclear energy: technology, safety, ecology, economy, management. The I All-Russian scientific-practical conference of young nuclear scientists of Siberia. Collection of scientific papers

    International Nuclear Information System (INIS)

    2010-01-01

    Collection of research papers I All-Russian scientific-practical conference of young nuclear scientists in Siberia, held 19-25 September 2010 in Tomsk, is presented. The edition contains material on a wide range of research scientists-economists, professors, graduate students and young scientists, and school children of Tomsk, Seversk, and several other Russian cities on the technology, security, ecology, economics, management in the nuclear power industry. Discussion of the presented research was conducted on sections: 1. Technological support for the nuclear fuel cycle, 2. Nuclear non-proliferation and environmental safety of the nuclear fuel cycle, 3. Energy: Present and Future 4. It all starts with an idea [ru

  15. String-like cooperative motion in homogeneous melting.

    Science.gov (United States)

    Zhang, Hao; Khalkhali, Mohammad; Liu, Qingxia; Douglas, Jack F

    2013-03-28

    Despite the fundamental nature and practical importance of melting, there is still no generally accepted theory of this ubiquitous phenomenon. Even the earliest simulations of melting of hard discs by Alder and Wainwright indicated the active role of collective atomic motion in melting and here we utilize molecular dynamics simulation to determine whether these correlated motions are similar to those found in recent studies of glass-forming (GF) liquids and other condensed, strongly interacting, particle systems. We indeed find string-like collective atomic motion in our simulations of "superheated" Ni crystals, but other observations indicate significant differences from GF liquids. For example, we observe neither stretched exponential structural relaxation, nor any decoupling phenomenon, while we do find a boson peak, findings that have strong implications for understanding the physical origin of these universal properties of GF liquids. Our simulations also provide a novel view of "homogeneous" melting in which a small concentration of interstitial defects exerts a powerful effect on the crystal stability through their initiation and propagation of collective atomic motion. These relatively rare point defects are found to propagate down the strings like solitons, driving the collective motion. Crystal integrity remains preserved when the permutational atomic motions take the form of ring-like atomic exchanges, but a topological transition occurs at higher temperatures where the rings open to form linear chains similar in geometrical form and length distribution to the strings of GF liquids. The local symmetry breaking effect of the open strings apparently destabilizes the local lattice structure and precipitates crystal melting. The crystal defects are thus not static entities under dynamic conditions, such as elevated temperatures or material loading, but rather are active agents exhibiting a rich nonlinear dynamics that is not addressed in conventional "static

  16. Inherent noise can facilitate coherence in collective swarm motion

    KAUST Repository

    Yates, C. A.; Erban, R.; Escudero, C.; Couzin, I. D.; Buhl, J.; Kevrekidis, I. G.; Maini, P. K.; Sumpter, D. J. T.

    2009-01-01

    Among the most striking aspects of the movement of many animal groups are their sudden coherent changes in direction. Recent observations of locusts and starlings have shown that this directional switching is an intrinsic property of their motion. Similar direction switches are seen in self-propelled particle and other models of group motion. Comprehending the factors that determine such switches is key to understanding the movement of these groups. Here, we adopt a coarse-grained approach to the study of directional switching in a self-propelled particle model assuming an underlying one-dimensional Fokker-Planck equation for the mean velocity of the particles. We continue with this assumption in analyzing experimental data on locusts and use a similar systematic Fokker-Planck equation coefficient estimation approach to extract the relevant information for the assumed Fokker-Planck equation underlying that experimental data. In the experiment itself the motion of groups of 5 to 100 locust nymphs was investigated in a homogeneous laboratory environment, helping us to establish the intrinsic dynamics of locust marching bands. We determine the mean time between direction switches as a function of group density for the experimental data and the self-propelled particle model. This systematic approach allows us to identify key differences between the experimental data and the model, revealing that individual locusts appear to increase the randomness of their movements in response to a loss of alignment by the group. We give a quantitative description of how locusts use noise to maintain swarm alignment. We discuss further how properties of individual animal behavior, inferred by using the Fokker-Planck equation coefficient estimation approach, can be implemented in the self-propelled particle model to replicate qualitatively the group level dynamics seen in the experimental data.

  17. Inherent noise can facilitate coherence in collective swarm motion

    KAUST Repository

    Yates, C. A.

    2009-03-31

    Among the most striking aspects of the movement of many animal groups are their sudden coherent changes in direction. Recent observations of locusts and starlings have shown that this directional switching is an intrinsic property of their motion. Similar direction switches are seen in self-propelled particle and other models of group motion. Comprehending the factors that determine such switches is key to understanding the movement of these groups. Here, we adopt a coarse-grained approach to the study of directional switching in a self-propelled particle model assuming an underlying one-dimensional Fokker-Planck equation for the mean velocity of the particles. We continue with this assumption in analyzing experimental data on locusts and use a similar systematic Fokker-Planck equation coefficient estimation approach to extract the relevant information for the assumed Fokker-Planck equation underlying that experimental data. In the experiment itself the motion of groups of 5 to 100 locust nymphs was investigated in a homogeneous laboratory environment, helping us to establish the intrinsic dynamics of locust marching bands. We determine the mean time between direction switches as a function of group density for the experimental data and the self-propelled particle model. This systematic approach allows us to identify key differences between the experimental data and the model, revealing that individual locusts appear to increase the randomness of their movements in response to a loss of alignment by the group. We give a quantitative description of how locusts use noise to maintain swarm alignment. We discuss further how properties of individual animal behavior, inferred by using the Fokker-Planck equation coefficient estimation approach, can be implemented in the self-propelled particle model to replicate qualitatively the group level dynamics seen in the experimental data.

  18. Rotational motion in nuclei

    International Nuclear Information System (INIS)

    Bohr, A.

    1976-01-01

    Nuclear structure theories are reviewed concerned with nuclei rotational motion. The development of the deformed nucleus model facilitated a discovery of rotational spectra of nuclei. Comprehensive verification of the rotational scheme and a successful classification of corresponding spectra stimulated investigations of the rotational movement dynamics. Values of nuclear moments of inertia proved to fall between two marginal values corresponding to rotation of a solid and hydrodynamic pattern of an unrotating flow, respectively. The discovery of governing role of the deformation and a degree of a symmetry violence for determining rotational degrees of freedon is pointed out to pave the way for generalization of the rotational spectra

  19. Low work-function thermionic emission and orbital-motion-limited ion collection at bare-tether cathodic contact

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xin, E-mail: xin.chen@upm.es; Sanmartín, J. R., E-mail: juanr.sanmartin@upm.es [Departamento de Física Aplicada, Escuela Técnica Superior de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Plaza Cardenal Cisneros, 3, 28040 Madrid (Spain)

    2015-05-15

    With a thin coating of low-work-function material, thermionic emission in the cathodic segment of bare tethers might be much greater than orbital-motion-limited (OML) ion collection current. The space charge of the emitted electrons decreases the electric field that accelerates them outwards, and could even reverse it for high enough emission, producing a potential hollow. In this work, at the conditions of high bias and relatively low emission that make the potential monotonic, an asymptotic analysis is carried out, extending the OML ion-collection analysis to investigate the probe response due to electrons emitted by the negatively biased cylindrical probe. At given emission, the space charge effect from emitted electrons increases with decreasing magnitude of negative probe bias. Although emitted electrons present negligible space charge far away from the probe, their effect cannot be neglected in the global analysis for the sheath structure and two thin layers in between sheath and the quasineutral region. The space-charge-limited condition is located. It is found that thermionic emission increases the range of probe radius for OML validity and is greatly more effective than ion collection for cathodic contact of tethers.

  20. Nuclear collective flow from gaussian fits to triple differential distributions

    International Nuclear Information System (INIS)

    Gosset, J.; Demoulins, M.; Babinet, R.; Cavata, C.; Fanet, H.; L'Hote, D.; Lucas, B.; Poitou, J.; Valette, O.; Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Dupieux, P.; Fraysse, L.; Marroncle, J.; Montarou, G.; Parizet, M.J.; Qassoud, D.; Rahmani, A.; Brochard, F.; Gorodetzky, P.; Racca, C.

    1990-01-01

    In order to study the nuclear collective flow, the triple differential momentum distributions of charged baryons are fitted to a simple anisotropic gaussian distribution, within an acceptance which removes most of the spectator contribution. The adjusted flow angle and aspect ratios are corrected for systematic errors in the determination of the reaction plane. This method has been tested with Monte Carlo simulations and applied to experimental results and intranuclear cascade simulations of argon-nucleus collisions at 400 MeV per nucleon. (orig.)

  1. Search for nuclear excitation by laser-driven electron motion

    International Nuclear Information System (INIS)

    Bounds, J.A.; Dyer, P.

    1992-01-01

    It has been proposed that a nucleus may be excited by first exciting the atom's electrons with UV photons. The incident photons couple to the electrons, which would then couple via a virtual photon to the nucleus. As a test case, experiments with 235 U have been performed. A pulsed infrared laser produces an atomic vapor of 235 U which is then bombarded by a high-brightness UV laser beam. The resulting ions are collected. The first excited nuclear state of 235 U has a 26-min half-life and decays by internal conversion, resulting in emission of an atomic electron. These conversion electrons are detected by a channel electron multiplier. An upper limit of 4.0x10 -5 has been obtained for the probability of exciting the nucleus of a 235 U atom that is in the 248-nm UV beam for 700 fs at an irradiance in the range of 1.0x10 15 to 2.5x10 15 W/cm 2

  2. Studies of Fluctuation Processes in Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ayik, Sakir [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics

    2016-04-14

    The standard one-body transport approaches have been extensively applied to investigate heavy-ion collision dynamics at low and intermediate energies. At low energies the approach is the mean-field description of the time-dependent Hartree-Fock (TDHF) theory. At intermediate energies the approach is extended by including a collision term, and its application has been carried out mostly in the semi-classical framework of the Boltzmann-Uhling-Uhlenbeck (BUU) model. The standard transport models provide a good understanding of the average properties of the collision dynamics in terms of the effective interactions in both low and intermediate energies. However, the standard models are inadequate for describing the fluctuation dynamics of collective motion at low energies and disassembling of the nuclear system into fragments at intermediate energies resulting from the growth of density fluctuations in the spinodal region. Our tasks have been to improve the standard transport approaches by incorporating fluctuation mechanisms into the description. There are mainly two different mechanisms for fluctuations: (i) Collisional fluctuations generated by binary nucleon collisions, which provide the dominant mechanism at intermediate energies, and (ii) One-body mechanism or mean-field fluctuations, which is the dominant mechanism at low energies. In the first part of our project, the PI extended the standard transport model at intermediate energies by incorporating collisional mechanism according to the “Generalized Langevin Description” of Mori formalism. The PI and his collaborators carried out a number of applications for describing dynamical mechanism of nuclear multi fragmentations, and nuclear collective response in the semi-classical framework of the approach, which is known as the Boltzmann-Langevin model. In the second part of the project, we considered dynamical description at low energies. Because of the effective Pauli blocking, the collisional dissipation and

  3. Collecting and recirculating condensate in a nuclear reactor containment

    International Nuclear Information System (INIS)

    Schultz, T.L.

    1993-01-01

    An arrangement passively cools a nuclear reactor in the event of an emergency, condensing and recycling vaporized cooling water. The reactor is surrounded by a containment structure and has a storage tank for cooling liquid, such as water, vented to the containment structure by a port. The storage tank preferably is located inside the containment structure and is thermally coupleable to the reactor, e.g. by a heat exchanger, such that water in the storage tank is boiled off to carry away heat energy. The water is released as a vapor (steam) and condenses on the cooler interior surfaces of the containment structure. The condensed water flows downwardly due to gravity and is collected and routed back to the storage tank. One or more gutters are disposed along the interior wall of the containment structure for collecting the condensate from the wall. Piping is provided for communicating the condensate from the gutters to the storage tank. 3 figures

  4. Collecting and recirculating condensate in a nuclear reactor containment

    Science.gov (United States)

    Schultz, Terry L.

    1993-01-01

    An arrangement passively cools a nuclear reactor in the event of an emergency, condensing and recycling vaporized cooling water. The reactor is surrounded by a containment structure and has a storage tank for cooling liquid, such as water, vented to the containment structure by a port. The storage tank preferably is located inside the containment structure and is thermally coupleable to the reactor, e.g. by a heat exchanger, such that water in the storage tank is boiled off to carry away heat energy. The water is released as a vapor (steam) and condenses on the cooler interior surfaces of the containment structure. The condensed water flows downwardly due to gravity and is collected and routed back to the storage tank. One or more gutters are disposed along the interior wall of the containment structure for collecting the condensate from the wall. Piping is provided for communicating the condensate from the gutters to the storage tank.

  5. Collective motion and the generator coordinate method

    International Nuclear Information System (INIS)

    Passos, E.J.V. de

    1981-01-01

    The generator coordinate method is used to construct a collective subspace of the many-body Hylbert space. The construction is based on the analysis of the properties of the overlaps of the generator states. Some well-known misbehaviours of the generator coordinate weight functions are clearly identified as of kinematical origin. A standard orthonormal representation in the collective subspace is introduced which eliminates them. It is also indicated how appropriate collective dynamical variables can be defined a posteriori. To illustrate the properties of the collective subspaces applications are made to a) translational invariant overlap kernels b) to one and two-conjugate parameter families of generator states. (Author) [pt

  6. Coupled quantum-classical method for long range charge transfer: relevance of the nuclear motion to the quantum electron dynamics

    International Nuclear Information System (INIS)

    Da Silva, Robson; Hoff, Diego A; Rego, Luis G C

    2015-01-01

    Charge and excitonic-energy transfer phenomena are fundamental for energy conversion in solar cells as well as artificial photosynthesis. Currently, much interest is being paid to light-harvesting and energy transduction processes in supramolecular structures, where nuclear dynamics has a major influence on electronic quantum dynamics. For this reason, the simulation of long range electron transfer in supramolecular structures, under environmental conditions described within an atomistic framework, has been a difficult problem to study. This work describes a coupled quantum mechanics/molecular mechanics method that aims at describing long range charge transfer processes in supramolecular systems, taking into account the atomistic details of large molecular structures, the underlying nuclear motion, and environmental effects. The method is applied to investigate the relevance of electron–nuclei interaction on the mechanisms for photo-induced electron–hole pair separation in dye-sensitized interfaces as well as electronic dynamics in molecular structures. (paper)

  7. Collective effects on transport coefficients of relativistic nuclear matter. Pt. 2

    International Nuclear Information System (INIS)

    Mornas, L.

    1993-04-01

    The transport coefficients (thermal conductivity, shear and bulk viscosities) of symmetric nuclear matter and neutron matter are calculated in the Walecka model with a Boltzmann-Uehling-Uhlenbeck collision term by means of a Chapman-Enskog expansion in first order. The order of magnitude of the influence of collective effects induced by the presence of the mean σ and ω fields on these coefficients is evaluated. (orig.). 9 figs

  8. Mapping quadrupole collectivity in the Cd isotopes: The breakdown of harmonic vibrational motion

    Science.gov (United States)

    Garrett, P. E.; Green, K. L.; Bangay, J.; Varela, A. Diaz; Sumithrarachchi, C. S.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D. S.; Bianco, L.; Colosimo, S.; Cross, D. S.; Demand, G. A.; Finlay, P.; Garnsworthy, A. B.; Grinyer, G. F.; Hackman, G.; Kulp, W. D.; Leach, K. G.; Morton, A. C.; Orce, J. N.; Pearson, C. J.; Phillips, A. A.; Schumaker, M. A.; Svensson, C. E.; Triambak, S.; Wong, J.; Wood, J. L.; Yates, S. W.

    2011-10-01

    The stable Cd isotopes have long been used as paradigms for spherical vibrational motion. Extensive investigations with in-beam γ spectroscopy have resulted in very-well-established level schemes, including many lifetimes or lifetime limits. A programme has been initiated to complement these studies with very-high-statistics β decay using the 8π spectrometer at the TRIUMF radioactive beam facility. The decays of 112In and 112Ag have been studied with an emphasis on the observation of, or the placement of stringent limits on, low-energy branches between potential multi-phonon levels. A lack of suitable 0+ or 2+ three-phonon candidates has been revealed. Further, the sum of the B(E2) strength from spin 0+ and 2+ states up to 3 MeV in excitation energy to the assigned two-phonon levels falls far short of the harmonic-vibrational expectations. This lack of strength points to the failing of collective models based on vibrational phonon structures.

  9. Motion as a phenotype: the use of live-cell imaging and machine visual screening to characterize transcription-dependent chromosome dynamics

    Directory of Open Access Journals (Sweden)

    Silver Pamela A

    2006-04-01

    Full Text Available Abstract Background Gene transcriptional activity is well correlated with intra-nuclear position, especially relative to the nuclear periphery, which is a region classically associated with gene silencing. Recently however, actively transcribed genes have also been found localized to the nuclear periphery in the yeast Saccharomyces cerevisiae. When genes are activated, they become associated with the nuclear pore complex (NPC at the nuclear envelope. Furthermore, chromosomes are not static structures, but exhibit constrained diffusion in real-time, live-cell studies of particular loci. The relationship of chromosome motion with transcriptional activation and active-gene recruitment to the nuclear periphery has not yet been investigated. Results We have generated a yeast strain that enables us to observe the motion of the galactose-inducible GAL gene locus relative to the nuclear periphery in real-time under transcriptionally active and repressed conditions. Using segmented geometric particle tracking, we show that the repressed GAL locus undergoes constrained diffusive movement, and that transcriptional induction with galactose is associated with an enrichment in cells with GAL loci that are both associated with the nuclear periphery and much more constrained in their movement. Furthermore, we report that the mRNA export factor Sac3 is involved in this galactose-induced enrichment of GAL loci at the nuclear periphery. In parallel, using a novel machine visual screening technique, we find that the motion of constrained GAL loci correlates with the motion of the cognate nuclei in galactose-induced cells. Conclusion Transcriptional activation of the GAL genes is associated with their tethering and motion constraint at the nuclear periphery. We describe a model of gene recruitment to the nuclear periphery involving gene diffusion and the mRNA export factor Sac3 that can be used as a framework for further experimentation. In addition, we applied to

  10. Emergence of coherent motion in aggregates of motile coupled maps

    International Nuclear Information System (INIS)

    Garcia Cantu Ros, A.; Antonopoulos, Ch.G.; Basios, V.

    2011-01-01

    Highlights: → A minimal model of motile particles with adjustable intrinsic steering is presented. → Collective motion emerges due to self-adaptation of each particle's intrinsic state. → Adaptation is achieved by a map which behavior ranges from periodic to chaotic. → Higher cohesion occurs in a balanced combination of ordered and chaotic motion. → Exhibits an abrupt change in degree of coherence as a function of particle density. - Abstract: In this paper we study the emergence of coherence in collective motion described by a system of interacting motiles endowed with an inner, adaptative, steering mechanism. By means of a nonlinear parametric coupling, the system elements are able to swing along the route to chaos. Thereby, each motile can display different types of behavior, i.e. from ordered to fully erratic motion, accordingly with its surrounding conditions. The appearance of patterns of collective motion is shown to be related to the emergence of interparticle synchronization and the degree of coherence of motion is quantified by means of a graph representation. The effects related to the density of particles and to interparticle distances are explored. It is shown that the higher degrees of coherence and group cohesion are attained when the system elements display a combination of ordered and chaotic behaviors, which emerges from a collective self-organization process.

  11. Operational data collection and analysis for nuclear plant life extension

    International Nuclear Information System (INIS)

    DuCharme, A.R.; Berg, R.M.; Bailey, T.L.

    1989-01-01

    This paper describes initial work undertaken by the US Department of Energy, through Sandia National Laboratories in Albuquerque, New Mexico, to define the operational data necessary for support of nuclear plant life extension (PLEX) programs. This work is being performed in coordination with the Working Group on Plant Life Extension of the US Nuclear Management and Resources Council. The intent of the effort is to use results gained initially from pilot PLEX programs a US BWR and a US PWR to build towards the use of ''PLEX indicators'' by which a plant's readiness for successful life extension can be measured. Another objective of the study was to examine chemistry data in detail to determine how well US plants are collecting, preserving, and trending the chemistry data that is important to PLEX. The methods used to disseminate this data to outside agencies and other utilities were studied. Finally, an analysis was made to determine additional chemistry data needed to support PLEX

  12. Nuclear collective flow from gaussian fits to triple differential distributions

    International Nuclear Information System (INIS)

    Gosset, J.; Babinet, R.; Cavata, C.; Marco, M. de; Demoulins, M.; Fanet, H.; Fodor, Z.; L'Hote, D.; Lucas, B.

    1990-01-01

    A simple characterization of triple differential cross sections is needed for a systematic study of the nuclear matter collective flow in relativistic nucleus-nucleus collisions. Our analysis is based upon a fitting procedure, so that the triple differential distributions need not be measured in the whole momentum space. If the detector acceptance eliminates most spectator particles or if it is artificially restricted for doing so, this method leads to a flow characterization of the participant nuclear matter. The center-of-mass triple-differential momentum distributions are fitted to a simple analytical shape, namely an anisotropic Gaussian distribution. The adjusted parameters (flow angle and aspect ratios) are corrected for uncertainty in the event-by-event determination of the reaction plane azimuth (finite-number effects). Results are presented for neon-nucleus and argon-nucleus collisions at incident energy between 400 and 800 MeV per nucleon. Flow is already significant for light systems, and depends clearly upon the impact parameter

  13. Single-particle states vs. collective modes: friends or enemies ?

    Science.gov (United States)

    Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

    2018-05-01

    The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The collective mode arises as the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger spacings between relevant single particle states. Thus, the single-particle state and the collective mode are "enemies" against each other. However, the nuclear forces are rich enough so as to enhance relevant collective mode by reducing the resistance power by changing single-particle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, the quantum self-organization occurs: single-particle energies can be self-organized by (i) two quantum liquids, e.g., protons and neutrons, (ii) monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger.

  14. F2 phenomenological test on fuel motion (Interim report)

    International Nuclear Information System (INIS)

    Palm, R.G.; Fink, C.L.; Stewart, R.R.; Gehl, S.M.; Rothman, A.B.

