WorldWideScience

Sample records for weak collective pinning

  1. Collective-pinning properties of superconducting a-NbxGe and a-MoxSi films

    International Nuclear Information System (INIS)

    Woerdenweber, R.

    1987-01-01

    This thesis describes a study of superconducting flux pinning in amorphous NbGe and MoSi films of various compositions and thickness. Amorphous NbGe and MoSi alloys belong to the weak-coupling type-II superconductors in the extreme dirty limit. This feature enables to determine several important superconducting parameters from well-known theoretical expressions. It is also responsible for the weak pinning, which is necessary to observe the two-dimensional collective pinning properties according to the Larkin-Ovchinnikov theory. (Auth.)

  2. Critical points in the Bragg glass phase of a weakly pinned crystal of ...

    Indian Academy of Sciences (India)

    the dynamical annealing of the disordered bundles of vortices injected through the sample edges towards the destined ... weakly pinned crystals of the systems like, 2H-NbSe2 and the cubic (C15) CeRu2. [12]. ... systems. This in turn im- ..... We show in figure 6 an updated version of the vortex phase diagram in the given.

  3. Interplay between collective pinning and artificial defects on domain wall propagation in Co/Pt multilayers

    International Nuclear Information System (INIS)

    Rodriguez-Rodriguez, G; Hierro-Rodriguez, A; Perez-Junquera, A; Montenegro, N; Alameda, J M; Velez, M; Menendez, J L; Ravelosona, D

    2010-01-01

    The interplay between collective pinning on intrinsic structural defects and artificial pinning at a patterned hole is studied in magnetic multilayers with perpendicular anisotropy. The pinning strength of a patterned hole is measured through its efficiency to stop domain wall (DW) propagation into a consecutive unpatterned nanowire section (using antisymmetric magnetoresistance to detect the direction of DW propagation) whereas collective pinning is characterized by the field dependence of DW velocity. Close to room temperature, collective pinning becomes weaker than artificial pinning so that pinning at the hole compensates nucleation-pad geometry, blocking DW propagation across the nanowire.

  4. Stochastic Resonance in an Underdamped System with Pinning Potential for Weak Signal Detection

    Directory of Open Access Journals (Sweden)

    Haibin Zhang

    2015-08-01

    Full Text Available Stochastic resonance (SR has been proved to be an effective approach for weak sensor signal detection. This study presents a new weak signal detection method based on a SR in an underdamped system, which consists of a pinning potential model. The model was firstly discovered from magnetic domain wall (DW in ferromagnetic strips. We analyze the principle of the proposed underdamped pinning SR (UPSR system, the detailed numerical simulation and system performance. We also propose the strategy of selecting the proper damping factor and other system parameters to match a weak signal, input noise and to generate the highest output signal-to-noise ratio (SNR. Finally, we have verified its effectiveness with both simulated and experimental input signals. Results indicate that the UPSR performs better in weak signal detection than the conventional SR (CSR with merits of higher output SNR, better anti-noise and frequency response capability. Besides, the system can be designed accurately and efficiently owing to the sensibility of parameters and potential diversity. The features also weaken the limitation of small parameters on SR system.

  5. Stochastic Resonance in an Underdamped System with Pinning Potential for Weak Signal Detection.

    Science.gov (United States)

    Zhang, Haibin; He, Qingbo; Kong, Fanrang

    2015-08-28

    Stochastic resonance (SR) has been proved to be an effective approach for weak sensor signal detection. This study presents a new weak signal detection method based on a SR in an underdamped system, which consists of a pinning potential model. The model was firstly discovered from magnetic domain wall (DW) in ferromagnetic strips. We analyze the principle of the proposed underdamped pinning SR (UPSR) system, the detailed numerical simulation and system performance. We also propose the strategy of selecting the proper damping factor and other system parameters to match a weak signal, input noise and to generate the highest output signal-to-noise ratio (SNR). Finally, we have verified its effectiveness with both simulated and experimental input signals. Results indicate that the UPSR performs better in weak signal detection than the conventional SR (CSR) with merits of higher output SNR, better anti-noise and frequency response capability. Besides, the system can be designed accurately and efficiently owing to the sensibility of parameters and potential diversity. The features also weaken the limitation of small parameters on SR system.

  6. Bridging micro to macroscale fracture properties in highly heterogeneous brittle solids: weak pinning versus fingering

    Science.gov (United States)

    Vasoya, Manish; Lazarus, Véronique; Ponson, Laurent

    2016-10-01

    The effect of strong toughness heterogeneities on the macroscopic failure properties of brittle solids is investigated in the context of planar crack propagation. The basic mechanism at play is that the crack is locally slowed down or even trapped when encountering tougher material. The induced front deformation results in a selection of local toughness values that reflect at larger scale on the material resistance. To unravel this complexity and bridge micro to macroscale in failure of strongly heterogeneous media, we propose a homogenization procedure based on the introduction of two complementary macroscopic properties: An apparent toughness defined from the loading required to make the crack propagate and an effective fracture energy defined from the rate of energy released by unit area of crack advance. The relationship between these homogenized properties and the features of the local toughness map is computed using an iterative perturbation method. This approach is applied to a circular crack pinned by a periodic array of obstacles invariant in the radial direction, which gives rise to two distinct propagation regimes: A weak pinning regime where the crack maintains a stationary shape after reaching an equilibrium position and a fingering regime characterized by the continuous growth of localized regions of the fronts while the other parts remain trapped. Our approach successfully bridges micro to macroscopic failure properties in both cases and illustrates how small scale heterogeneities can drastically affect the overall failure response of brittle solids. On a broader perspective, we believe that our approach can be used as a powerful tool for the rational design of heterogeneous brittle solids and interfaces with tailored failure properties.

  7. Improved charge collection of the buried p-i-n a-Si:H radiation detectors

    International Nuclear Information System (INIS)

    Fujieda, I.; Cho, G.; Conti, M.; Drewery, J.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Street, R.A.

    1989-09-01

    Charge collection in hydrogenated amorphous silicon (a-Si:H) radiation detectors is improved for high LET particle detection by adding thin intrinsic layers to the usual p-i-n structure. This buried p-i-n structure enables us to apply higher bias and the electric field is enhanced. When irradiated by 5.8 MeV α particles, the 5.7 μm thick buried p-i-n detector with bias 300V gives a signal size of 60,000 electrons, compared to about 20,000 electrons with the simple p-i-n detectors. The improved charge collection in the new structure is discussed. The capability of tailoring the field profile by doping a-Si:H opens a way to some interesting device structures. 17 refs., 7 figs

  8. Evidence for collective {delta}T{sub c} pinning in superconducting (K, Ba)BiO{sub 3} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Harneit, W [Centre National de la Recherche Scientifique (CNRS), 38 -Grenoble (France). Lab. d` Etudes des Proprietes Electroniques des Solides; Klein, T [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France). Lab. d` Etudes des Proprietes Electroniques des Solides; Baril, L [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France). Lab. d` Etudes des Proprietes Electroniques des Solides; Escribe-Filippini, C [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France). Lab. d` Etudes des Proprietes Electroniques des Solides

    1996-10-10

    The nature of pinning has been investigated in the three-dimensional high-T{sub c} superconductor (K, Ba)BiO{sub 3}. We show that the magnetic-field dependence of the critical current deduced from pulsed-field magnetization measurements can be well described by the collective-pinning theory on a large temperature range 0.06collective-pinning length L{sub c} is in excellent agreement with a model of flux pinning induced by spatial fluctuations of the critical temperature ({delta}T{sub c} pinning model). (orig.).

  9. Internal friction and dislocation collective pinning in disordered quenched solid solutions

    Science.gov (United States)

    D'Anna, G.; Benoit, W.; Vinokur, V. M.

    1997-12-01

    We introduce the collective pinning of dislocations in disordered quenched solid solutions and calculate the macroscopic mechanical response to a small dc or ac applied stress. This work is a generalization of the Granato-Lücke string model, able to describe self-consistently short and long range dislocation motion. Under dc applied stress the long distance dislocation creep has at the microscopic level avalanche features, which result in a macroscopic nonlinear "glassy" velocity-stress characteristic. Under ac conditions the model predicts, in addition to the anelastic internal friction relaxation in the high frequency regime, a linear internal friction background which remains amplitude-independent down to a crossover frequency to a strongly nonlinear internal friction regime.

  10. Computer simulation of vortex pinning in type II superconductors. II. Random point pins

    International Nuclear Information System (INIS)

    Brandt, E.H.

    1983-01-01

    Pinning of vortices in a type II superconductor by randomly positioned identical point pins is simulated using the two-dimensional method described in a previous paper (Part I). The system is characterized by the vortex and pin numbers (N/sub v/, N/sub p/), the vortex and pin interaction ranges (R/sub v/, R/sub p/), and the amplitude of the pin potential A/sub p/. The computation is performed for many cases: dilute or dense, sharp or soft, attractive or repulsive, weak or strong pins, and ideal or amorphous vortex lattice. The total pinning force F as a function of the mean vortex displacment X increases first linearly (over a distance usually much smaller than the vortex spacing and than R/sub p/) and then saturates, fluctuating about its averaging F-bar. We interpret F-bar as the maximum pinning force j/sub c/B of a large specimen. For weak pins the prediction of Larkin and Ovchinnikov for two-dimensional collective pinning is confirmed: F-bar = const. iW/R/sub p/c 66 , where W-bar is the mean square pinning force and c 66 is the shear modulus of the vortex lattice. If the initial vortex lattice is chosen highly defective (''amorphous'') the constant is 1.3--3 times larger than for the ideal triangular lattice. This finding may explain the often observed ''history effect.'' The function F-bar(A/sub p/) exhibits a jump, which for dilute, sharp, attractive pins occurs close to the ''threshold value'' predicted for isolated pins by Labusch. This jump reflects the onset of plastic deformation of the vortex lattice, and in some cases of vortex trapping, but is not a genuine threshold

  11. Collective-pinning theory and the observed vortex dynamics in RBa2Cu3O7-δ crystals

    International Nuclear Information System (INIS)

    Perkins, G.K.; Caplin, A.D.

    1996-01-01

    We establish a framework for the analysis of magnetization data on high-temperature superconductor crystals that allows direct comparison with vortex-pinning theory. When the magnetization loops exhibit scaling behavior, as they do over a large part of the B-T plane for RBa 2 Cu 3 O 7-δ crystals, the effective pinning energy U eff has to contain power-law field dependences for the characteristic energy and current scales U 0 and J 0 ; these power-law exponents can be obtained directly from the data. Many regimes of collective-pinning (CP) theory do predict such power laws, but none yield exponents in agreement with those that are measured. The discrepancy appears to arise because U 0 is observed to decrease with B, in contrast to the CP predictions. copyright 1996 The American Physical Society

  12. Individual chaos implies collective chaos for weakly mixing discrete dynamical systems

    International Nuclear Information System (INIS)

    Liao Gongfu; Ma Xianfeng; Wang Lidong

    2007-01-01

    Let X be a metric space (X,f) a discrete dynamical system, where f:X->X is a continuous function. Let f-bar denote the natural extension of f to the space of all non-empty compact subsets of X endowed with Hausdorff metric induced by d. In this paper we investigate some dynamical properties of f and f-bar . It is proved that f is weakly mixing (mixing) if and only if f-bar is weakly mixing (mixing, respectively). From this, we deduce that weak-mixing of f implies transitivity of f-bar , further, if f is mixing or weakly mixing, then chaoticity of f (individual chaos) implies chaoticity of f-bar (collective chaos) and if X is a closed interval then f-bar is chaotic (in the sense of Devaney) if and only if f is weakly mixing

  13. Ion-collecting sphere in a stationary, weakly magnetized plasma with finite shielding length

    International Nuclear Information System (INIS)

    Patacchini, Leonardo; Hutchinson, Ian H

    2007-01-01

    Collisionless ion collection by a negatively biased stationary spherical probe in a finite shielding length plasma is investigated using the Particle in Cell code SCEPTIC, in the presence of a weak magnetic field B. The overall effect of the magnetic field is to reduce the ion current, linearly in |B| for weak enough fields, with a slope steepness increasing with the electron Debye length. The angular current distribution and space-charge buildup strongly depend on the focusing properties of the probe, hence on its potential and the plasma shielding length. In particular, it is found that the concavity of the ion collection flux distribution can reverse sign when the electron Debye length is comparable to or larger than the probe radius (λ De ∼> r p ), provided the ion temperature is much lower than the probe bias (T i p )

  14. Pin care

    Science.gov (United States)

    ... Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Pin care URL of this page: //medlineplus.gov/ency/patientinstructions/000481.htm Pin care To use the sharing features on this page, please enable JavaScript. Broken bones can be fixed in surgery with metal ...

  15. Improved pinning regime by energetic ions using reduction of pinning potential

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy; Gandini, Alberto; Sawh, Ravi-Persad; Parks, Drew; Mayes, Bill

    2003-05-15

    When ion damage is used to create pinning centers, full columnar pinning centers provide the largest pinning potential, U{sub pin}, but not the greatest J{sub c} or pinned field, B{sub pin}. Some of the characteristics of columnar defects which limit J{sub c} and B{sub pin} are discussed, including reduction of percolation path, and the need for a larger number of columns of damage, for pinning, than are usually estimated. It is concluded that columnar pinning centers are limited to B{sub pin}<4 T, and also severely reduce J{sub c}. Evidence is reviewed that aligned damage, or broken-columnar pinning centers, described herein, can provide orders of magnitude higher J{sub c}, and higher pinned field, despite providing lower U{sub pin}. A pinning center morphology is discussed which utilizes multiple-in-line-damage (MILD). For, e.g., present day large grain HTS J{sub c}, obtainable by MILD pinning, is estimated to be of the order of 10{sup 6} A/cm{sup 2} at 77 K, even when crystal plane alignment and weak links are not improved. Pinned field is increased by over an order of magnitude. An experiment is proposed to confirm these observations, and to directly compare MILD to columnar pinning centers. It will also determine the optimum MILD structure. Other measurements of interest, made possible by the same data set, are described.

  16. Theory of activated glassy dynamics in randomly pinned fluids

    Science.gov (United States)

    Phan, Anh D.; Schweizer, Kenneth S.

    2018-02-01

    We generalize the force-level, microscopic, Nonlinear Langevin Equation (NLE) theory and its elastically collective generalization [elastically collective nonlinear Langevin equation (ECNLE) theory] of activated dynamics in bulk spherical particle liquids to address the influence of random particle pinning on structural relaxation. The simplest neutral confinement model is analyzed for hard spheres where there is no change of the equilibrium pair structure upon particle pinning. As the pinned fraction grows, cage scale dynamical constraints are intensified in a manner that increases with density. This results in the mobile particles becoming more transiently localized, with increases of the jump distance, cage scale barrier, and NLE theory mean hopping time; subtle changes of the dynamic shear modulus are predicted. The results are contrasted with recent simulations. Similarities in relaxation behavior are identified in the dynamic precursor regime, including a roughly exponential, or weakly supra-exponential, growth of the alpha time with pinning fraction and a reduction of dynamic fragility. However, the increase of the alpha time with pinning predicted by the local NLE theory is too small and severely so at very high volume fractions. The strong deviations are argued to be due to the longer range collective elasticity aspect of the problem which is expected to be modified by random pinning in a complex manner. A qualitative physical scenario is offered for how the three distinct aspects that quantify the elastic barrier may change with pinning. ECNLE theory calculations of the alpha time are then presented based on the simplest effective-medium-like treatment for how random pinning modifies the elastic barrier. The results appear to be consistent with most, but not all, trends seen in recent simulations. Key open problems are discussed with regard to both theory and simulation.

  17. Collective dynamics of populations of weakly correlated filaments of incoherent white light

    International Nuclear Information System (INIS)

    Guo, Jinxin; Sheridan, John T; Saravanamuttu, Kalaichelvi

    2013-01-01

    We examined the dynamics of two populations of self-trapped filaments of spatially and temporally incoherent white light. The populations consisted of (i) independent filaments generated through self-trapping of incandescent speckles, and (ii) co-dependent filaments created through modulation instability of a broad incandescent beam. Both filament populations were positionally stable in conditions where individual pairs of self-trapped beams interact strongly. Both also acquired significantly broad intensity distributions, which were independent of their parent optical fields; a small but persistent number of high-intensity filaments was identified in both cases. These studies provide accessible routes to weakly correlated ensembles, insight into their collective behaviour such as self-stabilization and self-selected intensity distributions, and reveal intriguing similarities between the dynamics of two populations of different origins. (paper)

  18. Solution of weakly compressible isothermal flow in landfill gas collection networks

    Energy Technology Data Exchange (ETDEWEB)

    Nec, Y [Thompson Rivers University, Kamloops, British Columbia (Canada); Huculak, G, E-mail: cranberryana@gmail.com, E-mail: greg@gnhconsulting.ca [GNH Consulting, Delta, British Columbia (Canada)

    2017-12-15

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein. (paper)

  19. Solution of weakly compressible isothermal flow in landfill gas collection networks

    Science.gov (United States)

    Nec, Y.; Huculak, G.

    2017-12-01

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy-Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein.

  20. Solution of weakly compressible isothermal flow in landfill gas collection networks

    International Nuclear Information System (INIS)

    Nec, Y; Huculak, G

    2017-01-01

    Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy–Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein. (paper)

  1. Kinetic Analysis of Weakly ionized Plasmas in presence of collecting walls

    Science.gov (United States)

    Gonzalez, J.; Donoso, J. M.

    2018-02-01

    Description of plasmas in contact with a wall able to collecting or emitting charged particles is a research topic of great importance. This situation arises in a great variety of phenomena such as the characterization of plasmas by means of electric probes, in the surface treatment of materials and in the service-life of coatings in electric thrusters. In particular, in this work we devote attention to the dynamics of an argon weakly ionized plasma in the presence of a collecting wall. It is proposed a kinetic model in a 1D1V planar phase-space geometry. The model accounts for the electric field coupled to the system by solving the associated Poisson’s equation. To solve numerically the resulting non-linear system of equations, the Propagator Integral Method is used in conjunction with a slabbing method. On each interrelating plasma slab the integral advancing scheme operates in velocity space, in such a way that the all the species dynamics dominating the system evolution are kinetically described.

  2. Happy Pinning

    DEFF Research Database (Denmark)

    Fausing, Bent

    2012-01-01

    This is about Pinterest, but with a different approach than usual to social networks. Pinterest is an image site par excellence. The images are as Windows that open outwards and also lets us look inwards and displays the soul and heart, the unintentional or pre-conscious desires. Happy Pinning!...

  3. Pinning in nonmagnetic borocarbides

    International Nuclear Information System (INIS)

    Zholobenko, A.N.; Mikitik, G.P.; Fil, V.D.; Kim, J.D.; Lee, S.I.

    2005-01-01

    The field dependences of the Labush parameter in nonmagnetic borocarbides are measured by the method which does not require the free flux flow regime. The anticipated critical current densities are estimated. These values are by two orders of magnitude higher than those measured 'directly' in transport (magnetic) experiments. The giant peak-effect in the field dependences of the Labush parameter is revealed in the Y-based borocarbides. Its behavior is well approximated by the collective pinning theory

  4. Improved pinning by multiple in-line damage

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Sawh, Ravi-Persad [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Gandini, Alberto [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Parks, Drew [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States)

    2005-02-01

    Columnar pinning centres provide the largest pinning potential, U{sub pin}, but not the greatest J{sub c} or pinnable field, B{sub pin}. Characteristics of ion-generated columnar defects which limit J{sub c} and B{sub pin} are discussed, including reduction of the percolation path, and the need for a larger number of columns of damage, for pinning, than are usually estimated. It is concluded that columnar pinning centres limit B{sub pin} to less than 4 T, and also severely reduce J{sub c}. The goal of maximizing U{sub pin}, via columnar centres, appears to have obscured a more rewarding approach and resulted in neglect of a large regime of ion interactions. Evidence is reviewed that multiple in-line damage (MILD), described herein, can provide orders of magnitude higher J{sub c} and B{sub pin}, despite providing lower U{sub pin}. The MILD pinning centre morphology is discussed, and it is estimated that for present-day large grain high T{sub c} superconductors, a J{sub c} value of {approx}10{sup 6}Acm{sup -2} is obtainable at 77 K, even when crystal plane alignment and weak links are not improved. In addition, the pinned field is increased by over an order of magnitude. An experiment is proposed to confirm these calculations, directly compare MILD pinning to continuous columnar pinning, and determine the optimum MILD structure. Applications of MILD pinning are discussed.

  5. An extended collection length model for the description of keV-electron induced degradation and thermal recovery of p-i-n solar cells

    International Nuclear Information System (INIS)

    Schneider, U.; Schroder, B.

    1990-01-01

    The results of keV-electron degradation and annealing experiments obtained on a-Si:H based p-i-n solar cells are interpretated under inclusion of models developed earlier for the degradation of a-Si:H films and are placed in the framework of an extended collection length model. The strong degradation of the cell parameters j sc and FF due to considerable keV-electron irradiation can be explained quantitatively. This enables a crucial test of the validity of the mathematical models for the keV-electron induced effects developed so far. Furthermore the results of a detailed investigation of the thermal recovery of electron-degraded solar cells can be cleared up consistently. Some unresolved issues are discussed, and experiments to resolve these questions are proposed

  6. Collective Dynamics and Strong Pinning near the Onset of Charge Order in La1.48Nd0.4Sr0.12CuO4

    Science.gov (United States)

    Baity, P. G.; Sasagawa, T.; Popović, Dragana

    2018-04-01

    The dynamics of charge-ordered states is one of the key issues in underdoped cuprate high-temperature superconductors, but static short-range charge-order (CO) domains have been detected in almost all cuprates. We probe the dynamics across the CO (and structural) transition in La1.48Nd0.4Sr0.12CuO4 by measuring nonequilibrium charge transport, or resistance R as the system responds to a change in temperature and to an applied magnetic field. We find evidence for metastable states, collective behavior, and criticality. The collective dynamics in the critical regime indicates strong pinning by disorder. Surprisingly, nonequilibrium effects, such as avalanches in R , are revealed only when the critical region is approached from the charge-ordered phase. Our results on La1.48Nd0.4Sr0.12CuO4 provide the long-sought evidence for the fluctuating order across the CO transition, and also set important constraints on theories of dynamic stripes.

  7. Combinatoric Models of Information Retrieval Ranking Methods and Performance Measures for Weakly-Ordered Document Collections

    Science.gov (United States)

    Church, Lewis

    2010-01-01

    This dissertation answers three research questions: (1) What are the characteristics of a combinatoric measure, based on the Average Search Length (ASL), that performs the same as a probabilistic version of the ASL?; (2) Does the combinatoric ASL measure produce the same performance result as the one that is obtained by ranking a collection of…

  8. Internal fuel pin oxidizer

    International Nuclear Information System (INIS)

    Andrews, M.G.

    1978-01-01

    A nuclear fuel pin has positioned within it material which will decompose to release an oxidizing agent which will react with the cladding of the pin and form a protective oxide film on the internal surface of the cladding

  9. Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells

    Directory of Open Access Journals (Sweden)

    Jooyeok Seo

    2017-02-01

    Full Text Available We report the effect of weak base addition to acidic polymer hole-collecting layers in normal-type polymer:fullerene solar cells. Varying amounts of the weak base aniline (AN were added to solutions of poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS. The acidity of the aniline-added PEDOT:PSS solutions gradually decreased from pH = 1.74 (AN = 0 mol% to pH = 4.24 (AN = 1.8 mol %. The electrical conductivity of the PEDOT:PSS-AN films did not change much with the pH value, while the ratio of conductivity between out-of-plane and in-plane directions was dependent on the pH of solutions. The highest power conversion efficiency (PCE was obtained at pH = 2.52, even though all devices with the PEDOT:PSS-AN layers exhibited better PCE than those with the pristine PEDOT:PSS layers. Atomic force microscopy investigation revealed that the size of PEDOT:PSS domains became smaller as the pH increased. The stability test for 100 h illumination under one sun condition disclosed that the PCE decay was relatively slower for the devices with the PEDOT:PSS-AN layers than for those with pristine PEDOT:PSS layers.

  10. Enhanced collective focusing of intense neutralized ion beam pulses in the presence of weak solenoidal magnetic fields

    International Nuclear Information System (INIS)

    Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; Startsev, Edward A.

    2012-01-01

    The design of ion drivers for warm dense matter and high energy density physics applications and heavy ion fusion involves transverse focusing and longitudinal compression of intense ion beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the ion bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various ion driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-focusing force can be significantly enhanced if a weak (B ∼ 100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-focusing has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasma electrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse focusing can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final focus solenoid is used for this purpose. In the present analysis we propose that the tight final focus in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the ion beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced focusing is provided by the collective electron dynamics strongly affected by a weak applied magnetic field.

  11. MICROCONTROLLER PIN CONFIGURATION TOOL

    OpenAIRE

    Bhaskar Joshi; F. Mohammed Rizwan; Dr. Rajashree Shettar

    2012-01-01

    Configuring the micro controller with large number of pins is tedious. Latest Infine on microcontroller contains more than 200 pins and each pin has classes of signals. Therefore the complexity of the microcontroller is growing. It evolves looking into thousands of pages of user manual. For a user it will take days to configure the microcontroller with the peripherals. We need an automated tool to configure the microcontroller so that the user can configure the microcontroller without having ...

  12. PINS Spectrum Identification Guide

    Energy Technology Data Exchange (ETDEWEB)

    A.J. Caffrey

    2012-03-01

    The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.

  13. Fuel pin transfer tool

    International Nuclear Information System (INIS)

    Patenaude, R. S.

    1985-01-01

    A fuel pin transfer tool has a latching device of the collet type attached to a first member movable vertically through a long work stroke enabling a fuel pin in an under water assembly to be engaged and withdrawn therefrom or placed therein and released. The latching device has a collet provided with a plurality of resilient fingers having cam portions normally spaced apart to receive the upper end of a fuel pin between them and a second member, movable vertically through a short stroke relative to the first member is provided with cam portions engageable with those of the fingers and is yieldably and resiliently held in a raised position in which its cam portions engage those of the fingers and force the fingers into their pin-gripping positions. When a predetermined force is applied to the second member, it is so moved that its cam portions are disengaged from the cam portions of the fingers permitting the latter to move into their normal relationship in which a gripped pin is released or another pin received but with their pin-gripping relationship positively re-established and maintained once the force on the tubular member is lessened. Movement of the first member in either direction and movement of the second member into its raised position is attended by forces inadequate to affect the integrity of fuel pin cladding. That force is applied in the preferred embodiment, by a power operated actuator which is within the upper portion of a housing and, in the preferred embodiment, carried by the long stroke member but always in the upper housing portion which is of a material sufficiently translucent to enable the actuator to be observed throughout the work stroke and is sufficiently light in weight to prevent the tool from being top heavy

  14. Flux Pinning in Superconductors

    CERN Document Server

    Matsushita, Teruo

    2007-01-01

    The book covers the flux pinning mechanisms and properties and the electromagnetic phenomena caused by the flux pinning common for metallic, high-Tc and MgB2 superconductors. The condensation energy interaction known for normal precipitates or grain boundaries and the kinetic energy interaction proposed for artificial Nb pins in Nb-Ti, etc., are introduced for the pinning mechanism. Summation theories to derive the critical current density are discussed in detail. Irreversible magnetization and AC loss caused by the flux pinning are also discussed. The loss originally stems from the ohmic dissipation of normal electrons in the normal core driven by the electric field induced by the flux motion. The readers will learn why the resultant loss is of hysteresis type in spite of such mechanism. The influence of the flux pinning on the vortex phase diagram in high Tc superconductors is discussed, and the dependencies of the irreversibility field are also described on other quantities such as anisotropy of supercondu...

  15. Vortex pinning landscape in MOD-TFA YBCO nanostroctured films

    Science.gov (United States)

    Gutierrez, J.; Puig, T.; Pomar, A.; Obradors, X.

    2008-03-01

    A methodology of general validity to study vortex pinning in YBCO based on Jc transport measurements is described. It permits to identify, separate and quantify three basic vortex pinning contributions associated to anisotropic-strong, isotropic-strong and isotropic-weak pinning centers. Thereof, the corresponding vortex pinning phase diagrams are built up. This methodology is applied to the new solution-derived YBCO nanostructured films, including controlled interfacial pinning by the growth of nanostructured templates by means of self-assembled processes [1] and YBCO-BaZrO3 nanocomposites prepared by modified solution precursors. The application of the methodology and comparison with a standard solution-derived YBCO film [2], enables us to identify the nature and the effect of the additional pinning centers induced. The nanostructured templates films show c-axis pinning strongly increased, controlling most of the pinning phase diagram. On the other hand, the nanocomposites have achieved so far, the highest pinning properties in HTc-superconductors [3], being the isotropic-strong defects contribution the origin of their unique properties. [1] M. Gibert et al, Adv. Mat. vol 19, p. 3937 (2007) [2] Puig.T et al, SuST EUCAS 2007 (to be published) [3] J. Gutierrez et al, Nat. Mat. vol. 6, p. 367 (2007) * Work supported by HIPERCHEM, NANOARTIS and MAT2005-02047

  16. Instability of collective strong-interaction phenomena in hadron production as a possible origin of the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1975-12-01

    A systematic calculus of long-range Regge cut effects in multiparticle production is constructed in the form of an infrared-divergent stochastic field theory. Total cross sections and two-body overlap integrals in such a theory may depend very sensitively upon internal quantum-numbers of incident particles, resulting in a strong symmetry breaking at ultra-high energies. Such symmetry violations will influence low energy processes through dispersion relations, and a bootstrap of weak interactions becomes possible. A rough analytic estimate of the scale of thresholds for such effects yields a BCS-type gap equation, which expresses the scale of weak and electromagnetic couplings in terms of purely strong-interaction parameters

  17. A pinning puzzle: two similar, non-superconducting chemical deposits in YBCO-one pins, the other does not

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad; Weinstein, Roy; Gandini, Alberto; Skorpenske, Harley; Parks, Drew, E-mail: Weinstein@uh.ed [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Texas Center for Superconductivity at UH, University of Houston, Houston, TX 77204-5002 (United States)

    2009-09-15

    The pinning effects of two kinds of U-rich deposits in YBCO (YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}) are compared. One is a five-element compound, (U{sub 0.6}Pt{sub 0.4})YBa{sub 2}O{sub 6}, which is a paramagnetic double perovskite which forms as profuse stable nanosize deposits, and pins very well. The other is a four-element compound, (U{sub 0.4}Y{sub 0.6})BaO{sub 3}, which is a ferromagnetic single perovskite which forms as profuse stable nanosize deposits and pins very weakly or not at all. The pinning comparison is done with nearly equal deposit sizes and number of deposits per unit volume for the two compounds. Evidence for the pinning capability, chemical makeup, x-ray diffraction signature, and magnetic properties of the two compounds is reported.

  18. PINS-3X Operations

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury

    2013-09-01

    Idaho National Laboratory’s (INL’s) Portable Isotopic Neutron Spectroscopy System (PINS) non-intrusively identifies the chemical fill of munitions and sealed containers. The PINS-3X variant of the system is used to identify explosives and uses a deuterium-tritium (DT) electronic neutron generator (ENG) as the neutron source. Use of the system, including possession and use of the neutron generator and shipment of the system components requires compliance with a number of regulations. This report outlines some of these requirements as well as some of the requirements in using the system outside of INL.

  19. Pinning control of complex networked systems synchronization, consensus and flocking of networked systems via pinning

    CERN Document Server

    Su, Housheng

    2013-01-01

    Synchronization, consensus and flocking are ubiquitous requirements in networked systems. Pinning Control of Complex Networked Systems investigates these requirements by using the pinning control strategy, which aims to control the whole dynamical network with huge numbers of nodes by imposing controllers for only a fraction of the nodes. As the direct control of every node in a dynamical network with huge numbers of nodes might be impossible or unnecessary, it’s then very important to use the pinning control strategy for the synchronization of complex dynamical networks. The research on pinning control strategy in consensus and flocking of multi-agent systems can not only help us to better understand the mechanisms of natural collective phenomena, but also benefit applications in mobile sensor/robot networks. This book offers a valuable resource for researchers and engineers working in the fields of control theory and control engineering.   Housheng Su is an Associate Professor at the Department of Contro...

  20. Pinning Down versus Density

    OpenAIRE

    Juhász, István; Soukup, Lajos; Szentmiklóssy, Zoltán

    2015-01-01

    The pinning down number $ {pd}(X)$ of a topological space $X$ is the smallest cardinal $\\kappa$ such that for any neighborhood assignment $U:X\\to \\tau_X$ there is a set $A\\in [X]^\\kappa$ with $A\\cap U(x)\

  1. Pin clad strains in Phenix

    International Nuclear Information System (INIS)

    Languille, A.

    1979-07-01

    The Phenix reactor has operated for 4 years in a satisfactory manner. The first 2 sub-assembly loadings contained pins clad in solution treated 316. The principal pin strains are: diametral strain (swelling and irradiation creep), ovality and spiral bending of the pin (interaction of wire and pin cluster and wrapper). A pin cluster irradiated to a dose of 80 dpa F reached a pin diameter strain of 5%. This strain is principally due to swelling (low fission gas pressure). The principal parameters governing the swelling are instantaneous dose, time and temperature for a given type of pin cladding. Other types of steel are or will be irradiated in Phenix. In particular, cold-worked titanium stabilised 316 steel should contribute towards a reduction in the pin clad strains and increase the target burn-up in this reactor. (author)

  2. Dynamics of two-dimensional vortex system in a strong square pinning array at the second matching field

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Qing-Bao [Department of Physics, Lishui University, Lishui 323000 (China); Luo, Meng-Bo, E-mail: Luomengbo@zju.edu.cn [Department of Physics, Zhejiang University, Hangzhou 310027 (China)

    2013-10-30

    We study the dynamics of a two-dimensional vortex system in a strong square pinning array at the second matching field. Two kinds of depinning behaviors, a continuous depinning transition at weak pinning and a discontinuous one at strong pinning, are found. We show that the two different kinds of vortex depinning transitions can be identified in transport as a function of the pinning strength and temperature. Moreover, interstitial vortex state can be probed from the transport properties of vortices.

  3. Radon measurements with a PIN photodiode

    International Nuclear Information System (INIS)

    Martin-Martin, A.; Gutierrez-Villanueva, J.L.; Munoz, J.M.; Garcia-Talavera, M.; Adamiec, G.; Iniguez, M.P.

    2006-01-01

    Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by 218 Po and 214 Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations

  4. Spin effects in the weak interaction

    International Nuclear Information System (INIS)

    Freedman, S.J.; Chicago Univ., IL; Chicago Univ., IL

    1990-01-01

    Modern experiments investigating the beta decay of the neutron and light nuclei are still providing important constraints on the theory of the weak interaction. Beta decay experiments are yielding more precise values for allowed and induced weak coupling constants and putting constraints on possible extensions to the standard electroweak model. Here we emphasize the implications of recent experiments to pin down the strengths of the weak vector and axial vector couplings of the nucleon

  5. Dependence of J c on pinning center morphology: An explanation of record J c observed for discontinuous columnar pinning of vortices

    International Nuclear Information System (INIS)

    Weinstein, R.; Gandini, A.; Parks, D.; Sawh, R.; Mayes, B.

    2006-01-01

    An experimental study of defects caused by ion irradiation has proven that very discontinuous multiple-in-line-damage results in much higher J c than continuous columnar pinning centers. This is contrary to conventional wisdom. We develop a first approximation to a theory relating J c to the morphology of pinning centers. Qualitative agreement with experiment is achieved. Conclusions indicate the relative importance of pinning potential, percolation, and critical temperature for various morphologies. Results suggest the leading importance of pinning, compared to texture, weak links and oxygenation in achievement of the goal of high J c especially in large grain HTS

  6. Nuclear fuel pin

    International Nuclear Information System (INIS)

    Hartley, Kenneth; Moulding, T.L.J.; Rostron, Norman.

    1979-01-01

    Fuel pin for use in fast breeder nuclear reactors containing fissile and fertile areas of which the fissile and fertile materials do not mix. The fissile material takes the shape of large and small diameter microspheres (the small diameter microspheres can pass through the interstices between the large microspheres). The barrier layers being composed of microspheres with a diameter situated between those of the large and small microspheres ensure that the materials do not mix [fr

  7. Investigation of pinning in MgB2 superconductors

    International Nuclear Information System (INIS)

    Mohammad, S.; Reissner, M.; Steiner, W.; Bauer, E.; Giovannini, M.

    2006-01-01

    Full text: The pinning behaviour of bulk MgB 2 superconductors is peculiar in many respects. Pinning seems to be stronger than in classical high T C materials and there seems to be no weak link problem in these compounds, giving hope to produce bulk samples and wires with current densities appropriate for technical applications. But, although many studies concerning the pinning behaviour in this compound appeared in recent years, the results are still contradictory. In the present work we present results of an investigation of the pinning behaviour by magnetic relaxation measurements of three MgB 2 samples: a pure one, a sample with 8 at% Al substitution and a sample with 10 wt% of SiC admixture. A comparison of different analyses methods is given. (author)

  8. Incommensurate pinning mechanism in KCP

    International Nuclear Information System (INIS)

    Apostol, M.; Baldea, I.

    1984-07-01

    A new pinning mechanism (termed incommensurate) is put forward for K 2 Pt(CN) 4 Brsub(0.3)x3.2H 2 O(KCP) based on the Q-quasi-modulated distribution of the bromine anions (Br-bar) along the chain axis (Q/2 being the Fermi momentum reduced to the first Brillouin zone). The different origins of the direct current (d.c.) thermally-activated gap and optical gap are thereby explained. The spectrum of the collective excitations (amplitudons and phasons) and the dielectric function are calculated for the charge density wave (CDW) state. Fair agreement is obtained with the optical and neutron scattering data. (author)

  9. Effects of magnetizing on flux pinning force for sintered YBCO superconductor

    International Nuclear Information System (INIS)

    Ding, S.Y.; Yan, J.L.; Yu, Z.; Shi, K.X.; Tong, H.W.; Qiu, L.

    1989-01-01

    It is shown that magnitude and course of magnetizing field influence magnetization and transport current. Effective flux pinning force density with two types is extracted by an iterative procedure based on the critical state equation. One of the types is attributed to the weak links and the other is considered to be resulted from the intragrain flux pinning centers

  10. Comparison of thermomagnetic history effects in weakly pinned ...

    Indian Academy of Sciences (India)

    1Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, ... systems, where the characteristic internal structures span the entire PE regime. .... financial support in the form of Kanwal Rekhi Career Development Award.

  11. Weak currents

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1976-01-01

    A survey of the fundamental ideas on weak currents such as CVC and PCAC and a presentation of the Cabibbo current and the neutral weak currents according to the Salam-Weinberg model and the Glashow-Iliopoulos-Miami model are given [fr

  12. Weak decays

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  13. Development of 3D pseudo pin-by-pin calculation methodology in ANC

    International Nuclear Information System (INIS)

    Zhang, B.; Mayhue, L.; Huria, H.; Ivanov, B.

    2012-01-01

    Advanced cores and fuel assembly designs have been developed to improve operational flexibility, economic performance and further enhance safety features of nuclear power plants. The simulation of these new designs, along with strong heterogeneous fuel loading, have brought new challenges to the reactor physics methodologies currently employed in the industrial codes for core analyses. Control rod insertion during normal operation is one operational feature in the AP1000 R plant of Westinghouse next generation Pressurized Water Reactor (PWR) design. This design improves its operational flexibility and efficiency but significantly challenges the conventional reactor physics methods, especially in pin power calculations. The mixture loading of fuel assemblies with significant neutron spectrums causes a strong interaction between different fuel assembly types that is not fully captured with the current core design codes. To overcome the weaknesses of the conventional methods, Westinghouse has developed a state-of-the-art 3D Pin-by-Pin Calculation Methodology (P3C) and successfully implemented in the Westinghouse core design code ANC. The new methodology has been qualified and licensed for pin power prediction. The 3D P3C methodology along with its application and validation will be discussed in the paper. (authors)

  14. Weak interactions

    International Nuclear Information System (INIS)

    Ogava, S.; Savada, S.; Nakagava, M.

    1983-01-01

    The problem of the use of weak interaction laws to study models of elementary particles is discussed. The most typical examples of weak interaction is beta-decay of nucleons and muons. Beta-interaction is presented by quark currents in the form of universal interaction of the V-A type. Universality of weak interactions is well confirmed using as examples e- and μ-channels of pion decay. Hypothesis on partial preservation of axial current is applicable to the analysis of processes with pion participation. In the framework of the model with four flavours lepton decays of hadrons are considered. Weak interaction without lepton participation are also considered. Properties of neutral currents are described briefly

  15. Weak interactions

    International Nuclear Information System (INIS)

    Chanda, R.

    1981-01-01

    The theoretical and experimental evidences to form a basis for Lagrangian Quantum field theory for Weak Interactions are discussed. In this context, gauge invariance aspects of such interactions are showed. (L.C.) [pt

  16. Transformation of Helicopter PinS Procedures for Airplanes

    Directory of Open Access Journals (Sweden)

    Jakub Kraus

    2013-09-01

    Full Text Available This article deals with the possibility to use existing helicopter Point in Space procedures with minor changes for airplanes. The basis is to find parts of PinS procedures that need to be changed, suggest these changes, and then determine whether the revised procedures could be usable and could bring the benefits for airplane operations.

  17. Pinning, de-pinning and re-pinning of a slowly varying rivulet

    KAUST Repository

    Paterson, C.; Wilson, S.K.; Duffy, B.R.

    2013-01-01

    The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

  18. Pinning, de-pinning and re-pinning of a slowly varying rivulet

    KAUST Repository

    Paterson, C.

    2013-09-01

    The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

  19. Vortex pinning and creep experiments

    International Nuclear Information System (INIS)

    Kes, P.H.

    1991-01-01

    A brief review of basic flux-pinning and flux-creep ingredients and a selection of experimental results on high-temperature-superconductivity compounds is presented. Emphasis is put on recent results and on those properties which are central to the emerging understanding of the flux-pinning and flux-creep mechanisms of these fascinating materials

  20. Spatial chaotic behavior of vortices in type-II superconductors with different pinning strength

    International Nuclear Information System (INIS)

    Lin, H.-T.; Pan, M.; Cheng, C.H.; Cui, Y.J.; Zhao, Y.

    2008-01-01

    Spatial chaotic character in systems where defects are arranged in periodic arrays has been investigated by computer simulation. Due to the high nonlinearity of the vortex-defect interaction, arrangement of the vortices in a periodic pinning array can be chaotic (glassy), depending on the vortex-defect interaction state and vortex-vortex interaction. Two types of disordered vortex states in the system are observed. The type-I disorder arises from the intrinsically chaotic nature of the nonlinear system, existing when the pinning disorder is low and the pinning strength is weak. The type-II disordered state is related to the pinning disorder, which is dominating when both the pinning disorder and the pinning strength are strong

  1. Spatial chaotic behavior of vortices in type-II superconductors with different pinning strength

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.-T. [Faculty of Information Management, Cheng Shui University, Taiwan (China); Pan, M. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney (Australia); Cui, Y.J. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney (Australia)], E-mail: yzhao@swjtu.edu.cn

    2008-09-15

    Spatial chaotic character in systems where defects are arranged in periodic arrays has been investigated by computer simulation. Due to the high nonlinearity of the vortex-defect interaction, arrangement of the vortices in a periodic pinning array can be chaotic (glassy), depending on the vortex-defect interaction state and vortex-vortex interaction. Two types of disordered vortex states in the system are observed. The type-I disorder arises from the intrinsically chaotic nature of the nonlinear system, existing when the pinning disorder is low and the pinning strength is weak. The type-II disordered state is related to the pinning disorder, which is dominating when both the pinning disorder and the pinning strength are strong.

  2. Weak interactions

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1978-01-01

    Weak interactions are studied from a phenomenological point of view, by using a minimal number of theoretical hypotheses. Charged-current phenomenology, and then neutral-current phenomenology are discussed. This all is described in terms of a global SU(2) symmetry plus an electromagnetic correction. The intermediate-boson hypothesis is introduced and lower bounds on the range of the weak force are inferred. This phenomenology does not yet reconstruct all the predictions of the conventional SU(2)xU(1) gauge theory. To do that requires an additional assumption of restoration of SU(2) symmetry at asymptotic energies

  3. Automated fuel pin loading system

    Science.gov (United States)

    Christiansen, D.W.; Brown, W.F.; Steffen, J.M.

    An automated loading system for nuclear reactor fuel elements utilizes a gravity feed conveyor which permits individual fuel pins to roll along a constrained path perpendicular to their respective lengths. The individual lengths of fuel cladding are directed onto movable transports, where they are aligned coaxially with the axes of associated handling equipment at appropriate production stations. Each fuel pin can be be reciprocated axially and/or rotated about its axis as required during handling steps. The fuel pins are inerted as a batch prior to welding of end caps by one of two disclosed welding systems.

  4. Pinning down the axion

    International Nuclear Information System (INIS)

    Dabholkar, A.; Quashnock, J.M.

    1990-01-01

    Davis has argued that, without inflation, the decay of axionic strings is the primary source of axions. This implies a cosmological lower bound on the axion mass of 10 -5 to 10 -3 eV. In order to obtain a sharper bound it is essential to know the spectrum of emitted axions and the detailed motion of a global string strongly coupled to the axionic field. To this end, we obtain self-consistent, renormalized equations that describe the dynamics of a radiating global string interacting with its surrounding axionic field. We describe the numerical formalism for evolving string trajectories using these equations. From the numerical and analytical evidence we argue that, with appropriate renormalization, the motion of an interacting cosmic string loop can be well approximated by the motion of a free Nambu-Goto string. This implies a lower bound for the axion mass of 10 -3 eV. Together with the recent upper bound of 4x10 -4 eV from the supernova SN1987a, this marginally rules out the invisible axion, or at least pins down the axion mass to a very narrow window around 10 -3 eV. This still leaves open the window around 2 eV for hardronic axions, but in that case the axion is no longer a serious dark matter candidate. (orig.)

  5. Pinning Mechanisms in YBCO Tapes

    CERN Document Server

    Spera, Marcello; Ballarino, Amalia

    2015-01-01

    In this thesis work, a study on flux pinning mechanisms of commercial YBCO tapes is presented. This study has been performed via critical current characterization using transport (via direct I-V curves) and magnetization (via a Vibrating Sample Magnetometer) measurements. The latter ones turned out to be better concerning the comprehension of the pinning landscape of the provided samples, as a wider range of magnetic fields and temperatures is available for those measurements in the setup I used. The comparison of the experimental data with existing theoretical models allowed me to draw a picture of the pinning mechanisms underlying in each sample, and they turned out to be quite different one another. Moreover, for high-performance research tapes, another interesting feature has been found: the counterplay between the self-field critical current and the in-field one. Very well engineered artificial pinning structures limit the self-field critical current density due to the hi...

  6. Automated system for loading nuclear fuel pins

    International Nuclear Information System (INIS)

    Marshall, J.L.

    1983-10-01

    A completely automatic and remotely controlled fuel pin fabrication system is being designed by the Westinghouse Hanford Company. The Pin Operations System will produce fuel pins for the Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor Plant (CRBRP). The system will assemble fuel pin components into cladding tubes in a controlled environment. After fuel loading, the pins are filled with helium, the tag gas capsules are inserted, and the top end cap welded. Following welding, the pins are surveyed to assure they are free of contamination and then the pins are helium leak tested

  7. Weak relativity

    CERN Document Server

    Selleri, Franco

    2015-01-01

    Weak Relativity is an equivalent theory to Special Relativity according to Reichenbach’s definition, where the parameter epsilon equals to 0. It formulates a Neo-Lorentzian approach by replacing the Lorentz transformations with a new set named “Inertial Transformations”, thus explaining the Sagnac effect, the twin paradox and the trip from the future to the past in an easy and elegant way. The cosmic microwave background is suggested as a possible privileged reference system. Most importantly, being a theory based on experimental proofs, rather than mutual consensus, it offers a physical description of reality independent of the human observation.

  8. Vortex Avalanches with Periodic Arrays of Pinning Sites

    Science.gov (United States)

    Abbas, J.; Heckel, T.; Kakalios, J.

    2001-03-01

    Numerical simulations by Nori and co-workers of dynamical phase transitions for magnetic vortices in type II superconductors when the defects which act as pinning sites are arranged in a periodic array have found a dramatic non-linear relationship between vortex voltage and driving current.2,4 In order to experimentally test the predictions of these simulations, a macroscopic physical analog of an array of flux vortices in the presense of an ordered lattice of pinning sites has been constructed. This simple table-top experimental system consists of conventional household magnets, arranged in an ordered grid (serving as the lattice of fixed pinning centers). A plexiglass sheet is positioned above these fixed magnets, and another collection of magnets (representing the magnetic flux vortices), oriented so that they are attracted to the fixed magnets are placed on top of the sheet. The entire apparatus is then tilted to a given angle (the analog of the driving voltage) and the velocity of the avalanching magnets is recorded using the induced voltage in a pick-up coil. By varying the ratio of movable magnets to fixed pinning magnets, the filling fraction can be adjusted, as can the pinning strength, by adjusting the separation of the plexiglass sheet between the fixed and movable magnets. The velocity of the avalanching magnets as the filling fraction is varied displays a jamming transition, with a non-trivial dependence on the pinning strength of the lattice of fixed magnets below the sheet.

  9. Investigations of flow and temperature field development in bare and wire-wrapped reactor fuel pin bundles cooled by sodium

    International Nuclear Information System (INIS)

    Govindha Rasu, N.; Velusamy, K.; Sundararajan, T.; Chellapandi, P.

    2013-01-01

    Highlights: ► We study sodium flow and temperature development in fuel pin bundles. ► Pin diameter, number of pins, wire wrap and ligament gap are varied as parameters. ► Flow development is achieved within ∼30–40 hydraulic diameters. ► Thermal development is attained only for small pin diameter and less number of pins. ► Wire wrap and ligament gap strongly influence Nusselt number. - Abstract: Simultaneous development of liquid sodium flow and temperature fields in the heat generating pin bundles of reactor has been investigated. Development characteristics are seen to be strongly influenced by pin diameter, number of pins, helical wire-wrap, ligament gap between the last row of pins and hexcan wall and Reynolds number. Flow development is achieved within an axial length of ∼125 hydraulic diameters, for all the pin bundle configurations considered. But temperature development is attained only if the pin diameter is small or the number of pins is less. In the case of large pin diameter with more pins, temperature development could not be achieved even after a length of ∼1000 hydraulic diameters. The reason for this behavior is traced to be the weak communication among sub-channels in tightly packed bundles. It is seen that the pin Nusselt number decreases from center to periphery in a bundle. Also, if the ligament gap is narrow, the Nusselt number is large and more uniform. Flow development length is short if the Reynolds number is large and the converse is true for thermal development length. Helical wire-wrap shortens the thermal entry length and significantly enhances the global Nusselt number. But, its influence on hydrodynamic entry length is not significant

  10. Enhanced pinning in superconducting thin films with graded pinning landscapes

    Science.gov (United States)

    Motta, M.; Colauto, F.; Ortiz, W. A.; Fritzsche, J.; Cuppens, J.; Gillijns, W.; Moshchalkov, V. V.; Johansen, T. H.; Sanchez, A.; Silhanek, A. V.

    2013-05-01

    A graded distribution of antidots in superconducting a-Mo79Ge21 thin films has been investigated by magnetization and magneto-optical imaging measurements. The pinning landscape has maximum density at the sample border, decreasing linearly towards the center. Its overall performance is noticeably superior than that for a sample with uniformly distributed antidots: For high temperatures and low fields, the critical current is enhanced, whereas the region of thermomagnetic instabilities in the field-temperature diagram is significantly suppressed. These findings confirm the relevance of graded landscapes on the enhancement of pinning efficiency, as recently predicted by Misko and Nori [Phys. Rev. B 85, 184506 (2012)].

