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Sample records for nuclear structure gap

  1. 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.)

  2. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are ...

  3. Photonic band gap structure simulator

    Science.gov (United States)

    Chen, Chiping; Shapiro, Michael A.; Smirnova, Evgenya I.; Temkin, Richard J.; Sirigiri, Jagadishwar R.

    2006-10-03

    A system and method for designing photonic band gap structures. The system and method provide a user with the capability to produce a model of a two-dimensional array of conductors corresponding to a unit cell. The model involves a linear equation. Boundary conditions representative of conditions at the boundary of the unit cell are applied to a solution of the Helmholtz equation defined for the unit cell. The linear equation can be approximated by a Hermitian matrix. An eigenvalue of the Helmholtz equation is calculated. One computation approach involves calculating finite differences. The model can include a symmetry element, such as a center of inversion, a rotation axis, and a mirror plane. A graphical user interface is provided for the user's convenience. A display is provided to display to a user the calculated eigenvalue, corresponding to a photonic energy level in the Brilloin zone of the unit cell.

  4. Nuclear structure

    International Nuclear Information System (INIS)

    Diamond, R.M.; Stephens, F.S.; Deleplanque, M.A.; Draper, J.E.; Dines, E.L.; Davis, U.C.; Macchiavelli, A.O.

    1984-01-01

    Essentially the whole range of spins possible for many nuclei in the periodic table is available with the use of the 88-Inch cyclotron and SuperHILAC accelerators. Nuclei carry angular momentum principally in two ways: by aligning individual high j nucleons, and by a collective rotation of the nucleus as a whole. Deformed nuclei use both modes and it is the interplay between the single-particle and collective modes that leads to the great diversity of nuclear properties at high spin. Information about these states and their properties is obtained only by detailed γ-ray spectroscopy of their de-exciting transitions. But for the higher spins the population is usually spread over so many states that only average values of continuum properties can be determined. So one of the goals of present-day research is to push discrete spectroscopic studies to higher spin states, reducing the continuum region. To do this requires that the number of cascade pathways observed be reduced to a small enough number so that individual transitions can show. One way is to use a combination of sum-energy and multiplicity selection, that is, to define a smaller entry region. This is what the NaI crystal balls can do. Another technique is to set gates on the highest-lying discrete transitions observed and look at what is in coincidence (ahead) of them. Either method requires a drastic decrease in the number of cascades selected, so very good statistics are needed and this means many detectors as close as possible to the target. The authors use both techniques simultaneously. Current and planned experiments are described

  5. Next Generation Nuclear Plant GAP Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Sydney J [ORNL; Burchell, Timothy D [ORNL; Corwin, William R [ORNL; Fisher, Stephen Eugene [ORNL; Forsberg, Charles W. [Massachusetts Institute of Technology (MIT); Morris, Robert Noel [ORNL; Moses, David Lewis [ORNL

    2008-12-01

    As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.

  6. Maximizing band gaps in plate structures

    DEFF Research Database (Denmark)

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard

    2006-01-01

    Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...

  7. Phononic band gap structures as optimal designs

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole

    2003-01-01

    In this paper we use topology optimization to design phononic band gap structures. We consider 2D structures subjected to periodic loading and obtain the distribution of two materials with high contrast in material properties that gives the minimal vibrational response of the structure. Both in...

  8. Component nuclear containment structure

    International Nuclear Information System (INIS)

    Harstead, G.A.

    1979-01-01

    The invention described is intended for use primarily as a nuclear containment structure. Such structures are required to surround the nuclear steam supply system and to contain the effects of breaks in the nuclear steam supply system, or i.e. loss of coolant accidents. Nuclear containment structures are required to withstand internal pressure and temperatures which result from loss of coolant accidents, and to provide for radiation shielding during operation and during the loss of coolant accident, as well as to resist all other applied loads, such as earthquakes. The nuclear containment structure described herein is a composite nuclear containment structure, and is one which structurally combines two previous systems; namely, a steel vessel, and a lined concrete structure. The steel vessel provides strength to resist internal pressure and accommodate temperature increases, the lined concrete structure provides resistance to internal pressure by having a liner which will prevent leakage, and which is in contact with the concrete structure which provides the strength to resist the pressure

  9. Nuclear export controls - Closing the gaps

    International Nuclear Information System (INIS)

    Schmidt, Fritz W.

    2005-01-01

    Concerns over a nuclear 'black market' have focused international attention on the effectiveness of nuclear export controls. IAEA Director General Mohamed ElBaradei has stated that the emergence of a multinational illicit network demonstrated the inadequacy of the present export control system, that international cooperation on export controls lay on informal arrangements that were not only not binding but also limited in membership, and that export control information was not systematically shared with the IAEA. This criticism, often heard on the political level, does not really do justice to the work of export control groups. The emergence of a multinational illicit network does not necessarily prove failures in export control systems. Criminal activities, by definition, try to circumvent existing rules and regulations, or they exploit the absence of such rules on State level. To fight such individual cases is not so much a task of regular export control systems, whose function lies primarily in establishing standards and procedures for export controls on State level, but rather the task for intelligence services and their international cooperation. The basis of the export control regime is the Nuclear Non-Proliferation Treaty (NPT). Export controls can - and do - play an important role in fostering this universality goal by demanding the implementation of internationally agreed security standards in recipient countries before export licenses are granted. Drawn from the deliberations in the NPT conferences, the current standards to be demanded as conditions of supply are the following: Safeguards, Physical Protection, National export control provisions. According to the NPT system, export controls require IAEA verification in the recipient country. In addition, export controls enable States to provide information to the IAEA on exports and imports as required by the Additional Protocol. The 2005 NPT Review Conference will be an opportunity to review developments

  10. Exploring the gender gap on nuclear disarmament

    Energy Technology Data Exchange (ETDEWEB)

    Cherrin, S.J.

    1987-01-01

    This research explores the relationship between sex/gender factors and attitudes toward peace and militarism to determine whether more women than men favor non-military solutions to peace to examine the effect of gender identity on these attitudes. The investigation also looks at participation in a peace group, a military setting, child care, and the traditional homemaker role, to see what effect these activities might have on attitudes toward peace and militarism. In addition, the study explores whether there is a correlation between attitudes favorable to feminism and orientation toward war and peace issues. This study is guided by the sociological perspective which assumes that sex and gender differences, to the extent they exist, may be influenced by the social roles defined as appropriate for women and men. In this exploration there is not a sex gap on peace and military attitudes. A feminine gender identity does not have an effect on the direction of attitudes toward peace or militarism. However, an overall identification with masculine traits, plus believing oneself to be dominant, competitive and aggressive is correlated with a non-pacifist world view. Results of this study show that participation in a peace group is the best determinant of a pro-peace attitude, whereas participation in a military setting tends to be associated with a pro-military attitude.

  11. Thermo-Structural Response Caused by Structure Gap and Gap Design for Solid Rocket Motor Nozzles

    Directory of Open Access Journals (Sweden)

    Lin Sun

    2016-06-01

    Full Text Available The thermo-structural response of solid rocket motor nozzles is widely investigated in the design of modern rockets, and many factors related to the material properties have been considered. However, little work has been done to evaluate the effects of structure gaps on the generation of flame leaks. In this paper, a numerical simulation was performed by the finite element method to study the thermo-structural response of a typical nozzle with consideration of the structure gap. Initial boundary conditions for thermo-structural simulation were defined by a quasi-1D model, and then coupled simulations of different gap size matching modes were conducted. It was found that frictional interface treatment could efficiently reduce the stress level. Based on the defined flame leak criteria, gap size optimization was carried out, and the best gap matching mode was determined for designing the nozzle. Testing experiment indicated that the simulation results from the proposed method agreed well with the experimental results. It is believed that the simulation method is effective for investigating thermo-structural responses, as well as designing proper gaps for solid rocket motor nozzles.

  12. A model for gap conductance in nuclear fuel rods

    International Nuclear Information System (INIS)

    Loyalka, S.K.

    1982-01-01

    Computation of nuclear reactor fuel behavior under normal and off-normal conditions is influenced by gap conductance models. These models should provide accurate results for heat transfer for arbitrary gap widths and gas mixtures and should be based on considerations of the kinetic theory of gases. There has been considerable progress in the study of heat transfer in a simple gas for arbitrary Knudsen numbers (Kn = l/similar to d, where l is a meanfree-path and similar d is the gap width) in recent years. Using these recent results, a simple expression for heat transfer in a gas mixture (enclosed between parallel plates) for an arbitrary Knudsen number has been constructed, and a new model for gap conductance has been proposed. The latter reproduces the free molecular (small gap, Kn >> 1) and the jump limits (large gaps, Kn << 1) correctly, and it provides fairly accurate results for arbitrary gap widths. The new model is suitable for use in large fuel behavior computer programs

  13. Nuclear structure studies

    International Nuclear Information System (INIS)

    Walters, W.B.

    1992-01-01

    New results are reported for the decay and nuclear orientation of 114,116 I and 114 Sb as well as data for the structure of daughter nuclides 114,116 Te. New results for IBM-2 calculations for the structure of 126 Xe are also reported. A new approach to the problem of the underproduction of A = 120 nuclides in the astrophysical r-process is reported

  14. Nuclear structure theory

    International Nuclear Information System (INIS)

    French, J.B.; Koltun, D.S.

    1990-06-01

    This report summarizes progress during the past ten months in the following areas of research: pion double charge exchange reactions, including a theory of the isotensor term in the pion-nucleus optical potential, and a study of meson exchange contributions to the reactions at low energies. Nuclear inelastic scattering, using quark models to calculate nuclear structure functions, and to test for sensitivity to the substructure of nucleons in nuclei. Fluctuation-free statistical spectroscopy including the theory and computer programs for interacting-particle densities, spin cutoff factors, occupancies, strength sums, and other expectation values

  15. 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

  16. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    1994-01-01

    The collection of abstracts on selected topics in nuclear structure are given. Special attention pays to collective excitations and high-spin states of nuclei, giant resonance structure, nuclear reaction mechanisms and so on

  17. Steel structures for nuclear facilities

    International Nuclear Information System (INIS)

    1993-01-01

    In the guide the requirements concerning design and fabrication of steel structures for nuclear facilities and documents to be submitted to the Finnish Centre for Radiation and Nuclear Safety (STUK) are presented. Furthermore, regulations concerning inspection of steel structures during construction of nuclear facilities and during their operation are set forth

  18. Investigations of Nuclear Structure

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, Demetrios [Washington Univ., St. Louis, MO (United States); Reviol, W. [Washington Univ., St. Louis, MO (United States)

    2015-07-15

    The proposal addresses studies of nuclear structure at low-energies and development of instrumentation for that purpose. The structure studies deal with features of neutron-rich nuclei with unexplored shapes (football- or pear-shaped nuclei). The regions of interest are: neutron rich nuclei like 132-138Sn, or 48-54Ca, and the Zr, Mo, and Ru isotopes. The tools used can be grouped as follows: either Gammasphere or Gretina multi-gamma detector arrays and auxiliary detectors (Microball, Neutron Shell, and the newly completed Phoswich Wall).The neutron-rich nuclei are accessed by radioactive-beam binary reactions or by 252Cf spontaneous fission. The experiments with heavy radioactive beams aim at exciting the beam nuclei by pick-up or transfer a neutron or a proton from a light target like 13C, 9Be, 11B or 14N .For these binary-reaction studies the Phoswich Wall detector system is essential. It is based on four multi-anode photomultiplier tubes on which CsI and thin fast-timing plastic scintillators are attached. Their signals are digitized with a high density microchip system.

  19. Two-dimensional microwave band-gap structures of different ...

    Indian Academy of Sciences (India)

    Abstract. We report the use of low dielectric constant materials to form two- dimensional microwave band-gap structures for achieving high gap-to-midgap ratio. The variable parameters chosen are the lattice spacing and the geometric structure. The se- lected geometries are square and triangular and the materials chosen ...

  20. Diabatic orbitals in nuclear structure

    International Nuclear Information System (INIS)

    Bengtsson, Tord.

    1989-09-01

    The importance of wavefunctions in detailed nuclear structure calculations is emphasized. A scheme to enable studies of the development of wavefunctions as the hamiltonian gradually changes is presented. By using this scheme, nuclear structure properties can be calculated with great detail. (author)

  1. Nuclear Structure References (NSR) file

    International Nuclear Information System (INIS)

    Ewbank, W.B.

    1978-08-01

    The use of the Nuclear Structure References file by the Nuclear Data Project at ORNL is described. Much of the report concerns format information of interest only to those preparing input to the system or otherwise needing detailed knowledge of its internal structure. 17 figures

  2. Evaluated nuclear structure data file

    International Nuclear Information System (INIS)

    Tuli, J.K.

    1996-01-01

    The Evaluated Nuclear Structure Data File (ENSDF) contains the evaluated nuclear properties of all known nuclides, as derived both from nuclear reaction and radioactive decay measurements. All experimental data are evaluated to create the adopted properties for each nuclide. ENSDF, together with other numeric and bibliographic files, can be accessed on-line through the INTERNET or modem, and some of the databases are also available on the World Wide Web. The structure and the scope of ENSDF are presented along with the on-line access system of the National Nuclear Data Center at Brookhaven National Laboratory. (orig.)

  3. Structure and function of gap junction proteins: role of gap junction proteins in embryonic heart development.

    Science.gov (United States)

    Ahir, Bhavesh K; Pratten, Margaret K

    2014-01-01

    Intercellular (cell-to-cell) communication is a crucial and complex mechanism during embryonic heart development. In the cardiovascular system, the beating of the heart is a dynamic and key regulatory process, which is functionally regulated by the coordinated spread of electrical activity through heart muscle cells. Heart tissues are composed of individual cells, each bearing specialized cell surface membrane structures called gap junctions that permit the intercellular exchange of ions and low molecular weight molecules. Gap junction channels are essential in normal heart function and they assist in the mediated spread of electrical impulses that stimulate synchronized contraction (via an electrical syncytium) of cardiac tissues. This present review describes the current knowledge of gap junction biology. In the first part, we summarise some relevant biochemical and physiological properties of gap junction proteins, including their structure and function. In the second part, we review the current evidence demonstrating the role of gap junction proteins in embryonic development with particular reference to those involved in embryonic heart development. Genetics and transgenic animal studies of gap junction protein function in embryonic heart development are considered and the alteration/disruption of gap junction intercellular communication which may lead to abnormal heart development is also discussed.

  4. Relativistic approach to nuclear structure

    International Nuclear Information System (INIS)

    Nguyen Van Giai; Bouyssy, A.

    1987-03-01

    Some recent works related with relativistic models of nuclear structure are briefly reviewed. The Dirac-Hartree-Fock and Dirac-Brueckner-Hartree-Fock are recalled and illustrated by some examples. The problem of isoscalar current and magnetic moments of odd nuclei is discussed. The application of the relativistic model to the nuclear response function is examined

  5. Relativistic models of nuclear structure

    International Nuclear Information System (INIS)

    Gillet, V.; Kim, E.J.; Cauvin, M.; Kohmura, T.; Ohnaka, S.

    1991-01-01

    The introduction of the relativistic field formalism for the description of nuclear structure has improved our understanding of fundamental nuclear mechanisms such as saturation or many body forces. We discuss some of these progresses, both in the semi-classical mean field approximation and in a quantized meson field approach. (author)

  6. Nuclear Structure at the Limits

    International Nuclear Information System (INIS)

    Nazarewicz, W.

    1998-01-01

    One of the frontiers of todays nuclear science is the journey to the limits of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei

  7. Nuclear Structure at the Limits

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, Witold

    1997-12-31

    One of the frontiers of today`s nuclear science is the ``journey to the limits``: of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure at the limits are discussed from a theoretical perspective.

  8. Bi-directional evolutionary optimization for photonic band gap structures

    Science.gov (United States)

    Meng, Fei; Huang, Xiaodong; Jia, Baohua

    2015-12-01

    Toward an efficient and easy-implement optimization for photonic band gap structures, this paper extends the bi-directional evolutionary structural optimization (BESO) method for maximizing photonic band gaps. Photonic crystals are assumed to be periodically composed of two dielectric materials with the different permittivity. Based on the finite element analysis and sensitivity analysis, BESO starts from a simple initial design without any band gap and gradually re-distributes dielectric materials within the unit cell so that the resulting photonic crystal possesses a maximum band gap between two specified adjacent bands. Numerical examples demonstrated the proposed optimization algorithm can successfully obtain the band gaps from the first to the tenth band for both transverse magnetic and electric polarizations. Some optimized photonic crystals exhibit novel patterns markedly different from traditional designs of photonic crystals.

  9. Bi-directional evolutionary optimization for photonic band gap structures

    International Nuclear Information System (INIS)

    Meng, Fei; Huang, Xiaodong; Jia, Baohua

    2015-01-01

    Toward an efficient and easy-implement optimization for photonic band gap structures, this paper extends the bi-directional evolutionary structural optimization (BESO) method for maximizing photonic band gaps. Photonic crystals are assumed to be periodically composed of two dielectric materials with the different permittivity. Based on the finite element analysis and sensitivity analysis, BESO starts from a simple initial design without any band gap and gradually re-distributes dielectric materials within the unit cell so that the resulting photonic crystal possesses a maximum band gap between two specified adjacent bands. Numerical examples demonstrated the proposed optimization algorithm can successfully obtain the band gaps from the first to the tenth band for both transverse magnetic and electric polarizations. Some optimized photonic crystals exhibit novel patterns markedly different from traditional designs of photonic crystals.

  10. Optimum design of band-gap beam structures

    DEFF Research Database (Denmark)

    Olhoff, Niels; Niu, Bin; Cheng, Gengdong

    2012-01-01

    in the present paper that such an a priori assumption is not necessary since, in general, just the maximization of the gap between two consecutive natural frequencies leads to significant design periodicity. The aim of this paper is to maximize frequency gaps by shape optimization of transversely vibrating......The design of band-gap structures receives increasing attention for many applications in mitigation of undesirable vibration and noise emission levels. A band-gap structure usually consists of a periodic distribution of elastic materials or segments, where the propagation of waves is impeded...... or significantly suppressed for a range of external excitation frequencies. Maximization of the band-gap is therefore an obvious objective for optimum design. This problem is sometimes formulated by optimizing a parameterized design model which assumes multiple periodicity in the design. However, it is shown...

  11. Symmetries in nuclear structure

    CERN Document Server

    Allaart, K; Dieperink, A

    1983-01-01

    The 1982 summer school on nuclear physics, organized by the Nuclear Physics Division of the Netherlands' Physical Society, was the fifth in a series that started in 1963. The number of students attending has always been about one hundred, coming from about thirty countries. The theme of this year's school was symmetry in nuclear physics. This book covers the material presented by the enthusi­ astic speakers, who were invited to lecture on this subject. We think they have succeeded in presenting us with clear and thorough introductory talks at graduate or higher level. The time schedule of the school and the location allowed the participants to make many informal contacts during many social activities, ranging from billiards to surf board sailing. We hope and expect that the combination of a relaxed atmosphere during part of the time and hard work during most of the time, has furthered the interest in, and understanding of, nuclear physics. The organization of the summer school was made possible by substantia...

  12. Concrete structures for nuclear facilities

    International Nuclear Information System (INIS)

    1996-01-01

    The detailed requirements for the design and fabrication of the concrete structures for nuclear facilities and for the documents to be submitted to the Finnish Centre for Radiation and Nuclear Safety (STUK) are given in the guide. It also sets the requirements for the inspection of concrete structures during the construction and operation of facilities. The requirements of the guide primarily apply to new construction. As regards the repair and modification of nuclear facilities built before its publication, the guide is followed to the extent appropriate. The regulatory activities of the Finnish Centre for Radiation and Nuclear Safety during a nuclear facility's licence application review and during the construction and operation of the facility are summarised in the guide YVL 1.1

  13. Nuclear reactions as structure probes

    International Nuclear Information System (INIS)

    Fernandez, Bernard; Cugnon, Joseph; Roussel-Chomaz, Patricia; Sparenberg, Jean-Marc; Oliveira Santos, Francois de; Bauge, Eric; Poves, Alfredo; Keeley, Nicholas; Simenel, Cedric; Avez, Benoit; Lacroix, Denis; Baye, Daniel; Cortina-Gil, Dolores; Pons, Alexandre

    2007-09-01

    This publication gathers courses which aim at giving a view on new experiments which are performed by using radioactive beams, notably low intensity beams, in different accelerators, and allow the structure of very exotic nuclei to be characterized. Experimental as well as theoretical aspects are thus addressed. The contributions propose: a brief history of nuclear reactions and of instruments used to study them from the discovery of nucleus to the DWBA (Distorted Wave Born Approximation); an overview of nuclear reactions; experimental techniques; the theory of collisions at low energy; resonant elastic scattering, inelastic scattering and astrophysical reactions; to probe nuclear structure with nucleons; shell model and spectroscopic factors; analysis of transfer reactions and determination of spectroscopic factors; microscopic approaches of nuclear dynamics; theoretical aspects of dissociation reactions; experimental aspects of knockout reactions; research in oenology with the chemical characterisation of defective ageing of dry white wines

  14. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Faessler, A.

    1990-01-01

    Today's dream of nuclear structure physics is to calculate the properties of nuclei starting from Quantum-Chromodynamics (QCD). However, we are definitely not able to do that today and may be even in the future one would wish only to show in principle that this is possible. It probably will never be a daily approach to study excitation energies, transitions probabilities and other properties of nuclei. This paper discusses the possibility of coming from the shore of QCD to the other side of the river, to nuclear structure, not in one great arch buy like medieval bridges in several arches grounded each solidly on pillars going down to the river floor and by that connecting theory with the solid ground of experiments. The first arch is meant to connect QCD and the nucleon-nucleon phase shifts with the help to the nucleon-nucleon phase shifts with the experimentally fitted effective interactions for the final model spaces used in nuclear structure calculations. This is at the moment still by far the weakest arch although a large amount of work and ideas have been invested since about the middle of the 60's to derive a theory of effective interactions and to establish the connection of the effective interaction fitted to nuclear structure data with the bare interaction between nucleons in the vacuum. The last arch is connecting the effective nucleon-nucleon interaction with nuclear structure properties

  15. Proximity effect gaps in S/N/FI structures

    NARCIS (Netherlands)

    Huertas-Hernando, D.; Nazarov, Y.V.

    2005-01-01

    We study the proximity effect in hybrid structures consisting of superconductor and ferromagnetic insulator separated by a normal diffusive metal (S/N/FI structures). These stuctures were proposed to realize the absolute spin-valve effect. We pay special attention to the gaps in the density of

  16. Three-dimensional photonic band gaps in woven structures

    CERN Document Server

    Tsai Ya Chih; Pendry, J B

    1998-01-01

    In this paper, we studied the photonic properties of dielectric fibres woven into three-dimensional (3D) structures. Such fibres can be fabricated on the micrometre scale, and hence the gaps are in the far-infrared to the infrared regime. The vector-wave transfer matrix method is applied to evaluate the photonic band structures. We have also employed the constant-frequency dispersion surface scheme to investigate the development of a full band gap. Such a 3D absolute gap is observed in a rectangular lattice, but at a fairly large dielectric constant for the fibres. Ways to improve on this have been suggested. Our study indicates that woven structures are promising materials for realizing the 3D photonic insulator in the infrared regime. (author)

  17. Nuclear Structure at the Limits

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W.

    1998-01-12

    One of the frontiers of today�s nuclear science is the �journey to the limits� of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  18. Nuclear structure of Trypanosoma cruzi.

    Science.gov (United States)

    Schenkman, Sergio; Pascoalino, Bruno dos Santos; Nardelli, Sheila C

    2011-01-01

    The presence of nucleus in living organisms characterizes the Eukaryote domain. The nucleus compartmentalizes the genetic material surrounded by a double membrane called nuclear envelope. The nucleus has been observed since the advent of the light microscope, and sub-compartments such as nucleoli, diverse nuclear bodies and condensed chromosomes have been later recognized, being part of highly organized and dynamic structure. The significance and function of such organization has increased with the understanding of transcription, replication, DNA repair, recombination processes. It is now recognized as consequence of adding complexity and regulation in more complex eukaryotic cells. Here we provide a description of the actual stage of knowledge of the nuclear structure of Trypanosoma cruzi. As an early divergent eukaryote, it presents unique and/or reduced events of DNA replication, transcription and repair as well as RNA processing and transport to the cytosol. Nevertheless, it shows peculiar structure changes accordingly to the cell cycle and stage of differentiation. T. cruzi proliferates only as epimastigote and amastigote stages, and when these forms differentiate in trypomastigote forms, their cell cycle is arrested. This arrested stage is capable of invading mammalian cells and of surviving harsh conditions, such as the gut of the insect vector and mammalian macrophages. Transcription and replication decrease during transformation in trypomastigotes implicating large alterations in the nuclear structure. Recent evidences also suggest that T. cruzi nucleus respond to oxidative and nutritional stresses. Due to the phylogenetic proximity with other well-known trypanosomes, such as Trypanosoma brucei and Leishmania major, they are expected to have similar nuclear organization, although differences are noticed due to distinct life cycles, cellular organizations and the specific adaptations for surviving in different host environments. Therefore, the general

  19. The gender gap in reactions to nuclear accidents

    International Nuclear Information System (INIS)

    Wernette, D.R.

    1992-01-01

    Studies have shown that women are less in favor of nuclear power than are men. These differences have been explained by observed gender differences in values, levels of knowledge about nuclear energy, and perceptions of risks and benefits of advanced technology. This study employs data from three national surveys taken in the United States after the Three Mile Island (TMI) and Chernobyl events to identify the extent and nature of gender differences in views toward nuclear energy

  20. Laser measurements and nuclear structure

    International Nuclear Information System (INIS)

    Leander, G.A.

    1982-01-01

    The nuclear states amenable to laser studies are reviewed with respect to their structure. Systematic predictions are made, e.g., for magnetic moments of parity-mixed intrinsic orbitals in the Ac isotopes and for the shape of the known high-spin isomers in the Pb region

  1. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Stachura, Z.

    1984-09-01

    19. winter school in Zakopane was devoted to selected topics in nuclear structure such as: production of spin resonances, heavy ions reactions and their applications to the investigation of high spin states, octupole deformations, excited states and production of new elements etc. The experimental data are ofen compared with theoretical predictions. Report contains 28 papers. (M.F.W.)

  2. Underwater nuclear power plant structure

    International Nuclear Information System (INIS)

    Severs, S.; Toll, H.V.

    1982-01-01

    A structure for an underwater nuclear power generating plant comprising a triangular platform formed of tubular leg and truss members upon which are attached one or more large spherical pressure vessels and one or more small cylindrical auxiliary pressure vessels. (author)

  3. Chinese imperative: nuclear energy to bridge geographic and economic gaps

    International Nuclear Information System (INIS)

    Tson'yu, T.

    1995-01-01

    Strategic aims and macroeconomical indices on nuclear power engineering are briefly considered. Forecasts on growth of indices for NPP electrical power production are presented. The social-geographical causes and specificity of China stimulating the broad-scale development of nuclear power engineering in China are emphasized. 2 figs.; 1 tab

  4. Diversifying the composition and structure of managed late-successional forests with harvest gaps: What is the optimal gap size?

    Science.gov (United States)

    Christel C. Kern; Anthony W. D’Amato; Terry F. Strong

    2013-01-01

    Managing forests for resilience is crucial in the face of uncertain future environmental conditions. Because harvest gap size alters the species diversity and vertical and horizontal structural heterogeneity, there may be an optimum range of gap sizes for conferring resilience to environmental uncertainty. We examined the impacts of different harvest gap sizes on...

  5. Design for maximum band-gaps in beam structures

    DEFF Research Database (Denmark)

    Olhoff, Niels; Niu, Bin; Cheng, Gengdong

    2012-01-01

    This paper aims to extend earlier optimum design results for transversely vibrating Bernoulli-Euler beams by determining new optimum band-gap beam structures for (i) different combinations of classical boundary conditions, (ii) much larger values of the orders n and n-1 of adjacent upper and lowe...

  6. Time to increase momentum in bridging the nuclear skills gap

    International Nuclear Information System (INIS)

    Shepherd, John

    2014-01-01

    A international conference hosted by the International Atomic Energy Agency (IAEA) in May 2014 highlighted the difficult balancing act that countries have in making sure that a pool of talent continues to be available to the nuclear sector into the future. The International Conference on Human Resource Development for Nuclear Power Programmes noted the huge task of maintaining a skilled workforce with the ability to cover nuclear in its widest sense: everything from fuel manufacturing, nuclear power plant operations, decommissioning, waste management and of course nurturing those who may become future regulators or captains of industry. The conference also correctly identified the different requirements of countries depending on their individual circumstances. There can certainly be no delay in this task. Even if no new nuclear power plants were to be built again - which is certainly not the case - highly-skilled individuals would still be required to manage existing plants, work in decommissioning, waste management and so on. The nuclear industry should continue and expand its support for academies, training establishments and other such institutions with the goal of training the next generation of nuclear professionals. At the same time, knowledge transfer programmes should be stepped up, so that professionals who are approaching retirement can pass on their invaluable expertise to those who will follow them. (orig.)

  7. Problems of structural mechanics in nuclear design

    International Nuclear Information System (INIS)

    Patwardhan, V.M.; Kakodkar, Anil

    1975-01-01

    A very careful and detailed stress analysis of nuclear presure vessels and components is essential for ensuring the safety and integrity of nuclear power plants. The nuclear designer, therefore, relies heavily on structural mechanics for application of the most advanced stress analysis techniques to practical design problems. The paper reviews the inter-relation between structural mechanics and nuclear design and discusses a few of the specific structural mechanics problems faced by the nuclear designers in the Department of Atomic Energy, India. (author)

  8. Nuclear structure with coherent states

    CERN Document Server

    Raduta, Apolodor Aristotel

    2015-01-01

    This book covers the essential features of a large variety of nuclear structure properties, both collective and microscopic in nature. Most of results are given in an analytical form thus giving deep insight into the relevant phenomena. Using coherent states as variational states, which allows a description in the classical phase space, or provides the generating function for a boson basis, is an efficient tool to account, in a realistic fashion, for many complex properties. A detailed comparison with all existing nuclear structure models provides readers with a proper framework and, at the same time, demonstrates the prospects for new developments. The topics addressed are very much of current concern in the field. The book will appeal to practicing researchers and, due to its self-contained account, can also be successfully read and used by new graduate students.

  9. Chinese imperative: nuclear energy to bridge geographic and economic gaps

    International Nuclear Information System (INIS)

    Zongyu, T.

    1994-01-01

    Encouraged by successful operation of its first three nuclear units -Quinshan-1 (own design) and Daya Bay-1 and -2 (Framatome) - China is rapidly preparing to expand both sites. The immediate need is to overcome the shortage of electricity on the East coast. Medium to long term, the need is to ensure power for economic growth throughout China. (author) 2 figs., 1 tab

  10. Closing the gap between theory and practice in Nuclear Medicine

    International Nuclear Information System (INIS)

    Adams, E.J.; Poulos, A.

    2002-01-01

    Aim: The ultimate goal for any clinical teaching program is to have students who demonstrate clinical competence. The Nuclear Medicine Technologist like any health professional should graduate from their course: attaining a defined standard of core knowledge; demonstrating appropriate behaviour for the workplace; and, achieving a predetermined level of clinical skill. In the University of Sydney Nuclear Medicine course, revisions were made to the Clinical Education assessment tools to create a more incremental approach and define competencies that required a higher level of achievement. Nuclear Medicine theory delivery was changed to create a more contextual environment where the student was better prepared for the workplace. The aim of this study is firstly to analyse the relationship between assessment of contextual theory and assessment of clinical practice. A secondary aim is to investigate any relationship between individual clinical assessment tools. Clinical assessment tools include: clinical competencies; observed clinical skills examinations (OSCE); clinical and university supervisor assessments; and assignments. Nuclear Medicine theory assessment tools include: problem oriented teamwork presentations; assignment; and written examination. Method: Correlation of the students' overall marks in the subjects' Nuclear Medicine theory and Clinical Education in the years 2000 and 2001 was undertaken using SPSS. Correlation of the students' scores in the individual clinical assessment tools: Clinical Supervisor to University supervisor; Clinical Supervisor to OSCE; and University Supervisor to OSCE, was completed for the years 2000 and 2001. Results: A statistically significant correlation was found for the students' marks in Nuclear Medicine theory and Clinical Education for the same year. The University and Clinical Supervisors' results significantly correlated for all years. Correlation between the individual assessment tools used in Clinical Education was not

  11. ENSDF: a nuclear structure data bank for nuclear physicists

    International Nuclear Information System (INIS)

    Blachot, J.

    1987-02-01

    Data Banks have tremendously grown these last years. All the nuclear Structure information are now in the ENSDF. This file is used for the Nuclear Data Sheets publication. The part which contains only Adopted Data could be used as a Data Bank for Nuclear Physicists. Examples of retrevial are given [fr

  12. Statistical aspects of nuclear structure

    International Nuclear Information System (INIS)

    Parikh, J.C.

    1977-01-01

    The statistical properties of energy levels and a statistical approach to transition strengths are discussed in relation to nuclear structure studies at high excitation energies. It is shown that the calculations can be extended to the ground state domain also. The discussion is based on the study of random matrix theory of level density and level spacings, using the Gaussian Orthogonal Ensemble (GOE) concept. The short range and long range correlations are also studied statistically. The polynomial expansion method is used to obtain excitation strengths. (A.K.)

  13. Band gaps in grid structure with periodic local resonator subsystems

    Science.gov (United States)

    Zhou, Xiaoqin; Wang, Jun; Wang, Rongqi; Lin, Jieqiong

    2017-09-01

    The grid structure is widely used in architectural and mechanical field for its high strength and saving material. This paper will present a study on an acoustic metamaterial beam (AMB) based on the normal square grid structure with local resonators owning both flexible band gaps and high static stiffness, which have high application potential in vibration control. Firstly, the AMB with variable cross-section frame is analytically modeled by the beam-spring-mass model that is provided by using the extended Hamilton’s principle and Bloch’s theorem. The above model is used for computing the dispersion relation of the designed AMB in terms of the design parameters, and the influences of relevant parameters on band gaps are discussed. Then a two-dimensional finite element model of the AMB is built and analyzed in COMSOL Multiphysics, both the dispersion properties of unit cell and the wave attenuation in a finite AMB have fine agreement with the derived model. The effects of design parameters of the two-dimensional model in band gaps are further examined, and the obtained results can well verify the analytical model. Finally, the wave attenuation performances in three-dimensional AMBs with equal and unequal thickness are presented and discussed.

  14. Photon-assisted Andreev transport and sub-gap structures

    DEFF Research Database (Denmark)

    Wildt, M; Kutchinsky, Jonatan; Taboryski, Rafael Jozef

    2000-01-01

    by multiple Andreev reflection processes we observe microwave induced satellites, shifted in voltage by multiples of hf/en, where hf is the photon energy and n is the number of quasi-particle traversals as determined by the Andreev processes. The observed behavior is the analogue of the so-called photon......We report new measurements of microwave-induced perturbations of the sub-harmonic energy gap structures in the current-voltage characteristics of superconductor-semiconductor-superconductor junctions. Around the sub-gap bias voltages associated with the enhanced quasi-particle transfer mediated......-assisted tunneling but here associated with the multiple Andreev reflections. (C) 2000 Elsevier Science B.V. All rights reserved....

  15. Optical processes in different types of photonic band gap structures

    Science.gov (United States)

    Wang, Zhiguo; Gao, Mengqin; Ullah, Zakir; Chen, Haixia; Zhang, Dan; Zhang, Yiqi; Zhang, Yanpeng

    2015-06-01

    For the first time, we investigate the photonic band gap (PBG) structure in the static and moving electromagnetically induced grating (EIG) through scanning the frequency detunings of the probe field, dressing field and coupling field. Especially, the suppression and enhancement of the four wave mixing band gap signal (FWM BGS) and the probe transmission signal (PTS) can be observed when we scan the dressing field frequency detuning in the FWM BGS system. It is worth noting that the PBG structure and FWM BGS appear at the right of the electromagnetically induced transparency (EIT) position in the case of scanning the frequency detuning of the coupling field in the FWM BGS system, while the PBG structure and FWM BGS appears at the left of the EIT position on the condition of scanning the probe field frequency detuning. Moreover, in the moving PBG structure, we can obtain the nonreciprocity of FWM BGS. Furthermore, we can modulate the intensity, width, location of the FWM BGS and PTS through changing the frequency detunings and intensities of the probe field, dressing field and coupling field, sample length and the frequency difference of coupling fields in EIG. Such scheme could have potential applications in optical diodes, amplifiers and quantum information processing.

  16. Selected topic in nuclear structure. V. 1

    International Nuclear Information System (INIS)

    Broda, R.; Stachura, Z.; Styczen, J.

    1985-01-01

    A report of recent experiments performed in different laboratories and a review of fundamental problems of nuclear physics connected with study of nuclear structure, that had just been solved are presented. The proceedings contain 33 articles. (M.F.-W.)

  17. Broyden's method in nuclear structure calculations

    International Nuclear Information System (INIS)

    Baran, Andrzej; Bulgac, Aurel; Forbes, Michael McNeil; Hagen, Gaute; Nazarewicz, Witold; Schunck, Nicolas; Stoitsov, Mario V.

    2008-01-01

    Broyden's method, widely used in quantum chemistry electronic-structure calculations for the numerical solution of nonlinear equations in many variables, is applied in the context of the nuclear many-body problem. Examples include the unitary gas problem, the nuclear density functional theory with Skyrme functionals, and the nuclear coupled-cluster theory. The stability of the method, its ease of use, and its rapid convergence rates make Broyden's method a tool of choice for large-scale nuclear structure calculations

  18. Heat Transport as a Probe of Superconducting Gap Structure

    International Nuclear Information System (INIS)

    Petrovic, C.; Shakeripour, H.; Taillefer, L.

    2009-01-01

    The structure of the superconducting gap provides important clues on the symmetry of the order parameter and the pairing mechanism. The presence of nodes in the gap function imposed by symmetry implies an unconventional order parameter, other than s-wave. Here we show how measurements of the thermal conductivity at very low temperature can be used to determine whether such nodes are present in a particular superconductor, and shed light on their nature and location. We focus on the residual linear term at T → 0. A finite value in zero magnetic field is strong evidence for symmetry-imposed nodes, and the dependence on impurity scattering can distinguish between a line of nodes or point nodes. Application of a magnetic field probes the low-energy quasiparticle excitations, whether associated with nodes or with a small value of the gap on some part of the Fermi surface, as in a multi-band superconductor. We frame our discussion around archetypal materials: Nb for s-wave, Tl 2 Ba 2 CuO 6+δ for d-wave, Sr 2 RuO 4 for p-wave, and NbSe 2 for multi-band superconductivity. In that framework, we discuss three heavy-fermion superconductors: CeIrIn 5 , CeCoIn 5 and UPt 3 .

  19. Nano structures of amorphous silicon: localization and energy gap

    Directory of Open Access Journals (Sweden)

    Z Nourbakhsh

    2013-10-01

    Full Text Available Renewable energy research has created a push for new materials; one of the most attractive material in this field is quantum confined hybrid silicon nano-structures (nc-Si:H embedded in hydrogenated amorphous silicon (a-Si:H. The essential step for this investigation is studying a-Si and its ability to produce quantum confinement (QC in nc-Si: H. Increasing the gap of a-Si system causes solar cell efficiency to increase. By computational calculations based on Density Functional Theory (DFT, we calculated a special localization factor, [G Allan et al., Phys. Rev. B 57 (1997 6933.], for the states close to HOMO and LUMO in a-Si, and found most weak-bond Si atoms. By removing these silicon atoms and passivating the system with hydrogen, we were able to increase the gap in the a-Si system. As more than 8% hydrogenate was not experimentally available, we removed about 2% of the most localized Si atoms in the almost tetrahedral a-Si system. After removing localized Si atoms in the system with 1000 Si atoms, and adding 8% H, the gap increased about 0.24 eV. Variation of the gap as a function of hydrogen percentage was in good agreement with the Tight –Binding results, but about 2 times more than its experimental value. This might come from the fact that in the experimental conditions, it does not have the chance to remove the most localized states. However, by improving the experimental conditions and technology, this value can be improved.

  20. Subharmonic energy-gap structure in superconducting weak links

    DEFF Research Database (Denmark)

    Flensberg, K.; Hansen, Jørn Bindslev; Octavio, M.

    1988-01-01

    We present corrected calculations of the subharmonic energy-gap structure using the model of Octavio, Tinkham, Blonder, and Klapwijk, which includes the effect of normal scattering in the weak link. We show that while the overall predictions of this model do not change qualitatively, the details...... of the predicted curves are different and in better agreement with experiment. We also present calculation of the current-voltage characteristics and of the excess currents for T=0, as the normal scattering parameter Z is varied. We also show how the calculation can be shortened using symmetry arguments...

  1. The Cellular Distribution of RanGAP1 Is Regulated by CRM1-Mediated Nuclear Export in Mammalian Cells.

    Directory of Open Access Journals (Sweden)

    Keith Cha

    Full Text Available The Ran GTPase activating protein RanGAP1 plays an essential role in nuclear transport by stimulating RanGTP hydrolysis in the cytoplasmic compartment. In mammalian cells, unmodified RanGAP1 is predominantly cytoplasmic, whereas modification by small ubiquitin-related modifier protein (SUMO targets RanGAP1 to the cytoplasmic filaments of nuclear pore complex (NPC. Although RanGAP1 contains nine putative nuclear export signals and a nuclear localization signal, little is known if RanGAP1 shuttles between the nuclear and cytoplasmic compartments and how its primary localization in the cytoplasm and at the NPC is regulated. Here we show that inhibition of CRM1-mediated nuclear export using RNAi-knockdown of CRM1 and inactivation of CRM1 by leptomycin B (LMB results in nuclear accumulation of RanGAP1. LMB treatment induced a more robust redistribution of RanGAP1 from the cytoplasm to the nucleoplasm compared to CRM1 RNAi and also uniquely triggered a decrease or loss of RanGAP1 localization at the NPC, suggesting that LMB treatment is more effective in inhibiting CRM1-mediated nuclear export of RanGAP1. Our time-course analysis of LMB treatment reveals that the NPC-associated RanGAP1 is much more slowly redistributed to the nucleoplasm than the cytoplasmic RanGAP1. Furthermore, LMB-induced nuclear accumulation of RanGAP1 is positively correlated with an increase in levels of SUMO-modified RanGAP1, suggesting that SUMOylation of RanGAP1 may mainly take place in the nucleoplasm. Lastly, we demonstrate that the nuclear localization signal at the C-terminus of RanGAP1 is required for its nuclear accumulation in cells treated with LMB. Taken together, our results elucidate that RanGAP1 is actively transported between the nuclear and cytoplasmic compartments, and that the cytoplasmic and NPC localization of RanGAP1 is dependent on CRM1-mediated nuclear export.

  2. Magnetic field effects on charge structure factors of gapped graphene structure

    Science.gov (United States)

    Rezania, Hamed; Tawoose, Nasrin

    2018-02-01

    We present the behaviors of dynamical and static charge susceptibilities of undoped gapped graphene using the Green's function approach in the context of tight binding model Hamiltonian. Specially, the effects of magnetic field on the plasmon modes of gapped graphene structure are investigated via calculating correlation function of charge density operators. Our results show the increase of magnetic field leads to disappear high frequency plasmon mode for gapped case. We also show that low frequency plasmon mode has not affected by increase of magnetic field and chemical potential. Finally the temperature dependence of static charge structure factor of gapp graphene structure is studied. The effects of both magnetic field and gap parameter on the static structure factor are discusses in details.

  3. Present state of the perception gap of nuclear energy between Japanese nuclear energy supplying region and an energy consuming region

    International Nuclear Information System (INIS)

    Ohnishi, Teruaki

    2002-01-01

    Public opinion surveys have been carried out since 1998 on what phase and on what extent of the perception of nuclear energy differs between Japanese dwelling in energy supplying region and an energy-consuming region. Southern Fukui rural district where 15 nuclear reactors are now installed and Osaka urban region of about 100 km apart from Fukui were selected as the respective targets for the energy supplying and consuming regions. Analyses of the data of about 3000 samples have revealed the followings. (1) The public in the nuclear energy supplying region are very friendly to nuclear energy so that only about 20 and 39 of the public are resistive to the general promotion of nuclear energy in Japan and to the construction of another nuclear reactor in their dwelling region, respectively. (2) On the other hand, in the energy-consuming region those respective fractions are 41 and 70 implying strong resistance to nuclear energy in the urban region. (3) Both the degree of interest in and the degree of knowledge on nuclear energy are very low, whereas the extent of fear to nuclear is high for the urban public. (4) Not only the fraction of the public who are satisfied with their present life, but the public fraction who is eagerly support the thought of return-to-nature are very high in the urban region. (5) On the other hand, in the energy supplying region, many peoples eagerly want their life to become more convenient than it is now, and 6) all those trends (I)-(5) are revealed more pronouncedly in the woman than the man. The perception gap of nuclear energy thus became clear between Japanese dwelling in rural and urban regions. On the basis of this knowledge, discussions on the nature of the so-called NIMBY will be made from the socio-psychological viewpoint and propositions will also be made on the methods to dissolve the perception gap of that soft. (author)

  4. Analysis of photonic band-gap structures in stratified medium

    DEFF Research Database (Denmark)

    Tong, Ming-Sze; Yinchao, Chen; Lu, Yilong

    2005-01-01

    Purpose - To demonstrate the flexibility and advantages of a non-uniform pseudo-spectral time domain (nu-PSTD) method through studies of the wave propagation characteristics on photonic band-gap (PBG) structures in stratified medium Design/methodology/approach - A nu-PSTD method is proposed...... in solving the Maxwell's equations numerically. It expands the temporal derivatives using the finite differences, while it adopts the Fourier transform (FT) properties to expand the spatial derivatives in Maxwell's equations. In addition, the method makes use of the chain-rule property in calculus together...... with the transformed space technique in order to make the algorithm flexible in terms of non-uniform spatial sampling. Findings - Through the studies of the wave propagation characteristics on PBG structures in stratified medium, it has been found that the proposed method retains excellent accuracy in the occasions...

  5. Nuclear Structure in China 2010

    Science.gov (United States)

    Bai, Hong-Bo; Meng, Jie; Zhao, En-Guang; Zhou, Shan-Gui

    2011-08-01

    Personal view on nuclear physics research / Jie Meng -- High-spin level structures in [symbol]Zr / X. P. Cao ... [et al.] -- Constraining the symmetry energy from the neutron skin thickness of tin isotopes / Lie-Wen Chen ... [et al.] -- Wobbling rotation in atomic nuclei / Y. S. Chen and Zao-Chun Gao -- The mixing of scalar mesons and the possible nonstrange dibaryons / L. R. Dai ... [et al.] -- Net baryon productions and gluon saturation in the SPS, RHIC and LHC energy regions / Sheng-Qin Feng -- Production of heavy isotopes with collisions between two actinide nuclides / Z. Q. Feng ... [et al.] -- The projected configuration interaction method / Zao-Chun Gao and Yong-Shou Chen -- Applications of Nilsson mean-field plus extended pairing model to rare-earth nuclei / Xin Guan ... [et al.] -- Complex scaling method and the resonant states / Jian-You Guo ... [et al.] -- Probing the equation of state by deep sub-barrier fusion reactions / Hong-Jun Hao and Jun-Long Tian -- Doublet structure study in A[symbol]105 mass region / C. Y. He ... [et al.] -- Rotational bands in transfermium nuclei / X. T. He -- Shape coexistence and shape evolution [symbol]Yb / H. Hua ... [et al.] -- Multistep shell model method in the complex energy plane / R. J. Liotta -- The evolution of protoneutron stars with kaon condensate / Ang Li -- High spin structures in the [symbol]Lu nucleus / Li Cong-Bo ... [et al.] -- Nuclear stopping and equation of state / QingFeng Li and Ying Yuan -- Covariant description of the low-lying states in neutron-deficient Kr isotopes / Z. X. Li ... [et al.] -- Isospin corrections for superallowed [symbol] transitions / HaoZhao Liang ... [et al.] -- The positive-parity band structures in [symbol]Ag / C. Liu ... [et al.] -- New band structures in odd-odd [symbol]I and [symbol]I / Liu GongYe ... [et al.] -- The sd-pair shell model and interacting boson model / Yan-An Luo ... [et al.] -- Cross-section distributions of fragments in the calcium isotopes projectile

  6. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    1992-05-01

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e + e - problem and heavy ion dynamics

  7. Nuclear Structure Data for the Present Age

    International Nuclear Information System (INIS)

    Baglin, Coral M.

    2005-01-01

    The US Nuclear Data Program maintains and provides easy and free access to several comprehensive databases that assist scientists to sift through and assess the vast quantity of published nuclear structure and decay data. These databases are an invaluable asset for nuclear-science experimentalists and theorists alike, and the recommended values provided for nuclear properties such as decay modes, level energies and lifetimes, and radiation properties can also be of great importance to specialists in other fields such as medicine, geophysics, and reactor design. The Evaluated Nuclear Structure Data File (ENSDF) contains experimental nuclear structure data for all known nuclides, evaluated by the US nuclear data program evaluators in collaboration with a number of international data groups; the Nuclear Science Reference (NSR) database provides complementary bibliographic information; the Experimental Unevaluated Nuclear Data Listing (XUNDL) exists to enable rapid access to experimental nuclear-structure data compiled from the most recent publications (primarily in high-spin physics). This paper presents an overview of the nuclear structure and decay data available through these databases, with emphasis on recent and forthcoming additions to and presentations of the available material

  8. Theoretical nuclear structure and astrophysics at FAIR

    International Nuclear Information System (INIS)

    Rodríguez, Tomás R

    2014-01-01

    Next generation of radioactive ion beam facilities like FAIR will open a bright future for nuclear structure and nuclear astrophysics research. In particular, very exotic nuclei (mainly neutron rich) isotopes will be produced and a lot of new exciting experimental data will help to test and improve the current nuclear models. In addition, these data (masses, reaction cross sections, beta decay half-lives, etc.) combined with the development of better theoretical approaches will be used as the nuclear physics input for astrophysical simulations. In this presentation I will review some of the state-of-the-art nuclear structure methods and their applications.

  9. Optimization of gap sizes for the high performance of annular nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Young Doo; Kwon, Soon Bum; Cho, Hui Jeong; Kim, Seong Su [Kyungpook National University, Daegu (Korea, Republic of)

    2015-04-15

    Solid-type nuclear fuels have been used for nuclear reactors for a long time. Many countries are currently developing annular fuels to improve the efficiency of nuclear fuels. The thermoelastic-plastic-creep analyses of solid- and annular-type rods were conducted under the same conditions. The temperature and stress of the solid- and annular-type rods were compared on the basis of gap size. In this study, we examined the advantages and disadvantages of annular-type fuel regarding the temperature and stress of the pellet and cladding. The inner and outer gaps between the pellet and cladding play important roles in the temperature and stress distributions of fuel systems. Therefore, the optimization of gaps in fuel systems was conducted for a low temperature under certain stress conditions. hermoelasticplastic-creep analyses were conducted by using an in-house thermoelastic-plastic-creep finite element analysis program in Visual FORTRAN with the effective stress function algorithm. Nonlinear iterative stress analyses were conducted by nonlinear iterative temperature analyses; that is, a quasi-fully coupled algorithm was applied to this procedure. In this study, the thermoelastic-plastic-creep analysis of pressurized water reactor annular fuels was conducted to determine the contacting tendency of the inner-outer gaps between the annular fuel pellets and cladding, as well as to optimize the gap sizes by using the commercial package PIAnO for efficient heat transfer at certain stress levels. Most analyses were conducted until the gaps disappeared. However, certain analyses lasted for 1582 days, after which the fuels were replaced.

  10. Nuclear Structure and Decay Data (NSDD) network

    International Nuclear Information System (INIS)

    Pronyaev, V.G.

    2001-02-01

    This report provides a brief description of the Nuclear Structure and Decay Data (NSDD) Network in response to a request from the Advisory Group Meeting on ''Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators'' (IAEA, Vienna, 14-17 December 1998, report IAEA(NDS)-399 (1999)). This report supersedes the special issue of the Nuclear Data Newsletter No. 20 published in November 1994. (author)

  11. Effects of annular air gaps surrounding an emplaced nuclear waste canister in deep geologic storage

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, W.E.; Davis, B.W.; Cheung, H.