    1976-09-01

    TREAT F-series tests are being conducted to provide data on fuel motion at accident power levels from one to about ten times design for use in development of fuel motion models. Test F2 was conducted to evaluate motion of high power fuel in a hypothetical LMFBR unprotected TUC (transient undercooling) accident. Fuel and fuel-boundary conditions following coolant boiling and dryout under TUC conditions are achieved in each F-series test with a single fuel element surrounded by a nuclear heated wall in a dry test capsule. Test F2 was conducted with a low burnup but restructured fuel element to investigate the effect of fuel vapor pressure on fuel motion. Results are presented and discussed

  15. Nuclear parton distributions

    Directory of Open Access Journals (Sweden)

    Kulagin S. A.

    2017-01-01

    Full Text Available We review a microscopic model of the nuclear parton distribution functions, which accounts for a number of nuclear effects including Fermi motion and nuclear binding, nuclear meson-exchange currents, off-shell corrections to bound nucleon distributions and nuclear shadowing. We also discuss applications of this model to a number of processes including lepton-nucleus deep inelastic scattering, proton-nucleus Drell-Yan lepton pair production at Fermilab, as well as W± and Z0 boson production in proton-lead collisions at the LHC.

  16. p-p minimum-bias dijets and nonjet quadrupole in relation to conjectured collectivity (flows in high-energy nuclear collisions

    Directory of Open Access Journals (Sweden)

    Trainor Thomas A.

    2016-01-01

    Full Text Available Recent observations of ridge-like structure in p-p and p-A angular correlations at the RHIC and LHC have been interpreted to imply collective motion in smaller collision systems. It is argued that if correlation structures accepted as manifestations of flow in A-A collisions appear in smaller systems collectivity (flow must extend to the smaller systems. But the argument could be reversed to conclude that such structures appearing in A-A collisions may not imply hydrodynamic flow. I present spectrum, correlation and fluctuation data from RHIC p-p and Au-Au collisions and p-p, p-Pb and Pb-Pb results from the LHC described accurately by a two-component (soft+dijet model of hadron production. I also present evidence for a significant p-p nonjet (NJ quadrupole (v2 component with nch systematics directly related to A-A NJ quadrupole systematics. The combination suggests that soft, dijet and NJ quadrupole com- ponents are distinct phenomena in all cases, inconsistent with hadron production from a common bulk medium exhibiting collective motion (flow.

  17. A guide to archival collections relating to radioactive fallout from nuclear weapon testing

    International Nuclear Information System (INIS)

    Martin, B.W.

    1992-09-01

    This ninth edition of A Guide to Archival Collections Relating to Radioactive Fallout from Nuclear Weapon Testing constitutes History Associates Incorporated's (HAI) final report of its document collection, processing, and declassification efforts for the Nevada Field Office of the Department of Energy. The most significant feature of this edition is the updated HAI collection effort information. We confirmed the accuracy of this information using our screening, processing, and transmittal records. Unlike previous editions, funding limitations prevented us from systematically revising the collection descriptions and point-of-contact information for this final edition. This guide has been prepared by professional historians who have a working knowledge of many of the record collections included in the following pages. In describing materials, they have tried to include enough information so that persons unfamiliar with the complexities of large record systems will be able to determine that nature of the information in, and the quality of, each record collection

  18. Motion Capture Technique Applied Research in Sports Technique Diagnosis

    Directory of Open Access Journals (Sweden)

    Zhiwu LIU

    2014-09-01

    Full Text Available The motion capture technology system definition is described in the paper, and its components are researched, the key parameters are obtained from motion technique, the quantitative analysis are made on technical movements, the method of motion capture technology is proposed in sport technical diagnosis. That motion capture step includes calibration system, to attached landmarks to the tester; to capture trajectory, and to analyze the collected data.

  19. Proceedings of the 34th International Workshop on Nuclear Theory (IWNT-34)

    International Nuclear Information System (INIS)

    Gaidarov, M.; Minkov, N.

    2015-01-01

    The 34th volume of the Nuclear Theory series contains articles based on the presentations given at the Thirty Fourth International Workshop on Nuclear Theory (IWNT-34) held from 21st to 27th of June 2015 in the Rila Mountains, Bulgaria. The main topics of the 2015 Workshop were: nuclear structure and reactions; symmetries and dynamics; collective and intrinsic motions of nuclei; exotic nuclei; few-body and many-fermion systems; nuclear astrophysics and related topics are part of the NTL’s program for basic nuclear physics research. This broad range of subjects gives a space for the participants to cover the most actual points of view relating the theory with experiment, providing interpretation and predictions, bridging interdisciplinary topics related to nuclear structure and reactions. The Workshop was attended by 25 participants (including the organizers) from 11 scientific institutions of 7 countries: Belgium, Bulgaria, Italy, France, Kazakhstan, Romania and Russia. The scientific program contained totally 16 oral talks and 3 posters

  20. Seismic Data for Evaluation of Ground Motion Hazards in Las Vegas in Support of Test Site Readiness Ground Motion

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A

    2008-01-16

    In this report we describe the data sets used to evaluate ground motion hazards in Las Vegas from nuclear tests at the Nevada Test Site. This analysis is presented in Rodgers et al. (2005, 2006) and includes 13 nuclear explosions recorded at the John Blume and Associates network, the Little Skull Mountain earthquake and a temporary deployment of broadband station in Las Vegas. The data are available in SAC format on CD-ROM as an appendix to this report.

  1. Collective and planetary motion in atoms

    International Nuclear Information System (INIS)

    Berry, R.S.

    1986-01-01

    The evolution of the conception of electron correlation is sketched, particularly the ideas that emerged in the late 1970s. Those ideas have led to a deep reexamination of the behavior of electrons sharing a valence shell. Doubly-excited helium was the first case in which it could be clearly established that the electronic states exhibit collective rotations and vibrations, rather than predominantly independent-particle-like behavior. More recently, it has appeared that the ground states and most but not all of the low-lying excited states of the alkaline-earth atoms are also much more like collective rotor-vibrators than like quantum analogues of solar systems. The appearance of such molecule-like characteristics for the electrons in atoms leads to a search for independent-particle-like behavior for atoms in highly excited vibrational states of small molecules such as H 2 O, NH 3 and CH 4 . Together, the two kinds of systems potentially exhibiting characteristics traditionally associated with the other suggest trying to find a more unified formulation of few-body problems that makes collective and independent-particle behavior into related but complementary manifestations of some more general characterization of the states of few-body systems. (Auth.)

  2. Signature scheme for the microscopic description of nuclear collective excitations

    International Nuclear Information System (INIS)

    Ogawa, K.

    1980-04-01

    The symmetries between the proton and neutron systems in a nucleus are described in terms of the signatures. Three kinds of signatures (i.e. the pn-, p anti n- and p anti p- (or n anti n-) signatures) are introduced and they are related to the appearance of various collective motions such as rotations or vibrations. It is shown that the pn-signature scheme provides a band-like structure of deformed nuclei, while the features associated with the quadrupole vibration are obtained in the p anti n- and p anti p-signature scheme. From the detail investigation of the p anti n-symmetric wave functions, it is concluded that the reguralities provided by the present shell model are more analogous to those of the γ-unstable surface vibration model (Wilets-Jean model) than to those of harmonic phonon model. (author)

  3. Anomalous nuclear enhancement of inclusive spectra at large transverse momentum

    International Nuclear Information System (INIS)

    Krzywicki, Andre.

    1976-01-01

    A parton model interpretation of the anomalous nuclear enhancement of inclusive spectra, observed by Cronin et al is proposed. It seems that the picture representing a nucleus as a collection of quasi-free nucleons in slow relative motion is incorrect when the nucleus is probed during a very short time. This conjecture rests on an extension to nuclei of the Kuti and Weisskopf parton model. A list of observable predictions concerning both hadronic and leptonic interactions with nuclei is given [fr

  4. Response analysis of a nuclear containment structure with nonlinear soil-structure interaction under bi-directional ground motion

    Science.gov (United States)

    Kumar, Santosh; Raychowdhury, Prishati; Gundlapalli, Prabhakar

    2015-06-01

    Design of critical facilities such as nuclear power plant requires an accurate and precise evaluation of seismic demands, as any failure of these facilities poses immense threat to the community. Design complexity of these structures reinforces the necessity of a robust 3D modeling and analysis of the structure and the soil-foundation interface. Moreover, it is important to consider the multiple components of ground motion during time history analysis for a realistic simulation. Present study is focused on investigating the seismic response of a nuclear containment structure considering nonlinear Winkler-based approach to model the soil-foundation interface using a distributed array of inelastic springs, dashpots and gap elements. It is observed from this study that the natural period of the structure increases about 10 %, whereas the force demands decreases up to 24 % by considering the soil-structure interaction. Further, it is observed that foundation deformations, such as rotation and sliding are affected by the embedment ratio, indicating an increase of up to 56 % in these responses for a reduction of embedment from 0.5 to 0.05× the width of the footing.

  5. Simulation of a marine nuclear reactor

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Kyouya, Masahiko; Kobayashi, Hideo; Ochiai, Masaaki

    1995-01-01

    A Nuclear-powered ship Engineering Simulation SYstem (NESSY) has been developed by the Japan Atomic Energy Research Institute as an advanced design tool for research and development of future marine reactors. A marine reactor must respond to changing loads and to the ship's motions because of the ship's maneuvering and its presence in a marine environment. The NESSY has combined programs for the reactor plant behavior calculations and the ship's motion calculations. Thus, it can simulate reactor power fluctuations caused by changing loads and the ship's motions. It can also simulate the behavior of water in the pressurizer and steam generators. This water sloshes in response to the ship's motions. The performance of NESSY has been verified by comparing the simulation calculations with the measured data obtained by experiments performed using the nuclear ship Mutsu. The effects of changing loads and the ship's motions on the reactor behavior can be accurately simulated by NESSY

  6. Anti-correlated spectral motion in bisphthalocyanines: evidence for vibrational modulation of electronic mixing.

    Science.gov (United States)

    Prall, Bradley S; Parkinson, Dilworth Y; Ishikawa, Naoto; Fleming, Graham R

    2005-12-08

    We exploit a coherently excited nuclear wave packet to study nuclear motion modulation of electronic structure in a metal bridged phthalocyanine dimer, lutetium bisphthalocyanine, which displays two visible absorption bands. We find that the nuclear coordinate influences the energies of the underlying exciton and charge resonance states as well as their interaction; the interplay of the various couplings creates unusual anti-correlated spectral motion in the two bands. Excited state relaxation dynamics are the same regardless of which transition is pumped, with decay time constants of 1.5 and 11 ps. The dynamics are analyzed using a three-state kinetic model after relaxation from one or two additional states faster than the experimental time resolution of 50-100 fs.

  7. Effect of respiratory motion on internal radiation dosimetry

    NARCIS (Netherlands)

    Xie, Tianwu; Zaidi, Habib

    2014-01-01

    Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences

  8. Changing perception about nuclear power in Slovenia in the changing political climate

    International Nuclear Information System (INIS)

    Stritar, Andrej; Istenff, Radko

    1998-01-01

    Public opinion about nuclear energy and in particular about the Nuclear Power Plant Krsko has experienced some fluctuations during last years. There were periods when attacks in media by the opponents were very heavy, which resulted also in a more negative public opinion about this kind of energy production. In the year 1995 and 1996 there was a very strong anti nuclear motion initiated by opponents. They wanted to organize a national referendum for the premature closure of the NPP Krsko. The motion was quite a big disaster, since they have managed to collect only about 6 of needed 40.000 signatures for the support of the referendum. After that there were very few open attacks against nuclear energy present in media. At the Nuclear Training Centre in Ljubljana we are continuing our long-term program of public education about nuclear energy. Elementary and High schools have a permanent invitation to visit us. We receive about 7000 students per year together with about 300 teachers. They all have opportunity to listen to the lecture about nuclear energy or about radioactive waste and to visit our permanent exhibition. In June 1997 we have repeated the pool among visitors, which was conducted already in years 1990, 91, 92, 93 and 1995. In the paper we will compare the results and try to draw some conclusions. Nuclear power is not the largest headline in Slovenia anymore. The influence of that can be seen also on public perception. Our poll of young people shows their better and more favorable perception of this way of energy production than in the past

  9. Experimental motion behavior of submerged fuel racks

    International Nuclear Information System (INIS)

    Ellingson, F.J.; Wachter, W.; Moscardini, R.L.

    1989-01-01

    The design of submerged nuclear storage racks for light water reactor nuclear fuel has undergone a change from fixed position to a free-standing arrangement. Seismic analysis of the motion of the free-standing racks requires three-dimensional computer modeling that uses past studies of hydrodynamic mass and hydraulic coupling for rigid flat plates. This paper describes the results of experiments that show a reduced value for hydrodynamic mass and coupling forces when flexible elements are involved. To support this work, experiments were run with two full-scale welded box sections submerged in a water tank. The preliminary results indicate reduction in hydrodynamic mass due to box wall flexibility, a lack of impacting of box wall to box wall over the entire frequency range, and large hydrodynamic coupling forces under all test conditions. It is hypothesized that the coupling forces are sufficiently strong to prevent rotational motion of one rack when surrounded by adjacent racks

  10. UMCE-FM: Untethered Motion Capture Evaluation for Flightline Maintenance Support

    National Research Council Canada - National Science Library

    Kider, Jr., Joseph T; Stocker, Catherine R; Badler, Norman I

    2008-01-01

    .... The primary objective was to determine the potential of untethered motion capture capabilities for real-time human subject motion capture and performance data collection with full-scale physical props...

  11. Reaction mechanisms in coherent nuclear photoproduction

    International Nuclear Information System (INIS)

    Lazard, C.

    Nuclear coherent pion photoproduction is studied. Pion rescattering and propagation effects inside nucleus and mesic exchange current effects are discussed. Influence of nuclear wave functions and Fermi motion is presented [fr

  12. A nuclear magnetic relaxation study on internal motion of polyelectrolytes in solution

    International Nuclear Information System (INIS)

    Schriever, J.

    1977-01-01

    The aim of this thesis is to investigate the significance and the amount of information which can be extracted from the study of frequency dependence of magnetic relaxation rates in solutions of a synthetic macromolecule. Solutions of poly(methacrylic acid), PMA, in water were chosen as the object of the present work. A short survey of nuclear magnetic relaxation in solutions of simple macromolecules is presented. Results obtained by continuous wave experiments on PMA solutions are shown (viz. the information about the transverse relaxation from line width analysis of 60 MHz proton spectra). Water enriched in 17 O is used in magnetic relaxation studies; the results of the determination of hydrogen lifetimes in aqueous solutions of acetic acid and poly(methacrylic acid) are given. The possibility of obtaining information about the dynamics of deuterons in the acid side groups of weak polyacids by measuring deuteron relaxation in heavy water solutions of those acids is considered. The use of deuteron relaxation rate experiments on solutions of selectively methylene deuterated poly(methacrylic acid), [-CD 2 -CCH 3 COOH-]n, is demonstrated and the backbone methylene C-atom motion is charachterized. The magne-tic relaxation of nuclei in the side groups of methylene deuterated PMA, viz. protons in the methyland deuterons in the acid side groups is presented

  13. Soil–structure interaction analyses to locate nuclear power plant free-field seismic instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, James J., E-mail: jasjjoh@aol.com [James J. Johnson and Associates, Alamo, CA (United States); Ake, Jon P. [US Nuclear Regulatory Commission, Washington, DC (United States); Maslenikov, Oleg R. [James J. Johnson and Associates, Alamo, CA (United States); Kenneally, Roger M. [Consultant, Seminole, FL (United States)

    2015-12-15

    Highlights: • Determine the location of seismic instrumentation so that recorded motion will be free-field motion. • Certified Designs of nuclear island for AP1000 and EPR; ABWR Reactor Building were analyzed. • Three site conditions and multiple recorded time histories were considered. • Instrumentation located 1-diameter from the edge of structure/foundation is adequate. • Acceptance criteria were probability of non-exceedance of response spectra values. - Abstract: The recorded earthquake ground motion at the nuclear power plant site is needed for several purposes. US Nuclear Regulatory Commission (NRC) Regulatory Guide 1.12, Nuclear Power Plant Instrumentation for Earthquakes, NRC (1997a), describes acceptable instrumentation to meet the requirements in NRC's regulations pertaining to earthquake engineering criteria for nuclear power plants. The ground motion data recorded by the free-field seismic instrumentation are used to compare the actual earthquake motion at the site with the design input motion. The result of the comparison determines if the Operating Basis Earthquake ground motion (OBE) has been exceeded and plant shutdown is required per the guidance in NRC Regulatory Guide 1.166, Pre-Earthquake Planning and Immediate Nuclear Power Plant Operator Postearthquake Actions, NRC (1979b). The free-field is defined as a location on the ground surface or in the site soil column that is sufficiently distant from the site structures to be essentially unaffected by the vibration of the site structures.

  14. Live Operation Data Collection Optimization and Communication for the Domestic Nuclear Detection Office's Rail Test Center

    International Nuclear Information System (INIS)

    Gelston, Gariann M.

    2010-01-01

    For the Domestic Nuclear Detection Office's Rail Test Center (i.e., DNDO's RTC), port operation knowledge with flexible collection tools and technique are essential in both technology testing design and implementation intended for live operational settings. Increased contextual data, flexibility in procedures, and rapid availability of information are keys to addressing the challenges of optimization, validation, and analysis within live operational setting data collection. These concepts need to be integrated into technology testing designs, data collection, validation, and analysis processes. A modified data collection technique with a two phased live operation test method is proposed.

  15. Frustration-guided motion planning reveals conformational transitions in proteins.

    Science.gov (United States)

    Budday, Dominik; Fonseca, Rasmus; Leyendecker, Sigrid; van den Bedem, Henry

    2017-10-01

    Proteins exist as conformational ensembles, exchanging between substates to perform their function. Advances in experimental techniques yield unprecedented access to structural snapshots of their conformational landscape. However, computationally modeling how proteins use collective motions to transition between substates is challenging owing to a rugged landscape and large energy barriers. Here, we present a new, robotics-inspired motion planning procedure called dCC-RRT that navigates the rugged landscape between substates by introducing dynamic, interatomic constraints to modulate frustration. The constraints balance non-native contacts and flexibility, and instantaneously redirect the motion towards sterically favorable conformations. On a test set of eight proteins determined in two conformations separated by, on average, 7.5 Å root mean square deviation (RMSD), our pathways reduced the Cα atom RMSD to the goal conformation by 78%, outperforming peer methods. We then applied dCC-RRT to examine how collective, small-scale motions of four side-chains in the active site of cyclophilin A propagate through the protein. dCC-RRT uncovered a spatially contiguous network of residues linked by steric interactions and collective motion connecting the active site to a recently proposed, non-canonical capsid binding site 25 Å away, rationalizing NMR and multi-temperature crystallography experiments. In all, dCC-RRT can reveal detailed, all-atom molecular mechanisms for small and large amplitude motions. Source code and binaries are freely available at https://github.com/ExcitedStates/KGS/. © 2017 Wiley Periodicals, Inc.

  16. Programs OPTMAN and SHEMMAN Version 6 (1999) - Coupled-Channels optical model and collective nuclear structure calculation -

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jong Hwa; Lee, Jeong Yeon; Lee, Young Ouk; Sukhovitski, Efrem Sh [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-01-01

    Programs SHEMMAN and OPTMAN (Version 6) have been developed for determinations of nuclear Hamiltonian parameters and for optical model calculations, respectively. The optical model calculations by OPTMAN with coupling schemes built on wave functions functions of non-axial soft-rotator are self-consistent, since the parameters of the nuclear Hamiltonian are determined by adjusting the energies of collective levels to experimental values with SHEMMAN prior to the optical model calculation. The programs have been installed at Nuclear Data Evaluation Laboratory of KAERI. This report is intended as a brief manual of these codes. 43 refs., 9 figs., 1 tabs. (Author)

  17. Nuclear resonant scattering of synchrotron radiation from nuclei in the Brownian motion

    International Nuclear Information System (INIS)

    Razdan, Ashok

    2003-01-01

    The time evolution of the coherent forward scattering of the synchrotron radiation for resonant nuclei in Brownian motion is studied. Apart from target thickness, the appearance of the dynamical beats also depends on 'α' which is the ratio of the harmonic force constant to the damping force constant of harmonic oscillator undergoing Brownian motion

  18. Self-consistent collective coordinate method for large amplitude collective motions

    International Nuclear Information System (INIS)

    Sakata, F.; Hashimoto, Y.; Marumori, T.; Une, T.

    1982-01-01

    A recent development of the self-consistent collective coordinate method is described. The self-consistent collective coordinate method was proposed on the basis of the fundamental principle called the invariance principle of the Schroedinger equation. If this is formulated within a framework of the time dependent Hartree Fock (TDHF) theory, a classical version of the theory is obtained. A quantum version of the theory is deduced by formulating it within a framework of the unitary transformation method with auxiliary bosons. In this report, the discussion is concentrated on a relation between the classical theory and the quantum theory, and an applicability of the classical theory. The aim of the classical theory is to extract a maximally decoupled collective subspace out of a huge dimensional 1p - 1h parameter space introduced by the TDHF theory. An intimate similarity between the classical theory and a full quantum boson expansion method (BEM) was clarified. Discussion was concentrated to a simple Lipkin model. Then a relation between the BEM and the unitary transformation method with auxiliary bosons was discussed. It became clear that the quantum version of the theory had a strong relation to the BEM, and that the BEM was nothing but a quantum analogue of the present classical theory. The present theory was compared with the full TDHF calculation by using a simple model. (Kato, T.)

  19. Nuclear ships and their safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1961-04-15

    Several aspects of nuclear ship propulsion, with special reference to nuclear safety, were discussed at an international symposium at Taormina, Italy, from 14-18 November 1960. Discussions on specific topics are conducted, grouped under the following headings: Economics and National Activities in Nuclear Ship Propulsion; International Problems and General Aspects of Safety for Nuclear Ships; Nuclear Ship Projects from the Angle of Safety; Ship Reactor Problems; Sea Motion and Hull Problems; Maintenance and Refuelling Problems; and Safety Aspects of Nuclear Ship Operation.

  20. Two-pulse laser control of nuclear and electronic motion

    DEFF Research Database (Denmark)

    Grønager, Michael; Henriksen, Niels Engholm

    1997-01-01

    We discuss an explicitly time-dependent two-pulse laser scheme for controlling where nuclei and electrons are going in unimolecular reactions. We focus on electronic motion and show, with HD+ as an example, that one can find non-stationary states where the electron (with some probability...

