WorldWideScience

Sample records for beam-beam interactions

  1. Beam-Beam Interaction Studies at LHC

    CERN Document Server

    Schaumann, Michaela; Alemany Fernandez, R

    2011-01-01

    The beam-beam force is one of the most important limiting factors in the performance of a collider, mainly in the delivered luminosity. Therefore, it is essential to measure the effects in LHC. Moreover, adequate understanding of LHC beam-beam interaction is of crucial importance in the design phases of the LHC luminosity upgrade. Due to the complexity of this topic the work presented in this thesis concentrates on the beam-beam tune shift and orbit effects. The study of the Linear Coherent Beam-Beam Parameter at the LHC has been determined with head-on collisions with small number of bunches at injection energy (450 GeV). For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are as well ...

  2. Beam-beam interaction working group summary

    International Nuclear Information System (INIS)

    Siemann, R.H.

    1995-01-01

    The limit in hadron colliders is understood phenomenologically. The beam-beam interaction produces nonlinear resonances and makes the transverse tunes amplitude dependent. Tune spreads result from the latter, and as long as these tune spreads do not overlap low order resonances, the lifetime and performance is acceptable. Experience is that tenth and sometimes twelfth order resonances must be avoided, and the hadron collider limit corresponds roughly to the space available between resonances of that and lower order when operating near the coupling resonance. The beam-beam interaction in e + e - colliders is not understood well. This affects the performance of existing colliders and could lead to surprises in new ones. For example. a substantial amount of operator tuning is usually required to reach the performance limit given above, and this tuning has to be repeated after each major shutdown. The usual interpretation is that colliding beam performance is sensitive to small lattice errors, and these are being reduced during tuning. It is natural to ask what these errors are, how can a lattice be characterized to minimize tuning time, and what aspects of a lattice should receive particular attention when a new collider is being designed. The answers to this type of question are not known, and developing ideas for calculations, simulations and experiments that could illuminate the details of the beam-beam interaction was the primary working group activity

  3. Observations of the beam-beam interaction

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1985-11-01

    The observed complexity of the beam-beam interaction is the subject of this paper. The varied observations obtained from many storage rings happen to be sufficiently similar that a prescription can be formulated to describe the behavior of the luminosity as a function of beam current including the peak value. This prescription can be used to interpret various methods for improving the luminosity. Discussion of these improvement methods is accompanied with examples from actual practice. The consequences of reducing the vertical betatron function (one of the most used techniques) to near the value of the bunch length are reviewed. Finally, areas needing further experimental and calculational studies are pointed out as they are uncovered

  4. Studies of the beam-beam interaction for the LHC

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Furman, M.A.; Turner, W.C.

    1999-01-01

    The authors have used the beam-beam simulation code CBI to study the beam-beam interaction for the LHC. We find that for nominal LHC parameters, and assuming only one bunch per beam, there are no collective (coherent) beam-beam instabilities. We have investigated the effect of sweeping one of the beams around the other (a procedure that could be used as a diagnostic for head-on beam-beam collisions). We find that this does not cause any problems at the nominal current, though at higher currents there can be beam blow-up and collective beam motion. consequence of quadrupole collective effects

  5. Simulation study of the beam-beam interaction at SPEAR

    International Nuclear Information System (INIS)

    Tennyson, J.

    1980-01-01

    A two dimensional simulation study of the beam-beam interaction at SPEAR indicates that quantum fluctuations affecting the horizontal betatron oscillation play a critical role in the vertical beam blowup

  6. Studies of halo distributions under beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, T.; Irwin, J.; Siemann, R.H.

    1995-01-01

    The halo distribution due to the beam-beam interaction in circular electron-positron colliders is simulated with a program which uses a technique that saves a factor of hundreds to thousands of CPU time. The distribution and the interference between the beam-beam interaction and lattice nonlinearities has been investigated. The effects on the halo distribution due to radiation damping misalignment at the collision point, and chromatic effect are presented

  7. Beam-beam interaction in e+-e- storage rings

    International Nuclear Information System (INIS)

    Le Duff, J.

    1977-01-01

    Colliding beams in electron-positron storage rings are discussed with particular reference to the space charge forces occuring during beam-beam interactions and their effect on beam current and consequently machine performance (maximum luminosity). The first section deals with linear beam-beam effects and discussses linear tune shift; the second section considers non-linear beam-beam effects and the creation on non-linear resonances. The last section poses questions of the possibility of extrapolating present results to future machines and discusses optimization of storage ring performance. (B.D.)

  8. Beam-beam interactions in p-p storage rings

    International Nuclear Information System (INIS)

    Keil, E.

    1977-01-01

    There are two lectures: the first part of this paper (sections 2 to 5) deals with the theoretical aspects of the beam-beam interaction, and the second part (sections 6 to 8) describe the results of experiments in the ISR. Section 3 describes the strengths of the beam-beam interaction in terms of the linear tune shift ΔQ which has been calculated for several models. Because of the non-uniform density distribution in the beam the force results in a tune spread. This can be calculated by a perturbation method as explained in section 4. Section 5 discusses the simulation of the beam-beam interaction on a computer. Finally, section 6 reviews beam-beam phenomena observed in the CERN-ISR. These include the absence of observable beam-beam effects in unbunched beams, overlap knock-out resonances, collisions between a low-energy beam and a high-intensity stack, experiments with a nonlinear lens, and experiments with a high-β insertion. Section 7 contains a few concluding remarks. (Auth.)

  9. Beam-beam interactions in p-p storage rings

    CERN Document Server

    Keil, Eberhard

    1977-01-01

    There are two lectures. The first one (sections 2 to 5) deals with the theoretical aspects of the beam-beam interaction, and the second one (sections 6 to 8) describes the results of experiments in the ISR. Section 3 describes the strength of the beam-beam interaction in terms of the linear tune shift Delta Q which has been calculated for several models. Because of the non-uniform density distribution in the beam the force results in a tune spread. This can be calculated by a perturbation method as explained in section 4. Section 5 discusses the simulation of the beam-beam interaction on a computer. Finally, section 6 reviews beam-beam phenomena observed in the CERN-ISR. These include the absence of observable beam-beam effects in unbunched beams, overlap knock-out resonances, collisions between a low-energy beam and a high-intensity stack, experiments with a nonlinear lens, and experiments with a high- beta insertion. (20 refs).

  10. The renormalized theory of beam-beam interaction

    International Nuclear Information System (INIS)

    Chin, Yong Ho.

    1988-06-01

    A new approach to calculate analytically the particle distribution in the presence of beam-beam interaction and synchrotron radiation effects for an electron-positron colliding beam storage ring is presented. The method is based on correct calculation of the Green's function which includes the full effect of the beam-beam force on the distortion of particle orbits, borrowing the renormalization technique of quantum field therory. By this way, the theory is applicable to any level of beam-beam interaction, no matter whether chaos ensues in phase space or not. This paper is devoted mostly to verificaiton of the theory by comparison with the results of computer simulations. Fairly good agreements are obtained. 5 refs., 3 figs

  11. 6D beam-beam interaction step-by-step

    CERN Document Server

    Iadarola, Giovanni; Papaphilippou, Yannis; CERN. Geneva. ATS Department

    2017-01-01

    This document describes in detail the numerical method used in different simulation codes for the simulation of beam-beam interactions using the “Synchro Beam Mapping” approach, in order to correctly model the coupling introduced by beam-beam between the longitudinal and the transverse plane. The goal is to provide in a compact, complete and self-consistent manner the set of equations needed for the implementation in a numerical code. The effect of a “crossing angle” in an arbitrary “crossing plane” with respect to the assigned reference frame is taken into account with a suitable coordinate transformation. The employed description of the strong beam allows correctly accounting for the hour-glass effect as well as for linear coupling at the interaction point.

  12. Closed orbit distortion and the beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.; Chin, Y.H.; Eden, J. [Lawrence Berkeley Lab., CA (United States); Kozanecki, W. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)]|[Stanford Linear Accelerator Center, Menlo Park, CA (United States); Tennyson, J.; Ziemann, V. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1992-06-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for the SLAC/LBL/LLNL B factory, PEP-II. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the IP, provide distinct coordinate- or frequency-space signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed.

  13. Closed orbit distortion and the beam-beam interaction

    International Nuclear Information System (INIS)

    Furman, M.; Chin, Y.H.; Eden, J.; Kozanecki, W.; Tennyson, J.; Ziemann, V.

    1992-01-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for the SLAC/LBL/LLNL B factory, PEP-II. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the IP, provide distinct coordinate- or frequency-space signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed

  14. Observations and open questions in beam-beam interactions

    International Nuclear Information System (INIS)

    Sen, Tanaji

    2010-01-01

    The first of the hadron colliders, ISR, started operation in 1970. In the following years, the hadron colliders to follow were the SPS (started 1980), the Tevatron (started 1987 first as a fixed target machine), RHIC (started 2000) and most recently the LHC, which started in 2008. HERA was a hybrid that collided electrons and protons. All of these accelerators had or have their performance limited by the effects of the beam-beam interactions. That has also been true for the electron-positron colliders such as LEP, CESR, KEKB and PEPII. In this article I will discuss how the beam-beam limitations arose in some of these machines. The discussion will be focused on common themes that span the different colliders. I will mostly discuss the hadron colliders but sometimes discuss the lepton colliders where relevant. Only a handful of common accelerator physics topics are chosen here, the list is not meant to be exhaustive. A comparative review of beam-beam performance in the ISR, SPS and Tevatron (ca 1989) can be found in reference. Table 1 shows the relevant parameters of colliders (excluding the LHC), which have accelerated protons.

  15. Energy transparency and symmetries in the beam-beam interaction

    CERN Document Server

    Krishnagopal, S

    2000-01-01

    We have modified the beam-beam simulation code CBI to handle asymmetric beams and used it to look at energy transparency and symmetries in the beam-beam interaction. We find that even a small violation of energy transparency, or of the symmetry between the two beams, changes the character of the collective (coherent) motion; in particular, period-n oscillations are no longer seen. We speculate that the one-time observation of these oscillations at LEP, and the more ubiquitous observation of the flip-flop instability in colliders around the world, may be a consequence of breaking the symmetry between the electron and positron beams. We also apply this code to the asymmetric collider PEP-II, and find that for the nominal parameters of PEP-II, in particular, the nominal tune-shift parameter of xi /sub 0/=0.03, there are no collective beam-beam issues. Collective quadrupole motion sets in only at xi /sub 0/=0.06 and above, consistent with earlier observations for symmetric beams. (6 refs).

  16. Spin Depolarization due to Beam-Beam Interaction in NLC

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Kathleen A

    2001-01-04

    Calculations of spin depolarization effects due to the beam-beam interaction are presented for several NLC designs. The depolarization comes from both classical (Bargmann-Michel-Telegdi precession) and quantum (Sokolov-Ternov spin-flip) effects. It is anticipated that some physics experiments at future colliders will require a knowledge of the polarization to better than 0.5% precision. We compare the results of CAIN simulations with the analytic estimates of Yokoya and Chen for head-on collisions. We also study the effects of transverse offsets and beamstrahlung-induced energy spread.

  17. A Symplectic Beam-Beam Interaction with Energy Change

    International Nuclear Information System (INIS)

    Moshammer, Herbert

    2003-01-01

    The performance of many colliding storage rings is limited by the beam-beam interaction. A particle feels a nonlinear force produced by the encountering bunch at the collision. This beam-beam force acts mainly in the transverse directions so that the longitudinal effects have scarcely been studied, except for the cases of a collision with a crossing angle. Recently, however, high luminosity machines are being considered where the beams are focused extensively at the interaction point (IP) so that the beam sizes can vary significantly within the bunch length. Krishnagopal and Siemann have shown that they should not neglect the bunch length effect in this case. The transverse kick depends on the longitudinal position as well as on the transverse position. If they include this effect, however, from the action-reaction principle, they should expect, at the same time, an energy change which depends on the transverse coordinates. Such an effect is reasonably understood from the fact that the beam-beam force is partly due to the electric field, which can change the energy. The action-reaction principle comes from the symplecticity of the reaction: the electromagnetic influence on a particle is described by a Hamiltonian. The symplecticity is one of the most fundamental requirements when studying the beam dynamics. A nonsymplectic approximation can easily lead to unphysical results. In this paper, they propose a simple, approximately but symplectic mapping for the beam-beam interaction which includes the energy change as well as the bunch-length effect. In the next section, they propose the mapping in a Hamiltonian form, which directly assures its symplecticity. Then in section 3, they study the nature of the mapping by interpreting its consequences. The mapping itself is quite general and can be applied to any distribution function. They show in Section 4 how it appears when the distribution function is a Gaussian in transverse directions. The mapping is applied to the

  18. A map for the thick beam-beam interaction

    International Nuclear Information System (INIS)

    Irwin, J.; Chen, T.

    1995-01-01

    The authors give a closed-form expression for the thick beam-beam interaction for a small disruption parameter, as typical in electron-positron storage rings. The dependence on transverse angle and position of the particle trajectory as well as the longitudinal position of collision and the waist-modified shape of the beam distribution are included. Large incident angles, as are present for beam-halo particles or for large crossing-angle geometry, are accurately represented. The closed-form expression is well approximated by polynomials times the complex error function. Comparisons with multi-slice representations show even the first order terms are more accurate than a five slice representation, saving a factor of 5 in computation time

  19. Stability of the coherent quadrupole oscillations excited by the beam-beam interaction

    International Nuclear Information System (INIS)

    Kamiya, Y.; Chao, A.W.

    1983-10-01

    We study the coherent quadrupole motion in the presence of beam-beam interaction, using a linear approximation to the beam-beam force. The corresponding beam-beam limit is determined by evaluating the eigenvalues of a system of linear equations describing the coherent quadrupole motion. We find that the stability of the quadrupole motions imposes severe limits on the beam current, as is the case for the dipole instability. Preliminary results of this study have appeared elsewhere

  20. Limitations due to strong head-on beam-beam interactions (MD 1434)

    CERN Document Server

    Buffat, Xavier; Iadarola, Giovanni; Papadopoulou, Parthena Stefania; Papaphilippou, Yannis; Pellegrini, Dario; Pojer, Mirko; Crockford, Guy; Salvachua Ferrando, Belen Maria; Trad, Georges; Barranco Garcia, Javier; Pieloni, Tatiana; Tambasco, Claudia; CERN. Geneva. ATS Department

    2017-01-01

    The results of an experiment aiming at probing the limitations due to strong head on beam-beam interactions are reported. It is shown that the loss rates significantly increase when moving the working point up and down the diagonal, possibly due to effects of the 10th and/or 14th order resonances. Those limitations are tighter for bunches with larger beam-beam parameters, a maximum total beam-beam tune shift just below 0.02 could be reached.

  1. A new model for the collective beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, J.A.; Sobol, A.V. [New Mexico Univ., Albuquerque, NM (United States); Vogt, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-09-15

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the {pi} and {sigma} modes. The {pi} and {sigma} modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

  2. A new model for the collective beam-beam interaction

    International Nuclear Information System (INIS)

    Ellison, J.A.; Sobol, A.V.; Vogt, M.

    2006-09-01

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the π and σ modes. The π and σ modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

  3. Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

    Science.gov (United States)

    Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

    2009-12-01

    Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

  4. Exact suppression of depolarisation by beam-beam interaction in an electron ring

    International Nuclear Information System (INIS)

    Buon, J.

    1983-03-01

    It is shown that depolarisation due to beam-beam interaction can be exactly suppressed in an electron storage ring. The necessary ''spin matching'' conditions to be fulfilled are derived for a planar ring. They depend on the ring optics, assumed linear, but not on the features of the beam-beam force, like intensity and non-linearity. Extension to a ring equipped with 90 0 spin rotators is straightorward

  5. Coherent pair creation from beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, Pisin.

    1989-09-01

    It has recently been recognized that in future linear colliders, there is a finite probability that the beamstrahlung photons will turn into e + e - pairs induced by the same beam-beam field, and this would potentially cause background problems. In this paper, we first review the probability of such a coherent pair creation process. It is seen that the constraint on the beamstrahlung parameter, Υ, is tight of these coherent pairs to be totally suppressed. We then point out that there exists a minimum energy for the pair-created particles, which scales as ∼1/5Υ. When combining this condition with the deflection angle for the low-energy particles, the constraint on the allowable Υ value is much relaxed. Finally, we calculate the effective cross section for producing the weak bosons by the low-energy e + e - pairs. It is shown that these cross sections are substantial for Υ > 1. We suggest that this effect can help to autoscan the particle spectrum in the high energy frontier. 10 refs., 2 figs

  6. Modelling and implementation of the “6D” beam-beam interaction

    CERN Document Server

    Iadarola, Giovanni; Papaphilippou, Yannis

    2018-01-01

    These slides illustrate the numerical modelling of a beam-beam interaction using the “Synchro Beam Mapping” approach. The employed description of the strong beam allows correctly accounting for the hour-glass effect as well as for linear coupling at the interaction point. The implementation of the method within the SixTrack code is reviewed and tested.

  7. Dissipative effects in the beam-beam interaction of intersecting storage rings

    International Nuclear Information System (INIS)

    Ford, J.; Vivaldi, F.

    1982-01-01

    This proposal seeks continuing support for an ongoing research investigation of various dynamical instabilities which arise in high energy intersecting storage rings due to the beam-beam interaction. Although the dissipative effect of radiation in beam-beam machines is anticipated to be a dominant feature affecting stability in the dynamics of colliding beams of heavy particles, almost nothing is known regarding the stability problem in many-dimensional dissipative systems. The work proposed here will extend the earlier computations on weak instabilities in many-dimensional beam-beam models to include the effect of dissipation. The object of this research is to obtain conditions for global beam stability over long time scales as a function of the machine parameters

  8. Simulation of the beam halo from the beam-beam interaction in LEP

    International Nuclear Information System (INIS)

    Chen, T.; Irwin, J.; Siemann, R.

    1994-02-01

    The luminosity lifetimes of e + e - colliders are often dominated by the halo produced by the beam-beam interaction. They have developed a simulation technique to model this halo using the flux across boundaries in amplitude space to decrease the CPU time by a factor of one-hundred or more over 'brute force' tracking. It allows simulation of density distributions and halos corresponding to realistic lifetimes. Reference 1 shows the agreement with brute force tracking in a number of cases and the importance of beam-beam resonances in determining the density distribution of large amplitudes. this research is now directed towards comparisons with operating colliders and studies of the combined effects of lattice and beam-beam nonlinearities. LEP offers an ideal opportunity for both, and in this paper they are presenting the first results of LEP simulations

  9. Numerical Calculation of the Phase Space Density for the Strong-Strong Beam-Beam Interaction

    International Nuclear Information System (INIS)

    Sobol, A.; Ellison, J.A.

    2003-01-01

    We developed a parallel code to calculate the evolution of the 4D phase space density of two colliding beams, which are coupled via the collective strong-strong beam-beam interaction, in the absence of diffusion and damping, using the Perron-Frobenius (PF) operator technique

  10. Long-range beam-beam interactions in the Tevatron: Comparing simulation to tune shift data

    International Nuclear Information System (INIS)

    Saritepe, S.; Michelotti, L.; Peggs, S.

    1990-07-01

    Fermilab upgrade plans for the collider operation include a separation scheme in the Tevatron, in which protons and antiprotons are placed on separate helical orbits. The average separation distance between the closed orbits will be 5σ (σ of the proton bunch) except at the interaction regions, B0 and D0, where they collide head-on. The maximum beam-beam total tune shift in the Tevatron is approximately 0.024 (the workable tune space between 5th and 7th order resonances), which was reached in the 1988--1989 collider tun. Helical separation scheme allows us to increase the luminosity by reducing the total beam-beam tune shift. The number of bunches per beam will be 6 in the 1991 collider tun, to be increased to 36 in the following collider runs. To test the viability of this scenario, helical orbit studies are being conducted. The most recent studies concentrated on the injection of 36 proton bunches, procedures related to opening and closing of the helix, the feed-down circuits and the beam-beam interaction. In this paper, we present the results of the beam-beam interaction studies only. Our emphasis is on the tune shift measurements and the comparison to simulation. 4 refs., 9 figs., 2 tabs

  11. Simple computer model for the nonlinear beam--beam interaction in ISABELLE

    International Nuclear Information System (INIS)

    Herrera, J.C.; Month, M.; Peierls, R.F.

    1979-03-01

    The beam--beam interaction for two counter-rotating continuous proton beams crossing at an angle can be simulated by a 1-dimensional nonlinear force. The model is applicable to ISABELLE as well as to the ISR. Since the interaction length is short compared with the length of the beam orbit, the interaction region is taken to be a point. The problem is then treated as a mapping with the remainder of the system taken to be a rotation of phase given by the betatron tune of the storage ring. The evolution of the mean square amplitude of a given distribution of particles is shown for different beam--beam strengths. The effect of round-off error with resulting loss of accuracy for particle trajectories is discussed. 3 figures

  12. Review of linear collider beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.

    1989-01-01

    Three major effects from the interaction of e/sup +/e/sup /minus// beams---disruption, beamstrahlung, and electron-positron pair creation---are reviewed. For the disruption effects we discuss the luminosity enhancement factor, the maximum and rms disruption angles, and the ''kink instability''. All the results are obtained from computer simulations. Scaling laws for the numerical results and theoretical explanations of the computer acquired phenomena are offered wherever possible. For the beamstrahlung effects we concentrate only on the final electron energy spectrum resulting from multiple photon radiation process, and the deflection angle associated with low energy particles. For the effects from electron-positron pair creation, both coherent and incoherent processes of beamstrahlung pair creation are discussed. In addition to the estimation on total number of such pairs, we also look into the energy spectrum and the deflection angle. 17 refs., 23 figs., 1 tab.

  13. Review of linear collider beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, P.

    1989-01-01

    Three major effects from the interaction of e + e/sup /minus// beams---disruption, beamstrahlung, and electron-positron pair creation---are reviewed. For the disruption effects we discuss the luminosity enhancement factor, the maximum and rms disruption angles, and the ''kink instability''. All the results are obtained from computer simulations. Scaling laws for the numerical results and theoretical explanations of the computer acquired phenomena are offered wherever possible. For the beamstrahlung effects we concentrate only on the final electron energy spectrum resulting from multiple photon radiation process, and the deflection angle associated with low energy particles. For the effects from electron-positron pair creation, both coherent and incoherent processes of beamstrahlung pair creation are discussed. In addition to the estimation on total number of such pairs, we also look into the energy spectrum and the deflection angle. 17 refs., 23 figs., 1 tab

  14. Renormalization theory of beam-beam interaction in electron-positron colliders

    International Nuclear Information System (INIS)

    Chin, Y.H.

    1989-07-01

    This note is devoted to explaining the essence of the renormalization theory of beam-beam interaction for carrying out analytical calculations of equilibrium particle distributions in electron-positron colliding beam storage rings. Some new numerical examples are presented such as for betatron tune dependence of the rms beam size. The theory shows reasonably good agreements with the results of computer simulations. 5 refs., 6 figs

  15. Simulation of wire-compensation of long range beam beam interaction in high energy accelerators

    International Nuclear Information System (INIS)

    Dorda, U.; )

    2006-01-01

    Full text: We present weak-strong simulation results for the effect of long-range beam-beam (LRBB) interaction in LHC as well as for proposed wire compensation schemes or wire experiments, respectively. In particular, we discuss details of the simulation model, instability indicators, the effectiveness of compensation, the difference between nominal and PACMAN bunches for the LHC, beam experiments, and wire tolerances. The simulations are performed with the new code BBTrack. (author)

  16. Two Methods For Simulating the Strong-Strong Beam-Beam Interaction in Hadron Colliders

    International Nuclear Information System (INIS)

    Warnock, Robert L.

    2002-01-01

    We present and compare the method of weighted macro particle tracking and the Perron-Frobenius operator technique for simulating the time evolution of two beams coupled via the collective beam-beam interaction in 2-D and 4-D (transverse) phase space. The coherent dipole modes, with and without lattice nonlinearities and external excitation, are studied by means of the Vlasov-Poisson system

  17. Quadrupole modes in linearized beam-beam interaction in e+e- colliding rings

    International Nuclear Information System (INIS)

    Matsumoto, Shuji; Hirata, Kohji.

    1992-01-01

    The dynamic-beta model is extended, incorporating the synchrotron radiation effects. The model yields dynamic-emittance effect. The steady-state envelope matrix is explicitly obtained. Both equal-beam and flip-flop solutions are found. The stability of the steady-state solutions are investigated by numerical calculations. The model illustrates some characteristic features of the beam-beam interaction at e + e - colliding rings in spite of containing some qualitatively unrealistic points. (author)

  18. Beam-Beam Effects

    International Nuclear Information System (INIS)

    Herr, W; Pieloni, T

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities

  19. Beam-beam interaction and Pacman effects in the SSC with random nonlinear multipoles

    International Nuclear Information System (INIS)

    Goderre, G.P.; Ohnuma, S.

    1988-01-01

    In order to find the combined effects of beam-beam interaction (head-on and long-range) and random nonlinear multipoles in dipole magnets, transverse tunes and smears have been calculated as a function of oscillation amplitudes. Two types of particles, ''regular'' and ''Pacman,'' have been investigated using a modified version of tracking code TEAPOT. Regular particles experience beam-beam interactions in all four interaction regions (IR's), both head-on and long range, while pacman particles interact with bunches of the other beam in one medium-beta and one low-beta IR's only. The model for the beam-beam interaction is of weak-strong type and the strong beam is assumed to have a round Gaussian charge distribution. Furthermore, it is assumed that the vertical closed orbit deviation arising from the finite crossing angle of 70 μrad is perfectly compensated for regular particles. The same compensation applied to pacman particles creates a closed orbit distortion. Linear tunes are adjusted for regular particles to the design values but there are no nonlinear corrections except for chromaticity correcting sextupoles in two families. Results obtained in this study do not show any reduction of dynamic or linear aperture for pacman particles but some doubts exist regarding the validity of defining the linear aperture from the smear alone. Preliminary results are given for regular particles when (Δp/p) is modulated by the synchrotron oscillation. For these, fifty oscillations corresponding to 26,350 revolutions have been tracked. A very slow increase in the horizontal amplitude, /approximately/4 /times/ 10/sup /minus/4//oscillation (relative), is a possibility but this should be confirmed by trackings of larger number of revolutions. 11 refs., 18 figs., 2 tabs

  20. Effects of parasitic beam-beam interaction during the injection process at the PEP-II B Factory

    International Nuclear Information System (INIS)

    Chin, Y.H.