    1980-06-05

    Annular air spaces surrounding an emplaced nuclear waste canister in deep geologic storage will have significant effects on the long-term performance of the waste form. Addressed specifically in this analysis is the influence of a gap on the thermal response of the waste package. Three dimensional numerical modeling predicts temperature effects for a series of parameter variations, including the influence of gap size, surface emissivities, initial thermal power generation of the canister, and the presence/absence of a sleeve. Particular emphasis is placed on determining the effects these variables have on the canister surface temperature. We have identified critical gap sizes at which the peak transient temperature occurs when gap widths are varied for a range of power levels. It is also shown that high emissivities for the heat exchanging surfaces are desirable, while that of the canister surface has the greatest influence. Gap effects are more pronounced, and therefore more effort should be devoted to optimal design, in situations where the absolute temperature of the near field medium is high. This occurs for higher power level emplacements and in geomedia with low thermal conductivities. Finally, loosely inserting a sleeve in the borehole effectively creates two gaps and drastically raises the canister peak temperature. It is possible to use these results in the design of an optimum package configuration which will maintain the canister at acceptable temperature levels. A discussion is provided which relates these findings to NRC regulatory considerations.

  12. Bridging technology gaps in realizing goals towards peaceful uses of nuclear energy

    International Nuclear Information System (INIS)

    Mohanty, P.R.; Haldar, T.K.

    2009-01-01

    India is committed towards peaceful uses of Nuclear Energy and Nuclear Power occupies its centre stage. In the nuclear fuel cycle, apart from the fuel material itself, the programme needs a host of other materials in specific physical and chemical form. In this context, Heavy Water Board, a constituent unit of DAE, initiated technology development campaigns centering around three broad areas, i.e Specialty chemicals like organo-phosphorus solvents; solvent extraction technology including suitable equipment for use as liquid-liquid contacting device; and stable isotope like Boron-10. In a short span of about 7 years, it has successfully developed, demonstrated and deployed these technologies. This article gives an overview of these activities and the strategy adopted towards bridging technology gaps in realizing goals towards peaceful uses of Nuclear Energy. (author)

  13. Identification and Analysis of Critical Gaps in Nuclear Fuel Cycle Codes Required by the SINEMA Program

    Energy Technology Data Exchange (ETDEWEB)

    Adrian Miron; Joshua Valentine; John Christenson; Majd Hawwari; Santosh Bhatt; Mary Lou Dunzik-Gougar: Michael Lineberry

    2009-10-01

    The current state of the art in nuclear fuel cycle (NFC) modeling is an eclectic mixture of codes with various levels of applicability, flexibility, and availability. In support of the advanced fuel cycle systems analyses, especially those by the Advanced Fuel Cycle Initiative (AFCI), Unviery of Cincinnati in collaboration with Idaho State University carried out a detailed review of the existing codes describing various aspects of the nuclear fuel cycle and identified the research and development needs required for a comprehensive model of the global nuclear energy infrastructure and the associated nuclear fuel cycles. Relevant information obtained on the NFC codes was compiled into a relational database that allows easy access to various codes' properties. Additionally, the research analyzed the gaps in the NFC computer codes with respect to their potential integration into programs that perform comprehensive NFC analysis.

  14. Identification and Analysis of Critical Gaps in Nuclear Fuel Cycle Codes Required by the SINEMA Program

    International Nuclear Information System (INIS)

    Miron, Adrian; Valentine, Joshua; Christenson, John; Hawwari, Majd; Bhatt, Santosh; Dunzik-Gougar, Mary Lou; Lineberry, Michael

    2009-01-01

    The current state of the art in nuclear fuel cycle (NFC) modeling is an eclectic mixture of codes with various levels of applicability, flexibility, and availability. In support of the advanced fuel cycle systems analyses, especially those by the Advanced Fuel Cycle Initiative (AFCI), University of Cincinnati in collaboration with Idaho State University carried out a detailed review of the existing codes describing various aspects of the nuclear fuel cycle and identified the research and development needs required for a comprehensive model of the global nuclear energy infrastructure and the associated nuclear fuel cycles. Relevant information obtained on the NFC codes was compiled into a relational database that allows easy access to various codes' properties. Additionally, the research analyzed the gaps in the NFC computer codes with respect to their potential integration into programs that perform comprehensive NFC analysis.

  15. Method of manufacturing flexible metallic photonic band gap structures, and structures resulting therefrom

    Science.gov (United States)

    Gupta, Sandhya; Tuttle, Gary L.; Sigalas, Mihail; McCalmont, Jonathan S.; Ho, Kai-Ming

    2001-08-14

    A method of manufacturing a flexible metallic photonic band gap structure operable in the infrared region, comprises the steps of spinning on a first layer of dielectric on a GaAs substrate, imidizing this first layer of dielectric, forming a first metal pattern on this first layer of dielectric, spinning on and imidizing a second layer of dielectric, and then removing the GaAs substrate. This method results in a flexible metallic photonic band gap structure operable with various filter characteristics in the infrared region. This method may be used to construct multi-layer flexible metallic photonic band gap structures. Metal grid defects and dielectric separation layer thicknesses are adjusted to control filter parameters.

  16. Narrow gap mechanised arc welding in nuclear components manufactured by AREVA NP

    International Nuclear Information System (INIS)

    Peigney, A.

    2007-01-01

    Nuclear components require welds of irreproachable and reproducible quality. Moreover, for a given welding process, productivity requirements lead to reduce the volume of deposited metal and thus to use narrow gap design. In the shop, narrow gap Submerged Arc Welding process (SAW) is currently used on rotating parts in flat position for thicknesses up to 300 mm. Welding is performed with one or two wires in two passes per layer. In Gas Tungsten Arc Welding process (GTAW), multiple applications can be found because this process presents the advantage of allowing welding in all positions. Welding is performed in one or two passes per layer. The process is used in factory and on the nuclear sites for assembling new components but also for replacing components and for repairs. Presently, an increase of productivity of the process is sought through the use of hot wire and/or two wires. Concerning Gas Metal Arc Welding process (GMAW), its use is growing for nuclear components, including narrow gap applications. This process, limited in its applications in the past on account of the defects it generated, draws benefit from the progress of the welding generators. Then it is possible to use this efficient process for high security components such as those of nuclear systems. It is to be noted that the process is applicable in the various welding positions as it is the case for GTAW, while being more efficient than the latter. This paper presents the state of the art in the use of narrow gap mechanised arc welding processes by AREVA NP units. (author) [fr

  17. True photonic band-gap mode-control in VCSEL structures

    DEFF Research Database (Denmark)

    Romstad, F.; Madsen, M.; Birkedal, Dan

    2003-01-01

    Photonic band-gap mode confinement in novel nano-structured large area VCSEL structures is confirmed by the amplified spontaneous emission spectrum. Both guide and anti-guide VCSEL structures are experimentally characterised to verify the photonic band-gap effect.......Photonic band-gap mode confinement in novel nano-structured large area VCSEL structures is confirmed by the amplified spontaneous emission spectrum. Both guide and anti-guide VCSEL structures are experimentally characterised to verify the photonic band-gap effect....

  18. Gap symmetry and structure of Fe-based superconductors

    International Nuclear Information System (INIS)

    Hirschfeld, P J; Korshunov, M M; Mazin, I I

    2011-01-01

    The recently discovered Fe-pnictide and chalcogenide superconductors display low-temperature properties suggesting superconducting gap structures which appear to vary substantially from family to family, and even within families as a function of doping or pressure. We propose that this apparent nonuniversality can actually be understood by considering the predictions of spin fluctuation theory and accounting for the peculiar electronic structure of these systems, coupled with the likely 'sign-changing s-wave' (s ± ) symmetry. We review theoretical aspects, materials properties and experimental evidence relevant to this suggestion, and discuss which further measurements would be useful to settle these issues. Satisfactoriness has to be measured by a multitude of standards, of which some, for aught we know, may fail in any given case; and what is more satisfactory than any alternative in sight, may to the end be a sum of pluses and minuses, concerning which we can only trust that by ulterior corrections and improvements a maximum of the one and a minimum of the other may some day be approached. William James, Meaning of Truth

  19. Nuclear Structure Committee annual report 1976-1977, nuclear structure grants and laboratory agreements

    International Nuclear Information System (INIS)

    1977-01-01

    The Annual Report for the period 1 August 1976 to 31 July 1977 of the Nuclear Structure Committee of the Nuclear Physics Board, under the (United Kingdom) Science Research Council, is presented. Details are given of nuclear structure grants and laboratory agreements. (U.K.)

  20. Complete flexural vibration band gaps in membrane-like lattice structures

    International Nuclear Information System (INIS)

    Yu Dianlong; Liu Yaozong; Qiu Jing; Wang Gang; Zhao Honggang

    2006-01-01

    The propagation of flexural vibration in the periodical membrane-like lattice structure is studied. The band structure calculated with the plane wave expansion method indicates the existence of complete gaps. The frequency response function of a finite periodic structure is simulated with finite element method. Frequency ranges with vibration attenuation are in good agreement with the gaps found in the band structure. Much larger attenuations are found in the complete gaps comparing to those directional ones. The existence of complete flexural vibration gaps in such a lattice structure provides a new idea for vibration control of thin plates

  1. Nuclear pore structure: warming up the core.

    Science.gov (United States)

    Harel, Amnon; Gruenbaum, Yosef

    2011-07-22

    Structural determination of the nuclear pore complex has been limited by the complexity and size of this cellular megalith. By taking advantage of exceptionally stable nucleoporins from the thermophilic fungus Chaetomium thermophilum, Amlacher et al. (2011) provide new insight into a core element of the nuclear pore scaffold. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. NRSAS: Nuclear Receptor Structure Analysis Servers.

    NARCIS (Netherlands)

    Bettler, E.J.M.; Krause, R.; Horn, F.; Vriend, G.

    2003-01-01

    We present a coherent series of servers that can perform a large number of structure analyses on nuclear hormone receptors. These servers are part of the NucleaRDB project, which provides a powerful information system for nuclear hormone receptors. The computations performed by the servers include

  3. Salary Structure Effects and the Gender Pay Gap in Academia

    Science.gov (United States)

    Barbezat, Debra A.; Hughes, James W.

    2005-01-01

    This paper presents estimates of the gender salary gap and discrimination based on the most recent national faculty survey data. New estimates for 1999 indicate that male faculty members still earn 20.7% more than comparable female colleagues. Depending upon which decomposition technique is employed, the portion of this gap attributable to…

  4. Closing the gap between short- and long-term scenarios for nuclear energy

    International Nuclear Information System (INIS)

    Toth, F. L.; Rogner, H.-H.

    2005-01-01

    Many scenarios published in recent years explore the driving forces and assess plausible ranges of global energy use and the resources they draw on. Some scenarios (e.g., OECD IEA, Organization for Economic Co-operation and Development International Energy Agency, 2004) focus on the next decade or two and project the evolution of world energy demand, supply as well as the resources, technologies, and prices to match them. Other scenarios (e.g., the Special Report on Emissions Scenarios, SRES, prepared by the Intergovernmental Panel on Climate Change, IPCC, 2000) explore the long term with a view to resource availability and depletion, technological transformations, and environmental concerns, predominantly climate change. A persistent gap (see Figure 1) can be observed in the projections for nuclear energy: near-term scenarios typically project a flat or slightly declining contribution of nuclear energy to the world energy supply whereas medium- and long-term scenarios anticipate significant increases. The magnitude of the gap between the OECD IEA (2002) projections and the median of the 40 IPCC SRES scenarios for the year 2020 amounts to almost 300 GWe installed capacity. Reasons for the gap originate in the differences between the analytical frameworks (including projection techniques) adopted by the short- and long-term studies. Another, closely related reason is the difference in the underlying assumptions, particularly their relations to recent trends and the current situation. In addition, near-term projections are heavily influenced by the social context (perceived unpopularity or outright rejection of nuclear power after Chernobyl), political factors (government pronouncements and policies at the national level, diplomacy and balancing of national positions at international organizations), economic aspects (energy market deregulation and liberalization unveiling excess capacities; financial risks), technology matters (the role of learning, definition of

  5. Electromagnetic studies of nuclear structure and reactions

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, F.W.; Dawson, J.F.; Heisenberg, J.H.; Calarco, J.R.

    1990-06-01

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation.

  6. Structural dynamic analysis of nuclear power plants

    International Nuclear Information System (INIS)

    Halbritter, A.L.; Koishi, N.; Prates, C.L.M.

    1986-01-01

    One of the most important items to be considered in order to guarantee the safety conditions of a Nuclear Power Plant is the design of the civil structures, the electrical and mechanical components and piping system taking into account non-conventional loading cases, e.g. earthquakes and explosions pressure waves. The general procedures used in the structural dynamic analysis of Nuclear Power Plants are presented, specially for seismic and explosion loads. (Author) [pt

  7. Bridging the energy gap through small and medium sized nuclear reactors in India

    International Nuclear Information System (INIS)

    Srivastava, R.

    1987-01-01

    India is the only country in the world which is employing small sized nuclear reactors for its nuclear power programme. It has now embarked on a programme of augmenting the contribution of the nuclear power by way of employing both medium and small sized nuclear reactors in the next 15 years. This paper discusses the Indian experience and its efforts for industrial mobilisation for rapidly constructing 235/500 MWe nuclear reactor units in a period of about 8 to 9 years. The current energy situation in India and this context the near term role of nuclear power for supplementing the existing sources of commercial energy have been evaluated. Nuclear power has reached such a stage of maturity whereby it has now become a commercially viable source of electricity and it could be utilised on large scale to bridge the energy gap. At present six reactor units of 210/235 MWe capacity are in operation and eight more are in different stages of construction. While we are continuing with the construction of 235 MWe units, a programme of being pursued to construct 550 MWe capacity reactor units from midnineties onwards. This has become possible with the strengthening of regional electricity grids and simultaneous efforts undertaken for augmentation of fuel supply, heavy water production and industrial infrastructure. For a developing country like India, implementation of a sizable nuclear power programme has posed certain special challenges as major inputs are required to be made available with indigeneous efforts. This paper discusses such challenges and presents the ways and means adopted to surmount them. Other developing countries with conditions comparable to those in India could benefit from Indian experience in this regard. This paper also proposes India's willingness to cooperate with other countries for exchange of information and assistance in terms of technical knowhow. (author)

  8. Structure-soil-structure interaction of nuclear structures

    International Nuclear Information System (INIS)

    Snyder, M.D.; Shaw, D.E.; Hall, J.R. Jr.

    1975-01-01

    Structure-to-structure interaction resulting from coupling of the foundations through the soil has traditionally been neglected in the seismic analysis of nuclear power plants. This paper examines the phenomenon and available methods of analytical treatment, including finite element and lumped parameter methods. Finite element techniques have lead to the treatment of through soil coupling of structural foundations using two dimensional plane strain models owing to the difficulty of considering three dimensional finite element models. The coupling problem is treated by means of a lumped parameter model derived from elastic half-space considerations. Consequently, the method is applicable to the interaction of any number of foundations and allows the simultaneous application of tri-directional excitation. The method entails the idealization of interacting structures as lumped mass/shear beams with lumped soil springs and dampers beneath each foundation plus a coupling matrix between the interacting foundations. Utilizing classical elastic half-space methods, the individual foundation soil springs and dampers may be derived, accounting for the effects of embedment and soil layering, analogous to the methods used for single soil-structure, interaction problems. The coupling matrix is derived by generating influence coefficients based on the geometric relationship of the structures using classical half-space solutions. The influence coefficients form the coupling flexibility matrix which is inverted to yield the coupling matrix for the lumped parameter model

  9. Structural materials for innovative nuclear systems (SMINS)

    International Nuclear Information System (INIS)

    2008-01-01

    Structural materials research is a field of growing relevance in the nuclear sector, especially for the different innovative reactor systems being developed within the Generation IV International Forum (GIF), for critical and subcritical transmutation systems, and of interest to the Global Nuclear Energy Partnership (GNEP). Under the auspices of the NEA Nuclear Science Committee (NSC) the Workshop on Structural Materials for Innovative Nuclear Systems (SMINS) was organised in collaboration with the Forschungszentrum Karlsruhe in Germany. The objectives of the workshop were to exchange information on structural materials research issues and to discuss ongoing programmes, both experimental and in the field of advanced modelling. These proceedings include the papers and the poster session materials presented at the workshop, representing the international state of the art in this domain. (author)

  10. Nucleon isobars in nuclear structure

    International Nuclear Information System (INIS)

    Green, A.M.

    1978-01-01

    Present day uncertainties in the theory of nuclear matter, which indicate that there is room for the large corrections that appear when Δs are treated explicitly, are considered. The role that the Δ plays in exchange currents, in the two-nucleon potential, and in three-body potentials is examined. The form of the transition potential, generation of isobar configurations and the effect of isobars in few nucleon systems are considered. (U.K.)

  11. Nuclear structure studies at Saha Institute of Nuclear Physics using ...

    Indian Academy of Sciences (India)

    Abstract. In-beam gamma-ray spectroscopy, carried out at the Saha Institute of Nuclear Physics in the recent past, using heavy-ion projectiles from the pelletron accelerator centres in the country and multi-detector arrays have yielded significant data on the structure of a large number of nuclei spanning different mass ...

  12. Nuclear structure studies at Saha Institute of Nuclear Physics using ...

    Indian Academy of Sciences (India)

    In-beam gamma-ray spectroscopy, carried out at the Saha Institute of Nuclear Physics in the recent past, using heavy-ion projectiles from the pelletron accelerator centres in the country and multi-detector arrays have yielded significant data on the structure of a large number of nuclei spanning different mass regions.

  13. Subharmonic gap structure in the characteristics of YBa2Cu3O7-x microbridges

    International Nuclear Information System (INIS)

    Pogrebnyakov, A.V.; Levinsen, M.T.; Sheng, Y.Q.; Freltoft, T.

    1996-01-01

    The subharmonic gap structures corresponding to large, 2Δ 1 =48 meV, and small, 2Δ 2 =10.3 meV, components of the energy gap were observed in the first derivatives of the current-voltage characteristics of YBa 2 Cu 3 O 7-x epitaxial thin film microbridges. The appearance of the subharmonic gap structures is attributed to Andreev reflection. (orig.)

  14. Structural mechanics in nuclear power plant

    International Nuclear Information System (INIS)

    Han Liangbi

    1998-01-01

    The main research works in structural mechanics in reactor technology are emphatically introduced. It is completed by structural mechanics engineers at Shanghai Nuclear Research and Design Institute associated with the design and construction problems for Qinshan NPP Unit 1 and Pakistani CHASNUPP. About structural mechanics problem for the containment, the rock and soft soil two different bases are considered. For the later the interaction between soil and structure is carefully studied. About the structural mechanics problem for the equipment and pipings, the three dimensional stress and fracture analyses are studied. For the structural dynamics problem, including flow induced vibration, the response analyses under earthquake and loss coolant accident loadings are studied. For pipings, the leak before break technique has been emphatically introduced. A lot of mathematical models, the used computer codes, analytical calculations and experimental results are also introduced. This is a comprehensive description about structural mechanics problem in pressurized water reactor nuclear power plant

  15. On elastic structural elements for nuclear reactors

    International Nuclear Information System (INIS)

    Povolo, F.

    1978-03-01

    The in-pile stress-relaxation behaviour of materials usually employed for the elastic structural elements, in nuclear reactors, is critically reviewed and the results are compared with those obtained in commercial zirconium alloys irradiated under similar conditions. Finally, it is shown that, under certain conditions, some zirconium alloys may be used as an alternative material for these structural elements. (orig.) [de

  16. Progress report on nuclear structure studies

    International Nuclear Information System (INIS)

    Walters, W.B.

    1991-01-01

    In this report, new results are reported for the decay and nuclear orientation of 114,116 I and 114 Sb as well as data for the structure of daughter nuclides 114,116 Te. New results for IBM-2 calculations for the structure of 126 Xe are also reported. 6 figs., 5 tabs

  17. Theoretical nuclear structure. Progress report for 1997

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Strayer, M.R.

    1997-01-01

    This research effort is directed toward theoretical support and guidance for the fields of radioactive ion beam physics, gamma-ray spectroscopy, and the interface between nuclear structure and nuclear astrophysics. The authors report substantial progress in all these areas. One measure of progress is publications and invited material. The research described here has led to more than 25 papers that are published, accepted, or submitted to refereed journals, and to 25 invited presentations at conferences and workshops

  18. Nuclear structure at intermediate energies

    International Nuclear Information System (INIS)

    Bonner, B.E.; Mutchler, G.S.

    1991-01-01

    The theme that unites the sometimes seemingly disparate experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in their radiative decays in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of our BNL experiments E810, E854, as well as our approved experiment at RHIC), -- all these projects share this common goal. Our other experiments represent different approaches to the same broad undertaking. LAMPF E1097 will provide definitive answers to the question of the spin dependence of the inelastic channel of pion production in the n-p interaction. FNAL E683 may well open a new field of investigation in nuclear physics: that of just how quarks and gluons interact with nuclear matter as they transverse nuclei of different sizes. In most all of the experiments mentioned above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are unavailable to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do

  19. Nuclear structure at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B.E.; Mutchler, G.S.

    1991-09-30

    The theme that unites the sometimes seemingly disparate experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in their radiative decays in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of our BNL experiments E810, E854, as well as our approved experiment at RHIC), -- all these projects share this common goal. Our other experiments represent different approaches to the same broad undertaking. LAMPF E1097 will provide definitive answers to the question of the spin dependence of the inelastic channel of pion production in the n-p interaction. FNAL E683 may well open a new field of investigation in nuclear physics: that of just how quarks and gluons interact with nuclear matter as they transverse nuclei of different sizes. In most all of the experiments mentioned above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are unavailable to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do.

  20. Radiation damage studies of nuclear structural materials

    International Nuclear Information System (INIS)

    Barat, P.

    2012-01-01

    Maximum utilization of fuel in nuclear reactors is one of the important aspects for operating them economically. The main hindrance to achieve this higher burnups of nuclear fuel for the nuclear reactors is the possibility of the failure of the metallic core components during their operation. Thus, the study of the cause of the possibility of failure of these metallic structural materials of nuclear reactors during full power operation due to radiation damage, suffered inside the reactor core, is an important field of studies bearing the basic to industrial scientific views.The variation of the microstructure of the metallic core components of the nuclear reactors due to radiation damage causes enormous variation in the structure and mechanical properties. A firm understanding of this variation of the mechanical properties with the variation of microstructure will serve as a guide for creating new, more radiation-tolerant materials. In our centre we have irradiated structural materials of Indian nuclear reactors by charged particles from accelerator to generate radiation damage and studied the some aspects of the variation of microstructure by X-ray diffraction studies. Results achieved in this regards, will be presented. (author)

  1. Impact of Scaffolding and Question Structure on the Gender Gap

    Science.gov (United States)

    Dawkins, Hillary; Hedgeland, Holly; Jordan, Sally

    2017-01-01

    We address previous hypotheses about possible factors influencing the gender gap in attainment in physics. Specifically, previous studies claim that scaffolding may preferentially benefit female students, and we present some alternative conclusions surrounding this hypothesis. By taking both student attainment level and the degree of question…

  2. The band gap variation of a two dimensional binary locally resonant structure in thermal environment

    Directory of Open Access Journals (Sweden)

    Zhen Li

    2017-01-01

    Full Text Available In this study, the numerical investigation of thermal effect on band gap dynamical characteristic for a two-dimensional binary structure composed of aluminum plate periodically filled with nitrile rubber cylinder is presented. Initially, the band gap of the binary structure variation trend with increasing temperature is studied by taking the softening effect of thermal stress into account. A breakthrough is made which found the band gap being narrower and shifting to lower frequency in thermal environment. The complete band gap which in higher frequency is more sensitive to temperature that it disappears with temperature increasing. Then some new transformed models are created by changing the height of nitrile rubber cylinder from 1mm to 7mm. Simulations show that transformed model can produce a wider band gap (either flexure or complete band gap. A proper forbidden gap of elastic wave can be utilized in thermal environment although both flexure and complete band gaps become narrower with temperature. Besides that, there is a zero-frequency flat band appearing in the first flexure band, and it becomes broader with temperature increasing. The band gap width decreases trend in thermal environment, as well as the wider band gap induced by the transformed model with higher nitrile rubber cylinder is useful for the design and application of phononic crystal structures in thermal environment.

  3. Nuclear Structure Research at Richmond

    Energy Technology Data Exchange (ETDEWEB)

    Beausang, Cornelius W. [Univ. of Richmond, VA (United States)

    2015-04-30

    The goals for the final year were; (1) to continue ongoing efforts to develop and enhance GRETINA and work towards GRETA; (2) to investigate the structure of non-yrast states in shape transitional Sm and Gd nuclei; (3) to investigate the structure of selected light Cd nuclei; (4) to exploit the surrogate reaction technique to extract (n,f) cross sections for actinide nuclei, particularly the first measurement of the 236Pu and 237Pu(n,f) cross sections.

  4. Low frequency torsional vibration gaps in the shaft with locally resonant structures

    International Nuclear Information System (INIS)

    Yu Dianlong; Liu Yaozong; Wang Gang; Cai Li; Qiu Jing

    2006-01-01

    The propagation of torsional wave in the shaft with periodically attached local resonators is studied with the transfer matrix theory and the finite element method. The analytical dispersion relation and the complex band structure of such a structure is presented for the first time, which indicates the existence of low frequency gaps. The effect of shaft material on the vibration attenuation in band gap is investigated. The frequency response function of the shaft with finite periodic locally resonant oscillators is simulated with finite element method, which shows large vibration attenuation in the frequency range of the gap as expected. The low frequency torsional gap in shafts provides a new idea for vibration control

  5. Quasi-free scattering and nuclear structure

    International Nuclear Information System (INIS)

    Vasconcellos, C.A.Z.

    1982-01-01

    In quasi-free scatterings the knocked-out nucleon is in general effectively polarized. This polarization can be observed by using polarized incoming protons. The effective polarization of the knocked-out nucleon is heavily dependent on certain spin correlations. Therefore the quasi-free reaction may be used as a method to investigate nuclear structure. Effective polarization for the reactions 14 N(p,2p) 13 C and 6 Li(p,2p) 5 He are considered using the following nuclear structure models: [jj] coupling shell model, [LS] coupling and a [deuteron-core] cluster model. (Author) [pt

  6. Reliability assessment of nuclear structural systems

    International Nuclear Information System (INIS)

    Reich, M.; Hwang, H.

    1983-01-01

    Reliability assessment of nuclear structural systems has been receiving more emphasis over the last few years. This paper deals with the recent progress made by the Structural Analysis Division of Brookhaven National Laboratory (BNL), in the development of a probability-based reliability analysis methodology for safety evaluation of reactor containments and other seismic category I structures. An important feature of this methodology is the incorporation of finite element analysis and random vibration theory. By utilizing this method, it is possible to evaluate the safety of nuclear structures under various static and dynamic loads in terms of limit state probability. Progress in other related areas, such as the establishment of probabilistic characteristics for various loads and structural resistance, are also described. Results of an application of the methodology to a realistic reinforced concrete containment subjected to dead and live loads, accidental internal pressures and earthquake ground accelerations are presented

  7. Impact of scaffolding and question structure on the gender gap

    Science.gov (United States)

    Dawkins, Hillary; Hedgeland, Holly; Jordan, Sally

    2017-12-01

    We address previous hypotheses about possible factors influencing the gender gap in attainment in physics. Specifically, previous studies claim that scaffolding may preferentially benefit female students, and we present some alternative conclusions surrounding this hypothesis. By taking both student attainment level and the degree of question scaffolding into account, we identify questions that exhibit real bias in favor of male students. We find that both multidimensional context and use of diagrams are common elements of such questions.

  8. Nuclear structure of $^{231}$Ac

    CERN Document Server

    Boutami, R; Mach, H; Kurcewicz, W; Fraile, L M; Gulda, K; Aas, A J; García-Raffi, L M; Løvhøiden, G; Martínez, T; Rubio, B; Taín, J L; Tengblad, O

    2008-01-01

    The low-energy structure of 231Ac has been investigated by means of gamma ray spectroscopy following the beta-decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

  9. Nuclear structure of 231Ac

    International Nuclear Information System (INIS)

    Boutami, R.; Borge, M.J.G.; Mach, H.; Kurcewicz, W.; Fraile, L.M.; Gulda, K.; Aas, A.J.; Garcia-Raffi, L.M.; Lovhoiden, G.; Martinez, T.; Rubio, B.; Tain, J.L.; Tengblad, O.

    2008-01-01

    The low-energy structure of 231 Ac has been investigated by means of γ ray spectroscopy following the β - decay of 231 Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of 231 Ra → 231 Ac has been constructed for the first time. The Advanced Time Delayed βγγ(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus

  10. Design and Additive Manufacturing of 3D Phononic Band Gap Structures Based on Gradient Based Optimization

    Directory of Open Access Journals (Sweden)

    Maximilian Wormser

    2017-09-01

    Full Text Available We present a novel approach for gradient based maximization of phononic band gaps. The approach is a geometry projection method combining parametric shape optimization with density based topology optimization. By this approach, we obtain, in a two dimension setting, cellular structures exhibiting relative and normalized band gaps of more than 8 and 1.6, respectively. The controlling parameter is the minimal strut size, which also corresponds with the obtained stiffness of the structure. The resulting design principle is manually interpreted into a three dimensional structure from which cellular metal samples are fabricated by selective electron beam melting. Frequency response diagrams experimentally verify the numerically determined phononic band gaps of the structures. The resulting structures have band gaps down to the audible frequency range, qualifying the structures for an application in noise isolation.

  11. Design and Additive Manufacturing of 3D Phononic Band Gap Structures Based on Gradient Based Optimization.

    Science.gov (United States)

    Wormser, Maximilian; Wein, Fabian; Stingl, Michael; Körner, Carolin

    2017-09-22

    We present a novel approach for gradient based maximization of phononic band gaps. The approach is a geometry projection method combining parametric shape optimization with density based topology optimization. By this approach, we obtain, in a two dimension setting, cellular structures exhibiting relative and normalized band gaps of more than 8 and 1.6, respectively. The controlling parameter is the minimal strut size, which also corresponds with the obtained stiffness of the structure. The resulting design principle is manually interpreted into a three dimensional structure from which cellular metal samples are fabricated by selective electron beam melting. Frequency response diagrams experimentally verify the numerically determined phononic band gaps of the structures. The resulting structures have band gaps down to the audible frequency range, qualifying the structures for an application in noise isolation.

  12. Development of a simplified fuel-cladding gap conductance model for nuclear feedback calculation in 16x16 FA

    International Nuclear Information System (INIS)

    Yoo, Jong Sung; Park, Chan Oh; Park, Yong Soo

    1995-01-01

    The accurate determination of the fuel-cladding gap conductance as functions of rod burnup and power level may be a key to the design and safety analysis of a reactor. The incorporation of a sophisticated gap conductance model into nuclear design code for computing thermal hydraulic feedback effect has not been implemented mainly because of computational inefficiency due to complicated behavior of gap conductance. To avoid the time-consuming iteration scheme, simplification of the gap conductance model is done for the current design model. The simplified model considers only the heat conductance contribution to the gap conductance. The simplification is made possible by direct consideration of the gap conductivity depending on the composition of constituent gases in the gap and the fuel-cladding gap size from computer simulation of representative power histories. The simplified gap conductance model is applied to the various fuel power histories and the predicted gap conductances are found to agree well with the results of the design model

  13. QCD Structure of Nuclear Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Granados, Carlos [Florida Intl Univ., Miami, FL (United States)

    2011-05-25

    This dissertation investigated selected processes involving baryons and nuclei in hard scattering reactions. Through these processes, this work explored the constituent structure of baryons and the mechanisms through which the interactions between these constituents ultimately control the selected reactions. First, hard nucleon-nucleon elastic scattering was studied considering the quark exchange (QE) between the nucleons to be the dominant mechanism of interaction in the constituent picture. It was found that an angular asymmetry exhibited by proton-neutron (pn) elastic scattering data is explained within this framework if a quark-diquark picture dominates the nucleon's structure instead of a more traditional SU(6) model. The latter yields an asymmetry around 90 deg center of mass scattering with a sign opposite to what is experimentally observed. The second process is the hard breakup by a photon of a nucleon-nucleon system in light nuclei. Proton-proton (pp) and pn breakup in 3He, and double Δ-isobars production in deuteron breakup were analyzed in the hard rescattering model (HRM), which in conjunction with the QE mechanism provides a QCD description of the reaction. Cross sections for both channels in 3He photodisintegration were computed without the need of a fitting parameter. The results presented here for pp breakup show excellent agreement with recent experimental data. In double Δ-isobars production in deuteron breakup, HRM angular distributions for the two double Δ channels were compared to the pn channel and to each other. An important prediction from this study is that the Δ++ Δ- channel consistently dominates Δ+Δ0, which is in contrast with models that unlike the HRM consider a double Δ system in the initial state of the interaction. For such models both channels should have the same strength.

  14. Nuclear structure and the single charge exchange

    International Nuclear Information System (INIS)

    Oset, E.; Strottman, D.

    1979-01-01

    The influence of nuclear structure on meson-induced single-charge-exchange reactions on light nuclei is discussed within the context of the Glauber approximation. Selection rules which are expected to be approximately obeyed in elastic and inelastic pion and kaon scattering are proposed. Theoretical predictions are presented for (π + ,π 0 ) and (K + ,K 0 ) reactions on 13 C. 14 figures

  15. Nuclear structure models: Applications and development

    International Nuclear Information System (INIS)

    Semmes, P.B.

    1992-07-01

    This report discusses the following topics: Studies of superdeformed States; Signature Inversion in Odd-Odd Nuclei: A fingerprint of Triaxiality; Signature Inversion in 120 Cs - Evidence for a Residual p-n Interaction; Signatures of γ Deformation in Nuclei and an Application to 125 Xe; Nuclear Spins and Moments: Fundamental Structural Information; and Electromagnetic Properties of 181 Ir: Evidence of β Stretching

  16. Progress on nuclear modifications of structure functions

    Directory of Open Access Journals (Sweden)

    Kumano S.

    2016-01-01

    Full Text Available We report progress on nuclear structure functions, especially on their nuclear modifications and a new tensor structure function for the deuteron. To understand nuclear structure functions is an important step toward describing nuclei and QCD matters from low to high densities and from low to high energies in terms of fundamental quark and gluon degrees of freedom beyond conventional hadron and nuclear physics. It is also practically important for understanding new phenomena in high-energy heavy-ion collisions at RHIC and LHC. Furthermore, since systematic errors of current neutrinooscillation experiments are dominated by uncertainties of neutrino-nucleus interactions, such studies are valuable for finding new physics beyond current framework. Next, a new tensor-polarized structure function b1 is discussed for the deuteron. There was a measurement by HERMES; however, its data are inconsistent with the conventional convolution estimate based on the standard deuteron model with D-state admixture. This fact suggests that a new hadronic phenomenon should exist in the tensor-polarized deuteron at high energies, and it will be experimentally investigated at JLab from the end of 2010’s.

  17. High performance structural ceramics for nuclear industry

    International Nuclear Information System (INIS)

    Pujari, Vimal K.; Faker, Paul

    2006-01-01

    A family of Saint-Gobain structural ceramic materials and products produced by its High performance Refractory Division is described. Over the last fifty years or so, Saint-Gobain has been a leader in developing non oxide ceramic based novel materials, processes and products for application in Nuclear, Chemical, Automotive, Defense and Mining industries

  18. Nuclear structure of Ra at high spin

    Indian Academy of Sciences (India)

    However, nuclear structure at high spin and excitation energies (∼ 6 MeV) would require a coupling of excited 1p–1h with 208Pb core. The coupling between single- particle orbitals and collective vibrations of core complicates the simple shell model picture. With increasing neutron number, Ra isotopes show an abrupt ...

  19. Nuclear structure at high excitation energies

    Indian Academy of Sciences (India)

    Study of the structure of nuclei in extreme conditions of angular momentum, excitation energy (temperature) and isospin has recently become a very interesting and active area of research in nuclear physics. Experimentally compound nuclei can be formed at high excitation energies and in high angular momentum states ...

  20. Pion double charge exchange and nuclear structure

    International Nuclear Information System (INIS)

    Ginocchio, J.N.

    1987-01-01

    Pion double charge exchange to both the double-analog state and the ground state is studied for medium weight nuclei. The relative cross section of these two transitions and the importance of nuclear structure as a function of pion kinetic energy is examined. 16 figs., 5 tabs

  1. Shield structure for a nuclear reactor

    International Nuclear Information System (INIS)

    Rouse, C.A.; Simnad, M.T.

    1979-01-01

    An improved nuclear reactor shield structure is described for use where there are significant amounts of fast neutron flux above an energy level of approximately 70 keV. The shield includes structural supports and neutron moderator and absorber systems. A portion at least of the neutron moderator material is magnesium oxide either alone or in combination with other moderator materials such as graphite and iron. (U.K.)

  2. Hirschegg '03: Nuclear structure and dynamics at the limits. Proceedings

    International Nuclear Information System (INIS)

    Feldmeier, H.; Knoll, J.; Noerenberg, W.; Wambach, J.

    2003-01-01

    The following topics were dealt with: Nuclear structure ans symmetries, nuclei near the drip line, halo nuclei and nuclear resonances, superheavy elements and fission, fragmentation and multifragmentation, nuclear astrophysics. (HSI)

  3. Existence of a miscibility gap in the U-Nd-O ternary system and its relationship with the HBS of irradiated nuclear fuel

    International Nuclear Information System (INIS)

    Dottavio, Giannina

    2014-01-01

    Today, the most used nuclear fuel in pressurized water reactors operating in French power plants is uranium dioxide UO 2 . Under irradiation, this ceramic undergoes many modifications, a very interesting one is the incorporation of fission products (Nd,Ce,Eu..) in the crystallographic structure of the fuel. In this thesis, we focused on the modifications of the crystallographic structures of the fuel caused by fission product incorporation. In order to achieve this objective, we conceived a plan formed by steps of increasing complexity and involving two types of materials: non irradiated nuclear fuel (U 1-y Nd y )O 2 (neodymium is the most abundant cationic fission product), and highly irradiated UO 2 fuels. Firstly, we have studied the evolution of crystallographic structure of a sample (U 1-y Nd y )O 2 during an annealing treatment. The results allowed us to confirm a previous hypothesis formulated in the group suggesting that Nd is not totally soluble in UO 2 , as traditionally considered. Instead of that, there is a miscibility gap in the ternary system U-Nd-O. Afterwards, we have characterized this miscibility gap, determining its tie-lines by means of two approaches: a) experimentally, by means of XRD measurements, to estimate the chemical composition of both phases in the biphasic samples, b) theoretically, by means of the thermodynamic assessment of the phase diagram U-Nd-O by the CALPHAD method, including for the assessment the tie-lines previously calculated for our samples, in order to determine the tie-lines for all composition and temperatures of this miscibility gap. We have also distinguished many others systems (U,L)O 2 (U,L,L')O 2 , in which 'L' means lanthanides or actinides existing in the irradiated fuel, that exhibit a miscibility gap. As a consequence, we formulated the hypothesis that a miscibility gap could also exist in the irradiated fuel, which could be, consequently, considered as a pseudo phase diagram U-PF-O (PF

  4. Investigation of Nuclear Partonic Structure. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Henry J. [Univ. of California, Berkeley, CA (United States); Engelage, J. M.

    2016-08-30

    Our research program had two primary goals during the period of this grant, to search for new and rare particles produced in high-energy nuclear collisions and to understand the internal structure of nuclear matter. We have developed electronics to pursue these goals at the Relativistic Heavy Ion Collider (RHIC) in the Solenoidal Tracker at RHIC (STAR) experiment and the AnDY experiment. Our results include discovery of the anti-hyper-triton, anti- 3Λ-barH, which opened a new branch on the chart of the nuclides, and the anti-alpha, anti- 4He, the heaviest form of anti-matter yet seen, as well as uncovering hints of gluon saturation in cold nuclear matter and observation of jets in polarized proton-proton collisions that will be used to probe orbital motion inside protons.

  5. Proceedings of the conference on nuclear structure at the limits

    International Nuclear Information System (INIS)

    1996-01-01

    This report contains the papers from the Proceedings of the Conference on Nuclear Structure at the Limits. Some of the areas covered by these papers are: nuclear deformation; nuclear decay; nuclear spectroscopy; radioactive ion beams; nuclear models; high spin states; and heavy ion reactions. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  6. Microwave dependence of subharmonic gap structure in superconducting junctions

    DEFF Research Database (Denmark)

    Sørensen, O. Hoffman; Kofoed, Bent; Pedersen, Niels Falsig

    1974-01-01

    are integers: m=1,2,3,… and n=0,1,2,…. The power dependence of the satellite structure and the microwave-assisted tunneling structure is consistent for all junctions tested with the expression Jn2(m e Vrf / h ν), where Jn(x) is the ordinary Bessel function of order n, Vrf is the amplitude of the induced...

  7. Building nuclear structures : challenges and achievements

    International Nuclear Information System (INIS)

    Gad, V.M.

    1981-01-01

    Reliability and safety are factors of prime importance in construction of civil engineering structures of nuclear facilities. There cannot be any compromise in the strength and life of the structure. This involves rigorous control of: (1) quality of materials and end products, (2) time taken for construction, (3) cost, and also continuing innovation. India has now accumulated more than three decades of experience in nuclear civil engineering and the civil engineering fraternity of India and particularly of the Department of Atomic Energy is now fully capable of designing and construction of all types of structures involved in the nuclear field. Illustrative examples are given. Dome of the CIRUS reactor was constructed in steel plates, but then there was a switch over to reinforced concrete for containment structures and subsequently to prestressed concrete. The aspects taken into consideration of the design to ensure absolute leak tightness are: (1) earthquake safeguards, (2) concrete surface protection, and (3) minimization of cracking in concrete due to pressure loading and shrinkage. Coordination charts are prepared for monitoring time required for various operations and time and motion studies are employed to cut down on construction time. Close control over the cost is kept through internal and external audit, executing the work departmentally or employing an outside agency as the occasion demands and proper selection of materials. Some of the innovations in materials use and construction techniques are mentioned. (K.M.)

  8. Multi-cavity locally resonant structure with the low frequency and broad band-gaps

    Directory of Open Access Journals (Sweden)

    Jiulong Jiang

    2016-11-01

    Full Text Available A multi-cavity periodic structure with the characteristic of local resonance was proposed in the paper. The low frequency band-gap structure was comparatively analyzed by the finite element method (FEM and electric circuit analogy (ECA. Low frequency band-gap can be opened through the dual influence of the coupling’s resonance in the cavity and the interaction among the couplings between structures. Finally, the influence of the structural factors on the band-gap was analyzed. The results show that the structure, which is divided into three parts equally, has a broader effective band-gap below the frequency of 200 Hz. It is also proved that reducing the interval between unit structures can increase the intensity of the couplings among the structures. And in this way, the width of band-gap would be expanded significantly. Through the parameters adjustment, the structure enjoys a satisfied sound insulation effect below the frequency of 500Hz. In the area of low frequency noise reduction, the structure has a lot of potential applications.

  9. Prestressed concrete structures for nuclear power generation

    International Nuclear Information System (INIS)

    Funabashi, Isao; Ichikawa, Kazuo.

    1981-01-01

    Prestressed concrete containment vessels are about to be adopted for power reactors, and many informations have been seen recently in newspapers and technical magazines in Japan. But prestressed concrete structures have never been used in nuclear power stations in Japan. The first nuclear power plant which will use a prestressed concrete containment vessel is the Tsuruga No. 2 plant of Japan Atomic Power Co., which is a PWR plant with 1100 MW capacity. This project is in the stage of the safety deliberation by the government as of October, 1980, and if the construction of a PCCV must be started in near future, the experiences in foreign countries are indispensable for reference. Accordingly, the construction engineers and PC engineers must prepare the related technologies steadily for enabling to meet to the expectation of the users and society, and establish the construction techniques as early as possible. The tendency of constructing nuclear facilities, the kinds of power reactors, the features in the design of nuclear reactor buildings and the application of prestressed concrete construction method are described. The prestressed concrete construction method enables to rationalize the stress condition in concrete structures, to reduce the weight, to extend the span and to upgrade the material quality, thus the applications are expanded. (Kako, I.)

  10. Two-dimensional microwave band-gap structures of different ...

    Indian Academy of Sciences (India)

    - stant and/or magnetic permeability (or in particular impedance) are periodic and the propagation of electromagnetic waves is forbidden at certain frequencies when allowed to pass through these structures. This is similar to the electronic band.

  11. Formaldehyde cross-linking and structural proteomics: Bridging the gap.

    Science.gov (United States)

    Srinivasa, Savita; Ding, Xuan; Kast, Juergen

    2015-11-01

    Proteins are dynamic entities constantly moving and altering their structures based on their functions and interactions inside and outside the cell. Formaldehyde cross-linking combined with mass spectrometry can accurately capture interactions of these rapidly changing biomolecules while maintaining their physiological surroundings. Even with its numerous established uses in biology and compatibility with mass spectrometry, formaldehyde has not yet been applied in structural proteomics. However, formaldehyde cross-linking is moving toward analyzing tertiary structure, which conventional cross-linkers have already accomplished. The purpose of this review is to describe the potential of formaldehyde cross-linking in structural proteomics by highlighting its applications, characteristics and current status in the field. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. 15th National Conference on Nuclear Structure in China

    CERN Document Server

    Wang, Ning; Zhou, Shan-Gui; Nuclear Structure in China 2014; NSC2014

    2016-01-01

    This volume is a collection of the contributions to the 15th National Conference on Nuclear Structure in China (NSC2014), held on October 25-28, 2014 in Guilin, China and hosted by Guangxi Normal University. It provides an important updated resource in the nuclear physics literature for researchers and graduate students studying nuclear structure and related topics. Recent progress made in the study of nuclear spectroscopy of high-spin states, nuclear mass and half-life, nuclear astrophysics, super-heavy nuclei, unstable nuclei, density functional theory, neutron star and symmetry energy, nuclear matter, and nuclear shell model are covered.

  13. Structure modeling and mutational analysis of gap junction beta 2 ...

    African Journals Online (AJOL)

    Therefore, a 3D structure of GJB2 was developed using comparative modeling approach. For modeling, a template was selected by blastp at NCBI and the best template selected was 2ZW3. By comparing the template-target sequence, a model was created using MODELLER, a program for homology modeling.

  14. From Informal Strategies to Structured Procedures: Mind the Gap!

    Science.gov (United States)

    Anghileri, Julia; Beishuizen, Meindert; Van Putten, Kees

    2002-01-01

    Explores written calculation methods for division used by pupils in England (n=276) and the Netherlands (n=259). Analyses informal strategies and identifies progression towards more structured procedures that result from different teaching approaches. Comparison of methods used shows greater success in the Dutch approach which is based on…

  15. Pile foundation of nuclear power plant structures

    International Nuclear Information System (INIS)

    Jurkiewicz, W.J.; Thomaz, E.; Rideg, P.; Girao, M.

    1978-01-01

    The subject of pile foundation used for nuclear power plant structures, considering the experience gained by the designers of the Angra Nuclear Power Plant, Units 2 and 3 in Brazil is dealt with. The general concept of the pile foundations, including types and execution of the piles, is described briefly. Then the two basic models, i.e. the static model and the dynamic one, used in the design are shown, and the pertinent design assumptions as related to the Angra project are mentioned. The criteria which established the loading capacity of the piles are discussed and the geological conditions of the Angra site are also explained briefly, justifying the reasons why pile foundations are necessary in this project. After that, the design procedures and particularly the tools - i.e. the computer programs - are described. It is noted that the relatively simple but always time consuming job of loading determination calculations can be computerized too, as it was done on this project through the computer program SEASA. The interesting aspects of soil/structure interaction, applicable to static models, are covered in detail, showing the theoretical base wich was used in the program PILMAT. Then the advantage resulting from computerizing of the job of pile reinforcement design are mentioned, describing briefly the jobs done by the two special programs PILDES and PILTAB. The point is stressed that the effort computerizing the structural design of this project was not so much due to the required accuracy of the calculations, but mainly due to the need to save on the design time, as to allow to perform the design task within the relatively tight time schedule. A conclusion can be drawn that design of pile foundations for nuclear power plant structures is a more complex task than the design of bearing type of foundation for the same structures, but that the task can be always made easier when the design process can be computerized. (Author)

  16. Nuclear Structure of N $\\simeq$ 56 Krypton Isotopes

    CERN Multimedia

    2002-01-01

    In view of the strong overlap in subject matter, the proposals IP-39 and 40 were considered together by the ISOLDE-Committee, and a combined investigation was suggested to be presented to the PSCC.\\\\ \\\\ First results on $\\beta$-decay properties of very neutron-rich Br isotopes (Z=35) indicate a rather smooth onset of deformation already below N=60 and the existence of a deformed N=56 subshell gap. This behaviour is in contrast to earlier observations of a sudden onset of strong deformations at N=60 for $ \\% Z ge $ 37 nuclei. \\\\ \\\\ We propose to study at CERN-ISOLDE nuclear structure properties of N=55 - 57 Kr isotopes from $\\beta$-decay of $^9

  17. Triple photonic band-gap structure dynamically induced in the presence of spontaneously generated coherence

    International Nuclear Information System (INIS)

    Gao Jinwei; Bao Qianqian; Wan Rengang; Cui Cuili; Wu Jinhui

    2011-01-01

    We study a cold atomic sample coherently driven into the five-level triple-Λ configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to 92% can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-Λ system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.

  18. Analysis of photonic band-gap structures in stratified medium

    DEFF Research Database (Denmark)

    Tong, Ming-Sze; Yinchao, Chen; Lu, Yilong

    2005-01-01

    in solving the Maxwell's equations numerically. It expands the temporal derivatives using the finite differences, while it adopts the Fourier transform (FT) properties to expand the spatial derivatives in Maxwell's equations. In addition, the method makes use of the chain-rule property in calculus together...... in electromagnetic and microwave applications once the Maxwell's equations are appropriately modeled. Originality/value - The method validates its values and properties through extensive studies on regular and defective 1D PBG structures in stratified medium, and it can be further extended to solving more...

  19. Inspection of Nuclear Power Plant Containment Structures

    Energy Technology Data Exchange (ETDEWEB)

    Graves, H.L.; Naus, D.J.; Norris, W.E.

    1998-12-01

    Safety-related nuclear power plant (NPP) structures are designed to withstand loadings from a number of low-probability external and interval events, such as earthquakes, tornadoes, and loss-of-coolant accidents. Loadings incurred during normal plant operation therefore generally are not significant enough to cause appreciable degradation. However, these structures are susceptible to aging by various processes depending on the operating environment and service conditions. The effects of these processes may accumulate within these structures over time to cause failure under design conditions, or lead to costly repair. In the late 1980s and early 1990s several occurrences of degradation of NPP structures were discovered at various facilities (e.g., corrosion of pressure boundary components, freeze- thaw damage of concrete, and larger than anticipated loss of prestressing force). Despite these degradation occurrences and a trend for an increasing rate of occurrence, in-service inspection of the safety-related structures continued to be performed in a somewhat cursory manner. Starting in 1991, the U.S. Nuclear Regulatory Commission (USNRC) published the first of several new requirements to help ensure that adequate in-service inspection of these structures is performed. Current regulatory in-service inspection requirements are reviewed and a summary of degradation experience presented. Nondestructive examination techniques commonly used to inspect the NPP steel and concrete structures to identify and quantify the amount of damage present are reviewed. Finally, areas where nondestructive evaluation techniques require development (i.e., inaccessible portions of the containment pressure boundary, and thick heavily reinforced concrete sections are discussed.

  20. Omnidirectional excitation of sidewall gap-plasmons in a hybrid gold-nanoparticle/aluminum-nanopore structure

    Directory of Open Access Journals (Sweden)

    Chatdanai Lumdee

    2016-06-01

    Full Text Available The gap-plasmon resonance of a gold nanoparticle inside a nanopore in an aluminum film is investigated in polarization dependent single particle microscopy and spectroscopy. Scattering and transmission measurements reveal that gap-plasmons of this structure can be excited and observed under normal incidence excitation and collection, in contrast to the more common particle-on-a-mirror structure. Correlation of numerical simulations with optical spectroscopy suggests that a local electric field enhancement factor in excess of 50 is achieved under normal incidence excitation, with a hot-spot located near the top surface of the structure. It is shown that the strong field enhancement from this sidewall gap-plasmon mode can be efficiently excited over a broad angular range. The presented plasmonic structure lends itself to implementation in low-cost, chemically stable, easily addressable biochemical sensor arrays providing large optical field enhancement factors.