  11. Stress relaxation of thermally bowed fuel pins

    International Nuclear Information System (INIS)

    Crossland, I.G.; Speight, M.V.

    1983-01-01

    The presence of cross-pin temperature gradients in nuclear reactor fuel pins produces differential thermal expansion which, in turn, causes the fuel pin to bow elastically. If the pin is restrained in any way, such thermal bowing causes the pin to be stressed. At high temperatures these stresses can relax by creep and it is shown here that this causes the pin to suffer an additional permanent deflection, so that when the cross-pin temperature difference is removed the pin remains bowed. By representing the cylindrical pin by an equivalent I-beam, the present work examines this effect when it takes place by secondary creep. Two restraint systems are considered, and it is demonstrated that the rate of relaxation depends mainly upon the creep equation, and hence the temperature, and also the magnitude of the initial stresses. (author)

  12. Defect pin behaviour in the DFR

    International Nuclear Information System (INIS)

    Sloss, W.M.; Bagley, K.Q.; Edmonds, E.; Potter, P.E.

    1979-01-01

    A program of defective fuel pin irradiations has been carried out in the DFR. This program employed fuel pins which had failed during previous irradiations (natural defects) and pins in which simulated failures (artificial defects) had been induced prior to irradiation or during an intermediate examination stage at moderate or substantial burnups. The artificial defects simulated longitudinal ruptures and were normally located at positions near the top, middle and bottom of the pin where clad temperatures were 450, 540 and 630 0 C respectively. The fuel was mixed U-Pu oxide, and fuel form, stoichiometry, clad type, pin diameter, linear rating, and burnup were among the variables examined. The defect pin tests were normally carried out in single pin or trefoil type vehicles. After irradiation all the pins were subjected to the normal nondestructive examination procedures and the visual, radiographic, gamma-scanning, and dimensional change results are presented. Several pins were destructively examined and the metallographic data are discussed

  13. MONJU fuel pin performance analysis

    International Nuclear Information System (INIS)

    Kitagawa, H.; Yamanaka, T.; Hayashi, H.

    1979-01-01

    Monju fuel pin has almost the same properties as other LMFBR fuel pins, i.e. Phenix, PFR, CRBR, but would be irradiated under severe conditions: maximum linear heat rate of 381 watt/cm, hot spot cladding temperature of 675 deg C, peak burnup of 131,000 MWd/t, peak fluence (E greater than 0.1 MeV) of 2.3 10 23 n/cm 2 . In order to understand in-core performance of Monju fuel pin, its thermal and mechanical behaviour was predicted using the fast running performance code SIMPLE. The code takes into account pellet-cladding interaction due to thermal expansion and swelling, gap conductance, structural changes of fuel pellets, fission product gas release with burnup and temperature increase, swelling and creep of fuel pellets, corrosion of cladding due to sodium flow and chemical attack by fission products, and cumulative damage of the cladding due to thermal creep

  14. Neutron radiography of fuel pins

    International Nuclear Information System (INIS)

    Jackson, C.N. Jr.; Powers, H.G.; Burgess, C.A.

    1975-01-01

    Neutron radiography performed with a reactor source has been shown to be a superior radiographic method for the examination of unirradiated mixed oxide fuel pins at the Hanford Engineering Development Laboratory. Approximately 1,700 fuel pins were contained in a sample that demonstrated the capability of the method for detecting laminations, structural flaws, fissile density variation, hydrogenous inclusions and voids in assembled fuel pins. The nature, extent, and importance of the detected conditions are substantiated by gamma autoradiography and by destructive analysis employing alpha autoradiography, electron microprobe and visual inspection. Also, a series of radiographs illustrate the response of neutron radiography as compared to low voltage and high voltage x-ray and gamma source Iridium 192 radiography. (U.S.)

  15. Flux pinning by voids in surface-oxidized superconducting niobium and vanadium

    International Nuclear Information System (INIS)

    Meij, G.P. van der.

    1984-03-01

    The volume pinning force in several niobium and vanadium samples with voids is determined at various temperatures. Reasonable agreement is found with the collective pinning theory of Larkin and Ovchinnikov above the field of maximum pinning, if the flux line lattice is assumed to be amorphous in this region and if the elementary pinning force is calculated from the quasi-classical theory of Thuneberg, Kurkijaervi, and Rainer. Also some history and relaxation effects are studied in an alternating field. A qualitative explanation is given in terms of flux line dislocations, which reduce the shear strength of the flux line lattice. (Auth.)

  16. Mode of failure of LMFBR fuel pins

    International Nuclear Information System (INIS)

    Washburn, D.F.

    1975-01-01

    The objectives of the irradiation test described were to evaluate mixed-oxide fuel performance and to confirm the design adequacy of the FFTF fuel pins. After attainment of the initial objectives the irradiation of several of the original fuel pins was continued until a cladding breach occurred. The consequences of a cladding breach were evaluated by reconstituting the original 37-pin subassembly into two 19-pin subassemblies after a burnup at 50,000 MWd/MTM (5.2 a/o). The original pins were supplemented with fresh pins as necessary. Irradiation of the subassemblies was continued until a cladding breach occurred. Results are presented and discussed

  17. Multicenter Study of Pin Site Infections and Skin Complications Following Pinning of Pediatric Supracondylar Humerus Fractures.

    Science.gov (United States)

    Combs, Kristen; Frick, Steven; Kiebzak, Gary

    2016-12-03

    Pediatric supracondylar humerus fractures are the most common elbow fractures in pediatric patients. Surgical fixation using pins is the primary treatment for displaced fractures. Pin site infections may follow supracondylar humerus fracture fixation; the previously reported incidence rate in the literature is 2.34%, but there is significant variability in reported incidence rates of pin site infection. This study aims to define the incidence rate and determine pre-, peri-, and postoperative factors that may contribute to pin site infection following operative reduction, pinning, and casting. A retrospective chart analysis was performed over a one-year period on patients that developed pin site infection. A cast care form was added to Nemours' electronic medical records (EMR) system (Epic Systems Corp., Verona, WI) to identify pin site infections for retrospective review. The cast care form noted any inflamed or infected pins. Patients with inflamed or infected pin sites underwent a detailed chart review. Preoperative antibiotic use, number and size of pins used, method of postoperative immobilization, pin dressings, whether postoperative immobilization was changed prior to pin removal, and length of time pins were in place was recorded. A total of 369 patients underwent operative reduction, pinning, and casting. Three patients developed a pin site infection. The pin site infection incidence rate was 3/369=0.81%. Descriptive statistics were reported for the three patients that developed pin site infections and three patients that developed pin site complications. Pin site infection development is low. Factors that may contribute to the development of pin site infection include preoperative antibiotic use, length of time pins are left in, and changing the cast prior to pin removal.

  18. Fuel pin bowing in CAGR

    International Nuclear Information System (INIS)

    Crossland, I.G.

    1982-01-01

    Some of the more important mechanisms by which pin bowing can occur in Advanced Gas Cooled Reactors are examined. These include creep relaxation of the stresses which occur when thermal bowing is restrained and asymmetric axial clad creep. The clad temperature changes which accompany such bowing are also investigated and the theoretical results briefly compared with the empirical behaviour. (author)

  19. Suspension scheme for fuel pin

    International Nuclear Information System (INIS)

    Butts, C.E.; Gray, H.C.

    1975-01-01

    A description is presented of a nuclear fuel pin suspension arrangement comprising, in combination, a rod; a first beam member connected to said rod at one end; a plurality of parallel-spaced slidable fuel support plates attached to said first beam member, the longitudinal axis of first beam member being perpendicular to the longitudinal axis of each of said fuel support plates, a first coupling means disposed along the length of the first beam member for permitting slidable fuel support plates parallel movement with respect to the longitudinal axis of said first beam member, a second coupling means located at one end of each of slidable fuel plates for slidably engaging first coupling means of first beam member, a second beam member connected to the other end of each of parallel-spaced slidable fuel support plates and providing an extension, second beam member being provided with a third coupling means disposed along the length of second beam member at one end thereof; and a plurality of fuel pins provided with a fourth coupling means located at one end of each fuel pin for slidably engaging third coupling means of second beam member to permit each fuel pin parallel movement with respect to the longitudinal axis of second beam member. (U.S.)

  20. Temperature dependent pinning landscapes in REBCO thin films

    Science.gov (United States)

    Jaroszynski, Jan; Constantinescu, Anca-Monia; Hu, Xinbo Paul

    2015-03-01

    The pinning landscapes of REBCO (RE=rare earth elements) thin films have been a topic of study in recent years due to, among other reasons, their high ability to introduce various phases and defects. Pinning mechanisms studies in high temperature superconductors often require detailed knowledge of critical current density as a function of magnetic field orientation as well as field strength and temperature. Since the films can achieve remarkably high critical current, challenges exist in evaluating these low temperature (down to 4.2 K) properties in high magnetic fields up to 30 T. Therefore both conventional transport, and magnetization measurements in a vibrating coil magnetometer equipped with rotating sample platform were used to complement the study. Our results clearly show an evolution of pinning from strongly correlated effects seen at high temperatures to significant contributions from dense but weak pins that thermal fluctuations render ineffective at high temperatures but which become strong at lower temperatures Support for this work is provided by the NHMFL via NSF DRM 1157490

  1. Pinning synchronization of a mobile agent network

    International Nuclear Information System (INIS)

    Wang, Lei; Sun, You-xian

    2009-01-01

    We investigate the problem of controlling a group of mobile agents in a plane in order to move them towards a desired orbit via pinning control, in which each agent is associated with a chaotic oscillator coupled with those of neighboring agents, and the pinning strategy is to have the common linear feedback acting on a small fraction of agents by random selection. We explore the effects of the pinning probability, feedback gains and agent density in the pinning synchronization of a mobile agent network under a fast-switching constraint, and perform numerical simulations for validation. In particular, we show that there exists a critical pinning density for network synchronization with an unbounded region: above the threshold, the dynamical network can be controlled by pinning; below it, anarchy prevails. And for the network with a single bounded synchronization region, pinning control has little effect as regards enhancing network synchronizability

  2. Cell polarity and patterning by PIN trafficking through early endosomal compartments in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Hirokazu Tanaka

    2013-05-01

    Full Text Available PIN-FORMED (PIN proteins localize asymmetrically at the plasma membrane and mediate intercellular polar transport of the plant hormone auxin that is crucial for a multitude of developmental processes in plants. PIN localization is under extensive control by environmental or developmental cues, but mechanisms regulating PIN localization are not fully understood. Here we show that early endosomal components ARF GEF BEN1 and newly identified Sec1/Munc18 family protein BEN2 are involved in distinct steps of early endosomal trafficking. BEN1 and BEN2 are collectively required for polar PIN localization, for their dynamic repolarization, and consequently for auxin activity gradient formation and auxin-related developmental processes including embryonic patterning, organogenesis, and vasculature venation patterning. These results show that early endosomal trafficking is crucial for cell polarity and auxin-dependent regulation of plant architecture.

  3. Reconstructing weak values without weak measurements

    International Nuclear Information System (INIS)

    Johansen, Lars M.

    2007-01-01

    I propose a scheme for reconstructing the weak value of an observable without the need for weak measurements. The post-selection in weak measurements is replaced by an initial projector measurement. The observable can be measured using any form of interaction, including projective measurements. The reconstruction is effected by measuring the change in the expectation value of the observable due to the projector measurement. The weak value may take nonclassical values if the projector measurement disturbs the expectation value of the observable

  4. Assessment of pin-by-pin fission rate distribution within MOX/UO{sub 2} fuel assembly using MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Heba Kareem; Amin, Esmat [Nuclear and Radiological Regulation Authority (NRRA), Cairo (Egypt). Safety Engineering Dept.

    2016-03-15

    The aim of the present paper is to assess the calculations of pin-by-pin group integrated fission rates within MOX/UO{sub 2} Fuel assemblies using the Monte Carlo code MCNP2.7c with two sets of the available latest nuclear data libraries used for calculating MOX-fueled systems. The data that are used in this paper are based on the benchmark by the NEA Nuclear Science Committee (NSC). The k{sub ∞} and absorption/fission reaction rates per isotope, k{sub eff} and pin-by-pin group integrated fission rates on 1/8 fraction of the geometry are determined. To assess the overall pin-by-pin fission rate distribution, the collective per cent error measures were investigated. The results of AVG, MRE and RMS error measures were less than 1 % error. The present results are compared with other participants using other Monte Carlo codes and with CEA results that were taken in the benchmark as reference. The results with ENDF/B-VI.6 are close to the results received by MVP (JENDL3.2) and SCALE 4.2 (JEF2.2). The results with ENDF/BVII.1 give higher values of k{sub ∞} reflecting the changes in the newer evaluations. In almost all results presented here, the MCNP calculated results with ENDF/B VII.1 should be considered more than those obtained by using other Monte Carlo codes and nuclear data libraries. The present calculations may be consider a reference for evaluating the numerical schemes in production code systems, as well as the global performance including cross-section data reduction methods as the calculations used continuous energy and no geometrical approximations.

  5. Unicortical self-drilling external fixator pins reduce thermal effects during pin insertion.

    Science.gov (United States)

    Greinwald, Markus; Varady, Patrick A; Augat, Peter

    2017-12-14

    External fixation is associated with the risk of pin loosening and pin infection potentially associated to thermal bone necrosis during pin insertion. This study aims to investigate if the use of external fixator systems with unicortical pins reduces the heat production during pin insertion compared to fixators with bicortical pins. Porcine bone specimens were employed to determine bone temperatures during insertion of fixator pins. Two thermographic cameras were used for a simultaneous temperature measurement on the bone surface (top view) and a bone cross-section (front view). Self-drilling unicortical and bicortical pins were inserted at different rotational speeds: (30-600) rpm. Maximum and mean temperatures of the emerging bone debris, bone surface and bone cross-section were analyzed. Maximum temperatures of up to 77 ± 26 °C were measured during pin insertion in the emerging debris and up to 42 ± 2 °C on the bone surface. Temperatures of the emerging debris increased with increasing rotational speeds. Bicortical pin insertion generated significantly higher temperatures at low insertion speed (30 rpm) CONCLUSION: The insertion of external fixator pins can generate a considerable amount of heat around the pins, primarily emerging from bone debris and at higher insertion speeds. Our findings suggest that unicortical, self-drilling fixator pins have a decreased risk for thermal damage, both to the surrounding tissue and to the bone itself.

  6. Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

    Energy Technology Data Exchange (ETDEWEB)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: bebe.luna_s@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  7. Pin Wire Coating Trip Report

    International Nuclear Information System (INIS)

    Spellman, G P

    2004-01-01

    A meeting to discuss the current pin wire coating problems was held at the Reynolds plant in Los Angeles on 2MAR04. The attendance list for Reynolds personnel is attached. there was an initial presentation which gave a brief history and the current status of pin wire coating at Reynolds. There was a presentation by Lori Primus on the requirements and issues for the coating. There was a presentation by Jim Smith of LANL on the chemistry and to some extent process development done to date. There was a long session covering what steps should be taken in the short term and, to a lesser extent, the long term. The coating currently being used is a blend of two polymers, polyethersulfone and polyparabanic acid (PPA) and some TiO2 filler. This system was accepted and put into production when the pin wire coating was outsourced to another company in 1974. When that company no longer was interested, the wire coating was brought in-house to Reynolds. At that time polyparabanic acid was actually a commercial product available from Exxon under the trade name Tradlon. However, it appears that the material used at Reynolds was synthesized locally. Also, it appears that a single large batch was synthesized in that time period and used up to 1997 when the supply ran out. The reason for the inclusion of TiO2 is not known although it does act as a rheological thickener. However, a more controlled thickening can be obtained with materials such as fumed silica. This material would have less likelihood of causing point imperfections in the coatings. Also, the mixing technique being used for all stages of the process is a relatively low shear ball mill process and the author recommends a high shear process such as a three roll paint mill, at least for the final mixing. Since solvent is added to the powder at Reynolds, it may be that they need to have the paint mill there

  8. Transient survivability of LMR oxide fuel pins

    International Nuclear Information System (INIS)

    Weber, E.T.; Pitner, A.L.; Bard, F.E.; Culley, G.E.; Hunter, C.W.

    1986-01-01

    Fuel pin integrity during transient events must be assessed for both the core design and safety analysis phases of a reactor project. A significant increase in the experience related to limits of integrity for oxide fuel pins in transient overpower events has been realized from testing of fuel pins irradiated in FFTF and PFR. Fourteen FFTF irradiated fuel pins were tested in TREAT, representing a range of burnups, overpower ramp rates and maximum overpower conditions. Results of these tests along with similar testing in the PFR/TREAT program, provide a demonstration of significant safety margins for oxide fuel pins. Useful information applied in analytical extrapolation of fuel pin test data have been developed from laboratory transient tests on irradiated fuel cladding (FCTT) and on unirradiated fuel pellet deformation. These refinements in oxide fuel transient performance are being applied in assessment of transient capabilities of long lifetime fuel designs using ferritic cladding

  9. Cesium migration in LMFBR fuel pins

    International Nuclear Information System (INIS)

    Karnesky, R.A.; Jost, J.W.; Stone, I.Z.

    1978-10-01

    The factors affecting the axial migration of cesium in mixed oxide fuel pins and the effects of cesium migration on fuel pin performance are examined. The development and application of a correlated model which will predict the occurrence of cesium migration in a mixed oxide (75 w/o UO 2 + 25 w/o PuO 2 ) fuel pins over a wide range of fabrication and irradiation conditions are described

  10. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  11. FFTF fuel pin design bases and performance

    International Nuclear Information System (INIS)

    Cox, C.M.; Hanson, J.E.; Roake, W.E.; Slember, R.J.; Weber, C.E.; Millunzi, A.C.

    1975-04-01

    The FFTF fuel pin was conservatively designed to meet thermal and structural performance requirements in the categories normal operation, upset events, emergency events, and hypothetical, faulted events. The fuel pin operating limits consistent with these requirements were developed from a strong fuel pin irradiation testing program scoped to define the performance capability under relevant steady state and transient conditions. Comparison of the results of the irradiation testing program with design requirements indicates that the FFTF fuel pin can exceed its goal burnup of 80,000 MWd/MTM. (U.S.)

  12. Integral Fast Reactor fuel pin processor

    International Nuclear Information System (INIS)

    Levinskas, D.

    1993-01-01

    This report discusses the pin processor which receives metal alloy pins cast from recycled Integral Fast Reactor (IFR) fuel and prepares them for assembly into new IFR fuel elements. Either full length as-cast or precut pins are fed to the machine from a magazine, cut if necessary, and measured for length, weight, diameter and deviation from straightness. Accepted pins are loaded into cladding jackets located in a magazine, while rejects and cutting scraps are separated into trays. The magazines, trays, and the individual modules that perform the different machine functions are assembled and removed using remote manipulators and master-slaves

  13. Magnetic pinning in superconductor-ferromagnet multilayers

    International Nuclear Information System (INIS)

    Bulaevskii, L. N.; Chudnovsky, E. M.; Maley, M. P.

    2000-01-01

    We argue that superconductor/ferromagnet multilayers of nanoscale period should exhibit strong pinning of vortices by the magnetic domain structure in magnetic fields below the coercive field when ferromagnetic layers exhibit strong perpendicular magnetic anisotropy. The estimated maximum magnetic pinning energy for single vortex in such a system is about 100 times larger than the pinning energy by columnar defects. This pinning energy may provide critical currents as high as 10 6 -10 7 A/cm 2 at high temperatures (but not very close to T c ) at least in magnetic fields below 0.1 T. (c) 2000 American Institute of Physics

  14. Magnetic pinning in superconductor-ferromagnet multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bulaevskii, L. N. [Department of Physics and Astronomy, CUNY Lehman College 250 Bedford Park Boulevard West, Bronx, New York 10468-1589 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Chudnovsky, E. M. [Department of Physics and Astronomy, CUNY Lehman College, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589 (United States); Maley, M. P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2000-05-01

    We argue that superconductor/ferromagnet multilayers of nanoscale period should exhibit strong pinning of vortices by the magnetic domain structure in magnetic fields below the coercive field when ferromagnetic layers exhibit strong perpendicular magnetic anisotropy. The estimated maximum magnetic pinning energy for single vortex in such a system is about 100 times larger than the pinning energy by columnar defects. This pinning energy may provide critical currents as high as 10{sup 6}-10{sup 7} A/cm{sup 2} at high temperatures (but not very close to T{sub c}) at least in magnetic fields below 0.1 T. (c) 2000 American Institute of Physics.

  15. Fabrication of FFTF fuel pin wire wrap

    International Nuclear Information System (INIS)

    Epperson, E.M.

    1980-06-01

    Lateral spacing between FFTF fuel pins is required to provide a passageway for the sodium coolant to flow over each pin to remove heat generated by the fission process. This spacing is provided by wrapping each fuel pin with type 316 stainless steel wire. This wire has a 1.435mm (0.0565 in.) to 1.448mm (0.0570 in.) diameter, contains 17 +- 2% cold work and was fabricated and tested to exacting RDT Standards. About 500 kg (1100 lbs) or 39 Km (24 miles) of fuel pin wrap wire is used in each core loading. Fabrication procedures and quality assurance tests are described

  16. Spectroscopic amplifier for pin diode

    International Nuclear Information System (INIS)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R.

    2014-10-01

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  17. Reduction of halo pin site morbidity with a new pin care regimen.

    Science.gov (United States)

    Kazi, Hussain Anthony; de Matas, Marcus; Pillay, Robin

    2013-06-01

    A retrospective analysis of halo device associated morbidity over a 4-year period. To assess the impact of a new pin care regimen on halo pin site related morbidity. Halo orthosis treatment still has a role in cervical spine pathology, despite increasing possibilities of open surgical treatment. Published figures for pin site infection range from 12% to 22% with pin loosening from 7% to 50%. We assessed the outcome of a new pin care regimen on morbidity associated with halo spinal orthoses, using a retrospective cohort study from 2001 to 2004. In the last two years, our pin care regimen was changed. This involved pin site care using chlorhexidene & regular torque checking as part of a standard protocol. Previously, povidone iodine was used as skin preparation in theatre, followed by regular sterile saline cleansing when pin sites became encrusted with blood. There were 37 patients in the series, the median age was 49 (range, 22-83) and 20 patients were male. The overall infection rate prior to the new pin care protocol was 30% (n=6) and after the introduction, it dropped to 5.9% (n=1). This difference was statistically significant (p<0.05). Pin loosening occurred in one patient in the group prior to the formal pin care protocol (3%) and none thereafter. Reduced morbidity from halo use can be achieved with a modified pin cleansing and tightening regimen.

  18. Phosphorylation of conserved PIN motifs directs Arabidopsis PIN1 polarity and auxin transport

    NARCIS (Netherlands)

    Huang, F.; Kemel Zago, M.; Abas, L.; van Marion, A.; Galván-Ampudia, C.S.; Offringa, R.

    2010-01-01

    Polar cell-to-cell transport of auxin by plasma membrane-localized PIN-FORMED (PIN) auxin efflux carriers generates auxin gradients that provide positional information for various plant developmental processes. The apical-basal polar localization of the PIN proteins that determines the direction of

  19. Synchronizability on complex networks via pinning control

    Indian Academy of Sciences (India)

    Keywords. Complex network; the pinning synchronization; synchronizability. ... The findings reveal the relationship between the decreasing speed of maximum eigenvalue sequence of the principal submatrices for coupling matrix and the synchronizability on complex networks via pinning control. We discuss the ...

  20. Breached-pin testing in the US

    International Nuclear Information System (INIS)

    Mahagin, D.E.; Lambert, J.D.B.

    1981-04-01

    Experience gained at EBR-II by the late 1970's from a significant number of failures in experimental fuel-pin irradiations forms the basis of a program directed towards the characterization of breached pins. The questions to be answered and the issues raised by further testing are discussed

  1. Vortex Dynamics in Superconductors with Different Types of Pinning Potentials

    International Nuclear Information System (INIS)

    Laguna, Maria Fabiana

    2001-01-01

    of the solid phase and we determine the conditions for the existence of individual and collective pinning

  2. TACO: fuel pin performance analysis

    International Nuclear Information System (INIS)

    Stoudt, R.H.; Buchanan, D.T.; Buescher, B.J.; Losh, L.L.; Wilson, H.W.; Henningson, P.J.

    1977-08-01

    The thermal performance of fuel in an LWR during its operational lifetime must be described for LOCA analysis as well as for other safety analyses. The determination of stored energy in the LOCA analysis, for example, requires a conservative fuel pin thermal performance model that is capable of calculating fuel and cladding behavior, including the gap conductance between the fuel and cladding, as a function of burnup. The determination of parameters that affect the fuel and cladding performance, such as fuel densification, fission gas release, cladding dimensional changes, fuel relocation, and thermal expansion, should be accounted for in the model. Babcock and Wilcox (B and W) has submitted a topical report, BAW-10087P, December 1975, which describes their thermal performance model TACO. A summary of the elements that comprise the TACO model and an evaluation are presented

  3. Pinning impulsive control algorithms for complex network

    International Nuclear Information System (INIS)

    Sun, Wen; Lü, Jinhu; Chen, Shihua; Yu, Xinghuo

    2014-01-01

    In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms

  4. Resistance projection welding small pins in vacuum tube feedthrough assembly

    International Nuclear Information System (INIS)

    Kuncz, F. Jr.

    1980-01-01

    Resistance projection welding of two stainless steel pins to a cup is successfully accomplished by specially designed electrodes and by forming domes on the pin ends. Details of electrode and pin construction are given, as well as welding parameters

  5. Debonding analyses of closely spaced Z-pins bridging an unbonded interface

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang

    2009-01-01

    In this study the plasticity, the spatial stress distribution and the debonding behavior of a metallic Z-pin bridging the unbonded interface between two substrates of an elasto-plastic material subjected to shear loading (mode II) are analyzed numerically by the finite element method taking full...... account of finite strains. For a weakly bonded Z-pin perpendicular to the substrates the overall average stress-strain response depicts a rather sudden stress drop which is not seen for stronger interfaces in the load range investigated. This stress drop is caused by dual debonding at different locations...

  6. Pin fin compliant heat sink with enhanced flexibility

    Science.gov (United States)

    Schultz, Mark D.

    2018-04-10

    Heat sinks and methods of using the same include a top and bottom plate, at least one of which has a plurality of pin contacts flexibly connected to one another, where the plurality of pin contacts have vertical and lateral flexibility with respect to one another; and pin slice layers, each having multiple pin slices, arranged vertically between the top and bottom plates such that the plurality of pin slices form substantially vertical pins connecting the top and bottom plates.

  7. Cesium chemistry in GCFR fuel pins

    International Nuclear Information System (INIS)

    Fee, D.C.; Johnson, C.E.

    1979-01-01

    The fuel rod design for the Gas Cooled Fast-Breeder Reactor (GCFR) is similar to that employed for the Liquid Metal Fast Breeder Reactor (LMFBR) with the exception of the unique features inherent to the use of helium as the coolant. These unique design features include the use of (1) vented and pressure-equalized fuel rods, and (2) ribbed cladding along 75% of the fuel section. The former design feature enables reduction in cladding thickness and prevention of possible creep collapse of the cladding due to the high coolant pressure (8.5 MPa). The latter design feature brings about improved heat transfer characteristics. Each GCFR fuel rod is vented to a manifold whereby gaseous fission products diffusing out of the fuel pin are retained on charcoal traps. As a result, the internal pressure of a GCFR fuel pin does not increase during irradiation. In addition, the venting system also maintains the pressure within the fuel pin slightly below (0.3 to 0.5 MPa) the coolant pressure outside the fuel pin. Consequently, should a breach occur in the cladding, helium flows into the breached fuel pin thereby minimizing fission product contamination of the coolant. These desirable aspects of a GCFR fuel pin can be maintained only as long as axial gas transport paths are available and operating within the fuel pin

  8. Vortex lattice melting, pinning and kinetics

    International Nuclear Information System (INIS)

    Doniach, S.; Ryu, S.; Kapitulnik, A.

    1994-01-01

    The phenomenology of the high T c superconductors is discussed both at the level of the thermodynamics of melting of the Abrikosov flux lattice and in terms of the melting and kinetics of the flux lattice for a pinned system. The authors review results on 3D melting obtained by a Monte Carlo simulation approach in which the 2D open-quotes pancakeclose quotes vortices are treated as statistical variables. The authors discuss pinning in the context of the strong pinning regime in which the vortex density given in terms of the applied field B is small compared to that represented by an effective field B pin measuring the pinning center density. The authors introduce a new criterion for the unfreezing of a vortex glass on increase of magnetic field or temperature, in the strong pinning, small field unit. The authors model this limit in terms of a single flux line interacting with a columnar pin. This model is studied both analytically and by computer simulation. By applying a tilt potential, the authors study the kinetics of the vortex motion in an external current and show that the resulting current-voltage characteristic follows a basic vortex glass-like scaling relation in the vicinity of the depinning transition

  9. Weak differentiability of product measures

    NARCIS (Netherlands)

    Heidergott, B.F.; Leahu, H.

    2010-01-01

    In this paper, we study cost functions over a finite collection of random variables. For these types of models, a calculus of differentiation is developed that allows us to obtain a closed-form expression for derivatives where "differentiation" has to be understood in the weak sense. The technique

  10. Electro-optical fuel pin identification system

    International Nuclear Information System (INIS)

    Kirchner, T.L.

    1978-09-01

    A prototype Electro-Optical Fuel Pin Identification System referred to as the Fuel Pin Identification System (FPIS) has been developed by the Hanford Engineering Development Laboratory (HEDL) in support of the Fast Flux Test Facility (FFTF) presently under construction at HEDL. The system is designed to remotely read an alpha-numeric identification number that is roll stamped on the top of the fuel pin end cap. The prototype FPIS consists of four major subassemblies: optical read head, digital compression electronics, video display, and line printer

  11. Flux pinning characteristics of YBCO coated conductor

    International Nuclear Information System (INIS)

    Matsushita, T.; Watanabe, T.; Fukumoto, Y.; Yamauchi, K.; Kiuchi, M.; Otabe, E.S.; Kiss, T.; Watanabe, T.; Miyata, S.; Ibi, A.; Muroga, T.; Yamada, Y.; Shiohara, Y.

    2005-01-01

    Flux pinning properties of PLD-processed YBCO coated conductors deposited on IBAD substrate are investigated. The thickness of YBCO layer is changed in the range of 0.27-1.0 μm. The thickness dependence of critical current density, n-value and irreversibility field are measured in a wide range of magnetic field. The results are compared with the theoretical flux creep-flow model. It is found that these pinning properties are strongly influenced by the thickness as well as the pinning strength. Optimum condition for high field application of this superconductor is discussed

  12. Pinning and creep in superconductors

    International Nuclear Information System (INIS)

    Ovchinnikov, Yu.N.

    1994-01-01

    All superconductors can be separated into two large groups: type I and type II. The behaviour of these two groups in a magnetic field is quite different. The superconductors of type I, in a strong magnetic field, enter the intermediate state. Phenomenological picture of this state was given by Landau. The type II superconductors, in strong magnetic fields, form the mixed state (or Shubnikov phase). The microscopic picture of the mixed state was given by Abrikosov on the basis of Ginzburg-Landau equations. In ideal homogeneous superconductors the free energy is not changed if all the vortex structure is shifted on some distance u. The transport current will be proportional, therefore, to the electric field E. All the real superconductors, however, are inhomogeneous. Inhomogeneities interact with vortex lattice and pin it. In this new state the transport current below some critical value does not lead to the motion of the flux lattice and to the energy dissipation. The value of critical current strongly depends on the type of inhomogeneities, on the value of magnetic field and on temperature. In new layered superconductors, the critical current depends also on the orientation of the magnetic field B with respect to the layer planes. Temperature and quantum fluctuations lead to the transition between different metastable states in superconductors with current. As a result, the vortex lattice slowly moves (creep phenomenon). Below we will briefly discuss all these phenomena. (orig.)

  13. Nonlinear waves and weak turbulence

    CERN Document Server

    Zakharov, V E

    1997-01-01

    This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.

  14. Vortex pinning by point defect in superconductors

    International Nuclear Information System (INIS)

    Liao Hongyin; Zhou Shiping; Du Haochen

    2003-01-01

    We apply the periodic time-dependent Ginzburg-Landau model to study vortex distribution in type-II superconductors with a point-like defect and square pinning array. A defect site will pin vortices, and a periodic pinning array with right geometric parameters, which can be any form designed in advance, shapes the vortex pattern as external magnetic field varies. The maximum length over which an attractive interaction between a pinning centre and a vortex extends is estimated to be about 6.0ξ. We also derive spatial distribution expressions for the order parameter, vector potential, magnetic field and supercurrent induced by a point defect. Theoretical results and numerical simulations are compared with each other and they are consistent

  15. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du

    2015-01-01

    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  16. Nuclear fuel pin controlled failure device

    International Nuclear Information System (INIS)

    Schlenker, L.D.

    1975-01-01

    Each fuel pin of a fuel assembly for a water-cooled nuclear reactor is provided with means for rupturing the cladding tube at a predetermined location if an abnormal increase in pressure of the gases present occurs due to a loss-of-coolant accident. Preferably all such rupture means are oriented to minimize the hydraulic resistance to the flow of emergency core coolant such as all rupture means pointing in the same direction. Rupture means may be disposed at different elevations in adjacent fuel pins and, further, fuel pins may be provided with two or more rupture means, one of which is in the upper portion of the fuel pin. Rupture means are mechanical as by providing a locally weakened condition of a controlled nature in the cladding. (U.S.)

  17. Ultrasonic inspections of fuel alignment pins

    International Nuclear Information System (INIS)

    Rathgeb, W.; Schmid, R.

    1994-01-01

    As a remedy to the practical problem of defects in fuel alignment pins made of Inconel X750, an inspection technique has been developed which fully meets the requirements of detecting defects. The newly used fuel alignment pins made of austenite are easy to test and therefore satisfy the necessity of further inspections.For the fuel alignment pins of the upper core structure a safe and fast inspection technique was made available. The inspection sensitivity is high and it is possible to give quantitative directions concerning defect orientation and depth. After the required inspections had been concluded in 1989, a total of 18 inspections were carried out in various national and international nuclear power plants in the following years. During this time more than 6000 fuel alignment pines were examined.For the fuel alignment pins the inspection technique provided could increase the understanding of the defect process. This technique contributed to the development of an adaptive and economical repair strategy. ((orig.))

  18. How and why discontinuous multiple-in-line-damage results in much higher Jc than continuous columnar pinning centres

    International Nuclear Information System (INIS)

    Weinstein, Roy; Gandini, Alberto; Sawh, Ravi; Mayes, Bill; Parks, Drew

    2006-01-01

    We review a recent experiment in which pinning centres, composed of discontinuous multiple-in-line damage (MILD), were compared to continuous columnar pinning centres (CCPCs). The methods used, results of the experiment, and the initial steps taken toward a phenomenological theory explaining the unusual results, are discussed. Experimental results show that MILD pinning centres, despite their reduced pinning potential, are far superior to CCPCs. Using MILD pinning, a new record J c has been achieved in large grain YBCO. The value of H irr (MILD) is comparable to, or larger, than H irr (CCPCs). Pinning effects alone, with no modification of texture, weak links or oxygenation of the YBCO, increase J c by as much as a factor of 17. Splay is expected to further increase this factor. The experimental dependence of J c on the energy lost by the ion per unit length is approximately reproduced by a phenomenological theory, including only the effects of diminished percolation, critical temperature, and pinning potential

  19. Application of PIN diodes in Physics Research

    International Nuclear Information System (INIS)

    Ramirez-Jimenez, F. J.; Mondragon-Contreras, L.; Cruz-Estrada, P.

    2006-01-01

    A review of the application of PIN diodes as radiation detectors in different fields of Physics research is presented. The development and research in semiconductor technology, the use of PIN diodes in particle counting, X-and γ-ray spectroscopy, medical applications and charged particle spectroscopy are considered. Emphasis is made in the activities realized in the different research and development Mexican institutions dealing with this kind of radiation detectors

  20. IMp: The customizable LEGO® Pinned Insect Manipulator

    Directory of Open Access Journals (Sweden)

    Steen Dupont

    2015-02-01

    Full Text Available We present a pinned insect manipulator (IMp constructed of LEGO® building bricks with two axes of movement and two axes of rotation. In addition we present three variants of the IMp to emphasise the modular design, which facilitates resizing to meet the full range of pinned insect specimens, is fully customizable, collapsible, affordable and does not require specialist tools or knowledge to assemble.

  1. IMp: The customizable LEGO® Pinned Insect Manipulator

    Science.gov (United States)

    Dupont, Steen; Price, Benjamin; Blagoderov, Vladimir

    2015-01-01

    Abstract We present a pinned insect manipulator (IMp) constructed of LEGO® building bricks with two axes of movement and two axes of rotation. In addition we present three variants of the IMp to emphasise the modular design, which facilitates resizing to meet the full range of pinned insect specimens, is fully customizable, collapsible, affordable and does not require specialist tools or knowledge to assemble. PMID:25685035

  2. Anisotropic flux pinning in high Tc superconductors

    International Nuclear Information System (INIS)

    Kolesnik, S.; Igalson, J.; Skoskiewicz, T.; Szymczak, R.; Baran, M.; Pytel, K.; Pytel, B.

    1995-01-01

    In this paper we present a comparison of the results of FC magnetization measurements on several Pb-Sr-(Y,Ca)-Cu-O crystals representing various levels of flux pinning. The pinning centers in our crystals have been set up during the crystal growth process or introduced by neutron irradiation. Some possible explanations of the observed effects, including surface barrier, flux-center distribution and sample-shape effects, are discussed. ((orig.))

  3. Experimental study of flux pinning in NbN films and multilayers: Ultimate limits on critical currents in superconductors

    International Nuclear Information System (INIS)

    Gray, K.E.; Kampwirth, R.T.; Capone, D.W. II; Murduck, J.M.

    1988-08-01

    A flux pinning model is presented which predicts the maximum critical current density attainable in superconductors. That such a limit must exist comes from the realization that flux pinning is strongest in regions of weak superconductivity, but these regions cannot carry a large supercurrent. Since the same regions within the superconductor cannot be used for both pinning and supercurrent conductions, there must be an optimum mix, leading to a maximum J/sub c/. Measurements on films and multilayers of NbN have verified many details of the model including anisotropy effects and a strong reduction in J/sub c/ for defect spacings smaller than the flux core diameter. In an optimized multilayer the pinning force reached /approximately/22% of the theoretical maximum. The implications of these results on the practical applications of NbN films and on the maximum critical current density in the new high temperature superconductors are also discussed. 24 refs., 4 figs

  4. Investigation on macroscopic cross section model for BWR pin-by-pin core analysis - 118

    International Nuclear Information System (INIS)

    Fujita, T.; Tada, K.; Yamamoto, A.; Yamane, Y.; Kosaka, S.; Hirano, G.

    2010-01-01

    A cross section model used in the pin-by-pin core analysis for BWR is investigated. In the pin-by-pin core calculation method, pin-cell averaged cross sections are calculated for many combinations of state and history variables that have influences on the cross section and are tabulated prior to the core calculations. Variation of a cross section in a core simulator is classified into two different types, i.e., the instantaneous effect and the history effect. The instantaneous effect is incorporated by the variation of cross section which is caused by the instantaneous change of state variables. For this effect, the exposure, the void fraction, the fuel temperature, the moderator temperature and the control rod are used as indexes. The history effect is the cumulative effect of state variables. We treat this effect with a unified approach using the spectral history. To confirm accuracy of the cross section model, the pin-by-pin fission rate distribution and the k-infinity of fuel assembly which are obtained with the tabulated and the reference cross sections are compared. For the instantaneous effect, the present cross section model well reproduces the reference results for all off-nominal conditions. For the history effect, however, considerable differences both on the pin-by-pin fission rate distribution and the k-infinity are observed at high exposure points. (authors)

  5. A macroscopic cross-section model for BWR pin-by-pin core analysis

    International Nuclear Information System (INIS)

    Fujita, Tatsuya; Endo, Tomohiro; Yamamoto, Akio

    2014-01-01

    A macroscopic cross-section model used in boiling water reactor (BWR) pin-by-pin core analysis is studied. In the pin-by-pin core calculation method, pin-cell averaged cross sections are calculated for many combinations of core state and depletion history variables and are tabulated prior to core calculations. Variations of cross sections in a core simulator are caused by two different phenomena (i.e. instantaneous and history effects). We treat them through the core state variables and the exposure-averaged core state variables, respectively. Furthermore, the cross-term effect among the core state and the depletion history variables is considered. In order to confirm the calculation accuracy and discuss the treatment of the cross-term effect, the k-infinity and the pin-by-pin fission rate distributions in a single fuel assembly geometry are compared. Some cross-term effects could be negligible since the impacts of them are sufficiently small. However, the cross-term effects among the control rod history (or the void history) and other variables have large impacts; thus, the consideration of them is crucial. The present macroscopic cross-section model, which considers such dominant cross-term effects, well reproduces the reference results and can be a candidate in practical applications for BWR pin-by-pin core analysis on the normal operations. (author)

  6. Weakly clopen functions

    International Nuclear Information System (INIS)

    Son, Mi Jung; Park, Jin Han; Lim, Ki Moon

    2007-01-01

    We introduce a new class of functions called weakly clopen function which includes the class of almost clopen functions due to Ekici [Ekici E. Generalization of perfectly continuous, regular set-connected and clopen functions. Acta Math Hungar 2005;107:193-206] and is included in the class of weakly continuous functions due to Levine [Levine N. A decomposition of continuity in topological spaces. Am Math Mon 1961;68:44-6]. Some characterizations and several properties concerning weakly clopenness are obtained. Furthermore, relationships among weak clopenness, almost clopenness, clopenness and weak continuity are investigated

  7. Weak value controversy

    Science.gov (United States)

    Vaidman, L.

    2017-10-01

    Recent controversy regarding the meaning and usefulness of weak values is reviewed. It is argued that in spite of recent statistical arguments by Ferrie and Combes, experiments with anomalous weak values provide useful amplification techniques for precision measurements of small effects in many realistic situations. The statistical nature of weak values is questioned. Although measuring weak values requires an ensemble, it is argued that the weak value, similarly to an eigenvalue, is a property of a single pre- and post-selected quantum system. This article is part of the themed issue `Second quantum revolution: foundational questions'.

  8. Heterogeneous neutron-leakage model for PWR pin-by-pin calculation

    International Nuclear Information System (INIS)

    Li, Yunzhao; Zhang, Bin; Wu, Hongchun; Shen, Wei

    2017-01-01

    Highlights: •The derivation of the formula of the leakage model is introduced. This paper evaluates homogeneous and heterogeneous leakage models used in PWR pin-by-pin calculation. •The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. •Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. The computational cost of the newly proposed neutron balance scheme is much less than the power-method scheme and the linear-interpolation scheme. -- Abstract: When assembly calculation is performed with the reflective boundary condition, a leakage model is usually required in the lattice code. The previous studies show that the homogeneous leakage model works effectively for the assembly homogenization. However, it becomes different and unsettled for the pin-cell homogenization. Thus, this paper evaluates homogeneous and heterogeneous leakage models used in pin-by-pin calculation. The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. For practical reactor-core applications, the diffusion coefficients determined by the transport cross-section or by the leakage model are compared with each other to determine which one is more accurate for the Pressurized Water Reactor pin-by-pin calculation. Numerical results have demonstrated that the heterogeneous leakage model together with the diffusion coefficient determined by the heterogeneous leakage model would have the higher accuracy. The new buckling search

  9. Neighboring phosphoSer-Pro motifs in the undefined domain of IRAK1 impart bivalent advantage for Pin1 binding.

    Science.gov (United States)

    Rogals, Monique J; Greenwood, Alexander I; Kwon, Jeahoo; Lu, Kun Ping; Nicholson, Linda K

    2016-12-01

    The peptidyl prolyl isomerase Pin1 has two domains that are considered to be its binding (WW) and catalytic (PPIase) domains, both of which interact with phosphorylated Ser/Thr-Pro motifs. This shared specificity might influence substrate selection, as many known Pin1 substrates have multiple sequentially close phosphoSer/Thr-Pro motifs, including the protein interleukin-1 receptor-associated kinase-1 (IRAK1). The IRAK1 undefined domain (UD) contains two sets of such neighboring motifs (Ser131/Ser144 and Ser163/Ser173), suggesting possible bivalent interactions with Pin1. Using a series of NMR titrations with 15N-labeled full-length Pin1 (Pin1-FL), PPIase, or WW domain and phosphopeptides representing the Ser131/Ser144 and Ser163/Ser173 regions of IRAK1-UD, bivalent interactions were investigated. Binding studies using singly phosphorylated peptides showed that individual motifs displayed weak affinities (> 100 μm) for Pin1-FL and each isolated domain. Analysis of dually phosphorylated peptides binding to Pin1-FL showed that inclusion of bivalent states was necessary to fit the data. The resulting complex model and fitted parameters were applied to predict the impact of bivalent states at low micromolar concentrations, demonstrating significant affinity enhancement for both dually phosphorylated peptides (3.5 and 24 μm for peptides based on the Ser131/Ser144 and Ser163/Ser173 regions, respectively). The complementary technique biolayer interferometry confirmed the predicted affinity enhancement for a representative set of singly and dually phosphorylated Ser131/Ser144 peptides at low micromolar concentrations, validating model predictions. These studies provide novel insights regarding the complexity of interactions between Pin1 and activated IRAK1, and more broadly suggest that phosphorylation of neighboring Ser/Thr-Pro motifs in proteins might provide competitive advantage at cellular concentrations for engaging with Pin1. © 2016 Federation of European

  10. FLUX PINNING EFFECTS IN Ag-DOPED YBCO (123 SUPERCONDUCTOR

    Directory of Open Access Journals (Sweden)

    Madelen Pérez

    2010-07-01

    Full Text Available Polycrystalline samples of Ag+-doped YBCO (123 (YBa2 (Cu1-xAgx3O7-δwith 0≤x≤0.3 were produced by solid state reaction method. The Ag- doped YBCO samples showed higher critical current densities (Jc with a Jc maximum for samples doped with x=0.05. This behavior can be assigned to an increase of pinning forces. The irreversibility temperature (Tirr, also increased in doped samples as a function of Ag content, with the highest temperature for the sample doped with x=0.05, wich correlates well with the observed Jc increasing. However, samples doped with x>0.05 displayed a decreasing of electrical properties (less Tirr, less Jc, etc. atributed to an excess of Ag in the grain boundaries which, reduces the grain sizes and increases the number of weak- links.

  11. Whole-Pin Furnace system: An experimental facility for studying irradiated fuel pin behavior under potential reactor accident conditions

    International Nuclear Information System (INIS)

    Liu, Y.Y.; Tsai, H.C.; Donahue, D.A.; Pushis, D.O.; Savoie, F.E.; Holland, J.W.; Wright, A.E.; August, C.; Bailey, J.L.; Patterson, D.R.

    1990-05-01

    The whole-pin furnace system is a new in-cell experimental facility constructed to investigate how irradiated fuel pins may fail under potential reactor accident conditions. Extensive checkouts have demonstrated excellent performance in remote operation, temperature control, pin breach detection, and fission gas handling. The system is currently being used in testing of EBIR-II-irradiated Integral Fast Reactor (IFR) metal fuel pins; future testing will include EBR-II-irradiated mixed-oxide fuel pins. 7 refs., 4 figs

  12. Statistics of dislocation pinning at localized obstacles

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, A. [S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700098 (India); Bhattacharya, M., E-mail: mishreyee@vecc.gov.in; Barat, P. [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India)

    2014-10-14

    Pinning of dislocations at nanosized obstacles like precipitates, voids, and bubbles is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often studied at fundamental level by means of analytical tools, atomistic simulations, and finite element methods. Nevertheless, the information extracted from such studies cannot be utilized to its maximum extent on account of insufficient information about the underlying statistics of this process comprising a large number of dislocations and obstacles in a system. Here, we propose a new statistical approach, where the statistics of pinning of dislocations by idealized spherical obstacles is explored by taking into account the generalized size-distribution of the obstacles along with the dislocation density within a three-dimensional framework. Starting with a minimal set of material parameters, the framework employs the method of geometrical statistics with a few simple assumptions compatible with the real physical scenario. The application of this approach, in combination with the knowledge of fundamental dislocation-obstacle interactions, has successfully been demonstrated for dislocation pinning at nanovoids in neutron irradiated type 316-stainless steel in regard to the non-conservative motion of dislocations. An interesting phenomenon of transition from rare pinning to multiple pinning regimes with increasing irradiation temperature is revealed.

  13. Pinning impulsive control algorithms for complex network

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wen [School of Information and Mathematics, Yangtze University, Jingzhou 434023 (China); Lü, Jinhu [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Chen, Shihua [College of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China); Yu, Xinghuo [School of Electrical and Computer Engineering, RMIT University, Melbourne VIC 3001 (Australia)

    2014-03-15

    In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms.

  14. Second class weak currents

    International Nuclear Information System (INIS)

    Delorme, J.

    1978-01-01

    The definition and general properties of weak second class currents are recalled and various detection possibilities briefly reviewed. It is shown that the existing data on nuclear beta decay can be consistently analysed in terms of a phenomenological model. Their implication on the fundamental structure of weak interactions is discussed [fr

  15. Weak C* Hopf Symmetry

    OpenAIRE

    Rehren, K. -H.

    1996-01-01

    Weak C* Hopf algebras can act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents group symmetries. Possibilities to construct field algebras with weak C* Hopf symmetry from a given theory of local observables are discussed.

  16. Bagging Weak Predictors

    DEFF Research Database (Denmark)

    Lukas, Manuel; Hillebrand, Eric

    Relations between economic variables can often not be exploited for forecasting, suggesting that predictors are weak in the sense that estimation uncertainty is larger than bias from ignoring the relation. In this paper, we propose a novel bagging predictor designed for such weak predictor variab...

  17. Development of a fast pin-by-pin transport solver in ARCADIA registered

    International Nuclear Information System (INIS)

    Geemert, R. van

    2009-01-01

    For satisfaction of future global customer needs, dedicated efforts are being coordinated internationally and pursued continuously at AREVA NP. The currently ongoing CONVERGENCE project is committed to the development of the ARCADIA registered next generation core simulation software package. ARCADIA registered will be put to global use by all AREVA NP business regions, for the entire spectrum of core design processes, licensing computations and safety studies. As part of the currently ongoing trend towards more sophisticated neutronics methodologies, an SP 3 nodal transport concept (van Geemert 2008) has been developed for ARTEMIS (Hobson 2008) which is the steady-state and transient core simulation part of ARCADIA registered . For enabling a high computational performance, the SP 3 calculations are accelerated by applying multi-level coarse mesh rebalancing (van Geemert 2006). In the current implementation, SP 3 is typically about 1.4 times as expensive computationally as SP 1 (diffusion). The developed SP 3 solution concept is foreseen as the future computational workhorse for many-group 3D pin-by-pin full core computations by ARCADIA registered . With the entire numerical workload being highly parallelizable through domain decomposition techniques, associated CPU-time requirements that adhere to the efficiency needs in the nuclear industry can be expected to become feasible in the near future. The accuracy enhancement obtainable by using SP 3 instead of SP 1 has been verified by a detailed comparison of ARTEMIS 16-group pin-by-pin SP N results with KAERI's DeCart reference results (Kozlowski 2003) for the 2D pin-by-pin Purdue UO 2 /MOX benchmark. Within the associated pin-by-pin grid, large pin-to-pin variations in cross-section values occur due to the explicit modelling of guide tubes, gadolinium pins as well as the heterogeneous distribution of MOX assemblies and UO 2 assemblies featuring significantly different burnups. With a pin-by-pin grid as

  18. PINS Testing and Modification for Explosive Identification

    International Nuclear Information System (INIS)

    Seabury, E.H.; Caffrey, A.J.