    1992-06-01

    This paper is concerned with beam-beam effects during the injection process at the proposed asymmetric SLAC/LBL/LLNL B-Factory, PEP-II. It is shown that the parasitic beam-beam interaction can lead to a significant blowup in the vertical size of the injected beam. Simulation results for the horizontal and the vertical injection schemes are presented, and their performances are studied

  1. Compensation of the Long-Range Beam-Beam Interaction in the LHC

    CERN Document Server

    AUTHOR|(CDS)2256057; De Conto, Jean-Marie

    In the LHC, protons collide in four interaction points in order to deliver luminosity to detectors located there. In the next machine upgrade, the High Luminosity LHC, the objective is to increase this luminosity by a factor five. By sharing the same vacuum pipes, the two counter rotating beams are interacting with a longitudinal offset with respect to the IP: this effect is called Long-Range Beam-Beam interaction. In order to compensate this effect, a device is currently studying in the LHC: the Beam-Beam Compensator Wire. It consists in a DC wire carrying a current and imitating the strong beam, in the weak-strong approximation. This thesis reports a study of this device. First, we show under which hypothesis the strong beam can be equivalent to a wire. Then, we characterise the magnetic field of this wire and its effect on the weak beam before presenting results of experiments we led in order to demonstrate the beneficial effect of this device.

  2. Beam-beam interaction and pacman effects in the SSC with momentum oscillation

    International Nuclear Information System (INIS)

    Mahale, N.K.; Ohnuma, S.

    1989-01-01

    In order to find the combined effects of beam-beam interaction (head-on and long-range) and random nonlinear multipoles in dipole magnets, the transverse oscillations of ''regular'' as well as ''pacman'' particles are traced for 256 synchrotron oscillation periods (corresponding to 135K revolutions) in the proposed SSC. Results obtained in this study do not show any obvious reduction of dynamic or linear apertures for pacman particles when compared with regular particles for (Δp/p) = 0. There are some indications of possible sudden or gradual increases in the oscillation amplitude, for pacman as well as regular particles, when the amplitude of momentum oscillation is as large as 3σ. 4 refs., 7 figs

  3. Symmetrization of the beam-beam interaction in an asymmetric collider

    International Nuclear Information System (INIS)

    Chin, Y.H.

    1990-07-01

    This paper studies the idea of symmetrizing both the lattice and the beams of an asymmetric collider, and discusses why this regime should be within the parametric reach of the design in order to credibly ensure its performance. Also examined is the effectiveness of a simple compensation method using the emittance as a free parameter and that it does not work in all cases. At present, when there are no existing asymmetric colliders, it seems prudent to design an asymmetric collider so as to be similar to a symmetric one (without relying on a particular theory of the asymmetric beam-beam interaction that has not passed tests of fidelity). Nevertheless, one must allow for the maximum possible flexibility and freedom in adjusting those parameters that affect luminosity. Such a parameter flexibility will be essential in tuning the collider to the highest luminosity

  4. Effect of a spectrometer magnet on the beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, M; Parzen, G

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors.

  5. Effect of a spectrometer magnet on the beam-beam interaction

    International Nuclear Information System (INIS)

    Cornacchia, M.; Parzen, G.

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors

  6. Status of the studies on collective effects involving beam-beam interactions at the HL-LHC

    CERN Document Server

    Buffat, Xavier; Metral, Elias; Ribes Metidieri, Ariadna; Barranco Garcia, Javier; Goncalves Jorge, Patrik; Pieloni, Tatiana; Tambasco, Claudia; CERN. Geneva. ATS Department

    2018-01-01

    This note summarised the status of the studies on the coherent beam-beam effects in the HL-LHC project. It is shown that the obit, tune, chromaticity and dynamic β effects due to head-on and long-range beam-beam interactions are tolerable without dedicated mitigations in the baseline scenario. The stability of coherent beam-beam modes under the influence of the beam coupling impedance is evaluated, as well as the impact of the beam-beam induced tune spread on the Landau damping of single beam head-tail modes of oscillation. Since the beam stability is marginal at the end of the squeeze for the ultimate scenario, it is suggested to use the ATS optics to increase the effect of the octupoles at constant current, thus providing sufficient margins. Measurements suggesting that the transverse damper noise has to be significantly reduced to allow for operation with large beam-beam parameter are shown.

  7. Head-On Beam-Beam Interactions in High-Energy Hadron Colliders. GPU-Powered Modelling of Nonlinear Effects

    CERN Document Server

    AUTHOR|(CDS)2160109; Støvneng, Jon Andreas

    2017-08-15

    The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strength of the beam-beam interactions will be higher after the upgrade to the High-Luminosity Large Hadron Collider, and also in the next generation of machines, as the Future Circular Hadron Collider. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and drives resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. For this thesis, a new code named CABIN (Cuda-Accelerated Beam-beam Interaction) has been developed to study the limitations caused by the impact of strong beam-beam interactions. In particular, the evolution of the beam emittance and beam intensity has been monitored to study the impact quantitatively...

  8. Parallel Beam-Beam Simulation Incorporating Multiple Bunches and Multiple Interaction Regions

    CERN Document Server

    Jones, F W; Pieloni, T

    2007-01-01

    The simulation code COMBI has been developed to enable the study of coherent beam-beam effects in the full collision scenario of the LHC, with multiple bunches interacting at multiple crossing points over many turns. The program structure and input are conceived in a general way which allows arbitrary numbers and placements of bunches and interaction points (IP's), together with procedural options for head-on and parasitic collisions (in the strong-strong sense), beam transport, statistics gathering, harmonic analysis, and periodic output of simulation data. The scale of this problem, once we go beyond the simplest case of a pair of bunches interacting once per turn, quickly escalates into the parallel computing arena, and herein we will describe the construction of an MPI-based version of COMBI able to utilize arbitrary numbers of processors to support efficient calculation of multi-bunch multi-IP interactions and transport. Implementing the parallel version did not require extensive disruption of the basic ...

  9. Synchro-betatron resonances driven by the beam-beam interaction

    International Nuclear Information System (INIS)

    Furman, M.A.

    1994-01-01

    We present a selective summary of the discussions on beam-beam-driven synchrobetatron resonances at the 6th Advanced ICFA Beam Dynamics Workshop on the subject ''Synchro-Betatron Resonances,'' held in Funchal (Madeira, Portugal), October 24--30, 1993

  10. Beam-Beam Interaction, Electron Cloud and Intrabeam Scattering for Proton Super-bunches

    CERN Document Server

    Ruggiero, F; Rumolo, Giovanni; Papaphilippou, Y

    2003-01-01

    Super-bunches are long bunches with a flat longitudinal profile, which could potentially increase the LHC luminosity in a future upgrade. We present example parameters and discuss a variety of issues related to such superbunches, including beam-beam tune shift, tune footprints, crossing schemes, luminosity, intrabeam scattering, and electron cloud. We highlight the benefits, disadvantages and open questions.

  11. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  12. Beam-beam phenomenology

    International Nuclear Information System (INIS)

    Teng, L.C.

    1980-01-01

    In colliding beam storage rings the beam collision regions are generally so short that the beam-beam interaction can be considered as a series of evenly spaced non-linear kicks superimposed on otherwise stable linear oscillations. Most of the numerical studies on computers were carried out in just this manner. But for some reason this model has not been extensively employed in analytical studies. This is perhaps because all analytical work has so far been done by mathematicians pursuing general transcendental features of non-linear mechanics for whom this specific model of the specific system of colliding beams is too parochial and too repugnantly physical. Be that as it may, this model is of direct interest to accelerator physicists and is amenable to (1) further simplification, (2) physical approximation, and (3) solution by analogy to known phenomena

  13. Importance of beam-beam tune spread to collective beam-beam instability in hadron colliders

    International Nuclear Information System (INIS)

    Jin Lihui; Shi Jicong

    2004-01-01

    In hadron colliders, electron-beam compensation of beam-beam tune spread has been explored for a reduction of beam-beam effects. In this paper, effects of the tune-spread compensation on beam-beam instabilities were studied with a self-consistent beam-beam simulation in model lattices of Tevatron and Large Hodron Collider. It was found that the reduction of the tune spread with the electron-beam compensation could induce a coherent beam-beam instability. The merit of the compensation with different degrees of tune-spread reduction was evaluated based on beam-size growth. When two beams have a same betatron tune, the compensation could do more harm than good to the beams when only beam-beam effects are considered. If a tune split between two beams is large enough, the compensation with a small reduction of the tune spread could benefit beams as Landau damping suppresses the coherent beam-beam instability. The result indicates that nonlinear (nonintegrable) beam-beam effects could dominate beam dynamics and a reduction of beam-beam tune spread by introducing additional beam-beam interactions and reducing Landau damping may not improve the stability of beams

  14. Beam-beam deflections as an interaction point diagnostic for the SLC

    International Nuclear Information System (INIS)

    Bambade, P.; Erickson, R.

    1986-05-01

    A technique is described for non-destructive measurement and monitoring of the steering offset of the electron and positron beams at the interaction point of the SLC, based on using stripline beam-position monitors to measure the centroid of one beam as it is deflected by the opposing beam. This technique is also expected to provide diagnostic information related to the spot size of the micron-size beams

  15. Beam-beam interaction in high energy linear electron-positron colliders

    International Nuclear Information System (INIS)

    Ritter, S.

    1985-04-01

    The interaction of high energy electron and positron beams in a linear collider has been investigated using a macroparticle Monte Carlo method based on a Cloud-In-Cells plasma simulation scheme. Density evolutions, luminosities, energy and angular distributions for electrons (positrons) and synchrotron photons are calculated. Beside beams with a symmetric transverse profile also flat beams are considered. A reasonably good agreement to alternative computer calculations as well as to an analytical approximation for the energy spectrum of synchrotron photons has been obtained. (author)

  16. Observations and measurements of dynamic effects due to beam-beam interactions in the LHC and extrapolation to the FCC-hh

    CERN Document Server

    Goncalves Jorge, Patrik

    The Future Circular hadron-hadron Collider (FCC-hh) is a design study for a 100 TeV centre-of-mass energy. The dynamics of the beams in such a collider poses many challenges, in particular the amount of energy stored in each beam (8.4 GJ) makes them very destructive and therefore requires a tight control of the machine and beam parameters during the full cycle in order to avoid damages and reach the collider designed performances. The FCC-hh features an increase of the beam brightness during the cycle due to the presence of synchrotron radiation damping at high energy. As a result, the electromagnetic forces that the two beams exert on each other, the so-called beam-beam forces, are enhanced and might become an issue for the safe operation of the machine. In this new regime, the impact of the beam-beam interaction on the optics becomes non-negligible. In this master thesis, for the first time, the impact of the beam-beam interaction on the optics ($\\beta$-beating) is measured in a hadron collider (LHC). The e...

  17. Compensation of the long-range beam-beam interactions as a path towards new configurations for the high luminosity LHC

    Directory of Open Access Journals (Sweden)

    Stéphane Fartoukh

    2015-12-01

    Full Text Available Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β^{*} and type of optics (flat or round, and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the long-range beam-beam effects [J. P. Koutchouk, CERN Report No. LHC-Project-Note 223, 2000], therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the final focus quadrupoles. In this paper, a semianalytical approach is developed for the compensation of the long-range beam-beam interactions with current wires. This reveals the possibility of achieving optimal correction through a careful adjustment of the aspect ratio of the β functions at the wire position. We consider the baseline luminosity upgrade plan of the Large Hadron Collider (HL-LHC project, and compare it to alternative scenarios, or so-called “configurations,” where modifications are applied to optics, crossing angle, or orientation of the crossing plane in the two low-β insertions of the ring. For all these configurations, the beneficial impact of beam-beam compensation devices is then demonstrated on the tune footprint, the dynamical aperture, and/or the frequency map analysis of the nonlinear beam dynamics as the main figures of merit.

  18. GPU-Powered Modelling of Nonlinear Effects due to Head-On Beam-Beam Interactions in High-Energy Hadron Colliders.

    CERN Document Server

    Furuseth, Sondre

    2017-01-01

    The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. This report discusses results from an implementation of the weak-strong model, studying the effects of head-on beam-beam interactions. The assumptions has been shown to be valid for configurations where the growth and losses of the beam are small. The tracking has been done using an original code which applies graphic cards to reduce the computation time. The bunches in the beams have been modelled cylindrically symmetrical, based on a Gaussian distribution in three dimensions. This choice fits well with bunches...

  19. Compensation of the long-range beam-beam interactions as a path towards new configurations for the High Luminosity LHC

    CERN Document Server

    AUTHOR|(SzGeCERN)390904; Papaphilippou, Yannis; Shatilov, Dmitry

    2015-01-01

    Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β* and type of optics (flat or round), and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the longrange beam-beam effects, therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the fi...

  20. Beam-beam-induced orbit effects at LHC

    International Nuclear Information System (INIS)

    Schaumann, M; Fernandez, R Alemany

    2014-01-01

    For high bunch intensities the long-range beam-beam interactions are strong enough to provoke effects on the orbit. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are presented in this paper

  1. Simulation of Beam-Beam Background at CLIC

    CERN Document Server

    Sailer, Andre

    2010-01-01

    The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GuineaPig and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam background hitting the vertex detector.

  2. Simulation of Beam-Beam Background at CLIC

    CERN Document Server

    Sailer, A

    2010-01-01

    The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GUINEAPIG and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam back- ground hitting the vertex detector.

  3. Report of the group on beam-beam effects in circular colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1991-05-01

    We present a summary of the discussions and conclusions of the working group on beam-beam effects for circular colliders. This group was part of the larger beam-beam dynamics group at the 7th ICFA Workshop on Beam Dynamics, on the subject ''Beam-Beam and Beam-Radiation Interactions,'' held at UCLA, May 13--16, 1991. 15 refs

  4. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  5. Dynamical chaos and beam-beam models

    International Nuclear Information System (INIS)

    Izrailev, F.M.

    1990-01-01

    Some aspects of the nonlinear dynamics of beam-beam interaction for simple one-dimensional and two-dimensional models of round and flat beams are discussed. The main attention is paid to the stochasticity threshold due to the overlapping of nonlinear resonances. The peculiarities of a round beam are investigated in view of using the round beams in storage rings to get high luminosity. 16 refs.; 7 figs

  6. OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC

    International Nuclear Information System (INIS)

    FISCHER, W.; BLASKIEWICZ, M.; BRENNAN, J.M.; CAMERON, P.; CONNOLLY, R.; MONTAG, C.; PEGGS, S.; PILAT, F.; PTITSYN, V.; TEPIKIAN, S.; TRBOJEVIC, D.; VAN ZEIJTS, J.

    2003-01-01

    RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far

  7. Observed Orbit Effects during Long Range Beam-Beam Studies

    CERN Document Server

    Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D

    2012-01-01

    Possible limitations due to long range beam-beam effects at the LHC have been studied and are presented in this note. With a larger number of bunches and collisions in all interaction points, the crossing angles were reduced to enhance long range beam-beam effects. The analysis of the effects on the dynamic aperture and losses are documented in [1]. This note concentrates on the bunch-by-bunch orbit effects observed during the experiment.

  8. Tune distributions and effective tune spread from beam-beam interactions and the consequences for Landau damping in the LHC

    CERN Document Server

    Herr, Werner

    2003-01-01

    We have calculated the tune distribution functions in the presence of beam-beam effects in order to evaluate the efect of Landau damping of instabilities driven by the impedance. The corresponding stability diagrams have been computed and the limits on the transverse impedance have be derived.

  9. Coherent beam-beam effect

    International Nuclear Information System (INIS)

    Chao, A.W.; Keil, E.

    1979-06-01

    The stability of the coherent beam-beam effect between rigid bunches is studied analytically and numerically for a linear force by evaluating eigenvalues. For a realistic force, the stability is investigated by following the bunches for many revolutions. 4 refs., 13 figs., 2 tabs

  10. Observations of beam-beam effects in the LHC 2011

    International Nuclear Information System (INIS)

    Herr, W.; Alemany, R.; Buffat, X.; Calaga, R.; Giachino, R.; Papotti, G.; Pieloni, T.; Trad, G.; Schaumann, M.

    2012-01-01

    We have reported on the first studies of beam-beam effects in the LHC with high intensity, high brightness beams and can summarize the results as follows. The effect of the beam-beam interaction on the beam dynamics is clearly established. The LHC allows very large head-on tune shifts above nominal. The effect of long range interactions on the beam lifetime and losses (dynamic aperture) is clearly visible. The number of head-on and/or long range interactions important for losses and all predicted PACMAN effects have been observed. All observations are in good agreement with the expectations

  11. Beam-beam diagnostics from closed-orbit distortion

    International Nuclear Information System (INIS)

    Furman, M.; Chin, Y.H.; Eden, J.; Kozanecki, W.; Tennyson, J.; Ziemann, V.

    1992-07-01

    We study the applicability of beam-beam deflection techniques as a tuning tool for asymmetric B factories, focusing on PEP-II as an example. Assuming that the closed orbits of the two beams are separated vertically at the interaction point by a local orbit bump that is nominally closed, we calculate the residual beam orbit distortions due to the beam-beam interaction. Difference orbit measurements, performed at points conveniently distant from the interaction point (IP), provide distinct signatures that can be used to maintain the beams in collision and perform detailed optical diagnostics at the IP. A proposal to test this method experimentally at the TRISTAN ring is briefly discussed

  12. Beam-beam studies for FCC-hh

    CERN Document Server

    AUTHOR|(CDS)2068329; Pieloni, Tatiana; Buffat, Xavier; Furuseth, Sondre Vik

    2017-01-01

    The Future Circular Collider hadron-hadron (FCC-hh) design study is currently exploring different IR design possibilities including round and flat optics or different crossing schemes. The present study intends to evaluate each scenario from the beam-beam effects point of view. In particular the single particle long term stability to maximize beam lifetimes and luminosity reach is used to quantify the differences. The impact of strong head on interactions on the beam quality and lifetime is addressed by means of GPU accelerated simulations code featuring a weak-strong 6-dimensional beam-beam interaction.

  13. Survey of beam-beam limitations

    International Nuclear Information System (INIS)

    Courant, E.; Cornacchia, M.; Donald, M.M.R.; Evans, L.R.; Tazzari, S.; Wilson, E.J.N.

    1979-01-01

    The effect of beam-beam interaction is known to limit the luminosity of electron-positron storage rings and will, no doubt, limit the proton-antiproton collision scheme for the SPS. While theorists are struggling to explain this phenomenon it is more instructive to list their failures than their rather limited successes, in the hope that experiments may emerge which will direct their endeavors. The search for a description of a nonlinear system as it approaches the limit in which ordered motion breaks down, is the nub of the problem. It has engaged many fine mathematical intellects for decades and will no doubt continue to do so long after ISABELLE, the p antip and LEP are past achievements. Empirical scaling laws are emerging which relate electron machines to each other but their extrapolation to proton machines remain a very speculative exercise. Experimental data on proton limits is confined to one machine, the ISR, which does not normally suffer the beam-beam effect and where it must be artificially induced or simulated. This machine is also very different in important ways from the p antip collider. The gloomy picture which has emerged recently is that the fixed limits which were conventionally assumed for proton and electron machines can only be said to be valid for the machines which engendered them - the best guess that could be made at the time. They are very difficult to extrapolate to other sets of parameters

  14. 'Electron compression' of beam-beam footprint in the Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.; Finley, D.A.

    1997-08-01

    The beam-beam interaction in the Tevatron collider sets some limits on bunch intensity and luminosity. These limits are caused by a tune spread in each bunch which is mostly due to head-on collisions, but there is also a bunch-to-bunch tune spread due to parasitic collisions in multibunch operation. We describe a counter-traveling electron beam which can be used to eliminate these effects, and present general considerations and physics limitations of such a device which provides 'electron compression' of the beam-beam footprint in the Tevatron

  15. Study of beam-beam long range compensation with octupoles

    CERN Document Server

    AUTHOR|(CDS)2068329; Pieloni, Tatiana; Buffat, Xavier; Tambasco, Claudia

    2017-01-01

    Long range beam-beam effects are responsible for particle losses and define fundamental operational parameters of colliders (i.e. crossing angles, intensities, emittances, ${\\beta}$${^∗}$). In this study we propose octuple magnets as a possible scheme to efficiently compensate long-range beam-beam interactions with a global correction scheme. The impact and improvements on the dynamic aperture of colliding beams together with estimates of the luminosity potentials are dis- cussed for the HL-LHC upgrade and extrapolations made for the FCC project.

  16. A summary of some beam-beam models

    International Nuclear Information System (INIS)

    Chao, A.W.

    1989-01-01

    Two categories of theoretical models for the beam-beam interaction are reviewed: the linear-lens models and the single-resonance models. In a linear-lens model, the beam-beam force is linearized and represented by a localized linear lens. Analyses of incoherent single particle effects can be performed exactly in these models by using matrix techniques. Although the results do not agree with the experimental observations in many respects, the linear-lens models constitute a starting point of our understanding of the beam-beam interaction. In the single-resonance models, one is concerned with the possible incoherent instabilities as the betatron tune of some of the particles is close to a certain rational number. It is assumed in these models that one and only one such rational number dominates the single-particle beam-beam effects. It is found that static single resonances cannot explain many of the experimental results. Some attempts have been made to modify the static single-resonance theory by including some mechanisms for diffusive tune fluctuations or periodic tune modulations. These modified single-resonance models have met only with some limited qualitative success. 21 refs., 13 figs

  17. MD 2197: Experimental studies of Landau damping by means of Beam Transfer Function measurements in the presence of beam-beam interactions and diffusive mechanisms

    CERN Document Server

    Tambasco, Claudia; Barranco Garcia, Javier; Boccardi, Andrea; Buffat, Xavier; Bruce, Roderik; Gasior, Marek; Hostettler, Michi; Lefevre, Thibaut; Louro Alves, Diogo Miguel; Metral, Elias; Persson, Tobias Hakan Bjorn; Pieloni, Tatiana; Pojer, Mirko; Salvachua Ferrando, Belen Maria; Solfaroli Camillocci, Matteo; CERN. Geneva. ATS Department

    2018-01-01

    Beam Transfer Function (BTF) measurements are direct measurement of the stability diagrams that define the stability threshold of coherent beam instabilities driven by the impedance. At the LHC, some coherent instabilities at flat top energy are still not fully understood and the BTF measurements provide a method to experimentally probe the Landau damping of the proton beams. The BTF response is sensitive to the particle distribution changes and contain information about the transverse tune spread in the beams. The BTF system has been installed in the LHC in the 2015 in order to investigate the Landau damping at different stages of the operational cycle, machine configurations (different octupole currents, crossing angles, tunes etc...) and in presence of beam-beam excited resonances that may provoke diffusion mechanisms with a consequence change of Landau damping. Past MDs showed some difficulties for the reconstruction of the stability diagram from BTF measurements and several improvements on the BTF sy...

  18. Beam-beam issues in asymmetric colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  19. Transverse equilibria in linear collider beam-beam collisions

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Chen, Pisin

    1991-01-01

    It has been observed in simulations of the beam-beam interaction in linear colliders that a near equilibrium pinched state of the colliding beams develops when the disruption parameter is large (D much-gt 1). In this state the beam transverse density distributions are peaked at center, with long tails. The authors present here an analytical model of the equilibrium approached by the beams, that of a generalized Bennett pinch which develops through collisionless damping due to the strong nonlinearity of the beam-beam interaction. In order to calculate the equilibrium pinched beam size, an estimation of the rms emittance growth is made which takes into account the partial adiabaticity of the collision. This pinched beam size is used to derive the luminosity enhancement factors whose scaling is in agreement with the simulation results for both D and thermal factor A = σ z /β * large, and explains the previously noted cubic relationship between round and flat beam enhancement factors

  20. Beam-beam force and storage ring parameters

    International Nuclear Information System (INIS)

    Herrera, J.C.

    1979-01-01

    The fundamental aspects of the beam--beam force as it occurs in Intersecting Storage Rings are reported. The way in which the effect of the beam--particle electromagnetic force (weak--strong interaction) is different in the case of unbunched proton beams which cross each other at an angle (as in the ISR and in ISABELLE) is shown, as compared to the case of electron--positron beams where bunches collide head-on

  1. Beam-beam depolarization in SPEAR and PEP

    International Nuclear Information System (INIS)

    Montague, B.W.

    1977-01-01

    In this note some approximate estimates are made of depolarization due to beam-beam forces in SPEAR and PEP, using the results of a calculation by Kondratenko. The model assumes head-on collisions between bunches of Gaussian distribution in the transverse directions; the force on the weak-beam particle is taken to be a δ-function at the interaction point. 1 ref

  2. Instability of compensated beam-beam collisions

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Autin, B.; Chen, Pisin.

    1989-01-01

    The beam-beam disruption phenomena in linear colliders are increasingly seen as a source of serious problems for these machines. A plasma compensation scheme, in which the motion of the plasma electrons in the presence of the colliding beams provides neutralizing charge and current densities, has been proposed and studied. But natural alternative to this scheme is to consider the overlapping of nearly identical high energy e + and e/sup /minus// bunches, and the collision of two such pairs - in other words, collision of two opposing relativistic positronium plasmas. It should be noticed that while the luminosity for all collisions is increased by a factor of four in this scheme, the event rate for e + e/sup /minus// collisions is only increased by a factor of two. The other factor of two corresponds to the addition of e + e + and e/sup /minus//e/sup /minus// collisions to the interaction point. This beam compensation scheme, which has been examined through computer simulation by Balakin and Solyak in the Soviet Union, promises full neutralization of beam charges and currents. These numerical investigations have shown that plasma instabilities exist in this nominally neutral system. Although the implementation of this idea seems technically daunting, the potential benefits (beamstrahlung and disruption suppression, relaxation of final focus system constraints) are such that we should consider the physics of these collisions further. In the remainder of this paper, we theoretically analyze the issues of stability and bunch parameter tolerances in this scheme. 11 refs

  3. Simulation of beam-beam effects in tevatron

    International Nuclear Information System (INIS)

    Mishra, C.S.; Assadi, S.; Talman, R.

    1995-08-01

    The Fermilab accelerator complex is in the middle of an upgrade plan Fermilab III. In the last phase of this upgrade the luminosity of the Tevatron will increase by at least one order of magnitude. In order to keep the number of interactions per crossing manageable for experiments, the number of bunches will be increased from 6 x 6 to 36 x 36 and finally to ∼100 x 100 bunches. The beam dynamics of the Tevatron has been studied from Beam-Beam effect point of view in a ''Strong-Weak'' representation with a single particle being tracked in presence of other beam. This paper describes the beam-beam effect in 6 x 6 operation of Tevatron

  4. Impact of beam-beam effects on precision luminosity measurements at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Rimbault, C [LAL, Univ Paris-Sud, IN2P3/CNRS, Orsay (France); Bambade, P [LAL, Univ Paris-Sud, IN2P3/CNRS, Orsay (France); Moenig, K [DESY, Zeuthen (Germany); Schulte, D [CERN, Geneva (Switzerland)

    2007-09-15

    In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

  5. Impact of beam-beam effects on precision luminosity measurements at the ILC

    CERN Document Server

    Rimbault, C; Mönig, K; Schulte, D

    2007-01-01

    In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

  6. Study of Beam-Beam Effects at PEP-II

    International Nuclear Information System (INIS)

    Narsky, I

    2004-01-01

    Using a self-consistent three-dimensional simulation running on parallel supercomputers, we have modeled the beam-beam interaction at the PEP-II asymmetric e + e - collider. To provide guidance for luminosity improvement, we scanned the tunes and currents in both rings and computed their impact on the luminosity and transverse beam sizes. We also studied the effects of colliding the beams with a small crossing angle. Where possible, the code was benchmarked against experimental measurements of luminosity and beam sizes, yielding an acceptable agreement

  7. Successful Beam-Beam Tuneshift Compensation

    Energy Technology Data Exchange (ETDEWEB)

    Bishofberger, Kip Aaron [Univ. of California, Los Angeles, CA (United States)

    2005-01-01

    The performance of synchrotron colliders has been limited by the beam-beam limit, a maximum tuneshift that colliding bunches could sustain. Due to bunch-to-bunch tune variation and intra-bunch tune spread, larger tuneshifts produce severe emittance growth. Breaking through this constraint has been viewed as impossible for several decades. This dissertation introduces the physics of ultra-relativistic synchrotrons and low-energy electron beams, with emphasis placed on the limits of the Tevatron and the needs of a tuneshift-compensation device. A detailed analysis of the Tevatron Electron Lens (TEL) is given, comparing theoretical models to experimental data whenever possible. Finally, results of Tevatron operations with inclusion of the TEL are presented and analyzed. It is shown that the TEL provides a way to shatter the previously inescapable beam-beam limit.