  1. Gap Dynamics and Structure of Two Old-Growth Beech Forest Remnants in Slovenia

    Science.gov (United States)

    Rugani, Tihomir; Diaci, Jurij; Hladnik, David

    2013-01-01

    Context Due to a long history of intensive forest exploitation, few European beech (Fagus sylvatica L.) old-growth forests have been preserved in Europe. Material and Methods We studied two beech forest reserves in southern Slovenia. We examined the structural characteristics of the two forest reserves based on data from sample plots and complete inventory obtained from four previous forest management plans. To gain a better understanding of disturbance dynamics, we used aerial imagery to study the characteristics of canopy gaps over an 11-year period in the Kopa forest reserve and a 20-year period in the Gorjanci forest reserve. Results The results suggest that these forests are structurally heterogeneous over small spatial scales. Gap size analysis showed that gaps smaller than 500 m2 are the dominant driving force of stand development. The percentage of forest area in canopy gaps ranged from 3.2 to 4.5% in the Kopa forest reserve and from 9.1 to 10.6% in the Gorjanci forest reserve. These forests exhibit relatively high annual rates of coverage by newly established (0.15 and 0.25%) and closed (0.08 and 0.16%) canopy gaps. New gap formation is dependant on senescent trees located throughout the reserve. Conclusion We conclude that these stands are not even-sized, but rather unevenly structured. This is due to the fact that the disturbance regime is characterized by low intensity, small-scale disturbances. PMID:23308115

  2. Phononic band gaps and vibrations in one- and two-dimensional mass-spring structures

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard

    2003-01-01

    The vibrational response of finite periodic lattice structures subjected to periodic loading is investigated. Special attention is devoted to the response in frequency ranges with gaps in the band structure for the corresponding infinite periodic lattice. The effects of boundaries, viscous dampin...

  3. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1978-10-01

    This is the fourth issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation is published and distributed by the IAEA Nuclear Data Section every year. The material contained in this compilation is sorted according to eight subject categories: General compilations; basic isotopic properties; nuclear structure properties; nuclear decay processes, half-lives, energies and spectra; nuclear decay processes, gamma-rays; nuclear decay processes, fission products; nuclear decay processes (others); atomic processes

  4. Structural Transformation of Wireframe DNA Origami via DNA Polymerase Assisted Gap-Filling.

    Science.gov (United States)

    Agarwal, Nayan P; Matthies, Michael; Joffroy, Bastian; Schmidt, Thorsten L

    2018-03-27

    The programmability of DNA enables constructing nanostructures with almost any arbitrary shape, which can be decorated with many functional materials. Moreover, dynamic structures can be realized such as molecular motors and walkers. In this work, we have explored the possibility to synthesize the complementary sequences to single-stranded gap regions in the DNA origami scaffold cost effectively by a DNA polymerase rather than by a DNA synthesizer. For this purpose, four different wireframe DNA origami structures were designed to have single-stranded gap regions. This reduced the number of staple strands needed to determine the shape and size of the final structure after gap filling. For this, several DNA polymerases and single-stranded binding (SSB) proteins were tested, with T4 DNA polymerase being the best fit. The structures could be folded in as little as 6 min, and the subsequent optimized gap-filling reaction was completed in less than 3 min. The introduction of flexible gap regions results in fully collapsed or partially bent structures due to entropic spring effects. Finally, we demonstrated structural transformations of such deformed wireframe DNA origami structures with DNA polymerases including the expansion of collapsed structures and the straightening of curved tubes. We anticipate that this approach will become a powerful tool to build DNA wireframe structures more material-efficiently, and to quickly prototype and test new wireframe designs that can be expanded, rigidified, or mechanically switched. Mechanical force generation and structural transitions will enable applications in structural DNA nanotechnology, plasmonics, or single-molecule biophysics.

  5. Nuclear structure around Z=28 and N=40 investigated by the beta decay of Fe, Co and Ni isotopes.

    OpenAIRE

    Pauwels, Dieter

    2009-01-01

    Introduction Nuclei near the Z=28 closed shell gap and the N=40 closed subshell gap d raw considerable interest in current nuclear-structure investigations. A ccording to the shell model, a pronounced shell closure exists at Z=28. At N=40, a rather large energy gap exists between the p1/2 and g9/2 orbi tals, but less pronounced than the gap at Z=28. One speaks of a subshell closure at N=40. At the crossing of Z=28 and N=40 lies 68Ni, which exhibits features char acteristic for double-ma...

  6. Nuclear matrix - structure, function and pathogenesis.

    Science.gov (United States)

    Wasąg, Piotr; Lenartowski, Robert

    2016-12-20

    The nuclear matrix (NM), or nuclear skeleton, is the non-chromatin, ribonucleoproteinaceous framework that is resistant to high ionic strength buffers, nonionic detergents, and nucleolytic enzymes. The NM fulfills a structural role in eukaryotic cells and is responsible for maintaining the shape of the nucleus and the spatial organization of chromatin. Moreover, the NM participates in several cellular processes, such as DNA replication/repair, gene expression, RNA transport, cell signaling and differentiation, cell cycle regulation, apoptosis and carcinogenesis. Short nucleotide sequences called scaffold/matrix attachment regions (S/MAR) anchor the chromatin loops to the NM proteins (NMP). The NMP composition is dynamic and depends on the cell type and differentiation stage or metabolic activity. Alterations in the NMP composition affect anchoring of the S/MARs and thus alter gene expression. This review aims to systematize information about the skeletal structure of the nucleus, with particular emphasis on the organization of the NM and its role in selected cellular processes. We also discuss several diseases that are caused by aberrant NM structure or dysfunction of individual NM elements.

  7. Nuclear structure/nuclei far from stability

    International Nuclear Information System (INIS)

    Casten, R.F.; Garrett, J.D.; Moller, P.; Bauer, W.W.; Brenner, D.S.; Butler, G.W.; Crawford, J.E.; Davids, C.N.; Dyer, P.L.; Gregorich, K.; Hagbert, E.G.; Hamilton, W.D.; Harar, S.; Haustein, P.E.; Hayes, A.C.; Hoffman, D.C.; Hsu, H.H.; Madland, D.G.; Myers, W.D.; Penttila, H.T.; Ragnarsson, I.; Reeder, P.L.; Robertson, G.H.; Rowley, N.; Schreiber, F.; Seifert, H.L.; Sherrill, B.M.; Siciliano, E.R.; Sprouse, G.D.; Stephens, F.S.; Subotic, K.; Talbert, W.; Toth, K.S.; Tu, X.L.; Vieira, D.J.; Villari, A.C.C.; Walters, W.B.; Wildenthal, B.H.; Wilhelmy, J.B.; Winger, J.A.; Wohn, F.K.; Wouters, J.M.; Zhou, X.G.; Zhou, Z.Y.

    1990-01-01

    This report outlines some of the nuclear structure topics discussed at the Los Alamos Workshop on the Science of Intense Radioactive Ion Beams (RIB). In it we also tried to convey some of the excitement of the participants for utilizing RIBs in their future research. The introduction of radioactive beams promises to be a major milestone for nuclear structure perhaps even more important than the last such advance in beams based on the advent of heavy-ion accelerators in the 1960's. RIBs not only will allow a vast number of new nuclei to be studies at the extremes of isospin, but the variety of combinations of exotic proton and neutron configurations should lead to entirely new phenomena. A number of these intriguing new studies and the profound consequences that they promise for understanding the structure of the atomic nucleus, nature's only many-body, strongly-inteacting quantum system, are discussed in the preceeding sections. However, as with any scientific frontier, the most interesting phenomena probably will be those that are not anticipated--they will be truly new

  8. Evaluation of communication structures for nuclear-specific applications

    International Nuclear Information System (INIS)

    Zahedi, P.

    2007-01-01

    This paper evaluates various implementations of communication structures associated with nuclear-specific applications. Establishing numerous network structures currently used in nuclear industry, this projects analyzes the functionality and reliability of different structures. The communication structures studied in this paper include Object Linking and Embedding process control (OPC), Dynamic Data Exchange (DDE) and Modbus Communication Protocol. The experimental aspect of this project includes development and implementation of each network structure for NPP control and shutdown systems. The results of the experimentations are used to identify the potential problems of applying such structures to nuclear industry, in order to introduce nuclear-specific network structures. (author)

  9. Research on the Band Gap Characteristics of Two-Dimensional Phononic Crystals Microcavity with Local Resonant Structure

    Directory of Open Access Journals (Sweden)

    Mao Liu

    2015-01-01

    Full Text Available A new two-dimensional locally resonant phononic crystal with microcavity structure is proposed. The acoustic wave band gap characteristics of this new structure are studied using finite element method. At the same time, the corresponding displacement eigenmodes of the band edges of the lowest band gap and the transmission spectrum are calculated. The results proved that phononic crystals with microcavity structure exhibited complete band gaps in low-frequency range. The eigenfrequency of the lower edge of the first gap is lower than no microcavity structure. However, for no microcavity structure type of quadrilateral phononic crystal plate, the second band gap disappeared and the frequency range of the first band gap is relatively narrow. The main reason for appearing low-frequency band gaps is that the proposed phononic crystal introduced the local resonant microcavity structure. This study provides a good support for engineering application such as low-frequency vibration attenuation and noise control.

  10. Chiral nucleon-nucleon forces in nuclear structure calculations

    Directory of Open Access Journals (Sweden)

    Coraggio L.

    2016-01-01

    Full Text Available Realistic nuclear potentials, derived within chiral perturbation theory, are a major breakthrough in modern nuclear structure theory, since they provide a direct link between nuclear physics and its underlying theory, namely the QCD. As a matter of fact, chiral potentials are tailored on the low-energy regime of nuclear structure physics, and chiral perturbation theory provides on the same footing two-nucleon forces as well as many-body ones. This feature fits well with modern advances in ab-initio methods and realistic shell-model. Here, we will review recent nuclear structure calculations, based on realistic chiral potentials, for both finite nuclei and infinite nuclear matter.

  11. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    1991-01-01

    The past year has seen continued progress in our efforts. On the experimental side, we completed data acquisition on our major remaining involvement at NIKHEF, the 12 C(e,e'pp) experiment. We advanced the analysis of most of projects in low lying nuclear structure and giant resonances, of which several were completed and published. We received approval for several new experiments, and have made major contributions to design and development of detectors to be used at Bates and CEBAF. Our data interpretation efforts have been extended and enhanced with the availability of our new computer cluster. In this paper we briefly report on most of these efforts

  12. Detailed nuclear structure studies far from stability

    International Nuclear Information System (INIS)

    Wood, J.L.; Schwarzenberg, J.; Zganjar, E.F.; Rupnik, D.

    1991-01-01

    State-of--the-art spectroscopy of nuclei far from stability has achieved an extraordinary level of sophistication and detail in the last ten years. In principle, if a state can be populated, it can be characterized by its energy, spin, parity, and major decay paths. Sometimes its lifetime can be measured. In practice, one is confronted with enormous complexity. To convert raw spectroscopic data into nuclear structure data involves a complex process of disentangling gamma rays and conversion electrons into decay schemes. Specifically, coincidence techniques, especially coincidence intensities, play a crucial role in this process. Recent examples and methods from work done at UNISOR are presented

  13. ENSL and CDRL: Evaluated nuclear structure libraries

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1981-01-01

    Two files of nuclear structure data derived largely from the seventh edition of the Table of Isotopes are described. The files are computer oriented, and have been constructed to so that every decay can be traced either to an eventual ground state of to a positive flag that indicates nothing is known about further decay. The ENSL file contains level schemes derived from decay data, and the CDRL file contains the level schemes derived from particle-induced reaction data that have been merged into the ENSL file. (author)

  14. Tungsten - Yttrium Based Nuclear Structural Materials

    Science.gov (United States)

    Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

    2013-04-01

    The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

  15. Aging management of nuclear fuel pool structures

    International Nuclear Information System (INIS)

    Hookham, C.J.

    1991-01-01

    The long-term operations of a nuclear power plant (NPP) are currently impacted by the utility's capabilities with respect to spent fuel storage. Available options for the safe, long-term storage of spent fuel are quite limited; as such, maximized usage of existing on-site storage capacity (NPP) is quite important. The service life of existing fuel pool structures may be determined by a number of operations or age-related events. Management of these events is often critical to the structure's integrity and durability. From an operations vantage point, aging management relates to such characteristics as storage capacity, performance of pool water treatment systems, and physical liner damage. Primary issues related to structural integrity include materials degradation and environmental enclosure factors. The development of an effective aging management program should address both operational and structural issues. The goal of this paper is to provide recommendations for pool structure aging management, with benefits to both short and long-term, or extended life, operations. Because of their critical nature, the report will focus on spent fuel pools. Many of the concepts generated in this report may also be applied to other NPP pool structures (i.e., new fuel pools, reactor internals pits and transfer canals) because of similar physical/environmental effects

  16. Effects of weak nonlinearity on dispersion relations and frequency band-gaps of periodic structures

    DEFF Research Database (Denmark)

    Sorokin, Vladislav; Thomsen, Jon Juel

    2015-01-01

    The analysis of the behaviour of linear periodic structures can be traced back over 300 years, to Sir Isaac Newton, and still attracts much attention. An essential feature of periodic struc-tures is the presence of frequency band-gaps, i.e. frequency ranges in which waves cannot propagate....... Determination of band-gaps and the corresponding attenuation levels is an im-portant practical problem. Most existing analytical methods in the field are based on Floquet theory; e.g. this holds for the classical Hill’s method of infinite determinants, and the method of space-harmonics. However, application....... The present work deals with analytically predicting dynamic responses for nonlinear continuous elastic periodic structures. Specifically, the effects of weak nonlinearity on the dispersion re-lation and frequency band-gaps of a periodic Bernoulli-Euler beam performing bending os-cillations are analyzed...

  17. Interventions aimed at closing the social class achievement gap: changing individuals, structures, and construals.

    Science.gov (United States)

    Dittmann, Andrea G; Stephens, Nicole M

    2017-12-01

    Understanding the sources of the social class achievement gap in education is an important step toward ensuring that education serves its purpose as an engine of social mobility. The goal of the current article is to provide a brief overview of the sources of the social class achievement gap as well as interventions aimed at closing this gap. We outline three major sources of the social class achievement gap-individual skills, structural conditions, and people's processes of meaning-making, or construals-and the interventions that target them. While all of these interventions can effect change, we propose that interventions will be most effective when tailored to fit the specific needs of students and the context in which they are delivered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Experience in ultrasonic gap measurement between calandria tubes and liquid injection shutdown systems nozzles in Bruce Nuclear Generating Station

    International Nuclear Information System (INIS)

    Abucay, R.C.; Mahil, K.S.; Goszczynski, J.J.

    1995-01-01

    The gaps between calandria tubes (CT) and Liquid Injection Shutdown System (LISS) nozzles at the Bruce Nuclear Generating Station ''A'' (Bruce A) are known to decrease with time due to radiation induced creep/sag of the calandria tubes. If this gap decreases to a point where the calandria tubes come into contact with the LISS nozzle, the calandria tubes could fail as a result of fretting damage. Proximity measurements were needed to verify the analytical models and ensure that CT/LISS nozzle contact does not occur earlier than predicted. The technique used was originally developed at Ontario Hydro Technologies (formerly Ontario Hydro Research Division) in the late seventies and put into practical use by Research and Productivity Council (RPC) of New Brunswick, who carried out similar measurements at Point Lepreau NGS in 1989 and 1991. The gap measurement was accomplished y inserting an inspection probe, containing four ultrasonic transducers (2 to measure gaps and 2 to check for probe tilt) and a Fredericks electrolytic potentiometer as a probe rotational sensor, inside LISS Nozzle number-sign 7. The ultrasonic measurements were fed to a system computer that was programmed to convert the readings into fully compensated gaps, taking into account moderator heavy water temperature and probe tilt. Since the measured gaps were found to be generally larger than predicted, the time to CT/LISS nozzle contact is now being re-evaluated and the planned LISS nozzle replacement will likely be deferred, resulting in considerable savings

  19. Development of analysis methods for seismically isolated nuclear structures

    International Nuclear Information System (INIS)

    Yoo, Bong; Lee, Jae-Han; Koo, Gyeng-Hoi

    2002-01-01

    KAERI's contributions to the project entitled Development of Analysis Methods for Seismically Isolated Nuclear Structures under IAEA CRP of the intercomparison of analysis methods for predicting the behaviour of seismically isolated nuclear structures during 1996-1999 in effort to develop the numerical analysis methods and to compare the analysis results with the benchmark test results of seismic isolation bearings and isolated nuclear structures provided by participating countries are briefly described. Certain progress in the analysis procedures for isolation bearings and isolated nuclear structures has been made throughout the IAEA CRPs and the analysis methods developed can be improved for future nuclear facility applications. (author)

  20. Update on nuclear structure effects in light muonic atoms

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Oscar Javier, E-mail: javierh@triumf.ca; Dinur, Nir Nevo; Ji, Chen; Bacca, Sonia [TRIUMF (Canada); Barnea, Nir [The Hebrew University, Racah Institute of Physics (Israel)

    2016-12-15

    We present calculations of the nuclear structure corrections to the Lamb shift in light muonic atoms, using state-of-the-art nuclear potentials. We outline updated results on finite nucleon size contributions.

  1. International conference: Features of nuclear excitation states and mechanisms of nuclear reactions. 51. Meeting on nuclear spectroscopy and nuclear structure. The book of abstracts

    International Nuclear Information System (INIS)

    2001-01-01

    Results of the LI Meeting on Nuclear Spectroscopy and Nuclear Structure are presented. Properties of excited states of atomic nuclei and mechanisms of nuclear reactions are considered. Studies on the theory of nucleus and fundamental interactions pertinent to experimental study of nuclei properties and mechanisms of nuclear reactions, technique and methods of experiment, application of nuclear-physical method, are provided [ru

  2. The Development of Layered Photonic Band Gap Structures Using a Micro-Transfer Molding Technique

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, Kevin Jerome [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Photonic band gap (PBG) crystals are periodic dielectric structures that manipulate electromagnetic radiation in a manner similar to semiconductor devices manipulating electrons. Whereas a semiconductor material exhibits an electronic band gap in which electrons cannot exist, similarly, a photonic crystal containing a photonic band gap does not allow the propagation of specific frequencies of electromagnetic radiation. This phenomenon results from the destructive Bragg diffraction interference that a wave propagating at a specific frequency will experience because of the periodic change in dielectric permitivity. This gives rise to a variety of optical applications for improving the efficiency and effectiveness of opto-electronic devices. These applications are reviewed later. Several methods are currently used to fabricate photonic crystals, which are also discussed in detail. This research involves a layer-by-layer micro-transfer molding ({mu}TM) and stacking method to create three-dimensional FCC structures of epoxy or titania. The structures, once reduced significantly in size can be infiltrated with an organic gain media and stacked on a semiconductor to improve the efficiency of an electronically pumped light-emitting diode. Photonic band gap structures have been proven to effectively create a band gap for certain frequencies of electro-magnetic radiation in the microwave and near-infrared ranges. The objective of this research project was originally two-fold: to fabricate a three dimensional (3-D) structure of a size scaled to prohibit electromagnetic propagation within the visible wavelength range, and then to characterize that structure using laser dye emission spectra. As a master mold has not yet been developed for the micro transfer molding technique in the visible range, the research was limited to scaling down the length scale as much as possible with the current available technology and characterizing these structures with other methods.

  3. Nuclear Structure Near the Drip Lines

    International Nuclear Information System (INIS)

    Nazarewicz, W.

    1998-01-01

    Experiments with beams of unstable nuclei will make it possible to look closely into many aspects of the nuclear many-body problem. Theoretically, exotic nuclei represent a formidable challenge for the nuclear many-body theories and their power to predict nuclear properties in nuclear terra incognita

  4. Estimation of photonic band gap in the hollow core cylindrical multilayer structure

    Science.gov (United States)

    Chourasia, Ritesh Kumar; Singh, Vivek

    2018-04-01

    The propagation characteristic of two hollow core cylindrical multilayer structures having high and low refractive index contrast of cladding regions have been studied and compared at two design wavelengths i.e. 1550 nm and 632.8 nm. With the help of transfer matrix method a relation between the incoming light wave and outgoing light wave has been developed using the boundary matching technique. In high refractive index contrast, small numbers of layers are sufficient to provide perfect band gap in both design wavelengths. The spectral position and width of band gap is highly depending on the optical path of incident light in all considered cases. For sensing application, the sensitivity of waveguide can be obtained either by monitoring the width of photonic band gap or by monitoring the spectral shift of photonic band gap. Change in the width of photonic band gap with the core refractive index is larger in high refractive index contrast of cladding materials. However, in the case of monitoring the spectral shift of band gap, the obtained sensitivity is large for low refractive index contrast of cladding materials and further it increases with increase of design wavelength.

  5. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1977-03-01

    This is the second issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation of compilations and evaluations is designed to keep the nuclear scientific community informed of the availability of compiled or evaluated NSD data, and contains references to laboratory reports, journal articles and books containing selected compilations and evaluations. It excludes references to ''mass-chain'' evaluations normally published in the ''Nuclear Data Sheets'' and ''Nuclear Physics''. The material contained in this compilation is sorted according to eight subject categories: general compilations; basic isotopic properties; nuclear structure properties; nuclear decay processes; half-lives, energies and spectra; nuclear decay processes: gamma-rays; nuclear decay processes: fission products; nuclear decay processes: (others); atomic processes

  6. Gap junctions in cells of the immune system: structure, regulation and possible functional roles

    Directory of Open Access Journals (Sweden)

    J.C. Sáez

    2000-04-01

    Full Text Available Gap junction channels are sites of cytoplasmic communication between contacting cells. In vertebrates, they consist of protein subunits denoted connexins (Cxs which are encoded by a gene family. According to their Cx composition, gap junction channels show different gating and permeability properties that define which ions and small molecules permeate them. Differences in Cx primary sequences suggest that channels composed of different Cxs are regulated differentially by intracellular pathways under specific physiological conditions. Functional roles of gap junction channels could be defined by the relative importance of permeant substances, resulting in coordination of electrical and/or metabolic cellular responses. Cells of the native and specific immune systems establish transient homo- and heterocellular contacts at various steps of the immune response. Morphological and functional studies reported during the last three decades have revealed that many intercellular contacts between cells in the immune response present gap junctions or "gap junction-like" structures. Partial characterization of the molecular composition of some of these plasma membrane structures and regulatory mechanisms that control them have been published recently. Studies designed to elucidate their physiological roles suggest that they might permit coordination of cellular events which favor the effective and timely response of the immune system.

  7. Webb Model of Nuclear Structure and Forces

    Science.gov (United States)

    Webb, Bill

    2008-10-01

    String theory has established that neutrons and protons consist of threesomes of string-like quarks. These threesomes nucleosynthesize to build larger nuclei. This Webb Model differs by postulating that the larger nuclei are also threesomes: threesomes of string-like ring shaped Jumbo Quarks. A threesome of Jumbo Quarks make up every larger nucleus. From this starting point, the Webb Model uses only the forces of gravity and electromagnetics to accurately calculate a large variety of nuclear properties including - fundamental structural shapes and charge arrangements - the size, shape, internal forces and relativistic mass energies of the neutron, proton, deuteron, triton, alpha particle and oxygen - the details of all types of beta decay - the correct slope of the lower end of the nuclear chart - the calculated stability of the 45 smallest stable nuclei and their 59 naturally occurring unstable isotopes - and mathematical confirmation of the magic number 2,8 and 20. This Webb model satisfies the empirical tests of the Scientific Method. The mathematics is simple enough to be confirmed by any scientist without bias.

  8. Nuclear structure research. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1996-01-01

    The most significant development this year has been the realization that EO transition strength is a fundamental manifestation of nuclear mean-square charge radius differences. Thus, EO transitions provide a fundamental signature for shape coexistence in nuclei. In this sense, EO transitions are second only to E2 transitions for signaling (quadrupole) shapes in nuclei and do so when shape differences occur. A major effort has been devoted to the review of EO transitions in nuclei. Experiments have been carried out or are scheduled at: ATLAS/FMA (α decay of very neutron-deficient Bi isotopes); MSU/NSCL (β decay of 56 Cu); and HRIBF/RMS (commissioning of tape collector, internal conversion/internal-pair spectrometer; β decay of 58 Cu). A considerable effort has been devoted to planning the nuclear structure physics that will be pursued using HRIBF. Theoretical investigations have continued in collaboration with Prof. K. Heyde, Prof. D.J. Rowe, Prof. J.O. Rasmussen, and Prof. P.B. Semmes. These studies focus on shape coexistence and particle-core coupling

  9. Beyond Popular Cultural and Structural Arguments: Imagining a Compass to Guide Burgeoning Urban Achievement Gap Scholars

    Science.gov (United States)

    Hughes, Sherick A.; North, Connie E.

    2012-01-01

    This manuscript begins by distinguishing the common structural and cultural arguments that tend to guide popular urban achievement gap research. It highlights Jencks and Phillips, and Payne, as two cases of popular texts followed by critical responses to them. It concludes by imagining a compass to guide burgeoning scholars toward reading into…

  10. Aging of nuclear safety related concrete structures

    International Nuclear Information System (INIS)

    Cerny, R.; Vydra, V.; Toman, J.; Vodak, F.

    1994-01-01

    An analysis of aging processes in nuclear-safety-related concrete structures (NSRCS) is presented. The major environmental stressor and aging factors affecting the performance of NSRCS are summarized, as are drying and plastic shrinkage, expansion of water during the freeze-thaw cycle, water passing through cracks dissolving or leaching the soluble calcium hydroxide, attack of acid rain and ground water, chemical reactions between particular aggregates and the alkaline solution within cement paste, reaction of calcium hydroxide in cement paste hydration products with atmospheric carbon dioxide, and physical radiation effects of neutrons and gamma radiation. The current methods for aging management in NSRCS are analyzed and evaluated. A new treatment is presented for the monitoring, evaluation and prediction of aging processes, consisting in a combination of theoretical methods, laboratory experiments, in-situ measurements and numerical simulations. 24 refs

  11. Creation And App Lication Of A Generative Algorithm Fo R Designing Rod Gap Steel Structures

    Directory of Open Access Journals (Sweden)

    Vytautas Pliadis

    2013-12-01

    Full Text Available Designing an attractive and structurally rational architecturalform is a complex process that consists of the consequent stagesof design and selection of the final rational solution. The applicationof modern information technology based on buildinginformation modelling assists with facilitating and speeding upthe introduced process. Building Information Models (BIM isdeveloped using a parametric interface the structure of which isbased on a generative algorithm – a tool for replicating the evolutionof a particular structure thus finding the best solution. Thepaper presents the process of creating and applying the generativealgorithm for the interactive model of the rod gap structure anddisplays the results of the carried out analysis.

  12. Nuclear structure and radioactive decay resources at the US National Nuclear Data Center

    International Nuclear Information System (INIS)

    Sonzogni, A.A.; Burrows, T.W.; Pritychenko, B.; Tuli, J.K.; Winchell, D.F.

    2008-01-01

    The National Nuclear Data Center has a long tradition of evaluating nuclear structure and decay data as well as offering tools to assist in nuclear science research and applications. With these tools, users can obtain recommended values for nuclear structure and radioactive decay observables as well as links to the relevant articles. The main databases or tools are ENSDF, NSR, NuDat and the new Endf decay data library. The Evaluated Nuclear Structure Data File (ENSDF) stores recommended nuclear structure and decay data for all nuclei. ENSDF deals with properties such as: -) nuclear level energies, spin and parity, half-life and decay modes, -) nuclear radiation energy and intensity for different types, -) nuclear decay modes and their probabilities. The Nuclear Science References (NSR) is a bibliographic database containing nearly 200.000 nuclear sciences articles indexed according to content. About 4000 are added each year covering 80 journals as well as conference proceedings and laboratory reports. NuDat is a software product with 2 main goals, to present nuclear structure and decay information from ENSDF in a user-friendly way and to allow users to execute complex search operations in the wealth of data contained in ENSDF. The recently released Endf-B7.0 contains a decay data sub-library which has been derived from ENSDF. The way all these databases and tools have been offered to the public has undergone a drastic improvement due to advancements in information technology

  13. Nuclear power plants: structure and function

    International Nuclear Information System (INIS)

    Hendrie, J.M.

    1983-01-01

    Topics discussed include: steam electric plants; BWR type reactors; PWR type reactors; thermal efficiency of light water reactors; other types of nuclear power plants; the fission process and nuclear fuel; fission products and reactor afterheat; and reactor safety

  14. [Studies of nuclear structure using neutrons and charged particles

    International Nuclear Information System (INIS)

    1989-01-01

    This report contains brief discussions on nuclear research done at Triangle Universities Nuclear Laboratory. The major categories covered are: Fundamental symmetries in the nucleus; Dynamics in very light nuclei; D states in light nuclei; Nucleon-nucleus interactions; Nuclear structure and reactions; and Instrumentation and development

  15. Nuclear Cartography: Patterns in Binding Energies and Subatomic Structure

    Science.gov (United States)

    Simpson, E. C.; Shelley, M.

    2017-01-01

    Nuclear masses and binding energies are some of the first nuclear properties met in high school physics, and can be used to introduce radioactive decays, fusion, and fission. With relatively little extension, they can also illustrate fundamental concepts in nuclear physics, such as shell structure and pairing, and to discuss how the elements…

  16. Tornado-resistance design for the nuclear safety structure of Qinshan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Xia Zufeng.

    1987-01-01

    The primary design consideration of anti-tornado of the nuclear safety structure of Qinshan Nuclear Power Plant is briefly presented. It mainly includes estimating the probability of tornado arising in the site, ascertaining the design requirments of the anti-tornado structures and deciding the tornado load acted on the structures

  17. Reducing support loss in micromechanical ring resonators using phononic band-gap structures

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Feng-Chia; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin [Industrial Technology Research Institute-South, Tainan 709, Taiwan (China); Hsu, Jin-Chen, E-mail: fengchiahsu@itri.org.t, E-mail: hsujc@yuntech.edu.t [Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan (China)

    2011-09-21

    In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.

  18. Aging of concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Pland, C.B.; Arndt, E.G.

    1991-01-01

    The Structural Aging (SAG) Program, sponsored by the US Nuclear Regulatory Commission (USNRC) and conducted by the Oak Ridge National Laboratory (ORNL), had the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant structures for continued service. The program consists of three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued service determinations. Major accomplishments under the SAG Program during the first two years of its planned five-year duration have included: development of a Structural Materials Information Center and formulation of a Structural Aging Assessment Methodology for Concrete Structures in Nuclear Power Plants. 9 refs

  19. Surface plasmon polariton band gap structures: implications to integrated plasmonic circuits

    DEFF Research Database (Denmark)

    Bozhevolnyi, S. I.; Volkov, V. S.; Østergaard, John Erland

    2001-01-01

    Conventional photonic band gap (PBG) structures are composed of regions with periodic modulation of refractive index that do not allow the propagation of electromagnetic waves in a certain interval of wavelengths, i.e., that exhibit the PBG effect. The PBG effect is essentially an interference...... phenomenon related to strong multiple scattering of light in periodic media. The interest to the PBG structures has dramatically risen since the possibility of efficient waveguiding around a sharp corner of a line defect in the PBG structure has been pointed out. Given the perspective of integrating various...... PBG-based components within a few hundred micrometers, we realized that other two-dimensional waves, e.g., surface plasmon polaritons (SPPs), might be employed for the same purpose. The SPP band gap (SPPBG) has been observed for the textured silver surfaces by performing angular measurements...

  20. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1990-01-01

    This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP).

  1. Structural analysis, electronic properties, and band gaps of a graphene nanoribbon: A new 2D materials

    Science.gov (United States)

    Dass, Devi

    2018-03-01

    Graphene nanoribbon (GNR), a new 2D carbon nanomaterial, has some unique features and special properties that offer a great potential for interconnect, nanoelectronic devices, optoelectronics, and nanophotonics. This paper reports the structural analysis, electronic properties, and band gaps of a GNR considering different chirality combinations obtained using the pz orbital tight binding model. In structural analysis, the analytical expressions for GNRs have been developed and verified using the simulation for the first time. It has been found that the total number of unit cells and carbon atoms within an overall unit cell and molecular structure of a GNR have been changed with the change in their chirality values which are similar to the values calculated using the developed analytical expressions thus validating both the simulation as well as analytical results. Further, the electronic band structures at different chirality values have been shown for the identification of metallic and semiconductor properties of a GNR. It has been concluded that all zigzag edge GNRs are metallic with very small band gaps range whereas all armchair GNRs show both the metallic and semiconductor nature with very small and high band gaps range. Again, the total number of subbands in each electronic band structure is equal to the total number of carbon atoms present in overall unit cell of the corresponding GNR. The semiconductors GNRs can be used as a channel material in field effect transistor suitable for advanced CMOS technology whereas the metallic GNRs could be used for interconnect.

  2. Analysis of photonic band-gap (PBG) structures using the FDTD method

    DEFF Research Database (Denmark)

    Tong, M.S.; Cheng, M.; Lu, Y.L.

    2004-01-01

    In this paper, a number of photonic band-gap (PBG) structures, which are formed by periodic circuit elements printed oil transmission-line circuits, are studied by using a well-known numerical method, the finite-difference time-domain (FDTD) method. The results validate the band-stop filter...... behavior of these structures, and the computed results generally match well with ones published in the literature. It is also found that the FDTD method is a robust, versatile, and powerful numerical technique to perform such numerical studies. The proposed PBG filter structures may be applied in microwave...

  3. Establishment and Analysis of Nuclear Structure Data DB for Nuclear Safety Regulation Technique Applications

    International Nuclear Information System (INIS)

    Lee, Young Ouk; Yoo, Jae Kwon; Gil, Choong; Cho, Young Sik; Kim, Hyung Il; Kim, Jong Woon; Kwon, Duk Hee; Lee, Jong Hwa

    2013-10-01

    The contents of the project consisting of four research fields carried out are: Ο Installation of DB with nuclear structure/decay datasets - Setup a computer system for production of nuclear structure/decay data in ENSDF format - Production of nuclear structure/decay data in ENSDF format( 211 , 215 Po, 136 Cs) and setup a data converting system from ENSDF format to ENDF-6 format. Ο Computer simulation of nuclear decay and burnup using the ENSDF DB - Calculation of decay heats of the several radioactive nuclides with Geant4 - Burnup calculation with full decay chain using Monte Carlo method Ο Comparison and analysis of nuclear structure/decay and fission product yields data. - Acquisitions and Analyses of decay and fission yields data in ENDF-6 format - Research for theoretical evaluation method of fission product yields data. Ο Analysis of SCALE(ORIGEN-s, -ARP) libraries - Analysis of ORIGEN library structure of nuclear decay/yields data. - Methodological studies to improve nuclear decay/yield ORIGEN libraries by use of nuclear structure/yield data in ENDF-6 format. The results of this project will be a basis to establish the nuclear decay and fission yield data DB in Korea. Additionally, new decay and yield data can be immediately served for the users to utilize those data for nuclear research and/or development

  4. Nuclear data newsletter. No. 20. Nuclear structure and decay data network

    International Nuclear Information System (INIS)

    1994-11-01

    This special issue of the Nuclear Data Newsletter dated November 1994 gives information on the Nuclear Structure and Decay Data (NSDD) Network established in 1974 under the auspices of the IAEA and comprising 17 laboratories and universities in 10 countries. The procedures for online access to US National Nuclear Data Center, NEA Data Bank in Paris and IAEA Nuclear Data Section in Vienna are presented

  5. Proceedings of second national workshop on nuclear structure physics

    International Nuclear Information System (INIS)

    Chintalapudi, S.N.; Jain, A.K.

    1995-01-01

    The Second National Workshop on Nuclear Structure Physics was held at Calcutta during February 7-10 1995. The topics discussed have been quite broad based and covered many areas of nuclear structure physics and radiochemistry. Papers relevant to INIS are indexed separately

  6. Threedimensional imaging of organ structures by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Waters, W.; Smolorz, J.; Wellner, U.

    1985-01-01

    A simple method for threedimensional imaging of organ structures is presented. The method is based on a special acquisition mode in a nuclear resonance tomograph, exciting layers of 20 cm thickness at different angulations. The display is done by cinematography (which is usually used in nuclear cardiology) projecting the structures in a rotating movement. (orig.) [de

  7. Nuclear Structure References (NSR) file. [Mostly information for input

    Energy Technology Data Exchange (ETDEWEB)

    Ewbank, W.B.

    1978-08-01

    The use of the Nuclear Structure References file by the Nuclear Data Project at ORNL is described. Much of the report concerns format information of interest only to those preparing input to the system or otherwise needing detailed knowledge of its internal structure. 17 figures. (RWR)

  8. Gap structure of iron-pnictide superconductors from low-temperature heat transport

    Science.gov (United States)

    Reid, Jean-Philippe

    2010-03-01

    The structure of the superconducting gap provides important clues on the symmetry of the order parameter and the pairing mechanism. Here I describe how measurements of the thermal conductivity at very low temperature can be used to determine whether nodes are present in the gap function of a particular superconductor, and how the application of a magnetic field probes the low-energy quasiparticle excitations. Measurements on hole-doped and electron-doped pnictide superconductors, Ba1-xKxFe2As2 [1] and Ba(Fe1-xCox)2As2 [2], reveal a negligible residual linear term at T->0, showing that the gap of these two superconductors has no nodes, at least in the basal plane. In both pnictides, a small field is found to be very effective in exciting quasiparticles, showing that the gap must be very small in some direction on the Fermi surface. In Ba(Fe1-xCox)2As2, the evolution with doping x is as follows: at low x, the gap is large everywhere on the Fermi surface, and beyond optimal doping the minimum gap becomes progressively smaller. I discuss what these features tell us about the nature of the superconducting state in pnictide superconductors. * Measurements of heat transport performed in collaboration with X.-G. Luo, H. Shakeripour, M.A. Tanatar, N. Doiron-Leyraud and L. Taillefer. [1] X.-G. Luo et al., Phys. Rev. B 80, 140503 (2009). [2] M.A. Tanatar et al., arXiv:0907.1276.

  9. Nuclear structure research. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1995-01-01

    The most significant development this year has been the realization of a method for estimating EO transition strength in nuclei and the prediction that the de-excitation (draining) of superdeformed bands must take place, at least in some cases, by strong EO transitions. A considerable effort has been devoted to planning the nuclear structure physics that will be pursued using the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge. A significant effort has been devoted to HRIBF target development. This is a critical component of the HRIBF project. Exhaustive literature searches have been made for a variety of target materials with emphasis on thermodynamic properties. Vapor pressure measurements have been carried out. Experimental data sets for radioactive decays in the very neutron-deficient Pr-Eu and Ir-Tl regions have been under analysis. These decay schemes constitute parts of student Ph.D. theses. These studies are aimed at elucidating the onset of deformation in the Pr-Sm region and the characteristics of shape coexistence in the Ir-Bi region. Further experiments on shape coexistence in the neutron-deficient Ir-Bi region are planned using α decay studies at the FMA at ATLAS. The first experiment is scheduled for later this year

  10. Harnessing the bistable composite shells to design a tunable phononic band gap structure

    Science.gov (United States)

    Li, Yi; Xu, Yanlong

    2018-02-01

    By proposing a system composed of an array of bistable composite shells immersed in air, we develop a new class of periodic structure to control the propagation of sound. Through numerical investigation, we find that the acoustic band gap of this system can be switched on and off by triggering the snap through deformation of the bistable composite shells. The shape of cross section and filling fraction of unit cell can be altered by different number of bistable composite shells, and they have strong impact on the position and width of the band gap. The proposed concept paves the way of using the bistable structures to design a new class of metamaterials that can be enable to manipulate sound.

  11. On the gap structure of UPt3: phases A and B

    International Nuclear Information System (INIS)

    Taillefer, L.; Ellman, B.; Lussier, B.; Poirier, M.

    1997-01-01

    We have used thermal conduction and transverse sound attenuation to probe the anisotropy of the gap structure in two superconducting phases of UPt 3 . For the low-temperature phase B, transverse sound has in the past provided strong evidence for a line node in the basal plane. Now, from the anisotropy of the thermal conductivity we further establish the presence of a node along the c-axis and provide information on its k-dependence. For the largely unexplored high-temperature phase A, our study of the attenuation for two directions of the polarization yields directional information on the quasiparticle spectrum, and the first clear indication of a different gap structure in the two phases. (orig.)

  12. Structural Coloration of Colloidal Fiber by Photonic Band Gap and Resonant Mie Scattering.

    Science.gov (United States)

    Yuan, Wei; Zhou, Ning; Shi, Lei; Zhang, Ke-Qin

    2015-07-01

    Because structural color is fadeless and dye-free, structurally colored materials have attracted great attention in a wide variety of research fields. In this work, we report the use of a novel structural coloration strategy applied to the fabrication of colorful colloidal fibers. The nanostructured fibers with tunable structural colors were massively produced by colloidal electrospinning. Experimental results and theoretical modeling reveal that the homogeneous and noniridescent structural colors of the electrospun fibers are caused by two phenomena: reflection due to the band gap of photonic structure and Mie scattering of the colloidal spheres. Our unprecedented findings show promise in paving way for the development of revolutionary dye-free technology for the coloration of various fibers.

  13. Safety classification of nuclear power plant systems, structures and components

    International Nuclear Information System (INIS)

    1992-01-01

    The Safety Classification principles used for the systems, structures and components of a nuclear power plant are detailed in the guide. For classification, the nuclear power plant is divided into structural and operational units called systems. Every structure and component under control is included into some system. The Safety Classes are 1, 2 and 3 and the Class EYT (non-nuclear). Instructions how to assign each system, structure and component to an appropriate safety class are given in the guide. The guide applies to new nuclear power plants and to the safety classification of systems, structures and components designed for the refitting of old nuclear power plants. The classification principles and procedures applying to the classification document are also given

  14. First Principles Study of Band Structure and Band Gap Engineering in Graphene for Device Applications

    Science.gov (United States)

    2015-03-20

    vacancy and added impurities in them are investigated using 96 atom slab of graphene . The relaxed structures and charge distribution plots of graphene 24... graphene gets reconstructed. In order to further improve the band gap opening in the graphene we introduced impurity atoms in the vacancies and...distorted Dirac cones at the Fermi point can be a check mark for presence of equal concentration of p-type and n-type impurities in graphene . The

  15. single crystal growth, x-ray structure analysis, optical band gap

    African Journals Online (AJOL)

    2015-09-01

    Sep 1, 2015 ... Hg...Hgand Cl...Cl interactions are stabilizing the structures in 3D pattern. UV-vis absorption spectra illustrate the change in opticalband gap from 3.01eVto 3.42eV on replacing the metal halide group.Raman and Hyper-Raman tensors calculations were performed based on single crystal X-ray data and the ...

  16. High power experimental studies of hybrid photonic band gap accelerator structures

    Directory of Open Access Journals (Sweden)

    JieXi Zhang

    2016-08-01

    Full Text Available This paper reports the first high power tests of hybrid photonic band gap (PBG accelerator structures. Three hybrid PBG (HPBG structures were designed, built and tested at 17.14 GHz. Each structure had a triangular lattice array with 60 inner sapphire rods and 24 outer copper rods sandwiched between copper disks. The dielectric PBG band gap map allows the unique feature of overmoded operation in a TM_{02} mode, with suppression of both lower order modes, such as the TM_{11} mode, as well as higher order modes. The use of sapphire rods, which have negligible dielectric loss, required inclusion of the dielectric birefringence in the design. The three structures were designed to sequentially reduce the peak surface electric field. Simulations showed relatively high surface fields at the triple point as well as in any gaps between components in the clamped assembly. The third structure used sapphire rods with small pin extensions at each end and obtained the highest gradient of 19  MV/m, corresponding to a surface electric field of 78  MV/m, with a breakdown probability of 5×10^{-1} per pulse per meter for a 100-ns input power pulse. Operation at a gradient above 20  MV/m led to runaway breakdowns with extensive light emission and eventual damage. For all three structures, multipactor light emission was observed at gradients well below the breakdown threshold. This research indicated that multipactor triggered at the triple point limited the operational gradient of the hybrid structure.

  17. The Influence of Nuclear Reactions and Nuclear Structure in Astrophysics

    Science.gov (United States)

    Rehm, K. E.

    2017-11-01

    Nuclear reactions play an important role for the energy production and the nucleosynthesis in stars. New facilities, able to accelerate radioactive nuclei or high-intensity stable beams have allowed us to measure in the laboratory reactions involving short-lived nuclei or processes with very small cross sections, which are crucial for stellar nucleosynthesis. I will discuss some of the recent experiments studying fusion and transfer reactions with radioactive beams which play a critical role in various quiescent and explosive stellar environments.

  18. New frontiers in nuclear structure studies

    International Nuclear Information System (INIS)

    Zwarts, D.; Walet, N.R.; Wolters, A.A.; Glaudemans, P.W.M.; VandeGraff, R.J.

    1985-01-01

    The need to go to larger model spaces for more detailed studies of the atomic nucleus has led to the introduction of the supercomputer to nuclear physics. In this report a brief survey of the nuclear shell model is presented and the performance of some of the relevant programs on different computer systems is compared

  19. Wide-gap layered oxychalcogenide semiconductors: Materials, electronic structures and optoelectronic properties

    International Nuclear Information System (INIS)

    Ueda, Kazushige; Hiramatsu, Hidenori; Hirano, Masahiro; Kamiya, Toshio; Hosono, Hideo

    2006-01-01

    Applying the concept of materials design for transparent conductive oxides to layered oxychalcogenides, several p-type and n-type layered oxychalcogenides were proposed as wide-gap semiconductors and their basic optical and electrical properties were examined. The layered oxychalcogenides are composed of ionic oxide layers and covalent chalcogenide layers, which bring wide-gap and conductive properties to these materials, respectively. The electronic structures of the materials were examined by normal/inverse photoemission spectroscopy and energy band calculations. The results of the examinations suggested that these materials possess unique features more than simple wide-gap semiconductors. Namely, the layered oxychalcogenides are considered to be extremely thin quantum wells composed of the oxide and chalcogenide layers or 2D chalcogenide crystals/molecules embedded in an oxide matrix. Observation of step-like absorption edges, large band gap energy and large exciton binding energy demonstrated these features originating from 2D density of states and quantum size effects in these layered materials

  20. Design of concrete structures important to safety of nuclear facilities

    International Nuclear Information System (INIS)

    2001-10-01

    Civil engineering structures in nuclear installations form an important feature having implications to safety performance of these installations. The objective and minimum requirements for the design of civil engineering buildings/structures to be fulfilled to provide adequate assurance for safety of nuclear installations in India (such as pressurised heavy water reactor and related systems) are specified in the Safety standard for civil engineering structures important to safety of nuclear facilities. This standard is written by AERB to specify guidelines for implementation of the above civil engineering safety standard in the design of concrete structures important to safety

  1. Complex layered materials and periodic electromagnetic band-gap structures: Concepts, characterizations, and applications

    Science.gov (United States)

    Mosallaei, Hossein

    The main objective of this dissertation is to characterize and create insight into the electromagnetic performances of two classes of composite structures, namely, complex multi-layered media and periodic Electromagnetic Band-Gap (EBG) structures. The advanced and diversified computational techniques are applied to obtain their unique propagation characteristics and integrate the results into some novel applications. In the first part of this dissertation, the vector wave solution of Maxwell's equations is integrated with the Genetic Algorithm (GA) optimization method to provide a powerful technique for characterizing multi-layered materials, and obtaining their optimal designs. The developed method is successfully applied to determine the optimal composite coatings for Radar Cross Section (RCS) reduction of canonical structures. Both monostatic and bistatic scatterings are explored. A GA with hybrid planar/curved surface implementation is also introduced to efficiently obtain the optimal absorbing materials for curved structures. Furthermore, design optimization of the non-uniform Luneburg and 2-shell spherical lens antennas utilizing modal solution/GA-adaptive-cost function is presented. The lens antennas are effectively optimized for both high gain and suppressed grating lobes. The second part demonstrates the development of an advanced computational engine, which accurately computes the broadband characteristics of challenging periodic electromagnetic band-gap structures. This method utilizes the Finite Difference Time Domain (FDTD) technique with Periodic Boundary Condition/Perfectly Matched Layer (PBC/PML), which is efficiently integrated with the Prony scheme. The computational technique is successfully applied to characterize and present the unique propagation performances of different classes of periodic structures such as Frequency Selective Surfaces (FSS), Photonic Band-Gap (PBG) materials, and Left-Handed (LH) composite media. The results are

  2. Observation of Wakefield Suppression in a Photonic-Band-Gap Accelerator Structure

    Science.gov (United States)

    Simakov, Evgenya I.; Arsenyev, Sergey A.; Buechler, Cynthia E.; Edwards, Randall L.; Romero, William P.; Conde, Manoel; Ha, Gwanghui; Power, John G.; Wisniewski, Eric E.; Jing, Chunguang

    2016-02-01

    We report experimental observation of higher order mode (HOM) wakefield suppression in a room-temperature traveling-wave photonic-band-gap (PBG) accelerating structure at 11.700 GHz. It has been long recognized that PBG structures have the potential for reducing long-range wakefields in accelerators. The first ever demonstration of acceleration in a room-temperature PBG structure was conducted in 2005. Since then, the importance of PBG accelerator research has been recognized by many institutions. However, the full experimental characterization of the wakefield spectrum and demonstration of wakefield suppression when the accelerating structure is excited by an electron beam has not been performed to date. We conducted an experiment at the Argonne Wakefield Accelerator test facility and observed wakefields excited by a single high charge electron bunch when it passes through a PBG accelerator structure. Excellent HOM suppression properties of the PBG accelerator were demonstrated in the beam test.

  3. Integrative structure and functional anatomy of a nuclear pore complex

    Science.gov (United States)

    Kim, Seung Joong; Fernandez-Martinez, Javier; Nudelman, Ilona; Shi, Yi; Zhang, Wenzhu; Raveh, Barak; Herricks, Thurston; Slaughter, Brian D.; Hogan, Joanna A.; Upla, Paula; Chemmama, Ilan E.; Pellarin, Riccardo; Echeverria, Ignacia; Shivaraju, Manjunatha; Chaudhury, Azraa S.; Wang, Junjie; Williams, Rosemary; Unruh, Jay R.; Greenberg, Charles H.; Jacobs, Erica Y.; Yu, Zhiheng; de La Cruz, M. Jason; Mironska, Roxana; Stokes, David L.; Aitchison, John D.; Jarrold, Martin F.; Gerton, Jennifer L.; Ludtke, Steven J.; Akey, Christopher W.; Chait, Brian T.; Sali, Andrej; Rout, Michael P.

    2018-03-01

    Nuclear pore complexes play central roles as gatekeepers of RNA and protein transport between the cytoplasm and nucleoplasm. However, their large size and dynamic nature have impeded a full structural and functional elucidation. Here we determined the structure of the entire 552-protein nuclear pore complex of the yeast Saccharomyces cerevisiae at sub-nanometre precision by satisfying a wide range of data relating to the molecular arrangement of its constituents. The nuclear pore complex incorporates sturdy diagonal columns and connector cables attached to these columns, imbuing the structure with strength and flexibility. These cables also tie together all other elements of the nuclear pore complex, including membrane-interacting regions, outer rings and RNA-processing platforms. Inwardly directed anchors create a high density of transport factor-docking Phe-Gly repeats in the central channel, organized into distinct functional units. This integrative structure enables us to rationalize the architecture, transport mechanism and evolutionary origins of the nuclear pore complex.

  4. Proton capture reactions and nuclear structure

    International Nuclear Information System (INIS)

    Kikstra, S.W.