    2011-01-01

    The INL's Portable Isotopic Neutron Spectroscopy System (PINS)1 non-intrusively identifies the chemical fill of munitions and sealed containers. PINS is used routinely by the U.S. Army, the Defense Threat Reduction Agency, and foreign military units to determine the contents of munitions and other containers suspected to contain explosives, smoke-generating chemicals, and chemical warfare agents such as mustard and nerve gas. The objects assayed with PINS range from softball-sized M139 chemical bomblets to 200 gallon DOT 500X ton containers. INL had previously examined2 the feasibility of using a similar system for the identification of explosives, and based on this proof-of-principle test, the development of a dedicated system for the identification of explosives in an improvised nuclear device appears entirely feasible. INL has been tasked by NNSA NA-42 Render Safe Research and Development with the development of such a system.

  19. Peripheral pin alignment system for fuel assemblies

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1981-01-01

    An alignment system is provided for nuclear fuel assemblies in a nuclear core. The core support structure of the nuclear reactor includes upwardly pointing alignment pins arranged in a square grid and engage peripheral depressions formed in the lateral periphery of the lower ends of each of the fuel assemblies of the core. In a preferred embodiment, the depressions are located at the corners of the fuel assemblies so that each depression includes one-quarter of a cylindrical void. Accordingly, each fuel assembly is positioned and aligned by one-quarter of four separate alignment pins which engage the fuel assemblies at their lower exterior corners. (author)

  20. Pinning, flux diodes and ratchets for vortices interacting with conformal pinning arrays

    International Nuclear Information System (INIS)

    Olson Reichhardt, C. J.; Wang, Y. L.; Argonne National Laboratory; Xiao, Z. L.; Northern Illinois University, DeKalb, IL

    2016-01-01

    A conformal pinning array can be created by conformally transforming a uniform triangular pinning lattice to produce a new structure in which the six-fold ordering of the original lattice is conserved but where there is a spatial gradient in the density of pinning sites. Here we examine several aspects of vortices interacting with conformal pinning arrays and how they can be used to create a flux flow diode effect for driving vortices in different directions across the arrays. Under the application of an ac drive, a pronounced vortex ratchet effect occurs where the vortices flow in the easy direction of the array asymmetry. When the ac drive is applied perpendicular to the asymmetry direction of the array, it is possible to realize a transverse vortex ratchet effect where there is a generation of a dc flow of vortices perpendicular to the ac drive due to the creation of a noise correlation ratchet by the plastic motion of the vortices. We also examine vortex transport in experiments and compare the pinning effectiveness of conformal arrays to uniform triangular pinning arrays. In conclusion, we find that a triangular array generally pins the vortices more effectively at the first matching field and below, while the conformal array is more effective at higher fields where interstitial vortex flow occurs.

  1. Electro-weak theory

    International Nuclear Information System (INIS)

    Deshpande, N.G.

    1980-01-01

    By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given

  2. Design of a terahertz CW photomixer based on PIN and superlattice PIN devices

    DEFF Research Database (Denmark)

    Krozer, Viktor; Eichhorn, Finn

    2006-01-01

    We present the design of a photomixer LO based on standard and superlattice PIN diodes, operating at 1 THz. The design is based on a direct integration of a double slot antenna with the PIN device and a suitable matching circuit. The antenna has been designed together with a dielectric lens using...... Ansoft HFSS EM simulation. The large-signal PIN diode model employed in the work has been improved compared to our previously developed model presented earlier in a 3 THz design. We demonstrate that the antenna characteristic changes drastically with the device in place....

  3. Tapered leaf support pin for operating plant guide tubes

    International Nuclear Information System (INIS)

    Land, J.T.; Hopkins, R.J.; Ford, D.E.

    1991-01-01

    This patent describes a mounting system for removably mounting the lower flange of a control rod guide tube over an opening in the upper core plate of a nuclear reactor comprising at least one elongated support pin mounted on the guide tube lower flange and resiliently receivable in a bore formed in the upper core plate. It comprises a support pin having a longitudinal axis and comprising a first pin portion mountable on the guide tube lower flange, and a second pin portion receivable within the upper core plate bore, the second pin portion including a solid body section adjacent the first pin portion and having an outer diameter which is accommodated by the bore by a close clearance fit; locking means mounted on the first pin portion of the support pin for retaining the guide tube lower flange between the solid body section of the second pin portion and the locking means; and a washer disposed around the first pin portion between the locking means and the control rod guide tube flange, the washer and the locking means including mutually engaging rounded surfaces for eliminating bending moments and stresses on the support pin during mounting of the locking means on the first pin portion of the support pin

  4. Weak interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model

  5. Vortex distribution in amorphous Mo{sub 80}Ge{sub 20} plates with artificial pinning center

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hitoshi [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Huy, Ho Thanh [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Physics and Electronics, University of Sciences, Vietnam National University HCMC, 227 Nguyen Van Cu, District 5, HoChiMinh City (Viet Nam); Miyoshi, Hiroki; Okamoto, Takuto; Dang, Vu The [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Kato, Masaru [Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Mathematical Science, Osaka Prefecture University1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Ishida, Takekazu, E-mail: ishida@center.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan)

    2016-11-15

    Highlights: • We reveal that the vortex distribution in small amorphous Mo{sub 80}Ge{sub 20} superconducting starshaped plate by using a scanning SQUID microscope. • We find that vortex configuration evolves systematically when the applied magnetic field is changed at the several different fields. • We fabricate an artificial dip by Ar ion milling in a mesoscopic plate, and find this works as a pinning center by comparing the vortex behavior in a sample without pins. - Abstract: Vortices in superconductor give rise to a rich variety of phenomena because they interact with shielding currents, temperature gradients, sample defects, boundaries, and other neighboring vortices. It would be very important to understand particular features of vortex states in a downsized system. Our study focuses on vortex states in small star-shaped Mo{sub 80}Ge{sub 20} plates with and without an artificial pin at the plate center. Vortex states are greatly influenced by the sample geometry, the temperature and the magnetic field, and they can be occasionally exotic compared to the bulk case. We use the amorphous Mo{sub 80}Ge{sub 20} films due to the nature of weak pinning in studying vortex configurations. We applied scanning superconducting quantum interference device (SQUID) microscopy because it enables us to see vortex states directly and it is the most sensitive instrument for mapping tiny local current flows or magnetic moments without damaging the sample. We interpreted that vortex configurations had essentially the nature of mirror reflection symmetry in both cases with an artificial pin and without an artificial pin and pinned cases while the influence of disorder was seen in our observation on the specimen without an artificial pin.

  6. History of Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  7. Hunting the weak bosons

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The possibility of the production of weak bosons in the proton-antiproton colliding beam facilities which are currently being developed, is discussed. The production, decay and predicted properties of these particles are described. (W.D.L.).

  8. Cladding properties under simulated fuel pin transients

    International Nuclear Information System (INIS)

    Hunter, C.W.; Johnson, G.D.

    1975-01-01

    A description is given of the HEDL fuel pin testing program utilizing a recently developed Fuel Cladding Transient Tester (FCTT) to generate the requisite mechanical property information on irradiated and unirradiated fast reactor fuel cladding under temperature ramp conditions. The test procedure is described, and data are presented

  9. Turban pin aspiration: new fashion, new syndrome.

    Science.gov (United States)

    Ilan, Ophir; Eliashar, Ron; Hirshoren, Nir; Hamdan, Kasem; Gross, Menachem

    2012-04-01

    Turban pin aspiration syndrome is a new clinical entity afflicting young Islamic girls wearing a turban.The goal of this study was to present our experience in diagnosis and treatment of this new entity, define its clinical and epidemiologic features, and shed a new light on the role of fashion in the increased incidence. A retrospective study in a tertiary university hospital. Review of clinical parameters and epidemiologic features of 26 patients diagnosed with turban pin aspiration syndrome admitted to the Hadassah-Hebrew University Hospitals in Jerusalem from 1990 to 2010. All patients were Muslim females with an average age of 16 years. In all cases, the history was positive for accidental aspiration. Most of the pins were located in the trachea (42%). In 20 cases, the pins were extracted by rigid bronchoscopy without major complications. Fluoroscopy-assisted rigid bronchoscopy was used successfully in three cases. In one case, the object was self-ejected by coughing before the bronchoscopy, and two patients were referred to the chest unit for thoracotomy. Clinicians should be aware of this distinct form of foreign body aspiration, its method of diagnosis, and extraction techniques. A cultural investigation showed a difference in the turban-fastening technique of young girls as compared with their mothers. Removal by rigid bronchoscopy is a safe method with a high success rate and should be considered as the preferred extraction method of choice. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  10. Radiographic examination methods for fuel pins

    International Nuclear Information System (INIS)

    Smirnov, V.P.; Dvoretskii, V.G.

    1987-11-01

    To study the fast neutron reactor fuel pins structure the NIIAR Institute used x diffraction, neutronic radiography and autoradiographies. The two first methods are used for internal macrostructure studies, the third method for the plutonium and uranium radial distribution. These methods and the main results are indicated in this document [fr

  11. Physicist pins hopes on particle collider

    CERN Multimedia

    2007-01-01

    Physicist pins hopes on particle collider By Deseret Morning News Published: Monday, Dec. 31, 27 12:4 a.m. MST FONT Scott Thomas, a 187 State University graduate, is working at the frontiers of science. The theoretical physicist is crafting ways to extract fundamental secrets that seem certain to be uncovered by the Large Hadron Collider.

  12. Charged weak currents

    International Nuclear Information System (INIS)

    Turlay, R.

    1979-01-01

    In this review of charged weak currents I shall concentrate on inclusive high energy neutrino physics. There are surely still things to learn from the low energy weak interaction but I will not discuss it here. Furthermore B. Tallini will discuss the hadronic final state of neutrino interactions. Since the Tokyo conference a few experimental results have appeared on charged current interaction, I will present them and will also comment on important topics which have been published during the last past year. (orig.)

  13. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  14. Analytical method for reconstruction pin to pin of the nuclear power density distribution

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Paulo O.; Silva, Fernando C.; Martinez, Aquilino S., E-mail: ppessoa@con.ufrj.br, E-mail: fernando@con.ufrj.br, E-mail: aquilino@imp.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    An accurate and efficient method for reconstructing pin to pin of the nuclear power density distribution, involving the analytical solution of the diffusion equation for two-dimensional neutron energy groups in homogeneous nodes, is presented. The boundary conditions used for analytic as solution are the four currents or fluxes on the surface of the node, which are obtained by Nodal Expansion Method (known as NEM) and four fluxes at the vertices of a node calculated using the finite difference method. The analytical solution found is the homogeneous distribution of neutron flux. Detailed distributions pin to pin inside a fuel assembly are estimated by the product of homogeneous flux distribution by local heterogeneous form function. Furthermore, the form functions of flux and power are used. The results obtained with this method have a good accuracy when compared with reference values. (author)

  15. Analytical method for reconstruction pin to pin of the nuclear power density distribution

    International Nuclear Information System (INIS)

    Pessoa, Paulo O.; Silva, Fernando C.; Martinez, Aquilino S.

    2013-01-01

    An accurate and efficient method for reconstructing pin to pin of the nuclear power density distribution, involving the analytical solution of the diffusion equation for two-dimensional neutron energy groups in homogeneous nodes, is presented. The boundary conditions used for analytic as solution are the four currents or fluxes on the surface of the node, which are obtained by Nodal Expansion Method (known as NEM) and four fluxes at the vertices of a node calculated using the finite difference method. The analytical solution found is the homogeneous distribution of neutron flux. Detailed distributions pin to pin inside a fuel assembly are estimated by the product of homogeneous flux distribution by local heterogeneous form function. Furthermore, the form functions of flux and power are used. The results obtained with this method have a good accuracy when compared with reference values. (author)

  16. PROCOPE, Collision Probability in Pin Clusters and Infinite Rod Lattices

    International Nuclear Information System (INIS)

    Amyot, L.; Daolio, C.; Benoist, P.

    1984-01-01

    1 - Nature of physical problem solved: Calculation of directional collision probabilities in pin clusters and infinite rod lattices. 2 - Method of solution: a) Gauss integration of analytical expressions for collision probabilities. b) alternately, an approximate closed expression (not involving integrals) may be used for pin-to-pin interactions. 3 - Restrictions on the complexity of the problem: number of fuel pins must be smaller than 62; maximum number of groups of symmetry is 300

  17. Optimization study on pin tip diameter of an impact-pin nozzle at high pressure ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, C. Palani; Lee, Kwon Hee [FMTRC, Daejoo Machinery Co. Ltd., Daegu (Korea, Republic of); Park, Tae Choon; Cha, Bong Jun [Engine Components Research Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Kim, Heuy Dong [Dept. of Mechanical Engineering, Andong National University, Andong (Korea, Republic of)

    2016-09-15

    Wet compression system is typically installed in a gas turbine engine to increase the net power output and efficiency. A crucial component of the wet compression system is the nozzle which generates fine water droplets for injection into the compressor. The main objective of present work is to optimize a kind of nozzle called impact-pin spray nozzle and thereby produce better quality droplets. To achieve this, the dynamics occurring in the water jet impinging on the pin tip, the subsequent formation of water sheet, which finally breaks into water droplets, must be studied. In this manuscript, the progress on the numerical studies on impact-pin nozzle are reported. A small computational domain covering the orifice, pin tip and the region where primary atomization occurs is selected for numerical analysis. The governing equations are selected in three dimensional cartesian form and simulations are performed to predict the dynamics of water jet impinging on the pin. Systematic studies were carried out and the results leading to the choice of turbulence model and the effect of pin tip diameter are reported here. Further studies are proposed to show the future directions of the present research work.

  18. A physico-genetic module for the polarisation of auxin efflux carriers PIN-FORMED (PIN)

    Science.gov (United States)

    Hernández-Hernández, Valeria; Barrio, Rafael A.; Benítez, Mariana; Nakayama, Naomi; Romero-Arias, José Roberto; Villarreal, Carlos

    2018-05-01

    Intracellular polarisation of auxin efflux carriers is crucial for understanding how auxin gradients form in plants. The polarisation dynamics of auxin efflux carriers PIN-FORMED (PIN) depends on both biomechanical forces as well as chemical, molecular and genetic factors. Biomechanical forces have shown to affect the localisation of PIN transporters to the plasma membrane. We propose a physico-genetic module of PIN polarisation that integrates biomechanical, molecular, and cellular processes as well as their non-linear interactions. The module was implemented as a discrete Boolean model and then approximated to a continuous dynamic system, in order to explore the relative contribution of the factors mediating PIN polarisation at the scale of single cell. Our models recovered qualitative behaviours that have been experimentally observed and enable us to predict that, in the context of PIN polarisation, the effects of the mechanical forces can predominate over the activity of molecular factors such as the GTPase ROP6 and the ROP-INTERACTIVE CRIB MOTIF-CONTAINING PROTEIN RIC1.

  19. Primary hip spica with crossed retrograde intramedullary rush pins ...

    African Journals Online (AJOL)

    Bursitis and penetration of pins at the site of Rush pin insertion is a complication associated with this method of treatment. Conclusion: Closed reduction and internal fixation with crossed Rush pins was a superior treatment method in terms of early weight bearing and restoration of normal anatomy. Keywords: Femoral ...

  20. Some aspects of continuum physics used in fuel pin modeling

    International Nuclear Information System (INIS)

    Bard, F.E.

    1975-06-01

    The mathematical formulation used in fuel pin modeling is described. Fuel pin modeling is not a simple extension of the experimental and interpretative methods used in classical mechanics. New concepts are needed to describe materials in a reactor environment. Some aspects of continuum physics used to develop these new constitutive equations for fuel pins are presented. (U.S.)

  1. Post irradiation examination on test fuel pins for PWR

    International Nuclear Information System (INIS)

    Fogaca Filho, N.; Ambrozio Filho, F.

    1981-01-01

    Certain aspects of irradiation technology on test fuel pins for PWR, are studied. The results of post irradiation tests, performed on test fuel pins in hot cells, are presented. The results of the tests permit an evaluation of the effects of irradiation on the fuel and cladding of the pin. (Author) [pt

  2. Advanced control system for the Integral Fast Reactor fuel pin processor

    International Nuclear Information System (INIS)

    Lau, L.D.; Randall, P.F.; Benedict, R.W.; Levinskas, D.

    1993-01-01

    A computerized control system has been developed for the remotely-operated fuel pin processor used in the Integral Fast Reactor Program, Fuel Cycle Facility (FCF). The pin processor remotely shears cast EBR- reactor fuel pins to length, inspects them for diameter, straightness, length, and weight, and then inserts acceptable pins into new sodium-loaded stainless-steel fuel element jackets. Two main components comprise the control system: (1) a programmable logic controller (PLC), together with various input/output modules and associated relay ladder-logic associated computer software. The PLC system controls the remote operation of the machine as directed by the OCS, and also monitors the machine operation to make operational data available to the OCS. The OCS allows operator control of the machine, provides nearly real-time viewing of the operational data, allows on-line changes of machine operational parameters, and records the collected data for each acceptable pin on a central data archiving computer. The two main components of the control system provide the operator with various levels of control ranging from manual operation to completely automatic operation by means of a graphic touch screen interface

  3. Temperature and pinning strength dependence of the critical current of a superconductor with a square periodic array of pinning sites

    International Nuclear Information System (INIS)

    Benkraouda, M.; Obaidat, I.M.; Al Khawaja, U.

    2006-01-01

    We have conducted extensive series of molecular dynamic simulations on driven vortex lattices interacting with periodic square arrays of pinning sites. In solving the over damped equation of vortex motion we took into account the vortex-vortex repulsion interaction, the attractive vortex-pinning interaction, and the driving Lorentz force at several values of temperature. We have studied the effect of varying the driving Lorentz force and varying the pinning strength on the critical current for several pinning densities, and temperature values. We have found that the pinning strength play an important role in enhancing the critical current over the whole temperature range. At low temperatures, the critical current was found to increase linearly with increasing the pinning strengths for all pinning densities. As the temperature increases, the effect of small pinning strengths diminishes and becomes insignificant at high temperatures

  4. Microstructure of irradiated Inconel 706 fuel pin cladding

    International Nuclear Information System (INIS)

    Yang, W.J.S.; Makenas, B.J.

    1983-08-01

    A fuel pin from the HEDL-P-60 experiment with a cladding of solution-annealed Inconel 706 breached in an apparently brittle manner at a position 12.7 cm above the bottom of the fuel column with a crack of 5.72 cm in length after 5.0 atomic percent burnup in EBR-II. Temperatures (time-averaged midwall) and fast fluences for the fractured area range from 447 0 C and 5.5 x 10 22 n/cm 2 to 526 0 C and 6.1 x 10 22 n/cm 2 (E > 0.1 MeV). Specimens of the fractured fuel pin section were successfully prepared and examined in both a scanning electron microscope and a transmission electron microscope. The fracture surfaces of the breached section showed brittle intergranular fracture characteristics for both the axial and circumferential cracks. Formation of γ' in the matrix near the breach confirmed that the irradiation temperature at the breached area was below 500 0 C, in agreement with other estimates of the temperature for the area, 447 to 526 0 C. A hexagonal eta-phase, Ni 3 (Ti,Nb), precipitated at boundaries near the breach. A more extensive eta-phase coating at grain boundaries was found in a section irradiated at 650 0 C. The eta-phase plates at grain boundaries are expected to have a detrimental effect on alloy ductility. A plane of weakness in this region along the (111) slip planes will develop in Inconel 706 because the eta-plates have a (111) habit relationship with the matrix

  5. Modeling the instability behavior of thin film devices: Fermi Level Pinning

    Science.gov (United States)

    Moeini, Iman; Ahmadpour, Mohammad; Gorji, Nima E.

    2018-05-01

    We investigate the underlying physics of degradation/recovery of a metal/n-CdTe Schottcky junction under reverse or forward bias stressing conditions. We used Sah-Noyce-Shockley (SNS) theory to investigate if the swept of Fermi level pinning at different levels (under forward/reverse bias) is the origin of change in current-voltage characteristics of the device. This theory is based on Shockley-Read-Hall recombination within the depletion width and takes into account the interface defect levels. Fermi Level Pinning theory was primarily introduced by Ponpon and developed to thin film solar cells by Dharmadasa's group in Sheffield University-UK. The theory suggests that Fermi level pinning at multiple levels occurs due to high concentration of electron-traps or acceptor-like defects at the interface of a Schottky or pn junction and this re-arranges the recombination rate and charage collection. Shift of these levels under stress conditions determines the change in current-voltage characteristics of the cell. This theory was suggested for several device such as metal/n-CdTe, CdS/CdTe, CIGS/CdS or even GaAs solar cells without a modeling approach to clearly explain it's physics. We have applied the strong SNS modeling approach to shed light on Fermi Level Pinning theory. The modeling confirms that change in position of Fermi Level and it's pining in a lower level close to Valence band increases the recombination and reduces the open-circuit voltage. In contrast, Fermi Level pinning close to conduction band strengthens the electric field at the junction which amplifies the carrier collection and boosts the open-circuit voltage. This theory can well explain the stress effect on device characteristics of various solar cells or Schottky junctions by simply finding the right Fermi level pinning position at every specific stress condition.

  6. Pinning impulsive synchronization of stochastic delayed coupled networks

    International Nuclear Information System (INIS)

    Tang Yang; Fang Jian-An; Wong W K; Miao Qing-Ying

    2011-01-01

    In this paper, the pinning synchronization problem of stochastic delayed complex network (SDCN) is investigated by using a novel hybrid pinning controller. The proposed hybrid pinning controller is composed of adaptive controller and impulsive controller, where the two controllers are both added to a fraction of nodes in the network. Using the Lyapunov stability theory and the novel hybrid pinning controller, some sufficient conditions are derived for the exponential synchronization of such dynamical networks in mean square. Two numerical simulation examples are provided to verify the effectiveness of the proposed approach. The simulation results show that the proposed control scheme has a fast convergence rate compared with the conventional adaptive pinning method. (general)

  7. Advances in high-field superconducting composites by addition of artificial pinning centres to niobium-titanium

    International Nuclear Information System (INIS)

    Cooley, L.D.; Motowidlo, L.R.

    1999-01-01

    Artificial pinning-centre (APC) niobium-titanium composites attain critical current density J c values higher than 4000 A mm -2 at 5 T, 4.2 K, surpassing the barrier reached by the conventional Nb-Ti composite process. At 2 T APC composites achieve more than double the J c of conventional composites, making them particularly well suited for low-field applications. On the other hand, APC composites are inferior to conventional composites at 8 T, due to weak high-field pinning and reduced upper critical field. This review discusses fabrication techniques, microstructural development and superconducting and flux-pinning properties of APC composites. Key elements and underlying issues for achieving higher J c are identified and discussed in terms of the current state of the art. (author)

  8. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

    1990-01-01

    New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

  9. Magnetic studies of current conduction and flux pinning in high-Tc cuprates: Virgin, irradiated, and oxygen deficient materials

    International Nuclear Information System (INIS)

    Thompson, J.R.; Civale, L.; Marwick, A.D.; Holtzberg, F.

    1992-09-01

    To increase the current density and pinning of magnetic flux in high temperature superconductors, defects with point-like and line-like geometries were created in controlled numbers using ion irradiation methods. Single crystals of Y 1 Ba 2 Cu 3 O 7 and Bi 2 Sr 2 Ca 1 Cu 2 0 8 superconductors were studied using dc magnetic methods. These studies showed greatly increased irreversibility in the vortex state magnetization and enhanced intragrain current density J c following irradiation. Linear defects, created by irradiation with energetic heavy ions, are particularly effective in pinning vortices at higher temperatures and magnetic fields. Further investigations of ''flux creep'' (the time dependence of magnetization) are well described by recent vortex glass and collective pinning theories. Complementary investigations have delineated the role of oxygen deficiency δ on pinning in aligned Y 1 Ba 2 Cu 3 O 7-δ materials

  10. Microstructure and Pinning Properties of Hexagonal Disc Shaped Single Crystalline MgB2

    Energy Technology Data Exchange (ETDEWEB)

    Patel, J. R.

    2003-04-30

    We synthesized hexagonal-disc-shaped MgB{sub 2} single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from X-ray micro-diffraction showed the crystal symmetry of MgB{sub 2}. A thorough crystallographic mapping within a single crystal showed that the edge and c-axis of hexagonal-disc shape exactly matched the (10-10) and the (0001) directions of the MgB{sub 2} phase. Thus, these well-shaped single crystals may be the best candidates for studying the direction dependences of the physical properties. The magnetization curve and the magnetic hysteresis for these single crystals showed the existence of a wide reversible region and weak pinning properties, which supported our single crystals being very clean.

  11. Weakening of flux-pinning strength for high-Tc superconductors in an alternating magnetic field

    International Nuclear Information System (INIS)

    Chen, Q.Y.

    1992-01-01

    This paper reports on the flux-pinning forces in high temperature superconductors which were found to be weakened in an ac field as the applied field strength or the frequency increases. In the weakly pinned regime, flux dynamics could be described with the concept of magnetic diffusion. Flux-motion-induced finite resistivity could lead to significant skin-effect which was reflected in the ac screening effectiveness. The frequency dependence of the relative local field within a superconducting hollow cylinder were used to deduce the flux-motion resistivity ρ. For superconducting YB 2 Cu 3 O 7 - x compounds at 77K it was found that ρ ∼(mu, Omega)-cm. The corresponding magnetic diffusion coefficient was ∼ 224 cm 2 /s. At 750 Hz the skin depth is around 1.54 mm as compared with the 2-mm sample wall thickness

  12. Microstructure and pinning properties of hexagonal-disc shaped single crystalline MgB2

    Science.gov (United States)

    Jung, C. U.; Kim, J. Y.; Chowdhury, P.; Kim, Kijoon H.; Lee, Sung-Ik; Koh, D. S.; Tamura, N.; Caldwell, W. A.; Patel, J. R.

    2002-11-01

    We synthesized hexagonal-disc-shaped MgB2 single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from x-ray micro-diffraction showed the crystal symmetry of MgB2. A thorough crystallographic mapping within a single crystal showed that the edge and c axis of hexagonal-disc shape exactly matched the [101¯0] and the [0001] directions of the MgB2 phase. Thus, these well-shaped single crystals may be the best candidates for studying the direction dependences of the physical properties. The magnetization curve and the magnetic hysteresis curve for these single crystals showed the existence of a wide reversible region and weak pinning properties, which supported our single crystals being very clean.

  13. The pin pixel detector--neutron imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Rhodes, N J; Schooneveld, E M; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a neutron gas pixel detector intended for application in neutron diffraction studies is reported. Using standard electrical connector pins as point anodes, the detector is based on a commercial 100 pin connector block. A prototype detector of aperture 25.4 mmx25.4 mm has been fabricated, giving a pixel size of 2.54 mm which matches well to the spatial resolution typically required in a neutron diffractometer. A 2-Dimensional resistive divide readout system has been adapted to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics. The timing properties of the device match well to the requirements of the ISIS-pulsed neutron source.

  14. Elementary pinning force for a superconducting vortex

    International Nuclear Information System (INIS)

    Hyun, O.B.; Finnemore, D.K.; Schwartzkopf, L.; Clem, J.R.

    1987-01-01

    The elementary pinning force f/sub p/ has been measured for a single vortex trapped in one of the superconducting layers of a cross-strip Josephson junction. At temperatures close to the transition temperature the vortex can be pushed across the junction by a transport current. The vortex is found to move in a small number of discrete steps before it exits the junction. The pinning force for each site is found to be asymmetric and to have a value of about 10/sup -6/ N/m at the reduced temperature, t = T/T/sub c/ = 0.95. As a function of temperature, f/sub p/ is found to vary approximately as (1-t)/sup 3/2/. .AE

  15. Top-nozzle mounted replacement guide pin assemblies

    International Nuclear Information System (INIS)

    Gilmore, C.B.; Andrews, W.H.

    1993-01-01

    A replacement guide pin assembly is provided for aligning a nuclear fuel assembly with an upper core plate of a nuclear reactor core. The guide pin assembly includes a guide pin body having a radially expandable base insertable within a hole in the top nozzle, a ferrule insertable within the guide pin base and capable of imparting a radially and outwardly directed force on the expandable base to expand it within the hole of the top nozzle and thereby secure the guide pin body to the top nozzle in response to a predetermined displacement of the ferrule relative to the guide pin body along its longitudinal axis, and a lock screw interfitted with the ferrule and threaded into the guide pin body so as to produce the predetermined displacement of the ferrule. (author)

  16. Timing analysis of PWR fuel pin failures

    International Nuclear Information System (INIS)

    Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J.; Straka, M.

    1992-09-01

    Research has been conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B ampersand W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin bumup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PFL/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B ampersand W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B ampersand W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design bumup. Using peaking factors commensurate widi actual bumups would result in longer intervals for both reactor designs. This document also contains appendices A through J of this report

  17. Startpoints via weak contractions

    OpenAIRE

    Agyingi, Collins Amburo; Gaba, Yaé Ulrich

    2018-01-01

    Startpoints (resp. endpoints) can be defined as "oriented fixed points". They arise naturally in the study of fixed for multi-valued maps defined on quasi-metric spaces. In this article, we give a new result in the startpoint theory for quasi-pseudometric spaces. The result we present is obtained via a generalized weakly contractive set-valued map.

  18. Weakly Coretractable Modules

    Science.gov (United States)

    Hadi, Inaam M. A.; Al-aeashi, Shukur N.

    2018-05-01

    If R is a ring with identity and M is a unitary right R-module. Here we introduce the class of weakly coretractable module. Some basic properties are investigated and some relationships between these modules and other related one are introduced.

  19. Performance measurements of hybrid PIN diode arrays

    International Nuclear Information System (INIS)

    Jernigan, J.G.; Arens, J.F.; Collins, T.; Herring, J.; Shapiro, S.L.; Wilburn, C.D.

    1990-05-01

    We report on the successful effort to develop hybrid PIN diode arrays and to demonstrate their potential as components of vertex detectors. Hybrid pixel arrays have been fabricated by the Hughes Aircraft Co. by bump bonding readout chips developed by Hughes to an array of PIN diodes manufactured by Micron Semiconductor Inc. These hybrid pixel arrays were constructed in two configurations. One array format having 10 x 64 pixels, each 120 μm square, and the other format having 256 x 256 pixels, each 30 μm square. In both cases, the thickness of the PIN diode layer is 300 μm. Measurements of detector performance show that excellent position resolution can be achieved by interpolation. By determining the centroid of the charge cloud which spreads charge into a number of neighboring pixels, a spatial resolution of a few microns has been attained. The noise has been measured to be about 300 electrons (rms) at room temperature, as expected from KTC and dark current considerations, yielding a signal-to-noise ratio of about 100 for minimum ionizing particles. 4 refs., 13 figs

  20. Applicability of the diffusion and simplified P3 theories for BWR pin-by-pin core analysis

    International Nuclear Information System (INIS)

    Tada, Kenichi; Yamamoto, Akio; Kitamura, Yasunori; Yamane, Yoshihiro; Watanabe, Masato; Noda, Hiroshi

    2007-01-01

    The pin-by-pin fine mesh core calculation method is considered as a candidate of next-generation core calculation method for BWR. In this study, the diffusion and the simplified P 3 (SP 3 ) theories are applied to the pin-by-pin core analysis of BWR. Performances of the diffusion and the SP 3 theories for cell-homogeneous pin-by-pin fine mesh BWR core analysis are evaluated through comparison with cell-heterogeneous detailed transport calculation by the method of characteristics (MOC). In this study, two-dimensional, 2x2 multi-assemblies geometry is used to compare the prediction accuracies of the diffusion and the SP 3 theories. The 2x2 multi- assemblies geometry consists of two types of 9x9 UO 2 assembly that have two different enrichment splittings. To mitigate the cell-homogenization error, the SPH method is applied for the pin-by-pin fine mesh calculation. The SPH method is a technique that reproduces a result of heterogeneous calculation by that of homogeneous calculation. The calculation results indicated that diffusion theory shows larger discrepancy than that of SP 3 theory on pin-wise fission rates. Furthermore, the accuracy of the diffusion theory would not be sufficient for the pin-by-pin fine mesh calculation. In contrast to the diffusion theory, the SP 3 theory shows much better accuracy on pin wise fission rates. Therefore, if the SP 3 theory is applied, the accuracy of the pin-by-pin fine mesh BWR core analysis will be higher and will be sufficient for production calculation. (author)

  1. Model of Ni-63 battery with realistic PIN structure

    Science.gov (United States)

    Munson, Charles E.; Arif, Muhammad; Streque, Jeremy; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim; El Gmili, Youssef; Salvestrini, Jean-Paul; Voss, Paul L.; Ougazzaden, Abdallah

    2015-09-01

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  2. Model of Ni-63 battery with realistic PIN structure

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah, E-mail: aougazza@georgiatech-metz.fr [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, 30332-0250 Atlanta (United States); Arif, Muhammad; Salvestrini, Jean-Paul [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Université de Lorraine, CentraleSupélec, LMOPS, EA 4423, 2 rue E. Belin, 57070 Metz (France); Streque, Jeremy; El Gmili, Youssef [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim [Laboratory for Photonics and Nanostructures, CNRS, Route de Nozay, 91460 Marcoussis (France)

    2015-09-14

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  3. Pins and posters: Paradigms for content publication on situated displays.

    Science.gov (United States)

    José, Rui; Pinto, Hélder; Silva, Bruno; Melro, Ana

    2013-01-01

    Public-display systems are still far from being a medium for meeting people's diverse communication goals. Moving toward open displays will require publication paradigms that can overcome the challenges of meaningful engagement and enable users to fully understand and control the publication process. The metaphors of pins and posters have inspired two complementary paradigms for public displays. Researchers implemented these paradigms in the Instant Places system, which they deployed on 10 displays in diverse urban locations for six months. They collected user and system data regarding the users' practices. The findings improve the understanding of what might drive user-generated content in networks of urban displays. Such knowledge can inform the design of tools and procedures for situated publication in public displays.

  4. Model of Ni-63 battery with realistic PIN structure

    International Nuclear Information System (INIS)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah; Arif, Muhammad; Salvestrini, Jean-Paul; Streque, Jeremy; El Gmili, Youssef; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim

    2015-01-01

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination

  5. Introduction to weak interactions

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    An account is first given of the electromagnetic interactions of complex, scalar, vector and spinor fields. It is shown that the electromagnetic field may be considered as a gauge field. Yang-Mills fields and the field theory invariant with respect to the non-Abelian gauge transformation group are then described. The construction, owing to this invariance principle, of conserved isospin currents associated with gauge fields is also demonstrated. This is followed by a historical survey of the development of the weak interaction theory, established at first to describe beta disintegration processes by analogy with electrodynamics. The various stages are mentioned from the discovery of principles and rules and violation of principles, such as those of invariance with respect to spatial reflection and charge conjugation to the formulation of the effective current-current Lagrangian and research on the structure of weak currents [fr

  6. Weak states and security

    OpenAIRE

    Rakipi, Albert

    2006-01-01

    Cataloged from PDF version of article. Although the weak 1 failing states have often been deseribed as the single most important problem for the international order s ince the en d of Cold W ar (F .Fukuyaına 2004:92) several dimensions of this phenomenon still remain unexplored. While this phenomenon has been present in the international politics even earlier, only the post Cold W ar period accentuated its relationship with security issues. Following the Cold W ar' s "peacef...

  7. Composite weak bosons

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.

    1988-04-01

    Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

  8. Survival and weak chaos.

    Science.gov (United States)

    Nee, Sean

    2018-05-01

    Survival analysis in biology and reliability theory in engineering concern the dynamical functioning of bio/electro/mechanical units. Here we incorporate effects of chaotic dynamics into the classical theory. Dynamical systems theory now distinguishes strong and weak chaos. Strong chaos generates Type II survivorship curves entirely as a result of the internal operation of the system, without any age-independent, external, random forces of mortality. Weak chaos exhibits (a) intermittency and (b) Type III survivorship, defined as a decreasing per capita mortality rate: engineering explicitly defines this pattern of decreasing hazard as 'infant mortality'. Weak chaos generates two phenomena from the normal functioning of the same system. First, infant mortality- sensu engineering-without any external explanatory factors, such as manufacturing defects, which is followed by increased average longevity of survivors. Second, sudden failure of units during their normal period of operation, before the onset of age-dependent mortality arising from senescence. The relevance of these phenomena encompasses, for example: no-fault-found failure of electronic devices; high rates of human early spontaneous miscarriage/abortion; runaway pacemakers; sudden cardiac death in young adults; bipolar disorder; and epilepsy.

  9. A proposed parameterization of interface discontinuity factors depending on neighborhood for pin-by-pin diffusion computations for LWR

    International Nuclear Information System (INIS)

    Herrero, Jose Javier; Garcia-Herranz, Nuria; Ahnert, Carol

    2011-01-01

    There exists an interest in performing full core pin-by-pin computations for present nuclear reactors. In such type of problems the use of a transport approximation like the diffusion equation requires the introduction of correction parameters. Interface discontinuity factors can improve the diffusion solution to nearly reproduce a transport solution. Nevertheless, calculating accurate pin-by-pin IDF requires the knowledge of the heterogeneous neutron flux distribution, which depends on the boundary conditions of the pin-cell as well as the local variables along the nuclear reactor operation. As a consequence, it is impractical to compute them for each possible configuration. An alternative to generate accurate pin-by-pin interface discontinuity factors is to calculate reference values using zero-net-current boundary conditions and to synthesize afterwards their dependencies on the main neighborhood variables. In such way the factors can be accurately computed during fine-mesh diffusion calculations by correcting the reference values as a function of the actual environment of the pin-cell in the core. In this paper we propose a parameterization of the pin-by-pin interface discontinuity factors allowing the implementation of a cross sections library able to treat the neighborhood effect. First results are presented for typical PWR configurations. (author)

  10. A proposed parameterization of interface discontinuity factors depending on neighborhood for pin-by-pin diffusion computations for LWR

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, Jose Javier; Garcia-Herranz, Nuria; Ahnert, Carol, E-mail: herrero@din.upm.es, E-mail: nuria@din.upm.es, E-mail: carol@din.upm.es [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid (Spain)

    2011-07-01

    There exists an interest in performing full core pin-by-pin computations for present nuclear reactors. In such type of problems the use of a transport approximation like the diffusion equation requires the introduction of correction parameters. Interface discontinuity factors can improve the diffusion solution to nearly reproduce a transport solution. Nevertheless, calculating accurate pin-by-pin IDF requires the knowledge of the heterogeneous neutron flux distribution, which depends on the boundary conditions of the pin-cell as well as the local variables along the nuclear reactor operation. As a consequence, it is impractical to compute them for each possible configuration. An alternative to generate accurate pin-by-pin interface discontinuity factors is to calculate reference values using zero-net-current boundary conditions and to synthesize afterwards their dependencies on the main neighborhood variables. In such way the factors can be accurately computed during fine-mesh diffusion calculations by correcting the reference values as a function of the actual environment of the pin-cell in the core. In this paper we propose a parameterization of the pin-by-pin interface discontinuity factors allowing the implementation of a cross sections library able to treat the neighborhood effect. First results are presented for typical PWR configurations. (author)

  11. Genome-wide identification and evolution of the PIN-FORMED (PIN) gene family in Glycine max.

    Science.gov (United States)

    Liu, Yuan; Wei, Haichao

    2017-07-01

    Soybean (Glycine max) is one of the most important crop plants. Wild and cultivated soybean varieties have significant differences worth further investigation, such as plant morphology, seed size, and seed coat development; these characters may be related to auxin biology. The PIN gene family encodes essential transport proteins in cell-to-cell auxin transport, but little research on soybean PIN genes (GmPIN genes) has been done, especially with respect to the evolution and differences between wild and cultivated soybean. In this study, we retrieved 23 GmPIN genes from the latest updated G. max genome database; six GmPIN protein sequences were changed compared with the previous database. Based on the Plant Genome Duplication Database, 18 GmPIN genes have been involved in segment duplication. Three pairs of GmPIN genes arose after the second soybean genome duplication, and six occurred after the first genome duplication. The duplicated GmPIN genes retained similar expression patterns. All the duplicated GmPIN genes experienced purifying selection (K a /K s genome sequence of 17 wild and 14 cultivated soybean varieties. Our research provides useful and comprehensive basic information for understanding GmPIN genes.

  12. Robustness of pinning a general complex dynamical network

    International Nuclear Information System (INIS)

    Wang Lei; Sun Youxian

    2010-01-01

    This Letter studies the robustness problem of pinning a general complex dynamical network toward an assigned synchronous evolution. Several synchronization criteria are presented to guarantee the convergence of the pinning process locally and globally by construction of Lyapunov functions. In particular, if a pinning strategy has been designed for synchronization of a given complex dynamical network, then no matter what uncertainties occur among the pinned nodes, synchronization can still be guaranteed through the pinning. The analytical results show that pinning control has a certain robustness against perturbations on network architecture: adding, deleting and changing the weights of edges. Numerical simulations illustrated by scale-free complex networks verify the theoretical results above-acquired.

  13. Is magnetic pinning a dominant mechanism in Nb-Ti

    International Nuclear Information System (INIS)

    Cooley, L.D.; Lee, P.J.; Larbalestier, D.C.

    1991-01-01

    In this paper, the authors compare the pinning behavior of an artificial pinning center (APC) composite and a nanometer-filament Nb 46.5 wt% Ti composite to that of a conventional Nb 48 wt% Ti composite. The microstructure of the APC composite resembles the conventional composite, where ribbons of normal metal form the pinning centers, whereas the nanometer-filament composite has no internal normal metal but pins instead at the filament surface. The APC composite exhibits much stronger pinning relative to B c 2 than the conventional composite (21.4 GN/m 3 , 7 T vs. 18.9 GN/m 3 , 11 T), which is possibly due to the increased amount of pinning center (50 vol.% vs. 25 vol.%), however the proximity effect reduces the B c 2 unfavorably

  14. Ferromagnetic artificial pinning centers in multifilamentary superconducting wires

    International Nuclear Information System (INIS)

    Wang, J.Q.; Rizzo, N.D.; Prober, D.E.

    1997-01-01

    The authors fabricated multifilamentary NbTi wires with ferromagnetic (FM) artificial pinning centers (APCs) to enhance the critical current density (J c ) in magnetic fields. They used a bundle and draw technique to process the APC wires with either Ni or Fe as the pinning centers. Both wires produced higher J c in the high field range (5-9 T) than previous non-magnetic APC wires similarly processed, even though the authors have not yet optimized pin percentage. Using a magnetometer they found that the pins remained ferromagnetic for the wires with maximum J c . However, they did observe a substantial loss of FM material for the wires where the pin diameter approached 3 nm. Thus, they expect further enhancement of J c with better pin quality

  15. Correlation of creep and swelling with fuel pin performance

    International Nuclear Information System (INIS)

    Jackson, R.J.; Washburn, D.F.; Garner, F.A.; Gilbert, E.R.

    1975-09-01

    The HEDL PNL-11 experiment described was one in a series of fueled subassemblies irradiated in EBR-II to demonstrate the adequacy of the FFTF fuel pin design. The cladding material, dimensions, and fuel density are prototypic of FFTF. Because neutron flux in EBR-II is lower than in FFTF, the uranium enrichment is higher in these experimental fuel pins, irradiated in EBR-II, than the FFTF enrichment for comparable linear heat rates. Some pertinent oprating conditions for the center fuel pin in this experiment are listed. This 37-pin subassembly represents, at 110,000 MWd/MTM, the highest burnup yet attained by a prototypic FFTF subassembly. Similarly, this is the highest fluence presently attained by prototypic fuel pins. A cladding breach occurred in one fuel pin which is presently being examined. Results are presented and discussed

  16. Analysis of three idealized reactor configurations: plate, pin, and homogeneous

    International Nuclear Information System (INIS)

    McKnight, R.D.

    1983-01-01

    Detailed Monte Carlo calculations have been performed for three distinct configurations of an idealized fast critical assembly. This idealized assembly was based on the LMFBR benchmark critical assembly ZPR-6/7. In the first configuration, the entire core was loaded with the plate unit cell of ZPR-6/7. In the second configuration, the entire core was loaded with the ZPR sodium-filled pin calandria. The actual ZPR pin calandria are loaded with mixed (U,Pu) oxide pins which closely match the composition of the ZPR-6/7 plate unit cell. For the present study, slight adjustments were made in the atom concentrations and the length of the pin calandria in order to make the core boundaries and average composition for the pin-cell configuration identical to those of the plate-cell configuration. In the third configuration, the core was homogeneous, again with identical core boundaries and average composition as the plate and pin configurations

  17. Analytic models for fuel pin transient performance

    International Nuclear Information System (INIS)

    Bard, F.E.; Fox, G.L.; Washburn, D.F.; Hanson, J.E.

    1976-09-01

    HEDL's ability to analyze various mechanisms that operate within a fuel pin has progressed substantially through development of codes such as PECTCLAD, which solves cladding response, and DSTRESS, which solves fuel response. The PECTCLAD results show good correlation with a variety of mechanical tests on cladding material and also demonstrate the significance of cladding strength when applying the life fraction rule. The DSTRESS results have shown that fuel deforms sufficiently during overpower transient tests that available volumes are filled, whether in the form of a central cavity or start-up cracks

  18. Optimum Prestress of Tanks with Pinned Base

    DEFF Research Database (Denmark)

    Brøndum-Nielsen, Troels

    1998-01-01

    Amin Ghali and Eleanor Elliott presented in their paper an interesting suggestion for prestressing of circular tanks without sliding joints. For many prestressed tanks the following construction procedure is adopted:In order to ensure compressive hoop forces in the wall near the base, the wall...... is allowed to slide freely in the radial direction during tensioning (free base).After tensioning such displacements are prevented (pinned base). The present paper addresses the problem of prestress of such tanks.Keywords: circular prestressing; creep properties; prestressed concrete; redistribution...

  19. On the obstructions to non-Cliffordian pin structures

    Energy Technology Data Exchange (ETDEWEB)

    Chamblin, A. (Dept. of Applied Maths and Theoretical Physics, Univ. of Cambridge (United Kingdom))

    1994-07-01

    We derive the topological obstructions to the existence of non-Cliffordian pin structures on four-dimensional spacetimes. We apply these obstructions to the study of non-Cliffordian pin-Lorentz cobordism. We note that our method of derivation applies equally well in any dimension and in any signature, and we present a general format for calculating obstructions in these situations. Finally, we interpret the breakdown of pin structure and discuss the relevance of this to aspects of physics. (orig.)

  20. Sodium erosion of boron carbide from breached absorber pins

    International Nuclear Information System (INIS)

    Basmajian, J.A.; Baker, D.E.

    1981-03-01

    The purpose of the irradiation experiment was to provide an engineering demonstration of the irradiation behavior of breached boron carbide absorber pins. By building defects into the cladding of prototypic absorber pins, and performing the irradiation under typical FFTF operating conditions, a qualitative assessment of the consequences of a breach was achieved. Additionally, a direct comparison of pin behavior with that of the ex-reactor test could be made

  1. Hypernuclear weak decay puzzle

    International Nuclear Information System (INIS)

    Barbero, C.; Horvat, D.; Narancic, Z.; Krmpotic, F.; Kuo, T.T.S.; Tadic, D.

    2002-01-01

    A general shell model formalism for the nonmesonic weak decay of the hypernuclei has been developed. It involves a partial wave expansion of the emitted nucleon waves, preserves naturally the antisymmetrization between the escaping particles and the residual core, and contains as a particular case the weak Λ-core coupling formalism. The extreme particle-hole model and the quasiparticle Tamm-Dancoff approximation are explicitly worked out. It is shown that the nuclear structure manifests itself basically through the Pauli principle, and a very simple expression is derived for the neutron- and proton-induced decays rates Γ n and Γ p , which does not involve the spectroscopic factors. We use the standard strangeness-changing weak ΛN→NN transition potential which comprises the exchange of the complete pseudoscalar and vector meson octets (π,η,K,ρ,ω,K * ), taking into account some important parity-violating transition operators that are systematically omitted in the literature. The interplay between different mesons in the decay of Λ 12 C is carefully analyzed. With the commonly used parametrization in the one-meson-exchange model (OMEM), the calculated rate Γ NM =Γ n +Γ p is of the order of the free Λ decay rate Γ 0 (Γ NM th congruent with Γ 0 ) and is consistent with experiments. Yet the measurements of Γ n/p =Γ n /Γ p and of Γ p are not well accounted for by the theory (Γ n/p th p th > or approx. 0.60Γ 0 ). It is suggested that, unless additional degrees of freedom are incorporated, the OMEM parameters should be radically modified

  2. Cell homogenization methods for pin-by-pin core calculations tested in slab geometry

    International Nuclear Information System (INIS)

    Yamamoto, Akio; Kitamura, Yasunori; Yamane, Yoshihiro

    2004-01-01

    In this paper, performances of spatial homogenization methods for fuel or non-fuel cells are compared in slab geometry in order to facilitate pin-by-pin core calculations. Since the spatial homogenization methods were mainly developed for fuel assemblies, systematic study of their performance for the cell-level homogenization has not been carried out. Importance of cell-level homogenization is recently increasing since the pin-by-pin mesh core calculation in actual three-dimensional geometry, which is less approximate approach than current advanced nodal method, is getting feasible. Four homogenization methods were investigated in this paper; the flux-volume weighting, the generalized equivalence theory, the superhomogenization (SPH) method and the nonlinear iteration method. The last one, the nonlinear iteration method, was tested as the homogenization method for the first time. The calculations were carried out in simplified colorset assembly configurations of PWR, which are simulated by slab geometries, and homogenization performances were evaluated through comparison with the reference cell-heterogeneous calculations. The calculation results revealed that the generalized equivalence theory showed best performance. Though the nonlinear iteration method can significantly reduce homogenization error, its performance was not as good as that of the generalized equivalence theory. Through comparison of the results obtained by the generalized equivalence theory and the superhomogenization method, important byproduct was obtained; deficiency of the current superhomogenization method, which could be improved by incorporating the 'cell-level discontinuity factor between assemblies', was clarified

  3. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson , P

    1996-01-01

    This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.

  4. On Weak Markov's Principle

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich Wilhelm

    2002-01-01

    We show that the so-called weak Markov's principle (WMP) which states that every pseudo-positive real number is positive is underivable in E-HA + AC. Since allows one to formalize (atl eastl arge parts of) Bishop's constructive mathematics, this makes it unlikely that WMP can be proved within...... the framework of Bishop-style mathematics (which has been open for about 20 years). The underivability even holds if the ine.ective schema of full comprehension (in all types) for negated formulas (in particular for -free formulas) is added, which allows one to derive the law of excluded middle...

  5. Weak interaction rates

    International Nuclear Information System (INIS)

    Sugarbaker, E.

    1995-01-01

    I review available techniques for extraction of weak interaction rates in nuclei. The case for using hadron charge exchange reactions to estimate such rates is presented and contrasted with alternate methods. Limitations of the (p,n) reaction as a probe of Gamow-Teller strength are considered. Review of recent comparisons between beta-decay studies and (p,n) is made, leading to cautious optimism regarding the final usefulness of (p,n)- derived GT strengths to the field of astrophysics. copyright 1995 American Institute of Physics

  6. Trending on Pinterest: an examination of pins about skin tanning.

    Science.gov (United States)

    Banerjee, Smita C; Rodríguez, Vivian M; Greene, Kathryn; Hay, Jennifer L

    2018-04-10

    Rates of melanoma and nonmelanoma skin cancers are on the rise in the USA with data revealing disproportionate increase in female young adults. The popularity of intentional skin tanning among U.S. adolescents is attributed to several factors, including prioritization of physical appearance, media images of tanned celebrities, ease of availability of artificial tanning facilities, and more recently, the prevalence and celebration of tanned skin on social media. Pinterest, as the third most popular social media platform, was searched for "pins" about skin tanning. The resultant "pins" were examined to understand the extent and characteristics of skin tanning portrayed on Pinterest. We analyzed pins on Pinterest about skin tanning (n = 501) through a quantitative content analysis. Overall, results indicated an overwhelmingly protanning characteristic of pins about skin tanning on Pinterest, with over 85% of pins promoting tanning behavior. The pins were generally characterized by the portrayal of a female subject (61%) and provided positive reinforcement for tanning (49%). Use of tanning for enhancing appearance was the main positive outcome expectancy portrayed in the pins (35%), and nudity or exposure of skin on arms (32%) and legs (31%) was evident in about a third of pins. With overwhelmingly positive pins promoting tanning, use of female subjects, exhibiting nudity, and appearance enhancement, there seems be to a consistent targeting of female users to accept tanning as a socially acceptable and popular behavior. The findings indicate a need for developing sun protection messages and the leveraging of social media for dissemination of skin cancer prevention and detection messages.