  1. Single-particle motion in large-amplitude quadrupole shape transition

    International Nuclear Information System (INIS)

    Yamada, Kazuya

    1991-01-01

    The microscopic structure of the single-particle motion for the spherical-deformed transitional nuclei is analysed by using the self-consistent collective-coordinate method (SCC method). The single-particle motion in the moving-frame of reference called the collective vibrating coordinate frame is introduced by the generalized Bogoliubov transformation depending on the collective coordinate. The numerical calculations of the single-particle (quasi-particle) energy level diagrams and their occupation probabilities for the static deformation are carried out for the Sm isotopes. A clear change of the single-particle distribution structure appears in the course of deformation. (author)

  2. Prediction of strong earthquake motions on rock surface using evolutionary process models

    International Nuclear Information System (INIS)

    Kameda, H.; Sugito, M.

    1984-01-01

    Stochastic process models are developed for prediction of strong earthquake motions for engineering design purposes. Earthquake motions with nonstationary frequency content are modeled by using the concept of evolutionary processes. Discussion is focused on the earthquake motions on bed rocks which are important for construction of nuclear power plants in seismic regions. On this basis, two earthquake motion prediction models are developed, one (EMP-IB Model) for prediction with given magnitude and epicentral distance, and the other (EMP-IIB Model) to account for the successive fault ruptures and the site location relative to the fault of great earthquakes. (Author) [pt

  3. The Dynamics of Large-Amplitude Motion in Energized Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Perry, David S. [Univ. of Akron, OH (United States). Dept. of Chemistry

    2016-05-27

    Chemical reactions involve large-amplitude nuclear motion along the reaction coordinate that serves to distinguish reactants from products. Some reactions, such as roaming reactions and reactions proceeding through a loose transition state, involve more than one large-amplitude degree of freedom. Because of the limitation of exact quantum nuclear dynamics to small systems, one must, in general, define the active degrees of freedom and separate them in some way from the other degrees of freedom. In this project, we use large-amplitude motion in bound model systems to investigate the coupling of large-amplitude degrees of freedom to other nuclear degrees of freedom. This approach allows us to use the precision and power of high-resolution molecular spectroscopy to probe the specific coupling mechanisms involved, and to apply the associated theoretical tools. In addition to slit-jet spectra at the University of Akron, the current project period has involved collaboration with Michel Herman and Nathalie Vaeck of the Université Libre de Bruxelles, and with Brant Billinghurst at the Canadian Light Source (CLS).

  4. Characterization of design ground motion for the central and eastern United States: licensing implications

    International Nuclear Information System (INIS)

    Litehiser, J.; Carrato, P.

    2005-01-01

    For the first time in decades several US utilities are exploring the possibility of building new Nuclear Power Plant (NPP) generating capacity in the Central and Eastern United States (CEUS). Among the many topics that must be considered to license a nuclear plant (NPP) is appropriate design to mitigate the potential effects of vibratory ground motion from earthquakes. Agreement on seismic design ground motion was not always easy during licensing of the last generation of NPPs. Therefore, over the last few decades both industry and the United States Nuclear Regulatory Commission (USNRC) have worked to find ground motion criteria that recognize and overcome earlier licensing difficulties. Such criteria should be stable and easily implemented. Important and complementary programs under the direction of the Lawrence Livermore National Laboratory (LLNL) and the Electric Power Research Institute (EPRI) were part of this effort, and these studies resulted in probabilistic seismic hazard assessments (PSHAs) for a number of CEUS NPP sites. These results and the concepts underlying them are now incorporated into both USNRC regulation and regulatory guidance. Nevertheless, as the utilities and the NRC begin a renewed licensing dialog, issues of regulatory interpretation of earthquake ground motion design criteria have emerged. These issues are as fundamental as the shape and amplitude of ground motion design response spectra and as significant as the impact of these spectra on structural design. Successful and timely resolution of these issues will significantly impact the future of nuclear power in the US. The purpose of this paper is to briefly describe some of these issues and the approaches that have been proposed for their resolution. (authors)

  5. Advanced methods on the evaluation of design earthquake motions for important power constructions

    International Nuclear Information System (INIS)

    Higashi, Sadanori; Shiba, Yoshiaki; Sato, Hiroaki; Sato, Yusuke; Nakajima, Masato; Sakai, Michiya; Sato, Kiyotaka

    2009-01-01

    In this report, we compiled advanced methods on the evaluation of design earthquake motions for important power constructions such as nuclear power, thermal power, and hydroelectric power facilities. For the nuclear and hydroelectric power facilities, we developed an inversion method of broad-band (0.1-5Hz) source process and obtained valid results from applying the method to the 2007 Niigata-ken Chuetsu-oki earthquake (M6.8). We have also improved our modeling techniques of thick sedimentary layered structure such as the S-wave velocity modeling by using microtremor array measurement and the frequency dependent damping factor with a lower limit. For seismic isolation design for nuclear power facilities, we proposed a design pseudo-velocity response spectrum. For the thermal power facilities, we performed three-dimensional numerical simulation of Kanto Basin for a prediction relation of long-period ground motion. We also proposed the introduction of probabilistic approach into the deterministic evaluation flow of design earthquake motions and evaluated the effect of a great earthquake with a short return period on the seismic hazard in Miyagi Prefecture, Japan. (author)

  6. Ground motion characteristics of 2007 Niigata-ken Chuetsu-oki earthquake

    International Nuclear Information System (INIS)

    Hijikata, Katsuichirou; Nishimura, Isao; Mizutani, Hiroyuki; Tokumitsu, Ryoichi; Mashimo, Mitsugu; Tanaka, Shinya

    2010-01-01

    Strong motion records of 2007 Niigata-ken Chuetsu-oki earthquake were examined in order to evaluate ground motion characteristics of the earthquake. Ground motions observed at Kashiwazaki Kariwa Nuclear Power Plant site were significantly larger than the response spectra evaluated on the basis of Noda et al. (2002), and the level of the ground motion observed at Arahama area (unit 1-4 side) was approximately twice as large as that at Ominato area (unit 5-7 side). Observation records of the offshore events other than the earthquake were also larger than the response spectra based on Noda et al. (2002), whereas records of the inland events were smaller than those. In addition, these characteristics were also observed in the vicinity of the site through the analysis of the ground motion records obtained by KiK-net. (author)

  7. Surface motion near underground nuclear explosions in desert alluvium Operation Nougat I, Area 3, Nevada Test Site

    International Nuclear Information System (INIS)

    Perret, W.R.

    1978-05-01

    During Operation Nougat I, which was conducted in late 1961 and the first half of 1962, Sandia Laboratories measured surface motion in the vicinity of all contained underground nuclear explosions conducted by the Los Alamos Scientific Laboratory in Area 3 of the Nevada Test Site. This report presents and analyses most of the data derived from that study. Propagation velocities in the desert alluvium, 4440 ft/sec, and underlying tuff, 6020 ft/sec, are typical of those derived from later measurements. Motion attenuation data exhibit considerable scatter, in part because of early measurement and data reduction techniques but primarily because of differences in the characteristics of the geologic media which had not then been recognized. However, regression fits to the scaled data show attenuation of scaled acceleration at a rate 35% greater than that observed for Merlin event data (Merlin was conducted later in Area 3). The attenuation rate for particle velocity data from Nougat I events was 47% less than that for Merlin data, and the Nougat I scaled displacement data attenuation rate was 87% less than that for Merlin data. Analysis of data from a vertical string of gages extending to the surface above the Mink explosion has established a significant difference between normal spallation above contained explosions in competent rock and the reaction of uncemented alluvium to similar explosive loading

  8. Measurement and Quantification of Gross Human Shoulder Motion

    Directory of Open Access Journals (Sweden)

    Jeremy T. Newkirk

    2013-01-01

    Full Text Available The shoulder girdle plays an important role in the large pointing workspace that humans enjoy. The goal of this work was to characterize the human shoulder girdle motion in relation to the arm. The overall motion of the human shoulder girdle was characterized based on motion studies completed on test subjects during voluntary (natural/unforced motion. The collected data from the experiments were used to develop surface fit equations that represent the position and orientation of the glenohumeral joint for a given humeral pointing direction. These equations completely quantify gross human shoulder girdle motion relative to the humerus. The equations are presented along with goodness-of-fit results that indicate the equations well approximate the motion of the human glenohumeral joint. This is the first time the motion has been quantified for the entire workspace, and the equations provide a reference against which to compare future work.

  9. 78 FR 28244 - Agency Information Collection Activities; Proposed Collection; Comment Request

    Science.gov (United States)

    2013-05-14

    ... Licensing of Production and Utilization Facilities,'' specifies technical information and data to be... NUCLEAR REGULATORY COMMISSION [Docket No. NRC-2013-0085] Agency Information Collection Activities; Proposed Collection; Comment Request AGENCY: Nuclear Regulatory Commission. ACTION: Notice of pending NRC...

  10. Motion correction options in PET/MRI.

    Science.gov (United States)

    Catana, Ciprian

    2015-05-01

    Subject motion is unavoidable in clinical and research imaging studies. Breathing is the most important source of motion in whole-body PET and MRI studies, affecting not only thoracic organs but also those in the upper and even lower abdomen. The motion related to the pumping action of the heart is obviously relevant in high-resolution cardiac studies. These two sources of motion are periodic and predictable, at least to a first approximation, which means certain techniques can be used to control the motion (eg, by acquiring the data when the organ of interest is relatively at rest). Additionally, nonperiodic and unpredictable motion can also occur during the scan. One obvious limitation of methods relying on external devices (eg, respiratory bellows or the electrocardiogram signal to monitor the respiratory or cardiac cycle, respectively) to trigger or gate the data acquisition is that the complex motion of internal organs cannot be fully characterized. However, detailed information can be obtained using either the PET or MRI data (or both) allowing the more complete characterization of the motion field so that a motion model can be built. Such a model and the information derived from simple external devices can be used to minimize the effects of motion on the collected data. In the ideal case, all the events recorded during the PET scan would be used to generate a motion-free or corrected PET image. The detailed motion field can be used for this purpose by applying it to the PET data before, during, or after the image reconstruction. Integrating all these methods for motion control, characterization, and correction into a workflow that can be used for routine clinical studies is challenging but could potentially be extremely valuable given the improvement in image quality and reduction of motion-related image artifacts. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Semi-automatic detection and correction of body organ motion, particularly cardiac motion in SPECT studies

    International Nuclear Information System (INIS)

    Quintana, J.C.; Caceres, F.; Vargas, P.

    2002-01-01

    patient and artificially imposed). The method is fast (<20s) and robust as compared with manual or other semi-automatic detection of body organ motions in nuclear medicine studies. Conclusion: A fast and robust semi-automatic patient motion detection and correction for SPECT studies has been developed

  12. Data-driven motion correction in brain SPECT

    International Nuclear Information System (INIS)

    Kyme, A.Z.; Hutton, B.F.; Hatton, R.L.; Skerrett, D.W.

    2002-01-01

    Patient motion can cause image artifacts in SPECT despite restraining measures. Data-driven detection and correction of motion can be achieved by comparison of acquired data with the forward-projections. By optimising the orientation of the reconstruction, parameters can be obtained for each misaligned projection and applied to update this volume using a 3D reconstruction algorithm. Digital and physical phantom validation was performed to investigate this approach. Noisy projection data simulating at least one fully 3D patient head movement during acquisition were constructed by projecting the digital Huffman brain phantom at various orientations. Motion correction was applied to the reconstructed studies. The importance of including attenuation effects in the estimation of motion and the need for implementing an iterated correction were assessed in the process. Correction success was assessed visually for artifact reduction, and quantitatively using a mean square difference (MSD) measure. Physical Huffman phantom studies with deliberate movements introduced during the acquisition were also acquired and motion corrected. Effective artifact reduction in the simulated corrupt studies was achieved by motion correction. Typically the MSD ratio between the corrected and reference studies compared to the corrupted and reference studies was > 2. Motion correction could be achieved without inclusion of attenuation effects in the motion estimation stage, providing simpler implementation and greater efficiency. Moreover the additional improvement with multiple iterations of the approach was small. Improvement was also observed in the physical phantom data, though the technique appeared limited here by an object symmetry. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  13. On the Motion of Falling Leaves

    OpenAIRE

    Razavi, Pedram

    2010-01-01

    This paper investigates the motion of falling leaves through modeling using papers and the corresponding data collected from more than four thousands experiments. Two series of experiments were designed in order to study the relationship between different parameters which can affect different paths of motion in leaves. In the first series of experiments, the shapes of the potential paths that falling papers can take were investigated as a whole. A new classification scheme was derived from th...

  14. Collective motion and multifragmentation in the central collisions of the Xe+Sn System at 50 MeV/nucleon

    International Nuclear Information System (INIS)

    Marie, Nathalie

    1995-01-01

    This work concerns the search of an experimental signature of a collective motion in the process of the multifragmentation of hot nuclei formed in the central collisions of the Xe+Sn System at 50 MeV/nucleon. The measurements have been performed with the multidetector INDRA. The central collisions have been selected by means of a shape variable using momenta of the fragments. The spectra and the charge distributions of the products show that most of the charged particles and fragments comes from the disintegration of an equilibrated source. A minimum value of 40 mb is given for the cross section of such a mechanism. The charge (79) and the excitation energy (12.5 MeV/nucleon) of the equilibrated source have been determined by counting and with the calorimetry method. Comparison to the predictions of a sequential binary model and a phenomenological simultaneous model have been made. Only the simultaneous disintegration is able to explain the distribution of the relative angle between fragments. The energy spectra of the fragment are correctly reproduced assuming a collective energy of 2 MeV/nucleon. No dependence of this collective energy is found respect to the charge of the fragment. However, this process of a multifragmentation with a collective energy fails to explain the properties of the light charged particles. (author) [fr

  15. Interplay between one-body and collisional damping of collective motion in nuclei

    International Nuclear Information System (INIS)

    Kolomietz, V.M.; Plujko, V.A.; Shlomo, S.

    1996-01-01

    Damping of giant collective vibrations in nuclei is studied within the framework of the Landau-Vlasov kinetic equation. A phenomenological method of independent sources of dissipation is proposed for taking into account the contributions of one-body dissipation, the relaxation due to the two-body collisions and the particle emission. An expression for the intrinsic width of slow damped collective vibrations is obtained. In the general case, this expression cannot be represented as a sum of the widths associated with the different independent sources of the damping. This is a peculiarity of the collisional Landau-Vlasov equation where the Fermi-surface distortion effect influences both the self-consistent mean field and the memory effect at the relaxation processes. The interplay between the one-body, the two-body, and the particle emission channels which contribute to the formation of the total intrinsic width of the isoscalar 2 + and 3 - and isovector 1 - giant multipole resonances in cold and hot nuclei is discussed. We have shown that the criterion for the transition temperature T tr between the zero-sound and first-sound regimes in hot nuclei is different from the case of infinite nuclear matter due to the contribution from the one-body relaxation and the particle emission. In the case of the isovector GDR the corresponding transition can be reached at temperature T tr =4 endash 5 MeV. copyright 1996 The American Physical Society

  16. Collective motion in animal groups from a neurobiological perspective: the adaptive benefits of dynamic sensory loads and selective attention.

    Science.gov (United States)

    Lemasson, B H; Anderson, J J; Goodwin, R A

    2009-12-21

    We explore mechanisms associated with collective animal motion by drawing on the neurobiological bases of sensory information processing and decision-making. The model uses simplified retinal processes to translate neighbor movement patterns into information through spatial signal integration and threshold responses. The structure provides a mechanism by which individuals can vary their sets of influential neighbors, a measure of an individual's sensory load. Sensory loads are correlated with group order and density, and we discuss their adaptive values in an ecological context. The model also provides a mechanism by which group members can identify, and rapidly respond to, novel visual stimuli.

  17. Free-field ground motions for the nonproliferation experiment: Preliminary comparisons with nearby nuclear events

    International Nuclear Information System (INIS)

    Olsen, K.H.; Peratt, A.L.

    1994-01-01

    Since 1987, we have installed fixed arrays of tri-axial accelerometers in the fire-field near the shot horizons for low-yield (≤ 20 kt) nuclear events in the N-tunnel complex beneath Rainier Mesa. For the Nonproliferation Experiment (NPE) we augmented the array to achieve 23 free-field stations. Goals are: (a) to examine robustness and stability of various free-field source function estimates -- e.g., reduced displacement potentials (RDP) and spectra; (b) to compare close-in with regional estimates to test whether detailed close-in free-field and/or surface ground motion data can improve predictability of regional-teleseismic source functions; (c) to provide experimental data for checking two-dimensional numerical simulations. We report preliminary comparisons between experimental free-field data for NPE (1993) and three nearby nuclear events (MISTY ECHO, 1988; MINERAL QUARRY, 1990; HUNTERS TROPHY, 1992). All four working points are within 1 km of each other in the same wet tuff bed, thus reducing concerns about possible large differences in material properties between widely separated shots. Initial comparison of acceleration and velocity seismograms for the four events reveals: (1) There is a large departure from the spherical symmetry commonly assumed in analytic treatments of source theory; both vertical and tangential components are surprisingly large. (2) All shots show similar first-peak particle-velocity amplitude decay rates suggesting significant attenuation even in the supposedly purely elastic region. (3) Sharp (>20 Hz) arrivals are not observed at tunnel level from near-surface pP reflections or spall-closure sources -- but broadened peaks are seen that suggest more diffuse reflected energy from the surface and from the Paleozoic limestone basement below tunnel level

  18. Imaging of left ventricular wall motion via venous DSA

    International Nuclear Information System (INIS)

    Witte, G.; Roediger, W.; Buecheler, E.; Hamburg Univ.

    1986-01-01

    Until now, angiographical and nuclear medicine examination techniques for imaging left ventricular wall motion have been presenting with difficulties endemic to the methods themselves. For the first time in cardiological diagnostics, digital subtraction angiography (DSA) makes it possible to perform a fairly non-invasive examination with good spatial and temporal resolution. Functional analytic evaluation, however, still demands time-consuming, complicated post-processing. In this article we introduce a method that uses an additive window technique for the immediate generation of wall motion images. (orig.) [de

  19. Far from the intermediate nuclear field

    International Nuclear Information System (INIS)

    Dietrich, K.; Wagner, G.J.; Gregoire, C.; Campi, X.; Silvestre-Brac, B.; Platchkov, S.; Mayer, B.; Abgrall, Y.; Bohigas, O.; Grange, P.; Signarbieux, C.

    1988-01-01

    Pairing correlations in nuclear physics; the BCS state and quasi-particles; the layer model; collision effects on nuclear dynamics; the theory of cluster formation (application to nucleus fragmentation); short range correlations (few-particle systems); deuterium electron scattering; dibaryonic resonances; traditional and exotic hadron probes of nuclear structure; spectral fluctuations and chaotic motion; corrections to the intermediate nuclear field (nonrelativistic and other effects); and heavy nuclei splitting and nuclear superfluidity are introduced [fr

  20. Guide to the collection and presentation of electrical, electronic, and sensing component reliability data for nuclear-power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This Guide is intended to establish a method of collecting and presenting reliability data for quantitative systematic reliability analysis in nuclear power generating stations, as outlined in IEEE Std 351-1975. Appendix D, which is not a part of IEEE Std 500-1977 but which comprises the bulk of this publication, presents tables of reliability data for nuclear power generating stations, intended for use of nuclear systems reliability analysts or design engineers

  1. 75 FR 9444 - Agency Information Collection Activities: Proposed Collection; Comment Request

    Science.gov (United States)

    2010-03-02

    ... Utilization Facilities,'' specifies technical information and data to be provided to the NRC or maintained by... NUCLEAR REGULATORY COMMISSION [Docket No. NRC-2010-0063] Agency Information Collection Activities: Proposed Collection; Comment Request AGENCY: U.S. Nuclear Regulatory Commission (NRC). ACTION: Notice of...

  2. Using Co-located Rotational and Translational Ground-Motion Sensors to Characterize Seismic Scattering in the P-Wave Coda

    Science.gov (United States)

    Bartrand, J.; Abbott, R. E.

    2017-12-01

    We present data and analysis of a seismic data collect at the site of a historical underground nuclear explosion at Yucca Flat, a sedimentary basin on the Nevada National Security Site, USA. The data presented here consist of active-source, six degree-of-freedom seismic signals. The translational signals were collected with a Nanometrics Trillium Compact Posthole seismometer and the rotational signals were collected with an ATA Proto-SMHD, a prototype rotational ground motion sensor. The source for the experiment was the Seismic Hammer (a 13,000 kg weight-drop), deployed on two-kilometer, orthogonal arms centered on the site of the nuclear explosion. By leveraging the fact that compressional waves have no rotational component, we generated a map of subsurface scattering and compared the results to known subsurface features. To determine scattering intensity, signals were cut to include only the P-wave and its coda. The ratio of the time-domain signal magnitudes of angular velocity and translational acceleration were sectioned into three time windows within the coda and averaged within each window. Preliminary results indicate an increased rotation/translation ratio in the vicinity of the explosion-generated chimney, suggesting mode conversion of P-wave energy to S-wave energy at that location. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  3. Path-integral in collective variables and its application to nuclear and hadron physics

    International Nuclear Information System (INIS)

    Pervushin, V.N.; Rajnkhardt, Kh.; Ehbert, D.