    1989-01-01

    Experimental studies are described of the structure of 40 Ca and 42 Sc with measurements at proton-capture of (p, gamma) reactions. Where possible, an attempt has been made to interpret the results of the measurements in termsof existing models. The 40 Ca and 42 Sc nuclides were excited by bombarding 39 K and 41 Ca targets, respectively with low energy protons (E p = 0.3-3.0 MeV), that were produced by the Utrecht 3MV van de Graaff accelerator. From the measured energy and intensity of the gamma-rays created in the subsequent decay of the cuclei, information was obtained on the existence and properties of their excited states. In addition properties of two T = 3/2 levels at high excitation energy of the 9 Be nucleus were investigated. These levels were excited by the resonant absorption of gamma-rays from the 11 B(p, gamma) 12 C reaction. The results of the measurements are interpreted by a comparison to the analoque β-decay of 9 Li and to shell model calculations. The total decay energy of the superallowed O + → O + transition between the ground states of 42 Sc and 42 Ca was determined by measurements in Utrecht of the proton separation energy S p of 42 Sc and in Oak Ridge of S n of 42 Sc and 42 Ca. The results were used for verification of the conserved vector current hypothesis, which implies that the ft values of all superallowed O + → O + β-decays are the same. An attempt was made to describe properties of odd-parity states of A = 37-41 nuclei with a variant of the Warburton, Becker, Millener and Brown (WBMB) interaction.Finally a new method for the assignment of nuclear spins by a simple statistical analysis of spectroscopic information is proposed. (author). 169 refs.; 22 figs.; 24 schemes; 29 tabs

  5. Electronic structures and band gaps of chains and sheets based on phenylacetylene units

    International Nuclear Information System (INIS)

    Kondo, Masakazu; Nozaki, Daijiro; Tachibana, Masamitsu; Yumura, Takashi; Yoshizawa, Kazunari

    2005-01-01

    We investigate the electronic structures of polymers composed of π-conjugated phenylacetylene (PA) units, m-PA-based and p-PA-based wires, at the extended Hueckel level of theory. It is demonstrated that these conjugated systems should have a variety of electric conductance. All of the one-dimensional (1D) chains and the two-dimensional (2D) sheet based on the m-PA unit are insulators with large band gaps of 2.56 eV because there is no effective orbital interaction with neighboring chains. On the other hand, p-PA-based 1D chains have relatively small band gaps that decrease with an increase in chain width (1.17-1.74 eV) and are semiconductive. The p-PA-based sheet called 'graphyne', a 2D-limit of the p-PA-based 1D chains, shows a small band gap of 0.89 eV. The variety of band electronic structures is discussed in terms of frontier crystal orbitals

  6. Vertical Line Nodes in the Superconducting Gap Structure of Sr_{2}RuO_{4}

    Directory of Open Access Journals (Sweden)

    E. Hassinger

    2017-03-01

    Full Text Available There is strong experimental evidence that the superconductor Sr_{2}RuO_{4} has a chiral p-wave order parameter. This symmetry does not require that the associated gap has nodes, yet specific heat, ultrasound, and thermal conductivity measurements indicate the presence of nodes in the superconducting gap structure of Sr_{2}RuO_{4}. Theoretical scenarios have been proposed to account for the existence of deep minima or accidental nodes (minima tuned to zero or below by material parameters within a p-wave state. Other scenarios propose chiral d-wave and f-wave states, with horizontal and vertical line nodes, respectively. To elucidate the nodal structure of the gap, it is essential to know whether the lines of nodes (or minima are vertical (parallel to the tetragonal c axis or horizontal (perpendicular to the c axis. Here, we report thermal conductivity measurements on single crystals of Sr_{2}RuO_{4} down to 50 mK for currents parallel and perpendicular to the c axis. We find that there is substantial quasiparticle transport in the T=0 limit for both current directions. A magnetic field H immediately excites quasiparticles with velocities both in the basal plane and in the c direction. Our data down to T_{c}/30 and down to H_{c2}/100 show no evidence that the nodes are in fact deep minima. Relative to the normal state, the thermal conductivity of the superconducting state is found to be very similar for the two current directions, from H=0 to H=H_{c2}. These findings show that the gap structure of Sr_{2}RuO_{4} consists of vertical line nodes. This rules out a chiral d-wave state. Given that the c-axis dispersion (warping of the Fermi surface in Sr_{2}RuO_{4} varies strongly from sheet to sheet, the small a-c anisotropy suggests that the line nodes are present on all three sheets of the Fermi surface. If imposed by symmetry, vertical line nodes would be inconsistent with a p-wave order parameter for Sr_{2}RuO_{4}. To reconcile the gap structure

  7. Vertical Line Nodes in the Superconducting Gap Structure of Sr2 RuO4

    Science.gov (United States)

    Hassinger, E.; Bourgeois-Hope, P.; Taniguchi, H.; René de Cotret, S.; Grissonnanche, G.; Anwar, M. S.; Maeno, Y.; Doiron-Leyraud, N.; Taillefer, Louis

    2017-01-01

    There is strong experimental evidence that the superconductor Sr2 RuO4 has a chiral p -wave order parameter. This symmetry does not require that the associated gap has nodes, yet specific heat, ultrasound, and thermal conductivity measurements indicate the presence of nodes in the superconducting gap structure of Sr2 RuO4 . Theoretical scenarios have been proposed to account for the existence of deep minima or accidental nodes (minima tuned to zero or below by material parameters) within a p -wave state. Other scenarios propose chiral d -wave and f -wave states, with horizontal and vertical line nodes, respectively. To elucidate the nodal structure of the gap, it is essential to know whether the lines of nodes (or minima) are vertical (parallel to the tetragonal c axis) or horizontal (perpendicular to the c axis). Here, we report thermal conductivity measurements on single crystals of Sr2 RuO4 down to 50 mK for currents parallel and perpendicular to the c axis. We find that there is substantial quasiparticle transport in the T =0 limit for both current directions. A magnetic field H immediately excites quasiparticles with velocities both in the basal plane and in the c direction. Our data down to Tc/30 and down to Hc 2/100 show no evidence that the nodes are in fact deep minima. Relative to the normal state, the thermal conductivity of the superconducting state is found to be very similar for the two current directions, from H =0 to H =Hc 2. These findings show that the gap structure of Sr2 RuO4 consists of vertical line nodes. This rules out a chiral d -wave state. Given that the c -axis dispersion (warping) of the Fermi surface in Sr2 RuO4 varies strongly from sheet to sheet, the small a -c anisotropy suggests that the line nodes are present on all three sheets of the Fermi surface. If imposed by symmetry, vertical line nodes would be inconsistent with a p -wave order parameter for Sr2 RuO4 . To reconcile the gap structure revealed by our data with a p -wave

  8. Changes in attitude structure toward nuclear power in the nuclear power plant locations of Tohoku district

    International Nuclear Information System (INIS)

    Tsujikawa, Norifumi; Tsuchida, Shoji; Shiotani, Takamasa; Nakagawa, Yuri

    2012-01-01

    This survey was examined the changes in structure of attitude toward nuclear power and the influence of environmental value on the attitude structure before and after the accident at the Fukushima No. 1 nuclear power plant. With residents of Aomori, Miyagi, and Fukushima prefectures as participants, we conducted online surveys in November 2009 and October 2011. Comparing the results before and after the accident, we found that trust in the management of nuclear power plants had a stronger influence on the perceived risk and benefit regarding nuclear power after the accident than before the accident. The value of concern about environmental destruction resulted in reduced trust in the management. (author)

  9. Relativistic density functional for nuclear structure

    CERN Document Server

    2016-01-01

    This book aims to provide a detailed introduction to the state-of-the-art covariant density functional theory, which follows the Lorentz invariance from the very beginning and is able to describe nuclear many-body quantum systems microscopically and self-consistently. Covariant density functional theory was introduced in nuclear physics in the 1970s and has since been developed and used to describe the diversity of nuclear properties and phenomena with great success. In order to provide an advanced and updated textbook of covariant density functional theory for graduate students and nuclear physics researchers, this book summarizes the enormous amount of material that has accumulated in the field of covariant density functional theory over the last few decades as well as the latest developments in this area. Moreover, the book contains enough details for readers to follow the formalism and theoretical results, and provides exhaustive references to explore the research literature.

  10. Nuclear structure studies of F-24

    Czech Academy of Sciences Publication Activity Database

    Caceres, L.; Lepailleur, A.; Sorlin, O.; Stanoiu, M.; Grévy, S.; Mrázek, Jaromír; Negoita, F.; de Oliveira Santos, F.; Penionzhkevich, Y. E.; Rotaru, F.

    2015-01-01

    Roč. 92, č. 1 (2015), 014327 ISSN 0556-2813 Institutional support: RVO:61389005 Keywords : spectrometer * GANIL * forces Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.146, year: 2015

  11. Periodic dielectric structure for production of photonic band gap and method for fabricating the same

    Science.gov (United States)

    Ozbay, Ekmel; Tuttle, Gary; Michel, Erick; Ho, Kai-Ming; Biswas, Rana; Chan, Che-Ting; Soukoulis, Costas

    1995-01-01

    A method for fabricating a periodic dielectric structure which exhibits a photonic band gap. Alignment holes are formed in a wafer of dielectric material having a given crystal orientation. A planar layer of elongate rods is then formed in a section of the wafer. The formation of the rods includes the step of selectively removing the dielectric material of the wafer between the rods. The formation of alignment holes and layers of elongate rods and wafers is then repeated to form a plurality of patterned wafers. A stack of patterned wafers is then formed by rotating each successive wafer with respect to the next-previous wafer, and then placing the successive wafer on the stack. This stacking results in a stack of patterned wafers having a four-layer periodicity exhibiting a photonic band gap.

  12. Stress analysis of disconnected structures in contact through finite element gaps

    International Nuclear Information System (INIS)

    Stadter, J.T.; Weiss, R.O.

    1976-07-01

    A numerical procedure is presented for analyzing thermal stress problems of disconnected structures in contact across separations or gaps. The new procedure is called SAASGAPS, an adaptation of the basic SAAS III computer program. The SAAS program uses the finite element method and allows analyses of plane and axisymmetric bodies with temperature dependent material properties, subject to thermal and mechanical loads. A secant modulus approach with a bilinear stress-strain curve is used for elastic-plastic problems. The SAASGAPS version contains all of the features of the original SAAS program. A special gap element is used together with a stress invariance principle to model the contact process. The iterative procedure implemented in SAASGAPS is described. Results are discussed for five problems involving frictionless contact. Two of these problems are associated with the thermal stress analysis of the heat shield for the Multi-Hundred Watt Radioisotope Thermoelectric Generator. Input instructions for the program are described in an appendix

  13. Band gap widening and quantum tunnelling effects of Ag/MgO/p-Si MOS structure

    Science.gov (United States)

    Kamarulzaman, Norlida; Badar, Nurhanna; Fadilah Chayed, Nor; Firdaus Kasim, Muhd

    2016-10-01

    MgO films of various thicknesses were fabricated via the pulsed laser deposition method. The MgO thin films obtained have the advantage of high quality mirror finish, good densification and of uniform thickness. The MgO thin films have thicknesses of between 43 to 103 nm. They are polycrystalline in nature with oriented growth mainly in the direction of the [200] and [220] crystal planes. It is observed that the band gap of the thin films increases as the thickness decreases due to quantum effects, however, turn-on voltage has the opposite effect. The decrease of the turn-on as well as the tunnelling voltage of the thinner films, despite their larger band gap, is a direct experimental evidence of quantum tunnelling effects in the thin films. This proves that quantum tunnelling is more prominent in low dimensional structures.

  14. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1977-10-01

    This is the third issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation is published and distributed by the IAEA Nuclear Data Section approximately every six months. This compilation of compilations and evaluations is designed to keep the nuclear scientific community informed of the availability of compiled or evaluated NSD data, and contains references to laboratory reports, journal articles and books containing selected compilations and evaluations

  15. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.; Graves, H.L. III; Norris, W.E.

    1994-01-01

    Research is being conducted by ORNL under US Nuclear Regulatory Commission (USNRC) sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of nondestructive evaluation techniques. assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants

  16. Procedures manual for the Evaluated Nuclear Structure Data File

    International Nuclear Information System (INIS)

    Bhat, M.R.

    1987-10-01

    This manual is a collection of various notes, memoranda and instructions on procedures for the evaluation of data in the Evaluated Nuclear Structure Data File (ENSDF). They were distributed at different times over the past few years to the evaluators of nuclear structure data and some of them were not readily avaialble. Hence, they have been collected in this manual for ease of reference by the evaluators of the international Nuclear Structure and Decay Data (NSDD) network contribute mass-chains to the ENSDF. Some new articles were written specifically for this manual and others are reivsions of earlier versions

  17. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    Science.gov (United States)

    Munroe, Brian J.; Zhang, JieXi; Xu, Haoran; Shapiro, Michael A.; Temkin, Richard J.

    2016-03-01

    We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG) accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV /m at a breakdown probability of 1.19 ×10-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90 MV /m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV /m at a breakdown probability of 1.09 ×10-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  18. Transport in bilayer and trilayer graphene: band gap engineering and band structure tuning

    Science.gov (United States)

    Zhu, Jun

    2014-03-01

    Controlling the stacking order of atomically thin 2D materials offers a powerful tool to control their properties. Linearly dispersed bands become hyperbolic in Bernal (AB) stacked bilayer graphene (BLG). Both Bernal (ABA) and rhombohedral (ABC) stacking occur in trilayer graphene (TLG), producing distinct band structures and electronic properties. A symmetry-breaking electric field perpendicular to the sample plane can further modify the band structures of BLG and TLG. In this talk, I will describe our experimental effort in these directions using dual-gated devices. Using thin HfO2 film deposited by ALD as gate dielectric, we are able to apply large displacement fields D > 6 V/nm and observe the opening and saturation of the field-induced band gap Eg in bilayer and ABC-stacked trilayer graphene, where the conduction in the mid gap changes by more than six decades. Its field and temperature dependence highlights the crucial role played by Coulomb disorder in facilitating hopping conduction and suppressing the effect of Eg in the tens of meV regime. In contrast, mid-gap conduction decreases with increasing D much more rapidly in clean h-BN dual-gated devices. Our studies also show the evolution of the band structure in ABA-stacked TLG, in particular the splitting of the Dirac-like bands in large D field and the signatures of two-band transport at high carrier densities. Comparison to theory reveals the need for more sophisticated treatment of electronic screening beyond self-consistent Hartree calculations to accurately predict the band structures of trilayer graphene and graphenic materials in general.

  19. Band Gap Opening Induced by the Structural Periodicity in Epitaxial Graphene Buffer Layer.

    Science.gov (United States)

    N Nair, Maya; Palacio, Irene; Celis, Arlensiú; Zobelli, Alberto; Gloter, Alexandre; Kubsky, Stefan; Turmaud, Jean-Philippe; Conrad, Matthew; Berger, Claire; de Heer, Walter; Conrad, Edward H; Taleb-Ibrahimi, Amina; Tejeda, Antonio

    2017-04-12

    The epitaxial graphene buffer layer on the Si face of hexagonal SiC shows a promising band gap, of which the precise origin remains to be understood. In this work, we correlate the electronic to the atomic structure of the buffer layer by combining angle resolved photoemission spectroscopy (ARPES), scanning tunneling microscopy (STM), and high-resolution scanning transmission electron microscopy (HR-STEM). We show that the band structure in the buffer has an electronic periodicity related to the structural periodicity observed in STM images and published X-ray diffraction. Our HR-STEM measurements show the bonding of the buffer layer to the SiC at specific locations separated by 1.5 nm. This is consistent with the quasi 6 × 6 periodic corrugation observed in the STM images. The distance between buffer C and SiC is 1.9 Å in the bonded regions and up to 2.8 Å in the decoupled regions, corresponding to a 0.9 Å corrugation of the buffer layer. The decoupled regions are sp 2 hybridized. Density functional tight binding (DFTB) calculations demonstrate the presence of a gap at the Dirac point everywhere in the buffer layer, even in the decoupled regions where the buffer layer has an atomic structure close to that of graphene. The surface periodicity also promotes band in the superperiodic Brillouin zone edges as seen by photoemission and confirmed by our calculations.

  20. Nuclear structure far from stability: the neutron-rich 69-79Cu isotopes

    International Nuclear Information System (INIS)

    Franchoo, Serge

    2015-01-01

    Far from stability, the nuclear structure that is predicted by the shell model is evolving. Old magic numbers disappear, while new ones appear. Our understanding of the underlying nuclear force that drives these changes is still incomplete. After a short overview across the nuclear chart, we discuss the strength functions of the shell-model orbitals in the neutron-rich copper isotopes towards the 78 Ni doubly-magic nucleus. These were measured in a 72 Zn(d, 3 He) 71 Cu proton pick-up reaction in inverse kinematics with a radioactive beam at the Ganil laboratory in France. We also present the latest results from a 80 Zn(p,2p) 79 Cu knockout experiment at Riken in Japan, leading to selective population of hole states in 79 Cu. Our findings show that the Z=28 shell gap in the neutron-rich copper isotopes is surprisingly steady against the addition of neutrons beyond N=40. (author)

  1. A workshop report on nuclear reaction and cluster structure

    International Nuclear Information System (INIS)

    1985-01-01

    A work shop was held in June 1984 at RCNP (Research Center for Nuclear Physics), Osaka University, to discuss theory of nuclear reactions based on studies from microscopic or cluster structure viewpoints. About forty researchers participated in this work shop and 27 paperes were presented. All these papers with English abstracts are gathered in this collective report. (Aoki, K.)

  2. Nuclear structure at high spin using multidetector gamma array and ...

    Indian Academy of Sciences (India)

    2014-04-05

    Apr 5, 2014 ... Nuclear structure at high spin. Figure 1. Schematic of the orientation of HPGe detector in GDA [4]. These signals were fed to custom-made data acquisition system Freedom [10] which was later used for data reduction. We recorded γ-ray fold of nuclear reaction using multiplicity filter made of BGO scin-.

  3. Particle production from nuclear targets and the structure of hadrons

    International Nuclear Information System (INIS)

    Bialas, A.

    Production processes from nuclear targets allow studying interactions of elementary hadronic constituents in nuclear matter. The information thus obtained on the structure of hadrons and on the properties of hadronic constituents is presented. Both soft (low momentum transfer) and hard (high momentum transfer) processes are discussed. (author)

  4. Nuclear receptors and endocrine disruptors in fetal and neonatal testes: a gapped landscape.

    Directory of Open Access Journals (Sweden)

    Virginie eRouiller-Fabre

    2015-05-01

    Full Text Available During the last decades, many studies reported that male reproductive disorders are increasing among humans. It is currently acknowledged that these abnormalities can result from fetal exposure to environmental chemicals that are progressively becoming more concentrated and widespread in our environment. Among the chemicals present in the environment (air, water, food and many consumer products, several can act as endocrine disrupting compounds (EDCs, thus interfering with the endocrine system. Phthalates, bisphenol A (BPA and diethylstilbestrol (DES have been largely incriminated, particularly during the fetal and neonatal period, due to their estrogenic and/or anti-androgenic properties. Indeed, many epidemiological and experimental studies have highlighted their deleterious impact on fetal and neonatal testis development. As EDCs can affect many different genomic and non-genomic pathways, the mechanisms underlying the adverse effects of EDC exposure are difficult to elucidate. Using literature data and results from our laboratory, in the present review we discuss the role of classical nuclear receptors (genomic pathway in the fetal and neonatal testis response to EDC exposure, particularly to phthalates, BPA and DES. Among the nuclear receptors we focused on some of the most likely candidates, such as peroxisome-proliferator activated receptor (PPAR, androgen receptor (AR, estrogen receptors (ERα and β, liver X receptors (LXR and small heterodimer partner (SHP. First, we describe the expression and potential functions (based on data from studies using receptor agonists and mouse knockout models of these nuclear receptors in the developing testis. Then, for each EDC studied, we summarize the main evidences indicating that the reprotoxic effect of each EDC under study is mediated through a specific nuclear receptor(s. We also point-out the involvement of other receptors and nuclear receptor-independent pathways.

  5. A New Light Weight Structural Material for Nuclear Structures

    Energy Technology Data Exchange (ETDEWEB)

    Rabiei, Afsaneh [North Carolina State Univ., Raleigh, NC (United States)

    2016-01-14

    Radiation shielding materials are commonly used in nuclear facilities to attenuate the background ionization radiations to a minimum level for creating a safer workplace, meeting regulatory requirements and maintaining high quality performance. The conventional radiation shielding materials have a number of drawbacks: heavy concrete contains a high amount of elements that are not desirable for an effective shielding such as oxygen, silicon, and calcium; a well known limitation of lead is its low machinability and toxicity, which is causing a major environmental concern. Therefore, an effective and environmentally friendly shielding material with increased attenuation and low mass density is desirable. Close-cell composite metal foams (CMFs) and open-cell Al foam with fillers are light-weight candidate materials that we have studied in this project. Close-cell CMFs possess several suitable properties that are unattainable by conventional radiation shielding materials such as low density and high strength for structural applications, high surface area to volume ratio for excellent thermal isolation with an extraordinary energy absorption capability. Open-cell foam is made up of a network of interconnected solid struts, which allows gas or fluid media to pass through it. This unique structure provided a further motive to investigate its application as radiation shields by infiltrating original empty pores with high hydrogen or boron compounds, which are well known for their excellent neutron shielding capability. The resulting open-cell foam with fillers will not only exhibit light weight and high specific surface area, but also possess excellent radiation shielding capability and good processability. In this study, all the foams were investigated for their radiation shielding efficiency in terms of X-ray, gamma ray and neutron. X-ray transmission measurements were carried out on a high-resolution microcomputed tomography (microCT) system. Gamma-emitting sources: 3.0m

  6. Indirect exchange interaction between magnetic impurities in a gapped graphene structure

    Directory of Open Access Journals (Sweden)

    H. Rezania

    2017-03-01

    Full Text Available We study exchange interaction between two magnetic impurities in doped gapped graphene (the Ruderman-Kittel-Kasuya-Yosida [RKKY] interaction by directly computing Green’s function beyond Dirac approximation. Tight binding model Hamiltonian in the presence of magnetic long range ordering has been applied to describe electron dynamics. RKKY interaction as a function of distance between localized moments has been analyzed. It has been shown that a magnetic ordering along the z-axis mediates two different interactions for spin directions which corresponds to a XXZ model interaction between two magnetic moments. The exchange interaction along arbitrary direction between two magnetic moments, has been obtained using the static spin susceptibilities of gapped graphene structure. The effects of spin polarization on the the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show the chemical potential impacts the spatial behavior of RKKY interaction. Moreover gap parameter effects on RKKY interaction have been investigated in details.

  7. Isotopically enriched structural materials in nuclear devices

    International Nuclear Information System (INIS)

    Morgan, L.W.G.; Shimwell, J.; Gilbert, M.R.

    2015-01-01

    Highlights: • C-B analysis of isotopic enrichment of structural materials is presented. • Some, previously, prohibited elements could be used as alloying elements in LAM's. • Adding enriched molybdenum and nickel, to EUROFER, could increase availability. • Isotope enrichment for EUROFER could be cost-effective. • Isotopically enriching copper, in CuCrZr, can reduce helium production by 50%. - Abstract: A large number of materials exist which have been labeled as low activation structural materials (LAM). Most often, these materials have been designed in order to substitute-out or completely remove elements that become activated and contribute significantly to shut-down activity after being irradiated by neutrons in a reactor environment. To date, one of the fundamental principles from which LAMs have been developed is that natural elemental compositions are the building blocks of LAMs. Thus, elements such as Co, Al, Ni, Mo, Nb, N and Cu that produce long-lived decay products are significantly reduced or removed from the LAM composition. These elements have an important part to play in the composition of steels and the removal/substitution can have a negative impact on materials properties such as yield stress and fracture toughness. This paper looks in more detail at whether using isotopic selection of the more mechanically desirable, but prohibited due to activation, elements can improve matters. In particular, this paper focuses on the activation of Eurofer. Carefully chosen isotopically enriched elements, which are normally considered to be on the prohibited element list, are added to EUROFER steel as potential alloying elements. The EUROFER activation results show that some prohibited elements can be used as alloying elements in LAM steels, providing the selected isotopes do not have a significant impact on waste disposal rating or shut-down dose. The economic implications of isotopically enriching elements and the potential implications for

  8. The R-factor gap in macromolecular crystallography: an untapped potential for insights on accurate structures.

    Science.gov (United States)

    Holton, James M; Classen, Scott; Frankel, Kenneth A; Tainer, John A

    2014-09-01

    In macromolecular crystallography, the agreement between observed and predicted structure factors (Rcryst and Rfree ) is seldom better than 20%. This is much larger than the estimate of experimental error (Rmerge ). The difference between Rcryst and Rmerge is the R-factor gap. There is no such gap in small-molecule crystallography, for which calculated structure factors are generally considered more accurate than the experimental measurements. Perhaps the true noise level of macromolecular data is higher than expected? Or is the gap caused by inaccurate phases that trap refined models in local minima? By generating simulated diffraction patterns using the program MLFSOM, and including every conceivable source of experimental error, we show that neither is the case. Processing our simulated data yielded values that were indistinguishable from those of real data for all crystallographic statistics except the final Rcryst and Rfree . These values decreased to 3.8% and 5.5% for simulated data, suggesting that the reason for high R-factors in macromolecular crystallography is neither experimental error nor phase bias, but rather an underlying inadequacy in the models used to explain our observations. The present inability to accurately represent the entire macromolecule with both its flexibility and its protein-solvent interface may be improved by synergies between small-angle X-ray scattering, computational chemistry and crystallography. The exciting implication of our finding is that macromolecular data contain substantial hidden and untapped potential to resolve ambiguities in the true nature of the nanoscale, a task that the second century of crystallography promises to fulfill. Coordinates and structure factors for the real data have been submitted to the Protein Data Bank under accession 4tws. © 2014 The Authors. FEBS Journal published by John Wiley & Sons Ltd on behalf of FEBS.

  9. Report of seminar on relativistic approach to nuclear reaction and nuclear structure

    International Nuclear Information System (INIS)

    1986-05-01

    A seminar on 'Relativistic Approach to Nuclear Reaction and Nuclear Structure' was held in 1985 at Osaka University. This booklet includes twenty-four reports given at the seminar, which deal with: Conventional Nonrelativistic Description of Nuclear Matter and Nuclear Spin-Orbit Interactions; Relativistic Approach to Nuclear Structure; Atomic and Molecular Structure Calculations; Electromagnetic Interaction in Nucleus and Relativistic Effect; Nuclear Magnetic Moment in the Relativistic Mean Field Theory, Effective Mass and Particle-Vibration Coupling in the Relativistic σ-ω Model; Gauge Invariance in Relativistic Many-Body Theory; Relativistic Description of Nucleon-Nucleon Interaction in Review; σ-Particle in NN Interaction; Nuclear Optical Potentials Based on the Brueckner-Hartree-Fock Approach; Elastic Backscattering and Optical Potential; Description of Intermediate-Energy Nuclear Reactions; Dirac Phenomenology at E(p) = 65 MeV; Relativistic Impulse Approximation; Reaction Studies with Intermediate Energy Deuterons at SATURNE; Folding Model for Intermediate-Energy Deutron Scattering; Folding Model for Polarized Deutron Scattering at 700 MeV; Dirac Approach Problems and a Different Viewpoint; Relativistic Approach and EMC Effect; Quasielastic Electron Scattering; Response Function of Quasielastic Electron Scattering; Relativistic Hartree Response Function for Quasielastic Electron Scattering on 12 C and 40 Ca; Backflow-, Retardation- and Relativistic Effects on the Longitudinal Response Function of Nuclear Matter; Pion-Photoproduction in the σ-ω Model. (Nogami, K.)

  10. Impact of the structural changes on the nuclear safety

    International Nuclear Information System (INIS)

    Ziakova, M.

    2005-01-01

    In this presentation author deals with impact of the structural changes (privatization of the Slovenske Elektrarne, a.s.) and new Atomic law (541/2004 Coll. Laws) on the nuclear safety in the Slovak Republic.

  11. Nuclear reactor fuel assemblies and end fitting grid structures therefor

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1978-01-01

    An improved end fitting grid structure is described for nuclear fuel assemblies which overcomes the need for load-bearing control rod guide tubes and the expensive special fittings that these tubes required. (UK)

  12. Stress Management and Nuclear Anxiety: A Structured Group Experience.

    Science.gov (United States)

    Bisio, Thomas A.; Crisan, Pamela

    1984-01-01

    Describes a structured workshop in which group members explore their fears of nuclear holocaust and the effects this fear has had on their lives. By using logotherapy ideals, the participants create a renewed sense of purpose and hope. (Author)

  13. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    1989-08-01

    During the past year, research in theoretical nuclear physics at the University of Maryland attained a number of exciting and important results. These are described in some detail throughout the report, but some of the highlights are as follows: large N c QCD has been shown to place strong constraints on vacuum effects of hadronic field theories; color dielectric models of hadrons have been understood in terms of lattice QCD; we have completed a relativistic analysis of proton scattering to test virtual pair contributions; we have also re-derived the Mandelzweig-Wallace two-body Dirac equation in covariant form, and applied it to the atomic two-body bound states: hydrogen, muonium and positronium; we have carried out the first calculation of the triton binding energy with a realistic quark-based nucleon-nucleon interaction and have learned that new kinds of nonlocalities in the tensor force may produce unexpected results; and we have shown that the Quadronium Conjecture can lead to spontaneous creation of the atom with low momentum as required by the observations, and are constructing a model to quantify the Quadronium phenomenology of the e + e - Puzzle

  14. Construction of special structures for nuclear power projects

    International Nuclear Information System (INIS)

    Raghavan, N.

    2003-01-01

    Construction is a very important stage in the course of realization of Nuclear Power Projects and as much care has be devoted to this stage as to the planning and engineering stages. While the setting up of nuclear power projects used to take over seven years in the past, the time period has now been considerably reduced to about five years with advancements in construction engineering, project management and design techniques, on the basis of new initiatives from the owner agency, Nuclear Power Corporation of India. In this article, the constructional aspects of the specialized structures for nuclear power generation are looked into. (author)

  15. Gap junction structure: unraveled, but not fully revealed [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Eric C. Beyer

    2017-04-01

    Full Text Available Gap junction channels facilitate the intercellular exchange of ions and small molecules, a process that is critical for the function of many different kinds of cells and tissues. Recent crystal structures of channels formed by one connexin isoform (connexin26 have been determined, and they have been subjected to molecular modeling. These studies have provided high-resolution models to gain insights into the mechanisms of channel conductance, molecular permeability, and gating. The models share similarities, but there are some differences in the conclusions reached by these studies. Many unanswered questions remain to allow an atomic-level understanding of intercellular communication mediated by connexin26. Because some domains of the connexin polypeptides are highly conserved (like the transmembrane regions, it is likely that some features of the connexin26 structure will apply to other members of the family of gap junction proteins. However, determination of high-resolution structures and modeling of other connexin channels will be required to account for the diverse biophysical properties and regulation conferred by the differences in their sequences.

  16. Silicon-based photocells of enhanced spectral sensitivity with nano-sized graded band gap structures

    International Nuclear Information System (INIS)

    Bakhadyrkhanov, M.K.; Isamov, S.B.; Iliev, K.M. et al.

    2014-01-01

    Photoelectric properties of monocrystalline silicon with multiply charged nanoclusters are studied that generate 'silicon clusters', i.e., nano-sized graded band gap structures. Multiply charged nanoclusters of manganese atoms strongly influence the photoelectric properties of monocrystalline silicon and expand the range of spectral sensitivity up to 8 μm; the photoelectric sensitivity reaches ∼10 9 . Conditions occur for the emergence of photo-emf in such a material in the infrared region when hν< E g . The obtained experimental data expand the functional capabilities for the application of silicon with multiply charged impurity atoms. (authors)

  17. Subharmonic energy-gap structure and heating effects in superconducting niobium point contacts

    DEFF Research Database (Denmark)

    Flensberg, K.; Hansen, Jørn Bindslev

    1989-01-01

    We present experimental data of the temperature-dependent subharmonic energy-gap structure (SGS) in the current-voltage (I-V) curves of superconducting niobium point contacts. The observed SGS is modified by heating effects. We construct a model of the quasiparticle conductance of metallic...... superconducting weak links that includes the heating effects self-consistently. Our model is combined with that of Octavio, Blonder, Klapwijk, and Tinkham [Phys. Rev. B 27, 6739 (1983)], which is based on the idea of multiple Andreev scattering in the contact. The shape and the temperature variation...

  18. The Development of Layered Photonic Band Gap Structures Using a Micro-Transfer Molding Technique

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, Kevin Jerome [Iowa State Univ., Ames, IA (United States)

    2001-06-27

    Over the last ten years, photonic band gap (PBG) theory and technology have become an important area of research because of the numerous possible applications ranging from high-efficiency laser diodes to optical circuitry. This research concentrates on reducing the length scale in the fabrication of layered photonic band gap structures and developing procedures to improve processing consistency. Various procedures and materials have been used in the fabrication of layered PBG structures. This research focused on an economical micro transfer molding approach to create the final PBG structure. A poly dimethylsiloxane (PDMS) rubber mold was created from a silicon substrate. It was filled with epoxy and built layer-by-layer to create a 3-D epoxy structure. This structure was infiltrated with nanoparticle titania or a titania sol-gel, then fired to remove the polymer mold, leaving a monolithic ceramic inverse of the epoxy structure. The final result was a lattice of titania rolds that resembles a face-centered tetragonal structure. The original intent of this research was to miniaturize this process to a bar size small enough to create a photonic band gap for wavelengths of visible electro-magnetic radiation. The factor limiting progress was the absence of a silicon master mold of small enough dimensions. The Iowa State Microelectronics Research Center fabricated samples with periodicities of 2.5 and 1.0 microns with the existing technology, but a sample was needed on the order of 0.3 microns or less. A 0.4 micron sample was received from Sandia National Laboratory, which was made through an electron beam lithography process, but it contained several defects. The results of the work are primarily from the 2.5 and 1.0 micron samples. Most of the work focused on changing processing variables in order to optimize the infiltration procedure for the best results. Several critical parameters were identified, ranging from the ambient conditions to the specifics of the

  19. Hierarchical structure for risk criteria applicable to nuclear power plants

    International Nuclear Information System (INIS)

    Hall, R.E.; Mitra, S.P.

    1985-01-01

    This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply. 5 refs., 2 figs

  20. Nuclear structure and double beta decay

    International Nuclear Information System (INIS)

    Vogel, P.

    1988-01-01

    Double beta decay is a rare transition between two nuclei of the same mass number A involving a change of the nuclear charge Z by two units. It has long been recognized that the Oν mode of double beta decay, where two electrons and no neutrinos are emitted, is a powerful tool for the study of neutrino properties. Its observation would constitute a convincing proof that there exists a massive Majorana neutrino which couples to electrons. Double beta decay is a process involving an intricate mixture of particle physics and physics of the nucleus. The principal nuclear physics issues have to do with the evaluation of the nuclear matrix elements responsible for the decay. If the authors wish to arrive at quantitative answers for the neutrino properties the authors have no choice but to learn first how to understand the nuclear mechanisms. The authors describe first the calculation of the decay rate of the 2ν mode of double beta decay, in which two electrons and two antineutrinos are emitted

  1. Nuclear Structures Surrounding Internal Lamin Invaginations

    Czech Academy of Sciences Publication Activity Database

    Legartová, Soňa; Stixová, Lenka; Laur, O.; Kozubek, Stanislav; Sehnalová, Petra; Bártová, Eva

    2014-01-01

    Roč. 115, č. 3 (2014), s. 476-487 ISSN 0730-2312 R&D Projects: GA MŠk(CZ) LD11020 Institutional support: RVO:68081707 Keywords : LAMINS * NUCLEAR PORES * CHROMATIN Subject RIV: BO - Biophysics Impact factor: 3.263, year: 2014

  2. Ageing evaluation model of nuclear reactors structural elements

    International Nuclear Information System (INIS)

    Ziliukas, A.; Jutas, A.; Leisis, V.

    2002-01-01

    In this article the estimation of non-failure probability by random faults on the structural elements of nuclear reactors is presented. Ageing is certainly a significant factor in determining the limits of nuclear plant lifetime or life extensions. Usually the non failure probability rates failure intensity, which is characteristic for structural elements ageing in nuclear reactors. In practice the reliability is increased incorrectly because not all failures are fixed and cumulated. Therefore, the methodology with using the fine parameter of the failures flow is described. The comparison of non failure probability and failures flow is carried out. The calculation of these parameters in the practical example is shown too. (author)

  3. Nuclear data for radiation damage estimates for reactor structural materials

    International Nuclear Information System (INIS)

    Piksaikin, V.

    1986-06-01

    The IAEA Consultants' Meeting on Nuclear Data for Radiation Damage Estimates for Reactor Structural Materials was convened by the IAEA Nuclear Data Section in Santa Fe, New Mexico, USA from 20-22 May 1985. The meeting was attended by 17 participants from 10 countries and 2 international organizations. The main objectives of the meeting were to review the status of displacement cross sections and the requirements for nuclear data needed for radiation damage estimates in reactor structural materials, and to develop recommendations for future activities in this field. This publication contains the text of all the papers prepared especially for this meeting including the conclusions and recommendations worked out during the meeting

  4. Report on aging of nuclear power plant reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States); Ellingwood, B.R. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering

    1996-03-01

    The Structural Aging Program provides the US Nuclear Regulatory Commission with potential structural safety issues and acceptance criteria for use in continued service assessments of nuclear power plant safety-related concrete structures. The program was organized under four task areas: Program Management, Materials Property Data Base, Structural Component Assessment/Repair Technology, and Quantitative Methodology for Continued Service Determinations. Under these tasks, over 90 papers and reports were prepared addressing pertinent aspects associated with aging management of nuclear power plant reinforced concrete structures. Contained in this report is a summary of program results in the form of information related to longevity of nuclear power plant reinforced concrete structures, a Structural Materials Information Center presenting data and information on the time variation of concrete materials under the influence of environmental stressors and aging factors, in-service inspection and condition assessments techniques, repair materials and methods, evaluation of nuclear power plant reinforced concrete structures, and a reliability-based methodology for current and future condition assessments. Recommendations for future activities are also provided. 308 refs., 61 figs., 50 tabs.

  5. Report on aging of nuclear power plant reinforced concrete structures

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1996-03-01

    The Structural Aging Program provides the US Nuclear Regulatory Commission with potential structural safety issues and acceptance criteria for use in continued service assessments of nuclear power plant safety-related concrete structures. The program was organized under four task areas: Program Management, Materials Property Data Base, Structural Component Assessment/Repair Technology, and Quantitative Methodology for Continued Service Determinations. Under these tasks, over 90 papers and reports were prepared addressing pertinent aspects associated with aging management of nuclear power plant reinforced concrete structures. Contained in this report is a summary of program results in the form of information related to longevity of nuclear power plant reinforced concrete structures, a Structural Materials Information Center presenting data and information on the time variation of concrete materials under the influence of environmental stressors and aging factors, in-service inspection and condition assessments techniques, repair materials and methods, evaluation of nuclear power plant reinforced concrete structures, and a reliability-based methodology for current and future condition assessments. Recommendations for future activities are also provided. 308 refs., 61 figs., 50 tabs

  6. Nuclear shapes and nuclear structure at low excitation energies. Abstracts of contributed papers

    International Nuclear Information System (INIS)

    Dykstra, F.; Goutte, D.; Sauvage, J.; Vergnes, M.

    1994-01-01

    103 papers are presented on recent theoretical and experimental results on nuclear structure investigation. Short communications were published in this volume, all of which were indexed separately for the INIS database. (R.P.)

  7. The study on the methods for improving the gredibility of NDT equipment for the gap of pellets of nuclear fuel rods

    International Nuclear Information System (INIS)

    Zhang Lei; Liu Ming; Wang Changhong; Ma Jinbo

    2014-01-01

    In order to improve the credibility of the new generation of automatic online non-destructive testing equipment for the gap of the pellets of nuclear fuel rods the researchers have done a lot of work in the development of the device. Such measures as multi-thread synchronization, precise timing, upper and lower computer communication control, antijamming processing are adopted such that the detecting device can accurately detecte the size of the gap between pellets, the position and length of the spring cavity at the front end of the nuclear fuel rods at a detection rate of 8 m/min. The detection credibility for the 0.5 mm gap is over 95%, reaching the international advanced level. At present, the device is put into use in the nuclear fuel element production line. (authors)

  8. Time-domain soil-structure interaction analysis of nuclear facilities

    International Nuclear Information System (INIS)

    Coleman, Justin L.; Bolisetti, Chandrakanth; Whittaker, Andrew S.

    2016-01-01

    The Nuclear Regulatory Commission (NRC) regulation 10 CFR Part 50 Appendix S requires consideration of soil-structure interaction (SSI) in nuclear power plant (NPP) analysis and design. Soil-structure interaction analysis for NPPs is routinely carried out using guidance provided in the ASCE Standard 4-98 titled “Seismic Analysis of Safety-Related Nuclear Structures and Commentary”. This Standard, which is currently under revision, provides guidance on linear seismic soil-structure-interaction (SSI) analysis of nuclear facilities using deterministic and probabilistic methods. A new appendix has been added to the forthcoming edition of ASCE Standard 4 to provide guidance for time-domain, nonlinear SSI (NLSSI) analysis. Nonlinear SSI analysis will be needed to simulate material nonlinearity in soil and/or structure, static and dynamic soil pressure effects on deeply embedded structures, local soil failure at the foundation-soil interface, nonlinear coupling of soil and pore fluid, uplift or sliding of the foundation, nonlinear effects of gaps between the surrounding soil and the embedded structure and seismic isolation systems, none of which can be addressed explicitly at present. Appendix B of ASCE Standard 4 provides general guidance for NLSSI analysis but will not provide a methodology for performing the analysis. This paper provides a description of an NLSSI methodology developed for application to nuclear facilities, including NPPs. This methodology is described as series of sequential steps to produce reasonable results using any time-domain numerical code. These steps require some numerical capabilities, such as nonlinear soil constitutive models, which are also described in the paper.

  9. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1991-01-01

    The research program of our group touches five areas of nuclear physics: (1) Nuclear structure studies at high spin; (2) Studies at the interface between structure and reactions; (3) Production and study of hot nuclei; (4) Incomplete fusion and fragmentation reactions; and (5) Development and use of novel techniques and instrumentation in the above areas of research. The papers from these areas are discussed in this report

  10. Nuclear structure investigations on spherical nuclei

    International Nuclear Information System (INIS)

    Heisenberg, J.; Calarco, J.; Dawson, J.; Hersman, F.W.

    1989-09-01

    This report discusses the following topics: electron scattering studies on spherical nuclei; electron scattering from collective states in deformed nuclei; proton and pion scattering studies; 12 C(e,e'p) and 16 O(e,e'p); 12 C(e,e'α) and 16 O(e,e'α); studies at high q at Bates; measurements with rvec e at Bates; 12 C(γ,p); future directions in giant resonance studies; proton knockout from 16 O; quasielastic studies at Bates; triple coincidence studies of nuclear correlations; contributions to (e,e'2p) at KIKHEF; contributions to instrumentation at CEBAF; instrumentation development at UNH; the Bates large acceptance spectrometer toroid; shell model and core polarization calculations; and the relativistic nuclear model

  11. Nuclear microscopy of sperm cell elemental structure

    Energy Technology Data Exchange (ETDEWEB)

    Bench, G.S.; Balhorn, R.; Friz, A.M.; Freeman, S.P.H.T.

    1994-09-28

    Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. Nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the amount of phosphorus and sulfur, the total DNA and protamine content in individual sperm from fertile bull and mouse semen have been determined. These values agree with results obtained from other biochemical analyses. Nuclear microscopy shows promise for measuring elemental profiles in the chromatin of individual sperm. The technique may be able to resolve theories regarding the importance of protamines to male fertility and identify biochemical defects responsible for certain types of male infertility.

  12. The nuclear structure and low-energy reactions (NSLER) collaboration

    International Nuclear Information System (INIS)

    Dean, D J

    2006-01-01

    The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible

  13. Nuclear structure of Ra at high spin

    Indian Academy of Sciences (India)

    to such an aligned configuration in 216Ra, would be of the order of J ∼ 39 ¯h with a wave function of π(h2. 9/2 f 2 ... detectors at 99. ◦. In addition to these matrices, γ-gated γT matrices were generated for getting time spectrum between any two γ's of 216Ra which enabled lifetime measurement of isomeric nuclear levels. 3.

  14. Quantum field theory and nuclear structure

    International Nuclear Information System (INIS)

    Celenza, L.S.; Goulard, B.; Shakin, C.M.

    1981-01-01

    We discuss recent successful calculations of the properties of nuclear matter within the context of theories exhibiting mass generation through spontaneous symmetry breaking. We start with the sigma model of Gell-Mann and Levy and introduce the nucleon mass (in a vacuum) in the usual manner. We relate the expectation value of the sigma field in a vacuum to a finite value of the scalar density. If the vacuum is now filled with nucleons (nuclear matter) the scalar density is increased and the new value for the nucleon mass must be determined. We exhibit the equation whose solution determines the new mass, and we also define a perturbative scheme for the determination of this mass. This scheme involves an expansion of the various quantities of the theory in terms of matrix elements calculated with positive- and negative-energy spinors parametrized with the vacuum mass. Although the decrease in the mass upon going from vacuum to nuclear matter at the equilibrium density is quite large (approx.400 MeV), we are still able to exhibit a small parameter which allows for a perturbative expansion of the binding energy and other observables. The leading term in such an expansion reproduces the approximation widely used in other calculations of the properties of nuclear matter. The truncation of the expansion at the leading term is inadequate and this fact accounts for the lack of success in previous calculations using the standard formalism. We proceed to make a transformation to the Weinberg Lagrangian retaining the fluctuating parts of the sigma field. We further make a small-oscillation approximation, dropping the nonlinear terms in this Lagrangian

  15. X-band photonic band-gap accelerator structure breakdown experiment

    Directory of Open Access Journals (Sweden)

    Roark A. Marsh

    2011-02-01

    Full Text Available In order to understand the performance of photonic band-gap (PBG structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz. The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65  MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110  MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100  MV/m and a surface magnetic field of 890  kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14  MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  16. Atomic parity nonconservation: Electroweak parameters and nuclear structure

    International Nuclear Information System (INIS)

    Pollock, S.J.; Fortson, E.N.; Wilets, L.

    1992-01-01

    There have been suggestions to measure atomic parity nonconservation (PNC) along an isotopic chain, by taking ratios of observables in order to cancel complicated atomic-structure effects. Precise atomic PNC measurements could make a significant contribution to tests of the standard model at the level of one-loop radiative corrections. However, the results also depend upon certain features of nuclear structure, such as the spatial distribution of neutrons in the nucleus. To examine the sensitivity to nuclear structure, we consider the case of Pb isotopes using various recent relativistic and nonrelativistic nuclear model calculations. Contributions from nucleon internal weak structure are included, but found to be fairly negligible. The spread among present models in predicted sizes of nuclear-structure effects may preclude using Pb isotope ratios to test the standard model at better than a 1% level, unless there are adequate independent tests of the nuclear models by various alternative strong and electroweak nuclear probes. On the other hand, sufficiently accurate atomic PNC experiments would provide a unique method to measure neutron distributions in heavy nuclei

  17. Nuclear reactor structural material forming less radioactive corrosion product

    International Nuclear Information System (INIS)

    Nakazawa, Hiroshi.

    1988-01-01

    Purpose: To provide nuclear reactor structural materials forming less radioactive corrosion products. Constitution: Ni-based alloys such as inconel alloy 718, 600 or inconel alloy 750 and 690 having excellent corrosion resistance and mechanical property even in coolants at high temperature and high pressure have generally been used as nuclear reactor structural materials. However, even such materials yield corrosion products being attacked by coolants circulating in the nuclear reactor, which produce by neutron irradiation radioactive corrosion products, that are deposited in primary circuit pipeways to constitute exposure sources. The present invention dissolves dissolves this problems by providing less activating nuclear reactor structural materials. That is, taking notice on the fact that Ni-58 contained generally by 68 % in Ni changes into Co-58 under irradiation of neutron thereby causing activation, the surface of nuclear reactor structural materials is applied with Ni plating by using Ni with a reduced content of Ni-58 isotopes. Accordingly, increase in the radiation level of the nuclear reactor structural materials can be inhibited. (K.M.)

  18. Influence of the precursors in the morphology, structure, vibrational order and optical gap of nano structured Zn O

    Energy Technology Data Exchange (ETDEWEB)

    Jurado, J. F.; Londono C, A.; Jurado L, F. F.; Romero S, J. D., E-mail: jfjurado@unal.edu.co [Universidad Nacional de Colombia, Laboratorio de Propiedades Termicas Dielectricas de Compositos, A. A. 127, Manizales (Colombia)

    2014-07-01

    The synthesis of Zn O by reaction in solid state from two precursor salts (zinc acetate and zinc sulfate), presented significant differences concerning morphology, structure, vibrational order and optical gap. As well as covering in the size of the compounds, a homogeneous distribution of nanoparticles of 21±3 nm and micro stars of 1.03±0.19 μm respectively. The Zn O showed a structural phase with a vibrational state of the hexagonal type (wurtzite). The variation in the morphology due to the precursor is attributed to the disorder within of lattice, which contributes to vibrational changes and is correlated to the degrees of freedom of molecules. Measurements of UV-Vis of nanoparticles displayed a band gap (E{sub g}) lower than the one reported for the bulk material. The structural characterization of the compounds was carried out by using a X-ray Bruker D8 Advance diffractometer. The vibrational order was assessed throughout micro-Raman with a monochromatic radiation source of 473 nm). (Author)

  19. Observation of wakefields in a beam-driven photonic band gap accelerating structure

    Directory of Open Access Journals (Sweden)

    C. Jing

    2009-12-01

    Full Text Available Wakefield excitation has been experimentally studied in a three-cell X-band standing wave photonic band gap (PBG accelerating structure. Major monopole (TM_{01}- and TM_{02}-like and dipole (TM_{11}- and TM_{12}-like modes were identified and characterized by precisely controlling the position of beam injection. The quality factor Q of the dipole modes was measured to be ∼10  times smaller than that of the accelerating mode. A charge sweep, up to 80 nC, has been performed, equivalent to ∼30  MV/m accelerating field on axis. A variable delay low charge witness bunch following a high charge drive bunch was used to calibrate the gradient in the PBG structure by measuring its maximum energy gain and loss. Experimental results agree well with numerical simulations.

  20. Nuclear structure at high-spin and large-deformation

    International Nuclear Information System (INIS)

    Shimizu, Yoshifumi R.

    2000-01-01

    Atomic nucleus is a finite quantal system and shows various marvelous features. One of the purposes of the nuclear structure study is to understand such features from a microscopic viewpoint of nuclear many-body problem. Recently, it is becoming possible to explore nuclear states under 'extreme conditions', which are far different from the usual ground states of stable nuclei, and new aspects of such unstable nuclei attract our interests. In this lecture, I would like to discuss the nuclear structure in the limit of rapid rotation, or the extreme states with very large angular momenta, which became accessible by recent advent of large arrays of gamma-ray detecting system; these devices are extremely useful to measure coincident multiple γ-rays following heavy-ion fusion reactions. Including such experimental aspects as how to detect the nuclear rotational states, I review physics of high-spin states starting from the elementary subjects of nuclear structure study. In would like also to discuss the extreme states with very large nuclear deformation, which are easily realized in rapidly rotating nuclei. (author)

  1. High power breakdown testing of a photonic band-gap accelerator structure with elliptical rods

    Directory of Open Access Journals (Sweden)

    Brian J. Munroe

    2013-01-01

    Full Text Available An improved single-cell photonic band-gap (PBG structure with an inner row of elliptical rods (PBG-E was tested with high power at a 60 Hz repetition rate at X-band (11.424 GHz, achieving a gradient of 128  MV/m at a breakdown probability of 3.6×10^{-3} per pulse per meter at a pulse length of 150 ns. The tested standing-wave structure was a single high-gradient cell with an inner row of elliptical rods and an outer row of round rods; the elliptical rods reduce the peak surface magnetic field by 20% and reduce the temperature rise of the rods during the pulse by several tens of degrees, while maintaining good damping and suppression of high order modes. When compared with a single-cell standing-wave undamped disk-loaded waveguide structure with the same iris geometry under test at the same conditions, the PBG-E structure yielded the same breakdown rate within measurement error. The PBG-E structure showed a greatly reduced breakdown rate compared with earlier tests of a PBG structure with round rods, presumably due to the reduced magnetic fields at the elliptical rods vs the fields at the round rods, as well as use of an improved testing methodology. A post-testing autopsy of the PBG-E structure showed some damage on the surfaces exposed to the highest surface magnetic and electric fields. Despite these changes in surface appearance, no significant change in the breakdown rate was observed in testing. These results demonstrate that PBG structures, when designed with reduced surface magnetic fields and operated to avoid extremely high pulsed heating, can operate at breakdown probabilities comparable to undamped disk-loaded waveguide structures and are thus viable for high-gradient accelerator applications.

  2. Analytical and Numerical Calculations of Two-Dimensional Dielectric Photonic Band Gap Structures and Cavities for Laser Acceleration

    CERN Document Server

    Samokhvalova, Ksenia R; Liang Qian, Bao

    2005-01-01

    Dielectric photonic band gap (PBG) structures have many promising applications in laser acceleration. For these applications, accurate determination of fundamental and high order band gaps is critical. We present the results of our recent work on analytical calculations of two-dimensional (2D) PBG structures in rectangular geometry. We compare the analytical results with computer simulation results from the MIT Photonic Band Gap Structure Simulator (PBGSS) code, and discuss the convergence of the computer simulation results to the analytical results. Using the accurate analytical results, we design a mode-selective 2D dielectric cylindrical PBG cavity with the first global band gap in the frequency range of 8.8812 THz to 9.2654 THz. In this frequency range, the TM01-like mode is shown to be well confined.