  7. The pin pixel detector--X-ray imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a soft X-ray gas pixel detector, which uses connector pins for the anodes is reported. Based on a commercial 100 pin connector block, a prototype detector of aperture 25.4 mm centre dot 25.4 mm can be economically fabricated. The individual pin anodes all show the expected characteristics of small gas detectors capable of counting rates reaching 1 MHz per pin. A 2-dimensional resistive divide readout system has been developed to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics.

  8. Reconstruction calculation of pin power for ship reactor core

    International Nuclear Information System (INIS)

    Li Haofeng; Shang Xueli; Chen Wenzhen; Wang Qiao

    2010-01-01

    Aiming at the limitation of the software that pin power distribution for ship reactor core was unavailable, the calculation model and method of the axial and radial pin power distribution were proposed. Reconstruction calculations of pin power along axis and radius was carried out by bicubic and bilinear interpolation and cubic spline interpolation, respectively. The results were compared with those obtained by professional reactor physical soft with fine mesh difference. It is shown that our reconstruction calculation of pin power is simple and reliable as well as accurate, which provides an important theoretic base for the safety analysis and operating administration of the ship nuclear reactor. (authors)

  9. ITP Hanford Type 40 pin electrical connector failure analysis

    International Nuclear Information System (INIS)

    Imrich, K.J.

    1993-01-01

    Corrosion products observed on the ITP Hanford Type 40 pin electrical connectors would be expected to adversely affect the power and control signals supplied to process equipment in the filter cell by the connectors. Corrosion products were consistent with those found on similar pins in DWPF. The recommendations based on the findings in this investigation are as follows: (1) Replace male and female rhodium plated pins with gold plated pins. (2) Replace the galvanized carbon steel spring on the male connector with a stainless steel spring. (3) Install protective caps over Hanford connectors when jumpers are removed

  10. Fuel-pin cladding transient failure strain criterion

    International Nuclear Information System (INIS)

    Bard, F.E.; Duncan, D.R.; Hunter, C.W.

    1983-01-01

    A criterion for cladding failure based on accumulated strain was developed for mixed uranium-plutonium oxide fuel pins and used to interpret the calculated strain results from failed transient fuel pin experiments conducted in the Transient Reactor Test (TREAT) facility. The new STRAIN criterion replaced a stress-based criterion that depends on the DORN parameter and that incorrectly predicted fuel pin failure for transient tested fuel pins. This paper describes the STRAIN criterion and compares its prediction with those of the stress-based criterion

  11. Dynamic Phases of Vortices in Superconductors with Periodic Pinning

    International Nuclear Information System (INIS)

    Reichhardt, C.; Olson, C.; Nori, F.

    1997-01-01

    We present results from extensive simulations of driven vortex lattices interacting with periodic arrays of pinning sites. Changing an applied driving force produces a rich variety of novel dynamical plastic flow phases which are very distinct from those observed in systems with random pinning arrays. Signatures of the transition between these different dynamical phases include sudden jumps in the current-voltage curves as well as marked changes in the vortex trajectories and vortex lattice order. Several dynamical phase diagrams are obtained as a function of commensurability, pinning strength, and spatial order of the pinning sites. copyright 1997 The American Physical Society

  12. Positioning and locking device for fuel pin to grid attachment

    International Nuclear Information System (INIS)

    Frick, T.M.; Wineman, A.L.

    1976-01-01

    A positioning and locking device for fuel pin to grid attachment provides an inexpensive means of positively positioning and locking the individual fuel pins which make up the driver fuel assemblies used in nuclear reactors. The device can be adapted for use with a currently used attachment grid assembly design and insures that the pins remain in their proper position throughout the in-reactor life of the assembly. This device also simplifies fuel bundle assembly in that a complete row of fuel pins can be added to the bundle during each step of assembly. 8 claims, 8 drawing figures

  13. Heat transfer in a fuel pin shipping container

    International Nuclear Information System (INIS)

    Ingham, J.G.

    1980-01-01

    Maximum cladding temperatures occur when the IDENT 1578 fuel pin shipping container is installed in the T-3 Cask. The maximum allowable cladding temperature of 800 0 F is reached when the rate of energy deposited in the 19-pin basket reaches 400 watts. Since 45% of the energy which is generated in the fuel escapes the 19-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 400/.55 = 727 watts. Similarly, the maximum allowable cladding temperature of 800 0 F is reached when the rate of energy deposited in the 40-pin basket reaches 465 watts. Since 33% of the energy which is generated in the fuel escapes the 40-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 465/.66 = 704 watts. The IDENT 1578 fuel pin shipping container therefore meets its thermal design criteria. IDENT 1578 can handle fuel pins with a decay heat load of 600 watts while maintaining the maximum fuel pin cladding temperature below 800 0 F. The emissivities which were determined from the test results for the basket tubes and container are relatively low and correspond to new, shiny conditions. As the IDENT 1578 container is exposed to high temperatures for extended periods of time during the transportation of fuel pins, the emissivities will probably increase. This will result in reduced temperatures

  14. Nano-engineered pinning centres in YBCO superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A., E-mail: adrian.crisan@infim.ro [National Institute for Materials Physics Bucharest, 105 bis Atomistilor Str., 077125 Magurele (Romania); School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Dang, V.S. [School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Nano and Energy Center, VNU Hanoi University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi (Viet Nam); Mikheenko, P. [School of Metallurgy and Materials, University of Birmingham, Edgbaston, B15 2TT Birmingham (United Kingdom); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)

    2017-02-15

    Highlights: • Power applications of YBCO films/coated conductors in technological relevant magnetic fields requires nano-engineered pinning centre. • Three approaches have been proposed: substrate decoration, quasi-multilayers, and targets with secondary phase nano-inclusions. • Combination of all three approaches greatly increased critical current in YBCO films. • Bulk pinning force, pinning potential, and critical current density are estimated and discussed in relation with the type and strength of pinning centres related to the defects evidenced by Transmission Electron Microscopy. - Abstract: For practical applications of superconducting materials in applied magnetic fields, artificial pinning centres in addition to natural ones are required to oppose the Lorentz force. These pinning centres are actually various types of defects in the superconductor matrix. The pinning centres can be categorised on their dimension (volume, surface or point) and on their character (normal cores or Δκ cores). Different samples have been produced by Pulsed Laser Deposition, with various thicknesses, temperatures and nanostructured additions to the superconducting matrix. They have been characterized by SQUID Magnetic Properties Measurement System and Physical Properties Measurement System, as well as by Transmission Electron Microscopy (TEM). Correlations between pinning architecture, TEM images, and critical currents at various fields and field orientations will be shown for a large number of YBa{sub 2}Cu{sub 3}O{sub x} films with various types and architectures of artificial pinning centres.

  15. FABRICE process for the refrabrication of experimental pins in a hot cell, from pins pre-irradiated in power reactors

    International Nuclear Information System (INIS)

    Vignesoult, N.; Atabek, R.; Ducas, S.

    1982-06-01

    The Fabrice ''hot cell refabrication'' process for small pins from very long irradiated fuel elements was developed at the CEA to allow parametric studies of the irradiation behavior of pins from nuclear power plants. Since this operation required complete assurance of the validity of the process, qualification of the fabrication was performed on test pins, refabricated in the hot cell, as well as irradiation qualification. The latter qualification was intended to demonstrate that, in identical experimental irradiation conditions, the refabricated Fabrice pins behaved in the same way as whole pins with the same initial characteristics. This qualification of the Fabrice process, dealing with more than twenty pins at different burnups, showed that fabrication did not alter: the inherent characteristics of the sampled fuel element and the irradiation behavior of the sampled fuel element [fr

  16. Weakly Supervised Dictionary Learning

    Science.gov (United States)

    You, Zeyu; Raich, Raviv; Fern, Xiaoli Z.; Kim, Jinsub

    2018-05-01

    We present a probabilistic modeling and inference framework for discriminative analysis dictionary learning under a weak supervision setting. Dictionary learning approaches have been widely used for tasks such as low-level signal denoising and restoration as well as high-level classification tasks, which can be applied to audio and image analysis. Synthesis dictionary learning aims at jointly learning a dictionary and corresponding sparse coefficients to provide accurate data representation. This approach is useful for denoising and signal restoration, but may lead to sub-optimal classification performance. By contrast, analysis dictionary learning provides a transform that maps data to a sparse discriminative representation suitable for classification. We consider the problem of analysis dictionary learning for time-series data under a weak supervision setting in which signals are assigned with a global label instead of an instantaneous label signal. We propose a discriminative probabilistic model that incorporates both label information and sparsity constraints on the underlying latent instantaneous label signal using cardinality control. We present the expectation maximization (EM) procedure for maximum likelihood estimation (MLE) of the proposed model. To facilitate a computationally efficient E-step, we propose both a chain and a novel tree graph reformulation of the graphical model. The performance of the proposed model is demonstrated on both synthetic and real-world data.

  17. Material accountancy for metallic fuel pin casting

    International Nuclear Information System (INIS)

    Bucher, R.G.; Orechwa, Y.; Beitel, J.C.

    1995-01-01

    The operation of the Fuel Conditioning Facility (FCF) is based on the electrometallurgical processing of spent metallic reactor fuel. The pin casting operation, although only one of several operations in FCF, was the first to be on-line. As such, it has served to demonstrate the material accountancy system in many of its facets. This paper details, for the operation of the pin casting process with depleted uranium, the interaction between the mass tracking system (MTG) and some of the ancillary computer codes which generate pertinent information for operations and material accountancy. It is necessary to distinguish between two types of material balance calculations -- closeout for operations and material accountancy for safeguards. The two have much in common, for example, the mass tracking system database and the calculation of an inventory difference, but, in general, are not congruent with regard to balance period and balance spatial domain. Moreover, the objective, assessment, and reporting requirements of the calculated inventory difference are very different in the two cases

  18. The Egyptian Hair Pin: practical, sacred, fatal

    Directory of Open Access Journals (Sweden)

    Joann Fletcher

    2016-11-01

    Full Text Available Generally regarded as little more than a mundane tool employed in daily life, the humble hairpin occasionally played a rather more prominent role in history than has perhaps been appreciated. As the most ancient implements associated with hair styling, simple pins of bone and ivory were commonly employed in Egypt by c.4000 BC as a means of securing long hair in an upswept style (e.g. Petrie and Mace 1901, 21, 34. Although their occasional use by men undermines the assumption that hairpins are 'a relatively certain example of a “gendered” artefact' (Wilfong 1997, 67, the vast majority have been found in female burials. They can be made of bone and ivory, wood, steatite, glass, gold, silver and bronze, and two 12cm long bronze examples were found within the hair of Princess Ahmosi c.1550 BC (Fletcher 1995, 376, 441 while the hair of an anonymous woman at Gurob c.AD 110 had been secured in a bun with pins of bone, tortoiseshell and silver (Walker and Bierbrier 1997, 209.

  19. Method and device for cleaning fuel pins

    International Nuclear Information System (INIS)

    Matsumoto, Kaname; Oohigashi, Yoshiaki.

    1985-01-01

    Purpose: To remove clads or scales deposited on the outer surface of fuel pins in BWR type reactors. Method: A fuel assembly taken out of a reactor core is vertically contained without detaching a channel box in a scrubber tower disposed in a liquid tight manner within a fuel pool. Then, a specifically prepared slurry is caused to flow and uprise from the bottom of the scrubber tower into the channel box and then discharged from the top of the tower. The slurry is prepared by mixing pure water and granules (for example, as activated carbon, ion exchanger resin, iron and molecular sieve) of such a granular size as not causing clogging in the channel box of the fuel assembly and having a larger specific gravity than pure water. The slurry flown into the channel box scrubs the surface of fuel pins to scrape off clads or scales. Then, discharged slurry is sent to a hydraulic cyclone to separate the granules from the clads or scales. (Ikeda, J.)

  20. Lightning Pin Injection Testing on MOSFETS

    Science.gov (United States)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.; Koppen, Sandra V.; Mielnik, John J.; Vaughan, Roger K.; Wysocki, Philip F.; Celaya, Jose R.; Saha, Sankalita

    2009-01-01

    Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.

  1. An Upgrade Pinning Block: A Mechanical Practical Aid for Fast Labelling of the Insect Specimens.

    Science.gov (United States)

    Ghafouri Moghaddam, Mohammad Hossein; Ghafouri Moghaddam, Mostafa; Rakhshani, Ehsan; Mokhtari, Azizollah

    2017-01-01

    A new mechanical innovation is described to deal with standard labelling of dried specimens on triangular cards and/or pinned specimens in personal and public collections. It works quickly, precisely, and easily and is very useful for maintaining label uniformity in collections. The tools accurately sets the position of labels in the shortest possible time. This tools has advantages including rapid processing, cost effectiveness, light weight, and high accuracy, compared to conventional methods. It is fully customisable, compact, and does not require specialist equipment to assemble. Conventional methods generally require locating holes on the pinning block surface when labelling with a resulting risk to damage of the specimens. Insects of different orders can be labelled by this simple and effective tool.

  2. Fast reactor fuel pin behaviour modelling in the UK

    International Nuclear Information System (INIS)

    Matthews, J.R.; Hughes, H.

    1979-01-01

    Two fuel behaviour codes have been applied extensively to fast reactor problems; SLEUTH developed at Sprlngfields Nuclear Laboratory and FRUMP at A.E.R.E. Harwell. The SLEUTH fuel pin endurance code was originally developed to define a programme of power cycling and power ramp experiments In Advanced Gas Cooled Reactors (AGRs) where, because of the very soft cladding, pellet clad interaction is severe. The code was required to define accelerated test conditions to generalise from the observed endurance to that under other power histories and to select for investigation the most significant design, material and operational variables. The weak clad and low coolant pressure combine to make fission gas swelling a major contributor to clad deformation while the high clad ductility renders the distribution of strain readily observable. This has led to a detailed study of strain concentrations using the SEER code. SLEUTH and SEER have subsequently been used to specify power cycling and power ramp 112 experiments in water cooled, fast and materials testing reactors with the aim of developing a unified quantitative model of pellet-clad interaction whatever the reactor system. The FRUMP fuel behaviour code was developed specifically for the interpretation of fast reactor fuel pin behaviour. Experience with earlier models was valuable In its development. Originally the model was developed to describe behaviour during normal operation, but subsequently the code has been used extensively in the field of accident studies. Much of the effort in FRUMP development has been devoted to the production of physical models of the various effects of irradiation and the temperature gradients on the structure of the fuel and clad. Each process is modelled as well as is permitted by current knowledge and the limitations of computing costs. Each sub-model has a form which reflects the underlying mechanisms, where quantities are unknown values are assigned semi-empirically, i.e. coefficients

  3. Fast reactor fuel pin behaviour modelling in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, J R [UKAEA, Harwell, Didcot, Oxon (United Kingdom); Hughes, H [Springfields Nuclear Power Development Laboratories, Springfields, Salwick, Preston (United Kingdom)

    1979-12-01

    Two fuel behaviour codes have been applied extensively to fast reactor problems; SLEUTH developed at Sprlngfields Nuclear Laboratory and FRUMP at A.E.R.E. Harwell. The SLEUTH fuel pin endurance code was originally developed to define a programme of power cycling and power ramp experiments In Advanced Gas Cooled Reactors (AGRs) where, because of the very soft cladding, pellet clad interaction is severe. The code was required to define accelerated test conditions to generalise from the observed endurance to that under other power histories and to select for investigation the most significant design, material and operational variables. The weak clad and low coolant pressure combine to make fission gas swelling a major contributor to clad deformation while the high clad ductility renders the distribution of strain readily observable. This has led to a detailed study of strain concentrations using the SEER code. SLEUTH and SEER have subsequently been used to specify power cycling and power ramp 112 experiments in water cooled, fast and materials testing reactors with the aim of developing a unified quantitative model of pellet-clad interaction whatever the reactor system. The FRUMP fuel behaviour code was developed specifically for the interpretation of fast reactor fuel pin behaviour. Experience with earlier models was valuable In its development. Originally the model was developed to describe behaviour during normal operation, but subsequently the code has been used extensively in the field of accident studies. Much of the effort in FRUMP development has been devoted to the production of physical models of the various effects of irradiation and the temperature gradients on the structure of the fuel and clad. Each process is modelled as well as is permitted by current knowledge and the limitations of computing costs. Each sub-model has a form which reflects the underlying mechanisms, where quantities are unknown values are assigned semi-empirically, i.e. coefficients

  4. BARS - a heterogeneous code for 3D pin-by-pin LWR steady-state and transient calculation

    International Nuclear Information System (INIS)

    Avvakumov, A.V.; Malofeev, V.M.

    2000-01-01

    A 3D pin-by-pin dynamic model for LWR detailed calculation was developed. The model is based on a coupling of the BARS neutronic code with the RELAP5/MOD3.2 thermal hydraulic code. This model is intended to calculate a fuel cycle, a xenon transient, and a wide range of reactivity initiated accidents in a WWER and a PWR. Galanin-Feinberg heterogeneous method was realized in the BARS code. Some results for a validation of the heterogeneous method are presented for reactivity coefficients, a pin-by-pin power distribution, and a fast pulse transient. (Authors)

  5. Pinning in BSCCO above the ordinary irreversibility line

    Science.gov (United States)

    Indenbom, M. V.; van der Beek, C. J.; Berseth, V.; Konczykowski, M.; Motohira, N.; Berger, H.; Benoit, W.

    1996-12-01

    Frequency-dependent observations of magnetic flux structures are used to show that pinning plays a principal role in the whole mixed state in Bi2Sr2CaCu2O8 (BSCCO) single crystals. We speculate that the random pinning force on the moving vortices may dominate over thermal fluctuations and considerably modify the position of the vortex lattice phase transition.

  6. Inscuteable Regulates the Pins-Mud Spindle Orientation Pathway

    Science.gov (United States)

    Mauser, Jonathon F.; Prehoda, Kenneth E.

    2012-01-01

    During asymmetric cell division, alignment of the mitotic spindle with the cell polarity axis ensures that the cleavage furrow separates fate determinants into distinct daughter cells. The protein Inscuteable (Insc) is thought to link cell polarity and spindle positioning in diverse systems by binding the polarity protein Bazooka (Baz; aka Par-3) and the spindle orienting protein Partner of Inscuteable (Pins; mPins or LGN in mammals). Here we investigate the mechanism of spindle orientation by the Insc-Pins complex. Previously, we defined two Pins spindle orientation pathways: a complex with Mushroom body defect (Mud; NuMA in mammals) is required for full activity, whereas binding to Discs large (Dlg) is sufficient for partial activity. In the current study, we have examined the role of Inscuteable in mediating downstream Pins-mediated spindle orientation pathways. We find that the Insc-Pins complex requires Gαi for partial activity and that the complex specifically recruits Dlg but not Mud. In vitro competition experiments revealed that Insc and Mud compete for binding to the Pins TPR motifs, while Dlg can form a ternary complex with Insc-Pins. Our results suggest that Insc does not passively couple polarity and spindle orientation but preferentially inhibits the Mud pathway, while allowing the Dlg pathway to remain active. Insc-regulated complex assembly may ensure that the spindle is attached to the cortex (via Dlg) before activation of spindle pulling forces by Dynein/Dynactin (via Mud). PMID:22253744

  7. IMp: The customizable LEGO(®) Pinned Insect Manipulator.

    Science.gov (United States)

    Dupont, Steen; Price, Benjamin; Blagoderov, Vladimir

    2015-01-01

    We present a pinned insect manipulator (IMp) constructed of LEGO® building bricks with two axes of movement and two axes of rotation. In addition we present three variants of the IMp to emphasise the modular design, which facilitates resizing to meet the full range of pinned insect specimens, is fully customizable, collapsible, affordable and does not require specialist tools or knowledge to assemble.

  8. Cracking Bank PINs by Playing Mastermind

    Science.gov (United States)

    Focardi, Riccardo; Luccio, Flaminia L.

    The bank director was pretty upset noticing Joe, the system administrator, spending his spare time playing Mastermind, an old useless game of the 70ies. He had fought the instinct of telling him how to better spend his life, just limiting to look at him in disgust long enough to be certain to be noticed. No wonder when the next day the director fell on his chair astonished while reading, on the newspaper, about a huge digital fraud on the ATMs of his bank, with millions of Euros stolen by a team of hackers all around the world. The article mentioned how the hackers had 'played with the bank computers just like playing Mastermind', being able to disclose thousands of user PINs during the one-hour lunch break. That precise moment, a second before falling senseless, he understood the subtle smile on Joe's face the day before, while training at his preferred game, Mastermind.

  9. The lumped parameter model for fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W S [Ontario Hydro, Toronto, ON (Canada)

    1996-12-31

    The use of a lumped fuel-pin model in a thermal-hydraulic code is advantageous because of computational simplicity and efficiency. The model uses an averaging approach over the fuel cross section and makes some simplifying assumptions to describe the transient equations for the averaged fuel, fuel centerline and sheath temperatures. It is shown that by introducing a factor in the effective fuel conductivity, the analytical solution of the mean fuel temperature can be modified to simulate the effects of the flux depression in the heat generation rate and the variation in fuel thermal conductivity. The simplified analytical method used in the transient equation is presented. The accuracy of the lumped parameter model has been compared with the results from the finite difference method. (author). 4 refs., 2 tabs., 4 figs.

  10. Panoramic irradiator dose mapping with pin photodiodes

    International Nuclear Information System (INIS)

    Ferreira, Danilo Cardenuto; Napolitano, Celia Marina; Bueno, Carmen Cecilia

    2011-01-01

    In this work we study the possibility of using commercial silicon PIN photodiodes (Siemens, SFH 00206) for dose mapping in the Panoramic Irradiator facility at IPEN-CNEN/SP. The chosen photodiode, that is encased in 1.2 mm thickness polymer layer, displays promising dosimetric characteristics such as small size (sensitive area of 7.00 mm 2 ), high sensitivity and low dark current (≅ 300 pA, at 0 V) together with low-cost and wide availability. The Panoramic facility is an irradiator Type II with absorbed dose certificated by International Dose Assurance Service (IDAS) offered by the International Agency Energy Atomic (IAEA). The charge registered by the diode as a function of the absorbed dose was in excellent agreement with that one calibrated by IDAS. Besides this, the easy handling and fast response of the SFH00206 diode compared to Fricke chemical dosimeters encouraged us to perform dose mapping around the source. (author)

  11. Alpha particles spectrometer with photodiode PIN

    International Nuclear Information System (INIS)

    Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R.; Ramirez G, J.

    2009-10-01

    The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

  12. Effective augmentation of networked systems and enhancing pinning controllability

    Science.gov (United States)

    Jalili, Mahdi

    2018-06-01

    Controlling dynamics of networked systems to a reference state, known as pinning control, has many applications in science and engineering. In this paper, we introduce a method for effective augmentation of networked systems, while also providing high levels of pinning controllability for the final augmented network. The problem is how to connect a sub-network to an already existing network such that the pinning controllability is maximised. We consider the eigenratio of the augmented Laplacian matrix as a pinning controllability metric, and use graph perturbation theory to approximate the influence of edge addition on the eigenratio. The proposed metric can be effectively used to find the inter-network links connecting the disjoint networks. Also, an efficient link rewiring approach is proposed to further optimise the pinning controllability of the augmented network. We provide numerical simulations on synthetic networks and show that the proposed method is more effective than heuristic ones.

  13. Artificial pinning center technology to enhance vortex pinning in YBCO coated conductors

    International Nuclear Information System (INIS)

    Matsumoto, Kaname; Mele, Paolo

    2010-01-01

    Crystalline defects on the nano-scale, which are called artificial pinning centers (APCs), were successfully introduced into high-temperature superconductors (HTS) by nanotechnology, in order to strongly pin the quantized vortices. The critical current densities, J c , of the HTS films were dramatically improved by APCs. It is possible to form APCs in high-quality epitaxial films, keeping the desired dimensionality, volume fraction, spatial distribution and so on. The in-field J c of HTS films at 77 K was improved by one order of magnitude compared with previous values using APCs. This technology can be applied to the coated conductor technology in progress, and a high J c has already been reported. A current outline of the research is described in this review.

  14. Retractable Pin Tools for the Friction Stir Welding Process

    Science.gov (United States)

    1998-01-01

    Two companies have successfully commercialized a specialized welding tool developed at the Marshall Space Flight Center (MSFC). Friction stir welding uses the high rotational speed of a tool and the resulting frictional heat created from contact to crush, 'stir' together, and forge a bond between two metal alloys. It has had a major drawback, reliance on a single-piece pin tool. The pin is slowly plunged into the joint between two materials to be welded and rotated as high speed. At the end of the weld, the single-piece pin tool is retracted and leaves a 'keyhole,' something which is unacceptable when welding cylindrical objects such as drums, pipes and storage tanks. Another drawback is the requirement for different-length pin tools when welding materials of varying thickness. An engineer at the MSFC helped design an automatic retractable pin tool that uses a computer-controlled motor to automatically retract the pin into the shoulder of the tool at the end of the weld, preventing keyholes. This design allows the pin angle and length to be adjusted for changes in material thickness and results in a smooth hole closure at the end of the weld. Benefits of friction stir welding, using the MSFC retractable pin tool technology, include the following: The ability to weld a wide range of alloys, including previously unweldable and composite materials; provision of twice the fatigue resistance of fusion welds and no keyholes; minimization of material distortion; no creation of hazards such as welding fumes, radiation, high voltage, liquid metals, or arcing; automatic retraction of the pin at the end of the weld; and maintaining full penetration of the pin.

  15. Vortex pinning landscape in YBa2Cu3O7 films grown by hybrid liquid phase epitaxy

    International Nuclear Information System (INIS)

    Maiorov, B; Kursumovic, A; Stan, L; Zhou, H; Wang, H; Civale, L; Feenstra, R; MacManus-Driscoll, J L

    2007-01-01

    The influence of film thickness and growth rate on the vortex pinning in hybrid liquid phase epitaxy (HLPE) films was explored. Film growth rates as high as 12 nm s -1 (0.7 μm min -1 ) produced high J c films. Weak or no thickness dependence was found in films of thickness ranging from 0.4 to 3 μm. Field and angular measurements of the critical current density (J c ) and the power-law exponent (N) of the current-voltage curves were used to determine the nature of pinning. Films thinner than 0.6 μm showed a higher density of correlated defects parallel to the ab plane than thicker films. Using HLPE, it was possible to achieve very strong pinning in films ∼3 μm thick, yielding critical currents over 300 A cm -1 width at self-field, and as high as 35 A cm -1 width at μ 0 H = 3 T at T = 75.5 K. Decreasing the deposition rate allowed improving the high field performance, opening up the possibility to engineer the pinning landscape of the HLPE films

  16. Transport properties and pinning analysis for Co-doped BaFe2As2 thin films on metal tapes

    Science.gov (United States)

    Xu, Zhongtang; Yuan, Pusheng; Fan, Fan; Chen, Yimin; Ma, Yanwei

    2018-05-01

    We report on the transport properties and pinning analysis of BaFe1.84Co0.16As2 (Ba122:Co) thin films on metal tapes by pulsed laser deposition. The thin films exhibit a large in-plane misorientation of 5.6°, close to that of the buffer layer SrTiO3 (5.9°). Activation energy U 0(H) analysis reveals a power law relationship with field, having three different exponents at different field regions, indicative of variation from single-vortex pinning to a collective flux creep regime. The Ba122:Co coated conductors present {{T}{{c}}}{{onset}} = 20.2 K and {{T}{{c}}}{{zero}} = 19.0 K along with a self-field J c of 1.14 MA cm‑2 and an in-field J c as high as 0.98 and 0.86 MA cm‑2 up to 9 T at 4.2 K for both major crystallographic directions of the applied field, promising for high field applications. Pinning force analysis indicates a significant enhancement compared with similar Ba122:Co coated conductors. By using the anisotropic scaling approach, intrinsic pinning associated with coupling between superconducting blocks can be identified as the pinning source in the vicinity of H//ab, while for H//c random point defects are likely to play a role but correlated defects start to be active at high temperatures.

  17. Optimal pin enrichment distributions in nuclear reactor fuel bundles

    International Nuclear Information System (INIS)

    Lim, E.Y.

    1976-01-01

    A methodology has been developed to determine the fuel pin enrichment distribution that yields the best approximation to a prescribed power distribution in nuclear reactor fuel bundles. The problem is formulated as an optimization problem in which the optimal pin enrichments minimize the sum of squared deviations between the actual and prescribed fuel pin powers. A constant average enrichment constraint is imposed to ensure that a suitable value of reactivity is present in the bundle. When constraints are added that limit the fuel pins to a few enrichment types, one must determine not only the optimal values of the enrichment types but also the optimal distribution of the enrichment types amongst the pins. A matrix of boolean variables is used to describe the assignment of enrichment types to the pins. This nonlinear mixed integer programming problem may be rigorously solved with either exhaustive enumeration or branch and bound methods using a modification of the algorithm from the continuous problem as a suboptimization. Unfortunately these methods are extremely cumbersome and computationally overwhelming. Solutions which require only a moderate computational effort are obtained by assuming that the fuel pin enrichments in this problem are ordered as in the solution to the continuous problem. Under this assumption search schemes using either exhaustive enumeration or branch and bound become computationally attractive. An adaptation of the Hooke--Jeeves pattern search technique is shown to be especially efficient

  18. Roles of pinning strength and density in vortex melting

    International Nuclear Information System (INIS)

    Obaidat, I M; Khawaja, U Al; Benkraouda, M

    2008-01-01

    We have investigated the role of pinning strength and density on the equilibrium vortex-lattice to vortex-liquid phase transition under several applied magnetic fields. This study was conducted using a series of molecular dynamic simulations on several samples with different strengths and densities of pinning sites which are arranged in periodic square arrays. We have found a single solid-liquid vortex transition when the vortex filling factor n>1. We have found that, for fixed pinning densities and strengths, the melting temperature, T m , decreases almost linearly with increasing magnetic field. Our results provide direct numerical evidence for the significant role of both the strength and density of pinning centers on the position of the melting line. We have found that the vortex-lattice to vortex-liquid melting line shifts up as the pinning strength or the pinning density was increased. The effect on the melting line was found to be more pronounced at small values of strength and density of pinning sites

  19. Loss of Pin1 Suppresses Hedgehog-Driven Medulloblastoma Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Tao Xu

    2017-03-01

    Full Text Available Medulloblastoma is the most common malignant brain tumor in children. Therapeutic approaches to medulloblastoma (combination of surgery, radiotherapy, and chemotherapy have led to significant improvements, but these are achieved at a high cost to quality of life. Alternative therapeutic approaches are needed. Genetic mutations leading to the activation of the Hedgehog pathway drive tumorigenesis in ~30% of medulloblastoma. In a yeast two-hybrid proteomic screen, we discovered a novel interaction between GLI1, a key transcription factor for the mediation of Hedgehog signals, and PIN1, a peptidylprolyl cis/trans isomerase that regulates the postphosphorylation fate of its targets. The GLI1/PIN1 interaction was validated by reciprocal pulldowns using epitope-tagged proteins in HEK293T cells as well as by co-immunoprecipiations of the endogenous proteins in a medulloblastoma cell line. Our results support a molecular model in which PIN1 promotes GLI1 protein abundance, thus contributing to the positive regulation of Hedgehog signals. Most importantly, in vivo functional analyses of Pin1 in the GFAP-tTA;TRE-SmoA1 mouse model of Hedgehog-driven medulloblastoma demonstrate that the loss of Pin1 impairs tumor development and dramatically increases survival. In summary, the discovery of the GLI1/PIN1 interaction uncovers PIN1 as a novel therapeutic target in Hedgehog-driven medulloblastoma tumorigenesis.

  20. Fuel pin design algorithm for conceptual design studies

    International Nuclear Information System (INIS)

    Uselman, J.P.

    1979-01-01

    Two models are available which are currently verified by part of the requirements and which are adaptable as algorithms for the complete range. Fuel thermal performance is described by the HEDL SIEX model. Cladding damage and total deformation are determined by the GE GRO-II structural analysis code. A preliminary fuel pin performance model for analysis of (U, P/sub U/)O 2 pins in the COROPT core conceptual design system has been constructed by combining the key elements of SIEX and GRO-II. This memo describes the resulting pin performance model and its interfacing with COROPT system. Some exemplary results are presented

  1. Self-organized critical behavior in pinned flux lattices

    International Nuclear Information System (INIS)

    Pla, O.; Nori, F.

    1991-01-01

    We study the response of pinned fluxed lattices, under small perturbations in the driving force, below and close to the pinning-depinning transition. For driving Lorentz forces below F c (the depinning force at which the whole flux lattice slides), the system has instabilities against small force increases, with a power-law distribution characteristic of self-organized criticality. Specifically, D(d)∼d -1,3 , where d is the displacement of a flux line after a very small force increase. We also study the initial stages of the motion of the lattice once the driving force overcomes the pinning forces

  2. Study of PIN diode energy traps created by neutrons

    International Nuclear Information System (INIS)

    Sopko, V; Dammer, J; Sopko, B; Chren, D

    2013-01-01

    Characterization of radiation defects is still ongoing and finds greater application in the increasing radiation doses on semiconductor detectors in experiments. Studying the changes of silicon PIN diode for high doses of radiation is the fundamental motivation for our measurements. In this article we describe the behavior of the PIN diode and development of the disorder caused by neutrons from a 252Cf and doses up to 8 Gy. The calibration curve for PIN diode shows the effect of disorders as the changes of the voltampere characteristics depending on the dose of neutron irradiation. The measured values for defects are in good agreement with created energy traps.

  3. Fabrication of oxide dispersion strengthened ferritic clad fuel pins

    International Nuclear Information System (INIS)

    Zirker, L.R.; Bottcher, J.H.; Shikakura, S.; Tsai, C.L.

    1991-01-01

    A resistance butt welding procedure was developed and qualified for joining ferritic fuel pin cladding to end caps. The cladding are INCO MA957 and PNC ODS lots 63DSA and 1DK1, ferritic stainless steels strengthened by oxide dispersion, while the end caps are HT9 a martensitic stainless steel. With adequate parameter control the weld is formed without a residual melt phase and its strength approaches that of the cladding. This welding process required a new design for fuel pin end cap and weld joint. Summaries of the development, characterization, and fabrication processes are given for these fuel pins. 13 refs., 6 figs., 1 tab

  4. Inverse crystallization if Abrikosov vortex system at periodic pinning

    CERN Document Server

    Zyubin, M V; Kashurnikov, V A

    2002-01-01

    The vortex system in the quasi-two-dimensional HTSC plate is considered in the case of the periodic pinning. The M(H) magnetization curves by various values of the external magnetic field and different temperatures are calculated through the Monte Carlo method. It is shown that in the case of the periodic pinning the crystallization of the vortex system is possible by the temperature increase. A number of peculiarities conditioned by the impact of the pinning centers periodic lattice are identified on the magnetization curves. The pictures of the vortex distribution corresponding to various points on the M(H) curve are obtained

  5. Analyzing the use of pins in safety bearings

    DEFF Research Database (Denmark)

    da Fonseca, Cesar A. L. L.; Weber, Hans I.; Fleischer, Philip F.

    2015-01-01

    A new concept for safety bearings is analyzed: useful in emergency situations, it shall protect the bearing from destruction by the use of pins which impact with a disc, both capable of good energy dissipation. Results of work in progress are presented by validating partial stages......–Kutta method is validated with experimental results. Simulations of rotor orbits due to the impact condition are analyzed and compared to data obtained from the experiment giving a good perspective on the use of pins. The contact interaction between rotor and pins uses an elastic-dissipative model. In addition...

  6. How Helpful is Colour-Cueing of PIN Entry?

    OpenAIRE

    Renaud, Karen; Ramsay, Judith

    2014-01-01

    21st Century citizens are faced with the need to remember numbers of PINs (Personal Identification Numbers) in order to do their daily business, and they often have difficulties due to human memory limitations. One way of helping them could be by providing cues during the PIN entry process. The provision of cues that would only be helpful to the PIN owner is challenging because the cue should only make sense to the legitimate user, and not to a random observer. In this paper we report on an e...

  7. Discovery of novel selenium derivatives as Pin1 inhibitors by high-throughput screening

    International Nuclear Information System (INIS)

    Subedi, Amit; Shimizu, Takeshi; Ryo, Akihide; Sanada, Emiko; Watanabe, Nobumoto; Osada, Hiroyuki

    2016-01-01

    Peptidyl prolyl cis/trans isomerization by Pin1 regulates various oncogenic signals during cancer progression, and its inhibition through multiple approaches has established Pin1 as a therapeutic target. However, lack of simplified screening systems has limited the discovery of potent Pin1 inhibitors. We utilized phosphorylation-dependent binding of Pin1 to its specific substrate to develop a screening system for Pin1 inhibitors. Using this system, we screened a chemical library, and identified a novel selenium derivative as Pin1 inhibitor. Based on structure-activity guided chemical synthesis, we developed more potent Pin1 inhibitors that inhibited cancer cell proliferation. -- Highlights: •Novel screening for Pin1 inhibitors based on Pin1 binding is developed. •A novel selenium compound is discovered as Pin1 inhibitor. •Activity guided chemical synthesis of selenium derivatives resulted potent Pin1 inhibitors.

  8. Standard and Null Weak Values

    OpenAIRE

    Zilberberg, Oded; Romito, Alessandro; Gefen, Yuval

    2013-01-01

    Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.

  9. Weak openness and almost openness

    Directory of Open Access Journals (Sweden)

    David A. Rose

    1984-01-01

    Full Text Available Weak openness and almost openness for arbitrary functions between topological spaces are defined as duals to the weak continuity of Levine and the almost continuity of Husain respectively. Independence of these two openness conditions is noted and comparison is made between these and the almost openness of Singal and Singal. Some results dual to those known for weak continuity and almost continuity are obtained. Nearly almost openness is defined and used to obtain an improved link from weak continuity to almost continuity.

  10. Weak measurements and quantum weak values for NOON states

    Science.gov (United States)

    Rosales-Zárate, L.; Opanchuk, B.; Reid, M. D.

    2018-03-01

    Quantum weak values arise when the mean outcome of a weak measurement made on certain preselected and postselected quantum systems goes beyond the eigenvalue range for a quantum observable. Here, we propose how to determine quantum weak values for superpositions of states with a macroscopically or mesoscopically distinct mode number, that might be realized as two-mode Bose-Einstein condensate or photonic NOON states. Specifically, we give a model for a weak measurement of the Schwinger spin of a two-mode NOON state, for arbitrary N . The weak measurement arises from a nondestructive measurement of the two-mode occupation number difference, which for atomic NOON states might be realized via phase contrast imaging and the ac Stark effect using an optical meter prepared in a coherent state. The meter-system coupling results in an entangled cat-state. By subsequently evolving the system under the action of a nonlinear Josephson Hamiltonian, we show how postselection leads to quantum weak values, for arbitrary N . Since the weak measurement can be shown to be minimally invasive, the weak values provide a useful strategy for a Leggett-Garg test of N -scopic realism.

  11. A PWR Thorium Pin Cell Burnup Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Kevan Dean; Zhao, X.; Pilat, E. E; Hejzlar, P.

    2000-05-01

    As part of work to evaluate the potential benefits of using thorium in LWR fuel, a thorium fueled benchmark comparison was made in this study between state-of-the-art codes, MOCUP (MCNP4B + ORIGEN2), and CASMO-4 for burnup calculations. The MOCUP runs were done individually at MIT and INEEL, using the same model but with some differences in techniques and cross section libraries. Eigenvalue and isotope concentrations were compared on a PWR pin cell model up to high burnup. The eigenvalue comparison as a function of burnup is good: the maximum difference is within 2% and the average absolute difference less than 1%. The isotope concentration comparisons are better than a set of MOX fuel benchmarks and comparable to a set of uranium fuel benchmarks reported in the literature. The actinide and fission product data sources used in the MOCUP burnup calculations for a typical thorium fuel are documented. Reasons for code vs code differences are analyzed and discussed.

  12. Pinning Control Strategy of Multicommunity Structure Networks

    Directory of Open Access Journals (Sweden)

    Chao Ding

    2017-01-01

    Full Text Available In order to investigate the effects of community structure on synchronization, a pinning control strategy is researched in a class of complex networks with community structure in this paper. A feedback control law is designed based on the network community structure information. The stability condition is given and proved by using Lyapunov stability theory. Our research shows that as to community structure networks, there being a threshold hT≈5, when coupling strength bellows this threshold, the stronger coupling strength corresponds to higher synchronizability; vice versa, the stronger coupling strength brings lower synchronizability. In addition the synchronizability of overlapping and nonoverlapping community structure networks was simulated and analyzed; while the nodes were controlled randomly and intensively, the results show that intensive control strategy is better than the random one. The network will reach synchronization easily when the node with largest betweenness was controlled. Furthermore, four difference networks’ synchronizability, such as Barabási-Albert network, Watts-Strogatz network, Erdös-Rényi network, and community structure network, are simulated; the research shows that the community structure network is more easily synchronized under the same control strength.

  13. Ideal glass transitions by random pinning

    Science.gov (United States)

    Cammarota, Chiara; Biroli, Giulio

    2012-01-01

    We study the effect of freezing the positions of a fraction c of particles from an equilibrium configuration of a supercooled liquid at a temperature T. We show that within the random first-order transition theory pinning particles leads to an ideal glass transition for a critical fraction c = cK(T) even for moderate supercooling; e.g., close to the Mode-Coupling transition temperature. First we derive the phase diagram in the T - c plane by mean field approximations. Then, by applying a real-space renormalization group method, we obtain the critical properties for |c - cK(T)| → 0, in particular the divergence of length and time scales, which are dominated by two zero-temperature fixed points. We also show that for c = cK(T) the typical distance between frozen particles is related to the static point-to-set length scale of the unconstrained liquid. We discuss what are the main differences when particles are frozen in other geometries and not from an equilibrium configuration. Finally, we explain why the glass transition induced by freezing particles provides a new and very promising avenue of research to probe the glassy state and ascertain, or disprove, the validity of the theories of the glass transition. PMID:22623524

  14. Dynamic behaviour of FBR fuel pin bundles

    International Nuclear Information System (INIS)

    Martin, P.H.; Van Dorsselaere, J.P.; Ravenet, A.

    1990-01-01

    A programme of shock tests on a fast neutron reactor subassembly model (SPX1 geometry) including a complete bundle of fuel pins (dummy elements) is being carried out in the BELIER test facility at Cadarache. The purpose of these tests is: to determine the distribution of dynamic forces applied to the fuel rod clads under the impact conditions encountered in a reactor during a earthquake; to reduce as much as possible the conservatism of the methods presently used for the calculation of those forces. The test programme, now being completed, consists of the following steps: impacts on the mock-up in air with an non-compact bundle (situation of the subassembly at beginning of life (BOL) with clearances within the bundle); impacts under the same conditions but with fluid (water) in the subassembly; impacts on the mock-up in air and with a compacted bundle (simulating the conditions of an end-of-life (EOL) bundle with no clearance within the bundle). The accelerations studied in these tests cover the range encountered in design calculations for the subassembly frequencies in beam mode. (author)

  15. Transverse pinning versus intramedullary pinning in fifth metacarpal's neck fractures: A randomized controlled study with patient-reported outcome.

    Science.gov (United States)

    Galal, Sherif; Safwat, Wael

    2017-01-01

    The 5th metacarpal fractures accounts for 38% of all hand fractures given that the neck is the weakest point in metacarpals, so neck fracture is the most common metacarpal fracture. Surgical fixation is also advocated for such fractures to prevent mal-rotation of the little finger which will lead to fingers overlap in a clenched fist. Various methods are available for fixation of such fractures, like intramedullary & transverse pinning. There are very few reports in the literature comparing both techniques. Authors wanted to compare outcomes and complications of transverse pinning versus intramedullary pinning in fifth metacarpal's neck fractures. A single-center, parallel group, prospective, randomized study was conducted at an academic Level 1 Trauma Center from October 2014 to December 2016. A total of 80 patients with 5th metacarpal's neck fractures were randomized to pinning using either transverse pinning (group A) or intramedullary pinning (group B). Patients were assessed clinically on range of motion, patient-reported outcome using the Quick-DASH (Disabilities of the Arm, Shoulder, and Hand) questionnaire & radiographically. Two blinded observers assessed outcomes. At final follow up for each patient (12 months) the statistically significant differences were observed in operative time, the transverse pinning group showed shorter operative time, as well as complication rate as complications were observed only in intramedullary pinning group. No differences were found in range of motion or the Quick -DASH score. Both techniques are equally safe and effective treatment option for 5th metacarpal's neck fractures. The only difference was shorter operative time & less incidence of complications in transverse pinning group. Level II, Therapeutic study.

  16. Close Proximity Robotic Maneuvering through Flux Pinning Manipulation

    Data.gov (United States)

    National Aeronautics and Space Administration — Non-contacting actuation technology like flux pinning has never been demonstrated in space. The development of a nonphysical joint is critical for maneuvers such as...

  17. Pin failure modeling of the A series CABRI tests

    International Nuclear Information System (INIS)

    Young, M.F.; Portugal, J.L.

    1978-01-01

    The EXPAND pin fialure model, a research tool designed to model pin failure under prompt burst conditions, has been used to predict failure conditions for several of the A series CABRI tests as part of the United States participation in the CABRI Joint Project. The Project is an international program involving France, Germany, England, Japan, and the United States and has the goal of obtaining experimental data relating to the safety of LMFBR's. The A series, designed to simulate high ramp rate TOP conditions, initially utilizes single, fresh UO 2 pins of the PHENIX type in a flowing sodium loop. The pins are preheated at constant power in the CABRI reactor to establish steady state conditions (480 w/cm at the axial peak) and then subjected to a power pulse of 14 ms to 24 ms duration

  18. Progress in fuel pin modelling in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Stephen, J D; Biancheria, A; Leibnitz, D; O' Reilly, B D; Liu, Y Y; Labar, M P; Gneiting, B C [General Electric Company, Sunnyvale, CA (United States)

    1979-12-01

    In the USA, the focus for theoretical fuel pin modeling is the LIFE system. This system of codes, algorithms, criteria and analysis guidelines is intended to provide a common basis for communication amongst the development groups, a reference set of analysis guidelines for design, and eventually a consensus on the state-of-the-art for licensing. The technical objective is to predict the effect of design options on fuel pin performance limits, which include fuel temperature, pin deformation and cladding breach during normal operation and design basis transients. The mechanistic approach to modeling is taken in LIFE to the extent possible. That is, the approach is to describe the key phenomena in sufficient detail to provide a fundamental understanding of their synergistic effect on the fuel pin performance limits.

  19. The treatment of burnable poison pins in LWRWIMS

    International Nuclear Information System (INIS)

    Halsall, M.J.

    1982-12-01

    This report describes an investigation into the modelling approximations normally made when the LWR lattice code LWRWIMS is used for design calculations on assemblies containing burnable poison pins. Parameters investigated include energy group structure, intervals between calculations in MWd/te and spatial subdivision of the poison pins. An estimate is made of the effect of using pin-cell smearing with diffusion theory for the assembly geometry, instead of a more exact heterogeneous transport theory calculation. The influence on reactivity of the minor gadolinium isotopes 152, 154, 156, 158 and 160 in a poison pin dominated by the isotopes 155 and 157 is presented, and finally, recommendations on the use of LWRWIMS for this type of calculation are made. (author)

  20. PIN architecture for ultrasensitive organic thin film photoconductors.

    Science.gov (United States)

    Jin, Zhiwen; Wang, Jizheng

    2014-06-17

    Organic thin film photoconductors (OTFPs) are expected to have wide applications in the field of optical communications, artificial vision and biomedical sensing due to their great advantages of high flexibility and low-cost large-area fabrication. However, their performances are not satisfactory at present: the value of responsivity (R), the parameter that measures the sensitivity of a photoconductor to light, is below 1 AW(-1). We believe such poor performance is resulted from an intrinsic self-limited effect of present bare blend based device structure. Here we designed a PIN architecture for OTFPs, the PIN device exhibits a significantly improved high R value of 96.5 AW(-1). The PIN architecture and the performance the PIN device shows here should represent an important step in the development of OTFPs.

  1. SP-100 Fuel Pin Performance: Results from Irradiation Testing

    Science.gov (United States)

    Makenas, Bruce J.; Paxton, Dean M.; Vaidyanathan, Swaminathan; Marietta, Martin; Hoth, Carl W.

    1994-07-01

    A total of 86 experimental fuel pins with various fuel, liner, and cladding candidate materials have been irradiated in the Experimental Breeder Reactor-II (EBR-II) and the Fast Flux Test Facility (FFTF) reactor as part of the SP-100 fuel pin irradiation testing program. Postirradiation examination results from these fuel pins are key in establishing performance correlations and demonstrating the lifetime and safety of the reactor fuel system. This paper provides a brief description of the in-reactor fuel pin tests and presents the most recent irradiation data on the performance of wrought rhenium (Re) liner material and high density UN fuel at goal burnup of 6 atom percent (at. %). It also provides an overview of the significant variety of other fuel/liner/cladding combinations which were irradiated as part of this program and which may be of interest to more advanced efforts.

  2. Weak decays of stable particles

    International Nuclear Information System (INIS)

    Brown, R.M.

    1988-09-01

    In this article we review recent advances in the field of weak decays and consider their implications for quantum chromodynamics (the theory of strong interactions) and electroweak theory (the combined theory of electromagnetic and weak interactions), which together form the ''Standard Model'' of elementary particles. (author)

  3. Behavior of a bundle of fast fuel pins under irradiation

    International Nuclear Information System (INIS)

    Marbach, G.; Millet, P.; Robert, J.; Languille, A.

    1979-01-01

    In the French design of fuel elements for fast reactors, great deformation of pins can bring about interaction with the hexagonal tube through the spacer wires. The change in such bundles is described here when the diameter of the cladding increases and the outcome of this reaction (bending and ovalization of pins) is calculated with a simplified model. It is shown that the results achieved agree well with the experimental observations [fr

  4. Pin and roller attachment system for ceramic blades

    Science.gov (United States)

    Shaffer, J.E.

    1995-07-25

    In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

  5. Cyclic movement pin mechanism for controlling a nuclear reactor

    International Nuclear Information System (INIS)

    Joly, J.G.; Martin, Jean.

    1981-01-01

    This invention concerns a recurring movement pin mechanism for controlling a nuclear reactor by shifting a neutron absorbing assembly, vertically mobile in the nuclear reactor, to adjust the power and for emergency shut-down. This mechanism ensures a continuous movement and accurate shut-down at any level of the travel height of the absorbing assembly in the core. It also prevents the impacts of the pivoting pins in the control rod slots [fr

  6. Electromagnetic current in weak interactions

    International Nuclear Information System (INIS)

    Ma, E.

    1983-01-01

    In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current

  7. Weak values in collision theory

    Science.gov (United States)

    de Castro, Leonardo Andreta; Brasil, Carlos Alexandre; Napolitano, Reginaldo de Jesus

    2018-05-01

    Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising results after post-selection. That description often ignores the kinetic energy of the particle and its movement in three dimensions. Here, we include these elements and re-obtain the weak values within the context of collision theory by two different approaches, and prove that the results are compatible with each other and with the results from the traditional approach. To provide a more complete description, we generalize weak values into weak tensors and use them to provide a more realistic description of the Stern-Gerlach apparatus.

  8. Comparison of proton microbeam and gamma irradiation for the radiation hardness testing of silicon PIN diodes

    Science.gov (United States)

    Jakšić, M.; Grilj, V.; Skukan, N.; Majer, M.; Jung, H. K.; Kim, J. Y.; Lee, N. H.