    1979-01-01

    The application of functional integrals to describe collective degrees of freedom in different fields of physics is reviewed for the period since 1965. The application of path integrals to the schematic model of nuclear multiparticle systems with pairing and particle-hole forces permits to lay strict foundations under the so called theory of nuclear field, which hitherto was proved euristically. The Abel gauge theory of interacting massless quarks and vector gluons is described. In this model radiative corrections cause spontaneous dynamic breaking of the chiral γ 5 -invariance. The application of functional integration to two-dimensional quantum chromodynamics is also analyzed. It is shown that the local quark-gluon theory can be transformed in an infinite-component nonpolynomial field theory in terms of colourless bound states - mesons. A modified perturbation theory appears in the form of 1/Nsub(c)-expansion (Nsub(c) - number of quarks), that is formally is very akin to the 1/Ω-expansion (Ωdegeneracy of single-particle states) in the theory of nuclear field

  4. Study on scaling law of PWR natural circulation with motion condition

    International Nuclear Information System (INIS)

    Lu Donghua; Xiao Zejun; Chen Bingde

    2009-01-01

    For some nuclear reactors installed on automobiles, boats or deep sea vehicles, it is an important way to investigate their system safety by performing natural circulation experiments under motion condition. This paper studied the natural circulation on moving plants based on work of static natural circulation scaling method. With rigid motion theory, acceleration at each point was obtained on primary system and introduced to momentum equation. Thus a set of motion similar criteria were obtained. Furthermore, equal and unequal height simulation were analyzed. As to the unequal one, non isochronous simulation was needed for displacement and angular acceleration. (authors)

  5. Extreme ground motions and Yucca Mountain

    Science.gov (United States)

    Hanks, Thomas C.; Abrahamson, Norman A.; Baker, Jack W.; Boore, David M.; Board, Mark; Brune, James N.; Cornell, C. Allin; Whitney, John W.

    2013-01-01

    Yucca Mountain is the designated site of the underground repository for the United States' high-level radioactive waste (HLW), consisting of commercial and military spent nuclear fuel, HLW derived from reprocessing of uranium and plutonium, surplus plutonium, and other nuclear-weapons materials. Yucca Mountain straddles the western boundary of the Nevada Test Site, where the United States has tested nuclear devices since the 1950s, and is situated in an arid, remote, and thinly populated region of Nevada, ~100 miles northwest of Las Vegas. Yucca Mountain was originally considered as a potential underground repository of HLW because of its thick units of unsaturated rocks, with the repository horizon being not only ~300 m above the water table but also ~300 m below the Yucca Mountain crest. The fundamental rationale for a geologic (underground) repository for HLW is to securely isolate these materials from the environment and its inhabitants to the greatest extent possible and for very long periods of time. Given the present climate conditions and what is known about the current hydrologic system and conditions around and in the mountain itself, one would anticipate that the rates of infiltration, corrosion, and transport would be very low—except for the possibility that repository integrity might be compromised by low-probability disruptive events, which include earthquakes, strong ground motion, and (or) a repository-piercing volcanic intrusion/eruption. Extreme ground motions (ExGM), as we use the phrase in this report, refer to the extremely large amplitudes of earthquake ground motion that arise at extremely low probabilities of exceedance (hazard). They first came to our attention when the 1998 probabilistic seismic hazard analysis for Yucca Mountain was extended to a hazard level of 10-8/yr (a 10-4/yr probability for a 104-year repository “lifetime”). The primary purpose of this report is to summarize the principal results of the ExGM research program

  6. Analysis of the evolution of the collective dose in nuclear power plants in Spain; Analisis de la evolucion de la dosis colectiva en las centrales nucleares de Espana

    Energy Technology Data Exchange (ETDEWEB)

    Ponjuan Reyes, G.; Ruibia Rodiz, M. A. de la; Rosales Calvo, M.; Labarta Mancho, T.; Calavia Gimenez, I.

    2011-07-01

    This article presents an analysis of the evolution of occupational collective dose of the Spanish nuclear power plants during the period 2000 - 2008 within the international context, by the Nuclear Safety Council (CSN) in order to have information contrasted to assessing the extent of application of the ALARA criteria in the Spanish plants and identify areas of priority attention.

  7. Auditory motion capturing ambiguous visual motion

    Directory of Open Access Journals (Sweden)

    Arjen eAlink

    2012-01-01

    Full Text Available In this study, it is demonstrated that moving sounds have an effect on the direction in which one sees visual stimuli move. During the main experiment sounds were presented consecutively at four speaker locations inducing left- or rightwards auditory apparent motion. On the path of auditory apparent motion, visual apparent motion stimuli were presented with a high degree of directional ambiguity. The main outcome of this experiment is that our participants perceived visual apparent motion stimuli that were ambiguous (equally likely to be perceived as moving left- or rightwards more often as moving in the same direction than in the opposite direction of auditory apparent motion. During the control experiment we replicated this finding and found no effect of sound motion direction on eye movements. This indicates that auditory motion can capture our visual motion percept when visual motion direction is insufficiently determinate without affecting eye movements.

  8. Proceedings of the 30th International Workshop on Nuclear Theory (IWNT-30)

    International Nuclear Information System (INIS)

    Georgieva, A. I.; Minkov, N.

    2011-01-01

    The Thirtieth Anniversary International Workshop on Nuclear Theory was held between 27 June and 2 July 2011 in Rila Mountains, Bulgaria. The main topics of the program were: nucleon-nucleon correlation effects on nuclear structure and reactions; symmetries in nuclear structure; collective and intrinsic motions of nuclei; exotic nuclei; few-body systems; advanced studies of many-fermion systems; nuclear astrophysics and related topics. They are related to the problems contained in the research plan of the Nuclear Theory Laboratory of the Institute for Nuclear Research and Nuclear Energy of the Bulgarian Academy of Sciences. The Workshop was attended by 49 participants (including the organizers) from France, Germany, Greece, Italy, Japan, Kazakhstan, Romania, Russia, South Africa, Spain, USA and Bulgaria. The scientific program contained totally 32 oral talks. The schedule of the Workshop was organized so as to provide an opportunity for meetings and discussions among scientists with common interests as well as among physicists working in different fields of research. The secluded mountain area and the lovely forest venue allowed the participants to concentrate on their scientific work but also to refresh between the sessions and get an inspiration for future work development

  9. Data collection and record keeping for the management of nuclear power plant ageing: A safety practice

    International Nuclear Information System (INIS)

    1991-01-01

    This Safety Practice is the first in a series of reports under the programme on the management of nuclear power plant ageing. The purpose of the programme is to facilitate the exchange of information and to promote co-operation among Member States towards understanding and managing the ageing degradation of components, with the aim of maintaining safe and reliable plant operation. The availability and evaluation of appropriate data on nuclear power plant components are essential to safety and constitute a key factor in plant life extension considerations. The present publication provides guidance on data requirements and an effective and practical system for data collection and record keeping in relation to the evaluation and management of ageing and service life. This guidance is based on current practices. It is envisaged that the application of the guidance will contribute to the safe and reliable operation of nuclear power plants and will facilitate international information exchange on ageing related component failures, malfunctions and degradation, since data collected using the same ground rules would be easier to exchange and compare. The guidance is intended primarily for the management, maintenance and technical staff of nuclear power plants, on whom the ultimate success of the recommended system and its associated benefits depend. Intended secondary audiences include utility management and central technical support organizations, regulatory bodies, standards organizations, design companies, and research and development institutes. 8 refs, 1 fig., 1 tab

  10. Application of inertial sensors for motion analysis

    Directory of Open Access Journals (Sweden)

    Ferenc Soha

    2012-06-01

    Full Text Available This paper presents our results on the application of various inertial sensors for motion analysis. After the introduction of different sensor types (accelerometer, gyroscope, magnetic field sensor, we discuss the possible data collection and transfer techniques using embedded signal processing and wireless data communication methods [1,2]. Special consideration is given to the interpretation of accelerometer readings, which contains both the static and dynamic components, and is affected by the orientation and rotation of the sensor. We will demonstrate the possibility to decompose these components for quasiperiodic motions. Finally we will demonstrate the application of commercially available devices (Wii sensor, Kinect sensor, mobile phone for motion analysis applications.

  11. Liquid metal cooled nuclear reactor

    International Nuclear Information System (INIS)

    Leigh, K.M.

    1980-01-01

    A liquid metal cooled nuclear reactor is described, wherein coolant is arranged to be flowed upwardly through a fuel assembly and having one or more baffles located above the coolant exit of the fuel assembly, the baffles being arranged so as to convert the upwardly directed motion of liquid metal coolant leaving the fuel assembly into a substantially horizontal motion. (author)

  12. Nuclear collectivity and complex alignment mechanisms in light tungsten and osmium nuclei

    International Nuclear Information System (INIS)

    Johnson, N.R.

    1989-01-01

    During the past few years there have been significant advances in our understanding of nuclei excited into states of high angular momentum. The development of large multi-detector arrays for γ-γ coincidence spectroscopy studies has propelled the amount of new experimental information available and this has been complemented by notable advances in the theoretical treatments of high-spin phenomena. To provide yet a more detailed understanding of the structure of these high-spin states and to provide a stringent test of these models, we have resorted to measurements of their dynamic electromagnetic multipole moments which are a direct reflection of the collective aspects of the nuclear wave functions. For the most part, these multipole moments are obtained by lifetime measurements utilizing Doppler-shift techniques. Let me stress that the great value of lifetime measurements is that they provide the transition matrix elements without the necessity to rely on nuclear models. 24 refs., 10 figs

  13. Using smartphone as a motion detector to collect time-microenvironment data for estimating the inhalation dose

    International Nuclear Information System (INIS)

    Hoi, Tran Xuan; Phuong, Huynh Truc; Van Hung, Nguyen

    2016-01-01

    During the production of iodine-131 from neutron irradiated tellurium dioxide by the dry distillation, a considerable amount of "1"3"1I vapor is dispersed to the indoor air. People who routinely work at the production area may result in a significant risk of exposure to chronic intake by inhaled "1"3"1I. This study aims to estimate the inhalation dose for individuals manipulating the "1"3"1I at a radioisotope production. By using an application installed on smartphones, we collected the time-microenvironment data spent by a radiation group during work days in 2015. Simultaneously, we used a portable air sampler combined with radioiodine cartridges for grabbing the indoor air samples and then the daily averaged "1"3"1I concentration was calculated. Finally, the time-microenvironment data jointed with the concentration to estimate the inhalation dose for the workers. The result showed that most of the workers had the annual internal dose in 1÷6 mSv. We concluded that using smartphone as a motion detector is a possible and reliable way instead of the questionnaires, diary or GPS-based method. It is, however, only suitable for monitoring on fixed indoor environments and limited the targeted people. - Highlights: • We constructed the time-microenvironment patterns with 1-min resolution by using a smartphone application. • Exposure to "1"3"1I at the dry distillation areas may lead to an acute inhalation dose significantly. • Using smartphone as a motion detector in indoor exposure monitoring is a reliable method.

  14. Nuclear structure at high and very high spin theoretical description

    International Nuclear Information System (INIS)

    Szymanski, Z.

    1983-11-01

    When the existence of nuclear shell structure is ignored and nuclear motion is assumed to be classical we may expect that the nuclear rotation resembles that of a liquid drop. Energy of the nucleus can be thus considered as a sum of three terms: surface energy, Coulomb energy and rotational energy. Nuclear moment of inertia is assumed to be that of a rigid-body. The results of a calculation of the energy surfaces in rotating nuclei by Cohen, Plasil and Swiatecki are discussed. Cranking procedure is analysed as a tool to investigate nucleonic orbits in a rotating nuclear potential. Some predictions concerning the possible onset of a superdeformed phase are given. The structure of nuclear rotation is examined in the presence of the short-range pairing forces that generate the superfluid correlations in the nucleus. Examples of the Bengtsson-Frauendorf plots (quasiparticle energies versus angular velocity of rotation) are given and discussed. The backbending phenomenon is analysed in terms of band crossing. The dependence of the crossing frequency on the pairing-force strength is discussed. Possibilities of the role of new components in the two-body force (quadrupole-pairing) are considered. Possibilities of the phase transition from superfluid to normal states in the nucleus are analysed. The role of the second (dynamic) moment of inertia I(2) in this analysis is discussed. In spherical weekly deformed nuclei (mostly oblate) angular momentum is aligned parallel to the nuclear symmetry axis. Rotation is of non collective origin in this case. Examples of the analysis of nuclear spectra in this case (exhibiting also the isomeric states called yrast (traps)) are given. Possible forms of the collective excitations superimposed on top of the high-spin states are discussed. In particular, the giant resonance excitations formed on top of the high-spin states are considered and their properties discussed

  15. Correlated motions are a fundamental property of β-sheets

    Science.gov (United States)

    Fenwick, R. Bryn; Orellana, Laura; Esteban-Martín, Santi; Orozco, Modesto; Salvatella, Xavier

    2014-06-01

    Correlated motions in proteins can mediate fundamental biochemical processes such as signal transduction and allostery. The mechanisms that underlie these processes remain largely unknown due mainly to limitations in their direct detection. Here, based on a detailed analysis of protein structures deposited in the protein data bank, as well as on state-of-the art molecular simulations, we provide general evidence for the transfer of structural information by correlated backbone motions, mediated by hydrogen bonds, across β-sheets. We also show that the observed local and long-range correlated motions are mediated by the collective motions of β-sheets and investigate their role in large-scale conformational changes. Correlated motions represent a fundamental property of β-sheets that contributes to protein function.

  16. Extraction and Analysis of Respiratory Motion Using Wearable Inertial Sensor System during Trunk Motion

    Directory of Open Access Journals (Sweden)

    Apoorva Gaidhani

    2017-12-01

    Full Text Available Respiratory activity is an essential vital sign of life that can indicate changes in typical breathing patterns and irregular body functions such as asthma and panic attacks. Many times, there is a need to monitor breathing activity while performing day-to-day functions such as standing, bending, trunk stretching or during yoga exercises. A single IMU (inertial measurement unit can be used in measuring respiratory motion; however, breathing motion data may be influenced by a body trunk movement that occurs while recording respiratory activity. This research employs a pair of wireless, wearable IMU sensors custom-made by the Department of Electrical Engineering at San Diego State University. After appropriate sensor placement for data collection, this research applies principles of robotics, using the Denavit-Hartenberg convention, to extract relative angular motion between the two sensors. One of the obtained relative joint angles in the “Sagittal” plane predominantly yields respiratory activity. An improvised version of the proposed method and wearable, wireless sensors can be suitable to extract respiratory information while performing sports or exercises, as they do not restrict body motion or the choice of location to gather data.

  17. Effects of ship's vibration and motion on plant parameters

    International Nuclear Information System (INIS)

    Kakuta, Tsunemi; Kitamura, Toshikatsu; Mizushima, Toshihiko; Yamazaki, Hiroshi; Nakahara, Takeshi; Kamiya, Eisei; Kudou, Takahiro; Naitoh, Akira; Tominaga, Mineo.

    1992-03-01

    Present report was written about the study of the effects of ship's vibration and motion on reactor plant performances measured and analyzed to confirm the total balance for control systems of reactor to propulsion. On July 10, 1990, or on the first day of the first voyage for the power up test, the sea trials of MUTSU, nuclear ship made first in Japan, started from the anchoring test. The trial tests had finished through the third voyage between October 30 and November 9 to the fourth voyage between 7 and 14 of December. The trial tests had been conducted over ten items or so containing in-house tests of the measurements of ship's vibration and motion in order to research the effects on reactor performance. We here call the in-house tests the plant correlation tests. In regard to the correlation with ship's vibration, we confirmed that the inherent vibrations of hull and reactor containment arisen from ship structure had precisely been measured and that the plant correlations due to the hull and local vibrations arising from propeller revolutions are very small. Concerning the correlation with ship's motion, it was shown that her rolling motion strongly had affected on the propulsion system such as shaft power and shaft revolutions. About the correlation with reactor systems it was found that her pitching motion had given effect on the water level in pressurizer, primary coolant average temperature, ε-signal of the auto-control of reactor power and primary coolant pressure etc, particularly, most-strongly on the water level in pressurizer; her rolling and pitching motions had given effect on nuclear characteristics such as reactivity and startup rate; in addition the fluctuation of 0.06 Hz, we think the response inherent in (MUTSU) reactor systems, had been observed on her reactor parameters like reactivity and startup rate, and her propulsion systems like shaft horse power. (author)

  18. Summary of nuclear-excavation applications

    International Nuclear Information System (INIS)

    Toman, John

    1970-01-01

    Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

  19. Summary of nuclear-excavation applications

    Energy Technology Data Exchange (ETDEWEB)

    Toman, John [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

  20. Collection and treatment of reliability data for nuclear plants

    International Nuclear Information System (INIS)

    McHugh, B.

    1973-09-01

    This paper describes some of the results achieved with the Argus data bank at the Institution of Thermal Power Engineering at the Chalmers University of Technology. This data bank, or rather data collection system, has been established to cover nuclear activities the world over. The system comprises in essence a number of data files. The prime files are those containing the basic data on the various plants - plant size and type, country and NSSS supplier and an indication of plantstatus. Further files contain plant design data and parameters and all available information on construction as commissioning timetables. To cover the operation of plant two files have been established. One file, which is updated on a monthly basis, contains power production statistics. The other file contains failure data. In this file are recorded the time and duration of plant shutdown together with the primary reason (s) for this. (M.S.)

  1. Asymptotical approximation of interconnection of nucleons' quadrupole and cluster motion in atomic nucleus

    International Nuclear Information System (INIS)

    Kabulov, A.B.

    2003-01-01

    Atomic nuclei display different kinds of collective motion. The well known example - is the collective model arising from valent nucleons motion. The other a special kind of collective motion is cluster mode. If a collective model has quadrupole character, then cluster one has dipole character. In the boson formalism this model is describing by dynamic symmetry U(6) direct X U(4). The common Hamiltonian symmetrical to U(6) direct X U(4) group has a form H=H d +H p +V pd . In the paper the asymptotical wave function for dipole states connected with (N-1) bosons of s- and d-types is presented. In this case the problem for Hamiltonian eigenvalues is solving by analytical way. With use Elliot method and wave functions asymptotical form the operators for matrix elements of E2-, E1-, M1-transitions are cited

  2. Rotational motion in nuclei

    International Nuclear Information System (INIS)

    Bohr, A.

    1977-01-01

    History is surveyed of the development of the theory of rotational states in nuclei. The situation in the 40's when ideas formed of the collective states of a nucleus is evoked. The general rotation theory and the relation between the single-particle and rotational motion are briefly discussed. Future prospects of the rotation theory development are indicated. (I.W.)

  3. Nuclear power plant containment metallic pressure boundary materials and plans for collecting and presenting their properties

    International Nuclear Information System (INIS)

    Oland, C.B.

    1995-04-01

    A program is being conducted at the Oak Ridge National Laboratory (ORNL to assist the Nuclear Regulatory Commission (NRC)) in their assessment of the effects of degradation (primarily corrosion) on the structural capacity and leaktight integrity of metal containments and steel liners of reinforced concrete structures in nuclear power plants. One of the program objectives is to characterize and quantify manifestations of corrosion on the properties of steels used to construct containment pressure boundary components. This report describes a plan for use in collecting and presenting data and information on ferrous alloys permitted for use in construction of pressure retaining components in concrete and metal containments. Discussions about various degradation mechanisms that could potentially affect the mechanical properties of these materials are also included. Conclusions and recommendations presented in this report will be used to guide the collection of data and information that will be used to prepare a material properties data base for containment steels

  4. Nuclear sound

    International Nuclear Information System (INIS)

    Wambach, J.

    1991-01-01

    Nuclei, like more familiar mechanical systems, undergo simple vibrational motion. Among these vibrations, sound modes are of particular interest since they reveal important information on the effective interactions among the constituents and, through extrapolation, on the bulk behaviour of nuclear and neutron matter. Sound wave propagation in nuclei shows strong quantum effects familiar from other quantum systems. Microscopic theory suggests that the restoring forces are caused by the complex structure of the many-Fermion wavefunction and, in some cases, have no classical analogue. The damping of the vibrational amplitude is strongly influenced by phase coherence among the particles participating in the motion. (author)

  5. An Improved Methodology of Monetary Values of the Unit Collective Dose for Intervention Against Long-Term Exposure Following a Nuclear Accident

    International Nuclear Information System (INIS)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil; Han, Moon Hee

    2002-01-01

    A more practice approach for the determination of monetary values of the unit collective dose for intervention against long-term exposure following a nuclear accident was proposed. In addition, the monetary values of the unit collective dose estimated from the proposed approach were compared with those estimated from the previous model, which are derived from assumptions of routine exposure and the same values are applied in a nuclear accident without modification, using Korea economic data. The monetary values based on the proposed approach showed a distinct difference depending on inequity in the distribution of individual doses. The discounting rate was also an important factor in determination of monetary values of the unit collective dose

  6. An Improved Methodology of Monetary Values of the Unit Collective Dose for Intervention Against Long-Term Exposure Following a Nuclear Accident

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil; Han, Moon Hee [KAERI, Daejeon (Korea, Republic of)

    2002-06-15

    A more practice approach for the determination of monetary values of the unit collective dose for intervention against long-term exposure following a nuclear accident was proposed. In addition, the monetary values of the unit collective dose estimated from the proposed approach were compared with those estimated from the previous model, which are derived from assumptions of routine exposure and the same values are applied in a nuclear accident without modification, using Korea economic data. The monetary values based on the proposed approach showed a distinct difference depending on inequity in the distribution of individual doses. The discounting rate was also an important factor in determination of monetary values of the unit collective dose.

  7. Auditory Motion Elicits a Visual Motion Aftereffect.

    Science.gov (United States)

    Berger, Christopher C; Ehrsson, H Henrik

    2016-01-01

    The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect-an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

  8. Auditory Motion Elicits a Visual Motion Aftereffect

    Directory of Open Access Journals (Sweden)

    Christopher C. Berger

    2016-12-01

    Full Text Available The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect—an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

  9. On development and improvement of evaluation techniques for strong ground motion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    Issues regarding evaluation of active fault and ground motion for formulation of design basis ground motion (Ss) were identified during NISA and NSC seismic safety reviewing activities, which have been conducted in the light of the revision of the relevant seismic regulatory guide in 2006 and the experiences of the Niigataken Chuetsu-oki Earthquake in 2007 and the 2011 off the Pacific Coast of Tohoku Earthquake. In this theme following four subjects were investigated to resolve the important problems for ground motion evaluation, (1) advanced evaluation of ground motion using fault model and uncertainty; (2) improving evaluation of ground motion using attenuation relation of response spectrum; (3) development of advanced technique for ground motion observation and observation tool in deep borehole; (4) improving the evaluation of site effect and seismic wave propagation characteristics. Obtained results will be incorporated into the national safety review and also in the safety standard guidelines of the International Atomic Energy Agency (IAEA) using its Extra-Budgetary Program (IAEA EBP), thereby contributing to technical cooperation in global nuclear seismic safety. (author)

  10. French network and acquired experience on record strong ground motion

    International Nuclear Information System (INIS)

    Ferrieux, H.; Mohammadioun, G.