  3. International symposium on exotic nuclear structures. Book of abstracst

    International Nuclear Information System (INIS)

    2000-01-01

    The following topics were discussed at the meeting: Physics of weakly bound nuclei, neutron skin and halo; Evolution of shell structures for neutron-rich nuclei; Collective excitations in nuclei with exotic nuclear shapes; Cluster structures; Super- and hyperdeformed nuclei, exotic structures in the actinides; Superheavy elements; Towards understanding the structure of nucleons; New experimental techniques, facilities for radioactive beams. All abstracts (75 items) were submitted as full text to the INIS database. (R.P.)

  4. K isomers as probes of nuclear structure

    Science.gov (United States)

    Tandel, S. K.

    2014-08-01

    K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

  5. K isomers as probes of nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Tandel, S. K., E-mail: sujit.tandel@cbs.ac.in [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India)

    2014-08-14

    K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

  6. Dispersive and resonant properties of finite one-dimensional photonic band gap structures

    Science.gov (United States)

    Bowden, C. M.; Scalora, Michael; Bloemer, Mark J.; Sibilia, Concita; D'Aguanno, Giuseppe; Centini, Marco; Bertolotti, Mario

    2000-06-01

    The report is a review of work one-dimensional photonic band gap (PBG) materials, carried out by the Quantum Optics Group at the US Army Aviation and Missile Command during the past few years. This work has benefited from national and international collaborations between academic, industrial, and governmental research organizations. The research effort has benefited from a multifaceted approach that combined innovative, theoretical methods with fabrication techniques in order to address the physics of structures of finite length, i.e., the description of spatio-temporal linear and nonlinear dynamics and boundary conditions. In this work we will review what we consider three major breakthroughs: (a) the discovery of transparent metals; (b) discovery of critical phase matching conditions in PBG structures for second harmonic and nonlinear frequency conversion; (c) development of a PBG true time delay device. Our report addresses linear and nonlinear wave propagation in PBG materials, one-dimensional structures in particular. Most investigators generally address two and three-dimensional structures. We choose one-dimensional systems because in the past they have proven to be quite challenging and have pointed the way to the new physical phenomena that are the subject of this report. In addition, one-dimensional systems can be used as a blueprint for higher dimensional structures, where the work is necessarily much more computationally intensive, and the physics much less transparent as a result.

  7. Diffusion-advection within dynamic biological gaps driven by structural motion

    Science.gov (United States)

    Asaro, Robert J.; Zhu, Qiang; Lin, Kuanpo

    2018-04-01

    To study the significance of advection in the transport of solutes, or particles, within thin biological gaps (channels), we examine theoretically the process driven by stochastic fluid flow caused by random thermal structural motion, and we compare it with transport via diffusion. The model geometry chosen resembles the synaptic cleft; this choice is motivated by the cleft's readily modeled structure, which allows for well-defined mechanical and physical features that control the advection process. Our analysis defines a Péclet-like number, AD, that quantifies the ratio of time scales of advection versus diffusion. Another parameter, AM, is also defined by the analysis that quantifies the full potential extent of advection in the absence of diffusion. These parameters provide a clear and compact description of the interplay among the well-defined structural, geometric, and physical properties vis-a ̀-vis the advection versus diffusion process. For example, it is found that AD˜1 /R2 , where R is the cleft diameter and hence diffusion distance. This curious, and perhaps unexpected, result follows from the dependence of structural motion that drives fluid flow on R . AM, on the other hand, is directly related (essentially proportional to) the energetic input into structural motion, and thereby to fluid flow, as well as to the mechanical stiffness of the cleftlike structure. Our model analysis thus provides unambiguous insight into the prospect of competition of advection versus diffusion within biological gaplike structures. The importance of the random, versus a regular, nature of structural motion and of the resulting transient nature of advection under random motion is made clear in our analysis. Further, by quantifying the effects of geometric and physical properties on the competition between advection and diffusion, our results clearly demonstrate the important role that metabolic energy (ATP) plays in this competitive process.

  8. Status of the evaluated nuclear structure data file

    International Nuclear Information System (INIS)

    Martin, M.J.

    1991-01-01

    The structure, organization, and contents of the Evaluated Nuclear Structure Data File (ENSDF) are discussed in this paper. This file contains a summary of the state of experimental nuclear structure data for all nuclides as determined from consideration of measurements reported worldwide in the literature. Special emphasis is given to the data evaluation procedures, the consistency checks, and the quality control utilized at the input stage and to the retrieval capabilities of the system at the output stage. Recent enhancements of the on-line interaction with the file contents is addressed as well as procedural changes that will improve the currency of the file

  9. Structuring Cooperative Nuclear RIsk Reduction Initiatives with China.

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Larry [Stanford Univ., CA (United States); Reinhardt, Jason Christian [Stanford Univ., CA (United States); Hecker, Siegfried [Stanford Univ., CA (United States)

    2017-03-01

    The Stanford Center for International Security and Cooperation engaged several Chinese nuclear organizations in cooperative research that focused on responses to radiological and nuclear terrorism. The objective was to identify joint research initiatives to reduce the global dangers of such threats and to pursue initial technical collaborations in several high priority areas. Initiatives were identified in three primary research areas: 1) detection and interdiction of smuggled nuclear materials; 2) nuclear forensics; and 3) radiological (“dirty bomb”) threats and countermeasures. Initial work emphasized the application of systems and risk analysis tools, which proved effective in structuring the collaborations. The extensive engagements between national security nuclear experts in China and the U.S. during the research strengthened professional relationships between these important communities.

  10. 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

  11. The structure of nuclear safeguards systems

    International Nuclear Information System (INIS)

    Coulter, C.A.

    1989-01-01

    Safeguards systems for facilities that handle special nuclear material combine procedural, protective, and materials accounting elements to prevent and/or detect sabotage and diversion or theft of material. Because most of the discussion in this course is devoted to materials accounting topics only, this chapter provides a brief introduction to some of the procedural and protective elements of safeguards systems, placing the materials accounting system in its proper context. The chapter begins by reviewing certain pertinent DOE definitions and then surveys some protection requirements and technology - protective personnel, personnel identification systems, barriers, detectors, and communication systems. Considered next are the procedures of personnel selection and monitoring, definition and division of job functions, and operation. The chapter then describes the way the procedural, protective, and materials accounting elements can be combined, becoming a total safeguards system. Although such a system necessarily requires elements of procedure, protection, and materials accounting, only the materials accounting gives positive assurance that nuclear material is not diverted or stolen

  12. Micro-structured nuclear fuel and novel nuclear reactor concepts for advanced power production

    International Nuclear Information System (INIS)

    Popa-Simil, Liviu

    2008-01-01

    Many applications (e.g. terrestrial and space electric power production, naval, underwater and railroad propulsion and auxiliary power for isolated regions) require a compact-high-power electricity source. The development of such a reactor structure necessitates a deeper understanding of fission energy transport and materials behavior in radiation dominated structures. One solution to reduce the greenhouse-gas emissions and delay the catastrophic events' occurrences may be the development of massive nuclear power. The actual basic conceptions in nuclear reactors are at the base of the bottleneck in enhancements. The current nuclear reactors look like high security prisons applied to fission products. The micro-bead heterogeneous fuel mesh gives the fission products the possibility to acquire stable conditions outside the hot zones without spilling, in exchange for advantages - possibility of enhancing the nuclear technology for power production. There is a possibility to accommodate the materials and structures with the phenomenon of interest, the high temperature fission products free fuel with near perfect burning. This feature is important to the future of nuclear power development in order to avoid the nuclear fuel peak, and high price increase due to the immobilization of the fuel in the waste fuel nuclear reactor pools. (author)

  13. PREFACE: Structure of Exotic Nuclei and Nuclear Forces

    Science.gov (United States)

    Honma, Michio; Otsuka, Takaharu; Aoi, Nori

    2006-11-01

    The International Symposium on `Structure of Exotic Nuclei and Nuclear Forces' was held at The Koshiba Hall, University of Tokyo, on 9 - 12 March 2006. This symposium was organized as an activity of the Grant-in-Aid for the specially promoted area `Monte Carlo Shell Model' from the Ministry of Education, Science, Sports and Culture (MEXT) of Japan. The symposium was sponsored by the Center for Nuclear Study (CNS) and by RIKEN. The purpose of the symposium was to discuss theoretical and experimental developments in the study of the structure of exotic nuclei and its relationship with nuclear forces. There has been much progress recently in our understanding of what the structure of exotic nuclei is and how it can be linked to nuclear forces, with emerging intriguing perspectives. The following subjects were covered in this symposium Present status and future of the shell model Effective interaction theories Experimental results and perspectives Few-body methods including ab initio calculations Advancements of mean-fieeld models Transition between shell and cluster structure Nuclear astrophysics and nuclear structure Particle physics and the shell model Emphasis was placed on the interplay between many-body structures and nuclear forces, and on the experimental clarification of these topics. Around 80 participants attended the symposium and we enjoyed 34 excellent and lively invited talks and 26 oral presentations. The organizing committee consisted of B A Brown (MSU), S Fujii (CNS), M Honma (Aizu), T Kajino (NAO), T Mizusaki (Senshu), T Motobayashi (RIKEN), K Muto (TIT), T Otsuka (Chair, Tokyo/CNS/RIKEN), P Ring (TMU), N Shimizu (Scientific Secretary, Tokyo), S Shimoura (CNS), Y Utsuno (Scientific Secretary, JAEA). Finally, we would like to thank all the speakers and the participants as well as the other organizers for their contributions which made the symposium so successful.

  14. ISINN-2. Neutron spectroscopy, nuclear structure and related topics

    International Nuclear Information System (INIS)

    1994-01-01

    The proceedings contain the materials presented at the Second International Seminar on Neutron-Nucleus Interactions (ISINN-2) dealing with the problems of neutron spectroscopy, nuclear structure and related topics. The Seminar took place in Dubna on April 26-28, 1994. Over 120 scientists from Belgium, Bulgaria, Czech Republic, Germany, Holland, Italy, Japan, Latvia, Mexico, Poland, Slovakia, Slovenia, Ukraine, US and about 10 Russian research institutes took part in the Seminar. The main problems discussed are the following: P-odd and P-even angular correlation and T-reversal invariance in neutron reactions, nuclear structure investigations by neutron capture, the mechanism of neutron reactions, nuclear fission processes, as well as neutron data for nuclear astrophysics

  15. Temperature evolution of subharmonic gap structures in MgB{sub 2}/Nb point-contacts

    Energy Technology Data Exchange (ETDEWEB)

    Giubileo, F. [CNR-INFM Laboratorio Regionale SUPERMAT e Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, via Salvador Allende, 84081 Baronissi (Italy)], E-mail: giubileo@sa.infn.it; Bobba, F.; Scarfato, A.; Piano, S. [CNR-INFM Laboratorio Regionale SUPERMAT e Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, via Salvador Allende, 84081 Baronissi (Italy); Aprili, M. [Laboratoire de Spectroscopie en Lumiere Polarisee, ESPCI, 10 rue Vauquelin, 75005 Paris (France); CSNSM-CNRS, Bat. 108 Universite Paris-Sud, 91405 Orsay (France); Cucolo, A.M. [CNR-INFM Laboratorio Regionale SUPERMAT e Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, via Salvador Allende, 84081 Baronissi (Italy)

    2007-09-01

    We have performed point-contact spectroscopy experiments on superconducting micro-constrictions between Nb tips and high quality MgB{sub 2} pellets. We measured the temperature evolution (between 4.2 K and 300 K) of the current-voltage (I-V) and of the dynamical conductance (dI/dV-V) characteristics. Above the Nb critical temperature T{sub C}{sup Nb}, the conductance of the constrictions behaves as predicted by the BTK model for S/N contacts being Nb in its normal state below T{sub C}{sup Nb}, the contacts show Josephson current and subharmonic gap structures, due to multiple Andreev reflections. These observations clearly indicate the coupling of the MgB{sub 2} 3D {pi}-band with the Nb superconducting order parameter. We found {delta}{sub {pi}} = 2.4 {+-} 0.2 meV for the three-dimensional gap of MgB{sub 2}.

  16. Heterointerface engineering of broken-gap InAs/GaSb multilayer structures.

    Science.gov (United States)

    Liu, Jheng-Sin; Zhu, Yan; Goley, Patrick S; Hudait, Mantu K

    2015-02-04

    Broken-gap InAs/GaSb strain balanced multilayer structures were grown by molecular beam epitaxy (MBE), and their structural, morphological, and band alignment properties were analyzed. Precise shutter sequence during the MBE growth process, enable to achieve the strain balanced structure. Cross-sectional transmission electron microscopy exhibited sharp heterointerfaces, and the lattice line extended from the top GaSb layer to the bottom InAs layer. X-ray analysis further confirmed a strain balanced InAs/GaSb multilayer structure. A smooth surface morphology with surface roughness of ∼0.5 nm was demonstrated. The effective barrier height -0.15 eV at the GaSb/InAs heterointerface was determined by X-ray photoelectron spectroscopy, and it was further corroborated by simulation. These results are important to demonstrate desirable characteristics of mixed As/Sb material systems for high-performance and low-power tunnel field-effect transistor applications.

  17. Fabrication and cold test of photonic band gap resonators and accelerator structures

    Directory of Open Access Journals (Sweden)

    Evgenya I. Smirnova

    2005-09-01

    Full Text Available We present the detailed description of the successful design and cold test of photonic band gap (PBG resonators and traveling-wave accelerator structures. Those tests provided the essential basis for later hot test demonstration of the first PBG accelerator structure at 17.140 GHz [E. I. Smirnova, A. S. Kesar, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, Phys. Rev. Lett., 95, 074801 (2005.PRLTAO0031-900710.1103/PhysRevLett.95.074801]. The advantage of PBG resonators is that they were built to support only the main, TM_{01}-like, accelerator mode while not confining the higher-order modes (HOM or wakefields. The design of the PBG resonators was based on a triangular lattice of rods, with a missing rod at the center. Following theoretical analysis, the rod radius divided by the rod spacing was held to a value of about 0.15 to avoid supporting HOM. For a single-cell test the PBG structure was fabricated in X-band (11 GHz and brazed. The mode spectrum and Q factor (Q=5 000 agreed well with theory. Excellent HOM suppression was evident from the cold test. A six-cell copper PBG accelerator traveling-wave structure with reduced long-range wakefields was designed and was built by electroforming at Ku-band (17.140 GHz. The structure was tuned by etching the rods. Cold test of the structure yielded excellent agreement with the theoretical design. Successful results of the hot test of the structure demonstrating the acceleration of the electron beam were published in E. I. Smirnova, A. S. Kesar, I. Mastovsky, M. A. Shapiro, and R. J. Temkin, Phys. Rev. Lett., 95, 074801 (2005.PRLTAO0031-900710.1103/PhysRevLett.95.074801

  18. Structural integrity of materials in nuclear service: a bibliography

    International Nuclear Information System (INIS)

    Heddleson, F.A.

    1977-01-01

    This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user

  19. Structural integrity of materials in nuclear service: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Heddleson, F.A.

    1977-06-07

    This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user.

  20. RATU - Nuclear power plant structural safety

    International Nuclear Information System (INIS)

    Hedner, G.; Schultz, H.; Unneberg, L.

    1992-12-01

    The evaluation group is of the opinion that the work performed under the RATU programme is generally of high quality, in some areas, especially those related to water chemistry of excellent quality. The personnel gives the impression of being dedicated and enthusiastic, and the administration seems to be very effective. It is obvious that the RATU programme has taken advantage of related contracts and projects funded by different sources. It is the opinion of the valuation group that the investment and human capital have been brought to work very efficiently in all projects. The objectives of the programme and the different projects are formulated in a broad sense. The areas selected for work are however of high relevance to nuclear safety. In some projects not all aspects are addressed by the ongoing work, and further activities may be necessary to meet with the requirements of the authorities. (orig.)

  1. Structural dynamic and resistance to nuclear air blast

    International Nuclear Information System (INIS)

    Qureshi, S.M.

    2003-01-01

    A need exists to design protective shelters attached to specialized facilities against nuclear airbursts, explosive shocks and impacting projectiles. Designing such structures against nuclear and missile impact is a challenging task that needs to be looked into for design methodology formulation and practicability. Structures can be designed for overpressure pulsed generated by a nuclear explosion as well as the scabbing and perforation/punching of an impacting projectile. This paper discuses and formulates the methods of dynamic analysis and design required to undertake such a task. Structural resistance to peak overpressure pulse for a 20 KT weapons and smaller tactical nuclear weapons of 1 KT (16 psi, overpressure) size as a direct air blast overpressure has been considered in design of walls, beams and slabs of a special structure under review. The design of shear reinforcement as lacing is also carried out. Adopting the philosophy of strengthening and hardening can minimize the effect of air blast overpressure and projectile impact. The objective is to avoid a major structural failure. The structure then needs to be checked against ballistic penetration by a range of weapons or be required to resist explosive penetration from the charge detonated in contact with the structure. There is also a dire need to formulate protective guidelines for all existing and future critical facilities. (author)

  2. The policy structure of the Dutch nuclear energy sector

    International Nuclear Information System (INIS)

    Zijlstra, G.J.

    1982-01-01

    The main objective of this study has been to indicate the principle structures through which much of governmental nuclear policy is formed and to develop a model for the analysis of policy communication networks. The first chapter begins with a general outline of the international development of nuclear energy and gives an impression of the Dutch nuclear energy sector with special emphasis on the institutional aspects. In chapter II the author elaborates on the place of structural analysis in public policy analysis and argues that it is one of the indispensable elements of public policy analysis. Relations are treated in chapter III. Personal interlocks are given special attention because these are interrelated with financial, informational and other dependency relations and have a special communicative function in public policy-making. The different functions of the interlocks are 'translated' in graph theoretical concepts. Chapter IV introduces a method derived from graph analysis to analyse public policy networks. Several structural configurations are distinguished. In the same chapter an outline of the empirical research on the nuclear energy network will be given. In chapters V and VI the nuclear energy network is analysed, and in chapter VII the decision-making concerning some nuclear items is described in a general way. (Auth.)

  3. Online Monitoring of Concrete Structures in Nuclear Power Plants: Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Sankaran [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cai, Guowei [Idaho National Lab. (INL), Idaho Falls, ID (United States); Agarwal, Vivek [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    The existing fleet of nuclear power plants in the United States have initial operating licenses of 40 years, and many of these plants have applied for and received license extensions. As plant structures, systems, and components age, their useful life—considering both structural integrity and performance—is reduced as a result of deterioration of the materials. Assessment and management of aging concrete structures in nuclear plants require a more systematic approach than simple reliance on existing code-based design margins of safety. Structural health monitoring is required to produce actionable information regarding structural integrity that supports operational and maintenance decisions. The online monitoring of concrete structures project conducted under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability program at Idaho National Laboratory is seeking to develop and demonstrate capabilities for concrete structures health monitoring. Through this research project, several national laboratories and Vanderbilt University propose to develop a framework of research activities for the health monitoring of nuclear power plant concrete structures that includes the integration of four elements—damage modeling, monitoring, data analytics, and uncertainty quantification. This report briefly discusses activities in this project during October-December, 2014. The most significant activity during this period was the organizing of a two-day workshop on research needs in online monitoring of concrete structures, hosted by Vanderbilt University in November 2014. Thirty invitees from academia, industry and government participated in the workshop. The presentations and discussions at the workshop surveyed current activities related to concrete structures deterioration modeling and monitoring, and identified the challenges, knowledge gaps, and opportunities for advancing the state of the art; these

  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. Nuclear structure of light Ca and heavy Cr isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, A.

    2007-07-01

    -energy Coulomb excitation of radioactive beams. Prior to this experiment, the assumption of a sub-shell closure was based only on systematics of excitation energies of the first 2{sup +} states in Cr, Ti, and Ca isotopes. The small B(E2) value for {sup 56}Cr is in agreement with these indications. Further evidence for a N=32 shell gap has meanwhile been found in the development of B(E2) values in Ti isotopes and the evolution of E(4{sup +})/E(2{sup +}) ratios for Cr and Ti. While the experimental evidence has firmly established a sub-shell closure at N=32, calculations are, at present, not able to reproduce the behavior of the B(E2) values, whereas the evolution of excitation energies is well described. Both results touch the limits of present nuclear structure models: in the Cr isotopes, the B(E2) evolution cannot yet be reproduced, and in the Ca isotopes, a consistent picture of mirror energy differences as well as a successful calculation of cross sections are missing. As a result of this work, new experimental data are available for future improvements of such calculations. (orig.)

  6. Nuclear structure at intermediate energies. Progress report

    International Nuclear Information System (INIS)

    Bonner, B.E.; Mutchler, G.S.

    1992-01-01

    We report here oil the progress that we made for the nine months beginning October 1, 1991 for DOE Grant No. DE-FG05-87ER40309. The report covers the third year of a three year grant. Since we are submitting an accompanying Grant Renewal Proposal, we provide in this report more background information than usual for the different projects. The theme that unites the experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of AGS bar p experiment E854, AGS heavy ion experiment E810, as-well as the approved STAR experiment at RHIC), - all these projects share this common goal. FNAL E683 may well open a new field of investigation in nuclear physics: That of just how colored quarks and gluons interact with nuclear matter as they traverse nuclei of different-sizes. In most all of the experiments mentioned, above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are available to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do. The format we follow in the Progress Report is,to provide a concise, but fairly complete write-up on each project. The publications listed in Section In give much greater detail on many of the projects. The aim in this report is to focus on the physics goals, the results, and their significance

  7. Development of deterioration models and tests of structural materials for nuclear containment structures(III)

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Byung Hwan [Seoul National University, Seoul (Korea)

    2002-03-01

    The nuclear containment structures are very important infrastructures which require much cost for construction and maintenance. If these structures lose their functions and do not ensure their safety, great losses of human lives and properties will result. Therefore, the nuclear containment structures should secure appropriate safety and functions during these service lives. The nuclear concrete structures start to experience deterioration due to severe environmental condition, even though the concrete structures exhibit generally superior durability. It is, therefore, necessary to take appropriate actions at each stage of planning, design and construction to secure safety and functionability. Thorough examination of deterioration mechanism and comprehensive tests have been conducted to explore the durability characteristics of nuclear concrete structures. 88 refs., 70 figs., 12 tabs. (Author)

  8. Nuclear structure and Indian Clover array

    Indian Academy of Sciences (India)

    The experimental Й t values lie somewhere halfway between the values obtained for these two minima. Thus, the present work showed for the first time an oblate shape for Kr at low spins and a triaxial shape at higher spins. 6. Shape of. ¼. Kr at high spin. The shape and structure of. ¼. Kr at high spins has also been studied ...

  9. Organization, structure, and performance in the US nuclear power industry

    International Nuclear Information System (INIS)

    Lester, R.K.

    1986-01-01

    Several propositions are advanced concerning the effects of industry organization and structure on the economic performance of the American commercial nuclear power industry. Both the electric utility industry and the nuclear power plant supply industry are relatively high degree of horizontal disaggregation. The latter is also characterized by an absence of vertical integration. The impact of each of these factors on construction and operating performance is discussed. Evidence is presented suggesting that the combination of horizontal and vertical disaggregation in the industry has had a significant adverse effect on economic performance. The relationship between industrial structure and regulatory behavior is also discussed. 43 references, 4 figures, 9 tables

  10. Superluminary relativity related to nuclear forces and structures

    International Nuclear Information System (INIS)

    Anastasovski, Petar K.

    1998-01-01

    The new Theory of Superluminary Relativity (SLR) presented and proposed here is based on the superluminary frame of reference transformation and on the modified principles of Special Relativity, General Relativity and Quantum Mass Theory. One of the main concepts of the SLR theory is application of Newton's law of universal gravitation to nuclear structures. The constant in the Newton's gravitational magnitudes for distances and masses characteristic for nuclear structures is defined and determined by the Quantum Mass Theory. The analysis is performed for a nucleus with two nucleons, that is for the deuteron nucleus. On the bases of the principles of Superluminary Relativity a new deuteron nucleus model is offered. (author)

  11. Experimental investigations of the nuclear structure

    International Nuclear Information System (INIS)

    Gromov, K.Ya.

    1989-01-01

    The problem of experimental investigation into atomic nucleus structure is discussed. Examples of studying the properties of low-lying nucleus states using cyclotron-type accelerators for their production are presented. The consideration is conducted on the base of the Idisol experimental complex created at the Finland. Results of measuring masses of neutron-redundant rubidium nuclei are presented. Schemes of 160 Er and 108 In decay are presented. 12 refs.; 6 figs

  12. The role of nuclear shapes in nuclear structure (from the perspective of the Daresbury Tandem)

    International Nuclear Information System (INIS)

    Nazarewicz, W.

    1993-01-01

    In specific regions of the nuclear periodic chart, large multipole moments are observed and the low-lying excitations have a rotational character. These features are understood if the nuclei in question are assumed to have a stable deformation, i.e., a non-spherical distribution of the nuclear matter. In other (transitional) regions the quasi-rotational bands are present; they are strongly coupled to low-lying vibrational modes. Those nuclei are best understood in terms of small static deformations but large dynamic fluctuations around local equilibria. As a matter of fact, the vast majority of nuclei are deformed; even in those which are spherical or almost spherical, the dynamical couplings to shape vibrations are crucial. The issue of nuclear deformation is many-faceted. If the nuclear shape (nuclear mean field) is deformed, characteristic excitation modes are present, such as rotations and vibrations built upon the non-spherical equilibrium. Through the particle-core coupling, nuclear deformations can dramatically influence the single-particle properties of nucleons moving in the average nuclear potential. Many experimental investigations using the Daresbury Tandem were related in one way or another to the physics of nuclear shapes. Fundamental discoveries from Daresbury include the observation of superdeformed structures in rapidly rotating nuclei, the observation of identical (open-quotes twinnedclose quotes) rotational bands, various studies of structural changes induced by very fast rotation (band-crossings, band-terminations), the observation of the oblate-deformed open-quotes dipoleclose quotes bands, studies of reflection-asymmetric shapes, studies of (quasimolecular) cluster configurations in light nuclei, and many, many others. The author reviews the forefront research at Daresbury from the global perspective; the common denominator being the nuclear shape deformation

  13. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1994-01-01

    Research is being conducted by Oak Ridge National Laboratory under U.S. Nuclear Regulatory Commission sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the US-NRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of nondestructive evaluation techniques, assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants. (author). 29 refs., 2 figs

  14. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.; Graves, H.L. III; Norris, W.E.

    1996-01-01

    Research is being conducted by Oak Ridge National Laboratory under US nuclear regulatory commission (USNRC) sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a structural materials information center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of non-destructive evaluation techniques, assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants. (orig.)

  15. Reactors licensing: proposal of an integrated quality and environment regulatory structure for nuclear research reactors in Brazil

    International Nuclear Information System (INIS)

    Serra, Reynaldo Cavalcanti

    2014-01-01

    A new integrated regulatory structure based on quality and integrated issues has been proposed to be implemented on the licensing process of nuclear research reactors in Brazil. The study starts with a literature review about the licensing process in several countries, all of them members of the International Atomic Energy Agency. After this phase it is performed a comparative study with the Brazilian licensing process to identify good practices (positive aspects), the gaps on it and to propose an approach of an integrated quality and environmental management system, in order to contribute with a new licensing process scheme in Brazil. The literature review considered the following research nuclear reactors: Jules-Horowitz and OSIRIS (France), Hanaro (Korea), Maples 1 and 2 (Canada), OPAL (Australia), Pallas (Holand), ETRR-2 (Egypt) and IEA-R1 (Brazil). The current nuclear research reactors licensing process in Brazil is conducted by two regulatory bodies: the Brazilian National Nuclear Energy Commission (CNEN) and the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). CNEN is responsible by nuclear issues, while IBAMA by environmental one. To support the study it was applied a questionnaire and interviews based on the current regulatory structure to four nuclear research reactors in Brazil. Nowadays, the nuclear research reactor’s licensing process, in Brazil, has six phases and the environmental licensing process has three phases. A correlation study among these phases leads to a proposal of a new quality and environmental integrated licensing structure with four harmonized phases, hence reducing potential delays in this process. (author)

  16. Nuclear structure of {sup 231}Ac

    Energy Technology Data Exchange (ETDEWEB)

    Boutami, R. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Borge, M.J.G. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain)], E-mail: borge@iem.cfmac.csic.es; Mach, H. [Department of Radiation Sciences, ISV, Uppsala University, SE-751 21 Uppsala (Sweden); Kurcewicz, W. [Department of Physics, University of Warsaw, Pl-00 681 Warsaw (Poland); Fraile, L.M. [Departamento Fisica Atomica, Molecular y Nuclear, Facultad CC. Fisicas, Universidad Complutense, E-28040 Madrid (Spain); ISOLDE, PH Department, CERN, CH-1211 Geneva 23 (Switzerland); Gulda, K. [Department of Physics, University of Warsaw, Pl-00 681 Warsaw (Poland); Aas, A.J. [Department of Chemistry, University of Oslo, PO Box 1033, Blindern, N-0315 Oslo (Norway); Garcia-Raffi, L.M. [Instituto de Fisica Corpuscular, CSIC - Universidad de Valencia, Apdo. 22805, E-46071 Valencia (Spain); Lovhoiden, G. [Department of Physics, University of Oslo, PO Box 1048, Blindern, N-0316 Oslo (Norway); Martinez, T.; Rubio, B.; Tain, J.L. [Instituto de Fisica Corpuscular, CSIC - Universidad de Valencia, Apdo. 22805, E-46071 Valencia (Spain); Tengblad, O. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); ISOLDE, PH Department, CERN, CH-1211 Geneva 23 (Switzerland)

    2008-10-15

    The low-energy structure of {sup 231}Ac has been investigated by means of {gamma} ray spectroscopy following the {beta}{sup -} decay of {sup 231}Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of {sup 231}Ra {yields}{sup 231}Ac has been constructed for the first time. The Advanced Time Delayed {beta}{gamma}{gamma}(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

  17. Oversized 250 GHz Traveling Wave Tube with a Photonic Band-Gap Structure

    Science.gov (United States)

    Rosenzweig, Guy; Shapiro, Michael A.; Temkin, Richard J.

    2017-10-01

    The challenge in manufacturing traveling wave tubes (TWTs) at high frequencies is that the sizes of the structures scale with, and are much smaller than, the wavelength. We have designed and are building a 250 GHz TWT that uses an oversized structure to overcome fabrication and power handling issues that result from the small dimensions. Using a photonic band-gap (PBG) structure, we succeeded to design the TWT with a beam tunnel diameter of 0.72 mm. The circuit consists of metal plates with the beam tunnel drilled down their center. Twelve posts are protruding on one side of each plate in a triangular array and corresponding sockets are drilled on the other side. The posts of each plate are inserted into the sockets of an adjacent plate, forming a PBG lattice. The vacuum spacing between adjacent plates forms the `PBG cavity''. The full structure is a series of PBG coupled cavities, with microwave power coupling through the beam tunnel. The PBG lattice provides confinement of microwave power in each of the cavities and can be tuned to give the right amount of diffraction per cavity so that no sever is needed to suppress oscillations in the operating mode. CST PIC simulations predict over 38 dB gain with 67 W peak power, using a 30 kV, 310 mA electron beam, 0.6 mm in diameter. Research supported by the AFOSR Program on Plasma and Electro-Energetic Physics and by the NIH National Institute of Biomedical Imaging and Bioengineering.

  18. Photonic band gap structure for a ferroelectric photonic crystal at microwave frequencies.

    Science.gov (United States)

    King, Tzu-Chyang; Chen, De-Xin; Lin, Wei-Cheng; Wu, Chien-Jang

    2015-10-10

    In this work, the photonic band gap (PBG) structure in a one-dimensional ferroelectric photonic crystal (PC) is theoretically investigated. We consider a PC, air/(AB)N/air, in which layer A is a dielectric of MgO and layer B is taken to be a ferroelectric of Ba0.55Sr0.45TiO3 (BSTO). With an extremely high value in the dielectric constant in BSTO, the calculated photonic band structure at microwave frequencies exhibits some interesting features that are significantly different from those in a usual dielectric-dielectric PC. First, the photonic transmission band consists of multiple and nearly discrete transmission peaks. Second, the calculated bandwidth of the PBG is nearly unchanged as the angle of incidence varies in the TE wave. The bandwidth will slightly reduce for the TM mode. Thus, a wide omnidirectional PBG can be obtained. Additionally, the effect of the thickness of the ferroelectric layer on the PBG is much more pronounced compared to the dielectric layer thickness. That is, the increase of ferroelectric thickness can significantly decrease the PBG bandwidth.

  19. One-dimensional electromagnetic band gap plasma structure formed by atmospheric pressure plasma inhomogeneities

    Science.gov (United States)

    Babitski, V. S.; Callegari, Th.; Simonchik, L. V.; Sokoloff, J.; Usachonak, M. S.

    2017-08-01

    The ability to use plasma columns of pulse discharges in argon at atmospheric pressure to form a one-dimensional electromagnetic band gap structure (or electromagnetic crystal) in the X-band waveguide is demonstrated. We show that a plasma electromagnetic crystal attenuates a microwave propagation in the stopband more than by 4 orders of magnitude. In order to obtain an effective control of the transmission spectrum comparable with a metallic regular structure, the electron concentration in plasma inhomogeneities should vary within the range from 1014 cm-3 to 1016 cm-3, while gas temperature and mean electron energy must be in the range of 2000 K and 0.5 eV, respectively, to lower electron collision frequency around 1010 s-1. We analyze in detail the time evolution response of the electromagnetic crystal according to the plasma parameters for the duration of the discharge. The interest of using atmospheric pressure discharges is to increase the microwave breakdown threshold in discharge volumes, whereby it becomes possible to perform dynamic control of high power microwaves.

  20. Nuclear structure of the transactinides – investigated by decay spectroscopy

    Directory of Open Access Journals (Sweden)

    Heßberger Fritz Peter

    2016-01-01

    Full Text Available Superheavy elements owe their stability due to a subtle balance between the disruptive Coulomb force and the attractive nuclear forces. Thus they represent an ideal laboratory to study basic interactions. The essential tools are detailed investigations of radioactive decay properties and nuclear structure of superheavy nuclei. The results of those studies will deliver valuable input to improve theoretical models. To fulfill this demand conclusive data of high quality are necessary, which is presently not so easy to meet due to small production cross sections and technical limitations (beam intensities, detection probabilities. Possibilities and problems concerning extraction of decay properties and nuclear structure information on the basis of a low number of observed decay events will be discussed for three illustrative examples, 257Rf, 257Lr, and 288Fl.

  1. Structure and gating of the nuclear pore complex

    Science.gov (United States)

    Eibauer, Matthias; Pellanda, Mauro; Turgay, Yagmur; Dubrovsky, Anna; Wild, Annik; Medalia, Ohad

    2015-06-01

    Nuclear pore complexes (NPCs) perforate the nuclear envelope and allow the exchange of macromolecules between the nucleus and the cytoplasm. To acquire a deeper understanding of this transport mechanism, we analyse the structure of the NPC scaffold and permeability barrier, by reconstructing the Xenopus laevis oocyte NPC from native nuclear envelopes up to 20 Å resolution by cryo-electron tomography in conjunction with subtomogram averaging. In addition to resolving individual protein domains of the NPC constituents, we propose a model for the architecture of the molecular gate at its central channel. Furthermore, we compare and contrast this native NPC structure to one that exhibits reduced transport activity and unveil the spatial properties of the NPC gate.

  2. A gene delivery system containing nuclear localization signal: Increased nucleus import and transfection efficiency with the assistance of RanGAP1.

    Science.gov (United States)

    Chen, Kang; Guo, Lingling; Zhang, Jiulong; Chen, Qing; Wang, Kuanglei; Li, Chenxi; Li, Weinan; Qiao, Mingxi; Zhao, Xiuli; Hu, Haiyang; Chen, Dawei

    2017-01-15

    In the present report, a degradable gene delivery system (PAMS/DNA/10NLS) containing nucleus location signal peptide (NLS) was prepared. The agarose gel electrophoresis, particle size and zeta potential of PAMS/DNA/10NLS were similar to those of PAMS/DNA, which proved that NLS did not affect the interaction between PAMS and DNA. PAMS/DNA/10NLS exhibited marked extracellular and intracellular degradation under acidic conditions. The degradation was believed to allow NLS to come into contact with importins easily, which was able to mediate the nucleus import. With the help of NLS, PAMS/DNA/10NLS exhibited a higher transfection capability than PAMS/DNA. Moreover, the transfection of PAMS/DNA/10NLS was less dependent on the breakdown of the nucleus envelope than PAMS/DNA. Considering that GTPase-activating protein 1 (RanGAP1) was able to activate the endogenous GTPase, which was necessary for NLS-mediated nucleus import, RanGAP1 overexpressed cells (RanGAP1 cells) were produced. This result showed that RanGAP1 cells had higher GTPase activities than normal cells. Both the nucleus import and transfection efficiency of PAMS/DNA/10NLS were markedly higher in RanGAP1 cells than that in normal cells. The in vivo transfection results also showed that the transfection efficiency of PAMS/DNA/10NLS was higher in RanGAP1 pre-treated mice than that in normal mice. These findings showed that PAMS/DNA/10NLS is a promising gene delivery system with the assistance of RanGAP1. The present report describes the increased transfection efficiency of a degradable gene delivery system (PAMS/DNA/10NLS) containing nuclear location signal (NLS) with the assistance of GTPase-activating protein 1 (RanGAP1). The physicochemical properties of PAMS/DNA/10NLS were similar to those of PAMS/DNA. PAMS/DNA/10NLS exhibited great extracellular and intracellular degradations, which might allow NLS to contact with importins easily. With the help of NLS, PAMS/DNA/10NLS exhibited a higher transfection

  3. Quality assurance in the structural installations of nuclear power stations

    International Nuclear Information System (INIS)

    Schnellenbach, G.; Wrage, S.

    1985-01-01

    The concept of quality assurance distinguishes between self-monitoring of the design, manufacturing and executing firms and external monitoring by state institutions or by experts commissioned by them. The long-term control of structures is within the area of responsibility of the owner. This quality assurance concept is controlled in detail by statutes, which clearly define responsibilities. This structural engineering quality assurance system also forms the basis for the design, construction and utilization of structural installations of nuclear power stations; requirements emanating from the Atomic Energy Acts for the structural installations demand, however, to some extent a sharpening of self- and external monitoring. Therefore, today a quality concept has been developed for the important engineering safety-related buildings of nuclear power stations. This concept takes account of the strict requirements imposed and fulfils the requirement of KTA 1401. (orig.) [de

  4. Exotic nuclei: another aspect of nuclear structure

    International Nuclear Information System (INIS)

    Dobaczewski, J.; Blumenfeld, Y.; Flocard, H.; Garcia Borge, M.J.; Nowacki, F.; Rombouts, S.; Theisen, Ch.; Marques, F.M.; Lacroix, D.; Dessagne, P.; Gaeggeler, H.

    2002-01-01

    This document gathers the lectures made at the Joliot Curie international summer school in 2002 whose theme that year was exotic nuclei. There were 11 contributions whose titles are: 1) interactions, symmetry breaking and effective fields from quarks to nuclei; 2) status and perspectives for the study of exotic nuclei: experimental aspects; 3) the pairing interaction and the N = Z nuclei; 4) borders of stability region and exotic decays; 5) shell structure of nuclei: from stability to decay; 6) variational approach of system with a few nucleons; 7) from heavy to super-heavy nuclei; 8) halos, molecules and multi-neutrons; 9) macroscopic approaches for fusion reactions; 10) beta decay: a tool for spectroscopy; 11) the gas phase chemistry of super-heavy elements

  5. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1992-01-01

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A ≅ 182 region, structure of 182 Hg and 182 Au at high spin, a highly deformed band in 136 Pm and the anomalous h 11/2 proton crossing in the A∼135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier α particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative 209 Bi + 136 Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4π channel selection device, a novel x-ray detector, and a simple channel-selecting detector)

  6. Microscopic description of nuclear structure; La structure nucleaire decrite par les theories microscopiques

    Energy Technology Data Exchange (ETDEWEB)

    Girod, M.; Berger, J.F.; Peru, S.; Dancer, H. [CEA Bruyeres-le-Chatel, 91 (France)

    2002-07-01

    After briefly recalling the formalism of the mean field approach with an effective nucleon-nucleon interaction, the theoretical framework of the nuclear structure studies performed at CEA-DAM, applications of this theory to various nuclear systems: shape and spin isomeric states, neutron and proton rich nuclei, superheavy and hyper-heavy nuclei, and to the fission process are presented. (authors)

  7. Nuclear structure at high spin using multidetector gamma array and ...

    Indian Academy of Sciences (India)

    2014-04-05

    Apr 5, 2014 ... A multidetector gamma array (GDA), for studying nuclear structure was built with ancillary devices namely gamma multiplicity filter and charged particle detector array. This facility was designed for in-beam gamma spectroscopy measurements in fusion evaporation reactions at Inter-University Accelerator ...

  8. Optical spectroscopy by Hantaro Nagaoka Pioneer nuclear structure study

    Science.gov (United States)

    Inamura, Takashi T.

    2000-08-01

    Hantaro Nagaoka is a Japanese physicist who made an experimental pioneer work on optical spectroscopy for nuclear structure studies in 1920s. Today much attention should be paid to this work rather than to his famous atomic model that died away long time ago along with Thomson's model.

  9. Optical spectroscopy by Hantaro Nagaoka - Pioneer nuclear structure study

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Takashi T. [Warsaw University, Heavy Ion Laboratory (Poland)], E-mail: inamura@slcj.uw.edu.pl

    2000-08-15

    Hantaro Nagaoka is a Japanese physicist who made an experimental pioneer work on optical spectroscopy for nuclear structure studies in 1920s. Today much attention should be paid to this work rather than to his famous atomic model that died away long time ago along with Thomson's model.

  10. Detailed requirements for a next generation nuclear data structure.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-07-05

    This document attempts to compile the requirements for the top-levels of a hierarchical arrangement of nuclear data such as found in the ENDF format. This set of requirements will be used to guide the development of a new data structure to replace the legacy ENDF format.

  11. Structure of nuclear transition matrix elements for neutrinoless ...

    Indian Academy of Sciences (India)

    Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

  12. Structure of nuclear transition matrix elements for neutrinoless ...

    Indian Academy of Sciences (India)

    Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double-β decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

  13. Structural Health Monitoring of Nuclear Spent Fuel Storage Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Lingyu

    2018-04-10

    Interim storage of spent nuclear fuel from reactor sites has gained additional importance and urgency for resolving waste-management-related technical issues. To ensure that nuclear power remains clean energy, monitoring has been identified by DOE as a high priority cross-cutting need, necessary to determine and predict the degradation state of the systems, structures, and components (SSCs) important to safety (ITS). Therefore, nondestructive structural condition monitoring becomes a need to be installed on existing or to be integrated into future storage system to quantify the state of health or to guarantee the safe operation of nuclear power plants (NPPs) during their extended life span. In this project, the lead university and the collaborating national laboratory teamed to develop a nuclear structural health monitoring (n-SHM) system based on in-situ piezoelectric sensing technologies that can monitor structural degradation and aging for nuclear spent fuel DCSS and similar structures. We also aimed to identify and quantify possible influences of nuclear spent fuel environment (temperature and radiation) to the piezoelectric sensor system and come up with adequate solutions and guidelines therefore. We have therefore developed analytical model for piezoelectric based n-SHM methods, with considerations of temperature and irradiation influence on the model of sensing and algorithms in acoustic emission (AE), guided ultrasonic waves (GUW), and electromechanical impedance spectroscopy (EMIS). On the other side, experimentally the temperature and irradiation influence on the piezoelectric sensors and sensing capabilities were investigated. Both short-term and long-term irradiation investigation with our collaborating national laboratory were performed. Moreover, we developed multi-modal sensing, validated in laboratory setup, and conducted the testing on the We performed multi-modal sensing development, verification and validation tests on very complex structures

  14. Aging of concrete containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.; Mori, Yasuhiro; Arndt, E.G.

    1992-01-01

    Concrete structures play a vital role in the safe operation of all light-water reactor plants in the US Pertinent concrete structures are described in terms of their importance design, considerations, and materials of construction. Degradation factors which can potentially impact the ability of these structures to meet their functional and performance requirements are identified. Current inservice inspection requirements for concrete containments are summarized. A review of the performance history of the concrete components in nuclear power plants is provided. A summary is presented. A summary is presented of the Structural Aging (SAG) Program being conducted at the Oak Ridge National Laboratory for the US Nuclear Regulatory Commission. The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved bases for their continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technologies, and quantitiative methodology for continued service conditions. Objectives and a summary of accomplishments under each of these tasks are presented

  15. In situ structural analysis of the human nuclear pore complex.

    Science.gov (United States)

    von Appen, Alexander; Kosinski, Jan; Sparks, Lenore; Ori, Alessandro; DiGuilio, Amanda L; Vollmer, Benjamin; Mackmull, Marie-Therese; Banterle, Niccolo; Parca, Luca; Kastritis, Panagiotis; Buczak, Katarzyna; Mosalaganti, Shyamal; Hagen, Wim; Andres-Pons, Amparo; Lemke, Edward A; Bork, Peer; Antonin, Wolfram; Glavy, Joseph S; Bui, Khanh Huy; Beck, Martin

    2015-10-01

    Nuclear pore complexes are fundamental components of all eukaryotic cells that mediate nucleocytoplasmic exchange. Determining their 110-megadalton structure imposes a formidable challenge and requires in situ structural biology approaches. Of approximately 30 nucleoporins (Nups), 15 are structured and form the Y and inner-ring complexes. These two major scaffolding modules assemble in multiple copies into an eight-fold rotationally symmetric structure that fuses the inner and outer nuclear membranes to form a central channel of ~60 nm in diameter. The scaffold is decorated with transport-channel Nups that often contain phenylalanine-repeat sequences and mediate the interaction with cargo complexes. Although the architectural arrangement of parts of the Y complex has been elucidated, it is unclear how exactly it oligomerizes in situ. Here we combine cryo-electron tomography with mass spectrometry, biochemical analysis, perturbation experiments and structural modelling to generate, to our knowledge, the most comprehensive architectural model of the human nuclear pore complex to date. Our data suggest previously unknown protein interfaces across Y complexes and to inner-ring complex members. We show that the transport-channel Nup358 (also known as Ranbp2) has a previously unanticipated role in Y-complex oligomerization. Our findings blur the established boundaries between scaffold and transport-channel Nups. We conclude that, similar to coated vesicles, several copies of the same structural building block--although compositionally identical--engage in different local sets of interactions and conformations.

  16. Superconducting gap structure of heavy-Fermion compound URu2Si2 determined by angle-resolved thermal conductivity

    Science.gov (United States)

    Kasahara, Y.; Shishido, H.; Shibauchi, T.; Haga, Y.; Matsuda, T. D.; Onuki, Y.; Matsuda, Y.

    2009-05-01

    In heavy-Fermion compound URu2Si2, unusual superconductivity is embedded in an enigmatic 'hidden order' phase. Recently, it has been shown that URu2Si2 is essentially a multiband superconductor associated with the semimetallic compensated electronic structure. Here, to pin down the detailed superconducting gap structure, we have performed thermal transport measurements on ultraclean URu2Si2 single crystals in magnetic fields rotating various directions relative to the crystal axes. By changing the amplitude of magnetic fields, we determined the nodal topology of electron and hole band separately. The results indicate a new type of unconventional superconductivity with two distinct gaps, in which horizontal line nodes lie within the basal ab plane of the light-hole band with small gap and point nodes along the c-axis in the heavy electron band with large gap. This gap structure is consistent with 'chiral' d-wave symmetry with a form {\\hat{k}}_{z}({\\hat{k}}_{x}+i{\\hat{k}}_{y}) .

  17. Superconducting gap structure of heavy-Fermion compound URu2Si2 determined by angle-resolved thermal conductivity

    International Nuclear Information System (INIS)

    Kasahara, Y; Shishido, H; Shibauchi, T; Matsuda, Y; Haga, Y; Matsuda, T D; Onuki, Y

    2009-01-01

    In heavy-Fermion compound URu 2 Si 2 , unusual superconductivity is embedded in an enigmatic 'hidden order' phase. Recently, it has been shown that URu 2 Si 2 is essentially a multiband superconductor associated with the semimetallic compensated electronic structure. Here, to pin down the detailed superconducting gap structure, we have performed thermal transport measurements on ultraclean URu 2 Si 2 single crystals in magnetic fields rotating various directions relative to the crystal axes. By changing the amplitude of magnetic fields, we determined the nodal topology of electron and hole band separately. The results indicate a new type of unconventional superconductivity with two distinct gaps, in which horizontal line nodes lie within the basal ab plane of the light-hole band with small gap and point nodes along the c-axis in the heavy electron band with large gap. This gap structure is consistent with 'chiral' d-wave symmetry with a form k-circumflex z (k-circumflex x +ik-circumflex y ).

  18. Structural design of nuclear power plant using stiffened steel plate concrete structure

    International Nuclear Information System (INIS)

    Moon, Ilhwan; Kim, Sungmin; Mun, Taeyoup; Kim, Keunkyeong; Sun, Wonsang

    2009-01-01

    Nuclear power is an alternative energy source that is conducive to mitigate the environmental strains. The countries having nuclear power plants are encouraging research and development sector to find ways to construct safer and more economically feasible nuclear power plants. Modularization using Steel Plate Concrete(SC) structure has been proposed as a solution to these efforts. A study of structural modules using SC structure has been performed for shortening of construction period and enhancement of structural safety of NPP structures in Korea. As a result of the research, the design code and design techniques based on limit state design method has been developed. The design code has been developed through various structural tests and theoretical studies, and it has been modified by application design of SC structure for NPP buildings. The code consists of unstiffened SC wall design, stiffened SC wall design, Half-SC slab design, stud design, connection design and so on. The stiffened steel plate concrete(SSC) wall is SC structure whose steel plates with ribs are composed on both sides of the concrete wall, and this structure was developed for improved constructability and safety of SC structure. This paper explains a design application of SC structure for a sample building specially devised to reflect all of major structural properties of main buildings of APR1400. In addition, Stiffening effect of SSC structure is evaluated and structural efficiency of SSC structure is verified in comparison with that of unstiffened SC structure. (author)

  19. Nuclear magnetic and quadrupole moments for nuclear structure research on exotic nuclei

    CERN Document Server

    Neyens, G

    2003-01-01

    One of the key issues in current nuclear physics research is to investigate the properties of so-called 'exotic nuclei' and of 'exotic nuclear structures'. Exotic nuclei are nuclei with a proton-to-neutron ratio that is very different from the proton-to-neutron ratio in stable nuclei (a technical term related to this ratio is the 'isospin'). We define exotic nuclear structures as excitation modes of nuclei that have a very different structure than the structure (or shape) of the nuclear ground state. By putting the nucleons in a nucleus to extreme conditions of isospin and excitation energy one can investigate details of one of the four basic forces in nature: the strong force which binds the nucleons together to form a bound nucleus. While the basic properties of the strong nucleon-nucleon interaction are known from investigating the properties of nuclei near the 'valley of stability', recent developments in the study of exotic nuclei have demonstrated that specific properties of the strong interaction, such...

  20. The Gender Gap in Student Engagement: The Role of Teachers' Autonomy Support, Structure, and Involvement

    Science.gov (United States)

    Lietaert, Sofie; Roorda, Debora; Laevers, Ferre; Verschueren, Karine; De Fraine, Bieke

    2015-01-01

    Background: The gender gap in education in favour of girls is a widely known phenomenon. Boys generally have higher dropout rates, obtain lower grades, and show lower engagement. Insight into factors related to these academic outcomes could help to address the gender gap. Aims: This study investigated, for Dutch language classes, (1) how boys and…

  1. NUCLEAR STRUCTURE AND DECAY DATA: INTRODUCTION TO RELEVANT WEB PAGES

    International Nuclear Information System (INIS)

    BURROWS, T.W.; MCLAUGHLIN, P.D.; NICHOLS, A.L.

    2005-01-01

    A brief description is given of the nuclear data centres around the world able to provide access to those databases and programs of highest relevance to nuclear structure and decay data specialists. A number of Web-page addresses are also provided for the reader to inspect and investigate these data and codes for study, evaluation and calculation. These instructions are not meant to be comprehensive, but should provide the reader with a reasonable means of electronic access to the most important data sets and programs

  2. Considerations about soil-structures interaction in nuclear power plants

    International Nuclear Information System (INIS)

    Muzzi, F.