  8. A symplectic coherent beam-beam model

    International Nuclear Information System (INIS)

    Furman, M.A.

    1989-05-01

    We consider a simple one-dimensional model to study the effects of the beam-beam force on the coherent dynamics of colliding beams. The key ingredient is a linearized beam-beam kick. We study only the quadrupole modes, with the dynamical variables being the 2nd-order moments of the canonical variables q, p. Our model is self-consistent in the sense that no higher order moments are generated by the linearized beam-beam kicks, and that the only source of violation of symplecticity is the radiation. We discuss the round beam case only, in which vertical and horizontal quantities are assumed to be equal (though they may be different in the two beams). Depending on the values of the tune and beam intensity, we observe steady states in which otherwise identical bunches have sizes that are equal, or unequal, or periodic, or behave chaotically from turn to turn. Possible implications of luminosity saturation with increasing beam intensity are discussed. Finally, we present some preliminary applications to an asymmetric collider. 8 refs., 8 figs

  9. Experimental observations and theoretical models for beam-beam phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kheifets, S.

    1981-03-01

    The beam-beam interaction in storage rings exhibits all the characteristics of nonintegrable dynamical systems. Here one finds all kinds of resonances, closed orbits, stable and unstable fixed points, stochastic layers, chaotic behavior, diffusion, etc. The storage ring itself being an expensive device nevertheless while constructed and put into operation presents a good opportunity of experimentally studying the long-time behavior of both conservative (proton machines) and nonconservative (electron machines) dynamical systems - the number of bunch-bunch interactions routinely reaches values of 10/sup 10/-10/sup 11/ and could be increased by decreasing the beam current. At the same time the beam-beam interaction puts practical limits for the yield of the storage ring. This phenomenon not only determines the design value of main storage ring parameters (luminosity, space charge parameters, beam current), but also in fact prevents many of the existing storage rings from achieving design parameters. Hence, the problem has great practical importance along with its enormous theoretical interest. A brief overview of the problem is presented.

  10. Experimental observations and theoretical models for beam-beam phenomena

    International Nuclear Information System (INIS)

    Kheifets, S.

    1981-03-01

    The beam-beam interaction in storage rings exhibits all the characteristics of nonintegrable dynamical systems. Here one finds all kinds of resonances, closed orbits, stable and unstable fixed points, stochastic layers, chaotic behavior, diffusion, etc. The storage ring itself being an expensive device nevertheless while constructed and put into operation presents a good opportunity of experimentally studying the long-time behavior of both conservative (proton machines) and nonconservative (electron machines) dynamical systems - the number of bunch-bunch interactions routinely reaches values of 10 10 -10 11 and could be increased by decreasing the beam current. At the same time the beam-beam interaction puts practical limits for the yield of the storage ring. This phenomenon not only determines the design value of main storage ring parameters (luminosity, space charge parameters, beam current), but also in fact prevents many of the existing storage rings from achieving design parameters. Hence, the problem has great practical importance along with its enormous theoretical interest. A brief overview of the problem is presented

  11. Long-range beam-beam experiments in the relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Calaga, R; Fischer, W; Milas, N; Robert-Demolaize, G

    2014-01-01

    Long-range beam-beam effects are a potential limit to the LHC performance with the nominal design parameters, and certain upgrade scenarios under discussion. To mitigate long-range effects, current carrying wires parallel to the beam were proposed and space is reserved in the LHC for such wires. Two current carrying wires were installed in RHIC to study the effect of strong long-range beam-beam effects in a collider, as well as test the compensation of a single long-range interaction. The experimental data were used to benchmark simulations. We summarize this work

  12. The effects of betatron phase advances on beam-beam and its compensation in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y.; Fischer, W.; Gu, X.; Tepikian, S.; Trbojevic, D.

    2011-03-28

    In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

  13. Numerical Simulation of Beam-Beam Effects in the Proposed Electron-Ion Colider at Jefferson Lab

    International Nuclear Information System (INIS)

    Terzic, Balsa; Zhang, Yuhong

    2010-01-01

    One key limiting factor to a collider luminosity is beam-beam interactions which usually can cause serious emittance growth of colliding beams and fast reduction of luminosity. Such nonlinear collective beam effect can be a very serious design challenge when the machine parameters are pushed into a new regime. In this paper, we present simulation studies of the beam-beam effect for a medium energy ring-ring electron-ion collider based on CEBAF.

  14. Beam-Beam Effects in the SPS Proton-Anti Proton Collider

    CERN Document Server

    Cornelis, K.

    2014-01-01

    During the proton-anti proton collider run several experiments were carried out in order to understand the effect of the beam-beam interaction on backgrounds and lifetimes. In this talk a selection of these experiments will be presented. From these experiments, the importance of relative beam sizes and tune ripple could be demonstrated.

  15. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    International Nuclear Information System (INIS)

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.-P.; Sterbini, G.; Zimmermann, F.; Kim, H.-J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

    2009-01-01

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations

  16. Beam-beam limit in e+e- circular colliders

    International Nuclear Information System (INIS)

    Ohmi, K.; Tawada, M.; Kamada, S.; Oide, K.; Cai, Y.; Qiang, J.

    2004-01-01

    Beam-beam effects limit the luminosity of circular colliders. Once the bunch population exceeds a threshold, the luminosity increases at a slower rate. This phenomenon is called the beam-beam limit. Onset of the beam-beam limit has been analyzed with various simulation methods based on the weak-strong and strong-strong models. We have observed that an incoherent phenomenon is mainly concerned in the beam-beam limit. The simulation have shown that equilibrium distributions of the two colliding beams are distorted from Gaussians when the luminosity is limited. The beam-beam limit is estimated to be ξ∼0.1 for a B factory with damping time of several thousand turns

  17. Beam-beam effects under the influence of external noise

    International Nuclear Information System (INIS)

    Ohmi, K

    2014-01-01

    Fast external noise, which gives fluctuation into the beam orbit, is discussed in connection with beam-beam effects. Phase noise from crab cavities and detection devices (position monitor) and kicker noise from the bunch by bunch feedback system are the sources. Beam-beam collisions with fast orbit fluctuations with turn by turn or multi-turn correlations, cause emittance growth and luminosity degradation. We discuss the tolerance of the noise amplitude for LHC and HL-LHC

  18. Combined phenomena of beam-beam and beam-electron cloud interactionsin circular e^{+}e^{-} colliders

    Directory of Open Access Journals (Sweden)

    Kazuhito Ohmi

    2002-10-01

    Full Text Available An electron cloud causes various effects in high intensity positron storage rings. The positron beam and the electron cloud can be considered a typical two-stream system with a certain plasma frequency. Beam-beam interaction is another important effect for high luminosity circular colliders. Colliding two beams can be considered as a two-stream system with another plasma frequency. We study the combined phenomena of the beam-electron cloud and beam-beam interactions from a viewpoint of two complex two-stream effects with two plasma frequencies.

  19. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    CERN Document Server

    AUTHOR|(CDS)2070952; Valishev, Aleksander; Shatilov, Dmitry

    2015-01-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical β∗ values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  20. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    Energy Technology Data Exchange (ETDEWEB)

    Fartoukh, Stephane [CERN; Valishev, Alexander [Fermilab; Shatilov, Dmitry [BINP, Novosibirsk

    2015-06-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  1. Beam-beam dynamics during the injection process at the PEP-II B-Factory

    International Nuclear Information System (INIS)

    Chin, Yong Ho.

    1991-10-01

    This paper is concerned with beam-beam effects during the injection process at the proposed asymmetric SLAC/LBL/LLNL B-Factory based on PEP (PEP-2). For symmetric colliders, the primary source of the beam-beam effect is the head-on collision at the interaction point (IP), and this effect can be mitigated by separating the beams during the injection process. For an asymmetric collider, which intrinsically consists of two separate rings, the bunches not only collide at the IP but experience a long-range beam-beam force on the way into and out of the IP region. These collisions are called ''parasitic crossings (PC).'' The parasitic crossings emerge as a potential source of far stronger beam-beam impact during the injection process for the following reason. In the proposed injection scheme of the APIARY-6.3d design, the bunches are injected horizontally into the two rings with large horizontal offset of 8σ Ox sptm where σ Ox sptm is the nominal horizontal storage ring beam size at the end of the septum magnet. Then, the injected beam starts to travel around the ring oscillating horizontally. For the sake of discussion, let us assume that the beam in the other ring has already been fully stored. When the injected beam arrives at the 1st PC, where the two nominal orbits are separated horizontally by about 7.6 times the nominal horizontal beam size of the low energy ring, it may pass through the other beam far more closely than at the nominal separation distance, or it may even strike the other beam head-on

  2. Beam-beam effect and luminosity in SPEAR

    International Nuclear Information System (INIS)

    Wiedemann, H.

    1980-01-01

    Many measurements on the beam-beam limit in SPEAR have been performed over the past years. The goal for these measurements was to find the proper parameterization of the beam-beam effect. All measurements presented were done with both beams equally blown up by control of the flip-flop phenomenon. Colliding beam measurements were made at energies as low as 600 MeV and together with earlier measurements the author presents the scaling of some relevant storage ring parameters from 600 MeV up to almost 4 GeV. (Auth.)

  3. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-09-11

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  4. Beam-beam effects in the high-pile-up tests of the LHC

    International Nuclear Information System (INIS)

    Trad, G

    2014-01-01

    Investigating the beam-beam limit in the LHC is of great importance, since identifying its source is crucial for the luminosity optimization scenario. Several experiments were carried out to search for this limit and check whether it is dominated by the head-on (HO) or the long-range (LR) interactions. In this paper only the HO collision effects will be considered, tracking the evolution of the maximum tune shift achieved during the dedicated machine developments and the special high pile-up fills

  5. Beam-beam effects in the high-pile-up tests of the LHC

    CERN Document Server

    Trad, G.

    2014-07-17

    Investigating the beam-beam limit in the LHC is of great importance, since identifying its source is crucial for the luminosity optimization scenario. Several experiments were carried out to search for this limit and check whether it is dominated by the head-on (HO) or the long-range (LR) interactions. In this paper only the HO collision effects will be considered, tracking the evolution of the maximum tune shift achieved during the dedicated machine developments and the special high pile-up fills.

  6. Bench-marking beam-beam simulations using coherent quadrupole effects

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Chin, Y.H.

    1992-06-01

    Computer simulations are used extensively in the study of the beam-beam interaction. The proliferation of such codes raises the important question of their reliability, and motivates the development of a dependable set of bench-marks. We argue that rather than detailed quantitative comparisons, the ability of different codes to predict the same qualitative physics should be used as a criterion for such bench-marks. We use the striking phenomenon of coherent quadrupole oscillations as one such bench-mark, and demonstrate that our codes do indeed observe this behaviour. We also suggest some other tests that could be used as bench-marks

  7. Bench-marking beam-beam simulations using coherent quadrupole effects

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Chin, Y.H.

    1992-01-01

    Computer simulations are used extensively in the study of the beam-beam interaction. The proliferation of such codes raises the important question of their reliability, and motivates the development of a dependable set of bench-marks. We argue that rather than detailed quantitative comparisons, the ability of different codes to predict the same qualitative physics should be used as a criterion for such bench-marks. We use the striking phenomenon of coherent quadrupole oscillations as one such bench-mark, and demonstrate that our codes do indeed observe this behavior. We also suggest some other tests that could be used as bench-marks

  8. Beam-beam instability driven by wakefield effects in linear colliders

    CERN Document Server

    Brinkmann, R; Schulte, Daniel

    2002-01-01

    The vertical beam profile distortions induced by wakefield effects in linear colliders (the so-called ``banana effect'') generate a beam-beam instability at the collision point when the vertical disruption parameter is large. We illustrate this effect in the case of the TESLA linear collider project. We specify the tolerance on the associated emittance growth, which translates into tolerances on injection jitter and, for a given tuning procedure, on structure misalignments. We look for possible cures based on fast orbit correction at the interaction point and using a fast luminosity monitor.

  9. Electroproduction of pairs at beam-beam collision

    International Nuclear Information System (INIS)

    Bajer, V.N.; Katkov, V.M.; Strakhovenko, V.M.

    1989-01-01

    Charged particle pair production at beam-beam collision in electron-positron linear colliders has been discussed taking into account a finite size of the beams (both longitudinal and transverse) and end effects. Contributions of the main acting mechanisms are singled out which depend on the energy of initial particles and the masses of created particles. A spectral distribution of produced particles is presented. 15 refs

  10. Beam-Beam Simulations with GUINEA-PIG

    CERN Document Server

    Schulte, Daniel

    1998-01-01

    While the bunches in a linear collider cross only once, due to their small size they experience a strong beam-beam effect. GUINEA-PIG is a code to simulate the impact of this effect on luminosity and back ground. A short overview of the program is given with examples of its application to the back ground strudies for TESLA, the top quark threshold scan and a possible luminosity monitor, as well as some results for CLIC.

  11. Beam-beam collisions and crossing angles in RHIC

    International Nuclear Information System (INIS)

    Peggs, S.

    1999-01-01

    This paper evaluates the strength of head on and parasitic beam-beam collisions in RHIC when the crossing angle is zero. A non-zero crossing angle is not required in normal operation with 120 bunches, thanks to the early separation of the two beams. The RHIC lattice is shown to easily accommodate even conservatively large crossing angles, for example in beam dynamics studies, or in future operational upgrades to as many as 360 bunches per ring. A modest loss in luminosity is incurred when gold ions collide at an angle after 10 hours of storage

  12. Beam-beam effect and luminosity in SPEAR

    International Nuclear Information System (INIS)

    Wiedemann, H.

    1980-07-01

    Measurements performed at SPEAR have been discussed and scaling laws for the maximum luminosity and the maximum linear tune shift parameter with energy are shown. There are two distinct regimes, one below 2 GeV where the linear tune shift parameter scales like xi/sub y/ approx. E 2 4 and the other regime where this parameter is constant xi/sub y/ approx. = 0.05 to 0.06. In the lower energy regime the limit is reached when the vertical beam size is blown up to the acceptance of the storage ring. A significant (< 10%) horizontal beam blow up is not observed and the value of the horizontal linear tune shift parameter xi/sub x/ does not seem to be related to the beam-beam limit

  13. Beam-beam effects for the PEP-II B Factory

    International Nuclear Information System (INIS)

    Furman, M.A.; Eden, J.R.

    1993-05-01

    We present a summary of a fairly extensive study of beam-beam issues that arise in the design of PEP-II. Most of these studies are carried out with ''strong-strong'' multiparticle tracking simulations. We focus on: choice of nominal beam-beam parameter, strength of the parasitic collisions, injection issues, performance and tradeoffs with unequal beam-beam parameters. We comment only briefly on beam lifetime. We conclude that: the beams are sufficiently well separated so that the parasitic collisions are effectively weak; that small inequalities in the beam-beam parameters may imply more comfortable performance margins; and that vertical injection with vertical beam separation is more comfortable than horizontal

  14. Progress with Long-Range Beam-Beam Compensation Studies for High Luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Adriana; et al.

    2017-05-01

    Long-range beam-beam (LRBB) interactions can be a source of emittance growth and beam losses in the LHC during physics and will become even more relevant with the smaller '* and higher bunch intensities foreseen for the High Luminosity LHC upgrade (HL-LHC), in particular if operated without crab cavities. Both beam losses and emittance growth could be mitigated by compensat-ing the non-linear LRBB kick with a correctly placed current carrying wire. Such a compensation scheme is currently being studied in the LHC through a demonstration test using current-bearing wires embedded into col-limator jaws, installed either side of the high luminosity interaction regions. For HL-LHC two options are considered, a current-bearing wire as for the demonstrator, or electron lenses, as the ideal distance between the particle beam and compensating current may be too small to allow the use of solid materials. This paper reports on the ongoing activities for both options, covering the progress of the wire-in-jaw collimators, the foreseen LRBB experiments at the LHC, and first considerations for the design of the electron lenses to ultimately replace material wires for HL-LHC.

  15. Luminosity, Beamstrahlung energy loss and beam-beam deflections for e+e- and e-e- collisions at the ILC with 500 GeV and varying transverse beam sizes

    International Nuclear Information System (INIS)

    Alabau Pons, M.; Bambade, P.; Faus-Golfe, A.

    2006-01-01

    At the interaction point of the International Linear Collider, beam-beam effects due to the strong electromagnetic fields that the bunches experience during collisions cause a mutual focusing, called pinch effect, which enhances the luminosity in the case of e + e - collisions. The opposite is true for e - e - collisions. In this case the luminosity is reduced by mutual defocusing, or anti-pinching. The resulting Beamstrahlung energy loss and beam-beam deflection angles as function of the vertical transverse offset are also different for both modes of operation. The dependence of these quantities with transverse beam sizes are presented for the case of e - e - collisions

  16. The beam-beam limit in asymmetric colliders: Optimization of the B-factory parameter base

    International Nuclear Information System (INIS)

    Tennyson, J.L.

    1990-01-01

    This paper presents a general theory of the beam-beam limit in symmetric and asymmetric lepton ring colliders. It shows how the beam-beam limit in these accelerators affects the maximum attainable luminosity and presents a specific algorithm for parameter base optimization. It is shown that the special problems inherent in asymmetric colliders derive not from the asymmetry, but from the fact that the two beams must be in different rings. Computer simulation experiments are used to demonstrate the various phenomena discussed in the theory

  17. Beam-beam studies for the proposed SLAC/LBL/LLNL B Factory

    International Nuclear Information System (INIS)

    Furman, M.A.

    1991-05-01

    We present a summary of beam-beam dynamics studies that have been carried out to date for the proposed SLAC/LBL/LLNL B Factory. Most of the material presented here is contained in the proposal's Conceptual Design Report, although post-CDR studies are also presented. 15 refs., 6 figs., 2 tabs

  18. Large Scale Beam-beam Simulations for the CERN LHC using Distributed Computing

    CERN Document Server

    Herr, Werner; McIntosh, E; Schmidt, F

    2006-01-01

    We report on a large scale simulation of beam-beam effects for the CERN Large Hadron Collider (LHC). The stability of particles which experience head-on and long-range beam-beam effects was investigated for different optical configurations and machine imperfections. To cover the interesting parameter space required computing resources not available at CERN. The necessary resources were available in the LHC@home project, based on the BOINC platform. At present, this project makes more than 60000 hosts available for distributed computing. We shall discuss our experience using this system during a simulation campaign of more than six months and describe the tools and procedures necessary to ensure consistent results. The results from this extended study are presented and future plans are discussed.

  19. Future e+e- linear colliders and beam-beam effects

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1986-05-01

    Numerous concepts, ranging from conventional to highly exotic, hae been proposed for the acceleration of electrons and positrons to very high energies. For any such concept to be viable, it must be possible to produce from it a set of consistent parameters for one of these ''benchmark'' machines. Attention is directed to the choice of parameters for a collider in the 300 GeV energy range, operating at a gradient on the order of 200 MV/m, using X-band power sources to drive a conventional disk-loaded accelerating structure. These rf power sources, while not completely conventional represent a reasonable extrapolation from present technology. The choice of linac parameters is strongly coupled to various beam-beam effects which take place when the electron and positron bunches collide. We summarize these beam-beam effects, and then return to the rf design of a 650 GeV center-of-mass collider. 14 refs

  20. Evaluation of the BEAM--BEAM effect in PEP using Myer's simulation program

    International Nuclear Information System (INIS)

    Hutton, A.

    1982-09-01

    The program BEAM BEAM written by Steve Myers for the LEP machine at CERN has given encouraging results in the simulation of the beam-beam effect in electron-positron storage rings. It therefore seemed worthwhile to apply the program to PEP with two main intentions. Firstly, to confirm the validity of the program by comparison with experimental data from previous PEP runs and secondly, to search for an improvement in the operating conditions of PEP. Clearly a successful prediction would also enhance the credibility of the program. The program itself has been extensively described in the literature and will not be repeated here, except for some comments of direct relevance to the present simulation. 14 refs., 15 figs., 4 tabs

  1. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: - Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. - Deconvolution of the luminosity spectrum distortion due to the ISR emission. - Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  2. Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

    CERN Document Server

    Lukic, Strahinja

    2013-01-01

    Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: -> Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. -> Deconvolution of the luminosity spectrum distortion due to the ISR emission. -> Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

  3. Detection of coherent beam-beam modes with digitized beam position monitor signals

    CERN Document Server

    Stancari, G.; White, S.M.

    2014-01-01

    A system for bunch-by-bunch detection of transverse proton and antiproton coherent oscillations in the Fermilab Tevatron collider is described. It is based on the signal from a single beam-position monitor located in a region of the ring with large amplitude functions. The signal is digitized over a large number of turns and Fourier-analyzed offline with a dedicated algorithm. To enhance the signal, band-limited noise is applied to the beam for about 1 s. This excitation does not adversely affect the circulating beams even at high luminosities. The device has a response time of a few seconds, a frequency resolution of $1.6\\times 10^{-5}$ in fractional tune, and it is sensitive to oscillation amplitudes of 60 nm. It complements Schottky detectors as a diagnostic tool for tunes, tune spreads, and beam-beam effects. Measurements of coherent mode spectra are presented and compared with models of beam-beam oscillations.

  4. Beam-Beam Simulation of Crab Cavity White Noise for LHC Upgrade

    CERN Document Server

    Qiang, J; Pieloni, Tatiana; Ohmi, Kazuhito

    2015-01-01

    High luminosity LHC upgrade will improve the luminosity of the current LHC operation by an order of magnitude. Crab cavity as a critical component for compensating luminosity loss from large crossing angle collision and also providing luminosity leveling for the LHC upgrade is being actively pursued. In this paper, we will report on the study of potential effects of the crab cavity white noise errors on the beam luminosity lifetime based on strong-strong beam-beam simulations.

  5. Beam beam tune shifts for 36 bunch operation in the Tevatron

    International Nuclear Information System (INIS)

    Bagley, P.

    1996-10-01

    We are preparing to upgrade the Tevatron Collider from 6 to 36 bunch operation. The 36 bunches are in 3 ''trains'' of 12 bunches. The spacing between bunches within a train is 21 RF buckets (53.106 MHz) and 139 empty buckets separate the trains. Because the 36 bunches are not evenly spaced around the machine, the different bunches within a train pass the opposing bunches at different points in the ring and so feel different beam beam effects. Through most of the machine the beams have helical separation, so these are mainly long range beam beam effects. As a first, very simple step, we've looked at the differences in the tunes of the different anti-proton (anti p) bunches. During the 36 bunch studies in Fall 1995, we used a new tune measurement system to measure these in several different machine conditions. We compare these measurements to calculations of the tunes for a anti p with zero transverse and longitudinal oscillation amplitudes. We discuss experimental problems, and the assumptions, approximations, and effects included in the calculations. Our main intent is to gain confidence that we can accurately model beam beam effects in the Tevatron

  6. Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies

    CERN Document Server

    Sailer, André; Lohse, Thomas

    2013-01-10

    The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

  7. Investigation of the flip-flop beam-beam effect in SPEAR

    International Nuclear Information System (INIS)

    Donald, M.H.R.; Paterson, J.M.

    1980-01-01

    When colliding electron and positron bunches in SPEAR at high values of the beam-beam tune shift parameter Δν, it had been observed that sometimes one of the equal intensity beams would blow up in the vertical plane more than the other beam. It was subsequently found that a small adjustment to the phase difference between the RF accelerating cavities would make the beam flip the other way. The results of the investigation of this phenomenon are presented in this paper

  8. Investigation of the flip-flop beam--beam effect in SPEAR

    International Nuclear Information System (INIS)

    Donald, M.H.R.; Paterson, J.M.

    1979-03-01

    When colliding electron and positron bunches in SPEAR at high values of the beam--beam tune shift parameter Δν, it had been observed that sometimes one of the equal intensity beams would blow up in the vertical plane more than the other beam. It was subsequently found that a small adjustment to the phase difference between the RF accelerating cavities would make the beam flip the other way. The results of the investigation of this phenomenon are presented in this paper

  9. Summary of Working Group I - beam-beam instability with crossing angle

    International Nuclear Information System (INIS)

    Chen, T.

    1995-06-01

    This report is a summary report from a panel addressing the problem of beam-beam instability in colliding beams at finite crossing angles. This problem arises in the process of increasing luminosity in large circular particle factories. The primary means of increasing luminosity comes down to increasing the number of bunches in each beam, while decreasing the spacing between bunches. This situation favors finite crossing angle collision schemes. However such schemes allow synchro-betatron coupling, as transverse and longitudinal energies are mixed. The authors summarize their discussions on this problem, and the present state of experience with such schemes

  10. Luminosity, Beamstrahlung energy loss and beam-beam deflections for e{sup +}e{sup -} and e{sup -}e{sup -} collisions at the ILC with 500 GeV and varying transverse beam sizes

    Energy Technology Data Exchange (ETDEWEB)

    Alabau Pons, M. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS et Universite de Paris-Sud XI, Bat. 200, B.P. 34, 91898 Orsay Cedex (France)]|[IFIC, Edificio Institutos de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Bambade, P. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS et Universite de Paris-Sud XI, Bat. 200, B.P. 34, 91898 Orsay Cedex (France); Faus-Golfe, A. [IFIC, Edificio Institutos de Paterna, Aptdo. 22085, 46071 Valencia (Spain)

    2006-01-15

    At the interaction point of the International Linear Collider, beam-beam effects due to the strong electromagnetic fields that the bunches experience during collisions cause a mutual focusing, called pinch effect, which enhances the luminosity in the case of e{sup +}e{sup -} collisions. The opposite is true for e{sup -}e{sup -} collisions. In this case the luminosity is reduced by mutual defocusing, or anti-pinching. The resulting Beamstrahlung energy loss and beam-beam deflection angles as function of the vertical transverse offset are also different for both modes of operation. The dependence of these quantities with transverse beam sizes are presented for the case of e{sup -}e{sup -} collisions.