    2013-09-01

    Simple and cost-effective solutions using Si PIN diodes as detectors are presently utilized in various radiation-related applications in which excessive exposure to radiation degrades their charge transport properties. One of the conventional methods for the radiation hardness testing of such devices is time-consuming irradiation with electron beam or gamma-ray irradiation facilities, high-energy proton accelerators, or with neutrons from research reactors. Recently, for the purpose of radiation hardness testing, a much faster nuclear microprobe based approach utilizing proton irradiation has been developed. To compare the two different irradiation techniques, silicon PIN diodes have been irradiated with a Co-60 gamma radiation source and with a 6 MeV proton microbeam. The signal degradation in the silicon PIN diodes for both irradiation conditions has been probed by the IBIC (ion beam induced charge) technique, which can precisely monitor changes in charge collection efficiency. The results presented are reviewed on the basis of displacement damage calculations and NIEL (non-ionizing energy loss) concept.

  9. Incidence and risk factors for pin tract infection in external fixation of ...

    African Journals Online (AJOL)

    Incidence and risk factors for pin tract infection in external fixation of fractures ... for pin tract infection, there were 93 pins scored grade 1, 32 pins grade 2, 15 ... The incidence increased from 20.5% in closed fractures to 75.9% in open fractures.

  10. JMCT Monte Carlo simulation analysis of full core PWR Pin-By-Pin and shielding

    International Nuclear Information System (INIS)

    Deng, L.; Li, G.; Zhang, B.; Shangguan, D.; Ma, Y.; Hu, Z.; Fu, Y.; Li, R.; Hu, X.; Cheng, T.; Shi, D.

    2015-01-01

    This paper describes the application of the JMCT Monte Carlo code to the simulation of Kord Smith Challenge H-M model, BEAVRS model and Chinese SG-III model. For H-M model, the 6.3624 millions tally regions and the 98.3 billion neutron histories do. The detailed pin flux and energy deposition densities obtain. 95% regions have less 1% standard deviation. For BEAVRS model, firstly, we performed the neutron transport calculation of 398 axial planes in the Hot Zero Power (HZP) status. Almost the same results with MC21 and OpenMC results are achieved. The detailed pin-power density distribution and standard deviation are shown. Then, we performed the calculation of ten depletion steps in 30 axial plane cases. The depletion regions exceed 1.5 million and 12,000 processors uses. Finally, the Chinese SG-III laser model is simulated. The neutron and photon flux distributions are given, respectively. The results show that the JMCT code well suits for extremely large reactor and shielding simulation. (author)

  11. A polygonal nodal SP3 method for whole core Pin-by-Pin neutronics calculation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yunzhao; Wu, Hongchun; Cao, Liangzhi, E-mail: xjtulyz@gmail.com, E-mail: hongchun@mail.xjtu.edu.cn, E-mail: caolz@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi' an Jiaotong University, Shaanxi (China)

    2011-07-01

    In this polygonal nodal-SP3 method, neutron transport equation is transformed by employing an isotropic SP3 method into two coupled equations that are both in the same mathematic form with the diffusion equation, and then a polygonal nodal method is proposed to solve the two coupled equations. In the polygonal nodal method, adjacent nodes are coupled through partial currents, and a nodal response matrix between incoming and outgoing currents is obtained by expanding detailed nodal flux distribution into a sum of exponential functions. This method avoids the transverse integral technique, which is widely used in regular nodal method and can not be used in triangular geometry because of the mathematical singularity. It is demonstrated by the numerical results of the test problems that the k{sub eff} and power distribution agree well with other codes, the triangular nodal-SP3 method appears faster, and that whole core pin-by-pin transport calculation with fine meshes is feasible after parallelization and acceleration. (author)

  12. Development of modeling tools for pin-by-pin precise reactor simulation

    International Nuclear Information System (INIS)

    Ma Yan; Li Shu; Li Gang; Zhang Baoyin; Deng Li; Fu Yuanguang

    2013-01-01

    In order to develop large-scale transport simulation and calculation method (such as simulation of whole reactor core pin-by-pin problem), the Institute of Applied Physics and Computational Mathematics developed the neutron-photon coupled transport code JMCT and the toolkit JCOGIN. Creating physical calculation model easily and efficiently can essentially reduce problem solving time. Currently, lots of visual modeling programs have been developed based on different CAD systems. In this article, the developing idea of a visual modeling tool based on field oriented development was introduced. Considering the feature of physical modeling, fast and convenient operation modules were developed. In order to solve the storage and conversion problems of large scale models, the data structure and conversional algorithm based on the hierarchical geometry tree were designed. The automatic conversion and generation of physical model input file for JMCT were realized. By using this modeling tool, the Dayawan reactor whole core physical model was created, and the transformed file was delivered to JMCT for transport calculation. The results validate the correctness of the visual modeling tool. (authors)

  13. Pinning and irreversibility in superconducting bulk MgB{sub 2} with added nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Anurag [Superconductivity and Cryogenics Division, National Physical Laboratory (CSIR), New Delhi-110012 (India); Narlikar, A V, E-mail: anurag@mail.nplindia.ernet.i [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452017, MP (India)

    2009-12-15

    Resistance, R(T), and magnetization, M(B), studies on superconducting bulk MgB{sub 2} samples containing nanodiamonds (ND) as additives (wt% of ND: x = 0%, 1%, 3%, 5%, 7% and 10%) were recently published in two articles (Vajpayee et al 2007 Supercond. Sci. Technol. 20 S155, Vajpayee et al 2008 J. Appl. Phys. 103 07C708). The main observations reported were significant improvements in the critical current density J{sub c}(B), irreversibility line B{sub irr}(T) and upper critical field B{sub c2}(T) with ND addition. However, a closer look shows that as regards the potential of this technologically important material at higher magnetic fields and temperatures, there is still a lot of room for improvement. With that in mind we revisit the R(T) and M(B) data and analyze them, in the present work. We show that, despite ND addition, J{sub c} depends strongly on B in the high field region and tends to vanish at irreversibility lines that lie deep, i.e. at around 0.3 B{sub c2}(T), in the B-T phase diagram. The irreversibility lines, determined by R(T){yields}0 in the presence of B, are found to lie at around 0.5 B{sub c2}(T) in the phase diagram. These results for pinning and irreversibility lines are discussed in the light of various models such as those of surface sheath superconductivity, magnetically introduced percolation in polycrystalline MgB{sub 2}, thermally assisted flux motion (TAFM) and a modified flux line shear mechanism. Our analysis hints at TAFM and weak pinning channels with distributed superconducting properties percolating in our samples determining the irreversibility and pinning properties.

  14. Repeat biopsy in patients with initial diagnosis of PIN; La biopsia ripetuta nei pazienti con diagnosi iniziale di PIN

    Energy Technology Data Exchange (ETDEWEB)

    De Matteis, Massimo [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia Albertoni; Poggi, Cristina; De Martino, Antonietta; Pavlica, Pietro [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia Palagi, Dipartimento area radiologica; Corti, Barbara [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Anatomia ed istologia patologica, Dipartimento oncologico ed ematologico; Barozzi, Libero [Azienda Ospedaliera Policlinico S. Orsola-Malpighi, Bologna (Italy). UO Radiologia d' urgenza, Dipartimento emergenze ed accettazione

    2005-09-15

    Purpose. Prostatic intra-epithelial neoplasia (PIN) is considered a pre-malignant lesion and the main precursor of invasive prostatic adenocarcinoma. A PIN diagnosis established by prostate needle biopsy poses a difficult clinical management. problem. We retrospectively reviewed our three-year experience in order to identify criteria for referring patients to repeat biopsy. Materials and methods. We reviewed the repeat biopsy records of 72 patients in whom PIN had been detected on initial US-guided needle biopsy of the prostate. All the patients had a minimum of 6 biopsy cores taken, and they all had PSA > 4 ng/ml. Results. Adenocarcinoma was detected in 15 patients out of 50 (30%) with an initial diagnosis of low-grade PIN and in 10 patients out of 22 (45.4%) with high grade PIN, in 7 out of 18 (39%) in whom PSA levels had decreased during the observation interval, in 16 patients out of 46 (35%) in whom the PSA had increased and in 2 patients out of 8 (25%) with stable PSA. Conclusions. Our results seem to confirm that PIN can be considered a precursor of prostatic adenocarcinoma or a histological alteration often associated with it. Patients with low-grade PIN and particularly those with high-grade PIN should be regularly subjected to repeat biopsy at short intervals due to the high frequency of the final diagnosis of carcinoma. No agreement has been reached on the time interval between the first and the second biopsy. The PSA changes during the observation period are not a statistically significant parameter to suggest the repetition of prostatic biopsy. [Italian] Scopo. La neoplasia prostatica intraepiteliale (PIN) e considerata una lesione premaligna ed il precursore principale dell'adenocarcinoma prostatico infiltrante. La diagnosi di PIN ottenuta con l'agobiopsia della prostata rappresenta un difficile problema gestionale clinico. In una valutazione retrospettiva della nostra esperienza di 3 anni si e cercato di individuare i criteri che possano

  15. Fuel pin bowing and related investigation of WWER-440 control rod influence on power release inside of neighbouring fuel pins

    International Nuclear Information System (INIS)

    Mikus, J.

    2005-01-01

    The purpose of this work consists in investigation of the WWER-440 control rod (CR) influence on space power distribution, especially from viewpoint of the values and gradient occurrence that could result in static and cyclic loads with some consequences, e.g. fuel pin bowing. As known, CR can cause power peaks in periphery fuel pins of adjacent operating assemblies because of the butt joint design of the absorbing adapter to the CR fuel part, that is, presence of the water cavity resulting in a flash up of thermal neutrons. As a consequence, beside well-known peaks in axial power distribution, above power gradients can occur inside of mentioned fuel pins. Because of complicated geometry and material composition of the CR, the detailed calculations concerning both above phenomena are complicated, too. Therefore it is useful to acquire appropriate experimental data to investigate mentioned influence and compare them with calculations. Since detailed power distributions cannot be obtained in the NPP, needed information is provided by means of experiments on research reactors. In case of measurements inside of fuel pins, special (e.g. track) detectors placed between fuel pellets are used. Such works are relatively complicated and time consuming, therefore an evaluation based on mathematical modelling and numerical approximation was proposed by means of that, and using measured power release in some selected fuel pins, information about power release inside of one of these fuel pins, can be obtained. For this purpose, an experiment on light water, zero-power research reactor LR-0 was realized and axial power distribution measurements were performed in a WWER-440 type core near to an authentic CR model. Application of the above evaluation method is demonstrated on one ''investigated'' fuel pin neighbouring CR by means of following results: 1. Axial power distribution inside of investigated fuel pin in two opposite positions on its pellets surface that are situated to

  16. Hartman effect and weak measurements that are not really weak

    International Nuclear Information System (INIS)

    Sokolovski, D.; Akhmatskaya, E.

    2011-01-01

    We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width σ small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio σ/d.

  17. Complications after pinning of supracondylar distal humerus fractures.

    Science.gov (United States)

    Bashyal, Ravi K; Chu, Jennifer Y; Schoenecker, Perry L; Dobbs, Matthew B; Luhmann, Scott J; Gordon, J Eric

    2009-01-01

    Supracondylar distal humerus fractures are one of the most common skeletal injuries in children. The current treatment of choice in North America is closed reduction and percutaneous pin fixation. Often surgeons leave the pins exposed beneath a cast but outside the skin. Great variation exists with respect to preoperative skin preparation, and perioperative antibiotic administration. Few data exist regarding the rate of infection and other complications. The purpose of this study is to review a large series of children to evaluate the rate of infection and other complications. A retrospective review was carried out of all patients treated at our institution over an 11-year period. A total of 622 patients were identified that were followed for a minimum of 2 weeks after pin removal. Seventeen patients had flexion-type fractures, 294 had type II fractures, and 311 had type III fractures. Seventy-four fractures (11.9%) had preoperative nerve deficits with anterior interosseous palsies being the most common (33 fractures, 5.3%). Preoperative antibiotics were given to 163 patients (26.2%). Spray and towel draping were used in 362 patients, paint and towel draping were used in 65 patients, alcohol paint and towel draping were used in 146 patients, and a full preparation and draping were used in 13 patients. The pins were left exposed under the cast in 591 fractures (95%), and buried beneath the skin in 31 fractures (5.0%). A medial pin was placed in 311 fractures with a small incision made to aid placement in 18 of these cases. The most common complication was pin migration necessitating unexpected return to the operating room for pin removal in 11 patients (1.8%). One patient developed a deep infection with septic arthritis and osteomyelitis (0.2%). Five additional patients had superficial skin infections and were treated with oral antibiotics for a total infection rate of 6 of 622 patients (1.0%). One patient ultimately had a malunion and 4 others returned to the

  18. High-performance whole core Pin-by-Pin calculation based on EFEN-SP_3 method

    International Nuclear Information System (INIS)

    Yang Wen; Zheng Youqi; Wu Hongchun; Cao Liangzhi; Li Yunzhao

    2014-01-01

    The EFEN code for high-performance PWR whole core pin-by-pin calculation based on the EFEN-SP_3 method can be achieved by employing spatial parallelization based on MPI. To take advantage of the advanced computing and storage power, the entire problem spatial domain can be appropriately decomposed into sub-domains and the assigned to parallel CPUs to balance the computing load and minimize communication cost. Meanwhile, Red-Black Gauss-Seidel nodal sweeping scheme is employed to avoid the within-group iteration deterioration due to spatial parallelization. Numerical results based on whole core pin-by-pin problems designed according to commercial PWRs demonstrate the following conclusions: The EFEN code can provide results with acceptable accuracy; Communication period impacts neither the accuracy nor the parallel efficiency; Domain decomposition methods with smaller surface to volume ratio leads to greater parallel efficiency; A PWR whole core pin-by-pin calculation with a spatial mesh 289 × 289 × 218 and 4 energy groups could be completed about 900 s by using 125 CPUs, and its parallel efficiency is maintained at about 90%. (authors)

  19. Coordination of networked systems on digraphs with multiple leaders via pinning control

    Science.gov (United States)

    Chen, Gang; Lewis, Frank L.

    2012-02-01

    It is well known that achieving consensus among a group of multi-vehicle systems by local distributed control is feasible if and only if all nodes in the communication digraph are reachable from a single (root) node. In this article, we take into account a more general case that the communication digraph of the networked multi-vehicle systems is weakly connected and has two or more zero-in-degree and strongly connected subgraphs, i.e. there are two or more leader groups. Based on the pinning control strategy, the feasibility problem of achieving second-order controlled consensus is studied. At first, a necessary and sufficient condition is given when the topology is fixed. Then the method to design the controller and the rule to choose the pinned vehicles are discussed. The proposed approach allows us to extend several existing results for undirected graphs to directed balanced graphs. A sufficient condition is proposed in the case where the coupling topology is variable. As an illustrative example, a second-order controlled consensus scheme is applied to coordinate the movement of networked multiple mobile robots.

  20. Resistive transition of superconducting-wire networks. Influence of pinning and fluctuations

    International Nuclear Information System (INIS)

    Giroud, M.; Buisson, O.; Wang, Y.Y.; Pannetier, B.; Mailly, D.

    1992-01-01

    The authors studied the resistive transition of several 2-D superconducting-wire networks of various coupling strengths, which they characterize in terms of the Kosterlitz-Thouless transition temperature and the ratio ξ/a of the coherence length to the array period. In the extreme strong-coupling limit where the mesh size is of the order of the zero-temperature coherence length, the superconducting behavior is well described by the mean-field properties of the superconducting wave function. Extending to 2-D array, the 1-D phase-slippage model explains the dissipative regime observed above the Ginzburg-Landau depairing critical current. On the other hand, when the coupling is weak, phase fluctuations below the Ginzburg-Landau transition and vortex depinning dominate the resistive behavior. An activated dissipation is observed even below the depairing critical current. Results obtained in this regime for critical temperature, magnetoresistance, or critical current versus temperature, and magnetic field are shown; their periodic oscillations are discussed in terms of depinning of vortices on the array. A simple periodic pinning potential for a vortex in a wire network is calculated, and compared with the case of pinning in Josephson junction arrays. It is shown that this model explains qualitatively the experimental results observed for small ξ/a

  1. Multilevel parallel strategy on Monte Carlo particle transport for the large-scale full-core pin-by-pin simulations

    International Nuclear Information System (INIS)

    Zhang, B.; Li, G.; Wang, W.; Shangguan, D.; Deng, L.

    2015-01-01

    This paper introduces the Strategy of multilevel hybrid parallelism of JCOGIN Infrastructure on Monte Carlo Particle Transport for the large-scale full-core pin-by-pin simulations. The particle parallelism, domain decomposition parallelism and MPI/OpenMP parallelism are designed and implemented. By the testing, JMCT presents the parallel scalability of JCOGIN, which reaches the parallel efficiency 80% on 120,000 cores for the pin-by-pin computation of the BEAVRS benchmark. (author)

  2. Development of a semiconductor neutron dosimeter with a PIN diode

    International Nuclear Information System (INIS)

    Kim, Seungho; Lee, Namho; Cho, Jaiwan; Youk, Geunuck

    2004-01-01

    When a Si PIN diode is exposed to fast neutrons, it produces displacement in Si lattice structure of the diode. Defects induced from structural dislocation become effective recombination centers for carriers which pass through the base of a PIN diode. Hence, increasing the resistivity of the diode decreases the current for the applied forward voltage. This paper involves the development of a neutron sensor based on the phenomena of the displacement effect damaged by neutron exposure. The neutron effect on the semiconductor was analyzed, and multi PIN diode arrays with various intrinsic layer (I layer) thicknesses and cross sections were fabricated. Under irradiation tests with a neutron beam, the manufactured diodes have good characteristics of linearity in a neutron irradiation experiment and give results that the increase of thickness of I layer and the decrease of the cross-section of the PIN diodes improve the sensitivity. Newly developed PIN diodes with a thicker I layer and various cross sections were retested and showed the best neutron sensitivity in the condition that the I layer thickness was similar to the length of a side of the cross-section. On the basis of two test results, final PIN diodes with a rectangular shape were manufactured and the characteristics for neutron detectors were analyzed through the neutron beam test using the on-line electronic dosimetry system. The developed PIN diode shows a good linearity to absorbed dose in the range of 0 to 1,000cGy (Tissue) and its neutron sensitivity is 13 mV/cGy at a constant current of 5 mA, that is three higher than that of similar commercially developed neutron detectors. Moreover the device shows less dependency on the orientation of the neutron beam and a considerable stability in an annealing test for a long period. (author)

  3. Fuel pin response to an overpower transient in an LMFBR

    International Nuclear Information System (INIS)

    Grosberg, A.J.; Head, J.L.

    1979-01-01

    This paper describes a method by which the ability of a whole-core code accurately to predict the time and location of the first fuel pin failures may be tested. The method involves the use of a relatively simple whole-core code to 'drive' a sophisticated fuel pin code, which is far too complex to be used within a whole-core code but which is potentially capable of modelling reliably the response of an individual fuel pin. The method cannot follow accurately the subsequent course of the transient because the simple whole-core code does not model the reactivity effects of events which may follow pin failure. The codes used were the simple whole-core code FUTURE and the fuel pin behaviour code FRUMP. The paper describes an application of the method to analyse a hypothetical LMFBR accident in which the control rods were assumed to be driven from the core at maximum speed, with all trip circuits failed. Taking 0.5% clad strain as a clad failure criterion, failure was predicted to occur at the top of the active core at about 10s into the transient. A repeat analysis, using an alternative clad yield criterion which is thought to be more realistic, indicated failure at the same position but 24s into the transient. This is after the onset of sodium boiling. Pin failure at the top of the core are likely to cause negative reactivity changes. In this hypothetical accident, pin failures are likely, therefore, to have a moderating effect on the course of the transient. (orig.)

  4. Weak Measurement and Quantum Correlation

    Indian Academy of Sciences (India)

    Arun Kumar Pati

    Entanglement: Two quantum systems can be in a strongly correlated state even if .... These are resources which can be used to design quantum computer, quantum ...... Weak measurements have found numerous applications starting from the ...

  5. Weakly infinite-dimensional spaces

    International Nuclear Information System (INIS)

    Fedorchuk, Vitalii V

    2007-01-01

    In this survey article two new classes of spaces are considered: m-C-spaces and w-m-C-spaces, m=2,3,...,∞. They are intermediate between the class of weakly infinite-dimensional spaces in the Alexandroff sense and the class of C-spaces. The classes of 2-C-spaces and w-2-C-spaces coincide with the class of weakly infinite-dimensional spaces, while the compact ∞-C-spaces are exactly the C-compact spaces of Haver. The main results of the theory of weakly infinite-dimensional spaces, including classification via transfinite Lebesgue dimensions and Luzin-Sierpinsky indices, extend to these new classes of spaces. Weak m-C-spaces are characterised by means of essential maps to Henderson's m-compacta. The existence of hereditarily m-strongly infinite-dimensional spaces is proved.

  6. Weak interactions and presupernova evolution

    International Nuclear Information System (INIS)

    Aufderheide, M.B.; State Univ. of New York

    1991-01-01

    The role of weak interactions, particularly electron capture and β - decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs

  7. Weak Deeply Virtual Compton Scattering

    International Nuclear Information System (INIS)

    Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin

    2006-01-01

    We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities

  8. Acute muscular weakness in children

    Directory of Open Access Journals (Sweden)

    Ricardo Pablo Javier Erazo Torricelli

    Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.

  9. Autophagy regulated by prolyl isomerase Pin1 and phospho-Ser-GSK3αβ involved in protection of oral squamous cell carcinoma against cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    So, Keum-Young [Department of Anesthesiology and Pain Medicine College of Dentistry, Chosun University, 309 Pilmundaero, Dong-gu, Gwangju 501-759 (Korea, Republic of); Ahn, Sang-Gun [Department of Pathology, College of Dentistry, Chosun University, 309 Pilmundaero, Dong-gu, Gwangju 501-759 (Korea, Republic of); Oh, Seon-Hee, E-mail: seonh@chosun.ac.kr [Department of Premedicine, School of Medicine, College of Dentistry, Chosun University, 309 Pilmundaero, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2015-10-23

    Prolyl isomerase Pin1 plays an important role in cell proliferation and is overexpressed in many human tumors. However, its role in autophagy induction remains undefined. Here we show that Pin1 regulates cell survival via autophagy in cadmium (Cd)-exposed oral squamous cell carcinoma (OSCC). OSCC exposure to Cd induced autophagy, as demonstrated by the formation of green fluorescent punctae in transfected cells expressing GFP-conjugated microtubule-associated protein light chain 3 (LC3) and by LC3 flux in the presence of autophagy inhibitors. Suppression of Atg5 enhanced Cd-induced apoptosis, indicating that autophagy is involved in cell protection. In dose–response experiments, cleavage of procaspase-3, PARP-1, and LC3-II was induced by Cd with an IC{sub 50} of 45 μM. Expression of Pin1 was decreased at or above the Cd IC{sub 50} value and was inversely correlated with the level of phospho(p)-Ser-GSK3αβ. Genetic or pharmacologic inhibition of Pin1 suppressed Cd-induced autophagy, but increased p-Akt-mediated p-Ser-GSK3αβ; this was reversed by overexpression of Pin1. However, suppression of GSK3αβ inhibited Cd-induced autophagy and induced apoptosis, which could be reversed by overexpression of GSK3β. The PI3K inhibitor Ly294002 blocked p-Akt-mediated increases in p-Ser-GSK3αβ and autophagy and induced apoptosis. Therefore, p-Ser-GSK3αβ can directly regulate Cd-induced autophagy, although its function is suppressed by Pin1. Collectively, the present results indicate that targeting Pin1 and GSK3αβ at the same time could be an effective therapeutic tool for Cd-induced carcinogenesis. - Highlights: • Pin1 regulated autophagy to protect cells from cadmium toxicity. • Pin1 suppression inhibited cadmium-induced autophagy and induced apoptosis. • Pin1 inhibited the function of p-Ser-GSK3αβ in autophagy regulation. • p-Ser-GSK3αβ regulated autophagy independently of Pin1.

  10. Autophagy regulated by prolyl isomerase Pin1 and phospho-Ser-GSK3αβ involved in protection of oral squamous cell carcinoma against cadmium toxicity

    International Nuclear Information System (INIS)

    So, Keum-Young; Ahn, Sang-Gun; Oh, Seon-Hee

    2015-01-01

    Prolyl isomerase Pin1 plays an important role in cell proliferation and is overexpressed in many human tumors. However, its role in autophagy induction remains undefined. Here we show that Pin1 regulates cell survival via autophagy in cadmium (Cd)-exposed oral squamous cell carcinoma (OSCC). OSCC exposure to Cd induced autophagy, as demonstrated by the formation of green fluorescent punctae in transfected cells expressing GFP-conjugated microtubule-associated protein light chain 3 (LC3) and by LC3 flux in the presence of autophagy inhibitors. Suppression of Atg5 enhanced Cd-induced apoptosis, indicating that autophagy is involved in cell protection. In dose–response experiments, cleavage of procaspase-3, PARP-1, and LC3-II was induced by Cd with an IC_5_0 of 45 μM. Expression of Pin1 was decreased at or above the Cd IC_5_0 value and was inversely correlated with the level of phospho(p)-Ser-GSK3αβ. Genetic or pharmacologic inhibition of Pin1 suppressed Cd-induced autophagy, but increased p-Akt-mediated p-Ser-GSK3αβ; this was reversed by overexpression of Pin1. However, suppression of GSK3αβ inhibited Cd-induced autophagy and induced apoptosis, which could be reversed by overexpression of GSK3β. The PI3K inhibitor Ly294002 blocked p-Akt-mediated increases in p-Ser-GSK3αβ and autophagy and induced apoptosis. Therefore, p-Ser-GSK3αβ can directly regulate Cd-induced autophagy, although its function is suppressed by Pin1. Collectively, the present results indicate that targeting Pin1 and GSK3αβ at the same time could be an effective therapeutic tool for Cd-induced carcinogenesis. - Highlights: • Pin1 regulated autophagy to protect cells from cadmium toxicity. • Pin1 suppression inhibited cadmium-induced autophagy and induced apoptosis. • Pin1 inhibited the function of p-Ser-GSK3αβ in autophagy regulation. • p-Ser-GSK3αβ regulated autophagy independently of Pin1.

  11. Alpha particles spectrometer with photodiode PIN; Espectrometro de particulas alfa con fotodiodo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Calle Cipres No. 10, Fracc. La Penuela, 09869 Zacatecas (Mexico); Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico)], e-mail: achruiz@hotmail.com

    2009-10-15

    The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

  12. Defects influence on short circuit current density in p-i-n silicon solar cell

    International Nuclear Information System (INIS)

    Wagah F Mohamad; Alhan M Mustafa

    2006-01-01

    The admittance analysis method has been used to calculate the collection efficiency and the short circuit current density in a-Si:H p-i-n solar cell, as a function of the thickness of i-layer. Its is evident that the results of the short circuit current can be used to determine the optimal thickness of the i-layer of a cell, and it will be more accurate in comparison with the previous studies using a constant generation rate or an empirical exponential function for the generation of charge carriers throughout the i-layer

  13. Generation of clusters in complex dynamical networks via pinning control

    International Nuclear Information System (INIS)

    Li Kezan; Fu Xinchu; Small, Michael

    2008-01-01

    Many real-world networks show community structure, i.e., groups (or clusters) of nodes that have a high density of links within them but with a lower density of links between them. In this paper, by applying feedback injections to a fraction of network nodes, various clusters are synchronized independently according to the community structure generated by the group partition of the network (cluster synchronization). This control is achieved by pinning (i.e. applying linear feedback control) to a subset of the network nodes. Those pinned nodes are selected not randomly but according to the topological structure of communities of a given network. Specifically, for a given group partition of a network, those nodes with direct connections between groups must be pinned in order to achieve cluster synchronization. Both the local stability and global stability of cluster synchronization are investigated. Taking the tree-shaped network and the most modular network as two particular examples, we illustrate in detail how the pinning strategy influences the generation of clusters. The simulations verify the efficiency of the pinning schemes used in this paper

  14. A Flux-Pinning Mechanism for Segment Assembly and Alignment

    Science.gov (United States)

    Gersh-Range, Jessica A.; Arnold, William R.; Peck, Mason A.; Stahl, H. Philip

    2011-01-01

    Currently, the most compelling astrophysics questions include how planets and the first stars formed and whether there are protostellar disks that contain large organic molecules. Although answering these questions requires space telescopes with apertures of at least 10 meters, such large primaries are challenging to construct by scaling up previous designs; the limited capacity of a launch vehicle bounds the maximum diameter of a monolithic primary, and beyond a certain size, deployable telescopes cannot fit in current launch vehicle fairings. One potential solution is connecting the primary mirror segments edgewise using flux-pinning mechanisms, which are analogous to non-contacting damped springs. In the baseline design, a flux-pinning mechanism consists of a magnet and a superconductor separated by a predetermined gap, with the damping adjusted by placing aluminum near the interface. Since flux pinning is possible only when the superconductor is cooled below a critical temperature, flux-pinning mechanisms are uniquely suited for cryogenic space telescopes. By placing these mechanisms along the edges of the mirror segments, a primary can be built up over time. Since flux pinning requires no mechanical deployments, the assembly process could be robotic or use some other non-contacting scheme. Advantages of this approach include scalability and passive stability.

  15. Pin1 and neurodegeneration: a new player for prion disorders?

    Directory of Open Access Journals (Sweden)

    Elisa Isopi

    2015-07-01

    Full Text Available Pin1 is a peptidyl-prolyl isomerase that catalyzes the cis/trans conversion of phosphorylated proteins at serine or threonine residues which precede a proline. The peptidyl-prolyl isomerization induces a conformational change of the proteins involved in cell signaling process. Pin1 dysregulation has been associated with some neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Proline-directed phosphorylation is a common regulator of these pathologies and a recent work showed that it is also involved in prion disorders. In fact, prion protein phosphorylation at the Ser-43-Pro motif induces prion protein conversion into a disease-associated form. Furthermore, phosphorylation at Ser-43-Pro has been observed to increase in the cerebral spinal fluid of sporadic Creutzfeldt-Jakob Disease patients. These findings provide new insights into the pathogenesis of prion disorders, suggesting Pin1 as a potential new player in the disease. In this paper, we review the mechanisms underlying Pin1 involvement in the aforementioned neurodegenerative pathologies focusing on the potential role of Pin1 in prion disorders.

  16. Exchange anisotropy pinning of a standing spin-wave mode

    Science.gov (United States)

    Magaraggia, R.; Kennewell, K.; Kostylev, M.; Stamps, R. L.; Ali, M.; Greig, D.; Hickey, B. J.; Marrows, C. H.

    2011-02-01

    Standing spin waves in a thin film are used as sensitive probes of interface pinning induced by an antiferromagnet through exchange anisotropy. Using coplanar waveguide ferromagnetic resonance, pinning of the lowest energy spin-wave thickness mode in Ni80Fe20/Ir25Mn75 exchange-biased bilayers was studied for a range of Ir25Mn75 thicknesses. We show that pinning of the standing mode can be used to amplify, relative to the fundamental resonance, frequency shifts associated with exchange bias. The shifts provide a unique “fingerprint” of the exchange bias and can be interpreted in terms of an effective ferromagnetic film thickness and ferromagnet-antiferromagnet interface anisotropy. Thermal effects are studied for ultrathin antiferromagnetic Ir25Mn75 thicknesses, and the onset of bias is correlated with changes in the pinning fields. The pinning strength magnitude is found to grow with cooling of the sample, while the effective ferromagnetic film thickness simultaneously decreases. These results suggest that exchange bias involves some deformation of magnetic order in the interface region.

  17. Automation of FBTR fuel pin inspection using FPGA

    International Nuclear Information System (INIS)

    Khare, K.M.; Pai, Siddhesh; Pant, Brijesh; Sendhil Raja, S.; Gupta, P.K.

    2011-01-01

    A non-contact metrology system for inspection of FBTR fuel pins has been developed. The system consists of a stepper motors driven mechanism for orientation and positioning of FBTR fuel pin, a telecentric imaging system, absolute linear encoder with 0.1 μm resolution and a Field Programmable Gate Array (FPCA) based controller. The FBTR pin assembly is telecentrically illuminated from bottom by a red LED and its shadow graph is imaged using a CCD camera through telecentric imaging lens system. For system control and automation we have used a FPGA that has integrated soft picoblaze processor, X-θ axis motion controller, custom IPs for encoder data acquisition, synchronization circuit, RS485 interface along with other l/Os. Using the Graphical User Interface (GUI) on a PC the system is initialized at home position and the controller provides the trigger signal for start of data acquisition of CCD camera. CCD image of pin and the corresponding X-θ information is captured. After the acquisition of one set of images, the imaging module is moved with a step size pre-programmed to ensure proper stitching of acquired images. The GUI is programmed to analyze these X-θ Images to calculate the required parameters of the fuel pin like the diameter variation, pitch and bow. The details of the instrument and measurements made with it will be presented. (author)

  18. Silicide Schottky Contacts to Silicon: Screened Pinning at Defect Levels

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, T.J.

    1999-03-11

    Silicide Schottky contacts can be as large as 0.955 eV (E{sub v} + 0.165 eV) on n-type silicon and as large as 1.05 eV (E{sub c} {minus} 0.07 eV) on p-type silicon. Current models of Schottky barrier formation do not provide a satisfactory explanation of occurrence of this wide variation. A model for understanding Schottky contacts via screened pinning at defect levels is presented. In the present paper it is shown that most transition metal silicides are pinned approximately 0.48 eV above the valence band by interstitial Si clusters. Rare earth disilicides pin close to the divacancy acceptor level 0.41 eV below the conduction band edge while high work function silicides of Ir and Pt pin close to the divacancy donor level 0.21 eV above the valence band edge. Selection of a particular defect pinning level depends strongly on the relative positions of the silicide work function and the defect energy level on an absolute energy scale.

  19. Performance of electrical contact pins near a nuclear explosion

    International Nuclear Information System (INIS)

    Ragan, C.E.; Silbert, M.G.; Ellis, A.N.; Robinson, E.E.; Daddario, M.J.

    1977-09-01

    The pressures attainable in equation-of-state studies using nuclear-explosion-driven shock waves greatly exceed those that can be reached in normal laboratory conditions. However, the diagnostic instrumentation must survive in the high-radiation environment present near such an explosion. Therefore, a set of experiments were fielded on the Redmud event to test the feasibility of using electrical contact pins in this environment. In these experiments a 60-cm-high shield of boron-lead was placed on the rack lid approximately 1 m from the device. A sample consisting of slabs of molybdenum and 238 U was placed on top of the shield, and twelve electrical contact pins were embedded to five different depths in the materials. Five different multiplexing-charging circuits were used for the pins, and a piezoelectric quartz gauge was placed on top of the uranium to obtain an estimate of the fission-energy deposition. All of the charged pins survived the radiation and produced signals indicating shock arrival. The uncertainty in determining the pin-closure time was approximately 3 ns. The signal from the quartz gauge corresponded to a pressure that was consistent with the calculated neutron fluence

  20. Cluster synchronization for directed community networks via pinning partial schemes

    International Nuclear Information System (INIS)

    Hu Cheng; Jiang Haijun

    2012-01-01

    Highlights: ► Cluster synchronization for directed community networks is proposed by pinning partial schemes. ► Each community is considered as a whole. ► Several novel pinning criteria are derived based on the information of communities. ► A numerical example with simulation is provided. - Abstract: In this paper, we focus on driving a class of directed networks to achieve cluster synchronization by pinning schemes. The desired cluster synchronization states are no longer decoupled orbits but a set of un-decoupled trajectories. Each community is considered as a whole and the synchronization criteria are derived based on the information of communities. Several pinning schemes including feedback control and adaptive strategy are proposed to select controlled communities by analyzing the information of each community such as indegrees and outdegrees. In all, this paper answers several challenging problems in pinning control of directed community networks: (1) What communities should be chosen as controlled candidates? (2) How many communities are needed to be controlled? (3) How large should the control gains be used in a given community network to achieve cluster synchronization? Finally, an example with numerical simulations is given to demonstrate the effectiveness of the theoretical results.

  1. Irradiation of TZM: Uranium dioxide fuel pin at 1700 K

    Science.gov (United States)

    Mcdonald, G. E.

    1973-01-01

    A fuel pin clad with TZM and containing solid pellets of uranium dioxide was fission heated in a static helium-cooled capsule at a maximum surface temperature of 1700 K for approximately 1000 hr and to a total burnup of 2.0 percent of the uranium-235. The results of the postirradiation examination indicated: (1) A transverse, intergranular failure of the fuel pin occurred when the fuel pin reached 2.0-percent burnup. This corresponds to 1330 kW-hr/cu cm, where the volume is the sum of the fuel, clad, and void volumes in the fuel region. (2) The maximum swelling of the fuel pin was less than 1.5 percent on the fuel-pin diameter. (3) There was no visible interaction between the TZM clad and the UO2. (4) Irradiation at 1700 K produced a course-grained structure, with an average grain diameter of 0.02 centimeter and with some of the grains extending one-half of the thickness of the clad. (5) Below approximately 1500 K, the irradiation of the clad produced a moderately fine-grained structure, with an average grain diameter of 0.004 centimeter.

  2. Broad Temperature Pinning Study of 15 mol.% Zr-Added (Gd, Y)-Ba-Cu-O MOCVD Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, AX; Khatri, N; Liu, YH; Majkic, G; Galstyan, E; Selvamanickam, V; Chen, YM; Lei, CH; Abraimov, D; Hu, XB; Jaroszynski, J; Larbalestier, D

    2015-06-01

    BaZrO3 (BZO) nanocolumns have long been shown to be very effective for raising the pinning force F-p of REBa2Cu3Ox (REBCO, where RE = rare earth) films at high temperatures and recently at low temperatures too. We have successfully incorporated a high density of BZO nanorods into metal organic chemical vapor deposited (MOCVD) REBCO coated conductors via Zr addition. We found that, compared to the 7.5% Zr-added coated conductor, dense BZO nanorod arrays in the 15% Zr-added conductor are effective over the whole temperature range from 77 K down to 4.2 K. We attribute the substantially enhanced J(c) at 30 K to the weak uncorrelated pinning as well as the strong correlated pinning. Meanwhile, by tripling the REBCO layer thickness to similar to 2.8 mu m, the engineering critical current density J(e) at 30 K exceeds J(e) of optimized Nb-Ti wires at 4.2 K.

  3. Weakness

    Science.gov (United States)

    ... by a slipped disk in the spine) Stroke MUSCLE DISEASES Becker muscular dystrophy Dermatomyositis Muscular dystrophy (Duchenne) Myotonic dystrophy POISONING Botulism Poisoning ( insecticides , nerve gas) ...

  4. Cosmology with weak lensing surveys

    International Nuclear Information System (INIS)

    Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

    2008-01-01

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  5. Cosmology with weak lensing surveys

    Energy Technology Data Exchange (ETDEWEB)

    Munshi, Dipak [Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE (United Kingdom)], E-mail: munshi@ast.cam.ac.uk; Valageas, Patrick [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Waerbeke, Ludovic van [University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Heavens, Alan [SUPA - Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    2008-06-15

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  6. Peripheral facial weakness (Bell's palsy).

    Science.gov (United States)

    Basić-Kes, Vanja; Dobrota, Vesna Dermanović; Cesarik, Marijan; Matovina, Lucija Zadro; Madzar, Zrinko; Zavoreo, Iris; Demarin, Vida

    2013-06-01

    Peripheral facial weakness is a facial nerve damage that results in muscle weakness on one side of the face. It may be idiopathic (Bell's palsy) or may have a detectable cause. Almost 80% of peripheral facial weakness cases are primary and the rest of them are secondary. The most frequent causes of secondary peripheral facial weakness are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immune disorders, drugs, degenerative diseases of the central nervous system, etc. The diagnosis relies upon the presence of typical signs and symptoms, blood chemistry tests, cerebrospinal fluid investigations, nerve conduction studies and neuroimaging methods (cerebral MRI, x-ray of the skull and mastoid). Treatment of secondary peripheral facial weakness is based on therapy for the underlying disorder, unlike the treatment of Bell's palsy that is controversial due to the lack of large, randomized, controlled, prospective studies. There are some indications that steroids or antiviral agents are beneficial but there are also studies that show no beneficial effect. Additional treatments include eye protection, physiotherapy, acupuncture, botulinum toxin, or surgery. Bell's palsy has a benign prognosis with complete recovery in about 80% of patients, 15% experience some mode of permanent nerve damage and severe consequences remain in 5% of patients.

  7. Quantum discord with weak measurements

    International Nuclear Information System (INIS)

    Singh, Uttam; Pati, Arun Kumar

    2014-01-01

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength

  8. Reirradiation of mixed-oxide fuel pins at increased temperatures

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Weber, E.T.

    1976-05-01

    Mixed-oxide fuel pins from EBR-II irradiations were reirradiated in the General Electric Test Reactor (GETR) at higher temperatures than experienced in EBR-II to study effects of the increased operating temperatures on thermal/mechanical and chemical behavior. The response of a mixed-oxide fuel pin to a power increase after having operated at a lower power for a significant portion of its life-time is an area of performance evaluation where little information currently exists. Results show that the cladding diameter changes resulting from the reirradiation are strongly dependent upon both prior burnup level and the magnitude of the temperature increase. Results provide the initial rough outlines of boundaries within which mixed-oxide fuel pins can or cannot tolerate power increases after substantial prior burnup at lower powers

  9. Pin Tool Geometry Effects in Friction Stir Welding

    Science.gov (United States)

    Querin, J. A.; Rubisoff, H. A.; Schneider, J. A.

    2009-01-01

    In friction stir welding (FSW) there is significant evidence that material can take one of two different flow paths when being displaced from its original position in front of the pin tool to its final position in the wake of the weld. The geometry of the pin tool, along with the process parameters, plays an important role in dictating the path that the material takes. Each flow path will impart a different thermomechanical history on the material, consequently altering the material microstructure and subsequent weld properties. The intention of this research is to isolate the effect that different pin tool attributes have on the flow paths imparted on the FSWed material. Based on published weld tool geometries, a variety of weld tools were fabricated and used to join AA2219. Results from the tensile properties and microstructural characterization will be presented.

  10. Control of Flux Pinning in MOD YBCO Coated Conductor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W. [American Superconductor Corporation, Westborough, MA; Huang, Y. [American Superconductor Corporation, Westborough, MA; Li, X. [American Superconductor Corporation, Westborough, MA; Kodenkandath, Thomas [American Superconductor Corporation, Westborough, MA; Rupich, Marty [American Superconductor Corporation, Westborough, MA; Schoop, U. [American Superconductor Corporation, Westborough, MA; Verebelyi, D. T. [American Superconductor Corporation, Westborough, MA; Thieme, C. L. H. [American Superconductor Corporation, Westborough, MA; Siegal, E. E. [American Superconductor Corporation, Westborough, MA; Holesinger, T. G. [Los Alamos National Laboratory (LANL); Maiorov, B. [Los Alamos National Laboratory (LANL); Miller, D. J. [Argonne National Laboratory (ANL); Maroni, V. A. [Argonne National Laboratory (ANL); Goyal, Amit [ORNL; Specht, Eliot D [ORNL; Paranthaman, Mariappan Parans [ORNL

    2007-01-01

    Two different types of defect structures have been identified to be responsible for the enhanced pinning in metal organic deposited YBCO films. Rare earth additions result in the formation of nanodots in the YBCO matrix, which form uncorrelated pinning centers, increasing pinning in all magnetic field orientations. 124-type intergrowths, which form as laminar structures parallel to the ab-plane, are responsible for the large current enhancement when the magnetic field is oriented in the ab-plane. TEM studies showed that the intergrowths emanate from cuprous containing secondary phase particles, whose density is partially controlled by the rare earth doping level. Critical process parameters have been identified to control this phase formation, and therefore, control the f 24 intergrowth formation. This work has shown that through process control and proper conductor design, either by adjusting the composition or by multiple coatings of different functional layers, the desired angular dependence can be achieved.

  11. Control of flux pinning in MOD YBCO coated conductor.

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Huang, Y.; Li, X.; Kodenkandath, T.; Rupich, M. W.; Schoop, U.; Verebelyi, D. T.; Thieme, C. L. H.; Siegal, E.; Holesinger, T. G.; Maiorov, B.; Civale, L.; Miller, D. J.; Maroni, V. A.; Li, J.; Martin, P. M.; Specht, E. D.; Goyal, A.; Paranthaman, M. P.; American Superconductor Corp.; LANL; ORNL

    2007-06-01

    NTwo different types of defect structures have been identified to be responsible for the enhanced pinning in metal organic deposited YBCO films. Rare earth additions result in the formation of nanodots in the YBCO matrix, which form uncorrelated pinning centers, increasing pinning in all magnetic field orientations. 124-type intergrowths, which form as laminar structures parallel to the ab-plane, are responsible for the large current enhancement when the magnetic field is oriented in the ab-plane. TEM studies showed that the intergrowths emanate from cuprous containing secondary phase particles, whose density is partially controlled by the rare earth doping level. Critical process parameters have been identified to control this phase formation, and therefore, control the f 24 intergrowth formation. This work has shown that through process control and proper conductor design, either by adjusting the composition or by multiple coatings of different functional layers, the desired angular dependence can be achieved.

  12. Practical synchronization on complex dynamical networks via optimal pinning control

    Science.gov (United States)

    Li, Kezan; Sun, Weigang; Small, Michael; Fu, Xinchu

    2015-07-01

    We consider practical synchronization on complex dynamical networks under linear feedback control designed by optimal control theory. The control goal is to minimize global synchronization error and control strength over a given finite time interval, and synchronization error at terminal time. By utilizing the Pontryagin's minimum principle, and based on a general complex dynamical network, we obtain an optimal system to achieve the control goal. The result is verified by performing some numerical simulations on Star networks, Watts-Strogatz networks, and Barabási-Albert networks. Moreover, by combining optimal control and traditional pinning control, we propose an optimal pinning control strategy which depends on the network's topological structure. Obtained results show that optimal pinning control is very effective for synchronization control in real applications.

  13. Symmetric Pin Diversion Detection using a Partial Defect Detector (PDET)

    International Nuclear Information System (INIS)

    Sitaraman, S.; Ham, Y.S.

    2009-01-01

    Since the signature from the Partial Defect Detector (PDET) is principally dependent on the geometric layout of the guide tube locations, the capability of the technique in detecting symmetric diversion of pins needs to be determined. The Monte Carlo simulation study consisted of cases where pins were removed in a symmetric manner and the resulting signatures were examined. In addition to the normalized gamma-to-neutron ratios, the neutron and gamma signatures normalized to their maximum values, were also examined. Examination of the shape of the three curves as well as of the peak-to-valley differences in excess of the maximum expected in intact assemblies, indicated pin diversion. A set of simulations with various symmetric patterns of diversion were examined. The results from these studies indicated that symmetric diversions as low as twelve percent could be detected by this methodology

  14. Flux pinning in La70 Cu30 disordered system

    International Nuclear Information System (INIS)

    Esquinazi, P.; Guillet, B.; Dussell, H.

    1983-09-01

    Superconducting critical currents were measured as a function of a perpendicular applied magnetic field in disordered La 70 Cu 30 . It is shown that the pinning force is very sensitive to inhomogeneties already present in the as quenched samples, although these inhomogeneties have no obvious influence on other superconducting and transport properties. A simple series resistance model is used to explain the magnetic field dependence of the pinning force. A large decrease of the pinning force was obtained for the annealed samples. This behaviour is consistent with the phase separation model that explains the evolution of the superconductive penetration depth. In order to obtain a better characterization of the structural evolution with annealing of the La 70 Cu 30 system, behaviour of the electrical resistivity, superconducting critical temperature and differential thermal analysis were measured. (author)

  15. Radiation detectors of PIN type for X-rays

    International Nuclear Information System (INIS)

    Ramirez-Jimenez, F.J.

    2003-01-01

    In this laboratory session, tree experiments are proposed: the measurement of X-ray energy spectra from radioactive sources with a high resolution cooled Si-Li detector, with a room temperature PIN diode and the measurement of the response of a PIN diode to the intensity of X-rays of radio-diagnostic units. The spectra obtained with the Si-Li detector help to understand the energy distribution of X-rays and are used as a reference to compare the results obtained with the PIN diode. Measurements in medical X-ray machines are proposed. Low cost, simple electronic instruments and systems are used as tools to make measurements in X-ray units used in radio-diagnostic

  16. Development of wire wrapping technology for FBR fuel pin

    International Nuclear Information System (INIS)

    Nogami, Tetsuya; Seki, Nobuo; Sawayama, Takeo; Ishibashi, Takashi

    1991-01-01

    For the FBR fuel assembly, the spacer wire is adopted to maintain the space between fuel pins. The developments have been carried out to achieve automatically wire wrapping with high precision. Based on the fundamental technology developed through the mock-up test operation, Joyo 'MK-I', fuel pin fabrication was started using partially mechanized wire wrapping machine in 1973. In 1978, an automated wire wrapping machine for Joyo 'MK-II' was developed by the adoption of some improvements for the wire inserting system to end plug hole and the precision of wire pitch. On the bases of these experiences, fully automated wire wrapping machine for 'Monju' fuel pin was installed at Plutonium Fuel Production Facility (PFPF) in 1987. (author)

  17. Component Pin Recognition Using Algorithms Based on Machine Learning

    Science.gov (United States)

    Xiao, Yang; Hu, Hong; Liu, Ze; Xu, Jiangchang

    2018-04-01

    The purpose of machine vision for a plug-in machine is to improve the machine’s stability and accuracy, and recognition of the component pin is an important part of the vision. This paper focuses on component pin recognition using three different techniques. The first technique involves traditional image processing using the core algorithm for binary large object (BLOB) analysis. The second technique uses the histogram of oriented gradients (HOG), to experimentally compare the effect of the support vector machine (SVM) and the adaptive boosting machine (AdaBoost) learning meta-algorithm classifiers. The third technique is the use of an in-depth learning method known as convolution neural network (CNN), which involves identifying the pin by comparing a sample to its training. The main purpose of the research presented in this paper is to increase the knowledge of learning methods used in the plug-in machine industry in order to achieve better results.

  18. FFTF/IEM cell fuel pin weighing system

    International Nuclear Information System (INIS)

    Gibbons, P.W.