    1988-03-01

    The network intended to record strong ground motion in continental France is composed for the most part of instrument packages incorporated into nuclear installations, which are supplemented by a certain number of accelerometers placed in the most highly seismic areas. In a country where the level of seismicity is relatively modest, such a network is not conductive to the acquisition of new data, which, instead, is obtained through spot studies of limited duration using more sensitive instruments or through the recording of strong ground motion in neighbouring countries [fr

  11. Study on operation conditions and an operation system of a nuclear powered submersible research vessel, 'report of working group on application of a very small nuclear reactor to an ocean research'

    International Nuclear Information System (INIS)

    Ura, Tamaki; Takamasa, Tomoji; Nishimura, Hajime

    2001-07-01

    JAERI has studied on design of a nuclear powered submersible research vessel, which will navigate under sea mainly in the Arctic Ocean, as a part of the design activity of advanced marine reactors. This report describes operation conditions and an operating system of the vessel, which were discussed by the specialists of hull design, sound positioning, ship motions and oceanography, etc. The design conditions on ship motions for submersible vessels were surveyed considering regulations in our country, and ship motions were evaluated in the cases of underwater and surface navigations taking account of observation activities in the Arctic Ocean. The effect of ship motions on the compact nuclear reactor SCR was assessed. A submarine transponder system and an on-ice communication buoy system were examined as a positioning and communication system, supposing the activity under ice. The interval between transponders or communication buoys was recommended as 130 km. Procedures to secure safety of nuclear powered submersible research vessel were discussed according to accidents on the hull or the nuclear reactor. These results were reflected to the concept of the nuclear powered submersible research vessel, and subjects to be settled in the next step were clarified. (author)

  12. Motion planning for multiple robots

    NARCIS (Netherlands)

    Aronov, B.; Berg, de M.; van der Stappen, A.F.; Svestka, P.; Vleugels, J.M.

    1999-01-01

    We study the motion-planning problem for pairs and triples of robots operating in a shared workspace containing n obstacles. A standard way to solve such problems is to view the collection of robots as one composite robot, whose number of degrees of freedom is d , the sum of the numbers of degrees

  13. Distinguishing advective and powered motion in self-propelled colloids

    Science.gov (United States)

    Byun, Young-Moo; Lammert, Paul E.; Hong, Yiying; Sen, Ayusman; Crespi, Vincent H.

    2017-11-01

    Self-powered motion in catalytic colloidal particles provides a compelling example of active matter, i.e. systems that engage in single-particle and collective behavior far from equilibrium. The long-time, long-distance behavior of such systems is of particular interest, since it connects their individual micro-scale behavior to macro-scale phenomena. In such analyses, it is important to distinguish motion due to subtle advective effects—which also has long time scales and length scales—from long-timescale phenomena that derive from intrinsically powered motion. Here, we develop a methodology to analyze the statistical properties of the translational and rotational motions of powered colloids to distinguish, for example, active chemotaxis from passive advection by bulk flow.

  14. Collective motion in Proteus mirabilis swarms

    Science.gov (United States)

    Haoran, Xu

    Proteus mirabilisis a Gram-negative, rod-shaped bacterium. It is widely distributed in soil and water, and it is well known for exhibiting swarming motility on nutrient agar surfaces. In our study, we focused on the collective motility of P. mirabilis and uncovered a range of interesting phenomena. Here we will present our efforts to understand these phenomena through experiments and simulation. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail:xhrphx@gmail.com.

  15. Shaking Table Tests on the Seismic Behavior of Steel Frame Structures Subjected to Various Earthquake Ground Motions

    International Nuclear Information System (INIS)

    Choi, In Kil; Kim, Min Kyu; Choun, Young Sun; Seo, Jeong Moon

    2004-05-01

    The standard response spectrum proposed by US NRC has been used as a design earthquake for the design of Korean nuclear power plant structures. Recent large earthquakes occurred in near-fault zone have done significant damage and loss of life to earthquake area. A survey on some of the Quaternary fault segments near the Korean nuclear power plants is ongoing. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of the nuclear power plants located near the fault. In this study, the shaking table tests of three steel frame structures were performed. Three types of input motions, artificial time histories that envelop the US NRC Regulatory Guide 1.60 spectrum and the probability based scenario earthquake spectra developed for the Korean nuclear power plant site and a typical near-fault earthquake recorded at Chi-Chi earthquake, were used as input motions. The acceleration and displacement responses of the structure due to the design earthquake were larger than those due to the other input earthquakes. It seems that the design earthquake for the Korean nuclear power plants is conservative, and that the near-fault earthquake and scenario earthquake are not so damageable for the nuclear power plant structures, because the fundamental frequencies of the nuclear power plant structures are generally greater than 5 Hz. The high frequency ground motions that appeared in the scenario earthquake can be more damageable for the equipment installed on the high floors in a building. This means that the design earthquake is not so conservative for the safety of the safety related nuclear power plant equipment

  16. Nuclear energy

    International Nuclear Information System (INIS)

    Kuhn, W.

    1986-01-01

    This loose-leaf collection is made up of five didactically prepared units covering the following subjects: basic knowledge on nuclear energy, nuclear energy in relation to energy economy, site issues, environmental compatibility of nuclear energy, and nuclear energy in the focus of political and social action. To this was added a comprehensive collection of material: specific scientific background material, a multitude of tables, diagrams, charts etc. for copying, as well as 44 transparent charts, mostly in four colours. (orig./HP) [de

  17. Quantum chaos in nuclear single-particle motion and damping of giant resonances

    International Nuclear Information System (INIS)

    Pal, Santanu; Mukhopadhyay, Tapan

    1995-01-01

    The spectral statistics of single particle motion in deformed cavities with axial symmetry are presented. The single particle motion in the cavities considered are non-integrable and the systematics of the fluctuation measures of the spectra reveal a transition from regular to chaotic regime in the corresponding classical systems. Quantitative estimate of the degree of chaos enables us to introduce a correction factor to the one-body wall formula for the damping widths of isoscalar giant resonances. The damping widths calculated with this correction factor give much better agreement with experimental values than earlier calculations of one-body damping widths. (author). 21 refs., 5 figs

  18. Broad line and pulsed NMR study of molecular motion in furfuryl alcohol resins

    International Nuclear Information System (INIS)

    Glowinkowski, S.; Pajak, Z.

    1978-01-01

    Broad line and pulsed nuclear magnetic resonance studies are carried out on a number of furfuryl alcohol resins differentiated by viscosity. Proton NMR spectra and relaxation times T 1 and Tsub(1rho) are measured over a wide temperature range and the results are interpreted in terms of molecular motion. The marked decrease in second moment and existence of high temperature spin-lattice relaxation times minima are presumed to result from rotational motion of polymer chains. The relaxation processes at low temperature are believed to be due to rotational motion of methyl endgroup and paramagnetic centres. (author)

  19. g factors and the interplay of collective and single-particle degrees of freedom in superdeformed mass-190 nuclei

    International Nuclear Information System (INIS)

    Sun, Yang; Zhang, Jing-ye; Guidry, Mike

    2001-01-01

    Interplay of collective and single-particle degrees of freedom is a common phenomenon in strongly correlated many-body systems. Despite many successful efforts in the study of superdeformed nuclei, there is still unexplored physics that can be best understood only through the nuclear magnetic properties. We point out that study of the gyromagnetic factor (g factor) may open a unique opportunity for understanding superdeformed structure. Our calculations suggest that investigation of the g-factor dependence on spin and particle number can provide important information on single-particle structure and its interplay with collective motion in the superdeformed mass-190 nuclei. Modern experimental techniques combined with the new generation of sensitive detectors should be capable of testing our predictions

  20. Study on operation conditions and an operation system of a nuclear powered submersible research vessel, 'report of working group on application of a very small nuclear reactor to an ocean research'

    Energy Technology Data Exchange (ETDEWEB)

    Ura, Tamaki [Tokyo Univ., Tokyo (Japan); Takamasa, Tomoji [Tokyo Univ. of Mercantile Marine, Tokyo (Japan); Nishimura, Hajime [Japan Marine Science and Technology Center, Yokosuka, Kanagawa (JP)] [and others

    2001-07-01

    JAERI has studied on design of a nuclear powered submersible research vessel, which will navigate under sea mainly in the Arctic Ocean, as a part of the design activity of advanced marine reactors. This report describes operation conditions and an operating system of the vessel, which were discussed by the specialists of hull design, sound positioning, ship motions and oceanography, etc. The design conditions on ship motions for submersible vessels were surveyed considering regulations in our country, and ship motions were evaluated in the cases of underwater and surface navigations taking account of observation activities in the Arctic Ocean. The effect of ship motions on the compact nuclear reactor SCR was assessed. A submarine transponder system and an on-ice communication buoy system were examined as a positioning and communication system, supposing the activity under ice. The interval between transponders or communication buoys was recommended as 130 km. Procedures to secure safety of nuclear powered submersible research vessel were discussed according to accidents on the hull or the nuclear reactor. These results were reflected to the concept of the nuclear powered submersible research vessel, and subjects to be settled in the next step were clarified. (author)

  1. Inelastic response evaluation of steel frame structure subjected to near-fault ground motions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, In Kil; Kim, Hyung Kyu; Choun, Young Sun; Seo, Jeong Moon

    2004-04-01

    A survey on some of the Quaternary fault segments near the Korean nuclear power plants is ongoing. It is likely that these faults would be identified as active ones. If the faults are confirmed as active ones, it will be necessary to reevaluate the seismic safety of nuclear power plants located near the fault. This study was performed to acquire overall knowledge of near-fault ground motions and evaluate inealstic response characteristics of near-fault ground motions. Although Korean peninsular is not located in the strong earthquake region, it is necessary to evaluate seismic safety of NPP for the earthquakes occurred in near-fault area with characteristics different from that of general far-fault earthquakes in order to improve seismic safety of existing NPP structures and equipment. As a result, for the seismic safety evaluation of NPP structures and equipment considering near-fault effects, this report will give many valuable information. In order to improve seismic safety of NPP structures and equipment against near-fault ground motions, it is necessary to consider inelastic response characteristics of near-fault ground motions in current design code. Also in Korea where these studies are immature yet, in the future more works of near-fault earthquakes must be accomplished.

  2. Two-level convolution formula for nuclear structure function

    Science.gov (United States)

    Ma, Boqiang

    1990-05-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

  3. Two-level convolution formula for nuclear structure function

    International Nuclear Information System (INIS)

    Ma Boqiang

    1990-01-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions

  4. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1998-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors)

  5. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  6. Measurements of ground motion and magnet vibrations at the APS

    International Nuclear Information System (INIS)

    Shiltsev, V.

    1996-01-01

    This article presents results of ground motion and magnet vibrations measurements at the Advanced Photon Source. The experiments were done over a wide, frequency range (0-05-100 Hz) with the use of SM-3KV-type seismic probes from the Budker Institute of Nuclear Physics (Russia). Spectral power densities of vertical and horizontal motions of the APS hall floor and quadrupoles on regular supports were obtained. Also investigated were magnet vibrations induced by designed cooling water flow and spectral characteristics of spatial correlation of the quadrupole vibrations at different sectors of the ring. The influence of personnel activity in the hall and traffic under the ring on the slow motion of storage ring elements were observed. Amplitudes of vibrations at the APS are compared with results of seismic measurements at some other accelerators

  7. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1997-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author)

  8. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  9. French practice in the area of seismic hazard assessment on nuclear facility sites and related research

    International Nuclear Information System (INIS)

    Mohammadioun, B.

    1986-06-01

    The methodology put into practice in the analysis of seismic hazard on the site of a nuclear facility relies upon a deterministic approach and endeavors to account for the particularities of every site considered insofar as available data and techniques allow. The calculation of a seismic reference motion for use in the facilities' design calls upon two basic sets of data. Regional seismicity over the past millennium, from historical sources, revised while preparing the seismotectonic map of France, is fundamental to this analysis. It is completed by instrumental data from the last quarter century. A collection of strong-motion accelerograph data from seismic areas worldwide reflects a variety of source characteristics and site conditions. A critical overview of current practice in France and elsewhere highlights shortcomings and areas of particular need both in experimental data and in methodology, and namely the scarcity of near-field data, the predominance of California records, and inaccurate approaches to integrating soil effects into ground-motion calculations. 16 refs

  10. A triboelectric motion sensor in wearable body sensor network for human activity recognition.

    Science.gov (United States)

    Hui Huang; Xian Li; Ye Sun

    2016-08-01

    The goal of this study is to design a novel triboelectric motion sensor in wearable body sensor network for human activity recognition. Physical activity recognition is widely used in well-being management, medical diagnosis and rehabilitation. Other than traditional accelerometers, we design a novel wearable sensor system based on triboelectrification. The triboelectric motion sensor can be easily attached to human body and collect motion signals caused by physical activities. The experiments are conducted to collect five common activity data: sitting and standing, walking, climbing upstairs, downstairs, and running. The k-Nearest Neighbor (kNN) clustering algorithm is adopted to recognize these activities and validate the feasibility of this new approach. The results show that our system can perform physical activity recognition with a successful rate over 80% for walking, sitting and standing. The triboelectric structure can also be used as an energy harvester for motion harvesting due to its high output voltage in random low-frequency motion.

  11. Proposal for the rocking analysis model of the dry cask for spent nuclear fuel attached to the storage pallet subjected to the strong earthquake motions

    International Nuclear Information System (INIS)

    Kondo, Shunsuke; Shirai, Koji; Namba, Kosuke

    2016-01-01

    In Japan, a dry cask for spent nuclear fuel attached to a storage pallet should be transferred and stored in the vertical orientation on the concrete floor in an interim spent nuclear fuel storage facility at or outside reactor site, and a transfer system using air supply will be adopted for such pallet. In case of the hypothetical event, the shutdown of the air supply due to the strong earthquake motions, it is important to evaluate a stability of the metal cask on the concrete floor during seismic motions. A dynamic analysis by the analysis code 'TDAPIII' was executed with a simple lumped mass model by adopting joint elements between a concrete floor and pallet, to reproduce the rocking and sliding behavior. Joint stiffness values were equivalently set to the vibration modes obtained by an eigenvalue analysis. The seismic analysis results were compared with the previous shaking table test results with 2/5 scale model of a real size cask. As a result, although discrepancies of the velocity response of the converted from maximum uplifting potential energy appeared in the range of μ ± 3σ (0.57 ∼ 1.46) among 45 analysis cases comparing with experiment results, it was confirmed that maximum value was about 110kine considerably less than the overturning threshold value 190kine. Moreover, an applicability of the proposed prediction methodology to the real size model was also confirmed. (author)

  12. Nuclear cardiology

    International Nuclear Information System (INIS)

    Vos, P.H.

    1982-01-01

    This thesis deals with two topics in nuclear cardiology. In the first, left ventricular wall motion assessment using Fourier transform of local left ventricular time-activity curves in gated blood pool studies is evaluated. In the second, the interpretation of myocardial perfusion scintigrams is assessed which are obtained with thallium-201 or with another radiopharmaceutical with different physical, but identical biological properties. In all these investigations data acquisition and analysis by computer played an essential role. In chapter 1 the desirable properties of a nuclear medicine computer system are given and the computer system used for this work is described. Wall motion analysis of the left ventricle using Fourier transform of local time-activity curves in the left ventricular region in gated blood pool studies is described in chapter 2. In chapter 3 detection of non-perfused lesions in myocardial perfusion scintigraphy with thallium-201 is described. Detection of partly perfused lesions and the influence of scatter and photon energy on myocardial perfusion scintigraphy is described in chapter 4. (Auth.)

  13. Seismic hazard analysis. Review panel, ground motion panel, and feedback results

    International Nuclear Information System (INIS)

    Bernreuter, D.L.

    1981-10-01

    The Site Specific Spectra Project (SSSP) was a multi-year study funded by the U.S. Nuclear Regulatory Commission to provide estimates of the seismic hazards at a number of nuclear power plant sites in the Eastern U.S. A key element of our approach was the Peer Review Panel, which we formed in order to ensure that our use of expert opinion was reasonable. We discuss the Peer Review Panel results and provide the complete text of each member's report. In order to improve the ground motion model, an Eastern U.S. Ground Motion Model Panel was formed. In Section 4 we tabulate the responses from the panel members to our feedback questionnaire and discuss the implications of changes introduced by them. We conclude that the net difference in seismic hazard values from those presented in Volume 4 is small and does not warrant a reanalysis. (author)

  14. Reduction of vortex induced forces and motion through surface roughness control

    Science.gov (United States)

    Bernitsas, Michael M; Raghavan, Kamaldev

    2014-04-01

    Roughness is added to the surface of a bluff body in a relative motion with respect to a fluid. The amount, size, and distribution of roughness on the body surface is controlled passively or actively to modify the flow around the body and subsequently the Vortex Induced Forces and Motion (VIFM). The added roughness, when designed and implemented appropriately, affects in a predetermined way the boundary layer, the separation of the boundary layer, the level of turbulence, the wake, the drag and lift forces, and consequently the Vortex Induced Motion (VIM), and the fluid-structure interaction. The goal of surface roughness control is to decrease/suppress Vortex Induced Forces and Motion. Suppression is required when fluid-structure interaction becomes destructive as in VIM of flexible cylinders or rigid cylinders on elastic support, such as underwater pipelines, marine risers, tubes in heat exchangers, nuclear fuel rods, cooling towers, SPAR offshore platforms.

  15. Nuclear physics accelerator facilities of the world

    International Nuclear Information System (INIS)

    1991-12-01

    this report is intended to provide a convenient summary of the world's major nuclear physics accelerator facility with emphasis on those facilities supported by the US Department of Energy (DOE). Previous editions of this report have contained only DOE facilities. However, as the extent of global collaborations in nuclear physics grows, gathering summary information on the world's nuclear physics accelerator facilities in one place is useful. Therefore, the present report adds facilities operated by the National Science Foundation (NSF) as well as the leading foreign facilities, with emphasis on foreign facilities that have significant outside user programs. The principal motivation for building and operating these facilities is, of course, basic research in nuclear physics. The scientific objectives for this research were recently reviewed by the DOE/NSF Nuclear Science Advisory Committee, who developed a long range plan, Nuclei, Nucleons, and Quarks -- Nuclear Science in the 1990's. Their report begins as follows: The central thrust of nuclear science is the study of strongly interacting matter and of the forces that govern its structure and dynamics; this agenda ranges from large- scale collective nuclear behavior through the motions of individual nucleons and mesons, atomic nuclei, to the underlying distribution of quarks and gluons. It extends to conditions at the extremes of temperature and density which are of significance to astrophysics and cosmology and are conducive to the creation of new forms of strongly interacting matter; and another important focus is on the study of the electroweak force, which plays an important role in nuclear stability, and on precision tests of fundamental interactions. The present report provides brief descriptions of the accelerator facilities available for carrying out this agenda and their research programs

  16. 2001 Bhuj, India, earthquake engineering seismoscope recordings and Eastern North America ground-motion attenuation relations

    Science.gov (United States)

    Cramer, C.H.; Kumar, A.

    2003-01-01

    Engineering seismoscope data collected at distances less than 300 km for the M 7.7 Bhuj, India, mainshock are compatible with ground-motion attenuation in eastern North America (ENA). The mainshock ground-motion data have been corrected to a common geological site condition using the factors of Joyner and Boore (2000) and a classification scheme of Quaternary or Tertiary sediments or rock. We then compare these data to ENA ground-motion attenuation relations. Despite uncertainties in recording method, geological site corrections, common tectonic setting, and the amount of regional seismic attenuation, the corrected Bhuj dataset agrees with the collective predictions by ENA ground-motion attenuation relations within a factor of 2. This level of agreement is within the dataset uncertainties and the normal variance for recorded earthquake ground motions.

  17. Motion of the esophagus due to cardiac motion.

    Directory of Open Access Journals (Sweden)

    Jacob Palmer

    Full Text Available When imaging studies (e.g. CT are used to quantify morphological changes in an anatomical structure, it is necessary to understand the extent and source of motion which can give imaging artifacts (e.g. blurring or local distortion. The objective of this study was to assess the magnitude of esophageal motion due to cardiac motion. We used retrospective electrocardiogram-gated contrast-enhanced computed tomography angiography images for this study. The anatomic region from the carina to the bottom of the heart was taken at deep-inspiration breath hold with the patients' arms raised above their shoulders, in a position similar to that used for radiation therapy. The esophagus was delineated on the diastolic phase of cardiac motion, and deformable registration was used to sequentially deform the images in nearest-neighbor phases among the 10 cardiac phases, starting from the diastolic phase. Using the 10 deformation fields generated from the deformable registration, the magnitude of the extreme displacements was then calculated for each voxel, and the mean and maximum displacement was calculated for each computed tomography slice for each patient. The average maximum esophageal displacement due to cardiac motion for all patients was 5.8 mm (standard deviation: 1.6 mm, maximum: 10.0 mm in the transverse direction. For 21 of 26 patients, the largest esophageal motion was found in the inferior region of the heart; for the other patients, esophageal motion was approximately independent of superior-inferior position. The esophagus motion was larger at cardiac phases where the electrocardiogram R-wave occurs. In conclusion, the magnitude of esophageal motion near the heart due to cardiac motion is similar to that due to other sources of motion, including respiratory motion and intra-fraction motion. A larger cardiac motion will result into larger esophagus motion in a cardiac cycle.

  18. Collective motion with anticipation: flocking, spinning, and swarming.

    Science.gov (United States)

    Morin, Alexandre; Caussin, Jean-Baptiste; Eloy, Christophe; Bartolo, Denis

    2015-01-01

    We investigate the collective dynamics of self-propelled particles able to probe and anticipate the orientation of their neighbors. We show that a simple anticipation strategy hinders the emergence of homogeneous flocking patterns. Yet anticipation promotes two other forms of self-organization: collective spinning and swarming. In the spinning phase, all particles follow synchronous circular orbits, while in the swarming phase, the population condensates into a single compact swarm that cruises coherently without requiring any cohesive interactions. We quantitatively characterize and rationalize these phases of polar active matter and discuss potential applications to the design of swarming robots.

  19. Nuclear morphometry in histological specimens of canine prostate cancer: Correlation with histological subtypes, Gleason score, methods of collection and survival time.