  11. Linear beam-beam tune shift calculations for the Tevatron Collider

    International Nuclear Information System (INIS)

    Johnson, D.

    1989-01-01

    A realistic estimate of the linear beam-beam tune shift is necessary for the selection of an optimum working point in the tune diagram. Estimates of the beam-beam tune shift using the ''Round Beam Approximation'' (RBA) have over estimated the tune shift for the Tevatron. For a hadron machine with unequal lattice functions and beam sizes, an explicit calculation using the beam size at the crossings is required. Calculations for various Tevatron lattices used in Collider operation are presented. Comparisons between the RBA and the explicit calculation, for elliptical beams, are presented. This paper discusses the calculation of the linear tune shift using the program SYNCH. Selection of a working point is discussed. The magnitude of the tune shift is influenced by the choice of crossing points in the lattice as determined by the pbar ''cogging effects''. Also discussed is current cogging procedures and presents results of calculations for tune shifts at various crossing points in the lattice. Finally, a comparison of early pbar tune measurements with the present linear tune shift calculations is presented. 17 refs., 13 figs., 3 tabs

  12. Testing Long-Range Beam-Beam Compensation for the LHC Luminosity Upgrade

    CERN Document Server

    Rijoff, T L

    2012-01-01

    The performance of the Large Hadron Collider (LHC) at CERN and its minimum crossing angle are limited by the effect of long-range beam-beam collisions. A wire compensators can mitigate part of the long-range effects and may allow for smaller crossing angles, or higher beam intensity. A prototype long-range wire compensator could be installed in the LHC by 2014/15. Since the originally reserved position for such a wire compensator is not available for this first step, we explore other possible options. Our investigations consider various longitudinal and transverse locations, different wire shapes, different optics configurations and several crossing angles between the two colliding beams. Simulations are carried out with the weak-strong code BBtrack. New postprocessing tools are introduced to analyse tune footprints and particle stability. In particular, a new method for the Lyapunov coefficient calculation is implemented. Submitted as "Tesi di laurea" at the University of Milano, 2012.

  13. Computer simulation of the beam-beam interaction at a crossing angle

    International Nuclear Information System (INIS)

    Piwinski, A.

    1985-01-01

    The simulation is done for protons in HERA which was first designed with a crossing angle. Although the assumed space charge parameter is relatively small many resonances can be seen after 50000 revolutions, i.e. about 1 second of storage time. The dependence on the crossing angle and on the order of the satellite resonances is investigated

  14. Correction of beam-beam effects in luminosity measurement at ILC

    CERN Document Server

    Lukic, S

    2015-01-01

    Three methods for handling beam-beam effects in luminosity measurement at ILC are tested and evaluated in this work. The first method represents an optimization of the LEPtype asymmetric selection cuts that reduce the counting biases. The second method uses the experimentally reconstructed shape of the √ s ′ spectrum to determine the Beamstrahlung component of the bias. The last, recently proposed, collision-frame method relies on the reconstruction of the collision-frame velocity to define the selection function in the collision frame both in experiment and in theory. Thus the luminosity expression is insensitive to the difference between the CM frame of the collision and the lab frame. The collision-frame method is independent of the knowledge of the beam parameters, and it allows an accurate reconstruction of the luminosity spectrum above 80% of the nominal CM energy. However, it gives no precise infromation about luminosity below 80% of the nominal CM energy. The compatibility of diverse selection cut...

  15. Beam-Beam effects at the CMS BRIL van-der-Meer scans

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is devoted to the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS Experiment at CERN. The project is engaged in operating and developing new detectors, compatible with the high luminosity experimental environments at the LHC. BRIL operates several detectors based on different physical principles and technologies. The detectors are calibrated using van-der-Meer scans to measure the luminosity that is a fundamental quantity of the LHC beam. In van-der-Meer scans the count rate in a detector is measured as a function of the distance between beams in the plane perpendicular to beam direction, to extract the underlying beam overlap area. The goal of the van-der-Meer scans is to obtain the calibration constant for each luminometer to be used at calibration then in physics data taking runs. The note presents the overview of beam-beam effects at the van-der-Meer scan and the corresponding corrections that sh...

  16. LHC MD2877: Beam-beam long range impact on coupling measurements

    CERN Document Server

    Wenninger, Jorg; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fuchsberger, Kajetan; Hostettler, Michi; Persson, Tobias Hakan Bjorn; Tomas Garcia, Rogelio; Valuch, Daniel; Garcia-Tabares Valdivieso, Ana; CERN. Geneva. ATS Department

    2018-01-01

    The LHC is now operating with a tune separation of ∼0.004 in collision. This puts tight constraints on the allowed transverse coupling since a |C−| larger than a fraction of the fractional tune split may lead to beam instabilities. In the last years a new tool based on the ADT used in a similar way as an AC-dipole to excite the beam was developed. The ADT AC-dipole gives coherent oscillations without increasing the beam emittance. These oscillations are analyzed automatically to obtain the value of the coupling. A coupling measurement campaign was done in 2017 and while the correction converged and stayed rather constant over time it was observed that depending on the target bunch and filling scheme the results could vary by Δ|C−| ∼ 0.002. In this MD report we investigated 3 different bunches, one with Long Range Beam-Beam (LRBB) in IPs 1 and 5, one with LRBB in all IPs and one with no LRBB. The results indicate that there are differences in coupling between the bunches experiencing different LR...

  17. Compensation of head-on beam-beam induced resonance driving terms and tune spread in the Relativistic Heavy Ion Collider

    Directory of Open Access Journals (Sweden)

    W. Fischer

    2017-09-01

    Full Text Available A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC at Brookhaven National Laboratory [Phys. Rev. Lett. 115, 264801 (2015PRLTAO0031-900710.1103/PhysRevLett.115.264801]. The compensation consists of electron lenses for the reduction of the beam-beam induced tune spread, and a lattice for the minimization of beam-beam generated resonance driving terms. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

  18. Analytical treatment of the nonlinear electron cloud effect and the combined effects with beam-beam and space charge nonlinear forces in storage rings

    International Nuclear Information System (INIS)

    Gao Jie

    2009-01-01

    In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonlinear electron cloud effect combined with beam-beam and space charge effects, analytically. This analytical treatment is applied to BEPC II. The corresponding analytical expressions developed in this paper are useful both in understanding the physics behind these problems and also in making practical quick hand estimations. (author)

  19. Global compensation of long-range beam-beam effects with octupole magnets: dynamic aperture simulations for the HL-LHC case and possible usage in LHC and FCC.

    CERN Document Server

    Barranco Garcia, Javier; CERN. Geneva. ATS Department

    2017-01-01

    The Large Hadron Collider has shown with various experimental verifications that one of the main limitations to the collider performance and to a possible upgrade can come from the long-range beam-beam effects which will define the operational parameters (intensities and emittances) and machine set-up (crossing angles and the minimum beta function at the interaction points). The High Luminosity project aims at very high intensities and will therefore need much larger separations to keep the long range effects weak. In the past several studies of possible active compensators have been carried out and experimental studies are planned to explore such schemes in the LHC. In this note we show the feasibility of using octupole magnets to compensate the effects of long range beam-beam interactions by use of dynamical aperture simulations. A prove of principle of such a compensation scheme is shown for the HL-LHC optics. Preliminary studies for the LHC optics ATS and standard are also presented pointing to the import...

  20. Fast Poisson Solvers for Self-Consistent Beam-Beam and Space-Charge Field Computation in Multiparticle Tracking Simulations

    CERN Document Server

    Florio, Adrien; Pieloni, Tatiana; CERN. Geneva. ATS Department

    2015-01-01

    We present two different approaches to solve the 2-dimensional electrostatic problem with open boundary conditions to be used in fast tracking codes for beam-beam and space charge simulations in high energy accelerators. We compare a fast multipoles method with a hybrid Poisson solver based on the fast Fourier transform and finite differences in polar coordinates. We show that the latter outperforms the first in terms of execution time and precision, allowing for a reduction of the noise in the tracking simulation. Furthermore the new algorithm is shown to scale linearly on parallel architectures with shared memory. We conclude by effectively replacing the HFMM by the new Poisson solver in the COMBI code.

  1. Note on beam--beam tune shift in single ring multi bunch mode

    International Nuclear Information System (INIS)

    Month, M.

    1978-01-01

    If many identical counter-rotating bunches of protons and antiprotons are stored in a single ring, they will have identical orbits. The question is: Is this total tune shift relevant to the problem of beam stability. The answer is: not in general. The nonlinear force is described by its ''strength'', Δν/sub I/, for each bunch interaction individually. It is not at all clear that the sum of the individual Δν/sub I/ is the significant quantity

  2. Beam-beam effects in high energy e+e- storage rings: resonant amplification of vertical dimensions for flat beams

    International Nuclear Information System (INIS)

    Bambade, P.

    1984-06-01

    In this thesis, we present a phenomenological study of the beam-beam effect in e + e - storage rings. We are in particular interested in the blow-up of the vertical dimension observed in this kind of accelerator. A detailed analysis of the electromagnetic field generated by the very flat bunches stored, and seen by the counter-rotating particles shows that two-dimensional non-linear resonances, which couple vertical and horizontal betatron oscillations, play a very important role. Moreover, the ''weak beam-strong beam'' approximation holds rather well in the case of very flat bunches. Perturbative analysis enables us to predict the effects from the strongest coupling resonance: 20sub(x)-20sub(y) = integer. We find that mainly the tails of the vertical distribution are affected, and we give a criterion concerning the optimal distance to this resonance in the case of a storage ring such as LEP. Finally, the results and in particular the validity of the single resonance approximation are checked through a numerical simulation [fr

  3. Suppression of emittance growth caused by mechanical vibrations of magnetic elements in presence of beam-beam effects in the SSC

    International Nuclear Information System (INIS)

    Lebedev, V.A.; Parkhomchuk, V.V.; Shil'tsev, V.D.; Skrinskij, A.N.

    1991-01-01

    A ground motion produces shifts of storage ring quadrupoles. It strongly influences on the beam behaviour in large proton (anti)proton colliders due to the closed orbit distortion and due to the transverse emittance growth. Calculations of both effects are presented in this paper. An active feedback system is useful for the emittance growth suppression. It is shown that in this case the main parameter which determines the emittance growth is the betatron tune spread due to the beam-beam effects. A simple analytical model is considered which results are in good coincidence with computer simulations. All calculations are adapted to the Superconducting Super Collider (SSC). 13 refs.; 9 figs.; 3 tabs

  4. Nonlinear interaction of colliding beams in particle storage rings

    International Nuclear Information System (INIS)

    Herrera, J.C.; Month, M.

    1979-01-01

    When two beams of high energy particles moving in opposite directions are brought into collision, a large amount of energy is available for the production of new particles. However to obtain a sufficiently high event rate for rare processes, such as the production of the intermediate vector boson (Z 0 and W +- ), large beam currents are also required. Under this circumstance, the high charge density of one beam results in a classical electromagnetic interaction on the particles in the other beam. This very nonlinear space charge force, caled the beam-beam force, limits the total circulating charge and, thereby, the ultimate performance of the colliding ring system. The basic nature of the beam-beam force is discussed, indicating how it is quite different in the case of continuous beams, which cross each other at an angle as compared to the case of bunched beams which collide head-on. Some experimental observations on the beam-beam interaction in proton-proton and electron-positron beams are then reviewed and interpreted. An important aspect of the beam-beam problem in storage rings is to determine at what point in the analysis of the particle dynamics is it relevant to bring in the concepts of stochasticity, slow diffusion, and resonance overlap. These ideas are briefly discussed

  5. Simulation of the Beam-Beam Effects in e+e- Storage Rings with a Method of Reducing the Region of Mesh

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yunhai

    2000-08-31

    A highly accurate self-consistent particle code to simulate the beam-beam collision in e{sup +}e{sup -} storage rings has been developed. It adopts a method of solving the Poisson equation with an open boundary. The method consists of two steps: assigning the potential on a finite boundary using the Green's function, and then solving the potential inside the boundary with a fast Poisson solver. Since the solution of the Poisson's equation is unique, the authors solution is exactly the same as the one obtained by simply using the Green's function. The method allows us to select much smaller region of mesh and therefore increase the resolution of the solver. The better resolution makes more accurate the calculation of the dynamics in the core of the beams. The luminosity simulated with this method agrees quantitatively with the measurement for the PEP-II B-factory ring in the linear and nonlinear beam current regimes, demonstrating its predictive capability in detail.

  6. Overview of design development of FCC-hh Experimental Interaction Regions

    CERN Document Server

    AUTHOR|(CDS)2082479; Abelleira, Jose; Cruz Alaniz, Emilia; Van Riesen-Haupt, Leon; Benedikt, Michael; Besana, Maria Ilaria; Buffat, Xavier; Burkhardt, Helmut; Cerutti, Francesco; Langner, Andy Sven; Martin, Roman; Riegler, Werner; Schulte, Daniel; Tomas Garcia, Rogelio; Appleby, Robert Barrie; Rafique, Haroon; Barranco Garcia, Javier; Pieloni, Tatiana; Boscolo, Manuela; Collamati, Francesco; Nevay, Laurence James; Hofer, Michael

    2017-01-01

    The experimental interaction region (EIR) is one of the key areas that define the performance of the Future Circular Collider. In this overview we will describe the status and the evolution of the design of EIR of FCC-hh, focusing on design of the optics, energy deposition in EIR elements, beam-beam effects and machine detector interface issues.

  7. Automatic beam centering at the SSC interaction regions

    International Nuclear Information System (INIS)

    Joestlein, H.

    1984-01-01

    In the SSC interaction regions, the two colliding beams, each only a few microns in size, will have to be centered and maintained in good alignment over many hours, in order to provide the maximum possible luminosity and to minimize off-center beam-beam focussing effects. It is unlikely that sufficiently good alignment can be achieved without some kind of active feedback system, based on the beam-beam interaction rate. This memo describes such a system. In the proposed scheme, one of the beams is moved continuously and in a circular fashion about its mean transverse position. The radius of this motion is approximately 0.01 of the rms beam size at the interaction point. The motion is achieved with two sets of crossed high frequency dipole magnets, one on each side of the interaction region, suitably phased. As a consequence of this motion, the beam-beam interaction rate is modulated in synchronism with the beam motion when the beams are not centered on one another. The amplitude and phase of this modulation yields information on the magnitude and direction of the misalignment between the beams, allowing continuous display and automatic correction of any misalignment

  8. Photon production at the interaction point of the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Appleby, R. [Manchester Univ., Cockcroft Institute and the University of Oxford Road, Manchester (United Kingdom); Bambade, P. [Univ Paris-Sud, LAL, CNRS/IN2P3, 91 - Orsay (France)

    2008-01-15

    The intense beam-beam effect at the interaction point of the International Linear Collider (ILC) causes large disruption of the beams and the production of photons. These photons, arising dominantly through Beamstrahlung emission, are problematic for the machine design as they need to be transported and dumped in a controlled way. In this work, we perform simulations of the beam-beam interaction to predict photon production rates and distributions for the different beam parameters considered at ILC. The results are expressed in terms of a set of cones of excluded power, allowing to define the beam-stay-clear requirements relevant for different cases and contexts. A comparison is also made with theoretical expectations. The suggested photon cone half-opening angles are 0.75 and 0.85 mrad in the horizontal and vertical planes, respectively. These cones cover all machine energies and parameter sets, and include the low power Compton photons. (authors)

  9. Optimization of the Phase Advance Between RHIC Interaction Points

    CERN Document Server

    Tomas, Rogelio

    2005-01-01

    We consider the scenario of having two identical Interaction Points (IPs) in the Relativistic Heavy Ion Collider (RHIC). The strengths of beam-beam resonances strongly depend on the phase advance between these two IPs and therefore certain phase advances could improve beam lifetime and luminosity. We compute the dynamic aperture as function of the phase advance between these IPs to find the optimum settings. The beam-beam interaction is treated in the weak-strong approximation and a complete non-linear model of the lattice is used. For the current RHIC proton working point (0.69,0.685) the design lattice is found to have the optimum phase advance. However this is not the case for other working points.

  10. The effect of phase advance errors between interaction points on beam halos

    International Nuclear Information System (INIS)

    Chen, T.; Irwin, J.; Siemann, R.H.

    1995-01-01

    Phase advance errors between interaction points (IP) break the symmetry of multi-IP colliders. This symmetry breaking introduces new, lower order resonances which may chance the halo from the beam-beam interaction dramatically. In this paper, the mechanism of introducing new resonances is discussed. Simulation results showing the changes due to phase advance errors are presented. Simulation results are compared with experimental measurements at VEPP-2M

  11. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions ...

  12. International workshop on final focus and interaction regions of next generation linear colliders: Proceedings

    International Nuclear Information System (INIS)

    1992-01-01

    The first day of the workshop was devoted to four plenary ''issues'' talks, one for each working group: Beam-Beam Interaction, Detector, Hardware, and Optical Design. The last day was devoted to plenary talks summarizing the activities of the working groups. Each of the three remaining days there,was a short morning plenary devoted to a brief summary of the preceding day and an announcement of planned working group discussions for that day. The transparencies for the ''issues'' and ''summary'' talks are included in this volume, along with some remarks from the working group chairpersons. Very briefly, the beam-beam group continued to address the quantitative study of QED induced backgrounds, and attempted to better understand the nature and prevalence of QCD millijets. The detector group attempted to identify the impact on masking and detector design of the beam-beam backgrounds, the synchrotron radiation induced backgrounds from beam halos and muon backgrounds produced primarily in collimators. Nanosecond timing elements needed in conjunction with multi-bunch operation were discussed. The hardware group addressed the problem of magnet design and support, especially the final doublet magnets suspended within the detector environment, and instrumentation issues, such as high resolution beam position monitors. The optics group discussed new final focus system ideas, collimator design, and improvement of beamline tolerances. If you were not here to participate, we hope that this volume will help you in your orientation to these problems

  13. Interaction Region Design for a Ring-Ring LHeC

    CERN Document Server

    Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

    2011-01-01

    tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

  14. THE DAΦNE INTERACTION REGION FOR THE KLOE-2 RUN

    CERN Document Server

    Milardi, Catia; Raimondi, Pantaleo

    2010-01-01

    Recently a new collision scheme based on large Piwinski angle and Crab-Waist compensation of the beam-beam interaction has been proposed and implemented on DAΦNE. The new configuration has been used to provide beam-beam events to the SIDDHARTA experiment, a compact device without solenoidal field, heir of DEAR, providing a simple environment for the Crab-Waist test. The luminosity has been increased by a factor 3 with a peak value of 4.53x1032 cm-2s-1 letting in collision currents slightly lower than those corresponding to the old records. The highest daily integrated luminosity measured in a moderate injection regime, suitable for SIDDHARTA operation, has been L∫day ~15 pb-1. An almost continuous injection regime provided L∫1 hour ~1.0 pb-1 hourly integrated luminosity which opened significant perspectives for the KLOE-2 experiment. Scaling this best integrated luminosity measured over two hours, it is reasonable to expect more than 20 pb-1 per day, and assuming 80% collider uptime as during the past ru...

  15. Limitations of interaction-point spot-size tuning at the SLC

    International Nuclear Information System (INIS)

    Emma, P.; Hendrickson, L.J.; Zimmermann, F.; Raimondi, P.

    1997-05-01

    At the Stanford Linear Collider (SLC), the interaction-point spot size is minimized by repeatedly correcting, for both beams, various low-order optical aberrations, such as dispersion, waist position or coupling. These corrections are performed about every 8 hours, by minimizing the IP spot size while exciting different orthogonal combinations of final-focus magnets. The spot size itself is determined by measuring the beam deflection angle as a function of the beam-beam separation. Additional information is derived from the energy loss due to beamstrahlung and from luminosity-related signals. In the 1996 SLC run, the typical corrections were so large as to imply a 20-40% average luminosity loss due to residual uncompensated or fluctuating tunable aberrations. In this paper, the authors explore the origin of these large tuning corrections and study possible mitigations for the next SLC run

  16. Interactively exploring optimized treatment plans

    International Nuclear Information System (INIS)

    Rosen, Isaac; Liu, H. Helen; Childress, Nathan; Liao Zhongxing

    2005-01-01

    Purpose: A new paradigm for treatment planning is proposed that embodies the concept of interactively exploring the space of optimized plans. In this approach, treatment planning ignores the details of individual plans and instead presents the physician with clinical summaries of sets of solutions to well-defined clinical goals in which every solution has been optimized in advance by computer algorithms. Methods and materials: Before interactive planning, sets of optimized plans are created for a variety of treatment delivery options and critical structure dose-volume constraints. Then, the dose-volume parameters of the optimized plans are fit to linear functions. These linear functions are used to show in real time how the target dose-volume histogram (DVH) changes as the DVHs of the critical structures are changed interactively. A bitmap of the space of optimized plans is used to restrict the feasible solutions. The physician selects the critical structure dose-volume constraints that give the desired dose to the planning target volume (PTV) and then those constraints are used to create the corresponding optimized plan. Results: The method is demonstrated using prototype software, Treatment Plan Explorer (TPEx), and a clinical example of a patient with a tumor in the right lung. For this example, the delivery options included 4 open beams, 12 open beams, 4 wedged beams, and 12 wedged beams. Beam directions and relative weights were optimized for a range of critical structure dose-volume constraints for the lungs and esophagus. Cord dose was restricted to 45 Gy. Using the interactive interface, the physician explored how the tumor dose changed as critical structure dose-volume constraints were tightened or relaxed and selected the best compromise for each delivery option. The corresponding treatment plans were calculated and compared with the linear parameterization presented to the physician in TPEx. The linear fits were best for the maximum PTV dose and worst

  17. Strong field QED in lepton colliders and electron/laser interactions

    Science.gov (United States)

    Hartin, Anthony

    2018-05-01

    The studies of strong field particle physics processes in electron/laser interactions and lepton collider interaction points (IPs) are reviewed. These processes are defined by the high intensity of the electromagnetic fields involved and the need to take them into account as fully as possible. Thus, the main theoretical framework considered is the Furry interaction picture within intense field quantum field theory. In this framework, the influence of a background electromagnetic field in the Lagrangian is calculated nonperturbatively, involving exact solutions for quantized charged particles in the background field. These “dressed” particles go on to interact perturbatively with other particles, enabling the background field to play both macroscopic and microscopic roles. Macroscopically, the background field starts to polarize the vacuum, in effect rendering it a dispersive medium. Particles encountering this dispersive vacuum obtain a lifetime, either radiating or decaying into pair particles at a rate dependent on the intensity of the background field. In fact, the intensity of the background field enters into the coupling constant of the strong field quantum electrodynamic Lagrangian, influencing all particle processes. A number of new phenomena occur. Particles gain an intensity-dependent rest mass shift that accounts for their presence in the dispersive vacuum. Multi-photon events involving more than one external field photon occur at each vertex. Higher order processes which exchange a virtual strong field particle resonate via the lifetimes of the unstable strong field states. Two main arenas of strong field physics are reviewed; those occurring in relativistic electron interactions with intense laser beams, and those occurring in the beam-beam physics at the interaction point of colliders. This review outlines the theory, describes its significant novel phenomenology and details the experimental schema required to detect strong field effects and the

  18. Instrumental interaction

    OpenAIRE

    Luciani , Annie

    2007-01-01

    International audience; The expression instrumental interaction as been introduced by Claude Cadoz to identify a human-object interaction during which a human manipulates a physical object - an instrument - in order to perform a manual task. Classical examples of instrumental interaction are all the professional manual tasks: playing violin, cutting fabrics by hand, moulding a paste, etc.... Instrumental interaction differs from other types of interaction (called symbolic or iconic interactio...

  19. 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

  20. Intermolecular interactions

    International Nuclear Information System (INIS)

    Kaplan, I.G.; Rodimova, O.B.; AN SSSR, Tomsk. Inst. Optiki Atmosfery)

    1978-01-01

    The present state of the intermolecular interaction theory is described. The general physical picture of the molecular interactions is given, the relative contributions of interactions of different types are analyzed (electrostatic, resonance, induction, dispersion, relativistic, magnetostatic and exchange), and the main ones in each range of separations are picked out. The methods of the potential curve calculations are considered, specific for definite separations between the interacting systems. The special attention is paid to the analysis of approximations used in different theoretical calculation methods

  1. Effective interactions

    International Nuclear Information System (INIS)

    Elliott, J.P.

    1981-01-01

    This chapter attempts to describe and compare some of the more important nucleon-nucleon interactions that have been used in nuclear structure calculations, and to relate them where possible to the real nucleon-nucleon interaction. Explains that different interactions have been used depending on whether one is fitting to total binding energies and densities with a Hartree Fock (HF) calculation or fitting to spectra and spectroscopic data in a shell model calculation. Examines both types of calculation after two preliminary sections concerned with notation and with the philosophy underlying the use of model spaces and effective interactions. Discusses Skyrme interactions, finite range interactions, small model space, large model space, and the Sussex potential matrix elements. Focuses on the more empirical approaches in which a simple form is chosen for the effective interaction in a given model space and the parameters are deduced from fitting many-body data

  2. 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

  3. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  4. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

  5. Aesthetic interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Iversen, Ole Sejer; Krogh, Peter

    2004-01-01

    , as it promotes aesthetics of use, rather than aesthetics of appearance. We coin this approach in the perspective of aesthetic interaction. Finally we make the point that aesthetics is not re-defining everything known about interactive systems. We provide a framework placing this perspective among other...

  6. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  7. Explicit Interaction

    DEFF Research Database (Denmark)

    Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per

    2006-01-01

    We report an ongoing study of palpable computing to support surgical rehabilitation, in the general field of interaction design for ubiquitous computing. Through explorative design, fieldwork and participatory design techniques, we explore the design principle of explicit interaction as an interp...

  8. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... practical examples of designing for bodily potential. This paper presents Kinesthetic Interaction as a unifying concept for describing the body in motion as a foundation for designing interactive systems. Based on the theoretical foundation for Kinesthetic Interaction, a conceptual framework is introduced...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is a tool...

  9. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  10. Interaction graphs

    DEFF Research Database (Denmark)

    Seiller, Thomas

    2016-01-01

    Interaction graphs were introduced as a general, uniform, construction of dynamic models of linear logic, encompassing all Geometry of Interaction (GoI) constructions introduced so far. This series of work was inspired from Girard's hyperfinite GoI, and develops a quantitative approach that should...... be understood as a dynamic version of weighted relational models. Until now, the interaction graphs framework has been shown to deal with exponentials for the constrained system ELL (Elementary Linear Logic) while keeping its quantitative aspect. Adapting older constructions by Girard, one can clearly define...... "full" exponentials, but at the cost of these quantitative features. We show here that allowing interpretations of proofs to use continuous (yet finite in a measure-theoretic sense) sets of states, as opposed to earlier Interaction Graphs constructions were these sets of states were discrete (and finite...