    1987-01-01

    The Interim Examination and Maintenance (IEM) cell in the Fast Flux Test Facility (FFTF) is used for remote disassembly of irradiated fuel and materials experiments. For those fuel experiments where the FFTF tag-gas detection system has indicated a fuel pin cladding breach, a weighing system is used in identifying that fuel pin with a reduced weight due to the escape of gaseous and volatile fission products. A fuel pin weighing machine, originally purchased for use in the Fuels and Materials Examination Facility (FMEF), was the basis for the IEM cell system. Design modifications to the original equipment were centered around adapting the machine to the differences between the two facilities and correcting deficiencies discovered during functional testing in the IEM cell mock-up

  19. Fabrication of Fast Reactor Fuel Pins for Test Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Karsten, G. [Institute for Applied Reactor Physics, Kernforschungszentrum Karlsruhe, Karlsruhe, Federal Republic of Germany (Germany); Dippel, T. [Institute for Radiochemistry, Kernforschungszentrum Karlsruhe, Karlsruhe, Federal Republic of Germany (Germany); Laue, H. J. [Institute for Applied Reactor Physics, Kernforschungszentrum Karlsruhe, Karlsruhe, Federal Republic of Germany (Germany)

    1967-09-15

    An extended irradiation programme is being carried out for the fuel element development of the Karlsruhe fast breeder project. A very important task within the programme is the testing of plutonium-containing fuel pins in a fast-reactor environment. This paper deals with fabrication of such pins by our laboratories at Karlsruhe. For the fast reactor test positions at present envisaged a fuel with 15% plutonium and the uranium fully enriched is appropriate. Hie mixed oxide is both pelletized and vibro-compacted with smeared densities between 80 and 88% theoretical. The pin design is, for example, such that there are two gas plena at the top and bottom, and one blanket above the fuel with the fuel zone fitting to the test reactor core length. The specifications both for fuel and cladding have been adapted to the special purpose of a fast-breeder reactor - the outer dimensions, the choice of cladding and fuel types, the data used and the kind of tests outline the targets of the development. The fuel fabrication is described in detail, and also the powder line used for vibro-compaction. The source materials for the fuel are oxalate PuO{sub 2} and UO{sub 2} from the UF{sub 6} process. The special problems of mechanical mixing and of plutonium homogeneity have been studied. The development of the sintering technique and grain characteristics for vibratory compactive fuel had to overcome serious problems in order to reach 82-83% theoretical. The performance of the pin fabrication needed a major effort in welding, manufacturing of fits and decontamination of the pin surfaces. This was a stimulation for the development of some very subtle control techniques, for example taking clear X-ray photographs and the tube testing. In general the selection of tests was a special task of the production routine. In conclusion the fabrication of the pins resulted in valuable experiences for the further development of fast reactor fuel elements. (author)

  20. Velocity distribution measurement in wire-spaced fuel pin bundle

    International Nuclear Information System (INIS)

    Mizuta, Hiroshi; Ohtake, Toshihide; Uruwashi, Shinichi; Takahashi, Keiichi

    1974-01-01

    Flow distribution measurement was made in the subchannels of a pin bundle in air flow. The present paper is interim because the target of this work is the decision of temperature of the pin surface in contact with wire spacers. The wire-spaced fuel pin bundle used for the experiment consists of 37 simulated fuel pins of stainless steel tubes, 3000 mm in length and 31.6 mm in diameter, which are wound spirally with 6 mm stainless steel wire. The bundle is wrapped with a hexagonal tube, 3500 mm in length and 293 mm in flat-to-flat distance. The bundle is fixed with knock-bar at the entrance of air flow in the hexagonal tube. The pitch of pins in the bundle is 37.6 mm (P/D=1.19) and the wrapping pitch of wire is 1100 mm (H/D=34.8). A pair of arrow-type 5-hole Pitot tubes are used to measure the flow velocity and the direction of air flow in the pin bundle. The measurement of flow distribution was made with the conditions of air flow rate of 0.33 m 3 /sec, air temperature of 45 0 C, and average Reynolds number of 15100 (average air velocity of 20.6 m/sec.). It was found that circular flow existed in the down stream of wire spacers, that axial flow velocity was slower in the subchannels, which contained wire spacers, than in those not affected by the wire, and that the flow angle to the axial velocity at the boundary of subchannels was two thirds smaller than wire wrapping angle. (Tai, I.)

  1. Weak-interacting holographic QCD

    International Nuclear Information System (INIS)

    Gazit, D.; Yee, H.-U.

    2008-06-01

    We propose a simple prescription for including low-energy weak-interactions into the frame- work of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. As our proposal enables us to calculate various electro-weak observables involving strongly coupled QCD, it opens a new perspective on phenomenological applications of holographic QCD. We illustrate efficiency and usefulness of our method by performing a few exemplar calculations; neutron beta decay, charged pion weak decay, and meson-nucleon parity non-conserving (PNC) couplings. The idea is general enough to be implemented in both Sakai-Sugimoto as well as Hard/Soft Wall models. (author)

  2. Plane waves with weak singularities

    International Nuclear Information System (INIS)

    David, Justin R.

    2003-03-01

    We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)

  3. Method and apparatus for enhancing vortex pinning by conformal crystal arrays

    Science.gov (United States)

    Janko, Boldizsar; Reichhardt, Cynthia; Reichhardt, Charles; Ray, Dipanjan

    2015-07-14

    Disclosed is a method and apparatus for strongly enhancing vortex pinning by conformal crystal arrays. The conformal crystal array is constructed by a conformal transformation of a hexagonal lattice, producing a non-uniform structure with a gradient where the local six-fold coordination of the pinning sites is preserved, and with an arching effect. The conformal pinning arrays produce significantly enhanced vortex pinning over a much wider range of field than that found for other vortex pinning geometries with an equivalent number of vortex pinning sites, such as random, square, and triangular.

  4. Pinning synchronization of delayed complex dynamical networks with nonlinear coupling

    Science.gov (United States)

    Cheng, Ranran; Peng, Mingshu; Yu, Weibin

    2014-11-01

    In this paper, we find that complex networks with the Watts-Strogatz or scale-free BA random topological architecture can be synchronized more easily by pin-controlling fewer nodes than regular systems. Theoretical analysis is included by means of Lyapunov functions and linear matrix inequalities (LMI) to make all nodes reach complete synchronization. Numerical examples are also provided to illustrate the importance of our theoretical analysis, which implies that there exists a gap between the theoretical prediction and numerical results about the minimum number of pinning controlled nodes.

  5. Creep relaxation of fuel pin bending and ovalling stresses

    International Nuclear Information System (INIS)

    Chan, D.P.; Jackson, R.J.

    1979-06-01

    Analytical methods for calculating fuel pin cladding bending and ovalling stresses due to pin bundle-duct mechanical interaction taking into account nonlinear creep are presented. Calculated results are in close agreement with finite element results by MARC-CDC program. The methods are used to investigate the effect of creep on the FTR fuel cladding bending and ovalling stresses. It is concluded that the cladding of 316 SS 20% CW and reference design has high creep rates in the FTR core region to keep the bending and ovalling stresses to low levels

  6. Nuclear fuel assemblies and fuel pins usable in such assemblies

    International Nuclear Information System (INIS)

    Jolly, R.

    1982-01-01

    A novel end cap for a nuclear fuel assembly is described in detail. It consists of a trisection arrangement which is received within a cell of a cellular grid. The cell contains abutment means with which the trisection comes into abutment. The grid also contains an abutment means for preventing the trisections from being inserted into the cell in an incorrect orientation. The present design allows fuel pins to be securely held in a hold-down grid of a sub-assembly. The design also allows easier dis-assembly of the swollen and embrittled fuel pins prior to reprocessing. (U.K.)

  7. 8 Pin RIC Socket for Hearing Aid Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Davids, Søren

    2012-01-01

    process and the other one is fully automated process. This paper presents the entire process chain for both the concepts and makes a comparative analysis based on the experimental investigation and validation. The work presented here can be a source of valuable information for industrial users...... of them. 8 Pin RIC Socket is a functionally versatile product which can combine many different functions and presents many advantages compared with the previous 3 Pin RIC Socket. For the demonstrator production of the new Socket, two different production concepts were chosen- one based on semi-automated...

  8. Fuel pin failure in the PFR/TREAT experiments

    International Nuclear Information System (INIS)

    Herbert, R.; Hunter, C.W.; Kramer, J.M.; Wood, M.H.; Wright, A.E.

    1986-01-01

    The PFR/TREAT safety testing programme involves the transient testing of fresh and pre-irradiated UK and US fuel pins. This paper summarizes the experimental and calculational results obtained to date on fuel pin failure during transient overpower (resulting from an accidental addition of resolivity) and transient undercooling followed by overpower (arising from an accidental stoppage of the primary sodium circulating pumps) accidents. Companion papers at this conference address: (I) the progress and future plans of the programme, and (II) post-failure material movements

  9. Influence of LMFBR fuel pin temperature profiles on corrosion rate

    International Nuclear Information System (INIS)

    Shiels, S.A.; Bagnall, C.; Schrock, S.L.; Orbon, S.J.

    1976-01-01

    The paper describes the sodium corrosion behavior of 20 percent cold worked Type 316 stainless steel fuel pin cladding under a simulated reactor thermal environment. A temperature gradient, typical of a fuel pin, was generated in a 0.9 m long heater section by direct resistance heating. Specimens were located in an isothermal test section immediately downstream of the heater. A comparison of the measured corrosion rates with available data showed an enhancement factor of between 1.5 and 2 which was attributed to the severe axial temperature gradient through the heater. Differences in structure and surface chemistry were also noted

  10. Establishment of the PIN within the Colombian party system

    Directory of Open Access Journals (Sweden)

    Vanessa Ortiz López

    2012-12-01

    Full Text Available This paper is a review of the legislative elections held in Colombia in 2010 and one of their main results, the establishment of the National Integration Party (PIN. The authors offer an analysis of articles that appeared in printed media, taking into consideration such variables as financing, legal constitution, popular acceptance and settling time. In this way, the authors attempt to demonstrate how the PIN managed to get a place in the political system and what are the consequences of this development, in particular, as the Department of Valle del Cauca is concerned.

  11. Analysis of the porosity distribution of mixed oxide pins

    International Nuclear Information System (INIS)

    Lieblich, M.; Lopez, J.

    1987-01-01

    In the frame of the Joint Irradiation Program IVO-FR2-Vg7 between the Centre of Nuclear Research of Karlsruhe (KfK), the irradiation of 30 mixed-oxide fuel rods in the FR2 experimental reactor was carried out. The pins were located in 10 single-walled NaK capsules. The behaviour of the fuel during its burnup was studied, mainly, the rest-porosity and cracking distribution in the pellet, partial densification, etc. In this work 3 pins from the capsule No. 165 were analyzed. The experimental results (pore and cracking profiles) were interpreted by the fuel rod code SATURN. (Author) 20 refs

  12. Closed reduction and fluoroscopic assisted percutaneous pinning of 42 physeal fractures in 37 dogs and 4 cats

    OpenAIRE

    Boekhout-Ta, Christina L; Kim, Stanley E; Corss, Alan R; Pozzi, Antonio; Evans, Richard

    2017-01-01

    OBJECTIVE: To report complications and clinical outcome of dogs and cats that underwent fluoroscopic-assisted percutaneous pinning (FAPP) of physeal fractures. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned dogs (n = 37) and cats (n = 4). MATERIALS AND METHODS: Records (August 2007-August 2014) of physeal fractures treated with FAPP in 3 hospitals were evaluated. Data collected included signalment, fracture characteristics (etiology, location, duration, Salter-Harris classi...

  13. Comparison of reconstructed radial pin total fission rates with experimental results in full scale BWR fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Giust, Flavio [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Nordostschweizerische Kraftwerke AG, Parkstrasse 23, CH-5401 Baden (Switzerland); Grimm, Peter; Jatuff, Fabian [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Chawla, Rakesh [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

    2008-07-01

    Total fission rate measurements have been performed on full size BWR fuel assemblies of type SVEA-96+ in the zero power reactor PROTEUS at the Paul Scherrer Institute. This work presents comparisons of reconstructed 2D pin fission rates in two configurations, I-1A and I-2A. Both configurations contain, in the central test zone, an array of 3x3 SVEA-96+ fuel elements moderated with light water at 20 deg. C. In configuration I-2A, an L-shaped hafnium control blade (half of a real cruciform blade) is inserted adjacent to the NW corner of the central fuel element. To minimize the impact of the surroundings, all measurements were done in fuel pins belonging to the central assembly. The 3x3 experimental configuration was modeled using the core monitoring and design tools that are applied at the Leibstadt Nuclear Power Plant (KKL). These are the 2D transport code HELIOS, used for the cross-section generation, and the 3D, 2-group nodal diffusion code PRESTO-2. The exterior is represented, in the axial and radial directions, by 2-group albedos calculated at the test zone boundary using a full-core 3D MCNPX model. The calculated-to-experimental (C/E) ratios of the total fission rates have a standard deviation of 1.3% in configuration I-1A (uncontrolled) and 3.2% in configuration I-2A (controlled). Sensitivity cases are analyzed to show the impact of certain parameters on the calculated fission rate distribution and reactivity. It is shown that the relative pin fission rate is only weakly dependent on these parameters. In cases without a control blade, the pin power reconstruction methodology delivers the same level of accuracy as 2D transport calculations. On the other hand, significant deviations, that are inherent to the use of reflected geometry in the lattice calculations, are observed in cases when the control blade is inserted. (authors)

  14. Cosmology and the weak interaction

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  15. Cosmology and the weak interaction

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N ν ∼ 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs

  16. Weak disorder in Fibonacci sequences

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Naim, E [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Krapivsky, P L [Department of Physics and Center for Molecular Cybernetics, Boston University, Boston, MA 02215 (United States)

    2006-05-19

    We study how weak disorder affects the growth of the Fibonacci series. We introduce a family of stochastic sequences that grow by the normal Fibonacci recursion with probability 1 - {epsilon}, but follow a different recursion rule with a small probability {epsilon}. We focus on the weak disorder limit and obtain the Lyapunov exponent that characterizes the typical growth of the sequence elements, using perturbation theory. The limiting distribution for the ratio of consecutive sequence elements is obtained as well. A number of variations to the basic Fibonacci recursion including shift, doubling and copying are considered. (letter to the editor)

  17. Weak interactions at high energies

    International Nuclear Information System (INIS)

    Ellis, J.

    1978-08-01

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references

  18. Overexpression of PvPin1, a Bamboo Homolog of PIN1-Type Parvulin 1, Delays Flowering Time in Transgenic Arabidopsis and Rice

    Directory of Open Access Journals (Sweden)

    Zhigang Zheng

    2017-09-01

    Full Text Available Because of the long and unpredictable flowering period in bamboo, the molecular mechanism of bamboo flowering is unclear. Recent study showed that Arabidopsis PIN1-type parvulin 1 (Pin1At is an important floral activator and regulates floral transition by facilitating the cis/trans isomerization of the phosphorylated Ser/Thr residues preceding proline motifs in suppressor of overexpression of CO 1 (SOC1 and agamous-like 24 (AGL24. Whether bamboo has a Pin1 homolog and whether it works in bamboo flowering are still unknown. In this study, we cloned PvPin1, a homolog of Pin1At, from Phyllostachys violascens (Bambusoideae. Bioinformatics analysis showed that PvPin1 is closely related to Pin1-like proteins in monocots. PvPin1 was widely expressed in all tested bamboo tissues, with the highest expression in young leaf and lowest in floral bud. Moreover, PvPin1 expression was high in leaves before bamboo flowering then declined during flower development. Overexpression of PvPin1 significantly delayed flowering time by downregulating SOC1 and AGL24 expression in Arabidopsis under greenhouse conditions and conferred a significantly late flowering phenotype by upregulating OsMADS56 in rice under field conditions. PvPin1 showed subcellular localization in both the nucleus and cytolemma. The 1500-bp sequence of the PvPin1 promoter was cloned, and cis-acting element prediction showed that ABRE and TGACG-motif elements, which responded to abscisic acid (ABA and methyl jasmonate (MeJA, respectively, were characteristic of P. violascens in comparison with Arabidopsis. On promoter activity analysis, exogenous ABA and MeJA could significantly inhibit PvPin1 expression. These findings suggested that PvPin1 may be a repressor in flowering, and its delay of flowering time could be regulated by ABA and MeJA in bamboo.

  19. Overexpression of PvPin1, a Bamboo Homolog of PIN1-Type Parvulin 1, Delays Flowering Time in Transgenic Arabidopsis and Rice.

    Science.gov (United States)

    Zheng, Zhigang; Yang, Xiaoming; Fu, Yaping; Zhu, Longfei; Wei, Hantian; Lin, Xinchun

    2017-01-01

    Because of the long and unpredictable flowering period in bamboo, the molecular mechanism of bamboo flowering is unclear. Recent study showed that Arabidopsis PIN1-type parvulin 1 (Pin1At) is an important floral activator and regulates floral transition by facilitating the cis/trans isomerization of the phosphorylated Ser/Thr residues preceding proline motifs in suppressor of overexpression of CO 1 (SOC1) and agamous-like 24 (AGL24). Whether bamboo has a Pin1 homolog and whether it works in bamboo flowering are still unknown. In this study, we cloned PvPin1 , a homolog of Pin1At , from Phyllostachys violascens (Bambusoideae). Bioinformatics analysis showed that PvPin1 is closely related to Pin1-like proteins in monocots. PvPin1 was widely expressed in all tested bamboo tissues, with the highest expression in young leaf and lowest in floral bud. Moreover, PvPin1 expression was high in leaves before bamboo flowering then declined during flower development. Overexpression of PvPin1 significantly delayed flowering time by downregulating SOC1 and AGL24 expression in Arabidopsis under greenhouse conditions and conferred a significantly late flowering phenotype by upregulating OsMADS56 in rice under field conditions. PvPin1 showed subcellular localization in both the nucleus and cytolemma. The 1500-bp sequence of the PvPin1 promoter was cloned, and cis -acting element prediction showed that ABRE and TGACG-motif elements, which responded to abscisic acid (ABA) and methyl jasmonate (MeJA), respectively, were characteristic of P. violascens in comparison with Arabidopsis . On promoter activity analysis, exogenous ABA and MeJA could significantly inhibit PvPin1 expression. These findings suggested that PvPin1 may be a repressor in flowering, and its delay of flowering time could be regulated by ABA and MeJA in bamboo.

  20. Measurement of the Weak Dipole Moments of the $\\tau$ Lepton

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1998-01-01

    Using the data collected by the L3 experiment at LEP from 1991 to 1995 at energies around the $\\Zo$ mass, a measurement of the weak anomalous magnetic dipole moment, $a^w_{\\tau}$,~ and of the weak electric dipole moment, $d^w_{\\tau}$, of the $\\tau$ lepton is performed. These quantities are obtained from angular distributions in $e^{+}e^{-}\\rightarrow\\tau^{+}\\tau^{-} \\rightarrow h^{+} \\bar{\

  1. Delayed Fission Product Gamma-Ray Transmission Through Low Enriched UO2 Fuel Pin Lattices in Air

    Energy Technology Data Exchange (ETDEWEB)

    Trumbull, TH [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2004-10-18

    The transmission of delayed fission-product gamma rays through various arrangements of low-enriched UO2 fuel pin lattices in an air medium was studied. Experimental measurements, point-kernel and Monte Carlo photon transport calculations were performed to demonstrate the shielding effect of ordered lattices of fuel pins on the resulting gamma-ray dose to a detector outside the lattice. The variation of the gamma-ray dose on the outside of the lattice as a function of radial position, the so-called “channeling” effect, was analyzed. Techniques for performing experimental measurements and data reduction at Rensselaer Polytechnic Institute’s Reactor Critical Facility (RCF) were derived. An experimental apparatus was constructed to hold the arrangements of fuel pins for the measurements. A gamma-ray spectroscopy system consisting of a sodium-iodide scintillation detector was used to collect data. Measurements were made with and without a collimator installed. A point-kernel transport code was developed to map the radial dependence of the gamma-ray flux. Input files for the Monte Carlo code, MCNP, were also developed to accurately model the experimental measurements. The results of the calculations were compared to the experimental measurements. In order to determine the delayed fission-product gamma-ray source for the calculations, a technique was developed using a previously written code, DELBG and the reactor state-point data obtained during the experimental measurements. Calculations were performed demonstrating the effects of material homogenization on the gamma-ray transmission through the fuel pin lattice.Homogeneous and heterogeneous calculations were performed for all RCF fuel pin lattices as well as for a typical commercial pressurized water reactor fuel bundle. The results of the study demonstrated the effectiveness of the experimental measurements to isolate the channeling effect of delayed fission-product gamma-rays through lattices of RCF fuel pins

  2. Vortex Dynamics in Superconductors with Different Types of Pinning Potentials; Dinamica de Vortices en Superconductores con Diferentes tipos de Anclaje

    Energy Technology Data Exchange (ETDEWEB)

    Laguna, Maria Fabiana [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, San Carlos de Bariloche (Argentina)

    2001-07-01

    of the solid phase and we determine the conditions for the existence of individual and collective pinning.

  3. Weak localization of seismic waves

    International Nuclear Information System (INIS)

    Larose, E.; Margerin, L.; Tiggelen, B.A. van; Campillo, M.

    2004-01-01

    We report the observation of weak localization of seismic waves in a natural environment. It emerges as a doubling of the seismic energy around the source within a spot of the width of a wavelength, which is several tens of meters in our case. The characteristic time for its onset is the scattering mean-free time that quantifies the internal heterogeneity

  4. On Weak-BCC-Algebras

    Science.gov (United States)

    Thomys, Janus; Zhang, Xiaohong

    2013-01-01

    We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983

  5. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.

    2017-01-01

    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  6. The structure of weak interaction

    International Nuclear Information System (INIS)

    Zee, A.

    1977-01-01

    The effect of introducing righthanded currents on the structure of weak interaction is discussed. The ΔI=1/2 rule is in the spotlight. The discussion provides an interesting example in which the so-called Iizuka-Okubo-Zweing rule is not only evaded, but completely negated

  7. Coverings, Networks and Weak Topologies

    Czech Academy of Sciences Publication Activity Database

    Dow, A.; Junnila, H.; Pelant, Jan

    2006-01-01

    Roč. 53, č. 2 (2006), s. 287-320 ISSN 0025-5793 R&D Projects: GA ČR GA201/97/0216 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach spaces * weak topologies * networks topologies Subject RIV: BA - General Mathematics

  8. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  9. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    effect of Pauli blocking, Fermi motion and renormalization of weak ∆ properties ... Furthermore, the angular distribution and the energy distribution of ... Here ψα(p ) and u(p) are the Rarita Schwinger and Dirac spinors for ∆ and nucleon.

  10. Weak transitions in 44Ca

    International Nuclear Information System (INIS)

    Tauhata, L.; Marques, A.

    1972-01-01

    Energy levels and gamma radiation transitions of Ca 44 are experimentally determined, mainly the weak transition at 564 KeV and 728 KeV. The decay scheme and the method used (coincidence with Ge-Li detector) are also presented [pt

  11. Evaluation of PWR and BWR pin cell benchmark results

    International Nuclear Information System (INIS)

    Pijlgroms, B.J.; Gruppelaar, H.; Janssen, A.J.; Hoogenboom, J.E.; Leege, P.F.A. de; Voet, J. van der; Verhagen, F.C.M.

    1991-12-01

    Benchmark results of the Dutch PINK working group on PWR and BWR pin cell calculational benchmark as defined by EPRI are presented and evaluated. The observed discrepancies are problem dependent: a part of the results is satisfactory, some other results require further analysis. A brief overview is given of the different code packages used in this analysis. (author). 14 refs., 9 figs., 30 tabs

  12. Evaluation of PWR and BWR pin cell benchmark results

    Energy Technology Data Exchange (ETDEWEB)

    Pijlgroms, B.J.; Gruppelaar, H.; Janssen, A.J. (Netherlands Energy Research Foundation (ECN), Petten (Netherlands)); Hoogenboom, J.E.; Leege, P.F.A. de (Interuniversitair Reactor Inst., Delft (Netherlands)); Voet, J. van der (Gemeenschappelijke Kernenergiecentrale Nederland NV, Dodewaard (Netherlands)); Verhagen, F.C.M. (Keuring van Electrotechnische Materialen NV, Arnhem (Netherlands))

    1991-12-01

    Benchmark results of the Dutch PINK working group on PWR and BWR pin cell calculational benchmark as defined by EPRI are presented and evaluated. The observed discrepancies are problem dependent: a part of the results is satisfactory, some other results require further analysis. A brief overview is given of the different code packages used in this analysis. (author). 14 refs., 9 figs., 30 tabs.

  13. Pinning and creep in high-Tc superconductors

    International Nuclear Information System (INIS)

    Ovchinnikov, Yu.N.; Ivlev, B.I.

    1992-01-01

    The angular and magnetic field dependence of a critical current parallel to the layers in the layered superconductors is studied. The critical current value is found for a superconductor with strong pinning centers. Quantum flux creep in sufficiently perfect layered high-Tc superconductors is discussed. The cross-over temperature between activated and quantum creep is found. (orig.)

  14. Percutaneous Pin Fixation of Gartland Type I11 Supraconylar ...

    African Journals Online (AJOL)

    S G Lungu M.Med (Orth). Specialist Orthopaedic Surgeon. Zambian Italian Orthopaedic Hospital, Lusaka. Key words: Percutaneous, pin fixation, Gartland type Ill, supracondylar, fractures, and humerus. This was a prospective study of 40 children with severely displaced (Gartland Type 111) supracondylar fractures of the ...

  15. Modeling the pinning of Au and Ni clusters on graphite

    NARCIS (Netherlands)

    Smith, R.; Nock, C.; Kenny, S.D.; Belbruno, J.J.; Di Vece, M.; Paloma, S.; Palmer, R.E.

    2006-01-01

    The pinning of size-selected AuN and NiN clusters on graphite, for N=7–100, is investigated by means of molecular dynamics simulations and the results are compared to experiment and previous work with Ag clusters. Ab initio calculations of the binding of the metal adatom and dimers on a graphite

  16. Flux pinning in MOD YBCO films by chemical doping

    International Nuclear Information System (INIS)

    Zhou, Y X; Ghalsasi, S; Rusakova, I; Salama, K

    2007-01-01

    A novel nanomaterial synthesis technique has been developed to introduce 0D (particles), 1D (columnar defects) and 3D (domains) nanoscale pinning centres in MOD Y 1 Ba 2 Cu 3 O 7 (YBCO) coated conductors. We have succeeded in introducing nanoscale Y enriched particles, nanoscale 90 0 rotated Y 1/3 Sm 2/3 Ba 2 Cu 3 O 7 domains and nanoscale Zr enriched columnar defects into YBCO layers by different chemical doping. The pinning force density in Y 2 O 3 -doped YBCO film is found to be larger than that of pure YBCO film at all fields. Also it was found that YBCO films with Sm substituting for Y have yielded improved critical current density characteristics over a wide range of magnetic fields. Maximum pinning force densities exceeding 7 and 8 GN m -3 are obtained in 5% BZO-doped and Sm substituted YBCO films, respectively. Additionally, TEM studies revealed nanoscale Zr enriched columnar defects distributing in the matrix of the c-oriented YBCO film throughout the whole cross section. This indicates that chemical doping is a promising fabrication technique to create specific pinning landscapes in YBCO coated conductors

  17. Flux vortex dynamics and electric fields in matched pinning systems

    International Nuclear Information System (INIS)

    Blamire, M.G.

    1987-01-01

    The pinning of flux vortices in type II superconductors has been the subject of extensive research. Certain experiments have attempted to investigate this problem by the use of specially prepared pinning structures consisting of regular arrays of pinning centers. In this paper a theory relating to such experiments is described. This theory is based on the existence and properties of defects in an otherwise perfect vortex lattice which is commensurate with a pinning array consisting of a triangular lattice of holes in a superconducting thin film. A quantitative treatment predicts the existence and position of substructure on the critical current versus magnetic field curves in addition to the main peaks previously predicted to occur when the vortex and hole lattices are exactly matched. The theory also qualitatively describes the overall shape of these curves. An analysis of the temperature dependence of this substructure shows broad agreement with existing experimental results. The application of this theory to future experiments should allow a detailed investigation of vortex lattice elasticity and flux flow

  18. Performance of advanced oxide fuel pins in EBR-II

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Jensen, S.M.; Hales, J.W.; Karnesky, R.A.; Makenas, B.J.

    1986-05-01

    The effects of design and operating parameters on mixed-oxide fuel pin irradiation performance were established for the Hanford Engineering Development Laboratory (HEDL) advanced oxide EBR-II test series. Fourteen fuel pins breached in-reactor with reference 316 SS cladding. Seven of the breaches are attributed to FCMI. Of the remaining seven breached pins, three are attributed to local cladding over-temperatures similar to the breach mechanism for the reference oxide pins irradiated in EBR-II. FCCI was found to be a contributing factor in two high burnup, i.e., 11.7 at. % breaches. The remaining two breaches were attributed to mechanical interaction of UO 2 fuel and fission products accumulated in the lower cladding insulator gap, and a loss of cladding ductility possibly due to liquid metal embrittlement. Fuel smear density appears to have the most significant impact on lifetime. Quantitative evaluations of cladding diameter increases attributed to FCMI, established fuel smear density, burnup, and cladding thickness-to-diameter ratio as the major parameters influencing the extent of cladding strain

  19. Image analysis for remote examination of fuel pins

    International Nuclear Information System (INIS)

    Cook, J.H.; Nayak, U.P.

    1982-01-01

    An image analysis system operating in the Wing 9 Hot Cell Facility at Los Alamos National Laboratory provides quantitative microstructural analyses of irradiated fuels and materials. With this system, fewer photomicrographs are required during postirradiation microstructural examination and data are available for analysis much faster. The system has been used successfully to examine Westinghouse Advanced Reactors Division experimental fuel pins

  20. Flux-Vortex Pinning and Neutron Star Evolution

    Indian Academy of Sciences (India)

    M. Ali Alpar

    2017-09-12

    Sep 12, 2017 ... M. ALI ALPAR. Faculty of Engineering and Natural Sciences, Sabancı University, 34956, Istanbul, Turkey. E-mail: ... netic field of the neutron star were B ∼ 109 G. At the ..... across pinning energy barriers by thermal activation.

  1. The behaviour of Phenix fuel pin bundle under irradiation

    International Nuclear Information System (INIS)

    Marbach, G.; Millet, P.; Blanchard, P.; Huillery, R.

    1979-07-01

    An entire Phenix sub-assembly has been mounted and sectioned after irradiation. The examination of cross-sections revealed the effects of mechanical interaction in the bundle (ovalisations and contacts between clads). According to analysis of the sodium channels, cooling of the pin bundle remained uniform. (author)

  2. Pin Tract Infection after Uniplanar External Fixation of Open ...

    African Journals Online (AJOL)

    ADMIN

    Regionally, a study by Jellis et al in Lusaka, Zambia, compared the rate of severe pin tract infection in HIV negative and positive ... likelihood of infection such as human immunodeficiency virus infection, diabetes mellitus, liver failure, renal failure, tumours ... Combined Open Tibia-Fibular. And Femur Fractures. 2. 2.7. Totals.

  3. Review of HEDL fuel pin transient analyses analytical programs

    International Nuclear Information System (INIS)

    Scott, J.H.; Baars, R.E.

    1975-05-01

    Methods for analysis of transient fuel pin performance are described, as represented by the steady-state SIEX code and the PECT series of codes used for steady-state and transient mechanical analyses. The empirical fuel failure correlation currently in use for analysis of transient overpower accidents is described. (U.S.)

  4. Propagation of spiral waves pinned to circular and rectangular obstacles.

    Science.gov (United States)

    Sutthiopad, Malee; Luengviriya, Jiraporn; Porjai, Porramain; Phantu, Metinee; Kanchanawarin, Jarin; Müller, Stefan C; Luengviriya, Chaiya

    2015-05-01

    We present an investigation of spiral waves pinned to circular and rectangular obstacles with different circumferences in both thin layers of the Belousov-Zhabotinsky reaction and numerical simulations with the Oregonator model. For circular objects, the area always increases with the circumference. In contrast, we varied the circumference of rectangles with equal areas by adjusting their width w and height h. For both obstacle forms, the propagating parameters (i.e., wavelength, wave period, and velocity of pinned spiral waves) increase with the circumference, regardless of the obstacle area. Despite these common features of the parameters, the forms of pinned spiral waves depend on the obstacle shapes. The structures of spiral waves pinned to circles as well as rectangles with the ratio w/h∼1 are similar to Archimedean spirals. When w/h increases, deformations of the spiral shapes are observed. For extremely thin rectangles with w/h≫1, these shapes can be constructed by employing semicircles with different radii which relate to the obstacle width and the core diameter of free spirals.

  5. Neutron radiography for quality assurance of PHWR fuel pins

    International Nuclear Information System (INIS)

    Chandrasekharan, K.N.; Patil, B.P.; Ghosh, J.K.; Ganguly, C.

    1993-01-01

    Neutron radiography was employed for quality assurance (QA) for advanced PHWR experimental fuel pins containing mixed uranium-plutonium dioxide and thorium-plutonium dioxide pellets. Direct, transfer and track-etch techniques were utilised. The thermal neutron beam facility of APSARA research reactor at Bhabha Atomic Research Centre was used. (author). 5 refs., 16 figs., 2 tabs

  6. Calculation of fuel pin failure timing under LOCA conditions

    International Nuclear Information System (INIS)

    Jones, K.R.; Wade, N.L.; Siefken, L.J.; Straka, M.; Katsma, K.R.

    1991-10-01

    The objective of this research was to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B ampersand W) design (Oconee) and a Westinghouse (W) 4-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin burnup, axial peaking factor, break size, emergency core cooling system (ECCS) availability, and main coolant pump trip on these items. The analysis was performed using a four-code approach, comprised of FRAPCON-2, SCDAP/RELAP5/MOD3, TRAC-PF1/MOD1, and FRAP-T6. In addition to the calculation of timing results, this analysis provided a comparison of the capabilities of SCDAP/RELAP5/MOD3 with TRAC-PF1/MOD1 for large-break LOCA analysis. This paper discusses the methodology employed and the code development efforts required to implement the methodology. The shortest time intervals calculated between initiation of containment isolation and fuel pin failure were 11.4 s and 19.1 for the B ampersand W and W plants, respectively. The FRAP-T6 fuel pin failure times calculated using thermal-hydraulic data generated by SCDAP/RELAP5/MOD3 were more conservative than those calculated using data generated by TRAC-PF1/MOD1. 18 refs., 7 figs., 4 tabs

  7. Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

    Directory of Open Access Journals (Sweden)

    Fengming Wang

    2012-12-01

    Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

  8. One- and two-dimension effects on fuel pin lifetime

    International Nuclear Information System (INIS)

    Stephen, J.D.; Biancheria, A.; Leibnitz, D.; O'Reilly, B.D.; Liu, Y.Y.; Labar, M.P.; Gneiting, B.C.

    1979-01-01

    Lifetime, or breach of the cladding, is a difficult performance limit to establish in fuel pin design. The significant benefits of high plant capacity factor favor conservative design to eliminate downtime or partial power operation caused by the breach limit; however, overly conservative design produces significant penalties. The LIFE system is being applied to help understand the range between operation and breach so that appropriate design margins can be selected. Standards are being developed in the USA to assure the structural integrity of all core components. These standards will provide guidelines to account for the failure mechanisms observed in the high temperature, high fluence core environment. The work to date indicates that creep rupture is the most important failure mechanism for mixed-oxide fuel pins during normal operation and slow power changes. The local cumulative creep rupture damage fraction (CDF) has been adopted as the parameter to assess the approach to failure. Several oxide breached pins and siblings have been studied For example, the P23B-73 pin was an FFTR driver design pin irradiated in EBR-II which failed at 10 at,% burnup. Initial evaluation based on LIFE3 led to the conclusion that the pin should not have failed. Further analyses determined the sensitivity of the breach prediction to the time-to-rupture correlation, cladding temperature, and fuel-fission product swelling (which had not been modeled in LIFE3). The uncertainties in the time-to-rupture correlation have been established. But LIFE is a one-dimensional model. The TWOD code is complete, and development of the best way to couple LIFE and TWOD for lifetime analysis is in progress. Two preliminary conclusions from analysis of representative oxide pin geometries are, first, that the circumferential stress distribution may not peak at the hot spot, but the damage (CDF) does. And second, that the effect of stress concentrations near fuel cracks on cladding creep damage is small

  9. Transfixation pinning and casting of radial-ulnar fractures in calves: A review of three cases

    OpenAIRE

    St-Jean, Guy; Debowes, Richard M.

    1992-01-01

    We reviewed the medical records of three calves with radial-ulnar fractures which were reduced and stabilized by transfixation pinning and casting. Multiple Steinmann pins were placed transversely through proximal and distal fracture fragments and the pin ends were incorporated in fiberglass cast material after fracture reduction. Cast material was placed from proximal to distal radius and served as an external frame to maintain pin position and fracture reduction.

  10. Serviceability of rod ceramic fuel pins on motoring conditions of FTP or NEMF reactor

    International Nuclear Information System (INIS)

    Deryavko, I.I.

    2004-01-01

    The operation conditions of rod ceramic fuel pins in the running hydrogen-cooled technological canals of FTP or NEMF reactor on the motoring conditions are considered. The available postreactor researches of the fuel pins are presented and the additional postreactor researches of fuel pins, tested on this mode in IVG.1 and IRGIT reactors, are carried out. The fuel pins serviceability on motoring conditions of FTP or NEF reactor operation is concluded. (author)

  11. New Universal Tribometer as Pin or Ball-on-Disc and Reciprocating Pin-on-Plate Types

    Directory of Open Access Journals (Sweden)

    H. Kaleli

    2016-06-01

    Full Text Available The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc. It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and high temperatures and boundary lubrication conditions of any typical gasoline or Diesel engines. Some friction results were shown in boundary lubricating conditions between piston ring and cylinder liner sliding pairs describing Tribotest machine is driven by AC servo motor which is more accurate than DC motor.

  12. Development of spectral history methods for pin-by-pin core analysis method using three-dimensional direct response matrix

    International Nuclear Information System (INIS)

    Mitsuyasu, T.; Ishii, K.; Hino, T.; Aoyama, M.

    2009-01-01

    Spectral history methods for pin-by-pin core analysis method using the three-dimensional direct response matrix have been developed. The direct response matrix is formalized by four sub-response matrices in order to respond to a core eigenvalue k and thus can be recomposed at each outer iteration in the core analysis. For core analysis, it is necessary to take into account the burn-up effect related to spectral history. One of the methods is to evaluate the nodal burn-up spectrum obtained using the out-going neutron current. The other is to correct the fuel rod neutron production rates obtained the pin-by-pin correction. These spectral history methods were tested in a heterogeneous system. The test results show that the neutron multiplication factor error can be reduced by half during burn-up, the nodal neutron production rates errors can be reduced by 30% or more. The root-mean-square differences between the relative fuel rod neutron production rate distributions can be reduced within 1.1% error. This means that these methods can accurately reflect the effects of intra- and inter-assembly heterogeneities during burn-up and can be used for core analysis. Core analysis with the DRM method was carried out for an ABWR quarter core and it was found that both thermal power and coolant-flow distributions were smoothly converged. (authors)

  13. Design fix for vibration-induced wear in fuel pin bundles

    International Nuclear Information System (INIS)

    Naas, D.F.; Heck, E.N.

    1976-01-01

    In summary, results at 45,000 MWd/MTM burnup from the FFTF mixed oxide fuel pin irradiation tests in EBR-II show that reduction of the initial fuel pin bundle clearance and use of 20 percent cold-worked stainless steel ducts virtually eliminate vibration and wear observed in an initial series of 61-pin tests

  14. The Effect of Insertion Technique on Temperatures for Standard and Self-Drilling External Fixation Pins.

    Science.gov (United States)

    Manoogian, Sarah; Lee, Adam K; Widmaier, James C

    2017-08-01

    No studies have assessed the effects of parameters associated with insertion temperature in modern self-drilling external fixation pins. The current study assessed how varying the presence of irrigation, insertion speed, and force impacted the insertion temperatures of 2 types of standard and self-drilling external fixation half pins. Seventy tests were conducted with 10 trials for 4 conditions on self-drilling pins, and 3 conditions for standard pins. Each test used a thermocouple inside the pin to measure temperature rise during insertion. Adding irrigation to the standard pin insertion significantly lowered the maximum temperature (P drilling pin tests dropped average rise in temperature from 151.3 ± 21.6°C to 124.1 ± 15.3°C (P = 0.005). When the self-drilling pin insertion was decreased considerably from 360 to 60 rpm, the temperature decreased significantly from 151.3 ± 21.6°C to 109.6 ± 14.0°C (P drilling pin temperature increase was not significant. The standard pin had lower peak temperatures than the self-drilling pin for all conditions. Moreover, slowing down the insertion speed and adding irrigation helped mitigate the temperature increase of both pin types during insertion.

  15. Use of a modified transfixation pin cast for treatment of comminuted phalangeal fractures in horses.

    Science.gov (United States)

    Rossignol, Fabrice; Vitte, Amélie; Boening, Josef

    2014-01-01

    To (1) report a modified transfixation pin cast technique, using dorsal recumbency for fracture reduction, distal positioning of the pins in the epiphysis and distal metaphysis, and a hybrid cast, combining plaster of Paris (POP) and fiberglass casting, and (2) report outcome in 11 adult horses. Case series. Adult horses (n = 11) with comminuted phalangeal fractures. Horses were anesthetized and positioned in dorsal recumbency. The phalangeal fracture was reduced by limb traction using a cable attached to the hoof. Screw fixation in lag fashion of fracture fragments was performed when possible. Transfixation casting was performed using two 6.3 mm positive profile centrally threaded pins with the 1st pin placed in the epiphysis of the metacarpus/tarsus at the center of, or slightly proximal to, the condylar fossa and the 2nd one 3-4 cm proximal. A hybrid cast was applied. Forelimbs were involved in 9 horses and the hind limb in 2. Pins were maintained for a minimum of 6 weeks. No pin loosening was observed at the time of removal (6-8 weeks). A pony fractured the distal aspect of the metacarpus at the proximal pin. Nine horses survived (82%); none of the horses developed septic arthritis despite the distal location of the distal pin, close to the fetlock joint. This modified transfixation pin casting technique was associated with good pin longevity and could reduce the risk of secondary pin hole fractures and pin loosening. © Copyright 2013 by The American College of Veterinary Surgeons.

  16. A pin-assisted retention technique for resin-bonded restorations.

    Science.gov (United States)

    Miara, P; Touati, B

    1992-09-01

    The value of pins for auxiliary retention has been demonstrated many times. The use of pins with resin-bonded restorations allows for improved aesthetics and less tooth reduction while increasing resistance to dislodging forces. Clinical and technical procedures for resin-bonded bridges with pin-assisted retention are presented.

  17. The PIN family of proteins in potato and their putative role in tuberisation

    Directory of Open Access Journals (Sweden)

    Efstathios eRoumeliotis

    2013-12-01

    Full Text Available The PIN family of trans-membrane proteins mediates auxin efflux throughout the plant and during various phases of plant development. In Arabidopsis thaliana, the PIN family comprised of 8 members, divided into ‘short’ and ‘long’ PINs according to the length of the hydrophilic domain of the protein. Based on sequence homology using the recently published potato genome sequence (Solanum tuberosum group Phureja we identified ten annotated potato StPIN genes. Mining the publicly available gene expression data, we constructed a catalogue tissue specificity of StPIN gene expression, focusing on the process of tuberization. A total of four StPIN genes exhibited increased expression four days after tuber induction, prior to the onset of stolon swelling. For two PIN genes, StPIN4 and StPIN2, promoter sequences were cloned and fused to the GUS reporter protein to study tissue specificity in more detail. StPIN4 promoter driven GUS staining was detected in the flower stigma, in the flower style, below the ovary and petals, in the root tips, in the vascular tissue of the stolons and in the tuber parenchyma cells. StPIN2 promoter driven GUS staining was detected in flower buds, in the vascular tissue of the swelling stolons and in the storage parenchyma of the growing tubers. Based on our results, we postulate a role for the StPINs in redistributing auxin in the swelling stolon during early events in tuber development.

  18. Light weakly interacting massive particles

    Science.gov (United States)

    Gelmini, Graciela B.

    2017-08-01

    Light weakly interacting massive particles (WIMPs) are dark matter particle candidates with weak scale interaction with the known particles, and mass in the GeV to tens of GeV range. Hints of light WIMPs have appeared in several dark matter searches in the last decade. The unprecedented possible coincidence into tantalizingly close regions of mass and cross section of four separate direct detection experimental hints and a potential indirect detection signal in gamma rays from the galactic center, aroused considerable interest in our field. Even if these hints did not so far result in a discovery, they have had a significant impact in our field. Here we review the evidence for and against light WIMPs as dark matter candidates and discuss future relevant experiments and observations.

  19. (Weakly) three-dimensional caseology

    International Nuclear Information System (INIS)

    Pomraning, G.C.

    1996-01-01

    The singular eigenfunction technique of Case for solving one-dimensional planar symmetry linear transport problems is extended to a restricted class of three-dimensional problems. This class involves planar geometry, but with forcing terms (either boundary conditions or internal sources) which are weakly dependent upon the transverse spatial variables. Our analysis involves a singular perturbation about the classic planar analysis, and leads to the usual Case discrete and continuum modes, but modulated by weakly dependent three-dimensional spatial functions. These functions satisfy parabolic differential equations, with a different diffusion coefficient for each mode. Representative one-speed time-independent transport problems are solved in terms of these generalised Case eigenfunctions. Our treatment is very heuristic, but may provide an impetus for more rigorous analysis. (author)

  20. History of the weak interactions

    International Nuclear Information System (INIS)

    Lee, T.D.

    1987-01-01

    At the 'Jackfest' marking the 65th birthday of Jack Steinberger (see July/August 1986 issue, page 29), T.D. Lee gave an account of the history of the weak interactions. This edited version omits some of Lee's tributes to Steinberger, but retains the impressive insight into the subtleties of a key area of modern physics by one who played a vital role in its development. (orig./HSI).

  1. Weak neutral-current interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references

  2. Submanifolds weakly associated with graphs

    Indian Academy of Sciences (India)

    A CARRIAZO, L M FERN ´ANDEZ and A RODRÍGUEZ-HIDALGO. Department of Geometry and Topology, ..... by means of trees (connected graphs without cycles) and forests (disjoint unions of trees, see [6]) given in [3], by extending it to weak ... CR-submanifold. In this case, every tree is a K2. Finally, Theorem 3.8 of [3] can ...

  3. Voltage-current characteristics of a pin-plate system with different plate configurations

    International Nuclear Information System (INIS)

    Feng, Zhuangbo; Long, Zhengwei

    2013-01-01

    In this paper, the voltage-current (V-I) characteristics of a pin-plate system with four types of collection plate configurations are studied experimentally. The collection plates consider a single metal plate, a metal plate with a fly ash cake layer, a metal plate with a clean filter media and a metal plate with a dirty filter media. The results show that the clean filter media has no obvious effect on the V-I characteristics. But the dirty filter media reduces the current density because of its high resistance. The thick fly ash cake layer increase current density because of the anti-corona effect but the increment is not very obvious.

  4. Probabilistic distributions of pin gaps within a wire-spaced fuel subassembly and sensitivities of the related uncertainties to pin gap

    International Nuclear Information System (INIS)

    Sakai, K.; Hishida, H.

    1978-01-01

    Probabilistic fuel pin gap distributions within a wire-spaced fuel subassembly and sensitivities of the related uncertainties to fuel pin gaps are discussed. The analyses consist mainly of expressing a local fuel pin gap in terms of sensitivity functions of the related uncertainties and calculating the corresponding probabilistic distribution through taking all the possible combinations of the distribution of uncertainties. The results of illustrative calculations show that with the reliability level of 0.9987, the maximum deviation of the pin gap at the cladding hot spot of a center fuel subassembly is 8.05% from its nominal value and the corresponding probabilistic pin gap distribution is shifted to the narrower side due to the external confinement of a pin bundle with a wrapper tube. (Auth.)

  5. Percutaneous external fixator pins with bactericidal micron-thin sol-gel films for the prevention of pin tract infection.

    Science.gov (United States)

    Qu, Haibo; Knabe, Christine; Radin, Shula; Garino, Jonathan; Ducheyne, Paul

    2015-09-01

    Risk of infection is considerable in open fractures, especially when fracture fixation devices are used to stabilize the fractured bones. Overall deep infection rates of 16.2% have been reported. The infection rate is even greater, up to 32.2%, with external fixation of femoral fractures. The use of percutaneous implants for certain clinical applications, such as percutaneous implants for external fracture fixation, still represents a challenge today. Currently, bone infections are very difficult to treat. Very potent antibiotics are needed, which creates the risk of irreversible damage to other organs, when the antibiotics are administered systemically. As such, controlled, local release is being pursued, but no such treatments are in clinical use. Herein, the use of bactericidal micron-thin sol-gel films on metallic fracture fixation pins is reported. The data demonstrates that triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether), an antimicrobial agent, can be successfully incorporated into micron-thin sol-gel films deposited on percutaneous pins. The sol-gel films continuously release triclosan in vitro for durations exceeding 8 weeks (longest measured time point). The bactericidal effect of the micron-thin sol-gel films follows from both in vitro and in vivo studies. Inserting percutaneous pins in distal rabbit tibiae, there were no signs of infection around implants coated with a micron-thin sol-gel/triclosan film. Healing had progressed normally, bone tissue growth was normal and there was no epithelial downgrowth. This result was in contrast with the results in rabbits that received control, uncoated percutaneous pins, in which abundant signs of infection and epithelial downgrowth were observed. Thus, well-adherent, micron-thin sol-gel films laden with a bactericidal molecule successfully prevented pin tract infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Systemic inflammatory response syndrome increases immobility-induced neuromuscular weakness.

    Science.gov (United States)

    Fink, Heidrun; Helming, Marc; Unterbuchner, Christoph; Lenz, Andrea; Neff, Frauke; Martyn, J A Jeevendra; Blobner, Manfred

    2008-03-01

    Inflammation and immobility are comorbid etiological factors inducing muscle weakness in critically ill patients. This study establishes a rat model to examine the effect of inflammation and immobilization alone and in combination on muscle contraction, histology, and acetylcholine receptor regulation. Prospective, randomized, experimental study. Animal laboratory of a university hospital. Sprague-Dawley rats. To produce systemic inflammation, rats (n = 34) received three consecutive intravenous injections of Corynebacterium parvum on days 0, 4, and 8. Control rats (n = 21) received saline. Both groups were further divided to have one hind limb either immobilized by pinning of knee and ankle joints or sham-immobilized (surgical leg). The contralateral nonsurgical leg of each animal served as control (nonsurgical leg). After 12 days, body weight and muscle mass were significantly reduced in all C. parvum animals compared with saline-injected rats. Immobilization led to local muscle atrophy. Normalized to muscle mass, tetanic contraction was reduced in the surgical leg after immobilization (7.64 +/- 1.91 N/g) and after inflammation (8.71 +/- 2.0 N/g; both p < .05 vs. sham immobilization and saline injection, 11.03 +/- 2.26 N/g). Histology showed an increase in inflammatory cells in all C. parvum-injected animals. Immobilization in combination with C. parvum injection had an additive effect on inflammation. Acetylcholine receptors were increased in immobilized muscles and in all muscles of C. parvum-injected animals. The muscle weakness in critically ill patients can be replicated in our novel rat model. Inflammation and immobilization independently lead to muscle weakness.

  7. Distribution of Endogenous NO Regulates Early Gravitropic Response and PIN2 Localization in Arabidopsis Roots

    Directory of Open Access Journals (Sweden)

    Ramiro París

    2018-04-01

    Full Text Available High-resolution and automated image analysis of individual roots demonstrated that endogenous nitric oxide (NO contribute significantly to gravitropism of Arabidopsis roots. Lowering of endogenous NO concentrations strongly reduced and even reversed gravitropism, resulting in upward bending, without affecting root growth rate. Notably, the asymmetric accumulation of NO along the upper and lower sides of roots correlated with a positive gravitropic response. Detection of NO by the specific DAF-FM DA fluorescent probe revealed that NO was higher at the lower side of horizontally-oriented roots returning to initial values 2 h after the onset of gravistimulation. We demonstrate that NO promotes plasma membrane re-localization of PIN2 in epidermal cells, which is required during the early root gravitropic response. The dynamic and asymmetric localization of both auxin and NO is critical to regulate auxin polar transport during gravitropism. Our results collectively suggest that, although auxin and NO crosstalk occurs at different levels of regulation, they converge in the regulation of PIN2 membrane trafficking in gravistimulated roots, supporting the notion that a temporally and spatially coordinated network of signal molecules could participate in the early phases of auxin polar transport during gravitropism.

  8. Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability

    Science.gov (United States)

    Kar, Soummya; Moura, José M. F.

    2011-04-01

    The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

  9. Why is gravity so weak?

    International Nuclear Information System (INIS)

    Goradia, S.G.