    Science.gov (United States)

    Di Donato, Guido; Laufer-Amorim, Renée; Palmieri, Chiara

    2017-10-01

    Ten normal prostates, 22 benign prostatic hyperplasia (BPH) and 29 prostate cancer (PC) were morphometrically analyzed with regard to mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear diameter (MND), coefficient of variation of the nuclear area (NACV), mean nuclear diameter maximum (MDx), mean nuclear diameter minimum (MDm), mean nuclear form ellipse (MNFe) and form factor (FF). The relationship between nuclear morphometric parameters and histological type, Gleason score, methods of sample collection, presence of metastases and survival time of canine PC were also investigated. Overall, nuclei from neoplastic cells were larger, with greater variation in nuclear size and shape compared to normal and hyperplastic cells. Significant differences were found between more (small acinar/ductal) and less (cribriform, solid) differentiated PCs with regard to FF (pnuclear morphometric analysis in combination with Gleason score can help in canine prostate cancer grading, thus contributing to the establishment of a more precise prognosis and patient's management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane.

    Science.gov (United States)

    Rosenblatt, Steven David; Crane, Benjamin Thomas

    2015-01-01

    A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37) participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s) at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001) and rotation (pperception was shifted in the direction consistent with the visual stimulus. Arrows had a small effect on self-motion

  1. Universal CNC platform motion control technology for industrial CT

    International Nuclear Information System (INIS)

    Cheng Senlin; Wang Yang

    2011-01-01

    According to the more scanning methods and the higher speed of industrial CT, the higher precision of the motion location and the data collection sync-control is required at present, a new motion control technology was proposed, which was established based on the universal CNC system with high precision of multi-axis control. Aiming at the second and the third generation of CT scanning motion, a control method was researched, and achieved the demands of the changeable parameters and network control, Through the simulation of the second and the third generation of CT scanning motion process, the control precision of the rotation axis reached 0.001° and the linear axis reached 0.002 mm, Practical tests showed this system can meet the requirements of the multi-axis motion integration and the sync signal control, it also have advantages in the control precision and the performance. (authors)

  2. Cohesive motion in one-dimensional flocking

    International Nuclear Information System (INIS)

    Dossetti, V

    2012-01-01

    A one-dimensional rule-based model for flocking, which combines velocity alignment and long-range centering interactions, is presented and studied. The induced cohesion in the collective motion of the self-propelled agents leads to unique group behavior that contrasts with previous studies. Our results show that the largest cluster of particles, in the condensed states, develops a mean velocity slower than the preferred one in the absence of noise. For strong noise, the system also develops a non-vanishing mean velocity, alternating its direction of motion stochastically. This allows us to address the directional switching phenomenon. The effects of different sources of stochasticity on the system are also discussed. (paper)

  3. Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane.

    Directory of Open Access Journals (Sweden)

    Steven David Rosenblatt

    Full Text Available A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37 participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001 and rotation (p0.1 for both. Thus, although a true moving visual field can induce self-motion, results of this

  4. The theory of collective motion probed by light

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M.Ya. [The Blackett Laboratory, Imperial College of Science, Technology and Medicine, London (United Kingdom); Racah Institute of Physics, Hebrew University, Jerusalem (Israel); Connerade, J.-P. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

    2000-01-01

    A review of collective phenomena in atomic and quasi-atomic systems is presented. The fundamental unity of the subject is stressed by appealing to a simple conceptual scheme, namely the Landau theory of wave propagation applied to a Fermi fluid. Collective giant resonances in nuclei, atoms, metallic clusters and fullerenes are all discussed and related to each other. Single-photon dipole, two-photon and quadrupole excitation are considered, as well as the observation of harmonics, and the enhancement of double excitations by a giant resonance. Other near-threshold phenomena are discussed, and experiments involving strong-field lasers are also considered in this context. (author)

  5. Measurements of ground motion and magnets vibrations at the APS

    International Nuclear Information System (INIS)

    Shil'tsev, V.D.

    1994-01-01

    This article presents results of ground motion and magnets vibrations measurements at the Advanced Photon Source. The experiments were done over wide frequency range 0.05-100 Hz with use of SM-3KV type seismic probes from Budker Institute of Nuclear Physics (Russia). Spectral power densities of vertical and horizontal motions of the APS hall floor and quadrupoles on regular supports were obtained. There were also investigated magnets vibrations induced by designed cooling water flow and spectral characteristics of spatial correlation of the quads vibration at different sectors of the ring. Influence of personnel activity in the hall and traffic under the ring on slow motion of storage ring elements were observed. Amplitudes of vibrations at the APS are compared with results of seismic measurements at some other accelerators. 9 refs.; 10 figs.; 1 tab

  6. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    International Nuclear Information System (INIS)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N.; Ukita, G.M.

    2004-01-01

    The study of the odd 99,101 Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in 100,102,104 Ru. Angular distributions for the 99,101 Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of Jπ = 5=2 + , 7=2 + and 9=2 + . Through the comparison of experimental and predicted cross section angular distributions, the values of (δ L N ) 2 and of the ratio C = δ L C /δ L N were obtained. (author)

  7. Strong motion duration and earthquake magnitude relationships

    International Nuclear Information System (INIS)

    Salmon, M.W.; Short, S.A.; Kennedy, R.P.

    1992-06-01

    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ''strong motion duration'' has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions

  8. The 2011 Mineral, VA M5.8 Earthquake Ground Motions and Stress Drop: An Important Contribution to the NGA East Ground Motion Database

    Science.gov (United States)

    Cramer, C. H.; Kutliroff, J.; Dangkua, D.

    2011-12-01

    The M5.8 Mineral, Virginia earthquake of August 23, 2011 is the largest instrumentally recorded earthquake in eastern North America since the 1988 M5.9 Saguenay, Canada earthquake. Historically, a similar magnitude earthquake occurred on May 31, 1897 at 18:58 UCT in western Virginia west of Roanoke. Paleoseismic evidence for larger magnitude earthquakes has also been found in the central Virginia region. The Next Generation Attenuation (NGA) East project to develop new ground motion prediction equations for stable continental regions (SCRs), including eastern North America (ENA), is ongoing at the Pacific Earthquake Engineering Research Center funded by the U.S. Nuclear Regulatory Commission, the U.S. Geological Survey, the Electric Power Research Institute, and the U.S. Department of Energy. The available recordings from the M5.8 Virginia are being added to the NGA East ground motion database. Close in (less than 100 km) strong motion recordings are particularly interesting for both ground motion and stress drop estimates as most close-in broadband seismometers clipped on the mainshock. A preliminary estimate for earthquake corner frequency for the M5.8 Virginia earthquake of ~0.7 Hz has been obtained from a strong motion record 57 km from the mainshock epicenter. For a M5.8 earthquake this suggests a Brune stress drop of ~300 bars for the Virginia event. Very preliminary comparisons using accelerometer data suggest the ground motions from the M5.8 Virginia earthquake agree well with current ENA ground motion prediction equations (GMPEs) at short periods (PGA, 0.2 s) and are below the GMPEs at longer periods (1.0 s), which is the same relationship seen from other recent M5 ENA earthquakes. We will present observed versus GMPE ground motion comparisons for all the ground motion observations and stress drop estimates from strong motion recordings at distances less than 100 km. A review of the completed NGA East ENA ground motion database will also be provided.

  9. Art in Motion: A Sailboat Regatta

    Science.gov (United States)

    Angle, Julie; Foster, Gayla

    2011-01-01

    The activity described here uses the creative natures of visual art and music to enhance students' potential for creativity while increasing their understanding of the science associated with force and motion. Students design, test, and redesign a sailboat vehicle; collect data; make interpretations; and then defend their design. Music is used to…

  10. The doctor and nuclear warfare

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    At the 34th World Medical Assembly in Lisbon in 1981 the World Medical Association adopted a motion proposed by the American Medical Association that national medical associations should develop programs to educate the civilian population on the medical consequences of nuclear war. This article discusses the attitude the medical professions should have, should nuclear warfare in some form confront them in the future. The conclusion is drawn that defence against nuclear warfare is only a part of civil defence against any disaster, including the natural disasters such as flood and fire and the man-made disasters of transport accidents, even of problems at nuclear plants designed to supply energy

  11. Statistical analysis of earthquake ground motion parameters

    International Nuclear Information System (INIS)

    1979-12-01

    Several earthquake ground response parameters that define the strength, duration, and frequency content of the motions are investigated using regression analyses techniques; these techniques incorporate statistical significance testing to establish the terms in the regression equations. The parameters investigated are the peak acceleration, velocity, and displacement; Arias intensity; spectrum intensity; bracketed duration; Trifunac-Brady duration; and response spectral amplitudes. The study provides insight into how these parameters are affected by magnitude, epicentral distance, local site conditions, direction of motion (i.e., whether horizontal or vertical), and earthquake event type. The results are presented in a form so as to facilitate their use in the development of seismic input criteria for nuclear plants and other major structures. They are also compared with results from prior investigations that have been used in the past in the criteria development for such facilities

  12. Nuclear signals in magnetically ordered media

    International Nuclear Information System (INIS)

    Ignatchenko, V.A.; Tsifrinovich, V.I.

    1993-01-01

    The book contains a review of theoretical and experimental investigations in the field of nuclear magnetism in magnetically ordered media. The semiclassical theory of nuclear spins motion is developed that takes into consideration three main features of magnetically ordered media: Suhl-Nakamura interaction, quadrupole interaction and microscopic inhomogeneity of nuclear frequencies. The detailed classification of nuclear spin echo signals is given for standard conditions of experiments, when the Suhl-Nakamura interaction is small in comparison with the NMR line width. The extremal states of the electron - nuclear magnetic system are described in detail: the coexistence of NMR and FMR, nuclear ferromagnetism and NMR at fast remagnetization of a ferromagnet. 157 refs., 20 figs

  13. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    Science.gov (United States)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  14. Motions and electrostatic interactions in natural and semisynthetic myoglobins: a carbon-13 nuclear magnetic resonance study

    International Nuclear Information System (INIS)

    Maskalick, D.G.

    1984-01-01

    It is expected that the internal motions of amino acid side chains and protein backbone segments influence and are in turn affected by charge-charge and related interactions, steric constraints, hydrophobic forces, and hydrogen bonding. As an initial test of this theory 13 C-enriched glycine, alanine, and isoleucine have been substituted for the amino terminal valine of sperm whale myoglobin using semisynthetic techniques. 13 C-NMR has been used to analyze the motions of the side chain and the protonation state of the alpha amino group as a function of pH. The addition of a single methyl group to the side chain can alter the alpha amino pK value by as much as 0.3 pH units indicating a delicately balanced set of change-charge interactions between the alpha amino group and the rest of the protein. Further evidence in support of the state theory was found upon examination of the internal motions of seven of nine isoleucine vectors. These motions were extracted from natural abundance 13 C-NMR relaxation data. The results suggest a strong possibility that concerted motions are important. Also, an increase in temperature from 32 0 C to 52 0 C leads to an electrostatically driven tightening of the myoglobin structure as evidenced by no significant increase in motion amplitude of most of the vectors

  15. Seismic design criteria for nuclear powerplants

    International Nuclear Information System (INIS)

    Jennings, P.C.; Guzman, R.A.

    1975-01-01

    There are three main aspects of the problem of selection of seismic design criteria for major projects such as nuclear power plants. These are the description of the appropriate level of shaking to be considered, usually given in the form of design spectra; the allowable response of the structure, usually specified in terms of allowable stresses and deflections; and the capability of the structure to dissipate energy, commonly given in the form of fractions of critical damping. In this presentation only the first of these features is examined, with particular application to nuclear power plants. Under these restrictions, the most important parts of the problem become the determination of the amplitude of the design spectra corresponding to the safe shutdown earthquake (SSE) and the question of whether the shape of the spectra recommended by Regulatory Guide 1.60 (U. S. Atomic Energy Commission, 1973) is appropriate for the particular application. In the course of working out the details of the approach, it was found useful to reexamine a number of concepts including the use of response spectra or peak values of ground motion parameters, the shape of the design spectra, problems in attenuation and scaling, and the use of motions on the ground surface or bedrock motions. There is nothing fundamentally new in the suggested approach, although some of the features may not have been applied to the problem of selecting design spectra for nuclear power plants in the way suggested. The approach is applied only to nuclear power plants but it is not limited to this application

  16. Nuclear spin-isospin excitations from covariant quasiparticle-vibration coupling

    Science.gov (United States)

    Robin, Caroline; Litvinova, Elena

    2016-09-01

    Methods based on the relativistic Lagrangian of quantum hadrodynamics and nuclear field theory provide a consistent framework for the description of nuclear excitations, naturally connecting the high- and medium-energy scales of mesons to the low-energy domain of nucleonic collective motion. Applied in the neutral channel, this approach has been quite successful in describing the overall transition strength up to high excitation energies, as well as fine details of the low-lying distribution. Recently, this method has been extended to the description of spin-isospin excitations in open-shell nuclei. In the charge-exchange channel, the coupling between nucleons and collective vibrations generates a time-dependent proton-neutron effective interaction, in addition to the static pion and rho-meson exchange, and introduces complex configurations that induce fragmentation and spreading of the resonances. Such effects have a great impact on the quenching of the strength and on the computing of weak reaction rates that are needed for astrophysics modeling. Gamow-Teller transitions in medium-mass nuclei and associated beta-decay half-lives will be presented. Further developments aiming to include additional ground-state correlations will also be discussed. This work is supported by US-NSF Grants PHY-1404343 and PHY-1204486.

  17. 78 FR 73211 - Agency Information Collection Activities: Proposed Collection; Comment Request

    Science.gov (United States)

    2013-12-05

    ... Education Grants. The survey will allow the NRC to collect information that is not otherwise available from... minimized, including the use of automated collection techniques or other forms of information technology... NUCLEAR REGULATORY COMMISSION [NRC-2013-0256] Agency Information Collection Activities: Proposed...

  18. Real-time motion analytics during brain MRI improve data quality and reduce costs.

    Science.gov (United States)

    Dosenbach, Nico U F; Koller, Jonathan M; Earl, Eric A; Miranda-Dominguez, Oscar; Klein, Rachel L; Van, Andrew N; Snyder, Abraham Z; Nagel, Bonnie J; Nigg, Joel T; Nguyen, Annie L; Wesevich, Victoria; Greene, Deanna J; Fair, Damien A

    2017-11-01

    Head motion systematically distorts clinical and research MRI data. Motion artifacts have biased findings from many structural and functional brain MRI studies. An effective way to remove motion artifacts is to exclude MRI data frames affected by head motion. However, such post-hoc frame censoring can lead to data loss rates of 50% or more in our pediatric patient cohorts. Hence, many scanner operators collect additional 'buffer data', an expensive practice that, by itself, does not guarantee sufficient high-quality MRI data for a given participant. Therefore, we developed an easy-to-setup, easy-to-use Framewise Integrated Real-time MRI Monitoring (FIRMM) software suite that provides scanner operators with head motion analytics in real-time, allowing them to scan each subject until the desired amount of low-movement data has been collected. Our analyses show that using FIRMM to identify the ideal scan time for each person can reduce total brain MRI scan times and associated costs by 50% or more. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Investigating student understanding of simple harmonic motion

    Science.gov (United States)

    Somroob, S.; Wattanakasiwich, P.

    2017-09-01

    This study aimed to investigate students’ understanding and develop instructional material on a topic of simple harmonic motion. Participants were 60 students taking a course on vibrations and wave and 46 students taking a course on Physics 2 and 28 students taking a course on Fundamental Physics 2 on the 2nd semester of an academic year 2016. A 16-question conceptual test and tutorial activities had been developed from previous research findings and evaluated by three physics experts in teaching mechanics before using in a real classroom. Data collection included both qualitative and quantitative methods. Item analysis and whole-test analysis were determined from student responses in the conceptual test. As results, most students had misconceptions about restoring force and they had problems connecting mathematical solutions to real motions, especially phase angle. Moreover, they had problems with interpreting mechanical energy from graphs and diagrams of the motion. These results were used to develop effective instructional materials to enhance student abilities in understanding simple harmonic motion in term of multiple representations.

  20. Relativistic nuclear collisions: theory

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1980-07-01

    Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures

  1. The Role of Motion Concepts in Understanding Non-Motion Concepts

    Directory of Open Access Journals (Sweden)

    Omid Khatin-Zadeh

    2017-12-01

    Full Text Available This article discusses a specific type of metaphor in which an abstract non-motion domain is described in terms of a motion event. Abstract non-motion domains are inherently different from concrete motion domains. However, motion domains are used to describe abstract non-motion domains in many metaphors. Three main reasons are suggested for the suitability of motion events in such metaphorical descriptions. Firstly, motion events usually have high degrees of concreteness. Secondly, motion events are highly imageable. Thirdly, components of any motion event can be imagined almost simultaneously within a three-dimensional space. These three characteristics make motion events suitable domains for describing abstract non-motion domains, and facilitate the process of online comprehension throughout language processing. Extending the main point into the field of mathematics, this article discusses the process of transforming abstract mathematical problems into imageable geometric representations within the three-dimensional space. This strategy is widely used by mathematicians to solve highly abstract and complex problems.

  2. Quantal and thermal zero point motion formulae of barrier transmission probability

    International Nuclear Information System (INIS)

    Takigawa, N.; Alhassid, Y.; Balantekin, A.B.

    1992-01-01

    A Green's function method is developed to derive quantal zero point motion formulae for the barrier transmission probability in heavy ion fusion reactions corresponding to various nuclear intrinsic degrees of freedom. In order to apply to the decay of a hot nucleus, the formulae are then generalized to the case where the intrinsic degrees of freedom are in thermal equilibrium with a heat bath. A thermal zero point motion formula for vibrational coupling previously obtained through the use of influence functional methods naturally follows, and the effects of rotational coupling are found to be independent of temperature if the deformation is rigid

  3. Nuclear law in motion. Report on the 15th regional meeting of the German section of AIDN/INLA e.V; Atomrecht in Bewegung. Bericht ueber die 15. Regionaltagung der Deutschen Landesgruppe der AIDN/INLA e.V.

    Energy Technology Data Exchange (ETDEWEB)

    Feldmann, Ulrike

    2017-11-15

    For the 15th time the German National Group of the Association Internationale du Droit Nucleaire/International Nuclear Law Association (AIDN/IN-LA) e.V. organised a regional conference. 90 participants from 15 countries, including representatives of Euratom and OECD/NEA, met in Bonn on 28 and 29 September to exchange views on current issues of nuclear law. The Rhine, which was in sight of the conference centre and connects countries, provided an excellent backdrop not only for the conference that connects nations, but also for the title of the conference ''Atomic Energy Law in Motion'' and for various lectures on nuclear transport.

  4. Coherent Motion Reveals Non‐Ergodic Nature of Internal Conversion between Excited States

    DEFF Research Database (Denmark)

    Kuhlman, Thomas Scheby; Sølling, Theis I.; Møller, Klaus Braagaard

    2012-01-01

    for smaller molecules. Specifically, we focus on the S2→S1 internal conversion in cyclobutanone, cyclopentanone, and cyclohexanone. By means of time‐resolved mass spectrometry and photoelectron spectroscopy the relative rate of this transition is determined to be 13:2:1. Remarkably, we observe coherent......We found that specific nuclear motion along low‐frequency modes is effective in coupling electronic states and that this motion prevail in some small molecules. Thus, in direct contradiction to what is expected based on the standard models, the internal conversion process can proceed faster...

  5. Restoration and functional analysis of nuclear medicine images

    International Nuclear Information System (INIS)

    Wendt, R.E. III.

    1982-01-01

    The nuclear medicine physician uses visual interpretation of a movie-like display of the beating human heart to detect wall motion abnormalities which might be related to impaired cardiac function. The present work is directed toward extracting more information from the heart motion study, and presenting it in a useful manner. A spatially adaptive smoothing routine using a quadtree image representation gives an improvement in mean squared error compared to the S9 smoother commonly used for nuclear medicine studies. Functional images show the two-dimensional distribution of parameters of the heart motion. The most popular, the first harmonic phase functional image, formed from the first Fourier harmonic fit to each pixel time-activity curve, is subject to significant artifacts which make a simple interpretation of it difficult. A multi-harmonic approximation is more accurate and offers a wealth of unique parameters with which to construct more directly meaningful functional images

  6. Gait Recognition Using Wearable Motion Recording Sensors

    Directory of Open Access Journals (Sweden)

    Davrondzhon Gafurov

    2009-01-01

    Full Text Available This paper presents an alternative approach, where gait is collected by the sensors attached to the person's body. Such wearable sensors record motion (e.g. acceleration of the body parts during walking. The recorded motion signals are then investigated for person recognition purposes. We analyzed acceleration signals from the foot, hip, pocket and arm. Applying various methods, the best EER obtained for foot-, pocket-, arm- and hip- based user authentication were 5%, 7%, 10% and 13%, respectively. Furthermore, we present the results of our analysis on security assessment of gait. Studying gait-based user authentication (in case of hip motion under three attack scenarios, we revealed that a minimal effort mimicking does not help to improve the acceptance chances of impostors. However, impostors who know their closest person in the database or the genders of the users can be a threat to gait-based authentication. We also provide some new insights toward the uniqueness of gait in case of foot motion. In particular, we revealed the following: a sideway motion of the foot provides the most discrimination, compared to an up-down or forward-backward directions; and different segments of the gait cycle provide different level of discrimination.