  11. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi

    2015-01-01

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...

  12. Diffractive interactions

    International Nuclear Information System (INIS)

    Del Duca, V.; Marage, P.

    1996-08-01

    The general framework of diffractive deep inelastic scattering is introduced and reports given in the session on diffractive interactions at the international workshop on deep-inelastic scattering and related phenomena, Rome, April 1996, are presented. (orig.)

  13. Interaction Widget

    DEFF Research Database (Denmark)

    Ingstrup, Mads

    2003-01-01

    This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced...... in the pattern. The intended audience of the pattern is developers and researchers within the field of human computer interaction....

  14. Hair Interactions

    OpenAIRE

    Cani , Marie-Paule; Bertails , Florence

    2006-01-01

    International audience; Processing interactions is one of the main challenges in hair animation. Indeed, in addition to the collisions with the body, an extremely large number of contacts with high friction rates are permanently taking place between individual hair strands. Simulating the latter is essential: without hair self-interactions, strands would cross each other during motion or come to rest at the same location, yielding unrealistic behavior and a visible lack of hair volume. This c...

  15. MD 400: LHC emittance growth in presence of an external source of noise during collision

    CERN Document Server

    Barranco Garcia, Javier; Pieloni, Tatiana; Tambasco, Claudia; Trad, Georges; Valuch, Daniel; Betz, Michael; Wendt, Manfred; Pojer, Mirko; Solfaroli Camillocci, Matteo; Salvachua Ferrando, Belen Maria; Fuchsberger, Kajetan; Albert, Markus; Qiang, Ji; CERN. Geneva. ATS Department

    2016-01-01

    The interplay between head-on beam-beam interaction and external sources of noise can be a significant source of emittance growth, especially when considering large beam-beam tune shifts as for the HL-LHC upgrade project. In this experiment the emittance growth of colliding bunches with different brightness and therefore different beam-beam parameters in the presence of an external white noise source with different amplitudes is measured for different gains of the transverse feedback.

  16. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments......, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors also...

  17. Multiquark interactions

    International Nuclear Information System (INIS)

    Luk'yanov, V.K.

    1984-01-01

    To study multiquark interactions (MQI) the data of experiments confirming the presence of 3q, 6q, 12q states in interacting nuclear nucleons, in hadron- and lepton-nuclear processes at high energies and high momentum transfers are considered. Experimental data on cumulative processes pointing to the existence of MQI are analyzed. Two-channel model of a nucleus (the model of interacting nucleons) in the theory of coupled channels is discussed. The behaviour of form factor of deuteron and NQI (6q) contributions to ed scattering as well as deep inelastic scattering on nuclei are studied. The data known as EMC effect are discussed. It is pointed out that introduction of the notion MQI and consideration of a nucleus as a system of nucleons with a low MQI addition will help to explain such processes as cumulative reactions, form factors of a deuteron and light nuclei, deep inelastic scattering on nuclei

  18. Interaction region

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The Interaction Region Group addressed the basic questions of how to collide the SLC beams, how to maximize and monitor the luminosity, and how to minimize the detector backgrounds at the interaction region. In practice, five subgroups evolved to study these questions. The final focus group provided three alternative designs to acheive the 1 to 2 micron beam spot size required by the SLC, as well as studying other problems including: eta, eta' matching from the collider arcs, the implementation of soft bends near the interaction region, beam emittance growth, and magnet tolerances in the final focus. The beam position monitor group proposed two devices, a strip line monitor, and a beamstrahlung monitor, to bring the beams into collision. The luminosity monitor group reviewed the possible QED processes that would be insensitive to weak interaction (Z 0 ) effects. The beam dumping group proposed locations for kicker and septum magnets in the final focus that would achieve a high dumping efficiency and would meet the desired beam tolerances at the Moller scattering target in the beam dump line. Working with the Polarization Group, the Moller experiment was designed into the beam dump beam line. A beam dump was proposed that would maintain radiation backgrounds (penetrating muons) at acceptible levels. The detector backgrounds group proposed soft-bend and masking configurations to shield the detector from synchrotron radiation from the hard/soft bends and from the final focus quadrupoles and evaluated the effectiveness of these designs for the three final focus optics designs. Backgrounds were also estimated from: large angle synchrotron radiation, local and distant beam-gas interactions, 2-photon interactions, and from neutrons and backscattered photons from the beamstrahlung dump

  19. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  20. Interacting binaries

    International Nuclear Information System (INIS)

    Eggleton, P.P.; Pringle, J.E.

    1985-01-01

    This volume contains 15 review articles in the field of binary stars. The subjects reviewed span considerably, from the shortest period of interacting binaries to the longest, symbiotic stars. Also included are articles on Algols, X-ray binaries and Wolf-Rayet stars (single and binary). Contents: Preface. List of Participants. Activity of Contact Binary Systems. Wolf-Rayet Stars and Binarity. Symbiotic Stars. Massive X-ray Binaries. Stars that go Hump in the Night: The SU UMa Stars. Interacting Binaries - Summing Up

  1. Hadron interactions

    International Nuclear Information System (INIS)

    Fischer, J.; Kolar, P.; Kundrat, V.

    1988-01-01

    The proceedings contain invited lectures and papers presente at the symposium. Attention was devoted to hadron interactions a high energy in QCD, to the structure and decay of hadrons, the production of hadrons and supersymmetric particles in e + e - and ep collisions, to perturbation theory in quantum field theory, and new supersymmetric extensions of relativistic algebra. (Z.J

  2. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions, an...

  3. Experimental study of the molecular beam destruction by beam-beam and beam-background scattering

    International Nuclear Information System (INIS)

    Bossel, U.; Dettleff, G.

    1974-01-01

    The extraction of flow properties related to the molecular motion normal to stream lines of an expanding gas jet from observed intensity profiles of supersonic beams is critically assessed. The perturbation of the profile curves by various effects is studied for a helium beam. Exponential laws appear to describe scattering effects to a satisfactory degree

  4. Effects of beam-beam collisions on storage-ring performance - a pedagogical review

    International Nuclear Information System (INIS)

    Schonfeld, J.F.

    1983-01-01

    This paper presents a survey of the experimental and theoretical literature on colliding-beam effects in both leptonic and hadronic storage rings. For the most part, this literature is rather technical and, to the novice, both obscurely written and hard to locate. Although there have already been several symposia on the subject, as well as a number of reviews for specialists there has up till now been no unified and pedagogical exposition. The present work represents an attempt to fill this gap. The material is grouped into four major areas: observational phenomenology, computer simulation, mathematical background, and theoretical models. 113 references, 36 figures

  5. Study of periodic tune modulation with the beam-beam effect

    International Nuclear Information System (INIS)

    Neuffer, D.; Riddiford, A.; Ruggerio, A.G.

    1983-01-01

    Simulations of weak-strong pp - collisions with a periodic tune modulation show the possiblity of beam blowup at sufficiently strong modulation amplitudes. This beam blowup is associated with the appearance of nonrepeatable ''chaotic'' trajectories and occurs when low order resonances are crossed by the modulation. In this paper the authors report results of an investigation of the dependence of this blowup upon the modulation frequency, with the modulation amplitude fixed. It is determined that if a threshold frequency exists, modulations at frequencies greater than the threshold do not lead to beam blowup

  6. Advances in intense beams, beam delivery, targetry, and radiochemistry at advanced cyclotron systems

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.R. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada)]. E-mail: djohnson@advancedcyclotron.com; Watt, R. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Kovac, B. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Zyuzin, A. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Van Lier, E. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Erdman, K.L. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Gyles, Wm. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); Sabaiduc, V. [Advanced Cyclotron Systems Inc., 7851 Alderbridge Way, Richmond, BC, V6X 2A4 (Canada); McQuarrie, S.A. [Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Wilson, J. [Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Backhouse, C. [Department of Electrical Engineering, University of Alberta, Edmonton, AB (Canada); Gelbart, Wm. [Advanced System Design, C22, S6, RR1, Garden Bay, BC, V0N 1S0 (Canada); Kuo, T. [4654 N. Larwin Ave., Concorde, CA 94521 United States (United States)

    2007-08-15

    The increasing demand for radionuclides for PET and SPECT has resulted in ACSI system improvements starting from the cyclotron and proceeding to the Radiochemistry Modules. With more TR30 cyclotrons installed and operating at full capacity, emphasis has been placed on improving the operational components to reduce both the incidence of failure and subsequent maintenance time. A cyclotron system has been developed that meets the needs of a regional radiopharmacy that supplies both positron and single photon emitters that would not otherwise be available. This new system has been named the TR24. In order to deal with some of the challenges of high currents, a method has been developed for passivating the entrance window foil during high current irradiation of a water target used to produce F-18. A method has been developed for passivating the entrance window foil to reduce unwanted chemical species that interfere with radiopharmaceutical production. Preliminary results for novel radioiodine production technique using the TR19/9 are also discussed.

  7. Advances in intense beams, beam delivery, targetry, and radiochemistry at advanced cyclotron systems

    Science.gov (United States)

    Johnson, R. R.; Watt, R.; Kovac, B.; Zyuzin, A.; Van Lier, E.; Erdman, K. L.; Gyles, Wm.; Sabaiduc, V.; McQuarrie, S. A.; Wilson, J.; Backhouse, C.; Gelbart, Wm.; Kuo, T.

    2007-08-01

    The increasing demand for radionuclides for PET and SPECT has resulted in ACSI system improvements starting from the cyclotron and proceeding to the Radiochemistry Modules. With more TR30 cyclotrons installed and operating at full capacity, emphasis has been placed on improving the operational components to reduce both the incidence of failure and subsequent maintenance time. A cyclotron system has been developed that meets the needs of a regional radiopharmacy that supplies both positron and single photon emitters that would not otherwise be available. This new system has been named the TR24. In order to deal with some of the challenges of high currents, a method has been developed for passivating the entrance window foil during high current irradiation of a water target used to produce F-18. A method has been developed for passivating the entrance window foil to reduce unwanted chemical species that interfere with radiopharmaceutical production. Preliminary results for novel radioiodine production technique using the TR19/9 are also discussed.

  8. Advances in intense beams, beam delivery, targetry, and radiochemistry at advanced cyclotron systems

    International Nuclear Information System (INIS)

    Johnson, R.R.; Watt, R.; Kovac, B.; Zyuzin, A.; Van Lier, E.; Erdman, K.L.; Gyles, Wm.; Sabaiduc, V.; McQuarrie, S.A.; Wilson, J.; Backhouse, C.; Gelbart, Wm.; Kuo, T.

    2007-01-01

    The increasing demand for radionuclides for PET and SPECT has resulted in ACSI system improvements starting from the cyclotron and proceeding to the Radiochemistry Modules. With more TR30 cyclotrons installed and operating at full capacity, emphasis has been placed on improving the operational components to reduce both the incidence of failure and subsequent maintenance time. A cyclotron system has been developed that meets the needs of a regional radiopharmacy that supplies both positron and single photon emitters that would not otherwise be available. This new system has been named the TR24. In order to deal with some of the challenges of high currents, a method has been developed for passivating the entrance window foil during high current irradiation of a water target used to produce F-18. A method has been developed for passivating the entrance window foil to reduce unwanted chemical species that interfere with radiopharmaceutical production. Preliminary results for novel radioiodine production technique using the TR19/9 are also discussed

  9. Time-dependent field equations for paraxial relativistic electron beams: Beam Research Program

    International Nuclear Information System (INIS)

    Sharp, W.M.; Yu, S.S.; Lee, E.P.

    1987-01-01

    A simplified set of field equations for a paraxial relativistic electron beam is presented. These equations for the beam electrostatic potential phi and pinch potential Phi identical to A/sub z/ - phi retain previously neglected time-dependent terms and for axisymmetric beams reduce exactly to Maxwell's equations

  10. Luminosity Loss due to Beam Distortion and the Beam-Beam Instability

    CERN Document Server

    Wu, Juhao; Raubenheimer, Tor O; Seryi, Andrei; Sramek, Christopher K

    2005-01-01

    In a linear collider, sources of emittance dilution such as transverse wakefields or dispersive errors will couple the vertical phase space to the longitudinal position within the beam (the so-called ‘banana effect'). When the Intersection Point (IP) disruption parameter is large, these beam distortions will be amplified by a single bunch kink instability which will lead to luminosity loss. We study this phenomena both analytically using linear theory and via numerical simulation. In particular, we examine the dependence of the luminosity loss on the wavelength of the beam distortions and the disruption parameter. This analysis may prove useful when optimizing the vertical disruption parameter for luminosity operation with given beam distortions.

  11. Nonlinear coherent beam-beam oscillations in the rigid bunch model

    International Nuclear Information System (INIS)

    Dikansky, N.; Pestrikov, D.

    1990-01-01

    Within the framework of the rigid bunch model coherent oscillations of strong-strong colliding bunches are described by equations which are specific for the weak-strong beam case. In this paper some predictions of the model for properties of nonlinear coherent oscillations as well as for associated limitations of the luminosity are discussed. 14 refs.; 6 figs

  12. Interactive cinema : engagement and interaction

    NARCIS (Netherlands)

    Vosmeer, M.; Schouten, B.; Mitchell, A.

    2014-01-01

    Technologies that were initially developed to be applied within the domain of video games are currently being used in experiments to explore their meaning and possibilities for cinema and cinema audiences. In this position paper we examine how narrativity, interactivity and engagement are mutually

  13. Interactive Macroeconomics

    Science.gov (United States)

    Di Guilmi, Corrado; Gallegati, Mauro; Landini, Simone

    2017-04-01

    Preface; List of tables; List of figures, 1. Introduction; Part I. Methodological Notes and Tools: 2. The state space notion; 3. The master equation; Part II. Applications to HIA Based Models: 4. Financial fragility and macroeconomic dynamics I: heterogeneity and interaction; 5. Financial fragility and macroeconomic Dynamics II: learning; Part III. Conclusions: 6. Conclusive remarks; Part IV. Appendices and Complements: Appendix A: Complements to Chapter 3; Appendix B: Solving the ME to solve the ABM; Appendix C: Specifying transition rates; Index.

  14. Interactive Governance

    DEFF Research Database (Denmark)

    Bang, Henrik

    2016-01-01

    Governance analysis has exploded in recent years, and it has become nearly impossible to tell what difference the concept and practice of governance makes from those of government and state. In addition governance analysis has been placed more and more in the shadow of the new institutionalisms and...... and growth. However, interactive governance is not a property or effect of institutions; nor does it apply solely to those individuals who seek success above everything else. It is connective more than individualistic or collectivistic in nature; and it manifests a governability capacity which...

  15. Collocated Interaction

    DEFF Research Database (Denmark)

    E. Fischer, Joel; Porcheron, Martin; Lucero, Andrés

    2016-01-01

    interactions. Yet, new challenges abound as people wear and carry more devices than ever, creating fragmented device ecologies at work, and changing the ways we socialise with each other. In this workshop we seek to start a dialogue to look back as well as forward, review best practices, discuss and design......In the 25 years since Ellis, Gibbs, and Rein proposed the time-space taxonomy, research in the ‘same time, same place’ quadrant has diversified, perhaps even fragmented. This one-day workshop will bring together researchers with diverse, yet convergent interests in tabletop, surface, mobile...

  16. 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

  17. Strong interactions

    International Nuclear Information System (INIS)

    Froissart, Marcel

    1976-01-01

    Strong interactions are introduced by their more obvious aspect: nuclear forces. In hadron family, the nucleon octet, OMEGA - decuplet, and quark triply are successively considered. Pion wave having been put at the origin of nuclear forces, low energy phenomena are described, the force being explained as an exchange of structure corresponding to a Regge trajectory in a variable rotating state instead of the exchange of a well defined particle. At high energies the concepts of pomeron, parton and stratons are introduced, pionization and fragmentation are briefly differentiated [fr

  18. Interactive Workspaces

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst

    augmented reality, interactive building elements, and mobile devices to support new ways of working in a diversity of application domains with work situations ranging from individual work, through local collaboration, to distributed collaboration. The work situations may take place in offices/project rooms......Many application domains such as architecture, engineering, industrial design, city planning, environmental supervision, health care etc. share the properties of users working collaboratively with complex mixtures of physical and digital materials. Studies in such domains show that it is hard...... to maintain and integrate these heterogeneous materials in traditional desktop computing environments. Our thesis is that pervasive computing technologies can be developed to support a more natural user collaboration in a rich variety of application. This may be achieved by going beyond the traditional...

  19. Electromagnetic interactions

    International Nuclear Information System (INIS)

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  20. Electroweak interactions

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1980-10-01

    A point of view of the electroweak interaction is presented. It begins phenomenologically and moves in stages toward the conventional gauge theory formalism containing elementary scalar Higgs-fields and then beyond. The purpose in so doing is that the success of the standard SU(2) x U(1) theory in accounting for low energy phenomena need not automatically imply success at high energies. It is deemed unlikely by most theorists that the predicted W +- or Z 0 does not exist or does not have the mass and/or couplings anticipated in the standard model. However, the odds that the standard predictions will work are not 100%. Therefore there is some reason to look at the subject as one would were he forced by a wrong experimental outcome - to go back to fundamentals and ascertain what is the minimal amount of theory necessary to account for the data

  1. Designing "Interaction": How Do Interaction Design Students Address Interaction?

    Science.gov (United States)

    Karlgren, Klas; Ramberg, Robert; Artman, Henrik

    2016-01-01

    Interaction design is usually described as being concerned with interactions with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for interaction design as interactions can be elusive…

  2. Drug Interaction API

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Interaction API is a web service for accessing drug-drug interactions. No license is needed to use the Interaction API. Currently, the API uses DrugBank for its...

  3. Designing for mobile interaction

    DEFF Research Database (Denmark)

    Nazzi, Elena

    2009-01-01

    The theme of this PhD project is designing for mobile interaction with devices and services, for the accessing, making, and sharing of information, taking into account the dynamic physical and social settings that embrace this interaction. To narrow down this theme, the whole project focuses...... on the exploitation of social interaction --- in particular among senior citizens --- to enhance and support mobile interaction....

  4. Interaction for visualization

    CERN Document Server

    Tominski, Christian

    2015-01-01

    Visualization has become a valuable means for data exploration and analysis. Interactive visualization combines expressive graphical representations and effective user interaction. Although interaction is an important component of visualization approaches, much of the visualization literature tends to pay more attention to the graphical representation than to interaction.The goal of this work is to strengthen the interaction side of visualization. Based on a brief review of general aspects of interaction, we develop an interaction-oriented view on visualization. This view comprises five key as

  5. Designing for Interactional Empowerment

    OpenAIRE

    Ståhl, Anna

    2014-01-01

    This thesis further defines how to reach Interactional Empowerment through design for users. Interactional Empowerment is an interaction design program within the general area of affective interaction, focusing on the users’ abil­ity to reflect, express themselves and engage in profound meaning-making. This has been explored through design of three systems eMoto, Affective Di­ary and Affective Health, which all mirror users’ emotions or bodily reactions in interaction in some way. From these ...

  6. Interactive pinball business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune Klok

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...... with hypotheses and experiment with scenarios as a way of innovating their business models, and why this is so...... to offer. This paper compares 'tangible business models' in the form of pinball-like contraptions, designed by interaction design students with those developed by groups of professionals around concrete business issues. We will show how the interactive models encourage business people to play...

  7. Interacting dark sector with transversal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, Luis P.; Richarte, Martín G. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Pabellón I, Buenos Aires 1428 (Argentina)

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  8. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  9. The interactive microbial ocean

    NARCIS (Netherlands)

    Brussaard, C.P.D.; Bidle, K.D.; Pedrós-Alió, C.; Legrand, C.

    2016-01-01

    Marine microorganisms inhabit diverse environments and interact over different spatial and temporal scales. To fully understand how these interactions shape genome structures, cellular responses, lifestyles, community ecology and biogeochemical cycles, integration of diverse approaches and data is

  10. Health Data Interactive (HDI)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Health Data Interactive (HDI) presents a broad range of important public health indicators through an interactive web-based application that provides access to...

  11. Gestalt Interactional Groups

    Science.gov (United States)

    Harman, Robert L.; Franklin, Richard W.

    1975-01-01

    Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups interactionally. Interactions described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)

  12. Interacting agents in finance

    NARCIS (Netherlands)

    Hommes, C.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response

  13. Summary of the TeV33 working group

    International Nuclear Information System (INIS)

    Bagley, P.P.; Bieniosek, F.M.; Colestock, P.

    1996-10-01

    This summary of the TeV33 working group at Snowmass reports on work in the areas of Tevatron store parameters, the beam-beam interaction, Main Injector intensity (slip stacking), antiproton production, and electron cooling

  14. Gaze Interactive Building Instructions

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Ahmed, Zaheer; Mardanbeigi, Diako

    We combine eye tracking technology and mobile tablets to support hands-free interaction with digital building instructions. As a proof-of-concept we have developed a small interactive 3D environment where one can interact with digital blocks by gaze, keystroke and head gestures. Blocks may be moved...

  15. Convergence in Multispecies Interactions

    OpenAIRE

    Bittleston, Leonora Sophia; Pierce, Naomi E.; Ellison, Aaron M.; Pringle, Anne

    2016-01-01

    The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent inter...

  16. Restricted Variance Interaction Effects

    DEFF Research Database (Denmark)

    Cortina, Jose M.; Köhler, Tine; Keeler, Kathleen R.

    2018-01-01

    Although interaction hypotheses are increasingly common in our field, many recent articles point out that authors often have difficulty justifying them. The purpose of this article is to describe a particular type of interaction: the restricted variance (RV) interaction. The essence of the RV int...

  17. 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

  18. Media Facades beyond Interaction

    DEFF Research Database (Denmark)

    Fritsch, Jonas

    2008-01-01

    As part of a the research project Digital Urban Living [www.digitalurbanliving.dk], we have taken part in the design of two large-scale installations that employ interactive technologies to facilitate participation and foster social interactions in public, urban settings. We present the two cases......, Aarhus by Light and Projected Poetry, and discuss the future trajectory of our work in this field, as well as some of our findings regarding the challenges of designing large-scale public interactive installations. In doing so, we specifically highlight the possibilities in relation to designing...... for affective experience and engaging interaction that advocate for a long-term interactive experience....

  19. Convergence in Multispecies Interactions.

    Science.gov (United States)

    Bittleston, Leonora S; Pierce, Naomi E; Ellison, Aaron M; Pringle, Anne

    2016-04-01

    The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent interactions in a comparative context is likely to facilitate prediction of the ecological roles of organisms (including microbes) in multispecies interactions and selective pressures acting in poorly understood or newly discovered multispecies systems. We illustrate the concept of convergent interactions with examples: vertebrates and their gut bacteria; ectomycorrhizae; insect-fungal-bacterial interactions; pitcher-plant food webs; and ants and ant-plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Expected damage to accelerator equipment due to the impact of the full LHC beam: beam instrumentation, experiments and simulations

    CERN Document Server

    Burkart, Florian

    The Large Hadron Collider (LHC) is the biggest and most powerful particle accelerator in the world, designed to collide two proton beams with particle momentum of 7 TeV/c each. The stored energy of 362MJ in each beam is sufficient to melt 500 kg of copper or to evaporate about 300 liter of water. An accidental release of even a small fraction of the beam energy can cause severe damage to accelerator equipment. Reliable machine protection systems are necessary to safely operate the accelerator complex. To design a machine protection system, it is essential to know the damage potential of the stored beam and the consequences in case of a failure. One (catastrophic) failure would be, if the entire beam is lost in the aperture due to a problem with the beam dumping system. This thesis presents the simulation studies, results of a benchmarking experiment, and detailed target investigation, for this failure case. In the experiment, solid copper cylinders were irradiated with the 440GeV proton beam delivered by the ...

  1. Space charge effects: tune shifts and resonances

    International Nuclear Information System (INIS)

    Weng, W.T.

    1986-08-01

    The effects of space charge and beam-beam interactions on single particle motion in the transverse degree of freedom are considered. The space charge force and the resulting incoherent tune shift are described, and examples are given from the AGS and CERN's PSB. Equations of motion are given for resonances in the presence of the space charge force, and particle behavior is examined under resonance and space charge conditions. Resonance phase space structure is described with and without space charge. Uniform and bunched beams are compared. Beam-beam forces and resonances and beam-beam detuning are described. 18 refs., 15 figs

  2. Food-drug interactions

    DEFF Research Database (Denmark)

    Schmidt, Lars E; Dalhoff, Kim

    2002-01-01

    Interactions between food and drugs may inadvertently reduce or increase the drug effect. The majority of clinically relevant food-drug interactions are caused by food-induced changes in the bioavailability of the drug. Since the bioavailability and clinical effect of most drugs are correlated......, the bioavailability is an important pharmacokinetic effect parameter. However, in order to evaluate the clinical relevance of a food-drug interaction, the impact of food intake on the clinical effect of the drug has to be quantified as well. As a result of quality review in healthcare systems, healthcare providers...... are increasingly required to develop methods for identifying and preventing adverse food-drug interactions. In this review of original literature, we have tried to provide both pharmacokinetic and clinical effect parameters of clinically relevant food-drug interactions. The most important interactions are those...

  3. Grasp interaction with tablets

    CERN Document Server

    Wolf, Katrin

    2015-01-01

    This book presents guidelines for a future device type: a tablet that allows ergonomic front- and back-of-device interaction. These guidelines help designers and developers of user interfaces to build ergonomic applications for tablet devices, in particular for devices that enable back-of-device interaction. In addition, manufacturers of tablet devices obtain arguments that back-of-device interaction is a promising extension of the interaction design space and results in increased input capabilities, enriched design possibilities, and proven usability. The guidelines are derived from empirical studies and developed to fit the users’ skills to the way the novel device type is held. Three particular research areas that are relevant to develop design guidelines for tablet interaction are investigated: ergonomic gestures, interaction areas, and pointing techniques.

  4. Quantum interaction. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bruza, Peter [Queensland Univ. of Technology, Brisbane (Australia). Faculty of Science and Technology; Sofge, Donald [Navy Center for Applied Research in Artificial Intelligence, Washington, DC (United States). Naval Research Lab.; Lawless, William [Paine Coll., Augusta, GA (United States); Rijsbergen, Keith van [Glasgow Univ. (United Kingdom). Dept. of Computing Science; Klusch, Matthias (eds.) [German Research Center for Artificial Intelligence, Saarbruecken (Germany)

    2009-07-01

    This book constitutes the refereed proceedings of the Third International Symposium on Quantum Interaction, QI 2009, held in Saarbruecken, Germany, in March 2009. The 21 revised full papers presented together with the 3 position papers were carefully reviewed and selected from numerous submissions. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, decision theory, information retrieval, information systems, social interaction, computational linguistics and finance. (orig.)

  5. Food-Drug Interactions

    Directory of Open Access Journals (Sweden)

    Arshad Yar Khan

    2011-03-01

    Full Text Available The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction, food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction or another disease the person has (drug-disease interaction. A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug interactions physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug interactions, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug interactions result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least fooddrug interactions. The literature survey was conducted by extracting data from different review and original articles on general or specific drug interactions with food. This review gives information about various interactions between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient.