    2006-01-01

    Why is gravity weak? Gravity is plagued with this and many other questions. After decades of exhausting work we do not have a clear answer. In view of this fact it will be shown in the following pages that there are reasons for thinking that gravity is just a composite force consisting of the long-range manifestations of short range nuclear forces that are too tiny to be measured at illuminated or long ranges by particle colliders. This is consistent with Einstein's proposal in 1919

  10. Weak decays of heavy quarks

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1978-08-01

    The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references

  11. Weak consistency and strong paraconsistency

    Directory of Open Access Journals (Sweden)

    Gemma Robles

    2009-11-01

    Full Text Available In a standard sense, consistency and paraconsistency are understood as, respectively, the absence of any contradiction and as the absence of the ECQ (“E contradictione quodlibet” rule that allows us to conclude any well formed formula from any contradiction. The aim of this paper is to explain the concepts of weak consistency alternative to the standard one, the concepts of paraconsistency related to them and the concept of strong paraconsistency, all of which have been defined by the author together with José M. Méndez.

  12. Electromagnetic weak turbulence theory revisited

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)

    2012-10-15

    The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.

  13. Clinical and histomorphometrical study on titanium dioxide-coated external fixation pins.

    Science.gov (United States)

    Koseki, Hironobu; Asahara, Tomohiko; Shida, Takayuki; Yoda, Itaru; Horiuchi, Hidehiko; Baba, Koumei; Osaki, Makoto

    2013-01-01

    Pin site infection is the most common and significant complication of external fixation. In this work, the efficacy of pins coated with titanium dioxide (TiO(2)) for inhibition of infection was compared with that of stainless steel control pins in an in vivo study. Pins contaminated with an identifiable Staphylococcus aureus strain were inserted into femoral bone in a rat model and exposed to ultraviolet A light for 30 minutes. On day 14, the animals were sacrificed and the bone and soft tissue around the pin were retrieved. The clinical findings and histological findings were evaluated in 60 samples. Clinical signs of infection were present in 76.7% of untreated pins, but in only 36.7% of TiO(2)-coated pins. The histological bone infection score and planimetric rate of occupation for bacterial colonies and neutrophils in the TiO(2)-coated pin group were lower than those in the control group. The bone-implant contact ratio of the TiO(2)-coated pin group was significantly higher (71.4%) than in the control pin group (58.2%). The TiO(2) was successful in decreasing infection both clinically and histomorphometrically. The photocatalytic bactericidal effect of TiO(2) is thought to be useful for inhibiting pin site infection after external fixation.

  14. Wear-Induced Changes in FSW Tool Pin Profile: Effect of Process Parameters

    Science.gov (United States)

    Sahlot, Pankaj; Jha, Kaushal; Dey, G. K.; Arora, Amit

    2018-06-01

    Friction stir welding (FSW) of high melting point metallic (HMPM) materials has limited application due to tool wear and relatively short tool life. Tool wear changes the profile of the tool pin and adversely affects weld properties. A quantitative understanding of tool wear and tool pin profile is crucial to develop the process for joining of HMPM materials. Here we present a quantitative wear study of H13 steel tool pin profile for FSW of CuCrZr alloy. The tool pin profile is analyzed at multiple traverse distances for welding with various tool rotational and traverse speeds. The results indicate that measured wear depth is small near the pin root and significantly increases towards the tip. Near the pin tip, wear depth increases with increase in tool rotational speed. However, change in wear depth near the pin root is minimal. Wear depth also increases with decrease in tool traverse speeds. Tool pin wear from the bottom results in pin length reduction, which is greater for higher tool rotational speeds, and longer traverse distances. The pin profile changes due to wear and result in root defect for long traverse distance. This quantitative understanding of tool wear would be helpful to estimate tool wear, optimize process parameters, and tool pin shape during FSW of HMPM materials.

  15. Study of the Radiation-Hardness of VCSEL and PIN

    CERN Document Server

    Gan, K K; Fernando, W; Kagan, H P; Kass, R D; Lebbai, M R M; Merritt, H; Moore, J R; Nagarkar, A; Rizatdinova, F; Skubic, P L; Smith, D S; Strang, M

    2009-01-01

    The silicon trackers of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission. An upgrade of the trackers is planned for the Super LHC (SLHC), an upgraded LHC with ten times higher luminosity. We study the radiation-hardness of VCSELs (Vertical-Cavity Surface-Emitting Laser) and GaAs and silicon PINs using 24 GeV/c protons at CERN for possible application in the data transmission upgrade. The optical power of VCSEL arrays decreases significantly after the irradiation but can be partially annealed with high drive currents. The responsivities of the PIN diodes also decrease significantly after irradiation, but can be recovered by operating at higher bias voltage. This provides a simple mechanism to recover from the radiation damage.

  16. Performance of refractory alloy-clad fuel pins

    International Nuclear Information System (INIS)

    Dutt, D.S.; Cox, C.M.; Millhollen, M.K.

    1984-12-01

    This paper discusses objectives and basic design of two fuel-cladding tests being conducted in support of SP-100 technology development. Two of the current space nuclear power concepts use conventional pin type designs, where a coolant removes the heat from the core and transports it to an out-of-core energy conversion system. An extensive irradiation testing program was conducted in the 1950's and 1960's to develop fuel pins for space nuclear reactors. The program emphasized refractory metal clad uranium nitride (UN), uranium carbide (UC), uranium oxide (UO 2 ), and metal matrix fuels (UCZr and BeO-UO 2 ). Based on this earlier work, studies presented here show that UN and UO 2 fuels in conjunction with several refractory metal cladding materials demonstrated high potential for meeting space reactor requirements and that UC could serve as an alternative but higher risk fuel

  17. Flux-pinning-induced stress and magnetostriction in bulk superconductors

    International Nuclear Information System (INIS)

    Johansen, Tom H.

    2000-01-01

    The development of bulk high-temperature superconductors (HTSs) and their applications has today come to a point where the mechanical response to high magnetic fields may be more important than their critical-current density and large-grain property. Reviewed in this article are the recent studies of the magneto-elastic effects which are caused by flux pinning in the superconductors. This includes the work on the giant irreversible magnetostriction and internal stress, which often cause fatal cracking of the HTS bulks as they become magnetized. The cracking is a problem that today accompanies the quest for the highest trapped field values, and the latest development in this area is also presented. While the first part is an overview of experimental efforts, the second summarizes the work done to model the pinning-induced stress and strain under various magnetic and geometrical conditions. (author)

  18. Superconducting pinning in BCC niobium-base alloys

    International Nuclear Information System (INIS)

    Hu, S.

    1981-01-01

    The structure dependence of critical current density J/sub c/ in superconducting alloys Nb--Zr and Nb--Ti was studied by means of x-ray analysis and tensile test. Experimental results indicate that, in the absence of second phase particles, annealing increases J/sub c/ in deformed alloys due to rearrangement of dislocations into cell structure and the cell walls are effective pinning centers for magnetic flux. In the precipitation process of second phase particles, new dislocations are formed due to the relaxation of coherent stress field. These new dislocations increases the dislocation density and the flux pinning ability of the cell walls, which in turn lead to a further increase of J/sub c/. The mechanism that causes precipitates to increase the current-carrying ability in Nb--Zr and Nb--Ti alloys is therefore the same as that of cold-work deformation

  19. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    Science.gov (United States)

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  20. Magnetization pinning in conducting films demonstrated using broadband ferromagnetic resonance

    Science.gov (United States)

    Kostylev, M.; Stashkevich, A. A.; Adeyeye, A. O.; Shakespeare, C.; Kostylev, N.; Ross, N.; Kennewell, K.; Magaraggia, R.; Roussigné, Y.; Stamps, R. L.

    2010-11-01

    The broadband microstrip ferromagnetic resonance (FMR), cavity FMR, and Brillouin light scattering spectroscopy techniques have been applied for detection and characterization of a magnetic inhomogeneity in a film sample. In the case of a 100 nm thick permalloy film, an additional magnetically depleted top sublayer has been detected due to pinning effect it produces on the magnetization in the bulk of the film. The pinning results in appearance of an exchange standing spin wave mode in the broadband FMR absorption spectrum, whose amplitudes are different depending on whether the film or the film substrate faces the microstrip transducer. Comparison of the experimental amplitudes for this mode with results of our theory for both film placements revealed that the depleted layer is located at the film surface facing away from the film substrate. Subsequent broadband FMR characterization of a large number of other presumably single-layer films with thicknesses in the range 30-100 nm showed the same result.

  1. Leituras semióticas de Pinóquio

    Directory of Open Access Journals (Sweden)

    Rafael Giardini Lenzi

    2013-12-01

    Full Text Available Esta resenha faz breve exposição do conteúdo de Pinocchio: nuove avventure tra segni e linguaggi, organizado por Paolo Fabbri e Isabella Pezzini, que apresenta dez artigos e um tautograma que tratam do tema Pinóquio, alternando entre elementos do texto original, elementos presentes em variações do romance e abordagens sobre a tradução ou a variação em si, sob a óptica da semiótica discursiva. A perseverança e forte proliferação do tema Pinóquio, originalmente ou sob outros pontos de vista trazidos pelos meios de comunicação, estabelece o texto como uma fábula da atualidade que sempre atraiu o olhar científico.

  2. Intrinsic pinning in superconductors with extremely small coherence lengths

    International Nuclear Information System (INIS)

    Schimmele, L.; Kronmueller, H.; Teichler, H.

    1988-01-01

    By means of a Ginsburg-Landau-type theory which takes into account the discrete lattice structure the variation of the energy ('Peierls potential') of an isolated flux line is calculated when shifted relatively to the crystal lattice. In particular, a primitive cubic lattice is considered with a straight flux line, aligned parallel to a cubic axis. The resulting Peierls potential may lead to intrinsic pinning if the coherence length is smaller than about two nearest neighbour distances. The coherence lengths at low temperatures determined for the recently discovered high T c superconductors of the YBa 2 Cu 3 O 7 class come very close to this value so that intrinsic pinning might possibly be relevant for these superconductors. (author)

  3. Polarization of concave domains by traveling wave pinning.

    Directory of Open Access Journals (Sweden)

    Slawomir Bialecki

    Full Text Available Pattern formation is one of the most fundamental yet puzzling phenomena in physics and biology. We propose that traveling front pinning into concave portions of the boundary of 3-dimensional domains can serve as a generic gradient-maintaining mechanism. Such a mechanism of domain polarization arises even for scalar bistable reaction-diffusion equations, and, depending on geometry, a number of stationary fronts may be formed leading to complex spatial patterns. The main advantage of the pinning mechanism, with respect to the Turing bifurcation, is that it allows for maintaining gradients in the specific regions of the domain. By linking the instant domain shape with the spatial pattern, the mechanism can be responsible for cellular polarization and differentiation.

  4. Design and Operation of 3-Pin FTL HVAC System

    International Nuclear Information System (INIS)

    Chi, D. Y.; Sim, B. S.; Park, S. K.; Park, K. N.; Lee, J. M.; Ahn, S. H.; Lee, C. Y.; Kim, Y. J.

    2005-01-01

    According to the increasing demand for irradiation tests to develop new fuels, the 3-Pin FTL(Fuel Test Loop for 3 pin test fuel) facility has now been under design to conduct in-core fuel performance tests at the operating conditions, which will be installed at HANARO. The HVAC system of the FTL will be dependent on that of the HANARO. The FTL has three equipments rooms, which are the room 1, room 2 and the control room. The high pressure and high temperature equipments will be installed in the room 1. The atmosphere of the room 1 shall be maintained under the designed condition. This paper describes the design of the FTL HVAC system in the room 1

  5. Exponential synchronization of complex delayed dynamical networks via pinning periodically intermittent control

    Energy Technology Data Exchange (ETDEWEB)

    Cai Shuiming, E-mail: caishuiming2008@yahoo.com.c [Department of Mathematics, Shanghai University, Shanghai 200444 (China); Institute of System Biology, Shanghai University, Shanghai 200444 (China); Hao Junjun [Institute of System Biology, Shanghai University, Shanghai 200444 (China); He, Qinbin [Department of Mathematics, Taizhou University, Linhai 317000 (China); Institute of System Biology, Shanghai University, Shanghai 200444 (China); Liu Zengrong, E-mail: zrongliu@126.co [Department of Mathematics, Shanghai University, Shanghai 200444 (China) and Institute of System Biology, Shanghai University, Shanghai 200444 (China)

    2011-05-09

    The problem of synchronization for a class of complex delayed dynamical networks via pinning periodically intermittent control is considered in this Letter. Some novel and useful exponential synchronization criteria are obtained by utilizing the methods which are different from the techniques employed in the existing works, and the derived results are less conservative. Especially, the traditional assumptions on control width and time delays are released in our results. Moreover, a pinning scheme deciding what nodes should be chosen as pinned candidates and how many nodes are needed to be pinned for a fixed coupling strength is provided. A Barabasi-Albert network example is finally given to illustrate the effectiveness of the theoretical results. - Highlights: Pinning control problem of complex networks via intermittent control is investigated. The traditional assumptions on control width and time delays are removed. A scheme deciding what nodes should be chosen as pinned candidates is proposed. A scheme deciding how many nodes are needed to be pinned is provided.

  6. Evaluation of PWR and BWR pin cell benchmark results

    Energy Technology Data Exchange (ETDEWEB)

    Pilgroms, B.J.; Gruppelaar, H.; Janssen, A.J. (Netherlands Energy Research Foundation (ECN), Petten (Netherlands)); Hoogenboom, J.E.; Leege, P.F.A. de (Interuniversitair Reactor Inst., Delft (Netherlands)); Voet, J. van der (Gemeenschappelijke Kernenergiecentrale Nederland NV, Dodewaard (Netherlands)); Verhagen, F.C.M. (Keuring van Electrotechnische Materialen NV, Arnhem (Netherlands))

    1991-12-01

    Benchmark results of the Dutch PINK working group on the PWR and BWR pin cell calculational benchmark as defined by EPRI are presented and evaluated. The observed discrepancies are problem dependent: a part of the results is satisfactory, some other results require further analysis. A brief overview is given of the different code packages used in this analysis. (author). 14 refs.; 9 figs.; 30 tabs.

  7. Axial migratin of cesium in LMFBR fuel pins

    International Nuclear Information System (INIS)

    Karnesky, R.A.; Bridges, A.E.; Jost, J.W.

    1981-11-01

    A correlated model for quantitatively predicting the behavior of cesium in LMFBR fuel pins has been developed. This correlation was shown to be in good agreement with experimental data. It has been used to predict the behavior of cesium in the FFTF driver fuel and as the result of this analysis it has been shown that the accumulation of cesium in the insulator pellets at the ends of the fuel column will not be life limiting

  8. Anticipating WPS PIN Vulnerability to Secure Wireless Network

    Directory of Open Access Journals (Sweden)

    Indra Dwi Rianto

    2013-12-01

    Full Text Available WiFi Protected Setup (WPS is a standardized function supported by numerous vendors of wireless routers and access point to help set up connection to a wireless local area network. It is designed to simplify the set up and generally enabled by default. Due to design flaw, the WPS or QSS PIN is susceptible to a brute forceattack. In this paper, we test the security vulnerability occurred, evaluate the performance and give recommendations to anticipate the attack.

  9. X-ray measurement with Pin type semiconductor detectors

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1999-01-01

    Here are presented the experimental results of the applications of Pin type radiation detectors developed in a National Institute of Nuclear Research (ININ) project, in the measurement of low energy gamma and X-rays. The applications were oriented mainly toward the Medical Physics area. It is planned other applications which are in process of implementation inside the National Institute of Nuclear Research in Mexico. (Author)

  10. Pinning by oxygen vacancies in high-Tc superconductors

    International Nuclear Information System (INIS)

    Chudnovsky, E.M.

    1990-01-01

    It is shown that recent data of Murray et al. on spatial correlations in flux lattices of Bi-Sr-Ca-Cu-O (BSCCO) may be explained if one assumes that 1% of oxygen atoms in CuO 2 layers are missing. This estimate, being in remarkable agreement with that deduced by Kes and van der Beek from ac-susceptibility measurements, provides strong confidence that oxygen vacancies are the major source of pinning in BSCCO

  11. Pins and posters: paradigms for content publication on situated displays

    OpenAIRE

    José, Rui; Pinto, Helder; Siva, Bruno; Melro, Ana

    2013-01-01

    Public display systems are still far from being a communication medium that people can appropriate to serve diverse communication goals. Moving towards open displays will require new publication paradigms that can overcome the challenges of meaningful engagement and enable users to fully understand and control the entire publication process. In this paper, we report on the study of two novel and complimentary communication paradigms for public displays inspired by the metaphors of pin badges ...

  12. Prevention of pin tract infection with titanium-copper alloys.

    Science.gov (United States)

    Shirai, Toshiharu; Tsuchiya, Hiroyuki; Shimizu, Tohru; Ohtani, Kaori; Zen, Yo; Tomita, Katsuro

    2009-10-01

    The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial. (c) 2009 Wiley Periodicals, Inc.

  13. Effective temperature in driven vortex lattices with random pinning

    International Nuclear Information System (INIS)

    Kolton, Alejandro B.; Dominguez, Daniel; Exartier, Raphael; Cugliandolo, Leticia F.; Groenbech-Jensen, N.

    2003-09-01

    We study numerically correlation and response functions in non-equilibrium driven vortex lattices with random pinning. From a generalized fluctuation-dissipation relation we calculate an effective transverse temperature in the fluid moving phase. We find that the effective temperature decreases with increasing driving force and becomes equal to the equilibrium melting temperature when the dynamic transverse freezing occurs. We also discuss how the effective temperature can be measured experimentally from a generalized Kubo formula. (author)

  14. FFTF metal fuel pin sodium bond quality verification

    International Nuclear Information System (INIS)

    Pitner, A.L.; Dittmer, J.O.

    1988-12-01

    The Fast Flux Test Facility (FFTF) Series III driver fuel design consists of U-10Zr fuel slugs contained in a ferritic alloy cladding. A liquid metal, sodium bond between the fuel and cladding is required to prevent unacceptable temperatures during operation. Excessive voiding or porosity in the sodium thermal bond could result in localized fuel melting during irradiation. It is therefore imperative that bond quality be verified during fabrication of these metal fuel pins prior to irradiation. This document discusses this verification

  15. The dynamics of plant plasma membrane proteins: PINs and beyond.

    Science.gov (United States)

    Luschnig, Christian; Vert, Grégory

    2014-08-01

    Plants are permanently situated in a fixed location and thus are well adapted to sense and respond to environmental stimuli and developmental cues. At the cellular level, several of these responses require delicate adjustments that affect the activity and steady-state levels of plasma membrane proteins. These adjustments involve both vesicular transport to the plasma membrane and protein internalization via endocytic sorting. A substantial part of our current knowledge of plant plasma membrane protein sorting is based on studies of PIN-FORMED (PIN) auxin transport proteins, which are found at distinct plasma membrane domains and have been implicated in directional efflux of the plant hormone auxin. Here, we discuss the mechanisms involved in establishing such polar protein distributions, focusing on PINs and other key plant plasma membrane proteins, and we highlight the pathways that allow for dynamic adjustments in protein distribution and turnover, which together constitute a versatile framework that underlies the remarkable capabilities of plants to adjust growth and development in their ever-changing environment. © 2014. Published by The Company of Biologists Ltd.

  16. Optimization of geometric parameters of heat exchange pipes pin finning

    Science.gov (United States)

    Akulov, K. A.; Golik, V. V.; Voronin, K. S.; Zakirzakov, A. G.

    2018-05-01

    The work is devoted to optimization of geometric parameters of the pin finning of heat-exchanging pipes. Pin fins were considered from the point of view of mechanics of a deformed solid body as overhang beams with a uniformly distributed load. It was found out under what geometric parameters of the nib (diameter and length); the stresses in it from the influence of the washer fluid will not exceed the yield strength of the material (aluminum). Optimal values of the geometric parameters of nibs were obtained for different velocities of the medium washed by them. As a flow medium, water and air were chosen, and the cross section of the nibs was round and square. Pin finning turned out to be more than 3 times more compact than circumferential finning, so its use makes it possible to increase the number of fins per meter of the heat-exchanging pipe. And it is well-known that this is the main method for increasing the heat transfer of a convective surface, giving them an indisputable advantage.

  17. Contact and Non-contact Measurements of Grinding Pins

    Directory of Open Access Journals (Sweden)

    Magdziak Marek

    2015-01-01

    Full Text Available The paper presents the results of contact and non-contact measurements of external profiles of selected grinding pins. The measurements were conducted in order to choose the appropriate measuring technique in the case of the considered measurement task. In the case of contact measurements the coordinate measuring machine ACCURA II was applied. The used coordinate measuring machine was equipped with the contact scanning probe VAST XT and the Calypso inspection software. Contact coordinate measurements were performed by using of different measurement strategies. The applied strategies included different scanning velocities and distances between measured points. Non-contact measurements were conducted by means of the tool presetter produced by the Mahr company. On the basis of gained results the guidelines concerning measurements of grinding pins were formulated. The measurements of analyzed grinding pins performed by means of the non-contact measuring system are characterized by higher reproducibility than the contact measurements. The low reproducibility of contact measurements may be connected with the inaccuracy of the selected coordinate measuring machine and the measuring probe, the measurement parameters and environmental conditions in the laboratory where the coordinate measuring machine is located. Moreover, the paper presents the possible application of results of conducted investigations. The results of non-contact measurements can be used in the simulation studies of grinding processes. The simulations may reduce the costs of machining processes.

  18. End-threaded intramedullary positive profile screw ended self-tapping pin (Admit pin) - A cost-effective novel implant for fixing canine long bone fractures.

    Science.gov (United States)

    Chanana, Mitin; Kumar, Adarsh; Tyagi, Som Prakash; Singla, Amit Kumar; Sharma, Arvind; Farooq, Uiase Bin

    2018-02-01

    The current study was undertaken to evaluate the clinical efficacy of end-threaded intramedullary pinning for management of various long bone fractures in canines. This study was conducted in two phases, managing 25 client-owned dogs presented with different fractures. The technique of application of end-threaded intramedullary pinning in long bone fractures was initially standardized in 6 clinical patients presented with long bone fractures. In this phase, end-threaded pins of different profiles, i.e., positive and negative, were used as the internal fixation technique. On the basis of results obtained from standardization phase, 19 client-owned dogs clinically presented with different fractures were implanted with end-threaded intramedullary positive profile screw ended self-tapping pin in the clinical application phase. The patients, allocated randomly in two groups, when evaluated postoperatively revealed slight pin migration in Group-I (negative profile), which resulted in disruption of callus site causing delayed union in one case and large callus formation in other two cases whereas no pin migration was observed in Group-II (positive profile). Other observations in Group-I was reduced muscle girth and delayed healing time as compared to Group-II. In clinical application, phase 21 st and 42 nd day post-operative radiographic follow-up revealed no pin migration in any of the cases, and there was no bone shortening or fragment collapse in end-threaded intramedullary positive profile screw ended self-tapping pin. The end-threaded intramedullary positive profile screw ended self-tapping pin used for fixation of long bone fractures in canines can resist pin migration, pin breakage, and all loads acting on the bone, i.e., compression, tension, bending, rotation, and shearing to an extent with no post-operative complications.

  19. Weak interactions at the SSC

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1986-03-01

    Prospects for the study of standard model weak interactions at the SSC are reviewed, with emphasis on the unique capability of the SSC to study the mechanism of electroweak symmetry breaking whether the associated new quanta are at the TeV scale or higher. Symmetry breaking by the minimal Higgs mechanism and by related strong interaction dynamical variants is summarized. A set of measurements is outlined that would calibrate the proton structure functions and the backgrounds to new physics. The ability to measure the three weak gauge boson vertex is found to complement LEP II, with measurements extending to larger Q 2 at a comparable statistical level in detectable decays. B factory physics is briefly reviewed as one example of a possible broad program of high statistics studies of sub-TeV scale phenomena. The largest section of the talk is devoted to the possible manifestations of symmetry breaking in the WW and ZZ production cross sections. Some new results are presented bearing on the ability to detect high mass WW and ZZ pairs. The principal conclusion is that although nonstandard model scenarios are typically more forgiving, the capability to study symmetry breaking in the standard model (and in related strong interaction dynamical variants) requires achieving the SSC design goals of √ s,L = 40Tev, 10 33 cm -2 sec -1 . 28 refs., 5 figs

  20. Probing supervoids with weak lensing

    Science.gov (United States)

    Higuchi, Yuichi; Inoue, Kaiki Taro

    2018-05-01

    The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot, is one of such features. If a large underdense region (supervoid) resides towards the Cold Spot, we would be able to detect a systematic shape distortion in the images of background source galaxies via weak lensing effect. In order to estimate the detectability of such signals, we used the data of N-body simulations to simulate full-sky ray-tracing of source galaxies. We searched for a most prominent underdense region using the simulated convergence maps smoothed at a scale of 20° and obtained tangential shears around it. The lensing signal expected in a concordant Λ cold dark matter model can be detected at a signal-to-noise ratio S/N ˜ 3. If a supervoid with a radius of ˜200 h-1 Mpc and a density contrast δ0 ˜ -0.3 at the centre resides at a redshift z ˜ 0.2, on-going and near-future weak gravitational lensing surveys would detect a lensing signal with S/N ≳ 4 without resorting to stacking. From the tangential shear profile, we can obtain a constraint on the projected mass distribution of the supervoid.

  1. Pin-wise Reactor Analysis Based on the Generalized Equivalence Theory

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hwan Yeal; Heo, Woong; Kim, Yong Hee [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    In this paper, a pin-wise reactor analysis is performed based on the generalized equivalence theory. From the conventional fuel assembly lattice calculations, pin-wise 2-group cross sections and pin DFs are generated. Based on the numerical results on a small PWR benchmark, it is observed that the pin-wise core analysis provide quite accurate prediction on the effective multiplication factor and the peak pin power error is bounded by about 3% in peripheral fuel assemblies facing the baffle-reflector. Also, it was found that relatively large pin power errors occur along the interface between clearly different fuel assemblies. It is expected that the GET-based pin-by-pin core calculation can be further developed as an advanced method for reactor analysis via improving the group constants and discontinuity factors. Recently, high-fidelity multi-dimensional analysis tools are gaining more attention because of their accurate prediction of local parameters for core design and safety assessment. In terms of accuracy, direct whole-core transport is quite promising. However, it is clear that it is still very costly in terms of the computing time and memory requirements. Another possible solution is the pin-by-pin core analysis in which only small fuel pins are homogenized and the 3-D core analysis is still performed using a low-order operator such as the diffusion theory. In this paper, a pin-by-pin core analysis is performed using the hybrid CMFD (HCMFD) method. Hybrid CMFD is a new global-local iteration method that has been developed for efficient parallel calculation of pinby-pin heterogeneous core analysis. For the HCMFD method, the one-node CMFD scheme is combined with a local two-node CMFD method in a non-linear way. Since the SPH method is iterative and SPH factors are not direction dependent, it is clear that SPH method takes more computing cost and cannot take into account the different heterogeneity and transport effects at each pin interface. Unlike the SPH

  2. Tribological Testing of Hemispherical Titanium Pin Lubricated by Novel Palm Oil: Evaluating Anti-Wear and Anti-Friction Properties

    Institute of Scientific and Technical Information of China (English)

    Norzahir Sapawe; Syahrullail Samion; Mohd Izhan Ibrahim; Md Razak Daud; Azli Yahya; Muhammad Farhan Hanafi

    2017-01-01

    In this study,the properties of hip implant material and lubricants were examined using a pin on disc apparatus,to compare the effect of metal-on-metal (MoM) contact with a bio-lubricant derived from palm oil.The behaviour of the lubricants was observed during the experiments,in which a hemispherical pin was loaded against a rotating disc with a groove.A titanium alloy was used to modify the hemispherical pin and disc.Before and after the experiments,the weight and surface roughness were analysed,to detect any degradation.The results were compared according to the different kinematic viscosities.The wear rates and level of friction with each lubricant were also examined.The lubricant with the highest viscosity had the lowest frictional value.Therefore,developing suitable lubricants has the potential to prolong the lifespan of prostheses or implants used in biomedical applications.The experiments collectively show that lubricants derived from palm oil could be used as efficient bio-lubricants in the future.

  3. HLM fuel pin bundle experiments in the CIRCE pool facility

    Energy Technology Data Exchange (ETDEWEB)

    Martelli, Daniele, E-mail: daniele.martelli@ing.unipi.it [University of Pisa, Department of Civil and Industrial Engineering, Pisa (Italy); Forgione, Nicola [University of Pisa, Department of Civil and Industrial Engineering, Pisa (Italy); Di Piazza, Ivan; Tarantino, Mariano [Italian National Agency for New Technologies, Energy and Sustainable Economic Development, C.R. ENEA Brasimone (Italy)

    2015-10-15

    Highlights: • The experimental results represent the first set of values for LBE pool facility. • Heat transfer is investigated for a 37-pin electrical bundle cooled by LBE. • Experimental data are presented together with a detailed error analysis. • Nu is computed as a function of the Pe and compared with correlations. • Experimental Nu is about 25% lower than Nu derived from correlations. - Abstract: Since Lead-cooled Fast Reactors (LFR) have been conceptualized in the frame of GEN IV International Forum (GIF), great interest has focused on the development and testing of new technologies related to HLM nuclear reactors. In this frame the Integral Circulation Experiment (ICE) test section has been installed into the CIRCE pool facility and suitable experiments have been carried out aiming to fully investigate the heat transfer phenomena in grid spaced fuel pin bundles providing experimental data in support of European fast reactor development. In particular, the fuel pin bundle simulator (FPS) cooled by lead bismuth eutectic (LBE), has been conceived with a thermal power of about 1 MW and a uniform linear power up to 25 kW/m, relevant values for a LFR. It consists of 37 fuel pins (electrically simulated) placed on a hexagonal lattice with a pitch to diameter ratio of 1.8. The FPS was deeply instrumented by several thermocouples. In particular, two sections of the FPS were instrumented in order to evaluate the heat transfer coefficient along the bundle as well as the cladding temperature in different ranks of sub-channels. Nusselt number in the central sub-channel was therefore calculated as a function of the Peclet number and the obtained results were compared to Nusselt numbers obtained from convective heat transfer correlations available in literature on Heavy Liquid Metals (HLM). Results reported in the present work, represent the first set of experimental data concerning fuel pin bundle behaviour in a heavy liquid metal pool, both in forced and

  4. Vortex dynamics in supraconductors in the presence of anisotropic pinning

    International Nuclear Information System (INIS)

    Soroka, O.K.

    2004-01-01

    Vortex dynamics in two different classes of superconductors with anisotropic unidirected pinning sites was experimentally investigated by magnetoresistivity measurements: YBCO-films with unidirected twins and Nb-films deposited on faceted Al 2 O 3 substrate surfaces. For the interpretation of the experimental results a theoretical model based on the Fokker-Planck equation was used. It was proved by X-ray measurements that YBCO films prepared on (001) NdGaO 3 substrates exhibit only one twin orientation in contrast to YBCO films grown on (100) SrTiO 3 substrates. The magnetoresistivity measurements of the YBCO films with unidirected twin boundaries revealed the existence of two new magnetoresistivity components, which is a characteristic feature of a guided vortex motion: an odd longitudinal component with respect to the magnetic field sign reversal and an even transversal component. However, due to the small coherence length in YBCO and the higher density of point-like defects comparing to high-quality YBCO single crystals, the strength of the isotropic point pinning was comparable with the strength of the pinning produced by twins. This smeared out all e ects caused by the pinning anisotropy. The behaviour of the odd longitudinal component was found to be independent of the transport current direction with respect to the twin planes. The magnetoresistivity measurements of faceted Nb films demonstrated the appearance of an odd longitudinal and even transversal component of the magnetoresistivity. The temperature and magnetic field dependences of all relevant magnetoresistivity components were measured. The angles between the average vortex velocity vector and the transport current direction calculated from the experimental data for the different transport current orientations with respect to the facet ridges showed that the vortices moved indeed along the facet ridges. An anomalous Hall effect, i.e. a sign change of the odd transversal magnetoresistivity, has been

  5. Correlations between fuel pins irradiated in fast and thermal fluxes using the frump fuel pin modelling program

    International Nuclear Information System (INIS)

    Hayns, M.R.; Adam, J.

    1975-08-01

    There is no experimental facilities in which a fuel pin can be irradiated in a fast environment under well defined conditions of over power or flow run down. Consequently most of the infor mation which is being accumulated on the behaviour of fuel pins under severe conditions is obtained from either capsule or loop rigs in thermal reactors. It is the purpose of this paper to highlight the differences between the behaviour of fuel pins irradiated in a thermal flux and a fast flux. A typical set of conditions is taken from an overpower experiment in a thermal flux and the behaviour of the system is analysed using the fuel modelling program FRUMP. A second numerical experiment is then performed in which the same conditions prevail, except that a fast flux is assumed, the criterion for comparison being that the total power input to the system is the same in both cases. From the many possible correlations which result from such an exercise the fuel tempreature has been selected to highlight various important features of the two irradiations. It is demonstrated that the flux depression can cause differences in the pin behaviour, even to altering the order of events in a transient. For example fuel melting will occur at different times and at different positions in the fuel in the two cases. It is concluded that the techniques of fuel modelling, as typified in the program FRUMP can provide a very useful tool indeed for the analysis of such experiments and for guiding the establishment of the appropriate correlations for the extrapolation to the fast flux case. (author)

  6. X-ray measurement with Pin type semiconductor detectors; Medicion de rayos X con detectores de semiconductor tipo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, Departamento de Electronica, C.P. 52045 Salazar, Estado de Mexico (Mexico)

    2000-07-01

    Here are presented the experimental results of the applications of Pin type radiation detectors developed in a National Institute of Nuclear Research (ININ) project, in the measurement of low energy gamma and X-rays. The applications were oriented mainly toward the Medical Physics area. It is planned other applications which are in process of implementation inside the National Institute of Nuclear Research in Mexico. (Author)

  7. French approach in fuel pin modelling for fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Pascard, R [CEA-Centre de Fontenay-aux-Roses, Fontenay-aux-Roses (France)

    1979-12-01

    The purpose of this paper is to present the general philosophy on the problem of fuel modelling now prevailing in France after a twelve years period of tremendously increasing knowledge on fuel behavior. When the Rapsodie fuel pin was designed in 1962 , little was known about the behavior of a mixed oxide fuel pin under fast flux ; but a large body of knowledge on UO{sub 2} behavior in thermal reactor was available together with some sparse irradiation results on (U Pu)O{sub 2} in French experimental reactors. The performances assigned to the pin were then rather modest in rating (400 w/cm) and in burnup (30,000 MWd/t). The AISI 316 steel in solution annealed state was chosen as cladding material. The clad itself was supposed to deform by thermal creep due to fission gas pressure (100% release), and was affected consequently by a strain limit criteria. The importance of clad temperature ({approx}650 deg.) was considered only in connection with thermal creep, the possibility of a chemical reaction between mixed oxide and clad being at that time hardly suspected. Rapsodie had only been at full power for a few months when appeared the evidence of stainless steel swelling under a fast neutrons flux. This swelling was observed on Rapsodie pins as soon as they experienced sufficient neutrons dose, roughly one year later. This entirely new problem came immediately in the front stage (and is still of major importance today), and was at the origin of the change from the Rapsodie to the Fortissimo core in order to accelerate materials testing versus void swelling by multiplying the flux by a factor two. Even with unforeseen swelling, the design of the Rapsodie and later on Fortissimo pin, allowed not only to reach the goal burnup, but to increase it steadily to roughly 100,000 MWd/t. Since then, the French approach in fuel pin design has still retained something of its original simplicity, and technological efficiency, attitude which is justified by the following

  8. Establishing the need for an engineering standard for agricultural hitch pins.

    Science.gov (United States)

    Deboy, G R; Knapp, W M; Field, W E; Krutz, G W; Corum, C L

    2012-04-01

    Documented incidents have occurred in which failure or unintentional disengagement of agricultural hitch pins has contributed to property damage and personal injury. An examination of current hitch pin use on a convenience sample of farm operations in Indiana revealed a variety of non-standard, worn and damaged, and inappropriately sized hitch pins in use. Informal interviews with the farm operators confirmed that hitch pin misuse, failure, or disengagement is a relatively widespread problem that remains largely unaddressed. On-site observations also suggested a low use of hitch pin retaining devices or safety chains. A review of prior research revealed that little attention has been given to this problem, and currently no documentation allows for an estimate of the frequency or severity of losses associated with hitch pin misuse, failure, or disengagement. No specific engineering standards were found that directly applied to the design, appropriate selection, or loading capacity of agricultural hitch pins. Major suppliers of replacement hitch pins currently provide little or no information on matching hitch pin size to intended applications, and most replacement hitch pins examined were of foreign origin, with the overwhelming majority imported from China or India. These replacement hitch pins provided no specifications other than diameter, length, and, in some cases, labeling that indicated that the pins had been "heat treated. " Testing of a sample of 11 commercially available replacement hitch pins found variation along the length of the pin shaft and between individual pins in surface hardness, a potential predictor of pin failure. Examination of 17 commercially available replacement pins also revealed a variety of identifiers used to describe pin composition and fabrication methods, e.g., "heat treated." None of the pins examined provided any specifications on loading capacity. It was therefore concluded that there is a need to develop an agricultural hitch

  9. Weak KAM for commuting Hamiltonians

    International Nuclear Information System (INIS)

    Zavidovique, M

    2010-01-01

    For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax–Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523–44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493–506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton–Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401–20)

  10. Postirradiation examinations of fuel pins from the GCFR F-1 series of mixed-oxide fuel pins at 5.5 at. % burnup

    International Nuclear Information System (INIS)

    Strain, R.V.; Johnson, C.E.

    1978-05-01

    Postirradiation examinations were performed on five fuel pins from the Gas-Cooled Fast-Breeder Reactor F-1 experiment irradiated in EBR-II to a peak burnup of approximately 5.5 at. %. These encapsulated fuel pins were irradiated at peak-power linear ratings from approximately 13 to 15 kW/ft and peak cladding inside diameter temperatures from approximately 625 to 760 0 C. The maximum diametral change that occurred during irradiation was 0.2% ΔD/D 0 . The maximum fuel-cladding chemical interaction depth was 2.6 mils in fuel pin G-1 and 1 mil or less in the other three pins examined destructively. Significant migration of the volatile fission products occurred axially to the fuel-blanket interfaces. Teh postirradiation examination data indicate that fuel melted at the inner surface of the annular fuel pellets in the two highest power rating fuel pins, but little axial movement of fuel occurred

  11. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    IAS Admin

    Quantum Field Theory created by Dirac and used by Fermi to describe weak ... of classical electrodynamics (from which the electric field and magnetic field can be obtained .... Universe. However, thanks to weak interactions, this can be done.

  12. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  13. Thermal and stress analyses in thermoelectric generator with tapered and rectangular pin configurations

    International Nuclear Information System (INIS)

    Yilbas, Bekir Sami; Akhtar, S.S.; Sahin, A.Z.

    2016-01-01

    Thermal stress developed in thermoelectric generators is critical for long service applications. High temperature gradients, due to a large temperature difference across the junctions, causes excessive stress levels developed in the device pins and electrodes at the interfaces. In the present study, a thermoelectric generator with horizontal pin configuration is considered and thermal stress analysis in the device is presented. Ceramic wafer is considered to resemble the high temperature plate and copper electrodes are introduced at the pin junctions to reduce the electrical resistance between the pins and the high and low temperature junction plates during the operation. Finite element code is used to simulate temperature and stress fields in the thermoelectric generator. In the simulations, convection and radiation losses from the thermoelectric pins are considered and bismuth telluride pin material with and without tapering is incorporated. It is found that von Mises stress attains high values at the interface between the hot and cold junctions and the copper electrodes. Thermal stress developed in tapered pin configuration attains lower values than that of rectangular pin cross-section. - Highlights: • Different cold junction temperatures improves thermoelectric generator performance. • von Mises stress remains high across copper electrodes and hot junction ceramics. • von Mises stress reduces along pin length towards cold junction. • Pin tapering lowers stress levels in thermoelectric generator.

  14. Excessive Cellular S-nitrosothiol Impairs Endocytosis of Auxin Efflux Transporter PIN2

    Directory of Open Access Journals (Sweden)

    Min Ni

    2017-11-01

    Full Text Available S-nitrosoglutathione reductase (GSNOR1 is the key enzyme that regulates cellular levels of S-nitrosylation across kingdoms. We have previously reported that loss of GSNOR1 resulted in impaired auxin signaling and compromised auxin transport in Arabidopsis, leading to the auxin-related morphological phenotypes. However, the molecular mechanism underpinning the compromised auxin transport in gsnor1-3 mutant is still unknown. Endocytosis of plasma-membrane (PM-localized efflux PIN proteins play critical roles in auxin transport. Therefore, we investigate whether loss of GSNOR1 function has any effects on the endocytosis of PIN-FORMED (PIN proteins. It was found that the endocytosis of either the endogenous PIN2 or the transgenically expressed PIN2-GFP was compromised in the root cells of gsnor1-3 seedlings relative to Col-0. The internalization of PM-associated PIN2 or PIN2-GFP into Brefeldin A (BFA bodies was significantly reduced in gsnor1-3 upon BFA treatment in a manner independent of de novo protein synthesis. In addition, the exogenously applied GSNO not only compromised the endocytosis of PIN2-GFP but also inhibited the root elongation in a concentration-dependent manner. Taken together, our results indicate that, besides the reduced PIN2 level, one or more compromised components in the endocytosis pathway could account for the reduced endocytosis of PIN2 in gsnor1-3.

  15. A three-dimensional pin-wise analysis for CEA ejection accident

    Energy Technology Data Exchange (ETDEWEB)

    Park, Guen-Tae; Park, Min-Ho; Park, Jin-Woo; Um, Kil-Sup; Choi, Tong-Soo [KEPCO NF, Daejeon (Korea, Republic of)

    2016-10-15

    The ejection of a control element assembly (CEA) with high reactivity worth causes the sudden insertion of reactivity into the core. Immediately after the CEA ejection, the nuclear power of the reactor dramatically increases in an exponential behavior until the doppler effect becomes important and turns the reactivity balance and power down to lower levels. The 3-D CEA ejection analysis methodology has been developed using the multi-dimensional code coupling system, CHASER, which couples three dimensional core neutron kinetics code ASTRA, subchannel analysis code THALES, and fuel performance analysis code FROST using message passing interface (MPI). This paper presents the pin-by-pin level analysis result with the 3-D CEA ejection analysis methodology using the CHASER. The pin-by-pin level analysis consists of DNBR, enthalpy and Pellet/Clad Mechanical Interaction (PCMI) analysis. All the evaluations are simulated for APR1400 plant loaded with PLUS7 fuel. In this paper, the pin-by-pin analysis using the multidimensional core transient code, CHASER, is presented with respect to enthalpy, DNBR and PCMI for APR1400 plant loaded with PLUS7 fuel. For the pin-by-pin enthalpy and DNBR analysis, the quarter core for HFP case or 15 - 20 assemblies around the most severe assembly for part powers or HZP cases are selected. And PCMI calculation is performed for all the rods in the whole core during a conservative time period. The pin-by-pin analysis results show that the regulatory guidelines of CEA ejection accident are satisfied.

  16. Relationships between head fixation pins for radiosurgery and the skull bone. Usefulness of a torque wrench

    International Nuclear Information System (INIS)

    Toyota, Shun; Seta, Hidetoshi; Muramatsu, Masatoshi; Kubo, Hitoshi; Takeda, Kan

    2003-01-01

    In stereotactic radiosurgery (SRS), fixation devices are secured to the patient's head with pins. However, there have been no standards for the use of such pins, which must be inserted with appropriate torque based on the surgeon's clinical judgment. Therefore, the pins may sometimes be tightened excessively and penetrate too deeply into the patient's skull. To improve safety in SRS, a torque wrench was used for pin insertion. The usefulness of the torque wrench was then evaluated by examining the relationships between the pins and skull bone and identifying differences according to the wrench used and the patient's bone thickness. CT images of patients who had previously undergone SRS were used to assess the relationships between the pins and skull bone. Differences according to the wrench used and pin insertion site were investigated. Compared with a standard wrench, use of the torque wrench decreased the insertion depth of pins in the skull bone. In terms of site, pins in the forehead were inserted more deeply. No differences related to the frontal sinus were observed. The use of a torque wrench improved safety during pin insertion for SRS procedures. (author)

  17. Finite Element Analysis of Laser Engineered Net Shape (LENS™) Tungsten Clad Squeeze Pins

    Science.gov (United States)

    Sakhuja, Amit; Brevick, Jerald R.

    2004-06-01

    In the aluminum high-pressure die-casting and indirect squeeze casting processes, local "squeeze" pins are often used to minimize internal solidification shrinkage in heavy casting sections. Squeeze pins frequently fail in service due to molten aluminum adhering to the H13 tool steel pins ("soldering"). A wide variety of coating materials and methods have been developed to minimize soldering on H13. However, these coatings are typically very thin, and experience has shown their performance on squeeze pins is highly variable. The LENS™ process was employed in this research to deposit a relatively thick tungsten cladding on squeeze pins. An advantage of this process was that the process parameters could be precisely controlled in order to produce a satisfactory cladding. Two fixtures were designed and constructed to enable the end and outer diameter (OD) of the squeeze pins to be clad. Analyses were performed on the clad pins to evaluate the microstructure and chemical composition of the tungsten cladding and the cladding-H13 substrate interface. A thermo-mechanical finite element analysis (FEA) was performed to assess the stress distribution as a function of cladding thickness on the pins during a typical casting thermal cycle. FEA results were validated via a physical test, where the clad squeeze pins were immersed into molten aluminum. Pins subjected to the test were evaluated for thermally induced cracking and resistance to soldering of the tungsten cladding.

  18. Finite element analysis of laser engineered net shape (LENSTM) tungsten clad squeeze pins

    International Nuclear Information System (INIS)

    Sakhuja, Amit; Brevick, Jerald R.

    2004-01-01

    In the aluminum high-pressure die-casting and indirect squeeze casting processes, local 'squeeze' pins are often used to minimize internal solidification shrinkage in heavy casting sections. Squeeze pins frequently fail in service due to molten aluminum adhering to the H13 tool steel pins ('soldering'). A wide variety of coating materials and methods have been developed to minimize soldering on H13. However, these coatings are typically very thin, and experience has shown their performance on squeeze pins is highly variable. The LENS TM process was employed in this research to deposit a relatively thick tungsten cladding on squeeze pins. An advantage of this process was that the process parameters could be precisely controlled in order to produce a satisfactory cladding. Two fixtures were designed and constructed to enable the end and outer diameter (OD) of the squeeze pins to be clad. Analyses were performed on the clad pins to evaluate the microstructure and chemical composition of the tungsten cladding and the cladding-H13 substrate interface. A thermo-mechanical finite element analysis (FEA) was performed to assess the stress distribution as a function of cladding thickness on the pins during a typical casting thermal cycle. FEA results were validated via a physical test, where the clad squeeze pins were immersed into molten aluminum. Pins subjected to the test were evaluated for thermally induced cracking and resistance to soldering of the tungsten cladding

  19. Liquid-metal pin-fin pressure drop by correlation in cross flow

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-01-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

  20. Displaced humeral lateral condyle fractures in children: should we bury the pins?

    Science.gov (United States)

    Das De, Soumen; Bae, Donald S; Waters, Peter M

    2012-09-01

    The purpose of this investigation was to determine if leaving Kirschner wires exposed is more cost-effective than burying them subcutaneously after open reduction and internal fixation (ORIF) of humeral lateral condyle fractures. A retrospective cohort study of all lateral condyle fractures treated over a 10-year period at a single institution was performed. Data on surgical technique, fracture healing, and complications were analyzed, as well as treatment costs. A decision analysis model was then constructed to compare the strategies of leaving the pins exposed versus buried. Finally, sensitivity analyses were performed, assessing cost-effectiveness when infection rates and costs of treating deep infections were varied. A total of 235 children with displaced fractures were treated with ORIF using Kirschner wires. Pins were left exposed in 41 cases (17.4%) and buried in 194 cases (82.6%); the age, sex, injury mechanisms, and fracture patterns were similar in both the groups. The median time to removal of implants was shorter with exposed versus buried pins (4 vs. 6 wk, Pfracture union or loss of reduction rates. The rate of superficial infection was higher with exposed pins (9.8% vs. 3.1%), but this was not statistically significant (P=0.076). There were no deep infections with exposed pins, whereas the rate of deep infection was 0.5% with buried pins (P=1.00). Buried pins were associated with additional complications, including symptomatic implants (7.2%); pins protruding through the skin (16%); internal pin migration necessitating additional surgery (1%); and skin necrosis (1%). The decision analysis revealed that leaving pins exposed resulted in an average cost savings of $3442 per patient. This strategy remained cost-effective even when infection rates with exposed pins approached 40%. Leaving the pins exposed after ORIF of lateral condyle fractures is safe and more cost-effective than burying the pins subcutaneously. Retrospective cohort study (level III).

  1. Weakly distributive modules. Applications to supplement submodules

    Indian Academy of Sciences (India)

    Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...

  2. Finite size and geometrical non-linear effects during crack pinning by heterogeneities: An analytical and experimental study

    Science.gov (United States)

    Vasoya, Manish; Unni, Aparna Beena; Leblond, Jean-Baptiste; Lazarus, Veronique; Ponson, Laurent

    2016-04-01

    Crack pinning by heterogeneities is a central toughening mechanism in the failure of brittle materials. So far, most analytical explorations of the crack front deformation arising from spatial variations of fracture properties have been restricted to weak toughness contrasts using first order approximation and to defects of small dimensions with respect to the sample size. In this work, we investigate the non-linear effects arising from larger toughness contrasts by extending the approximation to the second order, while taking into account the finite sample thickness. Our calculations predict the evolution of a planar crack lying on the mid-plane of a plate as a function of material parameters and loading conditions, especially in the case of a single infinitely elongated obstacle. Peeling experiments are presented which validate the approach and evidence that the second order term broadens its range of validity in terms of toughness contrast values. The work highlights the non-linear response of the crack front to strong defects and the central role played by the thickness of the specimen on the pinning process.

  3. Vortex lines in layered superconductors. II. Pinning and critical currents in high temperature superconductors

    Science.gov (United States)

    Manuel, P.

    1994-02-01

    In this article, a qualitative survey is given on the various phenomena which influence the critical current of high temperature superconductors. Critical current is defined as a property related to a non-zero electric field criterion, the level of which is fixed by experimental considerations, or efficiency requirements of applications. The presentation is restricted to extrinsic intragranular critical current, which depends in a complex way on the interplay between the characteristics of pinning centres and the properties of the vortex lattice. The discussion is focussed on the configuration {B} / / {c}, which contains the main elements of this problem. Differences of behaviour between Y(123) and BSCCO (Bi(2212) or Bi(2223)) are analysed in the context of their respective anisotropy factors. Possible regimes for pinning and creep are discussed in various temperature domains. From critical current results, a strong pinning regime is found to occur in BSCCO, whereas the pinning strength in Y(123) is still an open question. The thermal decrease of critical current allows a collective creep regime to appear in both materials, but at different temperature ranges. The disappearance of correlation effects near the irreversibility line results in a fall of the effective pinning energy. We show that in BSCCO, the effective pinning energy deduced from experimental results is not in agreement with pinning by randomly dispersed oxygen vacancies. Finally, we shortly describe the microstructures which could allow a more efficient pinning in future materials. On effectue une présentation qualitative des divers phénomènes qui contrôlent la valeur du courant critique dans les supraconducteurs à haute température. La notion de courant critique qui est utilisée est reliée à un critère de champ électrique non nul, fixé par des considérations expérimentales ou des exigences de rendement pour les applications. On se restreint au problème des courants critiques

  4. Simulation of Si P-i-N diodes for use in a positron emission tomography detector module

    International Nuclear Information System (INIS)

    Bailey, M.J.; University of Wollongong, NSW; Rosenfeld, A.; Lerch, M.; Taylor, G.; Heiser, G.