  7. A novel approach for fast scanning of nuclear emulsions with continuous motion of the microscope stage

    Energy Technology Data Exchange (ETDEWEB)

    Aleksandrov, A., E-mail: andrey@na.infn.it [INFN sezione di Napoli, I-80125 Napoli (Italy); LPI - Lebedev Physical Institute of the Russian Academy of Sciences, RUS-119991 Moscow (Russian Federation); Tioukov, V. [INFN sezione di Napoli, I-80125 Napoli (Italy)

    2013-08-01

    Nuclear emulsions have been used in particle physics experiments for many decades because of their unique spatial resolution. The use of nuclear emulsions as precise tracking detectors in large experiments has recently been made possible due to advances in the production of emulsion films and to the development of very fast automatic scanning devices. The present scanning speed of the European Scanning System (ESS), which has been developed within the OPERA Collaboration, is about 20 cm{sup 2}/h. In addition to the scanning of OPERA films, the ESS is used for other applications with ever-growing demands for scanning speed, such as the muon radiography of volcanoes. In order to further increase the scanning speed of the ESS, we are testing a novel approach different from the standard stop-and-go motion of the microscope stage in the horizontal plane. Indeed we perform data acquisition with the stage moving at constant speed, using an objective lens with wide field of view. Unlike the implementation realized in Japan where the movement of objective lens and stage are synchronized to pile up images of the same view in a vertical stack, in this approach only the stage is moving horizontally. Thus images at different depths are not fully overlapped and special care is needed in the reconstruction. This approach can give a substantial increase in the scanning speed, especially for thin emulsion layers and wide field of view. In this paper we demonstrate that, after applying special corrections, the emulsion data quality can be as good as with the standard stop-and-go approach. This technique allows to double the scanning speed of the ESS, bringing it to 40 cm{sup 2}/h without any hardware modification.

  8. The quantum mechanical measuring process as a scattering phenomenon inducing a collective coherent motion

    International Nuclear Information System (INIS)

    Requardt, M.

    1984-01-01

    In this paper we want to discuss the quantum mechanical measuring process within the realm of many body quantum theory. Our starting point is to consider this process as a special scattering phenomenon where within one of the partners, i.e. the many body measuring device, a collective coherent motion is induced by the interaction with the microobject. We start our investigation with the many body system having a large but finite number N of degrees of freedom which is the real situation. We then study in detail what will happen in the limit N->infinite, however emphasizing that this transition is actually only performed in the mind of the observer. This implies that certain tail events together with their phase correlations have to be truncated. We show that the dichotomy 'pure state' versus 'mixture' as outgoing scattering states will vanish in this limit in so far as it has no observable consequences provided one is only interested in the state of the microobject. Furthermore, we discuss the role of the observer, the notion of 'event', the relation between single preparation and ensemble picture, and the so-called 'reduction of the wave function' in the light of our approach, i.e. explaining the phenomena accompanying the measuring process in terms of many body quantum theory. (orig.)

  9. The effect of high-frequency ground motion on the MAPLE-X10 reactor

    International Nuclear Information System (INIS)

    Bhan, S.; Dunbar, S.

    1989-06-01

    The effect of high-frequency ground motion on structures and equipment in nuclear reactors is examined by subjecting simple linear models to selected recorded ground motions which exhibit low and high frequencies. Computed damage measures indicate that high-frequency short-duration ground motion, such as that observed in eastern North America, have a minimal effect on structures with low natural frequencies. Response spectra of high-frequency ground motion indicate that higher forces are induced in structures with high natural frequencies as compared to those induced by low-frequency ground motion. However, reported observations of earthquake damage in eastern North America suggest that high-frequency ground motion causes little of no damage to structures. This may be due to the energy absorption capability of structures. It is concluded that the response spectrum representative of ground motion observed in eastern North America may give an over-conservative measure of the response of structures with high natural frequencies, since it does not account for the typically observed short duration of high-frequency ground motion and for the energy absorption capability of structures. Detailed nonlinear analysis of specific structures with high natural frequencies should be performed to better predict the actual response. Recommendations for a nonlinear analysis of typical structures with high natural frequencies are made

  10. Production of a diffuse very high reflectivity material for light collection in nuclear detectors

    CERN Document Server

    Pichler, B J; Mirzoyan, R; Weiss, L; Ziegler, S I

    2000-01-01

    A diffuse very high reflectivity material, based on polytetrafluorethylene (PTFE) for optimization of light-collection efficiency has been developed. PTFE powder was used to produce reflector block material. The powder was pressed with 525 kPa in a form and sintered at 375 deg. C. The reflectivity was above 98% within the spectral range from 350 to 1000 nm. The blocks of this material are machinable with saws, drilling and milling machines. The reflector is used as a housing for scintillating crystals in a nuclear medicine application (small animal positron emission tomograph). It is also used as a light collector in very high-energy gamma-ray astrophysicas experiments, HEGRA and MAGIC. The application of this inexpensive, easy to make diffuse reflector may allow the optimization of light collection in a wide range of low-level light-detector configurations.

  11. Authentication and Interpretation of Weight Data Collected from Accountability Scales at Global Nuclear Fuels

    International Nuclear Information System (INIS)

    Fitzgerald, Peter; Laughter, Mark D.; Martyn, Rose; Richardson, Dave; Rowe, Nathan C.; Pickett, Chris A.; Younkin, James R.; Shephard, Adam M.

    2010-01-01

    Accountability scale data from the Global Nuclear Fuels (GNF) fuel fabrication facility in Wilmington, NC has been collected and analyzed as a part of the Cylinder Accountability and Tracking System (CATS) field trial in 2009. The purpose of the data collection was to demonstrate an authentication method for safeguards applications, and the use of load cell data in cylinder accountability. The scale data was acquired using a commercial off-the-shelf communication server with authentication and encryption capabilities. The authenticated weight data was then analyzed to determine facility operating activities. The data allowed for the determination of the number of full and empty cylinders weighed and the respective weights along with other operational activities. Data authentication concepts, practices and methods, the details of the GNF weight data authentication implementation and scale data interpretation results will be presented.

  12. Structure of vibrational and rotational nuclei

    International Nuclear Information System (INIS)

    Otsuka, Takaharu

    1980-01-01

    The nuclear collective motion is discussed in terms of the Interacting Boson Model (IBM). Results of phenomenological studies by the IBM are presented, and the relation between the IBM and the geometrical models such as the vibration model, the rotor model, etc., is pointed out. A microscopic picture for the IBM is shown, in which bosons are introduced as a tool to describe the motion of nucleon pairs. It is emphasized that the IBM can give a unified understanding of the nuclear collective motion. (author)

  13. Aiming at the rebirth of the nuclear generation

    International Nuclear Information System (INIS)

    Uematsu, M.M.

    2000-01-01

    A half century has passed since Japan began an industrialization of nuclear energy. The nuclear industries of today have a variety of branches and each industry functions independently. Young professionals need opportunities for communications among industries, utilities and institutes, and also nuclear experts. We, young professionals, are in the motion of organizing the 'Young Generation Network (YGN) of Japan,' and also foresee to organize 'YGN in Asia' in the future

  14. On connection of rotation and internal motion in deformed nuclei

    International Nuclear Information System (INIS)

    Krutov, V.A.

    1979-01-01

    In the semiphenomenological nuclear madel (SPNM) the problem of ''overestimate of Coriolis interaction'' is shown to be easily solved. The rotation and internal motion coupling operator H(rot/in) is used. Overdetermination of the operator H(rot/in) has been generalized and extended into schemes of strong and weak coupling. In this case both schemes of coupling are transformed from approximate into precise ones and become applicable for any nuclear deformation. As examples of application of the theory considered are the matrix elements of the E2-transitions and inertia parameters of a 235 U nucleus

  15. Microscopic theory of nuclear fission: a review

    Science.gov (United States)

    Schunck, N.; Robledo, L. M.

    2016-11-01

    This article reviews how nuclear fission is described within nuclear density functional theory. A distinction should be made between spontaneous fission, where half-lives are the main observables and quantum tunnelling the essential concept, and induced fission, where the focus is on fragment properties and explicitly time-dependent approaches are often invoked. Overall, the cornerstone of the density functional theory approach to fission is the energy density functional formalism. The basic tenets of this method, including some well-known tools such as the Hartree-Fock-Bogoliubov (HFB) theory, effective two-body nuclear potentials such as the Skyrme and Gogny force, finite-temperature extensions and beyond mean-field corrections, are presented succinctly. The energy density functional approach is often combined with the hypothesis that the time-scale of the large amplitude collective motion driving the system to fission is slow compared to typical time-scales of nucleons inside the nucleus. In practice, this hypothesis of adiabaticity is implemented by introducing (a few) collective variables and mapping out the many-body Schrödinger equation into a collective Schrödinger-like equation for the nuclear wave-packet. The region of the collective space where the system transitions from one nucleus to two (or more) fragments defines what are called the scission configurations. The inertia tensor that enters the kinetic energy term of the collective Schrödinger-like equation is one of the most essential ingredients of the theory, since it includes the response of the system to small changes in the collective variables. For this reason, the two main approximations used to compute this inertia tensor, the adiabatic time-dependent HFB and the generator coordinate method, are presented in detail, both in their general formulation and in their most common approximations. The collective inertia tensor enters also the Wentzel-Kramers-Brillouin (WKB) formula used to extract

  16. Estimating collective dose in nuclear facilities, with emphasis on the design process

    International Nuclear Information System (INIS)

    Cohen, S.; Mann, B.

    1987-01-01

    The report presents a more accurate, systematic method than has been available previously for predicting worker doses which might be incurred during routine and non-routine work in radioactive areas. Besides assisting regulators with an analysis of the ''potential impact on radiological exposures of facility employees'' now required under the new backfit rule (10 CFR 50.109c), this predictive model will also help licensees conserve dollars as well as dose because it can be employed very early in the engineering design phase of a modification, when adjustments can still be made easily to change orders. Such early estimates make good business sense because they will facilitate planning, labor loading, costing, resource and equipment scheduling, and overall coordination of both single and repetitive projects. Also, with the support of corporate management, radiation protection coordinators can introduce the model into training programs to acquaint design engineers and others with dose calculation techniques. The importance assigned by nuclear industry senior management to the principle of ALARA and the reduction of collective worker dose is measured, in large part, by demonstrated efforts to integrate the control of radiation exposure fully into the overall planning function of nuclear facility management. That integration will be fostered through the use of this approach

  17. Nuclear Malaysia in the news 2013: Making headlines in nuclear technology

    International Nuclear Information System (INIS)

    2014-01-01

    Nuclear was a term that always misunderstands by public as a terrifying term. The nuclear activities around Malaysia was disseminated in newspaper and Malaysian Nuclear Agency as a responsible agency for nuclear for peace were collecting that news and compiled them to make the public aware the benefits of nuclear energy to develop our country. All the news about nuclear were collected using various type of newspaper published in Malaysia such as Utusan Malaysia, Berita Harian, Daily Express, News Straits Time, The Star, Borneo Post and others. This news was compiled according to their main topics such as energy, nuclear in agriculture, education and others. Each year one edition of this report will publish and disseminate it to the other libraries, government agencies, school and others to make the public aware the existence of nuclear activities around their countries.

  18. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Ukita, G.M. [Universidade de Santo Amaro, SP (Brazil). Faculdade de Psicologia

    2004-09-15

    The study of the odd {sup 99,101}Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in {sup 100,102,104}Ru. Angular distributions for the {sup 99,101}Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of J{pi} = 5=2{sup +}, 7=2{sup +} and 9=2{sup +}. Through the comparison of experimental and predicted cross section angular distributions, the values of ({delta}{sup L}{sub N}){sup 2} and of the ratio C = {delta}{sub L}{sup C} /{delta}{sub L}{sup N} were obtained. (author)

  19. An historical collection of papers on nuclear thermal propulsion

    Science.gov (United States)

    The present volume of historical papers on nuclear thermal propulsion (NTP) encompasses NTP technology development regarding solid-core NTP technology, advanced concepts from the early years of NTP research, and recent activities in the field. Specific issues addressed include NERVA rocket-engine technology, the development of nuclear rocket propulsion at Los Alamos, fuel-element development, reactor testing for the Rover program, and an overview of NTP concepts and research emphasizing two decades of NASA research. Also addressed are the development of the 'nuclear light bulb' closed-cycle gas core and a demonstration of a fissioning UF6 gas in an argon vortex. The recent developments reviewed include the application of NTP to NASA's Lunar Space Transportation System, the use of NTP for the Space Exploration Initiative, and the development of nuclear rocket engines in the former Soviet Union.

  20. Moving target feature phenomenology data collection at China Lake

    Science.gov (United States)

    Gross, David C.; Hill, Jeff; Schmitz, James L.

    2002-08-01

    This paper describes the DARPA Moving Target Feature Phenomenology (MTFP) data collection conducted at the China Lake Naval Weapons Center's Junction Ranch in July 2001. The collection featured both X-band and Ku-band radars positioned on top of Junction Ranch's Parrot Peak. The test included seven targets used in eleven configurations with vehicle motion consisting of circular, straight-line, and 90-degree turning motion. Data was collected at 10-degree and 17-degree depression angles. Key parameters in the collection were polarization, vehicle speed, and road roughness. The collection also included a canonical target positioned at Junction Ranch's tilt-deck turntable. The canonical target included rotating wheels (military truck tire and civilian pick-up truck tire) and a flat plate with variable positioned corner reflectors. The canonical target was also used to simulate a rotating antenna and a vibrating plate. The target vehicles were instrumented with ARDS pods for differential GPS and roll, pitch and yaw measurements. Target motion was also documented using a video camera slaved to the X-band radar antenna and by a video camera operated near the target site.

  1. Hadronic energy spectra from nuclear collisions: Effects from collective transverse flow and the phase transition to quark matter

    International Nuclear Information System (INIS)

    Heinz, U.

    1988-11-01

    I give an overview of the processes determining the shape of energy spectra of hadrons emitted in relativistic nuclear collisions, and discuss how one can extract from them information on the presence of collective transverse flow and on the transition to quark-gluon matter in such collisions. 6 refs., 3 figs

  2. French experience in transient data collection and fatigue monitoring of PWR's nuclear steam supply system

    International Nuclear Information System (INIS)

    Sabaton, M.; Morilhat, P.; Savoldelli, D.; Genette, P.

    1995-10-01

    Electricite de France (EDF), the french national electricity company, is operating 54 standardized pressurizer water reactors. This about 500 reactor-years experience in nuclear stations operation and maintenance area has allowed EDF to develop its own strategy for monitoring of age-related degradations of NPP systems and components relevant for plant safety and reliability. After more than fifteen years of experience in regulatory transient data collection and seven years of successful fatigue monitoring prototypes experimentation, EDF decided to design a new system called SYSFAC (acronym for SYsteme de Surveillance en FAtigue de la Chaudiere) devoted to transient logging and thermal fatigue monitoring of the reactor coolant pressure boundary. The system is fully automatic and directly connected to the on-site data acquisition network without any complementary instrumentation. A functional transient detection module and a mechanical transient detection module are in charge of the general transient data collection. A fatigue monitoring module is aimed towards a precise surveillance of five specific zones particularly sensible to thermal fatigue. After the first step of preliminary studies, the industrial phase of the SYSFAC project is currently going on, with hardware and software tests and implementation. The first SYSFAC system will be delivered to the pilot power plant by the beginning of 1996. The extension to all EDF's nuclear 900 MW is planned after one more year of feedback experience. (authors). 12 refs., 3 figs

  3. Transverse momentum in high-energy nuclear collisions: Collective expansion

    International Nuclear Information System (INIS)

    Wang, X.; Hwa, R.C.

    1987-01-01

    Hadron production in the central region in high-energy nuclear collisions is investigated. The hydrodynamical expansion of a locally thermalized system is studied for both the cases with and without phase transition. The case with phase transition is considered by using a sound-velocity function c/sub s/(T) parametrized to fit the energy density determined in a lattice gauge calculation. The effect of a transverse rarefaction wave is included in the calculation of the temperature profile of the expanding fluid. The transverse-momentum distribution of hadrons is calculated by collecting all the hadrons produced when the hadron gas is cooled down to a freeze-out temperature at different times in the expansion. Fluctuation in initial temperature and radius is allowed due to variation in impact parameter. On the basis of a study of the thermalization process in the parton model we impose a constraint on the initial temperature and the thermalization time, the simultaneous variation of both of which gives rise to a relationship between the average transverse momentum and rapidity density. We have found that there is no so-called ''plateau'' region in that relationship. The implication on the diagnostics of a quark-gluon plasma is discussed

  4. Contrast generation in the nuclear-spin tomography by pulsed ultrasound

    International Nuclear Information System (INIS)

    Oehms, Ole Benjamin

    2009-01-01

    In the framework of this thesis a combined method of ultrasound and nuclear-spin tomography is presented. Via ultrasound pulses by the sound-radiation force in liquids and tissue phantoms motions are generated, which depend on ther viscoelastic properties. This motions are made visible by a motion-sensitive tomograph sequence in the phase image of the tomograph in form of a phase change. The first measurements on simple phantoms and liquids are presented. [de

  5. Visual motion detection and habitat preference in Anolis lizards.

    Science.gov (United States)

    Steinberg, David S; Leal, Manuel

    2016-11-01

    The perception of visual stimuli has been a major area of inquiry in sensory ecology, and much of this work has focused on coloration. However, for visually oriented organisms, the process of visual motion detection is often equally crucial to survival and reproduction. Despite the importance of motion detection to many organisms' daily activities, the degree of interspecific variation in the perception of visual motion remains largely unexplored. Furthermore, the factors driving this potential variation (e.g., ecology or evolutionary history) along with the effects of such variation on behavior are unknown. We used a behavioral assay under laboratory conditions to quantify the visual motion detection systems of three species of Puerto Rican Anolis lizard that prefer distinct structural habitat types. We then compared our results to data previously collected for anoles from Cuba, Puerto Rico, and Central America. Our findings indicate that general visual motion detection parameters are similar across species, regardless of habitat preference or evolutionary history. We argue that these conserved sensory properties may drive the evolution of visual communication behavior in this clade.

  6. Seismic methodology in determining basis earthquake for nuclear installation

    International Nuclear Information System (INIS)

    Ameli Zamani, Sh.

    2008-01-01

    Design basis earthquake ground motions for nuclear installations should be determined to assure the design purpose of reactor safety: that reactors should be built and operated to pose no undue risk to public health and safety from earthquake and other hazards. Regarding the influence of seismic hazard to a site, large numbers of earthquake ground motions can be predicted considering possible variability among the source, path, and site parameters. However, seismic safety design using all predicted ground motions is practically impossible. In the determination of design basis earthquake ground motions it is therefore important to represent the influences of the large numbers of earthquake ground motions derived from the seismic ground motion prediction methods for the surrounding seismic sources. Viewing the relations between current design basis earthquake ground motion determination and modem earthquake ground motion estimation, a development of risk-informed design basis earthquake ground motion methodology is discussed for insight into the on going modernization of the Examination Guide for Seismic Design on NPP

  7. Local Dynamic Stability Assessment of Motion Impaired Elderly Using Electronic Textile Pants.

    Science.gov (United States)

    Liu, Jian; Lockhart, Thurmon E; Jones, Mark; Martin, Tom

    2008-10-01

    A clear association has been demonstrated between gait stability and falls in the elderly. Integration of wearable computing and human dynamic stability measures into home automation systems may help differentiate fall-prone individuals in a residential environment. The objective of the current study was to evaluate the capability of a pair of electronic textile (e-textile) pants system to assess local dynamic stability and to differentiate motion-impaired elderly from their healthy counterparts. A pair of e-textile pants comprised of numerous e-TAGs at locations corresponding to lower extremity joints was developed to collect acceleration, angular velocity and piezoelectric data. Four motion-impaired elderly together with nine healthy individuals (both young and old) participated in treadmill walking with a motion capture system simultaneously collecting kinematic data. Local dynamic stability, characterized by maximum Lyapunov exponent, was computed based on vertical acceleration and angular velocity at lower extremity joints for the measurements from both e-textile and motion capture systems. Results indicated that the motion-impaired elderly had significantly higher maximum Lyapunov exponents (computed from vertical acceleration data) than healthy individuals at the right ankle and hip joints. In addition, maximum Lyapunov exponents assessed by the motion capture system were found to be significantly higher than those assessed by the e-textile system. Despite the difference between these measurement techniques, attaching accelerometers at the ankle and hip joints was shown to be an effective sensor configuration. It was concluded that the e-textile pants system, via dynamic stability assessment, has the potential to identify motion-impaired elderly.

  8. Geophysical assessment of near-field ground motion and the implications for the design of nuclear installations

    International Nuclear Information System (INIS)

    Bernreuter, D.L.

    1977-01-01

    This paper gives an in-depth discussion on the various methodologies currently available to predict the near-field ground motion from an earthquake. The limitations of the various methods are discussed in some detail in light of recently available data. It is shown that, (at least for California earthquakes) for an earthquake with a given magnitude a wide variation in the peak ground motion can occur. The change in the spectral content of the ground motion is given as a function of earthquake magnitude and peak ground acceleration. It is shown that the large g values associated with small earthquakes are relatively unimportant in the design provided the structures have a modest amount of ductility. Data recently obtained from the Friuli earthquake are also examined. Although not all the geophysical data are currently available, the provisional conclusion is reached that the relation between the strong ground motion from this earthquake and its source parameters is the same as for the western United States

  9. Protoparvovirus Knocking at the Nuclear Door.

    Science.gov (United States)

    Mäntylä, Elina; Kann, Michael; Vihinen-Ranta, Maija

    2017-10-02

    Protoparvoviruses target the nucleus due to their dependence on the cellular reproduction machinery during the replication and expression of their single-stranded DNA genome. In recent years, our understanding of the multistep process of the capsid nuclear import has improved, and led to the discovery of unique viral nuclear entry strategies. Preceded by endosomal transport, endosomal escape and microtubule-mediated movement to the vicinity of the nuclear envelope, the protoparvoviruses interact with the nuclear pore complexes. The capsids are transported actively across the nuclear pore complexes using nuclear import receptors. The nuclear import is sometimes accompanied by structural changes in the nuclear envelope, and is completed by intranuclear disassembly of capsids and chromatinization of the viral genome. This review discusses the nuclear import strategies of protoparvoviruses and describes its dynamics comprising active and passive movement, and directed and diffusive motion of capsids in the molecularly crowded environment of the cell.

  10. 75 FR 11566 - Firstenergy Nuclear Operating Company, Firstenergy Nuclear Generation Corp., Ohio Edison Company...

    Science.gov (United States)

    2010-03-11

    ... deep drop and a fuel to fuel drop. The shallow drop postulates that the fuel assembly drops vertically... need for SUNSI, deadline for NRC staff to complete information processing and file motion for... Information AGENCY: Nuclear Regulatory Commission. ACTION: Order and notice of license amendment request...

  11. 76 FR 48908 - Agency Information Collection Activities: Proposed Collection; Comment Request

    Science.gov (United States)

    2011-08-09

    ...-mail addresses, school information/grades, employment information/histories, and works of writing... minimized, including the use of automated collection techniques or other forms of information technology... NUCLEAR REGULATORY COMMISSION [Docket No. NRC-2011-0160] Agency Information Collection Activities...