  6. Quantum interaction. Proceedings

    International Nuclear Information System (INIS)

    Bruza, Peter; Rijsbergen, Keith van

    2009-01-01

    This book constitutes the refereed proceedings of the Third International Symposium on Quantum Interaction, QI 2009, held in Saarbruecken, Germany, in March 2009. The 21 revised full papers presented together with the 3 position papers were carefully reviewed and selected from numerous submissions. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, decision theory, information retrieval, information systems, social interaction, computational linguistics and finance. (orig.)

  7. Interactive Strategy-Making

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    This article outlines an interactive strategy-making model that combines central reasoning with ongoing learning from decentralised responses. The management literature often presents strategy as implementing an optimal plan identified through rational analysis and ascribes potential shortcomings...... to failed communication and execution of the planned actions. However, effective strategy-making comprises both central reasoning from forward-looking planning considerations and decentralised responses to emerging events as interacting elements in a dynamic adaptive system. The interaction between...

  8. Interactions in multispecies biofilms

    DEFF Research Database (Denmark)

    Burmølle, Mette; Ren, Dawei; Bjarnsholt, Thomas

    2014-01-01

    The recent focus on complex bacterial communities has led to the recognition of interactions across species boundaries. This is particularly pronounced in multispecies biofilms, where synergistic interactions impact the bacterial distribution and overall biomass produced. Importantly, in a number...... of settings, the interactions in a multispecies biofilm affect its overall function, physiology, or surroundings, by resulting in enhanced resistance, virulence, or degradation of pollutants, which is of significant importance to human health and activities. The underlying mechanisms causing these synergistic...

  9. Theory of particle interactions

    International Nuclear Information System (INIS)

    Belokurov, V.V.; Shirkov, D.V.

    1986-01-01

    Development and modern state of the theory of elementary particle interactions is described. The main aim of the paper is to give a picture of quantum field theory development in the form easily available for physicists not occupied in this field of science. Besides the outline of chronological development of main representations, the description of renormalization and renorm-groups, gauge theories, models of electro-weak interactions and quantum chromodynamics, the latest investigations related to joining all interactions and supersymmetries is given

  10. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  11. Proxemic Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Porcheron, Martin; Lucero, Andrés; Quigley, Aaron

    2016-01-01

    and their digital devices (i.e. the proxemic relationships). Building on the ideas of proxemic interactions, this workshop is motivated by the concept of ‘proxemic mobile collocated interactions’, to harness new or existing technologies to create engaging and interactionally relevant experiences. Such approaches......Recent research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices. However, existing practices fail to fully account for the culturally-dependent spatial relationships between people...... in exploring proxemics and mobile collocated interactions....

  12. Framing interactive methods

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2011-01-01

    Two paradigms of organization and leadership is outlined and compared. A theoretical model of interactive leadership is developed, combining learning, knowledge flow, leadership and organizational principles....

  13. Two interacting Hofstadter butterflies

    International Nuclear Information System (INIS)

    Barelli, A.; Bellissard, J.; Jacquod, P.

    1997-01-01

    The problem of two interacting particles in a quasiperiodic potential is addressed. Using analytical and numerical methods, we explore the spectral properties and eigenstates structure from the weak to the strong interaction case. More precisely, a semiclassical approach based on noncommutative geometry techniques is used to understand the intricate structure of such a spectrum. An interaction induced localization effect is furthermore emphasized. We discuss the application of our results on a two-dimensional model of two particles in a uniform magnetic field with on-site interaction. copyright 1997 The American Physical Society

  14. Philosophy of Interaction

    DEFF Research Database (Denmark)

    Svanæs, Dag

    2011-01-01

    This is an encyclopedia entry for the Interaction-Design.org free IxD encyclopedia. The topic of the entry is the application of the philosophy of Heidegger and Merleau-Ponty to a theory of interactivity. Comments by Don Norman and Eva Hornecker.......This is an encyclopedia entry for the Interaction-Design.org free IxD encyclopedia. The topic of the entry is the application of the philosophy of Heidegger and Merleau-Ponty to a theory of interactivity. Comments by Don Norman and Eva Hornecker....

  15. Kinetics of depletion interactions

    NARCIS (Netherlands)

    Vliegenthart, G.A.; Schoot, van der P.P.A.M.

    2003-01-01

    Depletion interactions between colloidal particles dispersed in a fluid medium are effective interactions induced by the presence of other types of colloid. They are not instantaneous but built up in time. We show by means of Brownian dynamics simulations that the static (mean-field) depletion force

  16. Curiosity and Interaction

    NARCIS (Netherlands)

    Tieben, R.; Bekker, M.M.; Schouten, B.A.M.

    2011-01-01

    We explore the concepts of curiosity and interaction: how can we elicit curiosity in public spaces through interactive systems? We have developed a model consisting of five curiosity-evoking principles. In an iterative design research approach, we have explored the design implementations of these

  17. Storyboarding Multimedia Interactions.

    Science.gov (United States)

    Martin, Linda C.

    2000-01-01

    Understanding how to include interactivity when designing multimedia-based training (MBT) storyboards is a major key for a successful MBT. Discusses the basic formats of interactions and when to use each format. Describes how to storyboard and areas to address, including: the display area, prompts, branching, programming and graphics notes,…

  18. Designing for Interaction Proxemics

    DEFF Research Database (Denmark)

    Grønbæk, Jens Emil

    2018-01-01

    Design of interactive technology provides opportunities as well as constraints in how a group of users can organize in a shared space. The core argument of interaction proxemics is to consider this in designing for collaboration. In my thesis, I focus on conceptualizing design of ubicomp...

  19. INTERACT Station Catalogue - 2015

    DEFF Research Database (Denmark)

    INTERACT stations are located in all major environmental envelopes of the Arctic providing an ideal platform for studying climate change and its impact on the environment and local communities. Since alpine environments face similar changes and challenges as the Arctic, the INTERACT network also ...... catalogue includes descriptions of 73 research stations included in the network at the time of printing....

  20. Electroweak interactions in nuclei

    International Nuclear Information System (INIS)

    Henley, E.M.

    1984-06-01

    Topics include: introduction to electroweak theory; the Weinberg-Salam theory for leptons; the Weinberg-Salam theory for hadrons-the GIM mechanism; electron scattering as a probe of the electroweak interaction (observation of PV, the weak interaction for nucleons, and parity violation in atoms); and time reversed invariance and electric dipole moments of nucleons, nuclei, and atoms. 52 references

  1. Elementary particle interactions

    International Nuclear Information System (INIS)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.

    1990-10-01

    This report discusses freon bubble chamber experiments exposed to μ + and neutrinos, photon-proton interactions; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle interactions; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics

  2. Foreign language interactive didactics

    Directory of Open Access Journals (Sweden)

    Arnaldo Moisés Gómez

    2016-06-01

    Full Text Available Foreign Language Interactive Didactics is intended for foreign language teachers and would-be teachers since it is an interpretation of the foreign language teaching-learning process is conceived from a reflexive social interaction. This interpretation declares learning based on interactive tasks that provide learners with opportunities to interact meaningfully among them, as a way to develop interactional competence as objective in itself and as a means to obtain communicative competence. Foreign language interactive didactics claims for the unity of reflection and action while learning the language system and using it to communicate, by means of solving problems presented in interactive tasks. It proposes a kind of teaching that is interactive, developmental, collaborative, holist, cognitive, problematizing, reflexive, student centered, humanist, and with a strong affective component that empower the influencing psychological factors in learning. This conception appears in the book: DIDÁCTICA INTERACTIVA DE LENGUAS (2007 y 2010. The book is used as a textbook for the subject of Didactics that is part of the curriculum in language teachers’ formation of all the pedagogical sciences universities, in Spanish teachers’ formation who are not Spanish speaking people at Havana University, and also as a reference book for postgraduate courses, master’s and doctorate’ s degrees.

  3. Interactive baby feeding bottle

    NARCIS (Netherlands)

    2013-01-01

    An interactive baby bottle with an electronic unit is disclosed. The electronic unit comprises a sensor unit configured to sense the heart beat of a person bottle feeding a baby and an actuator unit configured to transmit the sensed heart beat to the baby. The disclosed interactive baby bottle can

  4. Drug interactions with radiopharmaceuticals

    International Nuclear Information System (INIS)

    Hesslewood, S.; Leung, E.

    1994-01-01

    Considerable information on documented drug and radiopharmaceutical interactions has been assembled in a tabular form, classified by the type of nuclear medicine study. The aim is to provide a rapid reference for nuclear medicine staff to look for such interactions. The initiation of drug chart monitoring or drug history taking of nuclear medicine patients and the reporting of such events are encouraged. (orig.)

  5. Let Social Interaction Flourish

    Science.gov (United States)

    Case, Anny Fritzen

    2016-01-01

    The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive interaction among English learners and peers who are native speakers. The potential benefits of students who are just learning English interacting socially…

  6. Photon-photon interactions

    International Nuclear Information System (INIS)

    Gilman, F.J.

    1980-01-01

    A brief summary of the present status of photon-photon interactions is presented. Stress is placed on the use of two-photon collisions to test present ideas on the quark constituents of hadrons and on the theory of strong interactions

  7. Computations and interaction

    NARCIS (Netherlands)

    Baeten, J.C.M.; Luttik, S.P.; Tilburg, van P.J.A.; Natarajan, R.; Ojo, A.

    2011-01-01

    We enhance the notion of a computation of the classical theory of computing with the notion of interaction. In this way, we enhance a Turing machine as a model of computation to a Reactive Turing Machine that is an abstract model of a computer as it is used nowadays, always interacting with the user

  8. Antiproton-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    Several facets of antinucleon-nucleus interactions are explored. The topics treated are: coherent interactions, production of unusual states and particles in the nuclear medium, and the creation of extreme states of matter by antimatter annihilation. It is found that temperatures of the magnitude necessary to achieve the predicted quark-gluon phase transition are obtained. 20 references

  9. Media Facades beyond Interaction

    DEFF Research Database (Denmark)

    Fritsch, Jonas

    2008-01-01

    As part of a the research project Digital Urban Living [www.digitalurbanliving.dk], we have taken part in the design of two large-scale installations that employ interactive technologies to facilitate participation and foster social interactions in public, urban settings. We present the two cases...

  10. Interaction Analysis and Supervision.

    Science.gov (United States)

    Amidon, Edmund

    This paper describes a model that uses interaction analysis as a tool to provide feedback to a teacher in a microteaching situation. The author explains how interaction analysis can be used for teacher improvement, describes the category system used in the model, the data collection methods used, and the feedback techniques found in the model. (JF)

  11. Interaction of atmospheric pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Bustueva, K A; Sanotsky, I V

    1975-01-01

    In evaluating the health effects of chemical and physical factors, it is of great importance to know the possible interactions between different pollutants. The biological effects of interactions, when present, may be synergistic, antagonistic or additive. Each type of interaction calls for a different evaluation and different practical measures. As yet the understanding of such effects is not clear, probably because of differing definitions of terminology. For example, the combined effect of sulfur dioxide and particulates is interpreted as a synergistic effect; in the author's opinion, this is an aggravating effect. The type of interaction depends on the levels of concentration observed, for example, the synergism shown at high levels of concentration is not always demonstrated for low levels of concentration. In fact there is little evidence of synergistic effects from ambient air pollutant; the more common type of interaction is additive in effect. 12 references.

  12. Diachronic Perspective and Interaction

    DEFF Research Database (Denmark)

    Marchetti, Emanuela; Valente, Andrea

    . An ongoing participatory inquiry is being conducted, to explore deeper forms of learning and communication for historical museums. Our hypothesis is that the diachronic perspective on historical processes, defined as social interaction within the environment through time, is a key missing element....... Although this interaction style may appeal to teachers, as it reminds of school teaching, it has several disadvantages: a dialogue never occurs between adults and children, who listen in silence, hence it becomes hard to evaluate what has being learnt and how deeply, and finally it is not very engaging....... Explorations of more interactive representations of the diachronic perspective, through play and tangible interaction, may foster a dialogue with young visitors. Therefore, a new interactive installation is being designed, intended as a tool to enrich learning, allowing children to experience historical...

  13. Density dependent effective interactions

    International Nuclear Information System (INIS)

    Dortmans, P.J.; Amos, K.

    1994-01-01

    An effective nucleon-nucleon interaction is defined by an optimal fit to select on-and half-off-of-the-energy shell t-and g-matrices determined by solutions of the Lippmann-Schwinger and Brueckner-Bethe-Goldstone equations with the Paris nucleon-nucleon interaction as input. As such, it is seen to better reproduce the interaction on which it is based than other commonly used density dependent effective interactions. The new (medium modified) effective interaction when folded with appropriate density matrices, has been used to define proton- 12 C and proton- 16 O optical potentials. With them elastic scattering data are well fit and the medium effects identifiable. 23 refs., 8 figs

  14. Magnetic interactions between nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Mikkel Fougt; Frandsen, Cathrine

    2010-01-01

    We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state...... of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples...... of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions....

  15. Nonlinear dynamics aspects of particle accelerators

    International Nuclear Information System (INIS)

    Jowett, J.M.; Turner, S.; Month, M.

    1986-01-01

    These proceedings contain the lectures presented at the named winter school. They deal with the application of dynamical systems to accelerator theory. Especially considered are the statistical description of charged-beam plasmas, integrable and nonintegrable Hamiltonian systems, single particle dynamics and nonlinear resonances in circular accelerators, nonlinear dynamics aspects of modern storage rings, nonlinear beam-beam resonances, synchro-betatron resonances, observations of the beam-beam interactions, the dynamics of the beam-beam interactions, beam-beam simulations, the perturbation method in nonlinear dynamics, theories of statistical equilibrium in electron-positron storage rings, nonlinear dissipative phenomena in electron storage rings, the dynamical aperture, the transition to chaos for area-preserving maps, special processors for particle tracking, algorithms for tracking of charged particles in circular accelerators, the breakdown of stability, and a personal perspective of nonlinear dynamics. (HSI)

  16. Nonlinear dynamics aspects of particle accelerators. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Jowett, J M; Turner, S; Month, M

    1986-01-01

    These proceedings contain the lectures presented at the named winter school. They deal with the application of dynamical systems to accelerator theory. Especially considered are the statistical description of charged-beam plasmas, integrable and nonintegrable Hamiltonian systems, single particle dynamics and nonlinear resonances in circular accelerators, nonlinear dynamics aspects of modern storage rings, nonlinear beam-beam resonances, synchro-betatron resonances, observations of the beam-beam interactions, the dynamics of the beam-beam interactions, beam-beam simulations, the perturbation method in nonlinear dynamics, theories of statistical equilibrium in electron-positron storage rings, nonlinear dissipative phenomena in electron storage rings, the dynamical aperture, the transition to chaos for area-preserving maps, special processors for particle tracking, algorithms for tracking of charged particles in circular accelerators, the breakdown of stability, and a personal perspective of nonlinear dynamics. (HSI).

  17. Drug-radiopharmaceutical interactions

    International Nuclear Information System (INIS)

    Hladik, W.B.; Ponto, J.A.; Stathis, V.J.

    1985-01-01

    Patients seen in the nuclear medicine department have a wide variety of disorders and, consequently, may be receiving any number of therapeutic drugs. For this reason, nuclear medicine professionals should be aware of the potential effects that these pharmacologic agents may have on the bio-distribution of subsequently administered radiopharmaceuticals, commonly referred to as ''drug-radiopharmaceutical interactions.'' Compared with the quantity of literature written about interactions between various therapeutic drugs, the information available on drug-radiopharmaceutical interactions is scarce. However, there has been increasing interest in this subject, particularly during the past five years. Some of the reported interactions are used intentionally to add a new dimension to the nuclear medicine study and increase its diagnostic capabilities, i.e., pharmacologic intervention. These beneficial ''interactions'' are discussed in detail in several other chapters of this book. Other interactions, however, cause changes in the normal distribution of radiopharmaceuticals, which may interfere with the diagnostic utility of various nuclear medicine procedures. The latter group of interactions is the focus of this chapter

  18. An Experimental Approach to Simulations of the CLIC Interaction Point

    DEFF Research Database (Denmark)

    Esberg, Jakob

    2012-01-01

    with respect to the luminosity weighted depolarization is discussed. In the chapter on muons, the implementation of the production of incoherent muons in GUINEA-PIG++ will be discussed. Comments on the correctness and completeness of the implementation of muon production will be presented. The chapter...... experiments conducted at MAMI will be presented. Furthermore the chapter discusses the performance of new CMOS based detectors to be used in future experiments by the NA63 collaboration. The chapter on collider simulations introduces the beam-beam simulation codes GUINEA-PIG and GUINEA-PIG++, their methods...... of operation and their features. The characteristics of the simulated particles are presented and a comparison between the outputs of these codes with those from CAIN. \\item In the chapter on tridents, the implementation of the direct trident process in GUINEA-PIG++ is described. The results are compared...

  19. Sketches in Embodied Interaction

    DEFF Research Database (Denmark)

    Erkut, Cumhur; Dahl, Sofia; Triantafyllidis, Georgios

    2014-01-01

    and provide a simple example as a design outcome. The variety and the qualities of the initial ideas indicate that this approach might provide a better foundation for our participants, compared to the approaches that focus only on technologies. The interactive sketches were demonstrated at the conference.......We present an approach for teaching and designing embodied interaction based on interactive sketches. We have combined the mover perspective and felt experiences of movement with advanced technologies (multi-agents, physical simulations) in a generative design session. We report our activities...

  20. Interaction university and school

    Directory of Open Access Journals (Sweden)

    Gionara Tauchen

    2016-05-01

    Full Text Available Considering that the interaction between universities and middle schools is fundamental for organization and the qualification of the education system, we conducted a qualitative study on twenty public municipal schools of Rio Grande, RS, designed to investigate and understand the effectiveness of university activities (teaching, research and extension in regard to the promotion and strengthening of the interactions between these institutions. We highlight the activities related to Pibid, the Education Observatory, extension, supervised internships, and to undergraduate and postgraduate research. From comprehensions about these activities, we discuss the interaction between school and university.

  1. Multiactivity in Social Interaction

    DEFF Research Database (Denmark)

    Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitasking...... by using video recordings of real-life interactions from a range of different contexts, such as medical settings, office workplaces and car driving. With the companion collection Interacting with Objects: Language, materiality, and social activity, the book advances understanding of the complex...

  2. Plasma-wall interactions

    International Nuclear Information System (INIS)

    Behrisch, Rainer

    1978-01-01

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  3. Mainz/PSI φ-factory design considerations

    International Nuclear Information System (INIS)

    Streun, A.

    1991-01-01

    Design considerations for a φ-factory with a Luminosity of the order of 10 33 cm -2 s -1 lead to the concept of a multi-bunch round beam double storage ring with superconducting solenoids for micro-beta focusing and beam rotation. Simulations of the beam-beam-interaction indicate, that significantly higher beam-beam-parameters may become possible with round beams. A rough draft design of a round beam φ-factory is presented. (orig.)

  4. Performance limitations at ISABELLE

    International Nuclear Information System (INIS)

    Keil, E.

    1975-01-01

    The transverse stability of coasting beams in the planned ISABELLE storage rings was studied. The beam--beam tune shift limitation at 0.005 can be avoided, and a computer simulation seems to show 0.005 is a pessimistic limit. For beams of reasonable smoothness on the edge, the actual limit should be somewhat higher. Some coupling effects due to the beam--beam interaction are also examined

  5. Intermediate energy electromagnetic interactions

    International Nuclear Information System (INIS)

    Garcon, M.

    1994-11-01

    Polarization measurements in electromagnetic interactions are reviewed. Deep inelastic scattering of polarized electrons and muons an polarized targets, photoproduction of pseudoscalar mesons on protons, photonuclear reactions, and the electromagnetic structure of the deuteron are discussed. (K.A.)

  6. Intermediate energy electromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Garcon, M.

    1994-11-01

    Polarization measurements in electromagnetic interactions are reviewed. Deep inelastic scattering of polarized electrons and muons an polarized targets, photoproduction of pseudoscalar mesons on protons, photonuclear reactions, and the electromagnetic structure of the deuteron are discussed. (K.A.).

  7. Interaction as Negotiation

    DEFF Research Database (Denmark)

    Kristensen, Jannie Friis; Nielsen, Christina

    In this paper we discuss recent developments in interaction design principles for ubiquitous computing environments, specifically implications related to situated and mobile aspects of work. We present 'Interaction through Negotiation' as a general Human-Computer Interaction (HCI) paradigm, aimed...... at ubiquitous/pervasive technology and environments, with focus on facilitating negotiation in and between webs of different artifacts, humans and places. This approach is concerned with the way technology presents itself to us, both as physical entities and as conceptual entities, as well as the relations...... on several extensive empirical case studies, as well as co-operative design-sessions, we present a reflective analysis providing insights into results of the "Interaction through Negotiation" design approach in action. A very promising area of application is exception handling in pervasive computing...

  8. Atomic and Molecular Interactions

    International Nuclear Information System (INIS)

    2002-01-01

    The Gordon Research Conference (GRC) on Atomic and Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field

  9. Elementary particle interactions

    International Nuclear Information System (INIS)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.

    1992-10-01

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out

  10. ENTREPRENEURSHIP AS SOCIAL INTERACTION

    DEFF Research Database (Denmark)

    Larsen, Henry; Lima, Patricia; Olsen, Bente

    2013-01-01

    This paper aims to explore how entrepreneurs work with innovation; to explore and develop attention points in understanding entrepreneurship as social processes of interaction between people. Through interviews and engagement with entrepreneurs and key stakeholders, their actual social practices...... entrepreneurship as socially constructed through local interactions between players and identify key themes in these interactions within the organisation, such as leadership, becoming part of the initiative and trust/mistrust. By doing so, this paper contributes to an understanding of entrepreneurship as social...... and the influence on the progress as innovators are explored. It is focused on a new local activity in a Danish town, named the I-factory which has within a year gathered almost 40 entrepreneurs. As a part of the interaction, there were created activities to encourage even more collaboration. We see...

  11. Multiactivity in Social Interaction

    DEFF Research Database (Denmark)

    Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitasking...... offers a fresh view to the phenomenon by presenting studies that explore how two or more activities can be related and made co-relevant as people interact with one another. The studies build on the basis that multiactivity is a social, verbal and embodied phenomenon. They investigate multiactivity...... by using video recordings of real-life interactions from a range of different contexts, such as medical settings, office workplaces and car driving. With the companion collection Interacting with Objects: Language, materiality, and social activity, the book advances understanding of the complex...

  12. Chasing Ecological Interactions.

    Science.gov (United States)

    Jordano, Pedro

    2016-09-01

    Basic research on biodiversity has concentrated on individual species-naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species interact with other species to provide functional support for the Tree of Life. Ecological interactions may be lost well before the species involved in those interactions go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species interactions and how basic research is helping us address the fast-paced extinction of species due to human activities.

  13. Air-Sea Interaction

    Science.gov (United States)

    Csanady, G. T.

    2001-03-01

    In recent years air-sea interaction has emerged as a subject in its own right, encompassing small-scale and large-scale processes in both air and sea. Air-Sea Interaction: Laws and Mechanisms is a comprehensive account of how the atmosphere and the ocean interact to control the global climate, what physical laws govern this interaction, and its prominent mechanisms. The topics covered range from evaporation in the oceans, to hurricanes, and on to poleward heat transport by the oceans. By developing the subject from basic physical (thermodynamic) principles, the book is accessible to graduate students and research scientists in meteorology, oceanography, and environmental engineering. It will also be of interest to the broader physics community involved in the treatment of transfer laws, and thermodynamics of the atmosphere and ocean.

  14. Interactive Topology Optimization

    DEFF Research Database (Denmark)

    Nobel-Jørgensen, Morten

    Interactivity is the continuous interaction between the user and the application to solve a task. Topology optimization is the optimization of structures in order to improve stiffness or other objectives. The goal of the thesis is to explore how topology optimization can be used in applications...... on theory of from human-computer interaction which is described in Chapter 2. Followed by a description of the foundations of topology optimization in Chapter 3. Our applications for topology optimization in 2D and 3D are described in Chapter 4 and a game which trains the human intuition of topology...... optimization is presented in Chapter 5. Topology optimization can also be used as an interactive modeling tool with local control which is presented in Chapter 6. Finally, Chapter 7 contains a summary of the findings and concludes the dissertation. Most of the presented applications of the thesis are available...

  15. Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Lucero, Andrés; Clawson, James; Lyons, Kent

    2015-01-01

    Mobile devices such as smartphones and tablets were originally conceived and have traditionally been utilized for individual use. Research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices, thus...... going from personal/individual toward shared/multiuser experiences and interactions. However, computers are getting smaller, more powerful, and closer to our bodies. Therefore, mobile collocated interactions research, which originally looked at smartphones and tablets, will inevitably include ever......-smaller computers, ones that can be worn on our wrists or other parts of the body. The focus of this workshop is to bring together a community of researchers, designers and practitioners to explore the potential of extending mobile collocated interactions to the use of wearable devices....

  16. Magnon Interactions in Terbium

    DEFF Research Database (Denmark)

    Nielsen, Mourits; Bjerrum Møller, Hans; Mackintosh, Allan

    1970-01-01

    Magnon energies and lifetimes have been studied in Tb and Tb-10% Ho single crystals by inelastic neutron scattering. The lifetimes of magnons propagating in the c-direction have been measured in the ferromagnetic phase of Tb, and are found to decrease with increasing temperature and wave......-vector, probably principally due to magnon-magnon interactions. The interaction of magnons with phonons has also been observed and the effect of Ho impurities on this interaction studied. In addition, excitations which are ascribed to local modes associated with the Ho ions have been observed. The dependence...... of the indirect exchange interaction on temperature in the alloy gives information on the mechanisms responsible for the transition from the helical to ferromagnetic structures. The dependence of the magnon energies on magnetic field at low temperatures gives detailed information on the role of magnetoelastic...

  17. Fibronectin-cell interactions

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, M R; Woods, A

    1990-01-01

    Fibronectins are widespread extracellular matrix and body fluid glycoproteins, capable of multiple interactions with cell surfaces and other matrix components. Their structure at a molecular level has been resolved, yet there are still many unanswered questions regarding their biologic activity...... in vivo. Much data suggests that fibronectins may promote extracellular matrix assembly, and cell adhesion to those matrices. However, one outstanding enigma is that fibronectins may, under different circumstances, promote both cell migration and anchorage. An analysis of the interaction of fibroblasts...... with proteolytically derived and purified domains of plasma fibronectin revealed that the type of adhesion and the correlated cytoskeletal organization depended on multiple interactions of fibronectin domains with the cell surface. Human dermal fibroblasts were capable of interacting with the integrin-binding domain...

  18. Host–Pathogen Interactions

    NARCIS (Netherlands)

    Smits, M.A.; Schokker, D.J.