    1977-01-01

    The main features of the soil-structure interaction for nuclear power plant are presented as they resulted from conservations that the author carried out at the Berkeley (California) University, at the California Institute of Technology and at the U.S. Nuclear Regulatory Commission in Washington (Dec 1975). The complete and inertial interaction approaches of analysis are discussed. The complete approach by the use of finite element technique as suggested by the U.S.N.R.C. Standard Review Plan 3.7.1. (June 1975) is finally described. (author)

  3. Muonic radioactive atoms a unique probe for nuclear structure

    CERN Document Server

    Nilsson, Thomas; Kolbe, E; Langanke, K; Martínez-Pinedo, G; Riisager, Karsten

    2004-01-01

    Muonic atoms have been a source of high-precision experimental nuclear structure data for decades, through muonic X-rays that yield information on nuclear charge distributions. The intense driver beams for production of radioactive beams in so-called second generation facilities will simultaneously be capable of producing unprecedented amounts of low-energy muons. This paper concerns some of the potential synergies of combining muons with radioactive nuclei as one possible new tool to be used at future RIB facilities. As a case study, muonic capture rates into highly excited states in /sup 78/Ni have been calculated.

  4. Development of SC structure modularization in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Mun, Taeyoup

    2008-01-01

    New Focus on NPP are Rising Concerns on Global Warming, Potential energy crisis (geo-political), Improved reliability and safety of nuclear power plant, Advent of Generation 3+ NPP technology and Economical Energy Resource. New NPPs are 6 units in Korea and 23 in Asia being built, 32 units being planned in China by 2020 (150 by 2050), 10 units being planned in US by 2020 and IAEA expects $200 billions on NPP construction next 25 years (up to 30% of total world energy). □ SC(Steel Plate Concrete) structure · Steel Plate is used as a Structural Element instead of Reinforcing Bars in RC · SC structure consists of Steel Plate with Headed Studs. Connected by Tie-bars - The Primary Purpose of Tie-bars is to Stiffen and Hold Together the Plates during Construction Process - Headed Studs are Welded to the Inside of Steel Plate for composite action □ Benefits of SC Structure · Shorten Construction Duration for Re bar, Forming and Scaffolding Works · Minimize Site Labors · Improve the Construction Quality · Enable Construction Sites to be kept Clean □ SC Modularization · Fit for Modular Construction for Structural Features · Fit for Modular Construction for Structural Features · Inattentively Effective for Integrated Modules · Pre-fabrication, Pre-assembly and Modularization □ Project Overview · Project Name: Development of SC structure for Modularization in NPP · Project Type: Electric Power Industry R and D (Ministry of Knowledge Economy) · Duration: Sep. 2005 ∼ Aug. 2008 (36 Months) · Research Team and Scopes - Project Management: Korea Hydro and Nuclear Power Company (KHNP) - Development of Code and Standards for SC Structure: Korea Society of Steel Construction (KSSC) Korea Electric Power Research Institute (KEPRI) - Development of SC Structural Analysis and Design: Korea Power Engineering Company (KOPEC) - Development of Construction Techniques for SC Modularization: KHNP, Korea Institute of Nuclear Safety(KINS), KOPEC □ Performance

  5. A new magnetorheological mount featured by changeable damping gaps using a moved-plate valve structure

    International Nuclear Information System (INIS)

    Phu, Do Xuan; Shah, Kruti; Choi, Seung-Bok

    2014-01-01

    In this work, a new type of a magnetorheological (MR) fluid mount is proposed and its performances are experimentally investigated. The design of this MR mount is based on two operating modes of MR fluid: flow mode and shear mode. These modes are applied to the mechanism design consisting of two components: a fixed plate for applying the flow mode, and a moved plate for applying the shear mode of MR fluid motion. These plates belong to the valve-type structure of MR mount. The primary objective using the moved plate is to overcome the block-up phenomenon which frequently occurs in the conventional-type MR mount, in which there is no flow of MR fluid through the damping gap. In this research, a laboratorial fluid (MRF140) is used in the design and optimization of MR mount. This fluid features plate-like particles unlike the sphere particles. The yield stress of the fluid is measured as a function of the magnetic field and the theoretical analysis for the mount design is undertaken using the properties of the MR fluid, followed by design optimization. The objective function is concentrated on maximal damping force of the MR mount subjected to parameter constraints. Based on the results of optimization, the proposed MR mount is manufactured and tested for the performance evaluation. Vibration control capability and block-up phenomenon are investigated and compared between the proposed and conventional MR mounts. (paper)

  6. Book of abstracts of 13. national conference on nuclear structure and 9. symposium on 'nuclear structure and quantum mechanics'

    International Nuclear Information System (INIS)

    2010-07-01

    13. national conference on nuclear structure and 9. symposium on 'nuclear structure and quantum mechanics' was held by China Nuclear Physics Society in Chifeng, 25 to 30 July, 2010. The proceedings collects the abstracts of 102 articles

  7. Computing the band structure and energy gap of penta-graphene by using DFT and G0W0 approximations

    OpenAIRE

    Einollahzadeh, H.; Dariani, R. S.; Fazeli, S. M.

    2015-01-01

    In this paper, we consider the optimum coordinate of the penta-graphene. Penta-graphene is a new stable carbon allotrope which is stronger than graphene. Here, we compare the band gap of penta-graphene with various density functional theory (DFT) methods. We plot the band structure of penta-graphene which calculated with the generalized gradient approximation functional, about Fermi energy.

  8. Crystal Structure of the Herpesvirus Nuclear Egress Complex Provides Insights into Inner Nuclear Membrane Remodeling

    Directory of Open Access Journals (Sweden)

    Tzviya Zeev-Ben-Mordehai

    2015-12-01

    Full Text Available Although nucleo-cytoplasmic transport is typically mediated through nuclear pore complexes, herpesvirus capsids exit the nucleus via a unique vesicular pathway. Together, the conserved herpesvirus proteins pUL31 and pUL34 form the heterodimeric nuclear egress complex (NEC, which, in turn, mediates the formation of tight-fitting membrane vesicles around capsids at the inner nuclear membrane. Here, we present the crystal structure of the pseudorabies virus NEC. The structure revealed that a zinc finger motif in pUL31 and an extensive interaction network between the two proteins stabilize the complex. Comprehensive mutational analyses, characterized both in situ and in vitro, indicated that the interaction network is not redundant but rather complementary. Fitting of the NEC crystal structure into the recently determined cryoEM-derived hexagonal lattice, formed in situ by pUL31 and pUL34, provided details on the molecular basis of NEC coat formation and inner nuclear membrane remodeling.

  9. Nuclear structure investigations with inclusion of continuum states

    International Nuclear Information System (INIS)

    Rotter, I.

    1983-09-01

    The influence of the continuum on the properties of discrete nuclear states is reviewed. It is described on the basis of a continuum shell model. The coupling of the discrete states to the continuum results in an additional term to the Hamiltonian, commonly used in the study of nuclear structure, and an additional term to the wavefunction of the discrete state. These additional terms characterise finite nuclei in contrast to nuclear matter. They result in some symmetry violation of the residual nuclear interaction such as charge symmetry violation, and describe the nuclear surface, respectively. The energies and widths of resonance states result from the complex eigenvalues of the Hamiltonian. The partial widths are shown to be factorisable into a spectroscopic factor and into a penetration factor if the spectroscopic factor is large. An expression for the S-matrix is derived in which instead of the so-called resonance parameters, functions appear which are calculated in the framework of the model. The line shape of resonances is also influenced by these functions. As an extreme case, a resonance may have the appearance of a cusp. The conclusions drawn are supported by the results of numerical calculations performed in the continuum shell model for light nuclei with realistic shell model wavefunctions. (author)

  10. Full scale dynamic testing of Paks nuclear power plant structures

    International Nuclear Information System (INIS)

    Da Rin, E.M.

    1995-01-01

    This report refers to the full-scale dynamic structural testing activities that have been performed in December 1994 at the Paks (H) Nuclear Power Plant, within the framework of: the IAEA Coordinated research Programme 'Benchmark Study for the Seismic Analysis and Testing of WWER-type Nuclear Power Plants, and the nuclear research activities of ENEL-WR/YDN, the Italian National Electricity Board in Rome. The specific objective of the conducted investigation was to obtain valid data on the dynamic behaviour of the plant's major constructions, under normal operating conditions, for enabling an assessment of their actual seismic safety to be made. As described in more detail hereafter, the Paks NPP site has been subjected to low level earthquake like ground shaking, through appropriately devised underground explosions, and the dynamic response of the plant's 1 st reactor unit important structures was appropriately measured and digitally recorded. In-situ free field response was measured concurrently and, moreover, site-specific geophysical and seismological data were simultaneously acquired too. The above-said experimental data is to provide basic information on the geophysical and seismological characteristics of the Paks NPP site, together with useful reference information on the true dynamic characteristics of its main structures and give some indications on the actual dynamic soil-structure interaction effects for the case of low level excitation

  11. Nuclear structure in cold rearrangement processes in fission and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, P.

    1998-11-01

    In fission and fusion of heavy nuclei large numbers of nucleons are rearranged at a scale of excitation energy very small compared to the binding energy of the nuclei. The energies involved are less than 40 MeV at nuclear temperatures below 1.5 MeV. The shapes of the configurations in the rearrangement of a binary system into a monosystem in fusion, or vice versa in fission, change their elongations by as much as 8 fm, the radius of the monosystem. The dynamics of the reactions macroscopically described by a potential energy surface, inertia parameters, dissipation, and a collision energy is strongly modified by the nuclear structure of the participating nuclei. Experiments showing nuclear structure effects in fusion and fission of the heaviest nuclei are reviewed. The reaction kinematics and the multitude of isotopes involved are investigated by detector techniques and by recoil spectrometers. The advancement of the latter allows to find very small reaction branches in the range of 10{sup -5} to 10{sup -10}. The experiments reveal nuclear structure effects in all stages of the rearrangement processes. These are discussed pointing to analogies in fusion and fission on the microscopic scale, notwithstanding that both processes macroscopically are irreversible. Heavy clusters, as 132Sn, 208Pb, nuclei with closed shell configurations N=82,126, Z=50,82 survive in large parts of the nuclear rearrangement. They determine the asymmetry in the mass distribution of low energy fission, and they allow to synthesise superheavy elements, until now up to element 112. Experiments on the cold rearrangement in fission and fusion are presented. Here, in the range of excitation energies below 12 MeV the phenomena are observed most convincingly. (orig.)

  12. Equation of state of dense nuclear matter and neutron star structure from nuclear chiral interactions

    Science.gov (United States)

    Bombaci, Ignazio; Logoteta, Domenico

    2018-02-01

    Aims: We report a new microscopic equation of state (EOS) of dense symmetric nuclear matter, pure neutron matter, and asymmetric and β-stable nuclear matter at zero temperature using recent realistic two-body and three-body nuclear interactions derived in the framework of chiral perturbation theory (ChPT) and including the Δ(1232) isobar intermediate state. This EOS is provided in tabular form and in parametrized form ready for use in numerical general relativity simulations of binary neutron star merging. Here we use our new EOS for β-stable nuclear matter to compute various structural properties of non-rotating neutron stars. Methods: The EOS is derived using the Brueckner-Bethe-Goldstone quantum many-body theory in the Brueckner-Hartree-Fock approximation. Neutron star properties are next computed solving numerically the Tolman-Oppenheimer-Volkov structure equations. Results: Our EOS models are able to reproduce the empirical saturation point of symmetric nuclear matter, the symmetry energy Esym, and its slope parameter L at the empirical saturation density n0. In addition, our EOS models are compatible with experimental data from collisions between heavy nuclei at energies ranging from a few tens of MeV up to several hundreds of MeV per nucleon. These experiments provide a selective test for constraining the nuclear EOS up to 4n0. Our EOS models are consistent with present measured neutron star masses and particularly with the mass M = 2.01 ± 0.04 M⊙ of the neutron stars in PSR J0348+0432.

  13. Nuclear structure and decay data evaluation in Europe

    Science.gov (United States)

    Negret, Alexandru; Balabanski, Dimiter; Dimitriou, Paraskevi; Elekes, Zoltan; Mertzimekis, Theo J.; Pascu, Sorin; Timar, Janos

    2017-09-01

    Nuclear Structure and Decay Data (NSDD) activities in Europe include mass-chain and individual nuclei evaluations as well as horizontal evaluations and compilations, data dissemination and educational activities. As such they are essential for a large range of applications from energy, environmental, and medical to basic research in nuclear structure and reactions, all of which are intensively pursued in Europe. Although the NSDD evaluation groups in Europe form part of the international network of NSDD evaluators, which is coordinated by the International Atomic Energy Agency, they are faced with some very distinct challenges. We shortly present the NSDD Data Centre at IFIN-HH, Bucharest and discuss possible actions to improve the situation for the entire European NSDD evaluation effort.

  14. Nuclear structure and decay data evaluation in Europe

    Directory of Open Access Journals (Sweden)

    Negret Alexandru

    2017-01-01

    Full Text Available Nuclear Structure and Decay Data (NSDD activities in Europe include mass-chain and individual nuclei evaluations as well as horizontal evaluations and compilations, data dissemination and educational activities. As such they are essential for a large range of applications from energy, environmental, and medical to basic research in nuclear structure and reactions, all of which are intensively pursued in Europe. Although the NSDD evaluation groups in Europe form part of the international network of NSDD evaluators, which is coordinated by the International Atomic Energy Agency, they are faced with some very distinct challenges. We shortly present the NSDD Data Centre at IFIN-HH, Bucharest and discuss possible actions to improve the situation for the entire European NSDD evaluation effort.

  15. Technical limitations of nuclear fuel materials and structures

    International Nuclear Information System (INIS)

    Hansson, L.; Planman, T.; Vitikainen, E.

    1993-05-01

    This report gives a summary of the tasks carried out within the project 'Technical limitations of nuclear fuel materials and structures' which belongs to the Finnish national research programme called 'Systems behaviour and operational aspects of safety'. The duration of the project was three years from 1990 to 1992. Most western LWR utilities, including the two Finnish ones have an incentive to implement extended burnup fuel cycles in their nuclear power plants. The aim of this project has been authorities to support them in the assessment and licensing of new fuel designs and materials. The research work of the project was focused on collecting and qualifying fuel performance data and on performing laboratory tests on fresh and irradiated cladding and structural materials. Moreover, knowledge of the high burnup phenomena was obtained through participation in international research projects such as OECD Halden Project and several Studsvik projects. Experimental work within the framework of the VVER fuel cooperative effort was also continued. (orig.)

  16. Dismantling of nuclear facilities. From a structural engineering perspective

    International Nuclear Information System (INIS)

    Block, Carsten; Henkel, Fritz-Otto; Bauer, Thomas

    2014-01-01

    The paper summarizes some important aspects, requirements and technical boundary conditions that need to be considered in dismantling projects in the nuclear sector from a structural engineering perspective. Besides general requirements regarding radiation protection, occupational safety, efficiency and cost effectiveness it is important to take into account other conditions which have a direct impact on technical details and the structural assessment of the dismantling project. These are the main aspects highlighted in this paper: - The structural assessment of dismantling projects has to be based on the as-built situation. - The limitations in terms of available equipment and space have to be taken into account. - The structural assessments are often non-standardized engineering evaluations. A selection of five dismantling projects illustrates the various structural aspects. (orig.)

  17. EVALUATED NUCLEAR STRUCTURE DATA FILE. A MANUAL FOR PREPARATION OF DATA SETS

    International Nuclear Information System (INIS)

    TULI, J.K.

    2001-01-01

    This manual describes the organization and structure of the Evaluated Nuclear Structure Data File (ENSDF). This computer-based file is maintained by the National Nuclear Data Center (NNDC) at Brookhaven National Laboratory for the international Nuclear Structure and Decay Data Network. For every mass number (presently, A ≤ 293), the Evaluated Nuclear Structure Data File (ENSDF) contains evaluated structure information. For masses A ≥ 44, this information is published in the Nuclear Data Sheets; for A < 44, ENSDF is based on compilations published in the journal Nuclear Physics. The information in ENSDF is updated by mass chain or by nuclide with a varying cycle time dependent on the availability of new information

  18. ENEA activities on seismic isolation of nuclear and non-nuclear structures

    International Nuclear Information System (INIS)

    Martelli, A.; Masoni, P.; Forni, M.; Indirli, M.; Spadoni, B.; Di Pasquale, G.; Lucarelli, V.; Sano, T.; Bonacina, G.; Castoldi, A.

    1989-01-01

    Work on seismic isolation of nuclear and non-nuclear structures was started by ENEA in cooperation with ISMES in 1988. The first activity consisted of a proposal for guidelines for seismically isolated nuclear plants using high-damping, steel-laminated elastomer bearings. This is being performed in the framework of an agreement with General Electric Company. Furthermore, research and development work has been defined and recently initiated to support development of the seismic isolation guidelines as well as that of qualification procedures for seismic isolation systems in general. The present R and D work includes static and dynamic experiments on single bearings, shake table tests with multi-axial simultaneous excitations on reduced-scale mockups of isolated structures supported by multiple bearings, and dynamic tests on large-scale isolated structures with on-site test techniques. It also includes the development and validation of finite-element nonlinear models of the single bearings, as well as those of simplified design tools for the analysis of the isolated structures dynamic behavior. Extension of this work is foreseen in a wider national frame

  19. Nuclear Structure Aspects of Neutrinoless Double-β Decay

    Science.gov (United States)

    Brown, B. A.; Horoi, M.; Sen'kov, R. A.

    2014-12-01

    We decompose the neutrinoless double-β decay matrix elements into sums of products over the intermediate nucleus with two less nucleons. We find that the sum is dominated by the Jπ=0+ ground state of this intermediate nucleus for both the light and heavy neutrino decay processes. This provides a new theoretical tool for comparing and improving nuclear structure models. It also provides the connection to two-nucleon transfer experiments.

  20. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Vaisman, M.; Tomasulo, S.; Masuda, T.; Lang, J. R.; Faucher, J.; Lee, M. L. [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511 (United States)

    2015-02-09

    Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.

  1. Nuclear structure functions at a future electron-ion collider

    Science.gov (United States)

    Aschenauer, E. C.; Fazio, S.; Lamont, M. A. C.; Paukkunen, H.; Zurita, P.

    2017-12-01

    The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction x —robust experimental constraints below x ˜10-2 at low resolution scale Q2 are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in Deep Inelastic Scattering (DIS) measurements down to x ˜10-5 at perturbative resolution scales. The construction of an electron-ion collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-x region in much greater detail. In the present paper we simulate the extraction of the nuclear structure functions from measurements of inclusive and charm reduced cross sections at an EIC. The potential constraints are studied by analyzing simulated data directly in a next-to-leading order global fit of nuclear Parton Distribution Functions based on the recent EPPS16 analysis. A special emphasis is placed on studying the impact an EIC would have on extracting the nuclear gluon parton distribution function, the partonic component most prone to nonlinear effects at low Q2. In comparison to the current knowledge, we find that the gluon parton distribution function can be measured at an EIC with significantly reduced uncertainties.

  2. Equidistant structure and effective nucleon mass in nuclear matter

    International Nuclear Information System (INIS)

    Tezuka, Hirokazu.

    1981-11-01

    The effective nucleon mass of the Equidistant Multi-Layer Structure (EMULS) is discussed self-consistently. In the density region where the Fermi gas state in nuclear matter is unstable against the density fluctuation, the EMULS gives lower binding energy. It is, however, shown that such a structure with an ordinary nucleon mass collapses due to too strong attraction. We point out that such a collapse can be avoided by taking account of an effective nucleon mass affected by the localization of nucleons. (author)

  3. SUMO modification through rapamycin-mediated heterodimerization reveals a dual role for Ubc9 in targeting RanGAP1 to nuclear pore complexes

    International Nuclear Information System (INIS)

    Zhu Shanshan; Zhang Hong; Matunis, Michael J.

    2006-01-01

    SUMOs (small ubiquitin-related modifiers) are eukaryotic proteins that are covalently conjugated to other proteins and thereby regulate a wide range of important cellular processes. The molecular mechanisms by which SUMO modification influences the functions of most target proteins and cellular processes, however, remain poorly defined. A major obstacle to investigating the effects of SUMO modification is the availability of a system for selectively inducing the modification or demodification of an individual protein. To address this problem, we have developed a procedure using the rapamycin heterodimerizer system. This procedure involves co-expression of rapamycin-binding domain fusion proteins of SUMO and candidate SUMO substrates in living cells. Treating cells with rapamycin induces a tight association between SUMO and a single SUMO substrate, thereby allowing specific downstream effects to be analyzed. Using RanGAP1 as a model SUMO substrate, the heterodimerizer system was used to investigate the molecular mechanism by which SUMO modification targets RanGAP1 from the cytoplasm to nuclear pore complexes (NPCs). Our results revealed a dual role for Ubc9 in targeting RanGAP1 to NPCs: In addition to conjugating SUMO-1 to RanGAP1, Ubc9 is also required to form a stable ternary complex with SUMO-1 modified RanGAP1 and Nup358. As illustrated by our studies, the rapamycin heterodimerizer system represents a novel tool for studying the molecular effects of SUMO modification

  4. Seismic site characterization for nuclear structures and power plants

    International Nuclear Information System (INIS)

    Boominathan, A.

    2004-01-01

    Seismic site characterization is carried out for the construction of nuclear structures and power plants in earthquake-prone areas to establish the occurrence of severe seismic hazards such as tectonic rupture, surface faulting, large scale liquefaction, sliding and seismic settlement which may alter the overall stability of the site. Seismic characterization is required to finalize the design earthquake parameters including choosing input seismic data. As a part of the investigation, measurements of relevant dynamic parameters both in laboratory and in situ have been made for carrying out dynamic soil structure interaction analysis, for determination of dynamic deformation, seismic settlement and dynamic response spectrum of the site, and for calculating dynamic earth pressure acting on retaining structures. We discuss here the seismic investigation components and methods, measurement of P- and S- wave velocities in the field and estimation of important dynamic parameters such as maximum shear modulus, modulus reduction curve, damping ratio, seismic site classification, predominant site period, liquefaction analysis through case studies for nuclear structures at Kalpakkam and Kudankulam and power plant structures at New Delhi and Konaseema. (author)

  5. Non-empirical energy density functional for the nuclear structure

    International Nuclear Information System (INIS)

    Rot ival, V.

    2008-09-01

    The energy density functional (EDF) formalism is the tool of choice for large-scale low-energy nuclear structure calculations both for stable experimentally known nuclei whose properties are accurately reproduced and systems that are only theoretically predicted. We highlight in the present dissertation the capability of EDF methods to tackle exotic phenomena appearing at the very limits of stability, that is the formation of nuclear halos. We devise a new quantitative and model-independent method that characterizes the existence and properties of halos in medium- to heavy-mass nuclei, and quantifies the impact of pairing correlations and the choice of the energy functional on the formation of such systems. These results are found to be limited by the predictive power of currently-used EDFs that rely on fitting to known experimental data. In the second part of this dissertation, we initiate the construction of non-empirical EDFs that make use of the new paradigm for vacuum nucleon-nucleon interactions set by so-called low-momentum interactions generated through the application of renormalization group techniques. These soft-core vacuum potentials are used as a step-stone of a long-term strategy which connects modern many-body techniques and EDF methods. We provide guidelines for designing several non-empirical models that include in-medium many-body effects at various levels of approximation, and can be handled in state-of-the art nuclear structure codes. In the present work, the first step is initiated through the adjustment of an operator representation of low-momentum vacuum interactions using a custom-designed parallel evolutionary algorithm. The first results highlight the possibility to grasp most of the relevant physics for low-energy nuclear structure using this numerically convenient Gaussian vertex. (author)

  6. Mathematical analysis of compressive/tensile molecular and nuclear structures

    Science.gov (United States)

    Wang, Dayu

    Mathematical analysis in chemistry is a fascinating and critical tool to explain experimental observations. In this dissertation, mathematical methods to present chemical bonding and other structures for many-particle systems are discussed at different levels (molecular, atomic, and nuclear). First, the tetrahedral geometry of single, double, or triple carbon-carbon bonds gives an unsatisfying demonstration of bond lengths, compared to experimental trends. To correct this, Platonic solids and Archimedean solids were evaluated as atoms in covalent carbon or nitrogen bond systems in order to find the best solids for geometric fitting. Pentagonal solids, e.g. the dodecahedron and icosidodecahedron, give the best fit with experimental bond lengths; an ideal pyramidal solid which models covalent bonds was also generated. Second, the macroscopic compression/tension architectural approach was applied to forces at the molecular level, considering atomic interactions as compressive (repulsive) and tensile (attractive) forces. Two particle interactions were considered, followed by a model of the dihydrogen molecule (H2; two protons and two electrons). Dihydrogen was evaluated as two different types of compression/tension structures: a coaxial spring model and a ring model. Using similar methods, covalent diatomic molecules (made up of C, N, O, or F) were evaluated. Finally, the compression/tension model was extended to the nuclear level, based on the observation that nuclei with certain numbers of protons/neutrons (magic numbers) have extra stability compared to other nucleon ratios. A hollow spherical model was developed that combines elements of the classic nuclear shell model and liquid drop model. Nuclear structure and the trend of the "island of stability" for the current and extended periodic table were studied.

  7. Configuration management and load monitoring procedures for nuclear plant structures

    International Nuclear Information System (INIS)

    Chu, S.L.; Skaczylo, A.T.

    1990-01-01

    This paper describes a computer-aided engineering tool called the Load Monitoring System (LMS) that was proven effective for monitoring floor framing, loads, and structural integrity. The system links structural analysis, design investigation, and reporting and automated drafting programs with a Data Base Management System (DBMS). It provides design engineers with a powerful tool for quickly incorporating, tracking, and assessing load revisions and determining effects on steel floor framing members and connections, thereby helping to reduce design man-hours, minimize the impact of structural modifications, and maintain and document the design baseline. The major benefit to utilities are the reduction in engineering costs, assistance with plant configuration management, and assurance of structural safety throughout the operating life of a nuclear plant and at evaluation for license renewal. (orig./HP)

  8. Nuclear fuel cycle bringing about opportunity for industrial structure conversion

    International Nuclear Information System (INIS)

    Nakamura, Taiki

    1991-01-01

    Three facilities of nuclear fuel cycle, that is, uranium enrichment, fuel reprocessing and low level radioactive waste storage and burying, are being constructed by electric power industry in Rokkasho Village, Kamikita County, Aomori Prefecture. These are the large scale project of the total investment of 1.2 trillion yen. It is expected that the promotion of this project exerts not a little effect to the social economy of the surrounding districts. Agency of Natural Resources and Energy, Ministry of International Trade and Industry, carried out the social environment survey on the location of nuclear fuel cycle facilities. In this report, the outline of the economical pervasive effect due to the construction and operation of the three facilities in the report of this survey is described. The method of survey and the organization, the outline of three nuclear fuel cycle facilities, the economical pervasive effect, the effect to the local social structure, and the direction of arranging occupation, residence and leisure accompanying the location of three nuclear fuel cycle facilities are reported. (K.I.)

  9. Nuclear matter descriptions including quark structure of the hadrons

    International Nuclear Information System (INIS)

    Huguet, R.

    2008-07-01

    It is nowadays well established that nucleons are composite objects made of quarks and gluons, whose interactions are described by Quantum chromodynamics (QCD). However, because of the non-perturbative character of QCD at the energies of nuclear physics, a description of atomic nuclei starting from quarks and gluons is still not available. A possible alternative is to construct effective field theories based on hadronic degrees of freedom, in which the interaction is constrained by QCD. In this framework, we have constructed descriptions of infinite nuclear matter in relativistic mean field theories taking into account the quark structure of hadrons. In a first approach, the in medium modifications of mesons properties is dynamically obtained in a Nambu-Jona-Lasinio (NJL) quark model. This modification is taken into account in a relativistic mean field theory based on a meson exchange interaction between nucleons. The in-medium modification of mesons masses and the properties of infinite nuclear matter have been studied. In a second approach, the long and short range contributions to the in-medium modification of the nucleon are determined. The short range part is obtained in a NJL quark model of the nucleon. The long range part, related to pions exchanges between nucleons, has been determined in the framework of Chiral Perturbation theory. These modifications have been used to constrain the couplings of a point coupling relativistic mean field model. A realistic description of the saturation properties of nuclear matter is obtained. (author)

  10. Effect of a gap opening on the conductance of graphene with magnetic barrier structures

    Science.gov (United States)

    Esmailpour, Mohammad

    2018-04-01

    In the present study Klein tunneling in a single-layer gapped graphene was investigated by transfer matrix method under normal magnetic field for one and two magnetic barriers. Calculations show that electron transmission through a magnetic barrier is deflected to positive angles and reduces as the magnitude of magnetic field and especially the energy gap increases. This reduction is even more significant in larger fields so that after reaching a specific value of energy gap, an effective confinement for fermions and suppression of Klein tunneling is reached particularly in normal incidence and the conductance becomes zero. Unlike one barrier, the process of tunneling through two magnetic barriers induces symmetric transmission probability versus the incident angle; even, for lower energy gaps, electron transmission probability increases which in turn reduces total conductance via proper changes in the value of the magnetic field and energy gap. In general, it is concluded that confining electrons in asymmetric transmission through one barrier is conducted better than two barriers.

  11. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1993-01-01

    This is a progress report on activities of the Washington University group in nuclear reaction studies for the period Sept 1, 1992 to Aug 31, 1993. This group has a research program which touches five areas of nuclear physics: nuclear structure studies at high spin; studies at the interface between structure and reactions; production and study of hot nuclei; reaction mechanism studies; development and use of novel techniques and instrumentation in the above areas of research. Specific activities of the group include in part: superdeformation in 82 Sr; structure of and identical bands in 182 Hg and 178 Pt; a highly deformed band in 136 Pm; particle decay of the 164 Yb compound nucleus; fusion reactions; proton evaporation; two-proton decay of 12 O; modeling and theoretical studies; excited 16 O disassembly into four alpha particles; 209 Bi + 136 Xe collisions at 28.2 MeV/amu; and development work on 4π solid angle gamma detectors, and x-ray detectors

  12. Evaluation of network structures and protocols for nuclear-specific applications

    International Nuclear Information System (INIS)

    Zahedi, P.

    2008-01-01

    The evaluation of industrial implementations of network structures associated with nuclear-specific applications is the main focus of this paper. Establishing numerous network structures currently used in nuclear industry, this project analyzes the functionality and reliability of different structures. The communication structures studied in this paper include Fieldbus and Modbus Communication Protocols, Object Linking and Embedding process control (OPC), Dynamic Data Exchange (DDE) and Net-DDE. This paper focuses on identifying the potential problems in applying various network structures to nuclear industry to enable a nuclear-specific network structure to be developed for the fast growing nuclear industry. (author)

  13. Recognition structure of semipalatinsk residents caused by nuclear explosion tests

    International Nuclear Information System (INIS)

    Hirabayashi, Kyoko; Satoh, Kenichi; Ohtaki, Megu; Muldagaliyev, T.; Apsalikov, K.; Kawano, Noriyuki

    2012-01-01

    Authors' team of Hiroshima University and Scientific Research Institute of Radiation Medicine and Ecology (Kazakhstan) has been investigating the health state, exposure route, contents and mental effect of nuclear explosion tests of Semipalatinsk residents through their witness and questionnaire since 2002, to elucidate the humanistic damage of nuclear tests. Reported here is the recognition structure in the title statistically analyzed with use of frequently spoken words in the witness. The audit was performed in 2002-2007 to 994 residents who had experienced ground explosion tests during the period from 1949 to 1962 and were living in 26 villages near the old test site. Asked questions concerning nuclear tests involved such items as still unforgettable matters, dreadful events, regretting things, thought about the test, requests; and matters about themselves, their family, close friends and anything. The frequency of the test site-related words heard in the interview were analyzed with hierarchical clustering and multi-dimensional scaling with a statistic software R for computation and MeCab for morphological analysis. Residents' recognition was found to be of two structures of memory at explosion tests and anger/dissatisfaction/anxiety to the present state. The former contained the frequent words of mushroom cloud, flash, blast, ground tremble and outdoor evacuation, and the latter, mostly anxiety about health of themselves and family. Thus residents have had to be confronted with uneasiness of their health even 20 years after the closure of the test site. (T.T.)

  14. Simulation Analysis of a Strip Dipole Excited Electromagnetic Band-Gap (EBG) Structure

    Science.gov (United States)

    2015-07-01

    ℎ) �1− 1 +1 (sin)2� . (18) The angle 2 can be calculated using Snell’s law of refraction and the angle of incidence: 2...led to a wider 1 dBi realized gain bandwidth. The pattern distortions in the H-plane were also not as prevalent in the wide-gap EBG as they were in...to the dipole lengths would require a trial and error method or optimization, there still is not much of a reason to use a wider gap for the EBG

  15. Investigation of knowledge structure of nuclear data evaluation code

    International Nuclear Information System (INIS)

    Uenaka, Junji; Kambayashi, Shaw

    1988-08-01

    In this report, investigation results of knowledge structure in a nuclear data evaluation code are described. This investigation is related to the natural language processing and the knowledge base in the research theme of Human Acts Simulation Program (HASP) begun at the Computing Center of JAERI in 1987. By using a machine translation system, an attempt has been made to extract a deep knowledge from Japanese sentences which are equivalent to a FORTRAN program CASTHY for nuclear data evaluation. With the knowledge extraction method used by the authors, the verification of knowledge is more difficult than that of the prototyping method in an ordinary AI technique. In the early stage of building up a knowledge base system, it seems effective to extract and examine knowledge fragments of limited objects. (author)

  16. Nuclear-structure studies of exotic nuclei with MINIBALL

    Science.gov (United States)

    Butler, P. A.; Cederkall, J.; Reiter, P.

    2017-04-01

    High-resolution γ-ray spectroscopy has been established at ISOLDE for nuclear-structure and nuclear-reaction studies with reaccelerated radioactive ion beams provided by the REX-ISOLDE facility. The MINIBALL spectrometer comprises 24 six-fold segmented, encapsulated high-purity germanium crystals. It was specially designed for highest γ-ray detection efficiency which is advantageous for low-intensity radioactive ion beams. The MINIBALL array has been used in numerous Coulomb-excitation and transfer-reaction experiments with exotic ion beams of energies up to 3 MeV A-1. The physics case covers a wide range of topics which are addressed with beams ranging from neutron-rich magnesium isotopes up to heavy radium isotopes. In the future the HIE-ISOLDE will allow the in-beam γ-ray spectroscopy program to proceed with higher secondary-beam intensity, higher beam energy and better beam quality.

  17. Coexistence of classical and quantum plasmonics in large plasmonic structures with subnanometer gaps

    DEFF Research Database (Denmark)

    Kadkhodazadeh, Shima; Wagner, Jakob Birkedal; Kneipp, Harald

    2013-01-01

    Large metal nanostructures with subnanometer interparticle separations (gaps) can provide extremely high local fields and are of particular interest in surface enhanced spectroscopy, as well as for basic understanding of plasmonics. In this experimental electron energy loss study, we monitor the ...

  18. Optical study of the band structure of wurtzite GaP nanowires

    KAUST Repository

    Assali, S.

    2016-07-25

    We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140–2.164–2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature-dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap of ∼2.190 eV and to a resonant state associated with the γ-line ∼80 meV above the Γ8C conduction band edge.

  19. Structural modification and band gap engineering of sol–gel dip ...

    Indian Academy of Sciences (India)

    2016-11-03

    Nov 3, 2016 ... ... absorption edge in the near ultra-violet region got red-shifted with annealing. The calculated values of optical energy gap of the samples showed a decrease with heat treatment due to the improvement in crystallinity during annealing and hence the subsequent decrease in quantum size effect. Keywords.

  20. Subharmonic energy gap structure in the Josephson radiation at 35 GHz from a superconducting thin-film microbridge

    DEFF Research Database (Denmark)

    Hansen, Jørn Bindslev; Levinsen, M. T.; Lindelof, Poul Erik

    1979-01-01

    Nonresonant detection of the Josephson radiation 35 GHz from a superconducting thin-film microbridge is reported. The high frequency and the accuracy of these measurements lead to a new important observation: subharmonic energy gap structure in the detected integral power. The maximum integral po...... power measured was as large as 8×10−11 W. Applied Physics Letters is copyrighted by The American Institute of Physics....

  1. The maintenance optimization of structural components in nuclear power plants

    International Nuclear Information System (INIS)

    Bryla, P.; Ardorino, F.; Aufort, P.; Jacquot, J.P.; Magne, L.; Pitner, P.; Verite, B.; Villain, B.; Monnier, B.

    1997-10-01

    An optimization process, called 'OMF-Structures', is developed by Electricite de France (EDF) in order to extend the current 'OMF' Reliability Centered Maintenance to piping structural components. The Auxiliary Feedwater System of a 900 MW French nuclear plant has been studied in order to lay the foundations of the method. This paper presents the currently proposed principles of the process. The principles of the OMF-Structures process include 'Risk-Based Inspection' concepts within an RCM process. Two main phases are identified: The purpose of the first phase is to select the risk-significant failure modes and associated elements. This phase consists of two major steps: potential consequences evaluation and reliability performance evaluation. The second phase consists of the definition of preventive maintenance programs for piping elements that are associated with risk-significant failure modes. (author)

  2. Nuclear structure and nuclear reaction aspects of Faessler and Greiner's rotation-vibration coupling theory

    International Nuclear Information System (INIS)

    Aspelund, O.

    In the nuclear structure part, the foundations of Faessler and Greiner's rotation-vibration coupling theory are reviewed, whereafter an alternative derivation of Faessler and Greiner's Hamiltonian is presented. A non-spherical quadrupole phonon number N is defined and used in the matrix elements reported for odd-even/even-odd nuclei. These matrix elements are shown to evince oblate-prolate effects that can be exploited for assessing the signs of quadrupole deformations. In the nuclear reaction part, the wave functions emerging from the structure part are applied in a complete and consistent description of elastic and inelastic particle scattering, one-nucleon transfer, and particle/γ-ray angular correlations. The intentions are to demonstrate that anomolous angular distributions and 1=2 j-effects observed in one-nucleon transfer are interrelated phenomena, that can be satisfactorily explained in terms of the elementary vibrational excitation modes inherent in Faessler and Greiner's theory. The latter is regarded as a non-spherical approach to the theory of the quadrupole component of the nuclear potential energy surface. (Auth.)

  3. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Na; Zhu, Yongqun; Lu, Qiuhe; Hu, Liyan; Zheng, Yuqing; Shao, Feng (NIBS-China); (Zhejiang)

    2012-10-10

    Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

  4. Nuclear structure studies with INGA at IUAC and future possibilities

    International Nuclear Information System (INIS)

    Singh, R.P.

    2016-01-01

    Study of nuclear structure exhibits a wide variety of modes of nuclear excitations. The various modes of excitations reflect different underlying structures nuclei adopt to for a given situation of spin, iso-spin and excitation energy. Trying to understand and reconcile these large variety of underlying structures (and symmetries) in a finite quantal system, like nuclei, is of great interest to physicists. The gamma ray spectrometer called Indian National Gamma detector Array (INGA) (a national collaboration) has given further impetus to these studies due to enhanced photo-peak detection efficiency for gamma rays. In recent years our group in collaboration with universities and institutes have probed the various dynamical symmetries like chirality, shears and gamma bands built over excited configurations. I would discuss some of the recent results from these studies. Further, at IUAC we are working on combining the INGA spectrometer with our hybrid gas-filled mass analyser HYRA for study of heavy nuclei in the forthcoming INGA-HYRA campaign. Some of these developments would also be discussed

  5. Structural integrity evaluation of PWR nuclear reactor pressure vessels

    International Nuclear Information System (INIS)

    Cruz, Julio R.B.; Mattar Neto, Miguel

    1999-01-01

    The reactor pressure vessel (RPV) is the most important structural component of a PWR nuclear power plant. It contains the reactor core and is the main component of the primary system pressure boundary, the system responsible for removing the heat generated by the nuclear reactions. It is considered not replaceable and, therefore, its lifetime is a key element to define the plant life as a whole. Three critical issues related to the reliability of the RPV structural integrity come out by reason of the radiation damage imposed to the vessel material during operation. These issues concern the definition of pressure versus temperature limits for reactor heatup and cooldown, pressurized thermal shock evaluation and assessment of reactor vessels with low upper shelf Charpy impact energy levels. This work aims to present the major aspects related to these topics. The requirements for preventing fracture of the RPV are reviewed as well as the available technology for assessing the safety margins. For each mentioned problem, the several steps for structural integrity evaluation are described and the analysis methods are discussed. (author)

  6. Seismic margin analysis technique for nuclear power plant structures

    International Nuclear Information System (INIS)

    Seo, Jeong Moon; Choi, In Kil

    2001-04-01

    In general, the Seismic Probabilistic Risk Assessment (SPRA) and the Seismic Margin Assessment(SAM) are used for the evaluation of realistic seismic capacity of nuclear power plant structures. Seismic PRA is a systematic process to evaluate the seismic safety of nuclear power plant. In our country, SPRA has been used to perform the probabilistic safety assessment for the earthquake event. SMA is a simple and cost effective manner to quantify the seismic margin of individual structural elements. This study was performed to improve the reliability of SMA results and to confirm the assessment procedure. To achieve this goal, review for the current status of the techniques and procedures was performed. Two methodologies, CDFM (Conservative Deterministic Failure Margin) sponsored by NRC and FA (Fragility Analysis) sponsored by EPRI, were developed for the seismic margin review of NPP structures. FA method was originally developed for Seismic PRA. CDFM approach is more amenable to use by experienced design engineers including utility staff design engineers. In this study, detailed review on the procedures of CDFM and FA methodology was performed

  7. Nuclear Structure Group annual progress report June 1974 -May 1975

    International Nuclear Information System (INIS)

    1975-06-01

    This is the first annual progress report of the Nuclear Structure Group of the University of Birmingham. The introduction lists the main fields of study of the Group as: polarisation penomena and optical model studies using 3 He and 4 He probes; photonuclear physics; heavy-ion physics; and K- meson physics. The programme is related to particle accelerators at Birmingham, Oxford, Harwell and the Rutherford Laboratory. The body of the report consists of summaries of 38 experiments undertaken by members of the Group. The third section contains 10 notes on instrumentation topics. Appendices contain lists of (a) personnel, (b) papers published or submitted during the period. (U.K.)

  8. Design and structural calculation of nuclear power plant mechanical components

    International Nuclear Information System (INIS)

    Amaral, J.A.R. do

    1986-01-01

    The mechanical components of a nuclear power plant must show high quality and safety due to the presence of radioactivity. Besides the perfect functioning during the rigid operating conditions, some postulated loadings are foreseen, like earthquake and loss of coolant accidents, which must be also considered in the design. In this paper, it is intended to describe the design and structural calculations concept and development, the interactions with the piping and civil designs, as well as their influences in the licensing process with the authorities. (Author) [pt

  9. Grain boundary engineering for structure materials of nuclear reactors

    Science.gov (United States)

    Tan, L.; Allen, T. R.; Busby, J. T.

    2013-10-01

    Grain boundary engineering (GBE), primarily implemented by thermomechanical processing, is an effective and economical method of enhancing the properties of polycrystalline materials. Among the factors affecting grain boundary character distribution, literature data showed definitive effect of grain size and texture. GBE is more effective for austenitic stainless steels and Ni-base alloys compared to other structural materials of nuclear reactors, such as refractory metals, ferritic and ferritic-martensitic steels, and Zr alloys. GBE has shown beneficial effects on improving the strength, creep strength, and resistance to stress corrosion cracking and oxidation of austenitic stainless steels and Ni-base alloys.

  10. Grain boundary engineering for structure materials of nuclear reactors

    International Nuclear Information System (INIS)

    Tan, L.; Allen, T.R.; Busby, J.T.

    2013-01-01

    Grain boundary engineering (GBE), primarily implemented by thermomechanical processing, is an effective and economical method of enhancing the properties of polycrystalline materials. Among the factors affecting grain boundary character distribution, literature data showed definitive effect of grain size and texture. GBE is more effective for austenitic stainless steels and Ni-base alloys compared to other structural materials of nuclear reactors, such as refractory metals, ferritic and ferritic–martensitic steels, and Zr alloys. GBE has shown beneficial effects on improving the strength, creep strength, and resistance to stress corrosion cracking and oxidation of austenitic stainless steels and Ni-base alloys

  11. Structural design of nuclear reactor machinery and equipment

    International Nuclear Information System (INIS)

    Hara, Hideki

    1992-01-01

    Since the machinery, equipment and piping which compose nuclear power station facilities are diverse, when those are designed, consideration is given sufficiently to the objective of use and the importance of the object machinery and equipment so that those can maintain the soundness over the design life. In this report, on the contents and the design standard in the design techniques for nuclear reactor machinery and equipment, the way of thinking is shown, taking an example of reactor pressure vessel which is stipulated as the vessel kind 1 in the 'Technical standard of structures and others regarding nuclear facilities for electric power generation', Notice No. 501 of the Ministry of International Trade and Industry. The reactor pressure vessel of 1350 MWe improved type BWR (ABWR) is used under the condition of 87.9 kg/cm 2 and 302 degC, and the inside diameter is about 7.2 m, the inside height is about 21 m, and the wall thickness is about 170 mm. The design standard for reactor pressure vessels and its way of thinking, breakdown prevention design and the design techniques for reactor pressure vessels are described. (K.I.)

  12. Penetration effect in internal conversion and nuclear structure

    International Nuclear Information System (INIS)

    Listengarten, M.A.

    1978-01-01

    The conditions for the appearance of the anomalous internal conversion coefficients (ICC) are considered, when the contribution of the penetration matrix element (PME) is of the order of or larger than the main part of the conversion matrix element. The experimental magnitudes of the nuclear PME agree well with those calculated in the framework of simple nuclear models, provided the magnitude of PME is not decreased due to the model -dependent selection rules. The magnitude of the anomaly ( lanbda parameter ) is compared with the exclusion factor of γ-transition relative to the Weisskopf estimation. The better is the model of the nucleus the weaker is the dependence of the lambda magnitude on the exclusion factor. ICC coefficients might be anomalous for those γ-transitions for which the exclusion factor calculated in the framework of more rigorous model are of the order of unity. In the ''ideal'' model of nucleus completely adequate to the true nuclear structure the dependence of the lambda penetration parameter on the exclusion factor vanishes

  13. Direct nuclear reactions and the structure of atomic nuclei

    International Nuclear Information System (INIS)

    Osterfeld, F.

    1985-01-01

    The present thesis deals with two different aspects of direct nuclear reactions, namely on the one hand with the microscopic calculation of the imaginary optical potential for the elastic nucleon-nucleus scattering as well as on the other hand with the microscopic analysis of giant magnetic resonances in atomic nuclei which are excited by (p,n) charge-exchange reactions. In the first part of the thesis the imaginary part of the optical potential for the elastic proton- and neutron-nucleus scattering is microscopically calculated in the framework of the so called nuclear-structure approximation to the optical potential. The calculations are performed in the Feshbach formalism in second-order perturbation theory corresponding to an effective projectile-target-nucleon interaction. In the second part of this thesis in the framework of microscopic nuclear models a complete analysis of different A(p,n)B charge-exchange reactions at high incident energies 160 MeV 90 Zr(p,n) reaction three collective spin-isospin resonances could be uniquely identified. (orig./HSI) [de

  14. Investigation of series resistance and surface states in Au/n - GaP structures

    International Nuclear Information System (INIS)

    Kiymaz, A.; Onal, B.; Ozer, M.; Acar, S.

    2009-01-01

    The variation in series resistance and surface state density of Au/n - GaP Schottky diodes have been systematically investigated at room temperature by using capacitance-voltage C-V and conductance-voltage G/w-V measurements techniques. The C-V and G/w-V characteristics of these devices were investigated by considering series resistance effects in a wide frequency range. It is shown that the capacitance of the Au/n - GaP Schottky diode decreases with increasing frequency. It is assumed that the surface states were responsible for this behaviour. The distribution profile of Rs-V gives a peak in the depletion region at low frequencies and disappears with increasing frequencies

  15. Tunneling conductance in a gapped graphene-based superconducting structure: Case of massive Dirac electrons

    International Nuclear Information System (INIS)

    Soodchomshom, Bumned; Tang, I-Ming; Hoonsawat, Rassmidara

    2009-01-01

    The tunneling conductance in a NG/SG graphene junction in which the graphene was grown on a SiC substrate is simulated. The carriers in the normal graphene (NG) and the superconducting graphene (SG) are treated as massive relativistic particles. It is assumed that the Fermi energy in the NG and SG are E FN ∼400 meV and E FS ∼400 meV+U, respectively. Here U is the electrostatic potential from the superconducting gate electrode. It is seen that the Klein tunneling disappears in the case where a gap exist in the energy spectrum. As U→∞, the zero bias normalized conductance becomes persistent at a minimal value of G/G 0 ∼1.2. The normalized conductance G/G 0 is found to depend linearly on U with constant slope of α=2/(E FN -mv F 2 )∼7.4, where 2mv F 2 is the size of the gap Δ opening up in the energy spectrum of the graphene grown on the SiC substrate. It is found that G/G 0 ≅2+αU for potentials in the range -270 meV 0 ∼2Θ(U). This last behavior indicates that a NG/SG junction made with gapped graphene could be used as a nano switch having excellent characteristics.

  16. Discussion on organization structure system of nuclear power projects in China

    International Nuclear Information System (INIS)

    Wang Zhi

    2011-01-01

    With the development of the nuclear power industry in China, several AE companies were born and now play a major role in building nuclear power projects in China and overseas. After studying current organization structure systems of all nuclear power AE companies in China and comparing with successful foreign ones, this paper proposes some approaches to optimize the structure. (author)

  17. γ-rays as a probe to study nuclear dynamics and nuclear structure at intermediate energies

    International Nuclear Information System (INIS)

    Schutz, Y.

    1987-01-01

    The usefulness of gamma rays in nuclear physics is reviewed, and it is shown how they offer insight into the structure and damping of giant resonances, and how they can be used as an isospin filter. Results from inclusive and exclusive experiments at GANIL are discussed. It is stressed that although the production of high energy gamma rays in heavy ion reactions between 30 MeV/A and 86 MeV/A is understood qualitatively, most models fail in being more quantitative

  18. ROR nuclear receptors: structures, related diseases, and drug discovery.

    Science.gov (United States)

    Zhang, Yan; Luo, Xiao-yu; Wu, Dong-hai; Xu, Yong

    2015-01-01

    Nuclear receptors (NRs) are ligand-regulated transcription factors that regulate metabolism, development and immunity. The NR superfamily is one of the major classes of drug targets for human diseases. Retinoic acid receptor-related orphan receptor (ROR) α, β and γ belong to the NR superfamily, and these receptors are still considered as 'orphan' receptors because the identification of their endogenous ligands has been controversial. Recent studies have demonstrated that these receptors are regulated by synthetic ligands, thus emerge as important drug targets for the treatment of multiple sclerosis, rheumatoid arthritis, psoriasis, etc. Studying the structural basis and ligand development of RORs will pave the way for a better understanding of the roles of these receptors in human diseases. Here, we review the structural basis, disease relevance, strategies for ligand identification, and current status of development of therapeutic ligands for RORs.

  19. Structural and conformational study of polysaccharides by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Bossennec, Veronique

    1989-01-01

    As some natural polysaccharides are involved in important biological processes, the use of nuclear magnetic resonance appears to be an adapted mean to determine their structure-activity relationship and is therefore the object of this research thesis. By using bi-dimensional proton-based NMR techniques, it is possible to identify minority saccharide units, to determine their conformation, and to identify units which they are bound to. The author reports the application of these methods to swine mucosa heparin, and to heparins displaying a high and low anticoagulant activity. The dermatan sulphate has also been studied, and the NMR analysis allowed some polymer structure irregularities to be identified. A molecular modelling of dermatan sulphate has been performed [fr

  20. Evaluated Nuclear Structure data file: a manual for preparation of data sets

    International Nuclear Information System (INIS)

    Ewbank, W.B.; Schmorak, M.R.

    1978-02-01

    A standard input format for nuclear structure data is described. The format is sufficiently structured that bulk data can be entered efficiently. At the same time, the structure is open-ended and can accommodate most measured or deduced quantities that yield nuclear structure information

  1. Seismic evaluation and strengthening of Bohunice nuclear power plant structures

    International Nuclear Information System (INIS)

    Shipp, J.G.; Short, S.A.; Grief, T.; Borov, V.; Kuzma, J.