  12. The collection of symposium reports for people to understand nuclear power

    International Nuclear Information System (INIS)

    1988-07-01

    It deals with the symposium reports which gives people public information on nuclear power. It introduces the programs on public information and measures in France, Japan, Canada, Korea. It reports the presentations of the result which are the education programs for children and people about safety of nuclear power, nuclear power plant and environmental disruption, safety insurance of nuclear power and the present condition of operating nuclear power plant.

  13. Apsidal Motion Study of Close Binary System CW Cephei

    Directory of Open Access Journals (Sweden)

    Wonyong Han

    2015-12-01

    Full Text Available New observations for the times of minimum lights of a well-known apsidal motion star CW Cephei were made using a 0.6 m wide field telescope at Jincheon station of Chungbuk National University Observatory, Korea during the 2015 observational season. We determined new times of minimum lights from these observations and analyzed O-C diagrams together with collected times of minima to study both the apsidal motion and the Light Time Effect (LTE suggested in the system. The new periods of the apsidal motion and the LTE were calculated as 46.6 and 39.3 years, respectively, which were similar but improved accuracy than earlier ones investigated by Han et al. (2002, Erdem et al. (2004 and Wolf et al. (2006.

  14. Motion Picture and Television Research Libraries in the Los Angeles Area.

    Science.gov (United States)

    Dumaux, Sally

    1979-01-01

    Discusses the changes in the major motion picture research collections during the past 15 years and describes the contents of the five largest remaining ones: Twentieth Century-Fox Research Library, Metro-Goldwyn-Mayer Research Library, Burbank Public Library--Warner Research Collection, Universal City Studios Research Library, Walt Disney…

  15. Chaos near the Coulomb barrier. Nuclear molecules

    International Nuclear Information System (INIS)

    Strayer, M.R.

    1984-01-01

    The present work examines in detail the classical behavior of the α + 14 C and the 12 C + 12 C(O + ) collison at energies near the Coulomb barrier. The long-time motion of the compound nuclear system is identified in terms of its classical quasiperiodic and chaotic behavior. The consequences of this motion are discussed and interpreted in terms of the evolution of the system along a dynamical energy surface. 45 references

  16. Dynamic testing of nuclear power plant structures: an evaluation

    International Nuclear Information System (INIS)

    Weaver, H.J.

    1980-02-01

    Lawrence Livermore Laboratory (LLL) evaluated the applications of system identification techniques to the dynamic testing of nuclear power plant structures and subsystems. These experimental techniques involve exciting a structure and measuring, digitizing, and processing the time-history motions that result. The data can be compared to parameters calculated using finite element or other models of the test systems to validate the model and to verify the seismic analysis. This report summarizes work in three main areas: (1) analytical qualification of a set of computer programs developed at LLL to extract model parameters from the time histories; (2) examination of the feasibility of safely exciting nuclear power plant structures and accurately recording the resulting time-history motions; (3) study of how the model parameters that are extracted from the data be used best to evaluate structural integrity and analyze nuclear power plants

  17. Shielding calculations and collective dose estimations with the point-kernel-code VISIPLAN registered for the example of the project ZENT

    International Nuclear Information System (INIS)

    Boehlke, S.; Niegoth, H.

    2012-01-01

    In the nuclear power plant Leibstadt (KKL) during the next year large components will be dismantled and stored for final disposal within the interim storage facility ZENT at the NPP site. Before construction of ZENT appropriate estimations of the local dose rate inside and outside the building and the collective dose for the normal operation have to be performed. The shielding calculations are based on the properties of the stored components and radiation sources and on the concepts for working place requirements. The installation of control and monitoring areas will depend on these calculations. For the determination of the shielding potential of concrete walls and steel doors with the defined boundary conditions point-kernel codes like MICROSHIELd registered are used. Complex problems cannot be modeled with this code. Therefore the point-kernel code VISIPLAN registered was developed for the determination of the local dose distribution functions in 3D models. The possibility of motion sequence inputs allows an optimization of collective dose estimations for the operational phases of a nuclear facility.

  18. Deficient Biological Motion Perception in Schizophrenia: Results from a Motion Noise Paradigm

    Directory of Open Access Journals (Sweden)

    Jejoong eKim

    2013-07-01

    Full Text Available Background: Schizophrenia patients exhibit deficient processing of perceptual and cognitive information. However, it is not well understood how basic perceptual deficits contribute to higher level cognitive problems in this mental disorder. Perception of biological motion, a motion-based cognitive recognition task, relies on both basic visual motion processing and social cognitive processing, thus providing a useful paradigm to evaluate the potentially hierarchical relationship between these two levels of information processing. Methods: In this study, we designed a biological motion paradigm in which basic visual motion signals were manipulated systematically by incorporating different levels of motion noise. We measured the performances of schizophrenia patients (n=21 and healthy controls (n=22 in this biological motion perception task, as well as in coherent motion detection, theory of mind, and a widely used biological motion recognition task. Results: Schizophrenia patients performed the biological motion perception task with significantly lower accuracy than healthy controls when perceptual signals were moderately degraded by noise. A more substantial degradation of perceptual signals, through using additional noise, impaired biological motion perception in both groups. Performance levels on biological motion recognition, coherent motion detection and theory of mind tasks were also reduced in patients. Conclusion: The results from the motion-noise biological motion paradigm indicate that in the presence of visual motion noise, the processing of biological motion information in schizophrenia is deficient. Combined with the results of poor basic visual motion perception (coherent motion task and biological motion recognition, the association between basic motion signals and biological motion perception suggests a need to incorporate the improvement of visual motion perception in social cognitive remediation.

  19. Nuclear weapons headed for the trash

    International Nuclear Information System (INIS)

    Arkin, W.M.; Durrant, D.; Kristensen, H.

    1991-01-01

    Whether he intended it or not, Bush has taken steps that mean the beginning of the end for nuclear weapons. His proposals significantly reduce the numbers of nuclear weapons and the burdens associated with deploying and controlling them. And although he retains many of the options for continuing and regenerating the nuclear arsenal, he has exposed the fact that there are no longer any grand justifications or doctrinal needs for nuclear weapons - and that the nuclear machine is choking on its economic, political, environmental, and human contradictions. The initiatives fundamentally altered the nuclear stance of both nations. Yet, as momentous as the changes were, they were set in motion in an almost businesslike manner. Neither leader truly framed the moves as an end to the nuclear age. But they didn't need to. The steps they have taken practically guarantee it

  20. Near-Field Ground Motion Modal versus Wave Propagation Analysis

    Directory of Open Access Journals (Sweden)

    Artur Cichowicz

    2010-01-01

    Full Text Available The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.

  1. Feasibility study for adding a demand failure data collection system to the Nuclear Plant Reliability Data System. Final report

    International Nuclear Information System (INIS)

    Tashjian, B.M.; Logan, B.W.

    1983-07-01

    Southwest Research Institute (SwRI) is pleased to submit to Sandia National Laboratories this technical report as fulfillment of Task 5 of the proposal entitled A Feasibility Study for Adding a Duty Cycle Data Collection System to the Nuclear Plant Reliability Data System. The purpose of this report is to summarize the work as delineated in the proposal tasks and to recommend follow-on activities. Technical support for this work was provided by Duke Power Company (Duke), subcontractor to SwRI. The four tasks to be performed in conjunction with the Duty Cycle Data Collection Study (renamed in this report Demand Data Collection) were: define component population and measurable parameters; develop data collection and assessment methodologies; assess the impact on utilities; and assess the impact on NPRDS

  2. Video repairing under variable illumination using cyclic motions.

    Science.gov (United States)

    Jia, Jiaya; Tai, Yu-Wing; Wu, Tai-Pang; Tang, Chi-Keung

    2006-05-01

    This paper presents a complete system capable of synthesizing a large number of pixels that are missing due to occlusion or damage in an uncalibrated input video. These missing pixels may correspond to the static background or cyclic motions of the captured scene. Our system employs user-assisted video layer segmentation, while the main processing in video repair is fully automatic. The input video is first decomposed into the color and illumination videos. The necessary temporal consistency is maintained by tensor voting in the spatio-temporal domain. Missing colors and illumination of the background are synthesized by applying image repairing. Finally, the occluded motions are inferred by spatio-temporal alignment of collected samples at multiple scales. We experimented on our system with some difficult examples with variable illumination, where the capturing camera can be stationary or in motion.

  3. Recent progress in the microscopic description of small and large amplitude collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, D., E-mail: lacroix@ipno.in2p3.fr; Tanimura, Y. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, F-91406 Orsay Cedex (France); Ayik, S. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Scamps, G. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Simenel, C. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 2601 (Australia); Yilmaz, B. [Physics Department, Faculty of Sciences, Ankara University, 06100, Ankara (Turkey)

    2015-10-15

    Dynamical mean-field theory has recently attracted much interests to provide a unified framework for the description of many aspects of nuclear dynamics [1, 2, 3, 4, 5] (for recent reviews see [6, 7]). In particular, the inclusion of pairing correlation has opened new perspectives [8, 9, 10, 11, 12]. A summary of recent applications including giant resonances and transfer reactions will be made in this talk [13, 14, 15, 16]. While new progresses have been made with the use of sophisticated effective interactions and the development of symmetry unrestricted applications, mean-field dynamics suffer from the poor treatment of quantum fluctuations in collective space. As a consequence, these theories are successful in describing average properties of many different experimental observations but generally fail to account realistically for the width of experimental distribution. The increase of predictive power of dynamical mean-field theory is facing the difficulty of going beyond the independent particle or quasi-particle picture. Nevertheless, in the last decade, novel methods have been proposed to prepare the next generation of microscopic mean-field codes able to account for both average properties and fluctuations around the average. A review of recent progresses in this direction as well as recent applications to heavy-ion collisions will be given [17, 18].

  4. Collective motion and alignment of particles at high angular momentum. Study of transition nuclei 54 ≤Z ≤60

    International Nuclear Information System (INIS)

    El-Samman, H.

    1986-03-01

    A Multidetector system such as multiplicity filter, set-up for energy γ energy γ correlation measurements and 12 and 14 element modular sum-spectrometers has been built with hexagonal cross-section NaI (T1) detectors. This system is used in studies of continuum γ-ray spectra at high angular momentum to determine the collective J band (2) and effective J eff (2) dynamic moments of inertia in 54≤Z≤60 transitional nuclei. Comparisons between our measurements and calculations in a cranking Nilsson-Strutinsky model show that 128,130 Ba have a pure collective behaviour with pure prolate (γ =0 deg) deformation at high spin while 118,122 Xe are triaxial (γ = 33 deg) with moderate deformation (ε = 0.25). We demonstrate the existence of a secondary minimum at larger deformation (ε = 0.35) in the potential energy surfaces of 128,130 Ba. This minimum is associated with the alignment of h 9/2 and i 13/2 neutrons and produces a shape change in the bariums. The influence of the odd proton in the A = 120 region is also demonstrated by the shape change from triaxial to prolate we observed in 123 Cs at high frequency. Informations on deformation and particle alignement are obtained from measurements of J eff (2) in Xe, Ba, Ce and Nd isotopes. A direct comparison of J band (2) and J eff (2) shows that collective motion and particle alignment participate for about 50 % each in the total increase of angular momentum [fr

  5. Simulation study for the nuclear matter below the saturation density

    International Nuclear Information System (INIS)

    Kido, Toshihiko; Maruyama, Toshiki; Chiba, Satoshi; Niita, Koji

    1999-01-01

    The infinite nuclear matter that consists of numerous protons and neutrons is described by using periodic boundary conditions. The motion of each nucleon in the fundamental cell is decided by a Molecular Dynamics. The ground states or the excited states of the nuclear matter are simulated. (author)

  6. Nuclear Forensics' role in analyzing nuclear trafficking activities

    International Nuclear Information System (INIS)

    Hrnecek, E.; Mayer, K.; Schubert, A.; Wallenius, M.

    2010-01-01

    Nuclear forensics aims at identifying origin and intended use of nuclear material using information inherent to the nuclear material.The information gathered in nuclear forensics include isotopic composition, elemental composition, impurities and age of the material, macroscopic appearance and microstructure. The information so collected helps to solve criminal cases and put the individuals involved in nuclear trafficking in jails. The information also helps to improve safeguards and physical protection measures at place of theft or diversion to prevent future thefts or diversions.

  7. Quantized motion of trapped ions

    International Nuclear Information System (INIS)

    Steinbach, J.

    1999-01-01

    This thesis is concerned with a theoretical and numerical study of the preparation and coherent manipulation of quantum states in the external and internal degrees of freedom of trapped ions. In its first part, this thesis proposes and investigates schemes for generating several nonclassical states for the quantized vibrational motion of a trapped ion. Based on dark state preparation specific laser excitation configurations are presented which, given appropriately chosen initial states, realize the desired motional states in the steady-state, indicated by the cessation of the fluorescence emitted by the ion. The focus is on the SU(1,1) intelligent states in both their single- and two-mode realization, corresponding to one- and two-dimensional motion of the ion. The presented schemes are also studied numerically using a Monte-Carlo state-vector method. The second part of the thesis describes how two vibrational degrees of freedom of a single trapped ion can be coupled through the action of suitably chosen laser excitation. Concentrating on a two-dimensional ion trap with dissimilar vibrational frequencies a variety of quantized two-mode couplings are derived. The focus is on a linear coupling that takes excitations from one mode to another. It is demonstrated how this can result in a state rotation, in which it is possible to coherently transfer the motional state of the ion between orthogonal directions without prior knowledge of that motional state. The third part of this thesis presents a new efficient method for generating maximally entangled internal states of a collection of trapped ions. The method is deterministic and independent of the number of ions in the trap. As the essential element of the scheme a mechanism for the realization of a controlled NOT operation that can operate on multiple ions is proposed. The potential application of the scheme for high-precision frequency standards is explored. (author)

  8. Invariants of collective neutrino oscillations

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  9. Measurement of shoulder motion fraction and motion ratio

    International Nuclear Information System (INIS)

    Kang, Yeong Han

    2006-01-01

    This study was to understand about the measurement of shoulder motion fraction and motion ratio. We proposed the radiological criterior of glenohumeral and scapulothoracic movement ratio. We measured the motion fraction of the glenohumeral and scapulothoracic movement using CR (computed radiological system) of arm elevation at neutral, 90 degree, full elevation. Central ray was 15 .deg., 19 .deg., 22 .deg. to the cephald for the parallel scapular spine, and the tilting of torso was external oblique 40 .deg., 36 .deg., 22 .deg. for perpendicular to glenohumeral surface. Healthful donor of 100 was divided 5 groups by age (20, 30, 40, 50, 60). The angle of glenohumeral motion and scapulothoracic motion could be taken from gross arm angle and radiological arm angle. We acquired 3 images at neutral, 90 .deg. and full elevation position and measured radiographic angle of glenoheumeral, scapulothoracic movement respectively. While the arm elevation was 90 .deg., the shoulder motion fraction was 1.22 (M), 1.70 (W) in right arm and 1.31, 1.54 in left. In full elevation, Right arm fraction was 1.63, 1.84 and left was 1.57, 1.32. In right dominant arm (78%), 90 .deg. and Full motion fraction was 1.58, 1.43, in left (22%) 1.82, 1.94. In generation 20, 90 .deg. and Full motion fraction was 1.56, 1.52, 30' was 1.82, 1.43, 40' was 1.23, 1.16, 50' was 1.80, 1.28,60' was 1.24, 1.75. There was not significantly by gender, dominant arm and age. The criteria of motion fraction was useful reference for clinical diagnosis the shoulder instability

  10. Collective motion of macroscopic spheres floating on capillary ripples: Dynamic heterogeneity and dynamic criticality

    NARCIS (Netherlands)

    Sanli, Ceyda; Saitoh, K.; Luding, Stefan; van der Meer, Roger M.

    2014-01-01

    When a densely packed monolayer of macroscopic spheres floats on chaotic capillary Faraday waves, a coexistence of large scale convective motion and caging dynamics typical for glassy systems is observed. We subtract the convective mean flow using a coarse graining (homogenization) method and reveal

  11. Motion and properties of nuclear radio components in Seyfert galaxies seen with VLBI

    Science.gov (United States)

    Middelberg, E.; Roy, A. L.; Nagar, N. M.; Krichbaum, T. P.; Norris, R. P.; Wilson, A. S.; Falcke, H.; Colbert, E. J. M.; Witzel, A.; Fricke, K. J.

    2004-04-01

    We report EVN, MERLIN and VLBA observations at 18 cm, 6 cm and 3.6 cm of the Seyfert galaxies NGC 7674, NGC 5506, NGC 2110 and Mrk 1210 to study their structure and proper motions on pc scales and to add some constraints on the many possible causes of the radio-quietness of Seyferts. The component configurations in NGC 7674 and NGC 2110 are simple, linear structures, whereas the configurations in NGC 5506 and Mrk 1210 have multiple components with no clear axis of symmetry. We suggest that NGC 7674 is a low-luminosity compact symmetric object. Comparing the images at different epochs, we find a proper motion in NGC 7674 of (0.92±0.07) c between the two central components separated by 282 pc and, in NGC 5506, we find a 3 σ upper limit of 0.50 c for the components separated by 3.8 pc. Our results confirm and extend earlier work showing that the outward motion of radio components in Seyfert galaxies is non-relativistic on pc scales. We briefly discuss whether this non-relativistic motion is intrinsic to the jet-formation process or results from deceleration of an initially relativistic jet by interaction with the pc or sub-pc scale interstellar medium. We combined our sample with a list compiled from the literature of VLBI observations made of Seyfert galaxies, and found that most Seyfert nuclei have at least one flat-spectrum component on the VLBI scale, which was not seen in the spectral indices measured at arcsec resolution. We found also that the bimodal alignment of pc and kpc radio structures displayed by radio galaxies and quasars is not displayed by this sample of Seyferts, which shows a uniform distribution of misalignment between 0° and 90°. The frequent misalignment could result from jet precession or from deflection of the jet by interaction with gas in the interstellar medium.

  12. Collective phenomena in non-central nuclear collisions

    International Nuclear Information System (INIS)

    Voloshin, Sergei A.; Poskanzer, Arthur M.; Snellings, Raimond

    2008-01-01

    Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements

  13. Collective phenomena in non-central nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Voloshin, Sergei A.; Poskanzer, Arthur M.; Snellings, Raimond

    2008-10-20

    Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements.

  14. Markerless motion estimation for motion-compensated clinical brain imaging

    Science.gov (United States)

    Kyme, Andre Z.; Se, Stephen; Meikle, Steven R.; Fulton, Roger R.

    2018-05-01

    Motion-compensated brain imaging can dramatically reduce the artifacts and quantitative degradation associated with voluntary and involuntary subject head motion during positron emission tomography (PET), single photon emission computed tomography (SPECT) and computed tomography (CT). However, motion-compensated imaging protocols are not in widespread clinical use for these modalities. A key reason for this seems to be the lack of a practical motion tracking technology that allows for smooth and reliable integration of motion-compensated imaging protocols in the clinical setting. We seek to address this problem by investigating the feasibility of a highly versatile optical motion tracking method for PET, SPECT and CT geometries. The method requires no attached markers, relying exclusively on the detection and matching of distinctive facial features. We studied the accuracy of this method in 16 volunteers in a mock imaging scenario by comparing the estimated motion with an accurate marker-based method used in applications such as image guided surgery. A range of techniques to optimize performance of the method were also studied. Our results show that the markerless motion tracking method is highly accurate (brain imaging and holds good promise for a practical implementation in clinical PET, SPECT and CT systems.

  15. PET motion correction using PRESTO with ITK motion estimation

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Melissa [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Caldeira, Liliana; Scheins, Juergen [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany); Matela, Nuno [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Kops, Elena Rota; Shah, N Jon [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany)

    2014-07-29

    The Siemens BrainPET scanner is a hybrid MRI/PET system. PET images are prone to motion artefacts which degrade the image quality. Therefore, motion correction is essential. The library PRESTO converts motion-corrected LORs into highly accurate generic projection data [1], providing high-resolution PET images. ITK is an open-source software used for registering multidimensional data []. ITK provides motion estimation necessary to PRESTO.

  16. PET motion correction using PRESTO with ITK motion estimation

    International Nuclear Information System (INIS)

    Botelho, Melissa; Caldeira, Liliana; Scheins, Juergen; Matela, Nuno; Kops, Elena Rota; Shah, N Jon

    2014-01-01

    The Siemens BrainPET scanner is a hybrid MRI/PET system. PET images are prone to motion artefacts which degrade the image quality. Therefore, motion correction is essential. The library PRESTO converts motion-corrected LORs into highly accurate generic projection data [1], providing high-resolution PET images. ITK is an open-source software used for registering multidimensional data []. ITK provides motion estimation necessary to PRESTO.

  17. Sequential character of low-energy ternary and quaternary nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Bulychev, A. O. [Voronezh State University (Russian Federation)

    2016-09-15

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  18. Sequential character of low-energy ternary and quaternary nuclear fission

    International Nuclear Information System (INIS)

    Kadmensky, S. G.; Bulychev, A. O.

    2016-01-01

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  19. Guide on a national system for collecting, assessing and disseminating information on safety-related events in nuclear power plants

    International Nuclear Information System (INIS)

    1983-02-01

    There is a wide spectrum of safety significance in the events that can occur during nuclear power plant operations. It is important that lessons be learned from safety-related events (hereinafter referred to as unusual events) so as to improve the safety of nuclear power plants. Hence formal procedures should be established for this purpose. The purpose of this document is to provide guidance to Member States for establishing a system (hereinafter referred to as a national system) for collecting, storing, retrieving, assessing and disseminating information on unusual events in nuclear power plants. The guidance given is based on experience gained in the use of existing national and international systems. This guide covers a national system that is part of a programme to improve nuclear power plant safety using experience gained from operating plants both within and outside the country. Implementing the recommendations in this guide would render any national system compatible with other national systems and facilitate the participation in the IAEA System for Reporting Unusual Events with Safety Significance (hereinafter referred to as the IAEA Incident Reporting System, IAEA-IRS) for more widespread dissemination of lessons learned from nuclear power plant operation

  20. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List