    2011-01-01

    The outcome of an infection is determined by numerous interactions between hosts and pathogens occurring at many different biological levels, ranging from molecule to population. To develop new control strategies for infectious diseases in livestock species, appropriate methodologies are needed

  19. Quark-quark interactions

    International Nuclear Information System (INIS)

    Jacob, M.

    1982-01-01

    This chapter discusses interactions only at the constituent level, as observed in hadron-hadron collisions. It defines quarks and gluons as constituents of the colliding hadrons, reviews some applications of perturbative OCD, discussing in turn lepton pair production, which in lowest order approximation corresponds to the Drell-Yan process. It investigates whether quark-quark interactions could not lead to some new color structure different from those prevalent for known baryons and mesons, which could be created in hadron interactions, and whether color objects (not specifically quarks or gluons) could not appear as free particles. Discussed is perturbative QCD in hadron collisions; the quark approach to soft processes; and new color structures. It points out that perturbative QCD has been at the origin of much progress in the understanding of hadron interactions at the constituent level

  20. Semi-leptonic interactions

    International Nuclear Information System (INIS)

    Gaillard, J.M.

    In spite of the presence of poorly understood strong interaction effects, the theory of hadronic currents leads to a considerable predictive power. This is shown in the discussion of the semi-leptonic decays

  1. Fundamentals of Filament Interaction

    Science.gov (United States)

    2017-05-19

    AFRL-AFOSR-VA-TR-2017-0110 FUNDAMENTALS OF FILAMENT INTERACTION Martin Richardson UNIVERSITY OF CENTRAL FLORIDA Final Report 06/02/2017 DISTRIBUTION...of Filament Interaction 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA95501110001 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Martin Richardson 5d. PROJECT...NAME OF RESPONSIBLE PERSON Martin Richardson a. REPORT b. ABSTRACT c. THIS PAGE 19b. TELEPHONE NUMBER (Include area code) 407-823-6819 Standard Form

  2. Succeeding with interactive research

    DEFF Research Database (Denmark)

    Krogh, Andreas Hagedorn; Nielsen, Morten Velsing

    2017-01-01

    the capacity for critique and ensuring that scientific standards are met. Based on our own experience and theories of interactive governance, network management and collaborative leadership, as well as on existing methodological literature, we provide guidance and suggest concrete tools and methods......Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research...

  3. Interaction quality: a review

    OpenAIRE

    Ultes, Stefan; Minker, Wolfgang

    2013-01-01

    Automatically deriving the quality of a Spoken Dialogue System is an important task for both assessing dialogue systems and improving them. Work on automatic quality estimation for each system-user-exchange further holds the opportunity of using this quality information for online-adaption of the dialogues. The Interaction Quality paradigm is the first metric holding those features. Hence, this contribution gives an overview over the Interaction Quality paradigm and reviews recent estimation ...

  4. Quantum interaction. Selected papers

    Energy Technology Data Exchange (ETDEWEB)

    Atmanspacher, Harald [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Haven, Emmanuel [Leicester Univ. (United Kingdom). School of Management; Kitto, Kirsty [Queensland Univ. of Technology, Brisbane, QLD (Australia); Raine, Derek (ed.) [Leicester Univ. (United Kingdom). Centre for Interdisciplinary Science

    2014-07-01

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  5. Smoking and Social Interaction

    OpenAIRE

    Panu Poutvaara; Lars-H.R. Siemers

    2007-01-01

    We study the social interaction of non-smokers and smokers as a sequential game, incorporating insights from social psychology and experimental economics into an economic model. Social norms a®ect human behavior such that non-smokers do not ask smokers to stop smoking and stay with them, even though disutility from smoking exceeds utility from social interaction. Overall, smoking is unduly often accepted when accommodating smoking is the social norm. The introduction of smoking and non-smokin...

  6. Interaction and observation, categorically

    Directory of Open Access Journals (Sweden)

    Vincenzo Ciancia

    2011-07-01

    Full Text Available This paper proposes to use dialgebras to specify the semantics of interactive systems in a natural way. Dialgebras are a conservative extension of coalgebras. In this categorical model, from the point of view that we provide, the notions of observation and interaction are separate features. This is useful, for example, in the specification of process equivalences, which are obtained as kernels of the homomorphisms of dialgebras. As an example we present the asynchronous semantics of the CCS.

  7. Soil-dithiocarbamate interactions

    International Nuclear Information System (INIS)

    Raghu, K.

    1980-01-01

    Soil is the ultimate repository of the pesticides applied for the control of plant pests and diseases. A variety of interactions like leaching, adsorption, chemical and microbial degradation etc take place between soil and pesticide. Results on work on two dialkyldithiocarbamates viz. thiram (tetramethylthiuram disulfide) and ziram (zinc dimethyldithiocarbamate) with respect to above interactions in soil are discussed and summarised. 35 S-labelled thiram and ziram were used in the studies. (author)

  8. Grapefruit and drug interactions.

    Science.gov (United States)

    2012-12-01

    Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug interactions with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed interactions. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug interactions with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in interactions with clinical consequences. Drugs interacting with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug interactions with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in interactions between drugs and grapefruit juice. In practice, numerous drugs interact with grapefruit juice. Although only a few

  9. Beam-Material Interaction

    CERN Document Server

    Mokhov, N.V.

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  10. Succeeding with interactive research

    DEFF Research Database (Denmark)

    Krogh, Andreas Hagedorn; Nielsen, Morten Velsing

    2017-01-01

    Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research...... the capacity for critique and ensuring that scientific standards are met. Based on our own experience and theories of interactive governance, network management and collaborative leadership, as well as on existing methodological literature, we provide guidance and suggest concrete tools and methods...

  11. Plasma-wall interaction

    International Nuclear Information System (INIS)

    Reichle, R.

    2004-01-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER

  12. Human-machine interactions

    Science.gov (United States)

    Forsythe, J Chris [Sandia Park, NM; Xavier, Patrick G [Albuquerque, NM; Abbott, Robert G [Albuquerque, NM; Brannon, Nathan G [Albuquerque, NM; Bernard, Michael L [Tijeras, NM; Speed, Ann E [Albuquerque, NM

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  13. K+-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    The K + -nucleus system is reviewed and comparison with data is made. The principal conclusions are that the theoretical uncertainties in relating the K + -nucleus interaction to the K + -nucleon interaction are very small and hence the positive kaon makes an excellent probe of the nucleus. It is suggested that this particle may be more sensitive to non-nucleonic degrees of freedom (especially quarks) than classical probes

  14. Interactive Virtual Cinematography

    OpenAIRE

    Burelli, Paolo

    2012-01-01

    A virtual camera represents the point-of-view of the player through which sheperceives the game world and gets feedback on her actions. Thus, the virtualcamera plays a vital role in 3D computer games and aects player experienceand enjoyability in games. Interactive virtual cinematography is the process ofvisualising the content of a virtual environment by positioning and animatingthe virtual camera in the context of interactive applications such as a computergame.Camera placement and animatio...

  15. Beam-Material Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N. V. [Fermilab; Cerutti, F. [CERN

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam interactions with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.

  16. Interacting Agegraphic Dark Energy

    OpenAIRE

    Wei, Hao; Cai, Rong-Gen

    2007-01-01

    A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\\'{a}rolyh\\'{a}zy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegrap...

  17. Quantum interaction. Selected papers

    International Nuclear Information System (INIS)

    Atmanspacher, Harald; Haven, Emmanuel; Raine, Derek

    2014-01-01

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  18. Interacting boson model with surface delta interaction between nucleons

    International Nuclear Information System (INIS)

    Druce, C.; Moszkowski, S.A.

    1984-01-01

    The surface delta interaction is used as an effective nucleon-nucleon interaction to investigate the structure and interaction of the bosons in the interacting boson model. The authors have obtained analytical expressions for the coefficients of a multipole expansion of the neutron-boson proton-boson interaction for the case of degenerate orbits

  19. Conducting interactive experiments online.

    Science.gov (United States)

    Arechar, Antonio A; Gächter, Simon; Molleman, Lucas

    2018-01-01

    Online labor markets provide new opportunities for behavioral research, but conducting economic experiments online raises important methodological challenges. This particularly holds for interactive designs. In this paper, we provide a methodological discussion of the similarities and differences between interactive experiments conducted in the laboratory and online. To this end, we conduct a repeated public goods experiment with and without punishment using samples from the laboratory and the online platform Amazon Mechanical Turk. We chose to replicate this experiment because it is long and logistically complex. It therefore provides a good case study for discussing the methodological and practical challenges of online interactive experimentation. We find that basic behavioral patterns of cooperation and punishment in the laboratory are replicable online. The most important challenge of online interactive experiments is participant dropout. We discuss measures for reducing dropout and show that, for our case study, dropouts are exogenous to the experiment. We conclude that data quality for interactive experiments via the Internet is adequate and reliable, making online interactive experimentation a potentially valuable complement to laboratory studies.

  20. Interactions between photodegradation components

    Directory of Open Access Journals (Sweden)

    Abdollahi Yadollah

    2012-09-01

    Full Text Available Abstract Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09, very low P-value (2 = 0.999, adjusted R-squared (Radj2 = 0.998, predicted R-squared (Rpred2 = 0.994 and the adequate precision (95.94. Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method.

  1. Electromagnetic processes and interactions

    International Nuclear Information System (INIS)

    Scheck, F.

    1983-01-01

    The electron and muon are important tools in testing the structure of the fundamental electromagnetic interactions. On the other hand, if these interactions are known, they serve as ideal probes for the internal structure of complex hadronic targets such as nucleons and nuclei. Purely electromagnetic interactions play a distinctive role, for obvious experimental reasons: At low and intermediate energies the effective electromagnetic coupling is larger by many orders of magnitude than the weak couplings, so that electromagnetic processes are measurable to much higher accuracy than purely weak processes. The present chapter deals primarily with applications of charged leptons to problems of nucleon and nuclear structure, and to selected precision tests of quantum electrodynamics (QED) at low momentum transfers. In most of these applications the electromagnetic interactions effectively appear in the form of external fields in the leptonic particle's Dirac equation. This is the domain where the physics of (electromagnetically) interacting leptons can still be described in the framework of an effective, though relativistic, single particle theory. (orig.)

  2. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  3. Secondary interactions in HIJET

    International Nuclear Information System (INIS)

    Longacre, R.S.

    1990-01-01

    This talk deals with the investigation of secondary interactions in proton-nucleus and nucleus-nucleus collisions using the Monte Carlo event generator HIJET. The HIJET generator considers p-A and A-A collisions to be a sum of independent N-N collisions, with the N-N cross section and scattering dynamics not dependent on whether the nucleon has previously participated in an interaction. It is very reasonable to assume that each collision should be well represented by an independent N-N collision, however the cross section for the forward going struck nucleon may be different. For each primary N-N interaction, a call is made to the MINBIAS routine of the program ISAJET - an event generator for high energy N-N interactions. MINBIAS computes the energy loss of the colliding nucleons and production of particles. MINBIAS is based on inclusive high energy N-N interactions forming multi-pomeron chains, with each chain fragmenting according to the Field-Feynman algorithm

  4. 5. Laser plasma interaction

    International Nuclear Information System (INIS)

    Labaune, C.; Fuchs, J.; Bandulet, H.

    2002-01-01

    Imprint elimination, smoothing and preheat control are considerable problems in inertial fusion and their possible solution can be achieved by using low-density porous materials as a buffer in target design. The articles gathered in this document present various aspects of the laser-plasma interaction, among which we have noticed: -) numerical algorithmic improvements of the Vlasov solver toward the simulation of the laser-plasma interaction are proposed, -) the dependence of radiation temperatures and X-ray conversion efficiencies of hohlraum on the target structures and laser irradiation conditions are investigated, -) a study of laser interaction with ultra low-density (0,5 - 20 mg/cm 3 ) porous media analyzing backscattered light at incident laser frequency ω 0 and its harmonics 3*ω 0 /2 and 2*ω 0 is presented, -) investigations of laser interaction with solid targets and crater formation are carried out with the objective to determine the ablation loading efficiency, -) a self organization in an intense laser-driven plasma and the measure of the relative degree of order of the states in an open system based on the S-theorem are investigated, and -) the existence and stability of electromagnetic solitons generated in a relativistic interaction of an intense laser light with uniform under-dense cold plasma are studied

  5. Tidal interaction of galaxies

    International Nuclear Information System (INIS)

    Kozlov, N.N.; Syunyaev, R.A.; Ehneev, T.M.

    1974-01-01

    One of the hypotheses explaining the occurrence of anomalous details in interacting galaxies has been investigated. Pairs of galaxies with 'tails' oppositely directed or neighbouring galaxies with cofferdams 'bridges', as if connecting the galaxies, are called interacting galaxies. The hypothesis connects the origin of cofferdams and 'tails' of interacting galaxies with tidal effects ; the action of power gravitational forces in the intergalactic space. A source of such forces may be neighbouring stellar systems or invisible bodies, for instance, 'dead' quasars after a gravitational collapse. The effect of large masses of matter on the galaxy evolution has been investigated in the Institute of Applied Mathematics of the Academy of Sciences of the USSSR in 1971-1972 by numerical simulation of the process on a digital computer with the subsequent data transmission on a display. Different versions of a massive body flight relative to a galaxy disk are considered. Photographs of a display screen at different moments of time are presented. As a result of mathematical simulation of galaxies gravitational interactions effects are discovered which resemble real structures in photographs of galaxies. It seems to be premature to state that namely these mechanisms cause the formation of 'tails' and cofferdams between galaxies. However, even now it is clear that the gravitational interaction strongly affects the dynamics of the stellar system evolution. Further studies should ascertain a true scale of this effect and its genuine role in galaxy evolution

  6. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Making an Interactive Calculus Textbook.

    Science.gov (United States)

    Larson, Timothy R.

    1995-01-01

    Presents a case study of the design and production of "Interactive Calculus," an interactive multimedia textbook. Discusses reasons for using multimedia textbooks; what an interactive textbook is; content, organization, graphic design, authoring and composition; and work flow. (AEF)

  8. New interactions for superstrings

    International Nuclear Information System (INIS)

    Greensite, J.; Klinkhamer, F.R.

    1987-01-01

    The supersymmetry relation {Q -A , Qsup(anti B}=2Hδsup(Aanti B) implies the existence of a new quartic vertex in the open superstring light-cone hamiltonian, if the supercharges are cubic in the string fields. Green and Schwarz have argued that this vertex almost vanishes, due to exact cancellations among fermionic operators, with perhaps a non-local interaction remaining. In this article we show that these exact cancellations do not occur for certain contributions to the anticommutator, and that new local, and possibly divergent, 4-string interactions are generated. On the basis of vacuum stability, we argue that 4-string interaction terms should also exist for closed superstring hamiltonians. (orig.)

  9. Dike/Drift Interactions

    Energy Technology Data Exchange (ETDEWEB)

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  10. Sonic Interaction Design

    DEFF Research Database (Denmark)

    ) challenges these prevalent approaches by considering sound as an active medium that can enable novel sensory and social experiences through interactive technologies. This book offers an overview of the emerging SID research, discussing theories, methods, and practices, with a focus on the multisensory......Sound is an integral part of every user experience but a neglected medium in design disciplines. Design of an artifact’s sonic qualities is often limited to the shaping of functional, representational, and signaling roles of sound. The interdisciplinary field of sonic interaction design (SID...... aspects of sonic experience. Sonic Interaction Design gathers contributions from scholars, artists, and designers working at the intersections of fields ranging from electronic music to cognitive science. They offer both theoretical considerations of key themes and case studies of products and systems...

  11. 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.

  12. Dike/Drift Interactions

    International Nuclear Information System (INIS)

    Gaffiney, E.

    2004-01-01

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1)

  13. Interactive Karyotyping Training

    Directory of Open Access Journals (Sweden)

    Ashwin Kotwaliwale

    2013-01-01

    Full Text Available Despite the wide use of newer techniques in genetic diagnostics, there remains a need for technologists to learn human chromosome morphology, identify abnormal metaphases and report clinical abnormalities. Global short age of cytogenetic trainers and a time consuming training process makes Karyotyping training difficult. We have developed a web based interactive Karyotyping training tool, KaryoTutor©, that allows technologists to learn karyotyping in an interactive environment and aids the trainer in the training process. KaryoTutor©provides visual clues for identifying abnormal chromosomes, provides instant test scores and includes a reference library of ideograms,sample chromosome images and reference materials. Trainees are able to recursively work on a case till a satisfactory result is achieved,with KaryoTutor providing interactive inputs.Additionally, trainers can assign cases and monitor trainee progress using audit trail management and other administrative features.

  14. Interactive Information Retrieval

    DEFF Research Database (Denmark)

    Borlund, Pia

    2013-01-01

    The paper introduces the research area of interactive information retrieval (IIR) from a historical point of view. Further, the focus here is on evaluation, because much research in IR deals with IR evaluation methodology due to the core research interest in IR performance, system interaction...... and satisfaction with retrieved information. In order to position IIR evaluation, the Cranfield model and the series of tests that led to the Cranfield model are outlined. Three iconic user-oriented studies and projects that all have contributed to how IIR is perceived and understood today are presented......: The MEDLARS test, the Book House fiction retrieval system, and the OKAPI project. On this basis the call for alternative IIR evaluation approaches motivated by the three revolutions (the cognitive, the relevance, and the interactive revolutions) put forward by Robertson & Hancock-Beaulieu (1992) is presented...

  15. Plasma-material interactions

    International Nuclear Information System (INIS)

    Wilson, K.L.

    1984-01-01

    Plasma-interactive components must be resistant to erosion processes, efficient in heat removal, and effective in minimizing tritium inventory and permeation. As long as plasma edge temperatures are 50 eV, no one material can satisfy the diverse requirements imposed by these plasma materials interactions. The only solution is the design of duplex, or even more complicated, structures. The material that faces the plasma should be low atomic number, with acceptable erosion and evaporation characteristics. The substrate material must have high thermal conductivity for heat removal. Finally, materials must be selected judiciously for tritium compatibility. In conclusion, materials play a critical role in the achievement of safe and economical magnetic fusion energy. Improvements in materials have already led to many advances in present day device operation, but additional innovative materials solutions are required for the critical plasma materials interaction issues in future power reactors

  16. Interactive Sample Book (ISB)

    DEFF Research Database (Denmark)

    Heimdal, Elisabeth Jacobsen; Lenau, Torben Anker; Guglielmi, Michel

    2009-01-01

    supervisor Torben A. Lenau. Inspiration to use smart materials Interactive textiles are still quite an unknown phenomenon to many. It is thus often difficult to communicate what kind of potentials lie within these materials. This is why the ISB project was started, as a practice based research project...... and senses in relation to integrated decoration and function primarily to indoor applications. The result of the project will be a number of interactive textiles, to be gathered in an interactive sample book (ISB), in a similar way as the sample books of wallpapers one can take home from the shop and choose...... from. In other words, it is a kind of display material, which in a simple manner can illustrate how different techniques and smart materials work. The sample book should display a number of possibilities where sensor technology, smart materials and textiles are mixed to such an extent that the textile...

  17. Interacting hot dark matter

    International Nuclear Information System (INIS)

    Atrio-Barandela, F.; Davidson, S.

    1997-01-01

    We discuss the viability of a light particle (∼30eV neutrino) with strong self-interactions as a dark matter candidate. The interaction prevents the neutrinos from free-streaming during the radiation-dominated regime so galaxy-sized density perturbations can survive. Smaller scale perturbations are damped due to neutrino diffusion. We calculate the power spectrum in the imperfect fluid approximation, and show that it is damped at the length scale one would estimate due to neutrino diffusion. The strength of the neutrino-neutrino coupling is only weakly constrained by observations, and could be chosen by fitting the power spectrum to the observed amplitude of matter density perturbations. The main shortcoming of our model is that interacting neutrinos cannot provide the dark matter in dwarf galaxies. copyright 1997 The American Physical Society

  18. Magnetic interactions through fluoride

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Sigrist, Marc; Weihe, Høgni

    2014-01-01

    support the parameter values and resolve |E| ≈ 0.04 cm(-1). The exchange coupling constant (J) is 1 order of magnitude smaller than that found in comparable systems with linear oxide bridging but comparable to typical magnitudes through cyanide, thus underlining the potential of fluoride complexes......The nature of the magnetic interaction through fluoride in a simple, dinuclear manganese(III) complex (1), bridged by a single fluoride ion in a perfectly linear fashion, is established by experiment and density functional theory. The magnitude of the antiferromagnetic exchange interaction...

  19. Alkane dimers interaction

    DEFF Research Database (Denmark)

    Ferrighi, Lara; Madsen, Georg Kent Hellerup; Hammer, Bjørk

    2010-01-01

    The interaction energies of a series of n-alkane dimers, from methane to decane, have been investigated with Density Functional Theory (DFT), using the MGGA-M06-L density functional. The results are compared both to the available wavefunction-based values as well as to dispersion corrected DFT...... values. The MGGA-M06-L density functional is a semi-local functional designed and has proven to provide accurate estimates of dispersion interactions for several systems at moderate computational cost. In the present application, it reproduces the trends obtained by the more expensive wavefunction...

  20. Urban Interaction Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Bermúdez, Juan Carlos Carvajal; Fernández, Manu

    This book is an effort to explore the newly emerging field of urban interaction design that addresses these issues. In the first part of the book, 'Foundations', we look into its origins. Where do its practitioners come from? How are they working together? What methodologies do they bring...... to the table? What are the key concepts they are addressing in their work? In the second part of the book named 'Trends', we go into current developments in the networked city and how urban interaction design as a field addresses these. Taken together, these sections will not give the definite definition...

  1. Mixed Interaction Spaces

    DEFF Research Database (Denmark)

    Lykke-Olesen, Andreas; Eriksson, E.; Hansen, T.R.

    In this paper, we describe a new interaction technique for mobile devices named Mixed Interaction Space that uses the camera of the mobile device to track the position, size and rotation of a fixed-point. In this demonstration we will present a system that uses a hand-drawn circle, colored object...... or a person’s face as a fixed-point to determine the location of the device. We use these features as a 4 dimensional input vector to a set of different applications....

  2. Interacting agegraphic dark energy

    International Nuclear Information System (INIS)

    Wei, Hao; Cai, Rong-Gen

    2009-01-01

    A new dark energy model, named ''agegraphic dark energy'', has been proposed recently, based on the so-called Karolyhazy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegraphic dark energy model and holographic dark energy model. The similarity and difference between agegraphic dark energy and holographic dark energy are also discussed. (orig.)

  3. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  4. Adhesive interactions with wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    While the chemistry for the polymerization of wood adhesives has been studied systematically and extensively, the critical aspects of the interaction of adhesives with wood are less clearly understood. General theories of bond formation need to be modified to take into account the porosity of wood and the ability of chemicals to be absorbed into the cell wall....

  5. Interactive Foresight Simulation

    DEFF Research Database (Denmark)

    Hansen, Mette Sanne; Rasmussen, Lauge Baungaard; Jacobsen, Peter

    2016-01-01

    The Combined Simulation Approach (CSA) is a way to evaluate risks and address potential unforeseen problems in a more interactive way than what is often observed in practice in companies or sectors. The approach is based on a combination of scenario analysis and discrete-event computer simulation...

  6. Interaction Before Agriculture

    DEFF Research Database (Denmark)

    Richter, Tobias; Garrard, Andrew; Allcock, Samantha

    2011-01-01

    This article discusses social interaction in the Epipalaeolithic of southwest Asia. Discussions of contact, social relationships and social organization have primarily focused on the Pre-Pottery Neolithic and are often considered to represent typical hallmarks of emergent farming societies. The h...

  7. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Lopes, Arminda; Ørngreen, Rikke

    . The papers reflect many different areas and address many complex and diverse work domains, ranging from medical user interfaces, work and speech interactions at elderly care facilities, greenhouse climate control, navigating through large oil industry engineering models, crisis management, library usability...

  8. Child Computer Interaction SIG

    DEFF Research Database (Denmark)

    Read, Janet; Hourcade, Juan Pablo; Markopoulos, Panos

    a mixture of facilitated creative thinking and a world café approach to bring the community together to tackle these two key challenges. The CCI SIG will be the natural meeting place for members of this community at CHI and will disseminate its discussion to the CCI and CHI communities through...... the production of visual and interactive materials at the CHI conference....

  9. Data Interactive Publications Revisited

    Science.gov (United States)

    Domenico, B.; Weber, W. J.

    2011-12-01

    A few years back, the authors presented examples of online documents that allowed the reader to interact directly with datasets, but there were limitations that restricted the interaction to specific desktop analysis and display tools that were not generally available to all readers of the documents. Recent advances in web service technology and related standards are making it possible to develop systems for publishing online documents that enable readers to access, analyze, and display the data discussed in the publication from the perspective and in the manner from which the author wants it to be represented. By clicking on embedded links, the reader accesses not only the usual textual information in a publication, but also data residing on a local or remote web server as well as a set of processing tools for analyzing and displaying the data. With the option of having the analysis and display processing provided on the server, there are now a broader set of possibilities on the client side where the reader can interact with the data via a thin web client, a rich desktop application, or a mobile platform "app." The presentation will outline the architecture of data interactive publications along with illustrative examples.

  10. Data Interactive Publications

    Science.gov (United States)

    Domenico, B.; Weber, J.

    2012-04-01

    For some years now, the authors have developed examples of online documents that allowed the reader to interact directly with datasets, but there were limitations that restricted the interaction to specific desktop analysis and display tools that were not generally available to all readers of the documents. Recent advances in web service technology and related standards are making it possible to develop systems for publishing online documents that enable readers to access, analyze, and display the data discussed in the publication from the perspective and in the manner from which the author wants it to be represented. By clicking on embedded links, the reader accesses not only the usual textual information in a publication, but also data residing on a local or remote web server as well as a set of processing tools for analyzing and displaying the data. With the option of having the analysis and display processing provided on the server (or in the cloud), there are now a broader set of possibilities on the client side where the reader can interact with the data via a thin web client, a rich desktop application, or a mobile platform "app." The presentation will outline the architecture of data interactive publications along with illustrative examples.

  11. Connectionist Interaction Information Retrieval.

    Science.gov (United States)

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  12. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, Marelene

    2005-01-01

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  13. Gaze interaction from bed

    DEFF Research Database (Denmark)

    Hansen, John Paulin; San Agustin, Javier; Jensen, Henrik Tomra Skovsgaard Hegner

    2011-01-01

    This paper presents a low-cost gaze tracking solution for bedbound people composed of free-ware tracking software and commodity hardware. Gaze interaction is done on a large wall-projected image, visible to all people present in the room. The hardware equipment leaves physical space free to assis...

  14. ROILA : RObot Interaction LAnguage

    NARCIS (Netherlands)

    Mubin, O.