    2000-01-01

    Full text: Current Positron Emission Tomography (PET) systems consist of scintillation crystals optically coupled to photomultiplier tubes with associated electronics used to detect photons generated within the scintillator. The cost of photomultiplier tubes (PMTs) is considerable and is the major factor in the cost of PET systems. It has been suggested that Si P-i-N diodes can replace PMTs and provide Depth of Interaction (DOI) information for improved spatial resolution. Si P-i-N diodes of 25mm x 300μm and 3mm x 300μm cross sectional area were simulated using a 2D Monte Carlo program (PClD V5) from the UNSW photovoltics group. The diffusion lengths were varied from 0.5μm to 5μm and the charge collection characteristics of the diodes were observed. A 400nm monochromatic light source was used for the excitation as an approximation of the mean wavelength output from LSO crystal. The diodes were reverse biased with voltages 40V, 20V and 10V. The optimum diffusion length of up to 2μm and bias voltage of 40V were determined using the electric field, current density, carrier density and potential distribution results. These parameters will be used for the design of a device for optimal charge collection capabilities for the wavelengths encountered in PET applications. Further studies need to be conducted using spectra from LSO rather than a monochromatic source. The response of various Si P-i-N diodes to a monochromatic light source have been modeled in order to design a device for application in a PET detector module for DOI measurements. The charge collection within the first 2μm has been emphasized due to the strong absorption of photons from LSO near the surface.Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

  5. Weak links in high critical temperature superconductors

    Science.gov (United States)

    Tafuri, Francesco; Kirtley, John R.

    2005-11-01

    The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-TC superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence

  6. Weak links in high critical temperature superconductors

    International Nuclear Information System (INIS)

    Tafuri, Francesco; Kirtley, John R

    2005-01-01

    The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-T C superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence

  7. Magnetic relaxation, flux pinning and critical currents in superconductors

    International Nuclear Information System (INIS)

    Lichtenberger, K.S.

    1991-01-01

    A systematic study of the magnetic flux pinning properties in superconductors has been undertaken in an attempt to understand the differences between the flux creep behavior of classical superconductors and high-temperature superconductors (HTSC's). In HTSC's, the ratio of the effective flux pinning energy to the thermal energy, U 0 /kT, is much smaller than that of conventional superconductors, often approaching unity. This results in much larger creep rates in HTSC's than in conventional superconductors. It is necessary to find suitable models that describe flux creep in both classical superconductors and HTSC's. Results show that while these two classes of materials are quantitatively very different, a single pinning barrier mode adequately describes both, within the proper region of the H-T plane. The model is applied to a variety of superconductors and the results are contrasted. Although the H-T plane appears to be very different HTSC's than for conventional superconductors, qualitatively the same physics describes both. In HTSC's, near the upper critical field there exists a relatively wide region of superconducting fluctuations, followed successively by regions of thermodynamic reversibility, thermally assisted flux, flux creep, and finally rigid flux lattice where little, if any, motion of the flux lattice occurs. All of these regions are also present in conventional superconductors, but often much more difficult, especially the irreversibility transition and the fluctuation region. The central finding of the flux creep analysis is that the region of flux creep is defined as a band in the H-T plane in which 2 ≤ U 0 /kT ≤ 100, and that the flux creep model applies best within this band

  8. Progress on DEMO blanket attachment concept with keys and pins

    International Nuclear Information System (INIS)

    Vizvary, Zsolt; Iglesias, Daniel; Cooper, David; Crowe, Robert; Riccardo, Valeria

    2015-01-01

    Highlights: • DEMO blanket attachment system with keys and pins (without using bolts). • Blanket segments are preloaded by progressively designed springs. • Blanket back plate flexibility has a major impact on spring design. • Mechanical analysis of other components indicates no unresolvable issues. • Thermal analysis indicates acceptable temperatures for the support system. - Abstract: The blanket attachment has to cope with gravity, thermal and electromagnetic loads, also it has to be installed and serviced by remote handling. Pre-stressed components suffer from stress relaxation in irradiated environments such as DEMO. To circumvent this problem pre-stressed component should be either avoided or shielded, and where possible keys and pins should be used. This strategy has been proposed for the DEMO multi-module segments (MMS). The blanket segments are held by two tapered keys each, designed to allow thermal expansions while providing contact with the vacuum vessel and to resist the poloidal and radial moments the latter being dominant at 9.1 MNm inboard and 15 MNm outboard. On the top of the blanket segment there is a pin which provides vertical support. At the bottom another vertical support has to lock them in position after installation and manage the pre-load on the segments. The pre-load is required to deal with the electromagnetic loads during disruption. This is provided by a set of springs, which require shielding as they are preloaded. These are sized to cope with the force (3 MN inboard, 1.4 MN outboard) due to halo currents and the toroidal moment which can reverse. Calculations show that the flexibility of the blanket segment itself plays a significant role in defining the required support system. The blanket segment acts as a preloaded spring and it has to be part of the attachment design as well.

  9. Tips Under the Skin: A Simple Modification of Extension Block Pinning for Mallet Fractures.

    Science.gov (United States)

    Shin, Seung-Han; Lee, Yong-Suk; Kang, Jin-Woo; Kang, Wonwoo; Chung, Yang-Guk

    2018-03-01

    Pins exposed out of the skin after surgery for mallet fractures keep patients from washing their hands. The authors buried the tips of all pins under the skin while performing extension block pinning for 14 patients with mallet fractures. The patients were allowed to wash their hands 4 to 5 days postoperatively, without any dressing or splinting. The pins were removed at a mean of 8 weeks postoperatively. Solid union was achieved in all 14 fractures. No pull-out or subsidence of the pin was observed. No patient developed infection or other pin-related complications. Mean extension lag at final follow-up was 4°. [Orthopedics. 2018; 41(2):e299-e302.]. Copyright 2018, SLACK Incorporated.

  10. Physics evaluation for testino. of RAPS and TAPS fuel pins in CIRUS pressurised water loop

    International Nuclear Information System (INIS)

    John, Benjamin; Paul, O.P.K.

    1976-01-01

    Relevant calculations carried out to assess the reactivity effect, heat generation and other parameters for testing of RAPS and TAPS fuel pins in the Cirus pressurised water loop are summarised. The Cirus neutron flux level being low, in order to simulate the RAPS design heat rating of ∫ Kdtheta = 40 w/cm, the required plutonium enrichment in mixed plutonium uranium oxide fuel pin was worked out. The results showed that a PuO 2 enrichment of 1.5 wt percent would be necessary to meet the above requirement. The analysis for the TAPS pin indicated that the desired heat flux of 115w/cm 2 cannot be obtained in the Cirus loop with either a 7 pin cluster geometry, or with a single pin with the enrichment level as used in TAPS pin. Lattice code DUMLAC and the core simulation code AECLHEX were used for these studies. (author)

  11. Pin cell discontinuity factors in the transient 3-D discrete ordinates code TORT-TD - 237

    International Nuclear Information System (INIS)

    Seubert, A.

    2010-01-01

    This paper describes the application of generalized equivalence theory to the time-dependent 3-D discrete ordinates neutron transport code TORT-TD. The introduction of pin cell discontinuity factors into the discrete ordinates transport equation is described by assuming a linear dependence of the homogenized neutron angular flux within a pin cell which may be discontinuous at the interfaces to adjacent cells. The homogenized flux discontinuity at cell interfaces is expressed by pin cell discontinuity factors which in turn are determined from fuel assembly lattice calculations using HELIOS. Application of TORT-TD to the all rods in state of the PWR MOX/UO 2 Core Transient Benchmark with pin cell homogenized nuclear cross sections demonstrate the potential of pin cell discontinuity factors to reduce pin cell homogenization errors. (authors)

  12. Novel pinning control strategies for synchronisation of complex networks with nonlinear coupling dynamics

    International Nuclear Information System (INIS)

    Zhao-Bing, Liu; Hua-Guang, Zhang; Qiu-Ye, Sun

    2010-01-01

    This paper considers the global stability of controlling an uncertain complex network to a homogeneous trajectory of the uncoupled system by a local pinning control strategy. Several sufficient conditions are derived to guarantee the network synchronisation by investigating the relationship among pinning synchronisation, network topology, and coupling strength. Also, some fundamental and yet challenging problems in the pinning control of complex networks are discussed: (1) what nodes should be selected as pinned candidates? (2) How many nodes are needed to be pinned for a fixed coupling strength? Furthermore, an adaptive pinning control scheme is developed. In order to achieve synchronisation of an uncertain complex network, the adaptive tuning strategy of either the coupling strength or the control gain is utilised. As an illustrative example, a network with the Lorenz system as node self-dynamics is simulated to verify the efficacy of theoretical results. (general)

  13. A Universe without Weak Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad

    2006-04-07

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

  14. A Universe without Weak Interactions

    International Nuclear Information System (INIS)

    Harnik, R

    2006-01-01

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe

  15. A universe without weak interactions

    International Nuclear Information System (INIS)

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad

    2006-01-01

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''weakless universe'' is matched to our Universe by simultaneously adjusting standard model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the weakless universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multiparameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe

  16. Measurements of weak conversion lines

    International Nuclear Information System (INIS)

    Feoktistov, A.I.; Frantsev, Yu.E.

    1979-01-01

    Described is a new methods for measuring weak conversion lines with the help of the β spectrometer of the π √ 2 type which permits to increase the reliability of the results obtained. According to this method the measurements were carried out by short series with the storage of the information obtained on the punched tape. The spectrometer magnetic field was stabilized during the measuring of the conversion spectra with the help of three nmr recorders. Instead of the dependence of the pulse calculation rate on the magnetic field value was measured the dependence of the calculation rate on the value of the voltage applied between the source and the spectrometer chamber. A short description of the automatic set-up for measuring conversion lines according to the method proposed is given. The main set-up elements are the voltage multiplexer timer, printer, scaler and the pulse analyzer. With the help of the above methods obtained is the K 1035, 8 keV 182 Ta line. It is obtained as a result of the composition of 96 measurement series. Each measurement time constitutes 640 s 12 points are taken on the line

  17. Methodology for analyzing weak spectra

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Swainson, I.P.

    2000-02-01

    There is considerable interest in quantifying radionuclide transfer between environmental compartments. However, in many cases, it can be a challenge to detect concentrations of gamma-emitting radionuclides due to their low levels in environmental samples. As a result, it is valuable to develop analytical protocols to ensure consistent analysis of the areas under weak peaks. The current study has focused on testing how reproducibly peak areas and baselines can be determined using two analytical approaches. The first approach, which can be carried out using Maestro software, involves extracting net counts under a curve without fitting a functional form to the peak, whereas the second approach, which is used by most other peak fitting programs, determines net counts from spectra by fitting a Gaussian form to the data. It was found that the second approach produces more consistent peak area and baseline measurements, with the ability to de-convolute multiple, overlapping peaks. In addition, programs, such as Peak Fit, which can be used to fit a form to spectral data, often provide goodness of fit analyses, since the Gaussian form can be described using a characteristic equation against which peak data can be tested for their statistical significance. (author)

  18. Evaluation of integrally finned cladding for LMFBR fuel pins

    International Nuclear Information System (INIS)

    Cantley, D.A.; Sutherland, W.H.

    1975-01-01

    An integral fin design effectively reduces the coolant temperature gradients within an LMFBR subassembly by redistributing coolant flow so as to reduce the maximum cladding temperature and increase the duct wall temperature. The reduced cladding temperatures are offset by strain concentrations resulting from the fin geometry, so there is little net effect on predicted fuel pin performance. The increased duct wall temperatures, however, significantly reduce the duct design lifetime so that the final conclusion is that the integral fin design is inferior to the standard wire wrap design. This result, however, is dependent upon the material correlations used. Advanced alloys with improved irradiation properties could alter this conclusion

  19. Axial gap formation in P.W.R. fuel pins

    International Nuclear Information System (INIS)

    Roberts, G.; Jones, K.W.

    1978-07-01

    The potential mechanisms of axial gap formation in PWR fuel pins are examined analytically and also using evidence from post-irradiation examination (p.i.e.) investigation. It is concluded that fuel and cladding cannot remain in contact during densification and so the settling of of the fuel stack, which forms the gaps, must be prevented by such things as asperities in the cladding, fuel chips or tilted pellets. Examples from the p.i.e. examination programme are used to support this conclusion. (author)

  20. Strain scaling law for flux pinning in practical superconductors

    International Nuclear Information System (INIS)

    Ekin, J.W.

    1980-01-01

    Detailed experimental data are reported on the critical current and pinning force density of a number of different Nb 3 Sn conductors measured over an extensive range of magnetic fields and strain. Strain scaling in terms of the upper-critical field as scaling parameter is tested and a strain scaling relation formulated. This is compared with the data and its application to practical conductors described. The relation between this strain scaling law and the usual temperature scaling law is discussed and an empirical expression is obtained unifying the two. (U.K.)

  1. Onset of bulk pinning in BSCCO single crystals

    Science.gov (United States)

    van der Beek, C. J.; Indenbom, M. V.; Berseth, V.; Li, T. W.; Benoit, W.

    1996-11-01

    The long growth defects often found in Bi2Sr2CaCu2O8, “single” crystals effectively weaken the geometrical barrier and lower the field of first flux penetration. This means that the intrinsic (bulk) magnetic properties can be more easily accessed using magnetic measurements. Thus, the onset of strong bulk flux pinning in the sample bulk is determined to lie at T ≈ 40 K, indepedent of whether the field strength is above or below the field of the second peak in the magnetisation.

  2. Accurate analysis of pins irradiated in fast neutron reactors

    International Nuclear Information System (INIS)

    Regnaud, F.; Guichard, C.

    1976-01-01

    A device was developed for the chemical analysis of fissile materials in a whole fuel pin in order to determine U and Pu with an accuracy of about 0.1% in samples from 100 to 200g, irradiated at burn-up between 50 and 100.000MWd/t. This unit is provided with two shielded α hot cells. A dissolving device was developed which enables the dissolution of residues. Pu is determined by oxydation-reduction titration and U by the isotopic dilution method [fr

  3. FFTF fuel pin design procedure verification for transient operation

    International Nuclear Information System (INIS)

    Baars, R.E.

    1975-05-01

    The FFTF design procedures for evaluating fuel pin transient performance are briefly reviewed, and data where available are compared with design procedure predictions. Specifically, burst conditions derived from Fuel Cladding Transient Tester (FCTT) tests and from ANL loss-of-flow tests are compared with burst pressures computed using the design procedure upon which the cladding integrity limit was based. Failure times are predicted using the design procedure for evaluation of rapid reactivity insertion accidents, for five unterminated TREAT experiments in which well characterized fuel failures were deliberately incurred. (U.S.)

  4. Etat des lieux et perspectives du pin sylvestre en Wallonie

    OpenAIRE

    Thibaut, K.; Colson, Vincent; Lecomte, H.; Claessens, Hugues

    2007-01-01

    Si le pin sylvestre fut l’un des pionniers de la reforestation de nos contrées, l’engouement qu’il suscita au XIXe siècle semble aujourd’hui bien retombé. À travers l’analyse de la ressource disponible et d’une rapide enquête auprès des cantonnements de la DNF, l’article propose un état des lieux de cette essence et discute de ses perspectives dans le contexte actuel.

  5. Improving tribological and anti-bacterial properties of titanium external fixation pins through surface ceramic conversion.

    Science.gov (United States)

    Dong, Huan; Mukinay, Tatiana; Li, Maojun; Hood, Richard; Soo, Sein Leung; Cockshott, Simon; Sammons, Rachel; Li, Xiaoying

    2017-01-01

    In this study, an advanced ceramic conversion surface engineering technology has been applied for the first time to self-drilling Ti6Al4V external fixation pins to improve their performance in terms of biomechanical, bio-tribological and antibacterial properties. Systematic characterisation of the ceramic conversion treated Ti pins was carried out using Scanning electron microscope, X-ray diffraction, Glow-discharge optical emission spectroscopy, nano- and micro-indentation and scratching; the biomechanical and bio-tribological properties of the surface engineered Ti pins were evaluated by insertion into high density bone simulation material; and the antibacterial behaviour was assessed with Staphylococcus aureus NCTC 6571. The experimental results have demonstrated that the surfaces of Ti6Al4V external fixation pins were successfully converted into a TiO 2 rutile layer (~2 μm in thickness) supported by an oxygen hardened case (~15 μm in thickness) with very good bonding due to the in-situ conversion nature. The maximum insertion force and temperature were reduced from 192N and 31.2 °C when using the untreated pins to 182N and 26.1 °C when the ceramic conversion treated pins were tested. This is mainly due to the significantly increased hardness (more than three times) and the effectively enhanced wear resistance of the cutting edge of the self-drilling Ti pins following the ceramic conversion treatment. The antibacterial tests also revealed that there was a significantly reduced number of bacteria isolated from the ceramic conversion treated pins compared to the untreated pins of around 50 % after 20 h incubation, P < 0.01 (0.0024). The results reported are encouraging and could pave the way towards high-performance anti-bacterial titanium external fixation pins with reduced pin-track infection and pin loosing.

  6. The PIN1 family gene PvPIN1 is involved in auxin-dependent root emergence and tillering in switchgrass

    Directory of Open Access Journals (Sweden)

    Kaijie Xu

    2016-03-01

    Full Text Available Abstract Switchgrass (Panicum virgatum L.; family Poaceae is a warm-season C4 perennial grass. Tillering plays an important role in determining the morphology of aboveground parts and the final biomass yield of switchgrass. Auxin distribution in plants can affect a variety of important growth and developmental processes, including the regulation of shoot and root branching, plant resistance and biological yield. Auxin transport and gradients in plants are mediated by influx and efflux carriers. PvPIN1, a switchgrass PIN1-like gene that is involved in regulating polar transport, is a putative auxin efflux carrier. Neighbor-joining analysis using sequences deposited in NCBI databases showed that the PvPIN1gene belongs to the PIN1 family and is evolutionarily closer to the Oryza sativa japonica group. Tiller emergence and development was significantly promoted in plants subjected toPvPIN1 RNA interference (RNAi, which yielded a phenotype similar to that of wild-type plants treated with the auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid. A transgenic approach that inducedPvPIN1 gene overexpression or suppression altered tiller number and the shoot/root ratio. These data suggest that PvPIN1plays an important role in auxin-dependent adventitious root emergence and tillering.

  7. Investigation on Bond-Slip Behavior of Z-Pin Interfaces in X-Cor® Sandwich Structures Using Z-Pin Pull-Out Test

    Science.gov (United States)

    Shan, Hangying; Xiao, Jun; Chu, Qiyi

    2018-05-01

    The Z-Pin interfacial bond properties play an important role in the structural performance of X-Cor® sandwich structures. This paper presents an experimental investigation on bond-slip behavior of Z-Pin interfaces using Z-Pin pull-out test. Based on the experimental data the whole Z-Pin pull-out process consists of three stages: initial bonding, debonding and frictional sliding. Comparative experimental study on the influence of design parameters on bond-slip behavior of Z-Pin interfaces has also been performed. Numerical analyses were conducted with the ABAQUS finite element (FE) program to simulate the Z-Pins bond-slip response of the pull-out test. The Z-Pins interfacial bond-slip behavior was implemented using nonlinear spring elements characterized with the constitutive relation from experimental results. Numerical results were validated by comparison with experimental data, and reasonably good agreement was achieved between experimental and analytical pull-out force-slip curves.

  8. Near space radiation dosimetry in Australian outback using a balloon borne energy compensated PIN diode detector

    International Nuclear Information System (INIS)

    Mukherjee, Bhaskar; Wu, Xiaofeng; Maczka, Tomasz; Kwan, Trevor; Huang, Yijun; Mares, Vladimir

    2016-01-01

    This paper reports the near space ballooning experiment carried out at Australian outback town West Wyalong (33°51′S, 147°24′E) on 19 July 2015. Several dedicated electronic detectors including digital temperature and acceleration (vibration) sensors and an energy compensated PIN-diode gamma ray dosimeter were installed in a thermally insulated Styrofoam payload box. A 9 V Lithium-Polymer battery powered all the devices. The payload box was attached to a helium-filled latex weather balloon and set afloat. The balloon reached a peak burst altitude of 30 km and then soft-landed aided by a self-deploying parachute 66.2 km away form the launch site. The payload box was retrieved and data collected from the electronic sensors analysed. The integrated cosmic ray induced photon ambient dose equivalent recorded by the PIN diode detector was evaluated to be 0.36 ± 0.05 μSv. Furthermore, a high-altitude extended version of commercially available aviation dosimetry package EPCARD.Net (European Program package for the Calculation of Aviation Route Doses) was used to calculate the ambient dose equivalents during the balloon flight. The radiation environment originated from the secondary cosmic ray shower is composed of neutrons, protons, electrons, muons, pions and photons. The photon ambient dose equivalent estimated by the EPCARD.Net code found to be 0.47 ± 0.09 μSv. The important aspects of balloon based near-space radiation dosimetry are highlighted in this paper. - Highlights: • Near space ballooning experiment in Australian outback. • A PIN diode based gamma dosimeter was sent to an altitude of 30 km. • Ambient photon dose equivalent was evaluated as a function of altitude. • Results agreed well with the simulated data delivered by EPCARD.Net Code. • The atmospheric temperature and payload jerks were also assessed.

  9. Functionally different PIN proteins control auxin flux during bulbil development in Agave tequilana.

    Science.gov (United States)

    Abraham Juárez, María Jazmín; Hernández Cárdenas, Rocío; Santoyo Villa, José Natzul; O'Connor, Devin; Sluis, Aaron; Hake, Sarah; Ordaz-Ortiz, José; Terry, Leon; Simpson, June

    2015-07-01

    In Agave tequilana, reproductive failure or inadequate flower development stimulates the formation of vegetative bulbils at the bracteoles, ensuring survival in a hostile environment. Little is known about the signals that trigger this probably unique phenomenon in agave species. Here we report that auxin plays a central role in bulbil development and show that the localization of PIN1-related proteins is consistent with altered auxin transport during this process. Analysis of agave transcriptome data led to the identification of the A. tequilana orthologue of PIN1 (denoted AtqPIN1) and a second closely related gene from a distinct clade reported as 'Sister of PIN1' (denoted AtqSoPIN1). Quantitative real-time reverse transcription-PCR (RT-qPCR) analysis showed different patterns of expression for each gene during bulbil formation, and heterologous expression of the A. tequilana PIN1 and SoPIN1 genes in Arabidopsis thaliana confirmed functional differences between these genes. Although no free auxin was detected in induced pedicel samples, changes in the levels of auxin precursors were observed. Taken as a whole, the data support the model that AtqPIN1 and AtqSoPIN1 have co-ordinated but distinct functions in relation to auxin transport during the initial stages of bulbil formation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  10. Enquiry into the Topology of Plasma Membrane-Localized PIN Auxin Transport Components.

    Science.gov (United States)

    Nodzyński, Tomasz; Vanneste, Steffen; Zwiewka, Marta; Pernisová, Markéta; Hejátko, Jan; Friml, Jiří

    2016-11-07

    Auxin directs plant ontogenesis via differential accumulation within tissues depending largely on the activity of PIN proteins that mediate auxin efflux from cells and its directional cell-to-cell transport. Regardless of the developmental importance of PINs, the structure of these transporters is poorly characterized. Here, we present experimental data concerning protein topology of plasma membrane-localized PINs. Utilizing approaches based on pH-dependent quenching of fluorescent reporters combined with immunolocalization techniques, we mapped the membrane topology of PINs and further cross-validated our results using available topology modeling software. We delineated the topology of PIN1 with two transmembrane (TM) bundles of five α-helices linked by a large intracellular loop and a C-terminus positioned outside the cytoplasm. Using constraints derived from our experimental data, we also provide an updated position of helical regions generating a verisimilitude model of PIN1. Since the canonical long PINs show a high degree of conservation in TM domains and auxin transport capacity has been demonstrated for Arabidopsis representatives of this group, this empirically enhanced topological model of PIN1 will be an important starting point for further studies on PIN structure-function relationships. In addition, we have established protocols that can be used to probe the topology of other plasma membrane proteins in plants. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Research on Pin Tumbler Locks and the Characteristics of Surface Traces Formed by Unlocking Guns

    Science.gov (United States)

    Yi, Gao; Yifeng, Jin; Yanping, Bai; Hongcheng, Mei; Zhen, Xu

    2018-02-01

    In this paper, taking the structure of the pin tumbler locks and the principle of opening and closing locks as breakthrough point, we have studied the machining traces of pin tumbler components and trace characters of pin surface during normal operating. At the same time, taking the unlocking gun as an example, the paper analyzes the unlocking technology and the formation of traces, and summarizes the changing rules of the surface traces of elastic bead locks by comparing the positions and the characteristics of the traces, which provides technical support for the future study of traces of pin tumbler locks.

  12. Nominal power density analysis of thermoelectric pins with non-constant cross sections

    International Nuclear Information System (INIS)

    Shi, Yaoguang; Mei, Deqing; Yao, Zhehe; Wang, Yancheng; Liu, Haiyan; Chen, Zichen

    2015-01-01

    Highlights: • Nominal power density of TEGs with non-constant cross sections pins is analyzed. • An analytical model of nominal power density (NPD) is developed. • Influences of shape parameter on NPD for different geometric pins are investigated. • Effects of dimensionless efficiency and the temperature ratio on NPD are examined. - Abstract: The investigation of the geometric structure of TEG (thermoelectric generator) pins is essential, as their geometry determines the performance of devices. In this study, nominal power density (NPD) is used to find a better geometric structure of thermoelectric pins of TEGs, since a comparison of maximum dimensionless efficiencies for different geometric pins cannot be used to identify the optimum geometry. The influence of shape parameter on NPD for TEG pins in linear, quadratic and exponential cross-sectional functions is studied. The NPD decreases when the shape parameter increases for different geometric pins, while the maximum values of NPD are the same. Then, the effects of dimensionless efficiency and the temperature ratio on the NPD are analyzed. The NPD decreases with the increase in dimensionless efficiency and temperature ratio. Pins with linear variation in cross section have the highest NPD among the three geometries of pins evaluated

  13. Peptidyl Prolyl Isomerase PIN1 Directly Binds to and Stabilizes Hypoxia-Inducible Factor-1α.

    Directory of Open Access Journals (Sweden)

    Hyeong-Jun Han

    Full Text Available Peptidyl prolyl isomerase (PIN1 regulates the functional activity of a subset of phosphoproteins through binding to phosphorylated Ser/Thr-Pro motifs and subsequently isomerization of the phosphorylated bonds. Interestingly, PIN1 is overexpressed in many types of malignancies including breast, prostate, lung and colon cancers. However, its oncogenic functions have not been fully elucidated. Here, we report that PIN1 directly interacts with hypoxia-inducible factor (HIF-1α in human colon cancer (HCT116 cells. PIN1 binding to HIF-1α occurred in a phosphorylation-dependent manner. We also found that PIN1 interacted with HIF-1α at both exogenous and endogenous levels. Notably, PIN1 binding stabilized the HIF-1α protein, given that their levels were significantly increased under hypoxic conditions. The stabilization of HIF-1α resulted in increased transcriptional activity, consequently upregulating expression of vascular endothelial growth factor, a major contributor to angiogenesis. Silencing of PIN1 or pharmacologic inhibition of its activity abrogated the angiogenesis. By utilizing a bioluminescence imaging technique, we were able to demonstrate that PIN1 inhibition dramatically reduced the tumor volume in a subcutaneous mouse xenograft model and angiogenesis as well as hypoxia-induced transcriptional activity of HIF-1α. These results suggest that PIN1 interacting with HIF-1α is a potential cancer chemopreventive and therapeutic target.

  14. Study of fuel bundle geometry on inter subchannel flow in a 19 pin wire wrapped bundle

    International Nuclear Information System (INIS)

    Naveen Raj, M.; Velusamy, D.K.

    2015-01-01

    In typical sodium cooled fast reactor (SFR) fuel pin bundle, gap between the pins is maintained by helically wound wire wrap around each pin. The presence of wire induces large inter-subchannel transverse flow, eventually promoting mixing and heat transfer. The magnitude of the transverse flow is highly dependent on the various pin-bundle dimensions. Appropriate modeling of these transverse flows in subchannel codes is necessary to predict realistic temperature distribution in pin bundle. Hence, detailed parametric study of transverse flow on pin-bundle geometric parameters has been conducted. The parameters taken for the present study are pin diameter, wire diameter, helical wire pitch and edge gap. Towards this 3-D computational fluid dynamic analysis on a structured mesh of 19 pin bundle is carried out using k-epsilon turbulence model. Periodic oscillations along the primacy flow direction were found in subchannel transverse flow and peripheral pin clad temperatures with periodicity over one pitch length. Based on parametric studies, correlations for transverse flow in central subchannels are proposed. (author)

  15. Comparative analysis of different methods of modelling of most loaded fuel pin in transients

    International Nuclear Information System (INIS)

    Ovdiyenko, Y.; Khalimonchuk, V.; Ieremenko, M.

    2007-01-01

    Different methods of modeling of most loaded fuel pin are presented at the work. Calculation studies are performed on example of accident related to WWER-1000 cluster rod ejection with using of spatial kinetic code DYN3D that uses nodal method to calculate distribution of neutron flux in the core. Three methods of modeling of most loaded fuel pin are considered - flux reconstruction in fuel macrocell, pin-by-pin calculation by using of DYN3D/DERAB package and by introducing of additional 'hot channel'. Obtained results of performed studies could be used for development of calculation kinetic models during preparing of safety analysis report (Authors)

  16. A model of high-rate indentation of a cylindrical striking pin into a deformable body

    Science.gov (United States)

    Zalazinskaya, E. A.; Zalazinsky, A. G.

    2017-12-01

    Mathematical modeling of an impact and high-rate indentation to a significant depth of a flat-faced hard cylindrical striking pin into a massive deformable target body is carried out. With the application of the kinematic extreme theorem of the plasticity theory and the kinetic energy variation theorem, the phase trajectories of the striking pin are calculated, the initial velocity of the striking pin in the body, the limit values of the inlet duct length, and the depth of striking pin penetration into the target are determined.

  17. Homological properties of modules with finite weak injective and weak flat dimensions

    OpenAIRE

    Zhao, Tiwei

    2017-01-01

    In this paper, we define a class of relative derived functors in terms of left or right weak flat resolutions to compute the weak flat dimension of modules. Moreover, we investigate two classes of modules larger than that of weak injective and weak flat modules, study the existence of covers and preenvelopes, and give some applications.

  18. Tailoring the vortex pinning strength of YBCO thin films by systematic incorporation of hybrid artificial pinning centers

    International Nuclear Information System (INIS)

    Jha, Alok K; Matsumoto, Kaname; Horide, Tomoya; Saini, Shrikant; Mele, Paolo; Ichinose, Ataru; Yoshida, Yutaka; Awaji, Satoshi

    2015-01-01

    The effect of hybrid (columnar and spherical together) artificial pinning centers (APCs) on the vortex pinning properties of YBa 2 Cu 3 O 7−δ (YBCO) thin films is investigated in detail on the basis of variation of critical current density (J C ) with applied magnetic field and also with the orientation of the applied magnetic field at 65 K and 77 K. Premixed YBCO + BaSnO 3 composite targets are used for the deposition of the YBCO films which consist of self-assembled BaSnO 3 nanocolumns (1D APCs); on the other hand, for the deposition of the YBCO films with hybrid APCs (BaSnO 3 nanocolumns together with Y 2 O 3 nanoparticles), the surface of the premixed YBCO + BaSnO 3 composite targets are modified by putting a thin Y 2 O 3 sectored piece on the premixed YBCO + BaSnO 3 composite targets by means of silver paste. F pmax value increases systematically with incorporation of 1D and 1D and 3D APCs and it also shifts towards higher applied magnetic fields. Films with 1D APCs exhibit a strong J C peak at Θ = 0° (H//c-axis) whereas films consisting of hybrid APCs exhibit enhanced J C at all the investigated angular regimes. A possible mechanism of vortex pinning in samples with hybrid APCs is also discussed suggesting the role of 1D and 3D APCs. (paper)

  19. International experience with the bundle behavior of fuel elements of sodium cooled reactors; derivation of a figure of merit for the judgement of fuel pin bundle parameters with respect to abrasion due to thermoelastic pin-pin interaction

    International Nuclear Information System (INIS)

    Toebbe, H.

    1987-10-01

    The report describes the status of experience with respect to the abrasion behavior of bundles in standard fuel elements and test elements with wire or grid spacing in the reactors Rapsodie fortissimo, Phenix, DFR, PFR, EBR-II, FFTF, JOYO and KNK II. With the help of simple considerations concerning thermoelastic pin-pin interactions a figure of merit is deduced from the different bundle parameters, which allows a comparative judgement of the parameters of different bundle concepts [de

  20. Weak boson emission in hadron collider processes

    International Nuclear Information System (INIS)

    Baur, U.

    2007-01-01

    The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel

  1. Sensitive pre-amplifier to load for Pin diodes

    International Nuclear Information System (INIS)

    Jacobo V, R. Y.; Hernandez D, V.; Ramirez J, F. J.

    2013-10-01

    The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer

  2. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    International Nuclear Information System (INIS)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M.; Koeck, Franz A. M.; Nemanich, Robert J.

    2016-01-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco ® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  3. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Science.gov (United States)

    Hathwar, Raghuraj; Dutta, Maitreya; Koeck, Franz A. M.; Nemanich, Robert J.; Chowdhury, Srabanti; Goodnick, Stephen M.

    2016-06-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  4. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M. [Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-8806 (United States); Koeck, Franz A. M.; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-8806 (United States)

    2016-06-14

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco{sup ®} Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures.

  5. Alternatives for water basin spent fuel storage using pin storage

    International Nuclear Information System (INIS)

    Viebrock, J.M.; Carlson, R.W.

    1979-09-01

    The densest tolerable form for storing spent nuclear fuel is storage of only the fuel rods. This eliminates the space between the fuel rods and frees the hardware to be treated as non-fuel waste. The storage density can be as much as 1.07 MTU/ft 2 when racks are used that just satisfy the criticality and thermal limitations. One of the major advantages of pin storage is that it is compatible with existing racks; however, this reduces the storage density to 0.69 MTU/ft 2 . Even this is a substantial increase over the 0.39 MTU/ft 2 that is achievable with current high capacity stainless steel racks which have been selected as the bases for comparison. Disassembly requires extensive operation on the fuel assembly to remove the upper end fitting and to extract the fuel rods from the assembly skeleton. These operations will be performed with the aid of an elevator to raise the assembly where each fuel rod is grappled. Lowering the elevator will free the fuel rod for transfer to the storage canister. A storage savings of $1510 per MTU can be realized if the pin storage concept is incorporated at a new away-from-reactor facility. The storage cost ranges from $3340 to $7820 per MTU of fuel stored with the lower cost applying to storage at an existing away-from-reactor storage facility and the higher cost applying to at-reactor storage

  6. Pinning mode of integer quantum Hall Wigner crystal of skyrmions

    Science.gov (United States)

    Zhu, Han; Sambandamurthy, G.; Chen, Y. P.; Jiang, P.-H.; Engel, L. W.; Tsui, D. C.; Pfeiffer, L. N.; West, K. W.

    2009-03-01

    Just away from integer Landau level (LL) filling factors ν, the dilute quasi-particles/holes at the partially filled LL form an integer-quantum-Hall Wigner crystal, which exhibits microwave pinning mode resonances [1]. Due to electron-electron interaction, it was predicted that the elementary excitation around ν= 1 is not a single spin flip, but a larger-scale spin texture, known as a skyrmion [2]. We have compared the pinning mode resonances [1] of integer quantum Hall Wigner crystals formed in the partly filled LL just away from ν= 1 and ν= 2, in the presence of an in-plane magnetic field. As an in-plane field is applied, the peak frequencies of the resonances near ν= 1 increase, while the peak frequencies below ν= 2 show neligible dependence on in-plane field. We interpret this observation as due to a skyrmion crystal phase around ν= 1 and a single-hole Wigner crystal phase below ν= 2. The in-plane field increases the Zeeman gap and causes shrinking of the skyrmion size toward single spin flips. [1] Yong P. Chen et al., Phys. Rev. Lett. 91, 016801 (2003). [2] S. L. Sondhi et al., Phys. Rev. B 47, 16 419 (1993); L. Brey et al., Phys. Rev. Lett. 75, 2562 (1995).

  7. Hydrophobic pinning with copper nanowhiskers leads to bactericidal properties.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available The considerable morbidity associated with hospitalized patients and clinics in developed countries due to biofilm formation on biomedical implants and surgical instruments is a heavy economic burden. An alternative to chemically treated surfaces for bactericidal activity started emerging from micro/nanoscale topographical cues in the last decade. Here, we demonstrate a putative antibacterial surface using copper nanowhiskers deposited by molecular beam epitaxy. Furthermore, the control of biological response is based on hydrophobic pinning of water droplets in the Wenzel regime, causing mechanical injury and cell death. Scanning electron microscopy images revealed the details of the surface morphology and non-contact mode laser scanning of the surface revealed the microtopography-associated quantitative parameters. Introducing the bacterial culture over nanowhiskers produces mechanical injury to cells, leading to a reduction in cell density over time due to local pinning of culture medium to whisker surfaces. Extended culture to 72 hours to observe biofilm formation revealed biofilm inhibition with scattered microcolonies and significantly reduced biovolume on nanowhiskers. Therefore, surfaces patterned with copper nanowhiskers can serve as potential antibiofilm surfaces. The topography-based antibacterial surfaces introduce a novel prospect in developing mechanoresponsive nanobiomaterials to reduce the risk of medical device biofilm-associated infections, contrary to chemical leaching of copper as a traditional bactericidal agent.

  8. Testing of the KRI-developed Silicon PIN Radioxenon Detector

    International Nuclear Information System (INIS)

    Foxe, Michael P.; McIntyre, Justin I.

    2015-01-01

    Radioxenon detectors are used for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in a network of detectors throughout the world called the International Monitoring System (IMS). The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Provisional Technical Secretariat (PTS) has tasked Pacific Northwest National Laboratory (PNNL) with testing a V.G. Khlopin Radium Institute (KRI) and Lares Ltd-developed Silicon PIN detector for radioxenon detection. PNNL measured radioxenon with the silicon PIN detector and determined its potential compared to current plastic scintillator beta cells. While the PNNL tested Si detector experienced noise issues, a second detector was tested in Russia at Lares Ltd, which did not exhibit the noise issues. Without the noise issues, the Si detector produces much better energy resolution and isomer peak separation than a conventional plastic scintillator cell used in the SAUNA systems in the IMS. Under the assumption of 1 cm 3 of Xe in laboratory-like conditions, 24-hr count time (12-hr count time for the SAUNA), with the respective shielding the minimum detectable concentrations for the Si detector tested by Lares Ltd (and a conventional SAUNA system) were calculated to be: 131m Xe - 0.12 mBq/m 3 (0.12 mBq/m 3 ); 133 Xe - 0.18 mBq/m 3 (0.21 mBq/m 3 ); 133m Xe - 0.07 mBq/m 3 (0.15 mBq/m 3 ); 135 Xe - 0.45 mBq/m 3 (0.67 mBq/m 3 ). Detection limits, which are one of the important factors in choosing the best detection technique for radioxenon in field conditions, are significantly better than for SAUNA-like detection systems for 131m Xe and 133m Xe, but similar for 133 Xe and 135 Xe. Another important factor is the amount of ''memory effect'' or carry over signal from one radioxenon measurement to the subsequent sample. The memory effect is reduced by a factor of 10 in the Si PIN detector compared to the current plastic scintillator cells. There is potential for further reduction with the

  9. Thermal-Hydraulic Simulations of Single Pin and Assembly Sector for IVG- 1M Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Garner, P. [Argonne National Lab. (ANL), Argonne, IL (United States); Hanan, N. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-15

    Thermal-hydraulic simulations have been performed using computational fluid dynamics (CFD) for the highly-enriched uranium (HEU) design of the IVG.1M reactor at the Institute of Atomic Energy (IAE) at the National Nuclear Center (NNC) in the Republic of Kazakhstan. Steady-state simulations were performed for both types of fuel assembly (FA), i.e. the FA in rows 1 & 2 and the FA in row 3, as well as for single pins in those FA (600 mm and 800 mm pins). Both single pin calculations and bundle sectors have been simulated for the most conservative operating conditions corresponding to the 10 MW output power, which corresponds to a pin unit cell Reynolds number of only about 7500. Simulations were performed using the commercial code STAR-CCM+ for the actual twisted pin geometry as well as a straight-pin approximation. Various Reynolds-Averaged Navier-Stokes (RANS) turbulence models gave different results, and so some validation runs with a higher-fidelity Large Eddy Simulation (LES) code were performed given the lack of experimental data. These singled out the Realizable Two-Layer k-ε as the most accurate turbulence model for estimating surface temperature. Single-pin results for the twisted case, based on the average flow rate per pin and peak pin power, were conservative for peak clad surface temperature compared to the bundle results. Also the straight-pin calculations were conservative as compared to the twisted pin simulations, as expected, but the single-pin straight case was not always conservative with regard to the straight-pin bundle. This was due to the straight-pin temperature distribution being strongly influenced by the pin orientation, particularly near the outer boundary. The straight-pin case also predicted the peak temperature to be in a different location than the twisted-pin case. This is a limitation of the straight-pin approach. The peak temperature pin was in a different location from the peak power pin in every case simulated, and occurred at an

  10. Classical field approach to quantum weak measurements.

    Science.gov (United States)

    Dressel, Justin; Bliokh, Konstantin Y; Nori, Franco

    2014-03-21

    By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.

  11. Experimental Qualification of the Sleeved Pin Multilink Attachment for Divertor PFC's

    International Nuclear Information System (INIS)

    Poutanen, J.; McCallum, A.; Turner, A.; Merola, M.

    2006-01-01

    The latest design for connecting the limited life ITER divertor plasma facing components (PFC's) to the reusable cassette body is the so called sleeved pin multilink attachment. The connection is made by expanding a 43 mm diameter hollow AlBr pin inside the fixation holes of components of the cassette body and PFC by a swaging process. The multilink is an easy, safe and fast assembly method, but the original dismantling method of drilling out the pin was found troublesome. Therefore, in the latest attachment design a thin sleeve is incorporated between the pin and the holes, which makes it possible to dismantle the joint by simply pulling out the pin and sleeve sequentially. Experimental qualification of the new sleeved design is now proceeding. The aim of the experimental qualification is to prove that the sleeved design meets the requirements of load carrying capability, clearance free connection, and easy and safe removal. Associated analytical studies were performed to develop and verify theoretical models and correlations for use in design. Results from the experimental qualification will provide reference information for developing tools for making and removing the connection. Theoretical finite element models in association with the results of earlier test campaigns with nonsleeved design were used to determine pin expansion parameters. The expansion parameters were verified with plate-pin tests measuring contact pressures produced by pin expansion. The plate-pin tests were also used to demonstrate the feasibility of pin removal and develop pin removal methodology. The mechanical capabilities of the connection design are being examined with test series of cyclic tensile loading plus articulation-induced loading of a single connection mock-up. Remaking properties of the attachment are being studied with multiple swaging and removing of the pin into the fixation holes. Finally the dismantling of the connection will be examined with full length pin extraction

  12. Improved Retrieval Technique of pin-wise composition for spent fuel recycling

    Energy Technology Data Exchange (ETDEWEB)

    Park, YunSeo; Kim, Myung Hyun [Kyung Hee University , Yongin (Korea, Republic of)

    2016-10-15

    New reutilization method which does not require fabrication processing was suggested and showed feasibility by Dr. Aung Tharn Daing. This new reutilization method is predict spent nuclear fuel pin composition, reconstruct new fuel assembly by spent nuclear pin, and directly reutilize in same PWR core. There are some limitation to predict spent nuclear fuel pin composition on his methodology such as spatial effect was not considered enough. This research suggests improving Dr. Aung Tharn Daing's retrieval technique of pin-wise composition. This new method classify fuel pin groups by its location effect in fuel assembly. Most of fuel pin composition along to burnup in fuel assembly is not highly dependent on location. However, compositions of few fuel pins where near water hole and corner of fuel assembly are quite different in same burnup. Required number of nuclide table is slightly increased from 3 to 6 for one fuel assembly with this new method. Despite of this little change, prediction of the pin-wise composition became more accurate. This new method guarantees two advantages than previous retrieving technique. First, accurate pin-wise isotope prediction is possible by considering location effect in a fuel assembly. Second, it requires much less nuclide tables than using full single assembly database. Retrieving technique of pin-wise composition can be applied on spent fuel management field useful. This technique can be used on direct use of spent fuel such as Dr. Aung Tharn Daing showed or applied on pin-wise waste management instead of conventional assembly-wise waste management.

  13. Clinical and histomorphometrical study on titanium dioxide-coated external fixation pins

    Directory of Open Access Journals (Sweden)

    Koseki H

    2013-02-01

    Full Text Available Hironobu Koseki,1 Tomohiko Asahara,1 Takayuki Shida,1 Itaru Yoda,1 Hidehiko Horiuchi,1 Koumei Baba,2 Makoto Osaki11Department of Orthopedic Surgery, Graduate School of Medicine, Nagasaki University, 2Industrial Technology Center of Nagasaki, Nagasaki, JapanBackground: Pin site infection is the most common and significant complication of external fixation. In this work, the efficacy of pins coated with titanium dioxide (TiO2 for inhibition of infection was compared with that of stainless steel control pins in an in vivo study.Methods: Pins contaminated with an identifiable Staphylococcus aureus strain were inserted into femoral bone in a rat model and exposed to ultraviolet A light for 30 minutes. On day 14, the animals were sacrificed and the bone and soft tissue around the pin were retrieved. The clinical findings and histological findings were evaluated in 60 samples.Results: Clinical signs of infection were present in 76.7% of untreated pins, but in only 36.7% of TiO2-coated pins. The histological bone infection score and planimetric rate of occupation for bacterial colonies and neutrophils in the TiO2-coated pin group were lower than those in the control group. The bone-implant contact ratio of the TiO2-coated pin group was significantly higher (71.4% than in the control pin group (58.2%. The TiO2 was successful in decreasing infection both clinically and histomorphometrically.Conclusion: The photocatalytic bactericidal effect of TiO2 is thought to be useful for inhibiting pin site infection after external fixation.Keywords: titanium dioxide, external fixation, bactericidal activity, Staphylococcus aureus

  14. Development of disassembly and pin chopping technology for FBR spent fuels

    International Nuclear Information System (INIS)

    Kobayashi, Tsuguyuki; Namba, Takashi; Kawabe, Yukinari; Washiya, Tadahiro

    2008-01-01

    Japan Atomic Power Company (JAPC) and Japan Atomic Energy Agency (JAEA) have been developing fuel disassembly and fuel pin chopping systems for a future Japanese commercial FBR. At first, the wrapper tube is cut by the slit-cut to pull it out, then the fuel pins are cut by the crop-cut at their end-plugs to separate them from the entrance nozzle. The pins are transferred to the magazine of the chopping machine. A series of tests were performed to develop this procedure. As the result of mechanical cutting tests, the CBN wheel was selected. The slit-cut tests were carried out to evaluated the cutting performance of the wheel. The wrapper tube is normally slit-cut in the circumferential direction. One CBN wheel could cut more than 5 fuel assemblies in this direction. The slit-cut in the axial direction is prepared as provision when the tube is difficult to put out. More work is needed to cut 5mm thick PNC-FMS plate in this direction without damaging the pins beneath it. As the result of the crop-cut tests of end-plugs made of ODS steel, the CBN wheel could cut the 61 pin bundle by two strokes. More work is needed to cut the 217 pin bundle. Fuel pin handling tests were performed to transfer them from the disassembly machine to the chopping machine. The Saucer tray was selected to receive the disassembled pins. All the pins were transferred and loaded into a magazine of the chopping machine. Fuel pin loading tests were conducted to optimize the magazine configuration to make the chopping length within 1.0±0.5 cm. In order to decrease the disturbance during chopping, the width of the magazine was adjusted to be 12 cm and installation of a height adjuster is favourable to control the free space above the pins. (author)

  15. Fabrication of uranium-plutonium mixed nitride fuel pins (88F-5A) for first irradiation test at JMTR

    International Nuclear Information System (INIS)

    Suzuki, Yasufumi; Iwai, Takashi; Arai, Yasuo; Sasayama, Tatsuo; Shiozawa, Ken-ichi; Ohmichi, Toshihiko; Handa, Muneo

    1990-07-01

    A couple of uranium-plutonium mixed nitride fuel pins was fabricated for the first irradiation tests at JMTR for the purpose of understanding the irradiation behavior and establishing the feasibility of nitride fuels as advanced FBR fuels. The one of the pins was fitted with thermocouples in order to observe the central fuel temperature. In this report, the fabrication procedure of the pins such as pin design, fuel pellet fabrication and characterizations, welding of fuel pins, and inspection of pins are described, together with the outline of the new TIG welder installed recently. (author)

  16. Instrumental systematics and weak gravitational lensing

    International Nuclear Information System (INIS)

    Mandelbaum, R.

    2015-01-01

    We present a pedagogical review of the weak gravitational lensing measurement process and its connection to major scientific questions such as dark matter and dark energy. Then we describe common ways of parametrizing systematic errors and understanding how they affect weak lensing measurements. Finally, we discuss several instrumental systematics and how they fit into this context, and conclude with some future perspective on how progress can be made in understanding the impact of instrumental systematics on weak lensing measurements

  17. Fixed points of occasionally weakly biased mappings

    OpenAIRE

    Y. Mahendra Singh, M. R. Singh

    2012-01-01

    Common fixed point results due to Pant et al. [Pant et al., Weak reciprocal continuity and fixed point theorems, Ann Univ Ferrara, 57(1), 181-190 (2011)] are extended to a class of non commuting operators called occasionally weakly biased pair[ N. Hussain, M. A. Khamsi A. Latif, Commonfixed points for JH-operators and occasionally weakly biased pairs under relaxed conditions, Nonlinear Analysis, 74, 2133-2140 (2011)]. We also provideillustrative examples to justify the improvements. Abstract....

  18. Robust weak measurements on finite samples

    International Nuclear Information System (INIS)

    Tollaksen, Jeff

    2007-01-01

    A new weak measurement procedure is introduced for finite samples which yields accurate weak values that are outside the range of eigenvalues and which do not require an exponentially rare ensemble. This procedure provides a unique advantage in the amplification of small nonrandom signals by minimizing uncertainties in determining the weak value and by minimizing sample size. This procedure can also extend the strength of the coupling between the system and measuring device to a new regime

  19. Sensitive pre-amplifier to load for Pin diodes; Pre-amplificador sensible a carga para diodos PIN

    Energy Technology Data Exchange (ETDEWEB)

    Jacobo V, R. Y.; Hernandez D, V. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Ramirez J, F. J., E-mail: yoshimarv@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer.

  20. Whole core pin-by-pin coupled neutronic-thermal-hydraulic steady state and transient calculations using COBAYA3 code

    International Nuclear Information System (INIS)

    Jimenez, J.; Herrero, J. J.; Cuervo, D.; Aragones, J. M.

    2010-10-01

    Nowadays coupled 3-dimensional neutron kinetics and thermal-hydraulic core calculations are performed by applying a radial average channel approach using a meshing of one quarter of assembly in the best case. This approach does not take into account the subchannels effects due to the averaging of the physical fields and the loose of heterogeneity in the thermal-hydraulic model. Therefore the models do not have enough resolution to predict those subchannels effects which are important for the fuel design safety margins, because it is in the local scale, where we can search the hottest pellet or the maximum heat flux. The Polytechnic University of Madrid advanced multi-scale neutron-kinetics and thermal-hydraulics methodologies being implemented in COBAYA3 include domain decomposition by alternate core dissections for the local 3-dimensional fine-mesh scale problems (pin cells/subchannels) and an analytical nodal diffusion solver for the coarse mesh scale coupled with the thermal-hydraulic using a model of one channel per assembly or per quarter of assembly. In this work, we address the domain decomposition by the alternate core dissections methodology applied to solve coupled 3-dimensional neutronic-thermal-hydraulic problems at the fine-mesh scale. The neutronic-thermal-hydraulic coupling at the cell-subchannel scale allows the treatment of the effects of the detailed thermal-hydraulic feedbacks on cross-sections, thus resulting in better estimates of the local safety margins at the pin level. (Author)