    2001-01-01

    A seismic assessment and strengthening investigation is being performed for selected structures at the Bohunice V1 Nuclear Power Plant in Slovakia. Structures covered in this paper include the reactor building complex and the emergency generator station. The emergency generator station is emphasized in the paper as work is nearly complete while work on the reactor building complex is ongoing at this time. Seismic evaluation and strengthening work is being performed by a cooperative effort of Siemens and EQE along with local contractors. Seismic input is the interim Review Level Earthquake (horizontal peak ground acceleration of 0.3 g). The Bohunice V1 reactor building complex is a WWER 4401230 nuclear power plant that was originally built in the mid-1970s but had extensive seismic upgrades in 1991. Siemens has performed three dimensional dynamic analyses of the reactor building complex to develop seismic demand in structural elements. EQE is assessing seismic capacities of structural elements and developing strengthening schemes, where needed. Based on recent seismic response analyses for the interim Review Level Earthquake which account for soil-structure interaction in a rigorous manner, the 1991 seismic upgrade has been found to be inadequate in both member/connection strength and in providing complete load paths to the foundation. Additional strengthening is being developed. The emergency generator station was built in the 1970s and is a two-story unreinforced brick masonry (URM) shear wall building above grade with a one story reinforced concrete shear wall basement below grade. Seismic analyses and testing of the URM walls has been performed to assess the need for building strengthening. Required structural strengthening for in-plane forces consists of revised and additional vertical steel framing and connections, stiffening of horizontal roof bracing, and steel connections between the roof and supporting walls and pointing of two interior transverse URM

  2. Nuclear Structure Studies at the Future FAIR facility

    International Nuclear Information System (INIS)

    Rubio, Berta

    2010-01-01

    This article is intended to be an introduction to studies of nuclear structure at the future FAIR facility. It addresses interested readers not necessarily expert in the field. It outlines the physics aims and experiments to be carried out at FAIR in the field of nuclear structure and astrophysics. Starting with a brief description of what can be achieved in experiments with intense, high quality stable beams the article leads the reader to how beams of unstable radioactive nuclei will be produced and exploited at FAIR. The characteristics of the beams from the main separation device, the Super-FRS, are outlined and the limitations they impose on experiment are discussed. The various setups at the three experimental branches associated with the Super-FRS are described. The aims of the various experimental setups, how they complement each other and the physics they will address are all explained. The concept of the r-process of nucleosynthesis is outlined at the beginning and used as a running example of how useful it will be to be able to carry out experiments with beams of short-lived, exotic ions.

  3. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    Directory of Open Access Journals (Sweden)

    Brian J. Munroe

    2016-03-01

    Full Text Available We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG accelerator structure. Photonic band-gap (PBG structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox input and output cells, with input power of up to 4 MW from a klystron supplied via a TM_{01} mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87  MV/m at a breakdown probability of 1.19×10^{-1} per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90  MV/m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89  MV/m at a breakdown probability of 1.09×10^{-1} per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  4. Mechanics of a composite structure of GFRP insulators and superconductors with a gap

    International Nuclear Information System (INIS)

    Tamura, H.; Imagawa, S.; Nishimura, A.

    1997-01-01

    Superconducting coils in large scale magnet applications such as the Large Helical Device (LHD) are subjected to large electromagnetic force at the interfaces between conductors and electrical insulators. The insulators do not always contact the superconductor surfaces completely. This may cause a reduction of coil rigidity. Nonlinear behavior was observed in the compressive load-displacement curves in some experiments of coil packs. The nonlinear curves were found to be well fitted by an exponential function. We considered this nonlinearity as a surface contact problem and devised some analytical models to evaluate the rigidity reduction in terms of gap length. The results of this analysis also support the exponential function

  5. Extended analysis of the field-angle-dependent heat capacity of (TMTSF)2ClO4 toward identification of the superconducting gap structure

    International Nuclear Information System (INIS)

    Yonezawa, Shingo; Maeno, Yoshiteru; Jérome, Denis

    2013-01-01

    In this paper, we present detailed analyses of the field-angle dependence of the heat capacity of the quasi-one-dimensional superconductor (TMTSF) 2 ClO 4 with various models of superconducting gap structure. We clarify that the superconducting gap structure with line nodes at k y = ±0.25b * is the only structure that is consistent with our experiment, irrespective of the value of the anion gap. The observed field-angle dependence of the heat capacity indicates that two of the four nodes mainly contribute to the quasiparticle excitation

  6. Impact of structural aging on seismic risk assessment of reinforced concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Ellingwood, B.; Song, J.

    1996-03-01

    The Structural Aging Program is addressing the potential for degradation of concrete structural components and systems in nuclear power plants over time due to aging and aggressive environmental stressors. Structures are passive under normal operating conditions but play a key role in mitigating design-basis events, particularly those arising from external challenges such as earthquakes, extreme winds, fires and floods. Structures are plant-specific and unique, often are difficult to inspect, and are virtually impossible to replace. The importance of structural failures in accident mitigation is amplified because such failures may lead to common-cause failures of other components. Structural condition assessment and service life prediction must focus on a few critical components and systems within the plant. Components and systems that are dominant contributors to risk and that require particular attention can be identified through the mathematical formalism of a probabilistic risk assessment, or PRA. To illustrate, the role of structural degradation due to aging on plant risk is examined through the framework of a Level 1 seismic PRA of a nuclear power plant. Plausible mechanisms of structural degradation are found to increase the core damage probability by approximately a factor of two

  7. Probabilistic approaches to life prediction of nuclear plant structural components

    International Nuclear Information System (INIS)

    Villain, B.; Pitner, P.; Procaccia, H.

    1996-01-01

    In the last decade there has been an increasing interest at EDF in developing and applying probabilistic methods for a variety of purposes. In the field of structural integrity and reliability they are used to evaluate the effect of deterioration due to aging mechanisms, mainly on major passive structural components such as steam generators, pressure vessels and piping in nuclear plants. Because there can be numerous uncertainties involved in a assessment of the performance of these structural components, probabilistic methods. The benefits of a probabilistic approach are the clear treatment of uncertainly and the possibility to perform sensitivity studies from which it is possible to identify and quantify the effect of key factors and mitigative actions. They thus provide information to support effective decisions to optimize In-Service Inspection planning and maintenance strategies and for realistic lifetime prediction or reassessment. The purpose of the paper is to discuss and illustrate the methods available at EDF for probabilistic component life prediction. This includes a presentation of software tools in classical, Bayesian and structural reliability, and an application on two case studies (steam generator tube bundle, reactor pressure vessel). (authors)

  8. Probabilistic approaches to life prediction of nuclear plant structural components

    International Nuclear Information System (INIS)

    Villain, B.; Pitner, P.; Procaccia, H.

    1996-01-01

    In the last decade there has been an increasing interest at EDF in developing and applying probabilistic methods for a variety of purposes. In the field of structural integrity and reliability they are used to evaluate the effect of deterioration due to aging mechanisms, mainly on major passive structural components such as steam generators, pressure vessels and piping in nuclear plants. Because there can be numerous uncertainties involved in an assessment of the performance of these structural components, probabilistic methods provide an attractive alternative or supplement to more conventional deterministic methods. The benefits of a probabilistic approach are the clear treatment of uncertainty and the possibility to perform sensitivity studies from which it is possible to identify and quantify the effect of key factors and mitigative actions. They thus provide information to support effective decisions to optimize In-Service Inspection planning and maintenance strategies and for realistic lifetime prediction or reassessment. The purpose of the paper is to discuss and illustrate the methods available at EDF for probabilistic component life prediction. This includes a presentation of software tools in classical, Bayesian and structural reliability, and an application on two case studies (steam generator tube bundle, reactor pressure vessel)

  9. Challenges of structural materials for innovative nuclear systems in Europe

    International Nuclear Information System (INIS)

    Serrano, M.; Gomez-Briceno, D.

    2009-01-01

    New fusion and fission reactors for generation IV are envisaged to operate at conditions well above the actual ones for commercial fission reactors. This type of reactor combined a high operation temperature with a high neutron dose and an aggressive coolant, which imply new challenges for structural materials. One of the key issues to assure the safety and feasibility of these new nuclear systems is the selection of the structural materials, especially for in core components. Beside the differences between them, especially the amount of transmutation He in fusion reactors, similar structural materials have been selected. Some of the selected materials are well characterized at least at medium temperatures, as conventional ferritic/martensitic steels, but the qualification for higher temperatures is needed. For other materials, as ODS steels, there is a need for a complete characterization and qualification. In this paper a review of the operating conditions and selected structural materials for generation IV and fusion reactors within Europe is made. The needs for a complete characterization of these candidate materials are identified in terms of high temperature behaviour, radiation damage and coolant compatibility. (author)

  10. Universal correlations of nuclear observables and the structure of exotic nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.; Zamfir, N.V.

    1996-01-01

    Despite the apparent complexity of nuclear structural evolution, recent work has shown a remarkable underlying simplicity that is unexpected, global, and which leads to new signatures for structure based on the easiest-to-obtain data. As such they will be extremely valuable for use in the experiments with low intensity radioactive beams. Beautiful correlations based either on extrinsic variables such as N p N n or the P-factor or correlations between collective observables themselves have been discovered. Examples to be discussed include a tri-partite classification of structural evolution, leading to a new paradigm that discloses certain specific classes of nuclei, universal trajectories for B(E2: w 1 + → 0 1 + ) values and their use in extracting hexadecapole deformations from this observable alone, the use of these B(E2) values to identify shell gaps and magic numbers in exotic nuclei, the relationship of β and γ deformations, and single nucleon separation energies. Predictions for nuclei far off stability by interpolation will also be discussed

  11. Revisiting the coupled-mass system and analogy with a simple band gap structure

    International Nuclear Information System (INIS)

    Levesque, L

    2006-01-01

    A great deal of insight can be gained from the analysis of coupled masses connected to springs in order to understand better the origin of band gaps in physical systems. The approach is based on the application of the superposition principle for finding the general solution in simple mechanical systems involving functions, which vary periodically with time. Graphs show that sums of periodic functions oscillating at different frequencies lead to an exchange of energy from one oscillator to another in a simple mechanical system of three objects connected by identical springs. A system of a large number of masses connected to springs having the same spring constant K is then considered and compared with a system in which the spring constants alternate from K to another value G when connecting one mass to another. Using the results found from the mechanical systems, an analogy of charge oscillations excited on both uniform and corrugated surfaces is presented. The results obtained attempt to expand understanding of the origin of the band gap occurring in some systems involving periodic motions

  12. Nuclear structure of 94,95Mo at high spins

    International Nuclear Information System (INIS)

    Kharraja, B.; Ghugre, S.S.; Garg, U.; Janssens, R.V.; Carpenter, M.P.; Crowell, B.; Khoo, T.L.; Lauritsen, T.; Nisius, D.; Reviol, W.; Mueller, W.F.; Riedinger, L.L.; Kaczarowski, R.

    1998-01-01

    The high-spin level structures of 94,95 Mo (N=52,53) have been investigated via the 65 Cu( 36 S, αp2n) 94 Mo and 65 Cu( 36 S, αpn) 95 Mo reactions at 142 MeV. The level schemes have been extended up to spin J∼19ℎ and excitation energies E x ∼12 MeV. Spherical shell-model calculations have been performed and compared with the experimental energy levels. The level structure of 94 Mo exhibits a single-particle nature and the higher-angular-momentum states are dominated by the excitation of a g 9/2 neutron across the N=50 shell gap. The level sequences observed in 95 Mo have been interpreted on the basis of the spherical shell model and weak coupling of a d 5/2 or a g 7/2 neutron to the 94 Mo core. copyright 1998 The American Physical Society

  13. [Nuclear Structure Research] at the Triangle Universities Nuclear Laboratory: Annual report No. 27, 1 September 1987--31 August 1988

    International Nuclear Information System (INIS)

    1988-01-01

    This report contains papers in the following topics: Fundamental symmetries in the nucleus; Dynamics of few-nucleon systems; Tensor forces in light nuclei; nucleon-nucleus interactions mechanisms; Nuclear structure and reactions; and Development and instrumentation

  14. Effects of structural nonlinearity and foundation sliding on probabilistic response of a nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Alidad, E-mail: sahashem@bechtel.com; Elkhoraibi, Tarek; Ostadan, Farhang

    2015-12-15

    Highlights: • Probabilistic SSI analysis including structural nonlinearity and sliding are shown. • Analysis is done for a soil and a rock site and probabilistic demands are obtained. • Structural drift ratios and In-structure response spectra are evaluated. • Structural nonlinearity significantly impacts local demands in the structure. • Sliding generally reduces seismic demands and can be accommodated in design. - Abstract: This paper examines the effects of structural nonlinearity and foundation sliding on the results of probabilistic structural analysis of a typical nuclear structure where structural nonlinearity, foundation sliding and soil-structure interaction (SSI) are explicitly included. The evaluation is carried out for a soil and a rock site at 10{sup 4}, 10{sup 5}, and 10{sup 6} year return periods (1E − 4, 1E − 5, and 1E − 6 hazard levels, respectively). The input motions at each considered hazard level are deaggregated into low frequency (LF) and high frequency (HF) motions and a sample size of 30 is used for uncertainty propagation. The statistical distribution of structural responses including story drifts, and in-structure response spectra (ISRS) as well as foundation sliding displacements are examined. The probabilistic implementation of explicit structural nonlinearity and foundation sliding in combination with the SSI effects are demonstrated using nonlinear response history analysis (RHA) of the structure with the foundation motions obtained from elastic SSI analyses, which are applied as input to fixed-base inelastic analyses. This approach quantifies the expected structural nonlinearity and sliding for the particular structural configuration and provides a robust analytical basis for the estimation of the probabilistic distribution of selected demands parameters both at the design level and beyond design level seismic input. For the subject structure, the inclusion of foundation sliding in the analysis is found to have

  15. Effects of structural nonlinearity and foundation sliding on probabilistic response of a nuclear structure

    International Nuclear Information System (INIS)

    Hashemi, Alidad; Elkhoraibi, Tarek; Ostadan, Farhang

    2015-01-01

    Highlights: • Probabilistic SSI analysis including structural nonlinearity and sliding are shown. • Analysis is done for a soil and a rock site and probabilistic demands are obtained. • Structural drift ratios and In-structure response spectra are evaluated. • Structural nonlinearity significantly impacts local demands in the structure. • Sliding generally reduces seismic demands and can be accommodated in design. - Abstract: This paper examines the effects of structural nonlinearity and foundation sliding on the results of probabilistic structural analysis of a typical nuclear structure where structural nonlinearity, foundation sliding and soil-structure interaction (SSI) are explicitly included. The evaluation is carried out for a soil and a rock site at 10 4 , 10 5 , and 10 6 year return periods (1E − 4, 1E − 5, and 1E − 6 hazard levels, respectively). The input motions at each considered hazard level are deaggregated into low frequency (LF) and high frequency (HF) motions and a sample size of 30 is used for uncertainty propagation. The statistical distribution of structural responses including story drifts, and in-structure response spectra (ISRS) as well as foundation sliding displacements are examined. The probabilistic implementation of explicit structural nonlinearity and foundation sliding in combination with the SSI effects are demonstrated using nonlinear response history analysis (RHA) of the structure with the foundation motions obtained from elastic SSI analyses, which are applied as input to fixed-base inelastic analyses. This approach quantifies the expected structural nonlinearity and sliding for the particular structural configuration and provides a robust analytical basis for the estimation of the probabilistic distribution of selected demands parameters both at the design level and beyond design level seismic input. For the subject structure, the inclusion of foundation sliding in the analysis is found to have reduced both

  16. Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

    Science.gov (United States)

    Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid

    2015-08-01

    Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm2/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

  17. Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid, E-mail: amsiddiqui@jmi.ac.in [Department of Physics, Jamia Millia Islamia, New Delhi-110025 (India)

    2015-08-28

    Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm{sup 2}/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

  18. Omnidirectional photonic band gap enlarged by one-dimensional ternary unmagnetized plasma photonic crystals based on a new Fibonacci quasiperiodic structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Haifeng [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China); Liu Shaobin [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); State Key Laboratory of Millimeter Waves of Southeast University, Nanjing Jiangsu 210096 (China); Kong Xiangkun; Bian Borui; Dai Yi [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2012-11-15

    In this paper, an omnidirectional photonic band gap realized by one-dimensional ternary unmagnetized plasma photonic crystals based on a new Fibonacci quasiperiodic structure, which is composed of homogeneous unmagnetized plasma and two kinds of isotropic dielectric, is theoretically studied by the transfer matrix method. It has been shown that such an omnidirectional photonic band gap originates from Bragg gap in contrast to zero-n gap or single negative (negative permittivity or negative permeability) gap, and it is insensitive to the incidence angle and the polarization of electromagnetic wave. From the numerical results, the frequency range and central frequency of omnidirectional photonic band gap can be tuned by the thickness and density of the plasma but cease to change with increasing Fibonacci order. The bandwidth of omnidirectional photonic band gap can be notably enlarged. Moreover, the plasma collision frequency has no effect on the bandwidth of omnidirectional photonic band gap. It is shown that such new structure Fibonacci quasiperiodic one-dimensional ternary plasma photonic crystals have a superior feature in the enhancement of frequency range of omnidirectional photonic band gap compared with the conventional ternary and conventional Fibonacci quasiperiodic ternary plasma photonic crystals.

  19. Analysis of cognitive structure of nuclear energy focusing on inhabiting areas, genders, and knowledge

    International Nuclear Information System (INIS)

    Kimura, Hiroshi; Suzuki, Atsuyuki; Furuta, Kazuo

    2003-01-01

    The purpose of this research is to clarify people's cognitive structure of nuclear energy, and to analyze how the cognitive structure varies with inhabiting areas, genders, and knowledge of nuclear energy. For this purpose, we carried out questionnaire survey of perception of nuclear energy in the urban areas and nuclear power plants (NPP) siting areas. After collecting data, we defined 8 categories in terms of respondents' inhabiting areas, genders, and knowledge, and applied factor analysis to each category's data. Consequently, we found 4 cognitive factors of nuclear: 'trust in the authorities', 'utility of nuclear power generation', 'benefit for NPP siting areas', and 'risk perception about nuclear technology', regardless of the respondents' inhabiting areas, genders, and knowledge. In addition, when the respondents assess many perceptions of nuclear energy, respondents living in urban areas tend to regard 'trust in the authorities' as important, while respondents living in NPP siting areas tend to take into consideration of risk perception about nuclear technology'. (author)

  20. Heat transfer enhancement for spent nuclear fuel assembly disposal packages using metallic void fillers: A prevention technique for solidification shrinkage-induced interfacial gaps

    Science.gov (United States)

    Park, Yongsoo; McKrell, Thomas J.; Driscoll, Michael J.

    2017-06-01

    This study considers replacing the externally accessible void spaces inside a disposal package containing a spent nuclear fuel assembly (SNFA) with high heat conducting metal to increase the effective thermal conductivity of the package and simplify the heat transfer mechanism inside the package by reducing it to a conduction dominant problem. The focus of the study is on preventing the gaps adjacent to the walls of the package components, produced by solidification shrinkage of poured liquid metal. We approached the problem by providing a temporary coating layer on the components to avoid direct build-up of thick metal oxides on their surface to promote metallic bonding at the interfaces under a non-inert environment. Laboratory scale experiments without SNFA were performed with Zn coated low carbon steel canisters and Zamak-3 void filler under two different filling temperature conditions - below and above the melting point of Zn (designated BMP and AMP respectively). Gap formation was successfully prevented in both cases while we confirmed an open gap in a control experiment, which used an uncoated canister. Minor growth of Al-Fe intermetallic phases was observed at the canister/filler interface of the sample produced under the BMP condition while their growth was significant and showed irregularly distributed morphology in the sample produced under the AMP condition, which has a potential to mitigate excessive residual stresses caused by shrinkage prevention. A procedure for the full-scale application was specified based on the results.

  1. Energy gaps, electronic structures, and x-ray spectroscopies of finite semiconductor single-walled carbon nanotubes.

    Science.gov (United States)

    Gao, Bin; Jiang, Jun; Wu, ZiYu; Luo, Yi

    2008-02-28

    We report hybrid density functional theory calculations for electronic structures of hydrogen-terminated finite single-walled carbon nanotubes (6,5) and (8,3) up to 100 nm in length. Gap states that are mainly arisen from the hydrogen-terminated edges have been found in (8,3) tubes, but their contributions to the density of states become invisible when the tube is longer than 10 nm. The electronic structures of (6,5) and (8,3) tubes are found to be converged around 20 nm. The calculated band-gap energies of 100 nm long nanotubes are in good agreement with experimental results. The valence band structures of (6,5), (8,3), as well as (5,5) tubes are also investigated by means of ultraviolet photoelectron spectra (UPS), x-ray emission spectroscopy (XES), and the resonant inelastic x-ray scattering (RIXS) spectra theoretically. The UPS, XES and RIXS spectra become converged already at 10 nm. The length-dependent oscillation behavior is found in the RIXS spectra of (5,5) tubes, indicating that the RIXS spectra may be used to determine the size and length of metallic nanotubes. Furthermore, the chiral dependence observed in the simulated RIXS spectra suggests that RIXS spectra could be a useful technique for the determination of chirality of carbon nanotubes.

  2. Ab initio nuclear structure - the large sparse matrix eigenvalue problem

    International Nuclear Information System (INIS)

    Vary, James P; Maris, Pieter; Ng, Esmond; Yang, Chao; Sosonkina, Masha

    2009-01-01

    The structure and reactions of light nuclei represent fundamental and formidable challenges for microscopic theory based on realistic strong interaction potentials. Several ab initio methods have now emerged that provide nearly exact solutions for some nuclear properties. The ab initio no core shell model (NCSM) and the no core full configuration (NCFC) method, frame this quantum many-particle problem as a large sparse matrix eigenvalue problem where one evaluates the Hamiltonian matrix in a basis space consisting of many-fermion Slater determinants and then solves for a set of the lowest eigenvalues and their associated eigenvectors. The resulting eigenvectors are employed to evaluate a set of experimental quantities to test the underlying potential. For fundamental problems of interest, the matrix dimension often exceeds 10 10 and the number of nonzero matrix elements may saturate available storage on present-day leadership class facilities. We survey recent results and advances in solving this large sparse matrix eigenvalue problem. We also outline the challenges that lie ahead for achieving further breakthroughs in fundamental nuclear theory using these ab initio approaches.

  3. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Draayer, Jerry P. [Louisiana State Univ., Baton Rouge, LA (United States)

    2014-09-28

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  4. The energy gap at Z=64 and its implications for the structure of excited states in the A approximately 150

    International Nuclear Information System (INIS)

    Broda, R.

    1980-01-01

    The experimental results are presented indicating the existence of the energy gap in the single particle level sequence at proton number Z=64. Studied experimentally yrast states of the 64 146 Gd 82 closed core nucleus and of the neighbouring nuclei are interpreted within the framework of the spherical shell model. The consideration of the simple shell model multiparticle configurations is suggested to explain the observed frequent appearance of the high-spin isomers in nuclei of the A approximately 150 region. Emphasized is the role of the octupole excitations in the level structures of considered nuclei and some aspects of the coupling of octupole vibrations with valence nucleons are discussed. (author)

  5. Nuclear structure studies. Progress report, [1988--1994

    International Nuclear Information System (INIS)

    Walters, W.B.

    1993-01-01

    In this report, newly initiated work at the FMA is described where the use of double-sided strip detectors for charged particle spectroscopy on nuclides near the proton drip line has been investigated. Half lives for proton emitting nuclides have been determined with improved uncertainties. Several sections report on the results of studies of model parameters in the Z = 50 region for even-even nuclides, for odd-mass nuclides and for odd-odd nuclides. Other studies are reported for nuclear orientation in Br and for structure of Pr-147 which lies in a transition zone between reflection-asymmetric, spherical, and prolate nuclides. And there is a section in which the positions of the single Particle levels in the A = 100 region are discussed

  6. Extending the lifespan of nuclear power plant structures

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.

    1995-01-01

    By the end of this decade, 63 of the 111 commercial nuclear power plants in the United States will be more than 20 years old, with some nearing the end of their 40-year operating license term. Faced with the prospect of having to replace lost generating capacity from other sources and substantial shutdown and decommissioning costs, many utilities are expected to apply to continue the service of their plants past the initial licensing period. In support of such applications, evidence should be provided that the capacity of the safety-related systems and structures to mitigate potential extreme events has not deteriorated unacceptably due to either aging or environmental stressor effects during the previous service history

  7. Towards a Connection Between Nuclear Structure and QCD

    Energy Technology Data Exchange (ETDEWEB)

    Anthony Thomas; Pierre Guichon; Ross Young

    2003-12-01

    As we search for an ever deeper understanding of the structure of hadronic matter one of the most fundamental questions is whether or not one can make a connection to the underlying theory of the strong interaction, QCD. We build on recent advances in the chiral extrapolation problem linking lattice QCD at relatively large, light quark masses to the physical world to estimate the scalar polarizability of the nucleon. The latter plays a key role in modern relativistic mean-field descriptions of nuclei and nuclear matter (such as QMC) and, in particular, leads to a very natural saturation mechanism. We demonstrate that the value of the scalar polarizability extracted from the lattice data is consistent with that needed for a successful description of nuclei within the framework of QMC. In a very real sense this is the first hint of a direct connection between QCD and the properties of finite nuclei.

  8. Seismic capacities of existing nuclear power plant structures

    International Nuclear Information System (INIS)

    Wesley, D.A.; Hashimoto, P.S.; Narver, R.B.

    1983-01-01

    The paper presents a discussion of the more important conservatisms and some of the results obtained when this methodology has been applied to various nuclear plants. Results are shown for both BWR and PWR plants, on both rock and soil sites, and for plants and soil sites, and for plants that were designed in the late 1960s to plants that have yet to load fuel. Safe shutdown earthquake design levels of 0.1 g to 0.25 g were used for these plants. Overall median structural factors of safety for the lowest significant seismic failure capacity at each plant ranged from 3.5 to 8.5. The lowest containment-related failure capacity at each plant ranged from 4.6 to 31. The types of failure corresponding to each safety factor are also tabulated. (orig./HP)

  9. Vessel supporting structure for liquid metal cooled nuclear reactors

    International Nuclear Information System (INIS)

    Mahe, Armel; Jullien, Georges

    1974-01-01

    The supporting structure described is for a liquid metal cooled nuclear reactor, the vessel being of the type suspended to the end slab of the reactor. It includes a ring connected at one of its two ends to a single shell and at the other end to two shells. One of these three shells connected to the lower end of the ring forms the upper part of the vessel to be supported. The two other shells are embedded in two sperate parts of the slab. The ring and shell assembly is housed in an annular space provided in the end slab and separating it into two parts, namely a central part and a peripheral part [fr

  10. Vibrational Order, Structural Properties, and Optical Gap of ZnO Nanostructures Sintered through Thermal Decomposition

    Directory of Open Access Journals (Sweden)

    Alejandra Londono-Calderon

    2014-01-01

    Full Text Available The sintering of different ZnO nanostructures by the thermal decomposition of zinc acetate is reported. Morphological changes from nanorods to nanoparticles are exhibited with the increase of the decomposition temperature from 300 to 500°C. The material showed a loss in the crystalline order with the increase in the temperature, which is correlated to the loss of oxygen due to the low heating rate used. Nanoparticles have a greater vibrational freedom than nanorods which is demonstrated in the rise of the main Raman mode E 2(high during the transformation. The energy band gap of the nanostructured material is lower than the ZnO bulk material and decreases with the rise in the temperature.

  11. Vulnerability of nuclear power plant structures to large external fires

    International Nuclear Information System (INIS)

    Bennett, D.E.

    1983-08-01

    This report examines the inherent vulnerability of nuclear power plant structures to the thermal environments arising from large, external fires. The inherent vulnerability is the capacity of the concrete safety-related structures to absorb thermal loads without exceeding the appropriate thermal and structural design criteria. The potential sources of these thermal environments are large, offsite fires arising from accidents involving the transportation or storage of large quantities of flammable gases or liquids. A realistic thermal response analysis of a concrete panel was performed using three limiting criteria: temperature at the first rebar location, erosion and ablation of the front (exterior) surface due to high heat fluxes, and temperature at the back (interior) surface. The results of this analysis yield a relationship between incident heat flux and the maximum allowable exposure duration. Example calculations for the break of a 0.91 m (3') diameter high-pressure natural gas pipeline and a 1 m 2 hole in a 2-1/2 million gallon gasoline tank show that the resulting fires do not pose a significant hazard for ranges of 500 m or greater

  12. Development of an automated fracture. Assessment system for nuclear structures

    International Nuclear Information System (INIS)

    Mikkola, T.P.J.; Raiko, H.

    1992-01-01

    A program system for fracture assessment of nuclear power plant structures has been developed. The system consists of an easy-to-use program for engineering analysis and an automated finite element (FE) program system for more accurate analysis with solid three-dimensional (3D) models. The VTTSIF (SIF stress intensity factor) program for engineering fracture assessment applies either the weight function method or superposition method in calculating the stress intensity factor, and the fatigue crack growth analysis is based on the Paris equation. The structural geometry cases of the VTTSIF program are organized in an extendable subroutine database. The generation of a 3D FE model of a cracked structure is automated by the ACR program (automatic finite element model generation for part through cracks). The FE analyses are created with generally accepted commercial programs, and the virtual crack extension method (VCE) is used for fracture parameter evaluation by the VTTVIRT postprocessor program (program for J-integral evaluation using virtual crack extension method). The several test cases have demonstrated that the accuracy of the present system is satisfactory for practical applications. (author)

  13. Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure

    Directory of Open Access Journals (Sweden)

    Min Hu

    2013-02-01

    Full Text Available We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental accelerating mode and dipole modes are excited by passing an 18 MeV electron beam through a seven-cell traveling-wave PBG structure. The characteristics of the longitudinal and transverse wakefields, wake potential spectrum, dipole mode distribution, and their quality factors are calculated and analyzed theoretically. Unlike in conventional disk-loaded waveguide (DLW structures, three dipole modes (TM_{11}-like, TM_{12}-like, and TM_{13}-like are excited in the PBG structure with comparable initial amplitudes. These modes are separated by less than 4 GHz in frequency and are damped quickly due to low radiative Q factors. Simulations verify that a PBG structure provides wakefield damping relative to a DLW structure. Simulations were done with both single-bunch excitation to determine the frequency spectrum of the wakefields and multibunch excitation to compare to wakefield measurements taken at MIT using a 17 GHz bunch train. These simulation results will guide the design of next-generation high-gradient accelerator PBG structures.

  14. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Technical progress report, November 1, 1978-October 31, 1979. [Summaries of research activities at Washington Univ

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1979-01-01

    Experimental research on nuclear structure and reactions both published and in progress is summarized. Included are fusion reactions, strongly damped heavy ion collisions, and nuclear structure at high angular momentum. A list of publications is included. (JFP)

  15. Nonlinear seismic soil-structure interaction analysis of nuclear power plant structures

    International Nuclear Information System (INIS)

    Khanna, J.K.; Setlur, A.V.; Pathak, D.V.

    1977-01-01

    The heterogeneous and nonlinear soil medium and the detailed three-dimensional structure are synthesized to determine the seismic response to soil-structure systems. The approach is particularly attractive in a design office environment since it: a) leads to interactive motion at the soil-structure interface; b) uses existing public domain programs such as SAPIV, LUSH and FLUSH with marginal modifications; and c) meets current regulatory requirements for soil-structure interaction analysis. Past methods differ from each other depending on the approach adopted for soil and structure representations and procedures for solving the governing differential equations. Advantages and limitations of these methods are reviewed. In the current approach, the three-dimensional structure is represented by the dynamic characteristics of its fixed base condition. This representation is ideal when structures are designed to be within elastic range. An important criterion is the design of the nuclear power plant structures. Model damping coefficients are varied to reflect the damping properties of different structural component materials. The detailed structural model is systematically reduced to reflect important dynamic behavior with simultaneous storing of intermediate information for retrieval of detailed structural response. Validity of the approach has been established with simple numerical experiments. (Auth.)

  16. Influence of nuclear fuel cycle duration and reprocessing losses level on the nuclear power system structure

    International Nuclear Information System (INIS)

    Alekseev, P. N.; Dudnikov, A. A.; Subbotin, S. A.

    2004-01-01

    It is shown that three-component Nuclear Power (NP) system consisting of thermal reactors (TR), fast reactors (FR) and molten salt reactors-burners (MSR) can operate in mode when actinides in system are not stored up proportionally to energy generated but are practically at steady level proportionally to system power. In the paper there was considered the influence of nuclear fuel cycle (NFC) duration and level of irretrievable reprocessing losses on NP structure and fuel consumption efficiency. U-Pu and U-Th variants of NP systems were considered with various levels of irretrievable reprocessing losses for all actinides - 0%, 0.1% and 1%, and various duration of cooling and reprocessing time of TR fuel cycle (TRR time) - 3 years, 6 years, 9 years, 20 years. Steady state calculations were performed for three-component NP systems and there were obtained steady state amounts and radioactivity of actinides for main components of NFC closed by actinides. Also, there were obtained rates and radioactivity of accumulation of actinide irretrievable reprocessing losses. (authors)

  17. An observation of direct-gap electroluminescence in GaAs structures with Ge quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Aleshkin, V. Ya. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Dikareva, N. V. [Lobachevsky State University of Nizhny Novgorod, Physical Technical Research Institute (Russian Federation); Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Lobachevsky State University of Nizhny Novgorod, Physical Technical Research Institute (Russian Federation); Kudryavtsev, K. E. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Nekorkin, S. M. [Lobachevsky State University of Nizhny Novgorod, Physical Technical Research Institute (Russian Federation)

    2015-02-15

    A light-emitting diode structure based on GaAs with eight narrow Ge quantum wells is grown by laser sputtering. An electroluminescence line polarized predominately in the plane parallel to the constituent layers of the structure is revealed. The line corresponds to the direct optical transitions in momentum space in the Ge quantum wells.

  18. Structural modification and band gap engineering of sol–gel dip

    Indian Academy of Sciences (India)

    In the present study, we investigated the effect of vacuum annealing on the structural and optical properties of sol–gel dip-coated thin films of Zn 0.75 Mg 0.25 O alloy. XRD studies revealed that all these films werepolycrystalline with hexagonal wurtzite structure and there was no trace of additional phases other than ZnO.

  19. Analysis of photonic band-gap (PBG) structures using the FDTD method

    DEFF Research Database (Denmark)

    Tong, M.S.; Cheng, M.; Lu, Y.L.

    2004-01-01

    behavior of these structures, and the computed results generally match well with ones published in the literature. It is also found that the FDTD method is a robust, versatile, and powerful numerical technique to perform such numerical studies. The proposed PBG filter structures may be applied in microwave...

  20. Structural modification and band gap engineering of sol–gel dip ...

    Indian Academy of Sciences (India)

    In the present study, we investigated the effect of vacuum annealing on the structural and optical properties of sol–gel dip-coated thin films of Zn 0.75 Mg 0.25 O alloy. XRD studies revealed that all these films werepolycrystalline with hexagonal wurtzite structure and there was no trace of additional phases other than ZnO.

  1. Effect of sputtering power on the structure and optical band gap of SiC thin films

    Science.gov (United States)

    Cheng, Yong; Huang, Xiaozhong; Du, Zuojuan; Xiao, Jianrong

    2017-11-01

    Amorphous SiC (a-SiC) thin films with a quartz plate as the substrate were prepared under different radio frequency (RF) powers through RF magnetron sputtering. Films structures were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD) and Raman spectrum. The absorption spectra of the thin films were acquired with UV-visible spectroscopy. Results showed that thin films prepared under different RF powers have different structures. With the increase in power, the maximum peak height, mean roughness, and mean square roughness increase initially and then decrease. The thin films are mainly composed of SiC and SiO2 bonds and contain abundant C. ID/IG increases as power increases. The UV-visible light absorption spectra confirmed that the thin films have strong UV absorption capacity but low absorption capacity in the infrared region. The optical band gap of the thin films ranges between 1.29 and 1.80 eV. With the increase in RF power, the sp3/sp2C hybrid bond in the thin films increases, resulting in a reduction of the optical band gap.

  2. The increasing unemployment gap between the low and high educated in West Germany. Structural or cyclical crowding-out?

    Science.gov (United States)

    Klein, Markus

    2015-03-01

    This paper addresses trends in education-specific unemployment risks at labor market entry in West Germany from the mid-1970s to the present. In line with previous research it shows that vocationally qualified school-leavers have relatively lower unemployment risks than school-leavers with general education. Over time, the gap in unemployment risks between the low-educated and medium- and highly educated labor market entrants substantially widened for both sexes. The literature identifies two different mechanisms for this trend: structural or cyclical crowding out. While in the former scenario low-educated become increasingly unemployed due to an oversupply of tertiary graduates and displacement from above, in the latter their relative unemployment risk varies with the business cycle. The results provide evidence for cyclical rather than structural crowding-out in West Germany. Since macroeconomic conditions became generally worse over time, this strongly explains the widening unemployment gap between the low-educated and all other education groups. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Composition and structure of natural organic matter through advanced nuclear magnetic resonance techniques

    Directory of Open Access Journals (Sweden)

    Dainan Zhang

    2017-02-01

    Full Text Available Abstract Natural organic matter (NOM plays important roles in biological, chemical, and physical processes within the terrestrial and aquatic ecosystem. Despite its importance, a clear and exhaustive knowledge on NOM chemistry still lacks. Aiming to prove that advanced solid-state 13C nuclear magnetic resonance (NMR techniques may contribute to fill such a gap, in this paper we reported relevant examples of its applicability to NOM components, such as biomass, deposition material, sediments, and kerogen samples. It is found that nonhydrolyzable organic carbons (NHC, chars, and polymethylene carbons are important in the investigated samples. The structure of each of the NHC fractions is similar to that of kerogens, highlighting the importance of selective preservation of NOM to the kerogen origin in the investigated aquatic ecosystems. Moreover, during the artificial maturation experiments of kerogen, the chemical and structural characteristics such as protonated aromatic, nonprotonated carbons, and aromatic cluster size play important roles in the origin and variation of nanoporosity during kerogen maturation. Graphical abstract NMR parameters of thermally stimulated kerogens

  4. The effect of cilostamide on gap junction communication dynamics, chromatin remodeling, and competence acquisition in pig oocytes following parthenogenetic activation and nuclear transfer.

    Science.gov (United States)

    Dieci, Cecilia; Lodde, Valentina; Franciosi, Federica; Lagutina, Irina; Tessaro, Irene; Modina, Silvia C; Albertini, David F; Lazzari, Giovanna; Galli, Cesare; Luciano, Alberto M

    2013-09-01

    In the pig, the efficiency of in vitro embryo production and somatic cell nuclear transfer (SCNT) procedures remains limited. It has been suggested that prematuration treatments (pre-IVM) based on the prolongation of a patent, bidirectional crosstalk between the oocyte and the cumulus cells through gap junction mediate communication (GJC), with the maintenance of a proper level of cAMP, could improve the developmental capability of oocytes. The aim of this study was to assess: 1) dose-dependent effects of cilostamide on nuclear maturation kinetics, 2) the relationship between treatments on GJC functionality and large-scale chromatin configuration changes, and 3) the impact of treatments on developmental competence acquisition after parthenogenetic activation (PA) and SCNT. Accordingly, cumulus-oocyte complexes were collected from 3- to 6-mm antral follicles and cultured for 24 h in defined culture medium with or without 1 μM cilostamide. GJC functionality was assessed by Lucifer yellow microinjection, while chromatin configuration was evaluated by fluorescence microscopy after nuclear staining. Cilostamide administration sustained functional coupling for up to 24 h of culture and delayed meiotic resumption, as only 25.6% of cilostamide-treated oocytes reached the pro-metaphase I stage compared to the control (69.7%; P < 0.05). Moreover, progressive chromatin condensation was delayed before meiotic resumption based upon G2/M biomarker phosphoprotein epitope acquisition using immunolocalization. Importantly, cilostamide treatment under these conditions improved oocyte developmental competence, as reflected in higher blastocyst quality after both parthenogenetic activation and SCNT.

  5. Discrimination of the wall effect in a thin counter with micro-gap structure for neutron position sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sakae, Takeji; Manabe, Tohru; Kitamura, Yasunori; Nohtomi, Akihiro [Kyushu Univ., Fukuoka (Japan); Sakamoto, Sigeyasu

    1996-07-01

    Simulation by the Monte Carlo method is applied to estimate the wall effect in a thermal neutron counter having a new function for discriminating the effect. The counter is designed to have paralleled electrodes with micro-gap structure. A resistive anode is used for position sensing on the center of a set of the three electrode. The structure can be made by simple arrangement of anode and cathode wires on an insulator plane. The calculation shows discrimination of the wall effect can be achieved by coincident counting of two or three elements included in the counter. By using the coincident counting, the thickness of the neutron counter can be made into 1 mm with the information of the total energy created in the neutron detection. (author)

  6. Wilson loops from multicentre and rotating branes, mass gaps and phase structure in gauge theories

    CERN Document Server

    Brandhuber, A.

    1999-01-01

    Within the AdS/CFT correspondence we use multicentre D3-brane metrics to investigate Wilson loops and compute the associated heavy quark-antiquark potentials for the strongly coupled SU(N) super-Yang-Mills gauge theory, when the gauge symmetry is broken by the expectation values of the scalar fields. For the case of a uniform distribution of D3-branes over a disc, we find that there exists a maximum separation beyond which there is no force between the quark and the antiquark, i.e. the screening is complete. We associate this phenomenon with the possible existence of a mass gap in the strongly coupled gauge theory. In the finite-temperature case, when the corresponding supergravity solution is a rotating D3-brane solution, there is a class of potentials interpolating between a Coulombic and a confining behaviour. However, above a certain critical value of the mass parameter, the potentials exhibit a behaviour characteristic of statistical systems undergoing phase transitions. The physical path preserves the c...

  7. The horizon of nuclear structure studies and its roots in the country

    International Nuclear Information System (INIS)

    Warke, C.S.

    1995-01-01

    The current aims and goals of nuclear spectroscopic studies are brought out. The concepts and physical pictures developed from the experimental results of high spin nuclear spectroscopy are discussed. The importance of nuclear structure in sub-barrier fusion reaction is presented. A sketch of recent developments in giant resonance studies is given. The structure and nuclear matter problems of interest in astro-nuclear physics are covered. References are cited to the relevant contributions made to workshop. The open problems that will attract attention and efforts are speculated. (author)

  8. Research resource: novel structural insights bridge gaps in glycoprotein hormone receptor analyses.

    Science.gov (United States)

    Kreuchwig, Annika; Kleinau, Gunnar; Krause, Gerd

    2013-08-01

    The first version of a glycoprotein hormone receptor (GPHR) information resource was designed to link functional with structural GPHR information, in order to support sequence-structure-function analysis of the LH, FSH, and TSH receptors (http://ssfa-gphr.de). However, structural information on a binding- and signaling-sensitive extracellular fragment (∼100 residues), the hinge region, had been lacking. A new FSHR crystal structure of the hormone-bound extracellular domain has recently been solved. The structure comprises the leucine-rich repeat domain and most parts of the hinge region. We have not only integrated the new FSHR/FSH structure and the derived homology models of TSHR/TSH, LHCGR/CG, and LHCGR/LH into our web-based information resource, but have additionally provided novel tools to analyze the advanced structural features, with the common characteristics and distinctions between GPHRs, in a more precise manner. The hinge region with its second hormone-binding site allows us to assign functional data to the new structural features between hormone and receptor, such as binding details of a sulfated tyrosine (conserved throughout the GPHRs) extending into a pocket of the hormone. We have also implemented a protein interface analysis tool that enables the identification and visualization of extracellular contact points between interaction partners. This provides a starting point for comparing the binding patterns of GPHRs. Together with the mutagenesis data stored in the database, this will help to decipher the essential residues for ligand recognition and the molecular mechanisms of signal transduction, extending from the extracellular hormone-binding site toward the intracellular G protein-binding sites.

  9. Assessment of soil/structure interaction analysis procedures for nuclear power plant structures

    International Nuclear Information System (INIS)

    Young, G.A.; Wei, B.C.

    1977-01-01

    The paper presents an assessment of two state-of-the-art soil/structure interaction analysis procedures that are frequently used to provide seismic analyses of nuclear power plant structures. The advantages of large three-dimensional, elastic, discrete mass models and two-dimensional finite element models are compared. The discrete mass models can provide three-dimensional response capability with economical computer costs but only fair soil/structure interaction representation. The two-dimensional finite element models provide good soil/structure interaction representation, but cannot provide out-of-plane response. Three-dimensional finite element models would provide the most informative and complete analyses. For this model, computer costs would be much greater, but modeling costs would be approximately the same as those required for three-dimensional discrete mass models

  10. Nuclear containment structure subjected to commercial and fighter aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Sadique, M.R., E-mail: rehan.sadique@gmail.com; Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in; Bhargava, P., E-mail: bhpdpfce@iitr.ernet.in

    2013-07-15

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment.

  11. Nuclear containment structure subjected to commercial and fighter aircraft crash

    International Nuclear Information System (INIS)

    Sadique, M.R.; Iqbal, M.A.; Bhargava, P.

    2013-01-01

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment

  12. Theory of nuclear structure and reactions. Annual technical progress report, April 1, 1984-March 31, 1985

    International Nuclear Information System (INIS)

    Macfarlane, M.H.; Serot, B.D.

    1985-01-01

    In the period covered by this report, work focused on five main areas: (1) relativistic effects in intermediate-energy nuclear reactions; (2) the role of quarks and gluons in nuclear physics; (3) quantum hadrodynamics and relativistic nuclear mean-field theory; (4) structure and reaction effects in intermediate-energy nuclear reactions; and (5) weak and electromagnetic interactions in nuclei. Results and publications in these areas are summarized. Publications are listed

  13. Co-ordination of the international network of nuclear structure and decay data evaluators

    International Nuclear Information System (INIS)

    Schmidt, J.J.

    1988-10-01

    The IAEA Nuclear Data Section convened the eighth meeting of the international nuclear structure and decay data network at Ghent, Belgium, 16-20 May 1988. The meeting was attended by 21 scientists from 12 Member States and three international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. This document contains a summary of the meeting, the proceedings of the meeting and in appendices status reports of activities in nuclear structure and decay data from the participating centers. Refs and tabs

  14. Co-ordination of the international network of nuclear structure and decay data evaluation

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1991-11-01

    The IAEA Nuclear Data Section convened the ninth meeting of the international nuclear structure and decay data network at Kuwait, 10-14 March 1990. The meeting was attended by 19 scientists from 9 Member States and two international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. The document contains a summary and the proceedings of the meeting, and in annexes, status reports of activities in nuclear structure and decay data from the participating centers. A separate abstract was prepared for one of the scientific lectures related to the topics of the meeting which is reproduced in full length. Refs, figs and tabs

  15. In Few Words: Linguistic Gap but Adequate Narrative Structure in Preschool Bilingual Children

    Science.gov (United States)

    Bonifacci, Paola; Barbieri, Margherita; Tomassini, Marta; Roch, Maja

    2018-01-01

    The aim of this study was to compare linguistic and narrative skills of monolingual and bilingual preschoolers and to estimate linguistic predictors of the macro-structural level of narratives. A battery of linguistic measures in Italian was administered to sixty-four Monolinguals and sixty-four Early Bilinguals; it included Vocabulary,…

  16. The effect of Y3+substitution on the structural, optical band-gap, and magnetic properties of cobalt ferrite nanoparticles.

    Science.gov (United States)

    Alves, T E P; Pessoni, H V S; Franco, A

    2017-06-28

    In this study we investigated the structural, optical band-gap, and magnetic properties of CoY x Fe 2-x O 4 (0 ≤ x ≤ 0.04) nanoparticles (NPs) synthesized using a combustion reaction method without the need for subsequent heat treatment or the calcing process. The particle size measured from X-ray diffraction (XRD) patterns and transmission electron microscope (TEM) images confirms the nanostructural character in the range of 16-36 nm. The optical band-gap (E g ) values increase with the Y 3+ ion (x) concentration being 3.30 and 3.58 eV for x = 0 and x = 0.04, respectively. The presence of yttrium in the cobalt ferrite (Y-doped cobalt ferrite) structure affects the magnetic properties. For instance, the saturation magnetization, M s and remanent magnetization, M r , decrease from 69 emu g -1 to 33 and 28 to 12 emu g -1 for x = 0 and x = 0.04, respectively. On the other hand the coercivity, H c , increases from 1100 to 1900 Oe for x = 0 and x = 0.04 at room temperature. Also we found that M s , M r , and H c decreased with increasing temperature up to 773 K. The cubic magnetocrystalline constant, K 1 , determined by using the "law of approach" (LA) to saturation decreases with Y 3+ ion concentration and temperature. K 1 values for x = 0 (x = 0.04) were 3.3 × 10 6 erg cm -3 (2.0 × 10 6 erg cm -3 ) and 0.4 × 10 6 erg cm -3 (0.3 × 10 6 erg cm -3 ) at 300 K and 773 K, respectively. The results were discussed in terms of inter-particle interactions induced by thermal fluctuations, and Co 2+ ion distribution over tetrahedral A-sites and octahedral B-sites of the spinel structure due to Y 3+ ion substitution.

  17. Proceedings of the Conference on Structural Analysis and Design of Nuclear Power Plants. v. 2

    International Nuclear Information System (INIS)

    1984-01-01

    It's presented the discussion of recents research results and developments related to applications of structural mechanics and seismology to mechanical structures and to nuclear facility sites. (E.G.) [pt

  18. Electronic Structures, Bonding Configurations, and Band-Gap-Opening Properties of Graphene Binding with Low-Concentration Fluorine.

    Science.gov (United States)

    Duan, Yuhua; Stinespring, Charter D; Chorpening, Benjamin

    2015-10-01

    To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2 H and graphene have zero band gaps. When fluorine bonds to a carbon atom, the carbon atom is pulled slightly above the graphene plane, creating what is referred to as a CF defect. The lowest-binding energy state is found to correspond to two CF defects on nearest neighbor sites, with one fluorine above the carbon plane and the other below the plane. Overall this has the effect of buckling the graphene. The results further show that the addition of fluorine to graphene leads to the formation of an energy band (BF) near the Fermi level, contributed mainly from the 2p orbitals of fluorine with a small contribution from the p orbitals of the carbon. Among the 11 binding configurations studied, our results show that only in two cases does the BF serve as a conduction band and open a band gap of 0.37 eV and 0.24 eV respectively. The binding energy decreases with decreasing fluorine concentration due to the interaction between neighboring fluorine atoms. The obtained results are useful for sensor development and nanoelectronics.

  19. Universal heat conduction and nodal gap structure of the heavy-fermion superconductor CeIrIn5

    Science.gov (United States)

    Shakeripour, H.; Tanatar, M. A.; Petrovic, C.; Taillefer, Louis

    2010-11-01

    The effect of impurity scattering on the thermal conductivity κ of the heavy-fermion superconductor CeIrIn5 was studied for a current parallel (J∥c) and perpendicular (J∥a) to the tetragonal c axis. For J∥a , adding La impurities does not change the residual linear term κ0a/T , showing that heat conduction in the basal plane is universal, compelling evidence that the superconducting gap vanishes along a symmetry-imposed line. By contrast, for J∥c , La impurities greatly enhance the residual linear term κ0c/T . This is strong evidence that the line of nodes lies within the basal plane, a gap structure which is inconsistent with the d -wave symmetry proposed for the isostructural superconductor CeCoIn5 . Different symmetries in the two materials could explain why the phase diagram of this heavy-fermion family consists of two separate superconducting domes. We also compare our data on CeIrIn5 to corresponding data on the heavy-fermion superconductor UPt3 , where no universal conduction is observed.

  20. Structural integrity for DEMO: An opportunity to close the gap from materials science to engineering needs

    Energy Technology Data Exchange (ETDEWEB)

    Porton, M., E-mail: michael.porton@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Wynne, B.P. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); University of Sheffield, Sheffield, South Yorkshire S10 2TN (United Kingdom); Bamber, R.; Hardie, C.D.; Kalsey, M. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2016-11-01

    Highlights: • Key shortfalls in the current approaches to verification of structural integrity are outlined. • Case studies for high integrity applications in other demanding environments are examined. • Relevant lessons are drawn from fission and space for the design stage and through service life. • Future efforts are suggested to align materials and engineering for DEMO structural integrity. - Abstract: It is clear that fusion demonstration devices offer unique challenges due to the myriad, interacting material degradation effects and the numerous, conflicting requirements that must be addressed in order for in-vessel components to deliver satisfactory performance over the required lifetime. The link between mechanical engineering and materials science is pivotal to assure the timely realisation and exploitation of successful fusion power. A key aspect of this link is the verification of structural integrity, achieved at the design stage via structural design criteria against which designs are judged to be sufficiently resilient (or not) to failure, for a given set of loading conditions and desired lifetime. As various demonstration power plant designs progress through their current conceptual design phases, this paper seeks to highlight key shortfalls in this vital link between engineering needs and materials science, offering a perspective on where future attention can be prioritised to maximise impact. Firstly, issues in applying existing structural design criteria to demonstration power plant designs are identified. Whilst fusion offers particular challenges, there are significant insights to be gained from attempts to address such issues for high performance, high integrity applications in other demanding environments. Therefore case studies from beyond fusion are discussed. These offer examples where similar shortfalls have been successfully addressed, via approaches at the design stage and through service lifetime in order to deliver significant

  1. Coordination of the international network of nuclear structure and decay data evaluators

    International Nuclear Information System (INIS)

    Lorenz, A.

    1984-09-01

    This meeting of the International NSDD (Nuclear Structure and Decay Data) Network dealt with problems related to both the coordination of the NSDD network of centres and groups and to physics questions related to the evaluation of NSDD. The status of the mass-chain and nuclear structure data is reviewed and the planned activities are presented

  2. Photonic band gap effect and structural color from silver nanoparticle gelatin emulsion.

    Science.gov (United States)

    Kok, Mang Hin; Ma, Rui; Lee, Jeffrey Chi Wai; Tam, Wing Yim; Chan, C T; Sheng, Ping; Cheah, Kok Wai

    2005-10-01

    We have fabricated planar structures of silver nanoparticles in monochromatic gelatin emulsion with a continuous spacing ranging from 0.15-0.40 micron using a two-beam interference of a single laser source. Our planar holograms display a colorful "rainbow" pattern and photonic bandgaps covering the visible and IR ranges. We model the planar silver nanoparticle-gelatin composite system using an effective medium approach and good agreement is obtained between theory and experiment.

  3. Quarkeosynthesis: a correct science of nuclear structure, forces and energy

    Science.gov (United States)

    Webb, William

    2010-11-01

    Quarkeosynthesis owes its success to the simple postulation that during synthesis of nuclei it's the Quarks that do the combining: not whole nucleons. String-like quarks combine to build more massive rope-like Quarks: hence the title Quarkeosynthesis. Nuclei are thus all made of three loops of flexible string-like material that rotate with a circular ring shape. All nuclei have two positive charged Quarks and a single negative charged Quark. Electrostatic attraction and repulsion bind each threesome in its structure. There are no special nuclear strong or weak forces and no gluon material or bosons. Quarks rotate at high speeds so a portion of their mass is relativistic. Intrinsic mass of all small mass nuclei neighbors 72.5%. Quarks have a radial wave motion. Waves move with the same speed as the rotational speed of the Quark itself so Quarks can obey the Einstein mass-energy equation. Wave energy is an integral part of a nucleus' total mass-energy and determines its binding energy. Quarkeosynthesis correctly determines, without exception, the beta decay and stability of the 65 least massive nuclei. A primer on Quarkeo-synthesis is available from wbwebb@rconnect.com.

  4. Introduction to structural failure modes for nuclear power facilities

    International Nuclear Information System (INIS)

    Reed, J.W.; Gurbuz, O.

    1993-01-01

    This introduction provides a background of the evaluation methods for earthquakes larger than design basis. Seismic probabilistic risk assessment (SPRA) and seismic margin assessment (SMA) methods are introduced to the reader. The basic parameters used to define seismic capacity for each method are explained. The objectives of both evaluation methods and how they can be used to evaluate the adequacy of a seismic design are discussed. General issues related to computing seismic capacity are reviewed relative to SPRA and SMA. Four companion papers presented in the journal following this introduction discuss the types of information (i.e., dynamic tests, earthquake experience, and analytical data) that are used to determine the real capacity of structures and equipment in nuclear power plants to resist earthquakes. The motivation for discussing these three types of information is presented as an introduction to these papers that following in this journal edition. The purpose of the present paper is to lay the groundwork and provide motivation for these papers

  5. Nuclear structure and reaction studies at medium energies

    International Nuclear Information System (INIS)

    Hoffmann, G.W.; Ray, R.L.

    1990-10-01

    This document constitutes the (1988--1991) technical progress report for the ongoing medium energy physics research program supported by the US Department of Energy through special Research Grant FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF), the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL), and at the Fermi National Accelerator Laboratory (FNAL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics;(2) provide unique, first-of-a-kind ''exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics

  6. Seismicity Pattern and Fault Structure in the Central Himalaya Seismic Gap Using Precise Earthquake Hypocenters and their Source Parameters

    Science.gov (United States)

    Mendoza, M.; Ghosh, A.; Rai, S. S.

    2017-12-01

    The devastation brought on by the Mw 7.8 Gorkha earthquake in Nepal on 25 April 2015, reconditioned people to the high earthquake risk along the Himalayan arc. It is therefore imperative to learn from the Gorkha earthquake, and gain a better understanding of the state of stress in this fault regime, in order to identify areas that could produce the next devastating earthquake. Here, we focus on what is known as the "central Himalaya seismic gap". It is located in Uttarakhand, India, west of Nepal, where a large (> Mw 7.0) earthquake has not occurred for over the past 200 years [Rajendran, C.P., & Rajendran, K., 2005]. This 500 - 800 km long along-strike seismic gap has been poorly studied, mainly due to the lack of modern and dense instrumentation. It is especially concerning since it surrounds densely populated cities, such as New Delhi. In this study, we analyze a rich seismic dataset from a dense network consisting of 50 broadband stations, that operated between 2005 and 2012. We use the STA/LTA filter technique to detect earthquake phases, and the latest tools contributed to the Antelope software environment, to develop a large and robust earthquake catalog containing thousands of precise hypocentral locations, magnitudes, and focal mechanisms. By refining those locations in HypoDD [Waldhauser & Ellsworth, 2000] to form a tighter cluster of events using relative relocation, we can potentially illustrate fault structures in this region with high resolution. Additionally, using ZMAP [Weimer, S., 2001], we perform a variety of statistical analyses to understand the variability and nature of seismicity occurring in the region. Generating a large and consistent earthquake catalog not only brings to light the physical processes controlling the earthquake cycle in an Himalayan seismogenic zone, it also illustrates how stresses are building up along the décollment and the faults that stem from it. With this new catalog, we aim to reveal fault structure, study

  7. Propagation of long-range surface plasmon polaritons in photonic band gap structures

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Søndergaard, Thomas; Nikolajsen, Thomas

    2005-01-01

    We study the interaction of long-range surface plasmon polaritons (LR-SPPs), excited at telecommunication wavelengths, with photonic crystals (PCs) formed by periodic arrays of gold bumps that are arranged in a triangular lattice and placed symmetrically on both sides of a thin gold fil embedded...... in polymer. Radiation is delivered to and from the PC structures with the help of LR-SPP guides that consist of 8 mm wide and 15 nm thick gold stripes attached to wide film sections (of the same thickness) covered with bumps (diameter ~300 nm, height up to 150 nm on each side of the film). We investigate......, is rather weak, so that the photonic bandgap effect might be expected to take place only for some particular propagation directions. Preliminary experiments on LR-SPP bending and splitting at large angles are reported, and further research directions are discussed....

  8. Aging management of safety-related concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Arndt, E.G.

    1990-01-01

    The Structural Aging Program has the overall objective of providing the US Nuclear Regulatory Commission with an improved basis for evaluating nuclear power plants for continued service. In meeting this objective, a materials property data base is being developed as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, studies are well under way to review and assess inservice inspection techniques for concrete structures and to develop a methodology which can be used for performing current as well as reliability-based future conditions assessments of these structures. 16 refs., 2 tabs

  9. Design, fabrication and erection of steel structures important to safety of nuclear facilities

    International Nuclear Information System (INIS)

    2001-10-01

    Civil engineering structures in nuclear installations form an important feature having implications to safety performance of these installations. The objective and minimum requirements for the design of civil engineering buildings/structures to be fulfilled to provide adequate assurance for safety of nuclear installations in India (such as pressurised heavy water reactor and related systems) are specified in the Safety Standard for Civil Engineering Structures Important to Safety of Nuclear Facilities. This standard is written by AERB to specify guidelines for implementation of the above civil engineering safety standard in the design, fabrication and erection of steel structures important to safety

  10. Frontiers of Nuclear Structure Physics - Proceedings of the International Symposium held in Honor of Akito Arima

    Science.gov (United States)

    Ishihara, M.; Otsuka, T.; Mizusaki, T.; Yazaki, K.

    1996-01-01

    The Table of Contents for the full book PDF is as follows: * Preface * Aspects of the structure of light nuclei * A frontier of shell model calculation: large-scale calculation with G-matrix interaction in middle pf-shell * Realistic large-basis shell-model calculation in the low-mass tin isotopes * Isospin symmetry breaking in light nuclei * The role of pairing in nuclear collective motion * Universal correlations of collective observables: empirical phenomenology and model interpretations * Interacting Boson Model for O(6) nuclei * Multiple Q-phonon modes in even barium nuclei * Two-phonon γ-vibrational states in deformed nuclei * Scattering of GeV electrons by nuclei * Nuclear structure experiments at CEBAF * Correlations and relativistic features in nuclear structure * Collective string-like model of baryons * Hadron-nucleon scattering lengths in QCD sum rules * Atomic yrast brands of metastable amiprotonic helium atomcules * Loosely coupling few-body systems * Nuclear spin responses in astroparticle physics * Towards extremes of nuclear states with radioactive beams * Strangeness Nuclear Physics: experimental tests of quark-based pictures * Deep hole states and hypernuclei * Simple two-body effective-interaction matrix elements and realistic microscopic nuclear-structure calculations * Signature and parity splitting in rotational bands: double minimal potential model * Search for mixed-symmetry states in O(6) nuclei * From the shell model to the interacting boson model * Optimal pair description of nuclear motions in a degenerate orbit * Some current topics in nuclear structure at drip lines * Halo structure of light neutron-rich nuclei * Nucleosynthesis in explosive hydrogen burning process * Nuclear astrophysics with secondary (radioactive) beams * Magnetic moments: A microscopic look into the nuclear structure of medium weight and heavy nuclei * Laser trapping of radioactive atoms * Chiral perturbation in dense matter and meson condensation controversy

  11. Carrier and Spin Dynamics in Narrow Gap Parabolic Quantum Well Structures

    Science.gov (United States)

    Bhowmick, M.; Merritt, T.; Khodaparast, G. A.; Mishima, T. D.; Santos, M. B.; Saha, D.; Sanders, G. D.; Stanton, C. J.

    2011-03-01

    Heterostructures with parabolic confinement potentials are important systems to study for many reasons. In a perfect Parabolic Quantum Well (PQW), the subbands are equally spaced and electron-electron interactions are virtually non-existent, allowing coupling of long-wavelength radiation only to the center-of-mass coordinate of the electron system. Narrow band PQW systems are well suited for THz devices because by careful design, one can tune the transition frequency, temperature stability, and narrow-band emission. In our studies, the parabolic confinement was created by an effective parabolic Al compositional gradient inside each well. We studied carrier/spin dynamics in an InSb/AlxIn1 - x Sb multiple- PQW structure using several time resolved differential transmission schemes in the mid-infrared. Our results demonstrate the unique and complex dynamics in InSb heterostructures that can be important for electronic and optoelectronic devices. Supported by: NSF-DMR-0507866, DMR-0520550, DMR-0706313, and NSF-Career Award DMR-0846834.

  12. Role of surface energy on the morphology and optical properties of GaP micro & nano structures grown on polar and non-polar substrates

    Science.gov (United States)

    Roychowdhury, R.; Kumar, Shailendra; Wadikar, A.; Mukherjee, C.; Rajiv, K.; Sharma, T. K.; Dixit, V. K.

    2017-10-01

    Role of surface energy on the morphology, crystalline quality, electronic structure and optical properties of GaP layer grown on Si (001), Si (111), Ge (111) and GaAs (001) is investigated. GaP layers are grown on four different substrates under identical growth kinetics by metal organic vapour phase epitaxy. The atomic force microscopy images show that GaP layer completely covers the surface of GaAs substrate. On the other hand, the surfaces of Si (001), Si (111), Ge (111) substrates are partially covered with crystallographically morphed GaP island type micro and nano-structures. Origin of these crystallographically morphed GaP island is explained by the theoretical calculation of surface energy of the layer and corresponding substrates respectively. The nature of GaP island type micro and nano-structures and layers are single crystalline with existence of rotational twins on Si and Ge (111) substrates which is confirmed by the phi, omega and omega/2theta scans of high resolution x-ray diffraction. The electronic valence band offsets between the GaP and substrates have been determined from the valence band spectra of ultraviolet photoelectron spectroscopy. The valence electron plasmon of GaP are investigated by studying the energy values of Ga (3d) core level along with loss peaks in the energy dependent photoelectron spectra. The peak observed within the range of 3-6 eV from the Ga (3d) core level in the photoelectron spectra are associated to inter band transitions as their energy values are estimated from the pseudo dielectric function by the spectroscopic ellipsometry.

  13. Hydrogen embrittlement of ASTM A 203 D nuclear structural steel

    International Nuclear Information System (INIS)

    Chakravartty, J.K.; Prasad, G.E.; Sinha, T.K.; Asundi, M.K.

    1986-01-01

    The influence of hydrogen on the mechanical properties of ASTM A 203 D nuclear structural steel has been studied by tension, bend and delayed-failure tests at room temperature. While the tension tests of hydrogen charged unnotched specimens reveal no change in ultimate strength and ductility, the effect of hydrogen is manifested in notched specimens (tensile and bend) as a decrease in ultimate strength (maximum load in bend test) and ductility; the effect increases with increasing hydrogen content. It is observed that for a given hydrogen concentration, the decrease in bend ductility is remarkably large compared to that in tensile ductility. Hydrogen charging does not cause any delayed-failure upto 200 h under an applied tensile stress, 0.85 times the notch tensile strength. However delayed failure occurs in hydrogen charged bend samples in less than 10 h under an applied bending load of about 0.80 times of the uncharged maximum load. Fractographs of hydrogen charged unnotched specimens show ductile dimple fracture, while those of notched tension and bend specimens under hydrogen-charged conditions show a mixture of ductile dimple and quasi-cleavage cracking. The proportion of quasi-cleavage cracking increases with increasing hydrogen content and this fracture mode is more predominant in bend specimens. The changes in tensile properties and fracture modes can reasonably be explained by existing theories of hydrogen embrittlement. An attempt is made to explain the significant difference in the embrittlement susceptibility of bend and tensile specimens in the light of difference in triaxiality and plastic zone size near the notch tip. (orig.)

  14. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are

  15. Bridging the gap between event-by-event fluctuation measurements and theory predictions in relativistic nuclear collisions

    Science.gov (United States)

    Braun-Munzinger, P.; Rustamov, A.; Stachel, J.

    2017-04-01

    We develop methods to deal with non-dynamical contributions to event-by-event fluctuation measurements of net-particle numbers in relativistic nuclear collisions. These contributions arise from impact parameter fluctuations and from the requirement of overall net-baryon number or net-charge conservation and may mask the dynamical fluctuations of interest, such as those due to critical endpoints in the QCD phase diagram. Within a model of independent particle sources we derive formulae for net-particle fluctuations and develop a rigorous approach to take into account contributions from participant fluctuations in realistic experimental environments and at any cumulant order. Interestingly, contributions from participant fluctuations to the second and third cumulants of net-baryon distributions are found to vanish at mid-rapidity for LHC energies while higher cumulants of even order are non-zero even when the net-baryon number at mid-rapidity is zero. At lower beam energies the effect of participant fluctuations increases and induces spurious higher moments. The necessary corrections become large and need to be carefully taken into account before comparison to theory. We also provide a procedure for selecting the optimal phase-space coverage of particles for fluctuation analyses and discuss quantitatively the necessary correction due to global charge conservation.

  16. Effect of geometric construction on residual stress distribution in designing a nuclear rotor joined by multipass narrow gap welding

    International Nuclear Information System (INIS)

    Tan, Long; Zhang, Linjie; Zhang, Jianxun; Zhuang, Dong

    2014-01-01

    Highlights: • The internal stress of the pipe is measured using local material removal method. • Bottom protrusion at weld seam can release the stress and mitigate stress evolution. The through-wall axial stress is bending type under the effect of the rotor discs. • The impact of geometric construction on the stress evolution begins after pass 15. - Abstract: The purpose of this study is to investigate the effect of geometric construction on the distribution of residual stresses before and after heat treatment in designing a nuclear welded rotor. The local material removal method was used to measure internal residual stress of the experimental pipe after post weld heat treatment. Three finite element models were employed as follows: a model of experimental pipe, a model with a bottom protrusion existed at the weld region, and a model of two rotor discs butt-welded with a bottom protrusion at the weld region. Investigated results showed that the bottom protrusion existed at the weld region can decrease the residual stress and mitigate the stress evolution significantly on the inner surface. Under the binding effect of the rotor discs, the axial stress of inner surface region is compressive stress; the through-wall axial stress at the weld center line can be deemed to a bending type; both the hoop stress and axial stress at the weld center line on the inner surface are compressive. The impact of geometric construction on the stress evolution at the root bead begins after pass 15 deposited

  17. Selective femtosecond laser structuring of dielectric thin films with different band gaps: a time-resolved study of ablation mechanisms

    Science.gov (United States)

    Rapp, Stephan; Schmidt, Michael; Huber, Heinz P.

    2016-12-01

    Ultrashort pulse lasers have been increasingly gaining importance for the selective structuring of dielectric thin films in industrial applications. In a variety of works the ablation of thin SiO2 and SiNx films from Si substrates has been investigated with near infrared laser wavelengths with photon energies of about 1.2 eV where both dielectrics are transparent (E_{{gap,SiO2}}≈ 8 eV; E_{{gap,SiN}x}≈ 2.5 eV). In these works it was found that few 100 nm thick SiO2 films are selectively ablated with a "lift-off" initiated by confined laser ablation whereas the SiN_{{x}} films are ablated by a combination of confined and direct laser ablation. In the work at hand, ultrafast pump-probe imaging was applied to compare the laser ablation dynamics of the two thin film systems directly with the uncoated Si substrate—on the same setup and under identical parameters. On the SiO2 sample, results show the pulse absorption in the Si substrate, leading to the confined ablation of the SiO2 layer by the expansion of the substrate. On the SiN_{{x}} sample, direct absorption in the layer is observed leading to its removal by evaporation. The pump-probe measurements combined with reflectivity corrected threshold fluence investigations suggest that melting of the Si substrate is sufficient to initiate the lift-off of an overlaying transparent film—evaporation of the substrate seems not to be necessary.

  18. Accelerating Full Configuration Interaction Calculations for Nuclear Structure

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chao; Sternberg, Philip; Maris, Pieter; Ng, Esmond; Sosonkina, Masha; Le, Hung Viet; Vary, James; Yang, Chao

    2008-04-14

    One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and correspondingeigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significant challenge to the design and implementation of efficient and scalable algorithms for obtaining solutions on massively parallel computer systems. In this paper, we describe the computational strategies employed in a state-of-the-art FCI code MFDn (Many Fermion Dynamics - nuclear) as well as techniques we recently developed to enhance the computational efficiency of MFDn. We will demonstrate the current capability of MFDn and report the latest performance improvement we have achieved. We will also outline our future research directions.

  19. Nuclear structure considerations for gamma-ray lasers

    International Nuclear Information System (INIS)

    Strottman, D.; Arthur, E.D.; Madland, D.G.

    1985-01-01

    Presented are initial results in our investigation of the nuclear physics issues of gamma-ray lasers. These include the questions of what is known from existing experimental data, where does one optimally search for nuclei displaying simultaneously both closely lying levels and nuclear isomerism, and which theoretical models does one employ for systematic searches for candidate nuclei and for calculation of detailed candidate level properties

  20. Structure and Activities of Nuclear Medicine in Kuwait.

    Science.gov (United States)

    Elgazzar, Abdelhamid H; Owunwanne, Azuwuike; Alenezi, Saud

    2016-07-01

    The practice of nuclear medicine in Kuwait began in 1965 as a clinic for treating thyroid diseases. The practice developed gradually and until 1981 when the Faculty of Medicine established the Division of Nuclear Medicine in the Department of Radiology, which later became a separate department responsible for establishing and managing the practice in all hospitals of Kuwait. In 1987, a nuclear medicine residency program was begun and it is administered by Kuwait Institute for Medical Specializations originally as a 4-year but currently as a 5-year program. Currently there are 11 departments in the ministry of health hospitals staffed by 49 qualified attending physicians, mostly the diplomats of the Kuwait Institute for Medical Specializations nuclear medicine residency program, 4 academic physicians, 2 radiopharmacists, 2 physicists, and 130 technologists. These departments are equipped with 33 dual-head gamma cameras, 10 SPET/CT, 5 PET/CT, 2 cyclotrons, 1 breast-specific gamma imaging, 1 positron-emitting mammography, 10 thyroid uptake units, 8 technegas machines, 7 PET infusion systems, and 8 treadmills. Activities of nuclear medicine in Kuwait include education and training, clinical service, and research. Education includes nuclear medicine technology program in the Faculty of Allied Health Sciences, the 5-year residency program, medical school teaching distributed among different modules of the integrated curriculum with 14 didactic lecture, and other teaching sessions in nuclear medicine MSc program, which run concurrently with the first part of the residency program. The team of Nuclear Medicine in Kuwait has been active in research and has published more than 300 paper, 11 review articles, 12 book chapters, and 17 books in addition to 36 grants and 2 patents. A PhD program approved by Kuwait University Council would begin in 2016. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. DISCOVERY OF A TWO-ARMED SPIRAL STRUCTURE IN THE GAPPED DISK AROUND HERBIG Ae STAR HD 100453

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Kevin; Apai, Daniel [Department of Astronomy/Steward Observatory, The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Kasper, Markus [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Robberto, Massimo, E-mail: kwagner@as.arizona.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2015-11-01

    We present Very Large Telescope (VLT)/SPHERE adaptive optics imaging in the Y-, J-, H-, and K-bands of the HD 100453 system and the discovery of a two-armed spiral structure in a disk extending to 0.″37 (∼42 AU) from the star, with highly symmetric arms to the northeast and southwest. Inside of the spiral arms, we resolve a ring of emission from 0.″18 to 0.″25 (∼21–29 AU). By assuming that the ring is intrinsically circular we estimate an inclination of ∼34° from face on. We detect dark crescents on opposite sides (NW and SE) that begin at 0.″18 and continue to radii smaller than our inner working angle of 0.″15, which we interpret as the signature of a gap at ≲21 AU that has likely been cleared by forming planets. We also detect the ∼120 AU companion HD 100453 B, and by comparing our data to 2003 Hubble Space Telescope and VLT/NACO images we estimate an orbital period of ∼850 year. We discuss what implications the discovery of the spiral arms and finer structures of the disk may have on our understanding of the possible planetary system in HD 100453 and how the morphology of this disk compares to other related objects.

  2. Probing the Electronic Structure and Band Gap Evolution of Titanium Oxide Clusters (TiO2)n- (n=1-10) Using Photoelectron Spectroscopy

    International Nuclear Information System (INIS)

    Zhai, Hua-jin; Wang, Lai S.

    2007-01-01

    TiO2 is a wide-band gap semiconductor and it is an important material for photocatalysis. Here we report an experimental investigation of the electronic structure of (TiO2)n clusters and how their band gap evolves as a function of size using anion photoelectron spectroscopy (PES). PES spectra of (TiO2)n- clusters for n = 1-10 have been obtained at 193 (6.424 eV) and 157 nm (7.866 eV). The high photon energy at 157 nm allows the band gap of the TiO2 clusters to be clearly revealed up to n = 10. The band gap is observed to be strongly size-dependent for n 1 appears to be localized in a tricoordinated Ti atom, creating a single Ti3+ site and making these clusters ideal molecular models for mechanistic understanding of TiO2 surface defects and photocatalytic properties

  3. PREFACE: 11th International Spring Seminar on Nuclear Physics: Shell Model and Nuclear Structure - achievements of the past two decades

    Science.gov (United States)

    2015-02-01

    The 11th International Seminar on Nuclear Physics was held in Ischia from May 12 to May 16, 2014. This Seminar was dedicated to Aldo Covello, who has been the promoter of this series of meetings, which started in Sorrento in 1986 and continued with meetings held every two or three years in the Naples area. Aldo's idea was to offer to a group of researchers, actively working in selected fields of Nuclear Physics, the opportunity to confront their points of view in a lively and informal way. The choice for the period of the year, Spring, as well as the sites chosen reflected this intent. The first meeting was of a purely theoretical nature, but it was immediately clear that the scope of these conferences needed to be enlarged calling into play the experimental community. Then, starting from the second meeting, all the following ones have been characterized by fruitful discussion between theoretical and experimental researchers on current achievements and future developments of nuclear structure. This may be read, in fact, as one of the motivating factors for Aldo's election as Fellow of the American Physical Society in 2008 "... for his outstanding contributions to the international nuclear physics community by providing, for over two decades, a venue for theorists and experimentalists to share their latest ideas." The present meeting, organized by Aldo's former students and with the benefit of his suggestions, has maintained this tradition. The title "Shell model and nuclear structure: achievements of the past two decades" recalls that of the 2nd International Spring Seminar "Shell Model and Nuclear Structure: where do we stand?". The main aim of this 11th Seminar was, in fact, to discuss the changes of the past two decades on our view of nuclei in terms of shell structure as well as the perspectives of the shell model, which has been one of the key points in Aldo's research. This point is well accounted by the Opening Speech of Igal Talmi, one of the fathers of the

  4. [Structure and function of nuclear matrix associated regions (S/MARs)].

    Science.gov (United States)

    Chernov, I P; Akopov, S B; Nikolaev, L G

    2004-01-01

    Modern concepts on the chromatin loop-domain organization and the role of the DNA regions specifically binding the nuclear matrix (nuclear scaffold, or S/MARs) in its formation, maintenance, and regulation are discussed. Some S/MAR structural features, properties of binding the nuclear matrix, and probable mechanisms of their involvement in regulation of gene activity are considered. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 1; see also http://www.maik.ru.

  5. Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

    Directory of Open Access Journals (Sweden)

    Ji Chen

    2016-01-01

    Full Text Available We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

  6. Structure of nuclei with masses 76 and 82 and nuclear matrix elements of neutrinoless double beta decay

    Science.gov (United States)

    Yoshinaga, N.; Yanase, K.; Higashiyama, K.; Teruya, E.; Taguchi, D.

    2018-02-01

    Nuclear shell-model calculations are carried out for isobaric nuclei with masses 76 and 82. Energy spectra and electromagnetic transition rates are compared with the experimental data. Using the wavefunctions thus obtained, nuclear matrix elements for the neutrinoless double beta decay are estimated. In order to investigate the model dependence on the nuclear matrix elements, pair-truncated shell-model calculations are also performed. By comparing the results with those in other models, the nuclear matrix elements are found to be sensitive to the ground-state correlations. In particular, nuclear matrix elements have strong correlations with pairing gaps.

  7. Structural and thermal properties of ternary narrow-gap oxide semiconductor; wurtzite-derived β-CuGaO2.

    Science.gov (United States)

    Nagatani, Hiraku; Suzuki, Issei; Kita, Masao; Tanaka, Masahiko; Katsuya, Yoshio; Sakata, Osami; Miyoshi, Shogo; Yamaguchi, Shu; Omata, Takahisa

    2015-02-16

    The crystal structure of the wurtzite-derived β-CuGaO2 was refined by Rietveld analysis of high-resolution powder diffraction data obtained from synchrotron X-ray radiation. Its structural characteristics are discussed in comparison with the other I-III-VI2 and II-VI oxide semiconductors. The cation and oxygen tetrahedral distortions of the β-CuGaO2 from an ideal wurtzite structure are small. The direct band-gap nature of the β-CuGaO2, unlike β-Ag(Ga,Al)O2, was explained by small cation and oxygen tetrahedral distortions. In terms of the thermal stability, the β-CuGaO2 irreversibly transforms into delafossite α-CuGaO2 at >460 °C in an Ar atmosphere. The transformation enthalpy was approximately -32 kJ mol(-1), from differential scanning calorimetry. This value is close to the transformation enthalpy of CoO from the metastable zincblende form to the stable rock-salt form. The monovalent copper in β-CuGaO2 was oxidized to divalent copper in an oxygen atmosphere and transformed into a mixture of CuGa2O4 spinel and CuO at temperatures >350 °C. These thermal properties indicate that β-CuGaO2 is stable at ≤300 °C in both reducing and oxidizing atmospheres while in its metastable form. Consequently, this material could be of use in optoelectronic devices that do not exceed 300 °C.

  8. Perspectives for nuclear structure research at GSI: from halo nuclei to superheavy elements

    International Nuclear Information System (INIS)

    Muenzenberg, G.

    1997-11-01

    After a brief overview on recent advances in the investigation of nuclei at the driplines and the upper end of the nuclear table key issues of nuclear structure research as adressed by new theoretical developments will be discussed in context with new developments in heavy-ion accelerators and experimental techniques. (orig.)

  9. NESSY, a relational PC database for nuclear structure and decay data

    International Nuclear Information System (INIS)

    Boboshin, I.N.; Varlamov, V.V.; Trukhanov, S.K.

    1994-11-01

    The universal relational database NESSY (New ENSDF Search SYstem) based on the international ENSDF system (Evaluated Nuclear Structure Data File) is described. NESSY, which was developed for IBM compatible PC, provides high efficiency processing of ENSDF information for searches and retrievals of nuclear physics data. The principle of the database development and examples of applications are presented. (author)

  10. Nuclear shapes: from earliest ideas to multiple shape coexisting structures

    International Nuclear Information System (INIS)

    Heyde, K; Wood, J L

    2016-01-01

    The concept of the atomic nucleus being characterized by an intrinsic property such as shape came as a result of high precision hyperfine studies in the field of atomic physics, which indicated a non-spherical nuclear charge distribution. Herein, we describe the various steps taken through ingenious experimentation and bold theoretical suggestions that mapped the way for later work in the early 50s by Aage Bohr, Ben Mottelson and James Rainwater. We lay out a long and winding road that marked, in the period of 50s to 70s, the way shell-model and collective-model concepts were reconciled. A rapid increase in both accelerator and detection methods (70s towards the early 2000s) opened new vistas into nuclear shapes, and their coexistence, in various regions of the nuclear mass table. Next, we outline a possible unified view of nuclear shapes: emphasizing decisive steps taken as well as questions remaining, next to the theoretical efforts that could result in an emerging understanding of nuclear shapes, building on the nucleus considered as a strongly interacting system of nucleons as the microscopic starting point. (invited comment)

  11. New nuclear projects: structure, supply chain and financing

    International Nuclear Information System (INIS)

    Keppler, J.H.; Cometto, M.

    2015-01-01

    In 2015 there were 68 reactors being constructed throughout the world and 159 projects were planned. The projects for the construction of nuclear reactors face challenging issues like financing and management. The NEA (Nuclear Energy Agency) has analysed the feedback experience on a sample of reactor projects and of reactors recently commissioned in order to draw lessons on 3 issues: financing, long-term electricity price, and project management including the supply chain. It is already known that technologies requiring high initial capital like nuclear power or renewable energies, are very sensitive to the long-term price of electricity. The study shows that for a debt ratio below 60%, the risk for the investor is low even if the long-term electricity price drops by 30 %. Because of the complexity of the construction of a nuclear power plant there are mainly 3 types of project management: the turnkey project, the split package approach (a relatively low number of suppliers) and the multi-contract approach. The turnkey approach is favoured by the new entrants in the nuclear world. The harmonization of regulations and the convergence of the safety requirements are necessary to build an efficient and competitive supply chain. (A.C.)

  12. 61. International conference NUCLEUS-2011 on problems of nuclear spectroscopy and structure of atomic nucleus. Book of abstracts

    International Nuclear Information System (INIS)

    2011-01-01

    The program of the 61th International conference NUCLEUS-2011 covers almost all actual problems of nuclear physics. The recent results of theoretical and experimental investigations of nuclear structure as well as nuclear reactions are presented. The fundamental problems of nuclear physics are discussed. The current achievements in the field of nuclear instrumentation and experimental techniques are considered. The considerable attention is given to modern nuclear databases as scientific research tools [ru

  13. Boson-exchange nucleon-nucleon potential and nuclear structure

    International Nuclear Information System (INIS)

    Grange, Pierre.

    1976-01-01

    A fully momentum-dependent one-boson-exchange potential is derived which takes into account the mesons, π, eta, sigma, rho, ω and phi. Scattering bound states and nuclear matter properties are studied in momentum space. The use of such potential is shown to be as easy as the use of more simple phenomenological interactions. In nuclear matter the formalism of Bethe-Goldstone is chosen to compute the binding energy versus density in the approximation of two-body and three-body correlations. The three-body correlated wave function obtained is then used [fr

  14. Proceedings of the Conference on Structural Analysis and Design of Nuclear Power Plants. v. 1

    International Nuclear Information System (INIS)

    1984-01-01

    It's presented the discussion of recents research results and developments related to applications of structural mechanics to nuclear power plants, in particular, and to conventional power plants, in a more general context. (E.G.) [pt

  15. Theoretical aspects of photonic band gap in 1D nano structure of LN: MgLN periodic layer

    International Nuclear Information System (INIS)

    Sisodia, Namita

    2015-01-01

    By using the transfer matrix method, we have analyzed the photonic band gap properties in a periodic layer of LN:MgLN medium. The Width of alternate layers of LN and MgLN is in the range of hundred nanometers. The birefringent and ferroelectric properties of the medium (i.e ordinary, extraordinary refractive indices and electric dipole moment) is given due considerations in the formulation of photonic band gap. Effect of electronic transition dipole moment of the medium on photonic band gap is also taken into account. We find that photonic band gap can be modified by the variation in the ratio of the width of two medium. We explain our findings by obtaining numerical values and the effect on the photonic band gap due to variation in the ratio of alternate medium is shown graphically

  16. Structural Aging Program to evaluate continued performance of safety-related concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1994-01-01

    This report discusses the Structural Aging (SAG) Program which is being conducted at the Oak Ridge National Laboratory (ORNL) for the United States Nuclear Regulatory commission (USNRC). The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. The program is organized into three technical tasks: Materials Property Data Base, Structural Component Assessment/Repair Technologies, and Quantitative Methodology for continued Service Determinations. Objectives and a summary of recent accomplishments under each of these tasks are presented

  17. Structural aging program to evaluate continued performance of safety-related concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1994-01-01

    The Structural Aging (SAG) Program is being conducted at the Oak Ridge National Laboratory (ORNL) for the United States Nuclear Regulatory Commission (USNRC). The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. The program is organized into three technical tasks: Materials Property Data Base, Structural Component Assessment/Repair Technologies, and Quantitative Methodology for Continued Service Determinations. Objectives and a summary of recent accomplishments under each of these tasks are presented. (Author)

  18. Nuclear hormone receptor architecture - form and dynamics: The 2009 FASEB Summer Conference on Dynamic Structure of the Nuclear Hormone Receptors.

    Science.gov (United States)

    McEwan, Iain J; Nardulli, Ann M

    2009-12-31

    Nuclear hormone receptors (NHRs) represent a large and diverse family of ligand-activated transcription factors involved in regulating development, metabolic homeostasis, salt balance and reproductive health. The ligands for these receptors are typically small hydrophobic molecules such as steroid hormones, thyroid hormone, vitamin D3 and fatty acid derivatives. The first NHR structural information appeared approximately 20 years ago with the solution and crystal structures of the DNA binding domains and was followed by the structure of the agonist and antagonist bound ligand binding domains of different NHR members. Interestingly, in addition to these defined structural features, it has become clear that NHRs also possess significant structural plasticity. Thus, the dynamic structure of the NHRs was the topic of a recent stimulating and informative FASEB Summer Research Conference held in Vermont.

  19. Structure and function design for nuclear facilities decommissioning information database

    International Nuclear Information System (INIS)

    Liu Yongkuo; Song Yi; Wu Xiaotian; Liu Zhen

    2014-01-01

    The decommissioning of nuclear facilities is a radioactive and high-risk project which has to consider the effect of radiation and nuclear waste disposal, so the information system of nuclear facilities decommissioning project must be established to ensure the safety of the project. In this study, by collecting the decommissioning activity data, the decommissioning database was established, and based on the database, the decommissioning information database (DID) was developed. The DID can perform some basic operations, such as input, delete, modification and query of the decommissioning information data, and in accordance with processing characteristics of various types of information data, it can also perform information management with different function models. On this basis, analysis of the different information data will be done. The system is helpful for enhancing the management capability of the decommissioning process and optimizing the arrangements of the project, it also can reduce radiation dose of the workers, so the system is quite necessary for safe decommissioning of nuclear facilities. (authors)

  20. Nuclear structure at high spin using multidetector gamma array and ...

    Indian Academy of Sciences (India)

    2014-04-05

    Apr 5, 2014 ... erator Centre, New Delhi. The rolled 209Bi target thickness was 3.5 mg/cm2. Beam was pulsed at 4 MHz to measure lifetimes of nuclear isomers by electronics method. GDA used in the present work has improved the quality of coincidence spectra, enabling us to identify and place several weak transitions ...

  1. Book of abstracts of International Conference on Nuclear Structure and Dynamics 2009

    International Nuclear Information System (INIS)

    Prepolec, L.; Niksic, T.

    2009-01-01

    Following the long tradition of nuclear physics conferences organized by our two institutes, e.g. the Adriatic International Conference and Europhysics Study Conferences, this meeting will provide a broad discussion forum on recent experimental and theoretical advances in the physics of nuclear structure and reactions. The main focus will be on the following topics: Nuclear structure and reactions far from stability; Exotic modes of excitation and decays; Collective phenomena and symmetries; Ab initio, cluster model, and shell-model approaches; Nuclear energy density functionals; Heavy-ion reactions at near-barrier energies; Dynamics of light-ion reactions; Nuclear reactions of astrophysical interest; Weak-interaction processes. This booklet contains the abstracts of contributions which will be presented at the Conference, either as invited and contributed talks, or oral poster presentations

  2. Nuclear structure theory. Annual technical progress report, 1 July 1974--30 June 1975

    International Nuclear Information System (INIS)

    French, J.B.; Koltun, D.S.

    1975-01-01

    Progress during the past year is summarized for the following areas of nuclear structure and reaction theory: Meson interactions with nucleons and nuclei, including inelastic scattering of pions, three-body theories of scattering and absorption of pions by deuterons, and π-p bremsstrahlung. Theory of the effective interaction, including behavior of the expansion in orders of the reaction matrix. Statistical spectroscopy including fluctuations in energy levels and excitation strengths, and sum rules and strength distributions for various excitation processes, including single-nucleon transfer, β decay and multipole giant resonances. Studies of the inverse scattering problem. Studies of nuclear symmetries, of nuclear clustering, and of general nuclear structure by α-transfer reactions, and of nuclear shapes by (d, 3 He) reactions. (U.S.)

  3. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators

    Energy Technology Data Exchange (ETDEWEB)

    Ricard-McCutchan, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dimitriou, P. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Nichols, A. L. [Univ. of Surrey, Guildford (United Kingdom)

    2015-08-01

    The 21st meeting of the International Network of Nuclear Structure and Decay Data Evaluators was convened at the IAEA Headquarters, Vienna, from 20 to 24 April 2015 under the auspices of the IAEA Nuclear Data Section. This meeting was attended by 36 scientists from 15 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, data centre reports, various proposals considered, and actions agreed by the participants, as well as recommendations/conclusions are presented within this document.

  4. Nuclear analysis of structural damage and nuclear heating on enhanced K-DEMO divertor model

    Science.gov (United States)

    Park, J.; Im, K.; Kwon, S.; Kim, J.; Kim, D.; Woo, M.; Shin, C.

    2017-12-01

    This paper addresses nuclear analysis on the Korean fusion demonstration reactor (K-DEMO) divertor to estimate the overall trend of nuclear heating values and displacement damages. The K-DEMO divertor model was created and converted by the CAD (Pro-Engineer™) and Monte Carlo automatic modeling programs as a 22.5° sector of the tokamak. The Monte Carlo neutron photon transport and ADVANTG codes were used in this calculation with the FENDL-2.1 nuclear data library. The calculation results indicate that the highest values appeared on the upper outboard target (OT) area, which means the OT is exposed to the highest radiation conditions among the three plasma-facing parts (inboard, central and outboard) in the divertor. Especially, much lower nuclear heating values and displacement damages are indicated on the lower part of the OT area than others. These are important results contributing to thermal-hydraulic and thermo-mechanical analyses on the divertor and also it is expected that the copper alloy materials may be partially used as a heat sink only at the lower part of the OT instead of the reduced activation ferritic-martensitic steel due to copper alloy’s high thermal conductivity.

  5. Theoretical nuclear structure and astrophysics. Progress report for 1996

    Energy Technology Data Exchange (ETDEWEB)

    Guidry, M.W.; Nazarewicz, W.; Strayer, M.R.

    1996-12-31

    This research effort is directed toward theoretical support and guidance for the fields of radioactive ion beam physics, gamma ray spectroscopy, computational and nuclear astrophysics, and the interface between these disciplines. The authors report substantial progress in all those areas. One measure of progress is publications and invited material. The research described here has led to more than 43 papers that are published, accepted, or submitted to refereed journals, and to 15 invited presentations at conferences and workshops.

  6. Development of an automated fracture assessment system for nuclear structures

    International Nuclear Information System (INIS)

    Mikkola, T.P.J.; Raiko, H.

    1991-01-01

    A program system for automated fracture mechanical analyses with three dimensional (3D) finite element (FE) models has been developed. The accuracy of the generated models is widely tested. The system is aimed at safety analyses of nuclear power plant components. Moreover, the results of the fracture mechanical FE-analyses can be implemented in an easy to use fracture assessment program based on the use of weight functions. (author)

  7. Theoretical nuclear structure and astrophysics. Progress report for 1996

    International Nuclear Information System (INIS)

    Guidry, M.W.; Nazarewicz, W.; Strayer, M.R.

    1996-01-01

    This research effort is directed toward theoretical support and guidance for the fields of radioactive ion beam physics, gamma ray spectroscopy, computational and nuclear astrophysics, and the interface between these disciplines. The authors report substantial progress in all those areas. One measure of progress is publications and invited material. The research described here has led to more than 43 papers that are published, accepted, or submitted to refereed journals, and to 15 invited presentations at conferences and workshops

  8. Nuclear structure and gene activity in human differentiated cells

    Czech Academy of Sciences Publication Activity Database

    Bártová, Eva; Kozubek, Stanislav; Jirsová, Pavla; Kozubek, Michal; Gajová, H.; Lukášová, Emilie; Skalníková, M.; Cafourková, Alena; Koutná, I.; Hausmann, M.

    2002-01-01

    Roč. 139, č. 2 (2002), s. 76-89 ISSN 1047-8477 R&D Projects: GA AV ČR IBS5004010; GA AV ČR IAB5004102; GA ČR GA301/01/0186 Institutional research plan: CEZ:AV0Z5004920 Keywords : nuclear compartments * gene expression * FISH Subject RIV: BO - Biophysics Impact factor: 4.194, year: 2002

  9. The J/ψ way to nuclear structure

    International Nuclear Information System (INIS)

    Caldwell, A.; Kowalski, H.

    2009-09-01

    We propose to investigate the properties of nuclear matter by measuring the elastic scattering of J/ψ on nuclei with high precision. The J/ψ mesons are produced from the photons emitted in high energy electron-proton or electron-nucleus scattering in the low-x region. The measurement could be performed at the future ENC, EIC or LHeC facilities. (orig.)

  10. Structural role of molybdenum in nuclear glasses: an EXAFS study

    International Nuclear Information System (INIS)

    Calas, G.; Le Grand, M.; Galoisy, L.; Ghaleb, D.

    2003-01-01

    The Mo environment has been investigated in inactive nuclear glasses using extended X-ray absorption spectroscopy (XAS). Mo is present in a tetrahedron coordinated to oxygen in the form of molybdate groups [MoO 4 ] 2- (d(Mo-O)=1.78 A). This surrounding is not affected by the presence of noble metal phases in the nuclear glass. Relying on the XAS results, on the bond-valence model and on molecular dynamics simulations of a simplified borosilicate model glass, we show that these groups are not directly linked to the borosilicate network but rather located within alkali and alkaline-earth rich domains in the glass. This specific location in the glass network is a way to understand the low solubility of Mo in glasses melted under oxidizing conditions. It also explains the possible phase separation of a yellow phase enriched in alkali molybdates in molten nuclear glasses or the nucleation of calcium molybdates during thermal aging of these glasses. Boron coordination changes in the molten and the glassy states may explain the difference in the composition of the crystalline molybdates, as they exert a direct influence on the activity of alkalis in borosilicate glasses and melts

  11. Establishing a Nuclear Industrial Structure The Spanish Case

    International Nuclear Information System (INIS)

    Palacios, L.

    1989-01-01

    Nuclear industry is nationalistic all over the world. This fact is at first glance rather surprising, since one would guess that the localization drive should start with segments of industry of a less sophisticated nature. The reason probably lies on the fact that nuclear disciplines are new and can be conceived as an easier task for planners than other techniques where industrial relationships are already established. The process of increasing domestic content has important implications and crucial decisions have to be made. A general process of technology transfer has to be assured, investments have to be made in new plant and a sizable number of engineers and technicians has to be trained. Technology transfer in the nuclear field seems to be the practical extent dictated by the availability of raw materials and the economy of scale for some components. Table V lists the content achieved in specific classes of equipment. The process has been successful and has enabled Spanish Industry to be present in the world market. Countries embarking in similar programs have expressed interest in the Spanish process as representative of medium development industry that, by determination and serious work, has achieved an advanced status, overcoming deficiencies that are not normally encountered in more developed societies. Spanish Industry is of course ready to share its experience with interested parties, thus contributing to orient local industries by advising them on the successes achieved as an example to follow, and the mistakes made, to prevent occurrence

  12. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent

    2003-01-01

    , assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  13. Significance of Alkali-Silica reaction in nuclear safety-related concrete structures

    International Nuclear Information System (INIS)

    Le Pape, Y.; Field, K.G.; Mattus, C.H.; Naus, D.J.; Busby, J.T.; Saouma, V.; Ma, Z.J.; Cabage, J.V.; Guimaraes, M.

    2015-01-01

    Nuclear Power Plant license renewal up to 60 years and possible life extension beyond has established a renewed focus on long-term aging of nuclear generating stations materials, and particularly, on concrete. Large irreplaceable sections of most nuclear generating stations include concrete components. The Expanded Materials Degradation Analysis, jointly performed by the Department of Energy, the U.S. Nuclear Regulatory Commission, the Academia and the Power Generation Industry, identified the need to develop a consistent knowledge base of alkali-silica reaction (ASR) within concrete as an urgent priority (Graves et al., 2014). ASR results in an expansion of Concrete produced by the reaction between alkali (generally from cement), reactive aggregate (like amorphous silica) and water absorption. ASR causes expansion, cracking and loss of mechanical properties. Considering that US commercial reactors in operation enter the age when ASR distress can be potentially observed and that numerous non-nuclear infrastructures (transportation, energy production) in a majority of the States have already experienced ASR-related concrete degradation, the susceptibility and significance of ASR for nuclear concrete structures must be addressed. This paper outlines an on-going research program including the investigation of the possibility of ASR in nuclear power plants, and the assessment of the residual shear bearing capacity of ASR-subjected nuclear structures. (authors)

  14. Gap Resolution

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-25

    Gap Resolution is a software package that was developed to improve Newbler genome assemblies by automating the closure of sequence gaps caused by repetitive regions in the DNA. This is done by performing the follow steps:1) Identify and distribute the data for each gap in sub-projects. 2) Assemble the data associated with each sub-project using a secondary assembler, such as Newbler or PGA. 3) Determine if any gaps are closed after reassembly, and either design fakes (consensus of closed gap) for those that closed or lab experiments for those that require additional data. The software requires as input a genome assembly produce by the Newbler assembler provided by Roche and 454 data containing paired-end reads.

  15. Gap junctions.

    Science.gov (United States)

    Goodenough, Daniel A; Paul, David L

    2009-07-01

    Gap junctions are aggregates of intercellular channels that permit direct cell-cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues. Their long evolutionary history has permitted adaptation of gap-junctional intercellular communication to a variety of functions, with multiple regulatory mechanisms. Gap-junctional channels are composed of hexamers of medium-sized families of integral proteins: connexins in chordates and innexins in precordates. The functions of gap junctions have been explored by studying mutations in flies, worms, and humans, and targeted gene disruption in mice. These studies have revealed a wide diversity of function in tissue and organ biology.

  16. IAEA advisory group meeting on nuclear structure and decay data, Zeist, The Netherlands, 11-14 May 1982

    International Nuclear Information System (INIS)

    Lorenz, A.

    1982-08-01

    The IAEA Nuclear Data Section convened the fifth meeting of the international nuclear structure and decay data network at Zeist near Utrecht, in The Netherlands, 11-14 May 1982. The meeting was attended by 24 scientists from 11 Member States and 2 international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. (author)

  17. IAEA advisory group meeting on nuclear structure and decay data. IAEA, Vienna 21-25 April 1980

    International Nuclear Information System (INIS)

    Lorenz, A.

    1980-10-01

    The IAEA Nuclear Data Section convened the fourth meeting of the international nuclear structure and decay data network at IAEA Headquarters in Vienna, Austria, from 21-25 April 1980. The meeting was attended by 23 Scientists from 11 Member States and 2 international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. (author)

  18. Capacitance-voltage characteristics of metal-insulator-semiconductor structures based on graded-gap HgCdTe with various insulators

    Energy Technology Data Exchange (ETDEWEB)

    Voitsekhovskii, A.V., E-mail: vav@elefot.tsu.ru [Department of Radiophysics, Tomsk State University, Lenin av., 36, 634050, Tomsk (Russian Federation); Laboratory of Optical Electronics, Siberian Physical Technical Institute TSU, Novosobornaya sq., 1, 634050, Tomsk (Russian Federation); Nesmelov, S.N., E-mail: nes@elefot.tsu.ru [Laboratory of Optical Electronics, Siberian Physical Technical Institute TSU, Novosobornaya sq., 1, 634050, Tomsk (Russian Federation); Dzyadukh, S.M. [Laboratory of Optical Electronics, Siberian Physical Technical Institute TSU, Novosobornaya sq., 1, 634050, Tomsk (Russian Federation)

    2012-11-01

    Metal-insulator-semiconductor structures based on HgCdTe are grown by molecular-beam epitaxy. Near-surface graded-gap layers with a high CdTe content are inserted on both sides of the epitaxial HgCdTe film. The capacitance-voltage characteristics of these structures are studied experimentally. The main characteristics of these graded-gap HgCdTe structures are determined taking into account the effect of the non-uniform composition of the near-surface layers on the measured parameters. The capacitance-voltage characteristics of the graded-gap HgCdTe structures with various insulators are examined and the densities of surface states, densities of fixed and mobile charges are evaluated. The properties of the interface for CdTe grown in situ are found to be fairly good. We found that for structures based on HgCdTe-CdTe typical of very low density of mobile charges, the density of fixed charge does not exceed a 5.5 Multiplication-Sign 10{sup 10} cm{sup -2}. - Highlights: Black-Right-Pointing-Pointer The metal-insulator-semiconductor structures based on HgCdTe were studied. Black-Right-Pointing-Pointer A method is proposed for investigation of these graded-gap structures. Black-Right-Pointing-Pointer The properties of the interface HgCdTe with some insulators were investigated. Black-Right-Pointing-Pointer The properties of the interface for CdTe are found to be fairly good.

  19. An introduction to using the FORTRAN programs provided with Computational Nuclear Physics 1 Nuclear Structure

    Science.gov (United States)

    Boytos, Matthew A.; Norbury, John W.

    1992-01-01

    The authors of this paper have provided a set of ready-to-run FORTRAN programs that should be useful in the field of theoretical nuclear physics. The purpose of this document is to provide a simple synopsis of the programs and their use. A separate section is devoted to each program set and includes: abstract; files; compiling, linking, and running; obtaining results; and a tutorial.

  20. Theoretical studies in nuclear reaction and nuclear structure. Progress report, August 1, 1977--July 31, 1978

    International Nuclear Information System (INIS)

    MacDonald, W.M.; Redish, E.F.

    1978-01-01

    The research program covers four major areas of nuclear theory: reaction theory including both few-body and many-body systems, intermediate energy reactions including nucleon-nucleon processes, pion physics, and nuclear dynamics. In many-body reaction theory the major achievement has been the development of a unitary and connected Hamiltonian formulation adapted to approximate calculations which include 3-body channels. A new analysis of isobaric analog states attracts high resolution data parameters which characterize these states and provide information about the nucleon-nucleon interaction. The multiple-scattering analysis of approximately GeV proton-nucleus scattering has been validated by agreement in absolute magnitude with new experimental data, and contributions of a nucleon isobar were identified. The Banerjee-Cammarata dynamical theory of the pion-nucleon interaction has been found to satisfy several independent tests of dispersion relations as well as predicting experimental phase shifts. In nuclear dynamics a new S-matrix theory of time-dependent Hartree-Fock promises to provide a new approach to heavy-ion reactions. A list of publications is included