    2011-01-01

    The number of robots in our society is increasing rapidly. The number of service robots that interact with everyday people already outnumbers industrial robots. The easiest way to communicate with these service robots, such as Roomba or Nao, would be natural speech. However, the limitations

  15. Empowered interaction through creativity

    DEFF Research Database (Denmark)

    Hasselblad, Stefan; Petersson, Eva; Brooks, Tony

    2007-01-01

    This paper reflects upon a case study where exploration, play and empowerment in interactive therapy sessions with audio and visual stimuli resulted in achievement, self-esteem and a shared pride between a young adult with profound and multiple learning disabilities (PMLD), his mother and the spe...

  16. Virtual Interactive Space (VIS)

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2015-01-01

    This paper shares code that enables the making of a Virtual Interactive Space (VIS) where the skin of the invisible active sensor area is dynamically responsive to the velocity of a limb e.g. hand. Used in proprioception training of movement the patch is at the core of the author’s Reafferentation...

  17. Dilations and interaction

    International Nuclear Information System (INIS)

    Buchholz, D.; Fredenhagen, K.

    1976-07-01

    As a consequence of the geometrical features of dilations massless particles do not interact in a local, dilationally invariant quantum theory. This result also holds in models in which dilations are only an asymptotically visible symmetry of the S-matrix. (orig.) [de

  18. Interaction with William Carnall

    International Nuclear Information System (INIS)

    Judd, Brian R.

    2005-01-01

    A personal account is given of interaction with William T. Carnall during the period 1977-1988, when I made regular visits to the Argonne National Laboratory to discuss the theoretical background to the spectroscopic work he was carrying out on the lanthanides and actinides

  19. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  20. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Lopes, Arminda; Ørngreen, Rikke

    This book constitutes the thoroughly refereed post-conference proceedings of the Third IFIP WG 13.6 Working Conference on Human Work Interaction Design, HWID 2012, held in Copenhagen, Denmark, in December 2012. The 16 revised papers presented were carefully selected for inclusion in this volume...

  1. Space for Interaction

    DEFF Research Database (Denmark)

    Jørgensen, Mariane Ellen; Folmer, Mette Blicher; Mullins, Michael

    SPACE FOR INTERACTION QUALIFYING GROUP TREATMENT FOR PATIENTS WITH CHRONIC PAIN THROUGH OPTIMIZATION(?) OF SPACE. A RANDOMIZED PILOT STUDY. In a Ph-D. Mariane Ellen Jørgensen / Nurse + psykoterapist / maej@rn.dk / Pain Center / Aalborg University Hospital / Denmark / Mette Blicher Folmer / Archit...

  2. Interactive Mold House Tour

    Science.gov (United States)

    Get a quick glimpse of some of the most important ways to protect your home from mold by this interactive tour of the Mold House. Room-by-room, you'll learn about common mold issues and how to address them.

  3. Teaching with Interactive Multimedia.

    Science.gov (United States)

    Hudson, Tim

    Based on the idea that anyone who is interested in making entertaining and informative presentations in educational settings is interested in multimedia, this practical guide offers tips for communication (and other) teachers who want to integrate and program interactive multimedia into their courses. The guide suggests that teachers on limited…

  4. Aesthetics of Mundane Interactions

    NARCIS (Netherlands)

    Vyas, Dhaval; Hassenzahl, M.

    2008-01-01

    John Dewey’s pragmatist aesthetics is used as a conceptual basis for designing new technologies that support staff-members’ mundane social interactions in an academic department. From this perspective, aesthetics is seen as a broader phenomenon that encompasses experiential aspects of staff-members’

  5. Aesthetics of Mundane Interactions

    OpenAIRE

    Vyas, Dhaval; Hassenzahl, M.

    2008-01-01

    John Dewey’s pragmatist aesthetics is used as a conceptual basis for designing new technologies that support staff-members’ mundane social interactions in an academic department. From this perspective, aesthetics is seen as a broader phenomenon that encompasses experiential aspects of staff-members’ everyday lives and not only a look-&-feel aspect.

  6. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Gonçalves, Frederica; Campos, Pedro; Clemmensen, Torkil

    2015-01-01

    In this paper, we review research in the emerging practice and research field of Human Work Interaction Design (HWID). We present a HWID frame-work, and a sample of 54 papers from workshops, conferences and journals from the period 2009-2014. We group the papers into six topical groups, and then ...

  7. Interactive Playgrounds for Children

    NARCIS (Netherlands)

    Poppe, Ronald Walter; van Delden, Robertus Wilhelmus; Moreno Celleri, Alejandro Manuel; Reidsma, Dennis; Nijholt, A.; Nijholt, Antinus

    Play is an important factor in the life of children. It plays a role in their cognitive, social, and physical development, and provides entertaining and fulfilling activities in itself. As with any field of human endeavor, interactive technology has a huge potential for transforming and enhancing

  8. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    is chapter explores patterns of repeated orientations to physical objects in interactants’ visuo-spatial and haptic surround. A number of examples are presented from advice-giving activities in various institutional settings, where participants-in-interaction initially draw on material objects...

  9. Exploring governmentality as interaction

    DEFF Research Database (Denmark)

    Fahnøe, Kristian

    from an interactionistic perspective, based on Goffman’s dramaturgy. The focal point is how Goffman's concepts of interaction order, rituals, role and role performance might be an point of entry for studying the techniques the self and the techniques of domination through which governmentality operates...

  10. Interactive Purchasing Situations

    NARCIS (Netherlands)

    Groote Schaarsberg, M.; Borm, P.E.M.; Hamers, H.J.M.; Reijnierse, J.H.

    2012-01-01

    Abstract: This paper introduces a new class of interactive cooperative purchasing situations and provides an explicit alternative characterization of the nucleolus of cooperative games, which offers an alternative to Kohlberg (1971). In our cooperative purchasing situation, the unit price of a

  11. Interactive shape metamorphosis

    Science.gov (United States)

    Chen, David T.; State, Andrei; Banks, David

    1994-01-01

    A technique for controlled metamorphosis between surfaces in 3-space is described. Well-understood techniques to produce shape metamorphosis between models in a 2D parametric space is applied. The user selects morphable features interactively, and the morphing process executes in real time on a high-performance graphics multicomputer.

  12. Tritium-surface interactions

    International Nuclear Information System (INIS)

    Kirkaldy, J.S.

    1983-06-01

    The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified

  13. A tabletop interactive storytelling system: designing for social interaction

    NARCIS (Netherlands)

    Alofs, Thijs; Theune, Mariet; Swartjes, I.M.T.

    This paper presents the Interactive Storyteller, a multi-user interface for AI-based interactive storytelling, where stories emerge from the interaction of human players with intelligent characters in a simulated story world. To support face-to-face contact and social interaction, we position users

  14. Interacting boson model with surface delta interaction between nucleons: Structure and interaction of bosons

    International Nuclear Information System (INIS)

    Druce, C.H.; Moszkowski, S.A.

    1986-01-01

    The surface delta interaction is used as an effective nucleon-nucleon interaction to investigate the structure and interaction of the bosons in the interacting boson model. We have obtained analytical expressions for the coefficients of a multipole expansion of the neutron-boson-proton-boson interaction for the case of degenerate orbits. A connection is made between these coefficients and the parameters of the interaction boson model Hamiltonian. A link between the latter parameters and the single boson energies is suggested

  15. Interacting boson model with surface delta interaction between nucleons: Structure and interaction of bosons

    Energy Technology Data Exchange (ETDEWEB)

    Druce, C.H.; Moszkowski, S.A.

    1986-01-01

    The surface delta interaction is used as an effective nucleon-nucleon interaction to investigate the structure and interaction of the bosons in the interacting boson model. We have obtained analytical expressions for the coefficients of a multipole expansion of the neutron-boson-proton-boson interaction for the case of degenerate orbits. A connection is made between these coefficients and the parameters of the interaction boson model Hamiltonian. A link between the latter parameters and the single boson energies is suggested.

  16. Quantity Estimation Of The Interactions

    International Nuclear Information System (INIS)

    Gorana, Agim; Malkaj, Partizan; Muda, Valbona

    2007-01-01

    In this paper we present some considerations about quantity estimations, regarding the range of interaction and the conservations laws in various types of interactions. Our estimations are done under classical and quantum point of view and have to do with the interaction's carriers, the radius, the influence range and the intensity of interactions

  17. Interaction Design for Public Spaces

    DEFF Research Database (Denmark)

    Kortbek, Karen Johanne

    2008-01-01

    In this abstract I describe the doctorial research project "Interaction Design for Public Spaces". The objective of the project is to explore and design interaction contexts in culture related public spaces such as museums, experience centres and festivals. As a perspective on this domain, I...... will focus on the usage of the body as an interaction device. Furthermore, the project will involve a dramaturgic take on communication and design of interactive systems in the pursuit of new ways to stage the interactive contexts. The outcome of the project will be guidelines and conceptual frameworks which...... will help interaction designers when designing for bodily movement, and communicating and staging interactive content in public spaces....

  18. Electron-positron interactions

    International Nuclear Information System (INIS)

    Wiik, B.; Wolf, G.

    1979-01-01

    This book is an introduction into the physics of electron-positron interactions. After a description of electron-positron storage rings pure electromagnetic e + e - interactions, and the total cross section are considered. Then low energy processes, the production of the J/psi and psi' particles including their radiative decay as well as the search for other narrow vector states are described. Then after the quark model interpretation of J/psi and psi' charmed mesons, the heavy lepton t, and the upsilon resonances are described. Thereafter inclusive hadron production and jet formation is discussed. Finally the next generation of e + e - colliding rings is described, and the first results from PETRA are presented. This book is suited for all physicists, who want to get a general review about e + e - physics. (HSI) 891 HSI/HSI 892 RKD

  19. Intelligent Interactive Multimedia

    CERN Document Server

    Watanabe, Toyohide; Takahashi, Naohisa; 5th International Conference on Intelligent Interactive Multimedia Systems and Services

    2012-01-01

    This volume contains the Proceedings of the 5th International Conference on Intelligent Interactive Multimedia Systems and Services (KES-IIMSS-12).  The Conference was jointly organised by Nagoya University in Japan and the KES International organisation, and held in the attractive city of Gifu.   The KES-IIMSS conference series, (series chairs Prof. Maria Virvou and Prof. George Tsihrintzis), presents novel research in various areas of intelligent multimedia system relevant to the development of a new generation of interactive, user-centric devices and systems.  The aim of the conference is to provide an internationally respected forum for scientific research in the technologies and applications of this new and dynamic research area.

  20. Interacting adiabatic quantum motor

    Science.gov (United States)

    Bruch, Anton; Kusminskiy, Silvia Viola; Refael, Gil; von Oppen, Felix

    2018-05-01

    We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

  1. Theory of fundamental interactions

    International Nuclear Information System (INIS)

    Pestov, A.B.

    1992-01-01

    In the present article the theory of fundamental interactions is derived in a systematic way from the first principles. In the developed theory there is no separation between space-time and internal gauge space. Main equations for basic fields are derived. In is shown that the theory satisfies the correspondence principle and gives rise to new notions in the considered region. In particular, the conclusion is made about the existence of particles which are characterized not only by the mass, spin, charge but also by the moment of inertia. These are rotating particles, the particles which represent the notion of the rigid body on the microscopical level and give the key for understanding strong interactions. The main concepts and dynamical laws for these particles are formulated. The basic principles of the theory may be examined experimentally not in the distant future. 29 refs

  2. Interactive design center.

    Energy Technology Data Exchange (ETDEWEB)

    Pomplun, Alan R. (Sandia National Laboratories, Livermore, CA)

    2005-07-01

    Sandia's advanced computing resources provide researchers, engineers and analysts with the ability to develop and render highly detailed large-scale models and simulations. To take full advantage of these multi-million data point visualizations, display systems with comparable pixel counts are needed. The Interactive Design Center (IDC) is a second generation visualization theater designed to meet this need. The main display integrates twenty-seven projectors in a 9-wide by 3-high array with a total display resolution of more than 35 million pixels. Six individual SmartBoard displays offer interactive capabilities that include on-screen annotation and touch panel control of the facility's display systems. This report details the design, implementation and operation of this innovative facility.

  3. Theory of gravitational interactions

    CERN Document Server

    Gasperini, Maurizio

    2017-01-01

    This is the second edition of a well-received book that is a modern, self-contained introduction to the theory of gravitational interactions. The new edition includes more details on gravitational waves of cosmological origin, the so-called brane world scenario, and gravitational time-delay effects. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field, while the second, more advanced part discusses the deep analogies (and differences) between a geometric theory of gravity and the “gauge” theories of the other fundamental interactions. This fills a gap within the traditional approach to general relativity which usually leaves students puzzled about the role of gravity. The required notions of differential geometry are reduced to the minimum, allowing room for aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational inter...

  4. Interactive Virtual Cinematography

    DEFF Research Database (Denmark)

    Burelli, Paolo

    is the process of visualising the content of a virtual environment by positioning and animating the virtual camera in the context of interactive applications such as a computer game. Camera placement and animation in games are usually directly controlled by the player or statically predened by designers. Direct...... control of the camera by the player increases the complexity of the interaction and reduces the designer's control on game storytelling. A completely designer-driven camera releases the player from the burden of controlling the point of view, but might generate undesired camera behaviours. Furthermore......, if the content of the game is procedurally generated, the designer might not have the necessary information to dene a priori the camera positions and movements. Automatic camera control aims to dene an abstraction layer that permits to control the camera using high-level and environment-independent rules...

  5. Student interaction in workshops

    DEFF Research Database (Denmark)

    Evers, Winie

    2014-01-01

    A kind of teaching for active learning has been experimented with at SDU Sønderborg as part of the course Supply Chain Dynamics. In this course the students learn about complex systems, system dynamics as well as supply chain instability and oscillation, the course lecturer invited the author...... to experiment with novel workshop methods and techniques, where objects are used to illustrate and model business issues (Heinemann et al, 2011, Buur et al, 2013). The idea was to see how students could be engaged in a different and more interactive way to learn about these topics, by assigning the students...... teaching should reflect this diversity by embracing and experimenting with multiple forms, including activation of students by students’ interaction and manipulation with objects....

  6. Embodying multilingual interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer; Mortensen, Janus

    this linguistic diversity is managed in situ by participants engaged in dialogue with one another, and what it is used for in these transient multilingual communities. This paper presents CA-based micro-ethnographic analyses of language choice in an informal social setting – a kitchen – of an international study...... literature on language choice in interaction, our findings emphasize that analyses of language choice in multilingual settings need to take into account social actions beyond the words that are spoken. We show that facial, spatial and postural configurations, gaze orientation and gestures as well as prosodic...... in the particular community of practice that we are investigating. Reference Hazel, Spencer, and Janus Mortensen. forthcoming. Kitchen talk: Exploring linguistic practices in liminal institutional interactions in a multilingual university setting. in Language Alternation, Language Choice, and Language Encounter...

  7. Interaction and Mindreading

    DEFF Research Database (Denmark)

    Michael, John Andrew

    2011-01-01

    In recent years, a number of theorists have developed approaches to social cognition that highlight the centrality of social interaction as opposed to mindreading (e.g. Gallagher and Zahavi 2008; Gallagher 2001, 2007, 2008; Hobson 2002; Reddy 2008; Hutto 2004; De Jaegher 2009; De Jaegher and Di...... Paolo 2007; Fuchs and De Jaegher 2009; De Jaegher, Di Paolo and Gallagher 2010). There are important differences among these approaches, as I will discuss, but they are united by their commitment to the claim that various embodied and extended processes sustain social understanding and interaction...... will give reasons for being skeptical about. I will then present an alternative and moderate version of interactionism, according to which the embodied and extended processes that interactionists emphasize actually complement mindreading and may even contribute as an input to mindreading....

  8. Interactive Information Retrieval:

    DEFF Research Database (Denmark)

    Borlund, Pia

    IIR from the perspective of search dedication and task load in order to also include everyday life information seeking? With this presentation, the IIR community is invited to an exchange of ideas and is encouraged to engage in collaborations with the solving of these (and other) issues to our joint......This presentation addresses methodological issues of interactive information retrieval (IIR) evaluation in terms of what it entails to study users' use and interaction with IR systems, as well as their satisfaction with retrieved information. In particular, the presentation focuses on test design...... of the users to ensure a complete and realistic picture to enhance our understanding of IIR. The presentation also reflects on whether a re-thinking of the concept on an information need is necessary. One may ask whether it still makes sense to talk about types of information needs. Or should we rather study...

  9. 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

  10. Interactive protein manipulation

    Energy Technology Data Exchange (ETDEWEB)

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  11. Strongly interacting Higgs bosons

    International Nuclear Information System (INIS)

    Appelquist, T.; Bernard, C.

    1980-01-01

    The sensitivity of present-energy weak interactions to a strongly interacting heavy-Higgs-boson sector is discussed. The gauged nonlinear sigma model, which is the limit of the linear model as the Higgs-boson mass goes to infinity, is used to organize and catalogue all possible heavy-Higgs-boson effects. As long as the SU(2)/sub L/ x SU(2)/sub R/ symmetry of the Higgs sector is preserved, these effects are found to be small, of the order of the square of the gauge coupling times logarithms (but not powers) of the Higgs-boson mass divided by the W mass. We work in the context of a simplified model with gauge group SU(2)/sub L/; the extension to SU(2)/sub L/ x U(1) is briefly discussed

  12. Wood–water interactions

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance...... therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one...... must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water...

  13. Interactive protein manipulation

    International Nuclear Information System (INIS)

    2003-01-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures

  14. Electron: Cluster interactions

    International Nuclear Information System (INIS)

    Scheidemann, A.A.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E ∼ 0.1 to E ∼ 6 eV. The investigation focused on the closed shell clusters Na 8 , Na 20 , Na 40 . The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size

  15. Investigating Molecular Interactions

    DEFF Research Database (Denmark)

    Clausen, Henrik Fanø

    2010-01-01

    ···π interactions are accommodated by electrostatic complementarity. The crystal structure of both the α- and the β-polymorph of hydroquinone is presented in Chapter 6 with focus on close intermolecular contacts between the molecules via Hirshfeld surface analysis. The charge density distribution of the empty β....... The last chapter of this dissertation presents the analysis of intermolecular interaction using both the Hirshfeld surface and charge density distribution of the acetonitrile β-hydroquinone clathrate. The local packing and related close contacts are examined by breakdown of the fingerprint plots revealing......, are also introduced, as a goal of the analysis of charge density distributions is to obtain further understanding of these macroscopic properties. Neutron diffraction will be used as a complementary tool to the X-ray diffraction experiment, as positional and thermal parameters of hydrogen atoms can...

  16. INTERACTIVE LEARNING: ADVANTAGES AND DISADVANTAGES

    Directory of Open Access Journals (Sweden)

    O. Kustovska

    2016-10-01

    Full Text Available In the article the use of interactive technologies in the educational process of the university, allowing students to develop innovative thinking, away from stereotypes, develop imagination, communication skills and expertise, intellectual, emotional, motivational and other areas of personality. Implementing the principles of technological learning, interactive educational technology and provides interactive computer learning tools, and interactivity of educational process when the basic conceptual provisions defined training based on interactive communication.

  17. Interactions of light gravitinos

    International Nuclear Information System (INIS)

    Clark, T.E.; Lee, T.; Love, S.T.; Wu, G.

    1998-01-01

    In models of spontaneously broken supersymmetry, certain light gravitino processes are governed by the coupling of their Goldstino components. The rules for constructing SUSY and gauge invariant actions involving the Goldstino couplings to matter and gauge fields are presented. The explicit operator construction is found to be at variance with some previously reported claims. A phenomenological consequence arising from light gravitino interactions in supernova is reexamined and scrutinized. copyright 1998 The American Physical Society

  18. Noncovalent interactions in biochemistry

    Czech Academy of Sciences Publication Activity Database

    Riley, Kevin Eugene; Hobza, Pavel

    2011-01-01

    Roč. 1, č. 1 (2011), s. 3-17 ISSN 1759-0876 R&D Projects: GA MŠk LC512 Grant - others:NSF EPSCORE(US) EPS-0701525; Korea Science and Engineering Foundation(KR) R32-2008-000-10180-0 Institutional research plan: CEZ:AV0Z40550506 Keywords : noncovalent interactions * WFT calculations * DFT calculations * applications Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Model Checking Feature Interactions

    DEFF Research Database (Denmark)

    Le Guilly, Thibaut; Olsen, Petur; Pedersen, Thomas

    2015-01-01

    This paper presents an offline approach to analyzing feature interactions in embedded systems. The approach consists of a systematic process to gather the necessary information about system components and their models. The model is first specified in terms of predicates, before being refined to t...... to timed automata. The consistency of the model is verified at different development stages, and the correct linkage between the predicates and their semantic model is checked. The approach is illustrated on a use case from home automation....

  20. Interactive videodisc in maintenance

    International Nuclear Information System (INIS)

    Zwingelstein, G.; Nguyen Van Nghi, B.

    1986-01-01

    After a recall of the videodisc characteristics, this paper presents its utilization by Electricite de France in the framework of training and maintenance. The SICMA (Interactive Communication System in Maintenance) developed and tested by Electricte de France is presented as also its utilization. It has been tested on the sites of Dampierre and Paluel in the cases of training and maintenance (deconnexion of drive rods of control elements); the conclusions of this experimentation are finally given. 4 refs [fr

  1. Interactive Mathematics Textbooks

    DEFF Research Database (Denmark)

    Sinclair, Robert

    1999-01-01

    We claim that important considerations have been overlooked in designinginteractive mathematics educational software in the past.In particular,most previous work has concentrated on how to make use ofpre-existing software in mathematics education, rather than firstasking the more...... fundamentalquestion of which requirements mathematics education puts on software, and thendesigning software to fulfil these requirements.We present a working prototype system which takes a script defining an interactivemathematicaldocument and then provides a reader with an interactive realization of thatdocument....

  2. Between autonomy and interaction

    DEFF Research Database (Denmark)

    Verwohlt, Betina

    In 2007, a smoking law was implemented in Denmark, banning indoor tobacco smoke in public places such as pubs, restaurants, workplaces, public offices, hospitals and shopping malls. The law marks a paradigm shift in Danish tobacco policy manifesting a stronger structural focus than has been the c...... attitudes towards structural initiatives before and after the implementation and discusses what causes changes in the population’s attitudes and whether the attitudes are best described as autonomous or as interactive with societal changes....

  3. SEEPAGE/INVERT INTERACTIONS

    International Nuclear Information System (INIS)

    P.S. Domski

    2000-01-01

    As directed by a written development plan (CRWMS M andO 1999a), a conceptual model for water entering the drift and reacting with the invert materials is to be developed. The purpose of this conceptual model is to assist Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction, and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE), Revision 2 (NRC 1999). This AMR also seeks to: (1) Develop a logical conceptual model for physical/chemical interactions between seepage and the invert materials; (2) screen potential processes and reactions that may occur between seepage and invert to evaluate the potential consequences of the interactions; and (3) outline how seepage/invert processes may be quantified. This document provides the conceptual framework for screening out insignificant processes and for identifying and evaluating those seepage/invert interactions that have the potential to be important to subsequent PAO analyses including the Engineered Barrier System (EBS) physical and chemical model abstraction effort. This model has been developed to serve as a basis for the in-drift geochemical analyses performed by PAO. Additionally, the concepts discussed within this report may also apply to certain near and far-field geochemical processes and may have conceptual application within the unsaturated zone (UZ) and saturated zone (SZ) transport modeling efforts. The seepage/invert interactions will not directly affect any principal factors

  4. Rhythmic interaction in VR

    DEFF Research Database (Denmark)

    Erkut, Cumhur

    2017-01-01

    Cinematic virtual reality is a new and relatively unexplored area in academia. While research in guiding the spectator's attention in this new medium has been conducted for some time, a focus on editing in conjunction with spectator orientation is only currently emerging. In this paper, we consid...... in rhythm perception, and complement it with applications in traditional editing. Through the notion of multimodal listening we provide guidelines that can be used in rhythmic and sonic interaction design in VR....

  5. Interactions faibles en harmonie

    CERN Multimedia

    1978-01-01

    Des résultats de haute précision obtenus à Stanford ouvrent la voie vers une unification des interactions faible et électromagnétique ; Présentation à la Conférence neutrino d'Oxford de nouveaux résultats en accord avec la théorie de la synthèse des forces faible et électro- magnétique

  6. Budgeted Interactive Learning

    Science.gov (United States)

    2017-06-15

    2, and 3). The selection scheme is implemented and released as an open-source active learning package. They have studied theories for designing...We have studied theories for designing algorithms for interactive learning with batch-like feedback (for 1) and algorithms for online digestion of... necessity on pre-training. The new idea provides layer-wise cost estimation with auxiliary nodes, and is applicable to a wider range of deep learning

  7. Strong interaction phenomenology

    International Nuclear Information System (INIS)

    Giffon, M.

    1989-01-01

    A brief review of high energy hadronic data (Part I)is followed by an introduction to the standard (Weinberg Salam Glashow) model of electroweak interactions and its extension to the hadrons (Part II). Rudiments of QCD and of the parton model area given in Part III together with a quick review of the spectroscopy of heavy flavours whereas Part IV is devoted to the introduction to deep inelastic scattering and to the so-called EMC effects. (author)

  8. Interacting warm dark matter

    International Nuclear Information System (INIS)

    Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo

    2013-01-01

    We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ m α ρ e β form, where ρ m and ρ e are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w m and w e of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used

  9. Interactive tabletops in education

    OpenAIRE

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications also witnesses the growing importance of face-to-face collaboration in CSCL and acknowledges the physicality of learnin...

  10. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  11. Pharmacological interactions of vasoconstrictors.

    Science.gov (United States)

    Gómez-Moreno, Gerardo; Guardia, Javier; Cutando, Antonio; Calvo-Guirado, José Luis

    2009-01-01

    This article is the first of a series on pharmacological interactions involving medicaments commonly prescribed and/or used in odontology: vasoconstrictors in local anaesthetics and anti-inflammatory and anti-microbial analgesics. The necessity for the odontologist to be aware of adverse reactions as a result of the pharmacological interactions is due to the increase in medicament consumption by the general population. There is a demographic change with greater life expectancy and patients have increased chronic health problems and therefore have increased medicament intake. The presence of adrenaline (epinephrine) and other vasoconstrictors in local odontological anaesthetics is beneficial in relation to the duration and depth of anaesthesia and reduces bleeding and systemic toxicity of the local anaesthetic. However, it might produce pharmacological interactions between the injected vasoconstrictors and the local anaesthetic and adrenergic medicament administered exogenically which the odontologist should be aware of, especially because of the risk of consequent adverse reactions. Therefore the importance of conducting a detailed clinical history of the general state of health and include all medicaments, legal as well as illegal, taken by the patient.

  12. DRUG INTERACTIONS WITH DIAZEPAM

    Directory of Open Access Journals (Sweden)

    Zoran Bojanić

    2011-06-01

    Full Text Available Diazepam is a benzodiazepine derivative with anxyolitic, anticonvulsant, hypnotic, sedative, skeletal muscle relaxant, antitremor, and amnestic activity. It is metabolized in the liver by the cytochrome P (CYP 450 enzyme system. Diazepam is N-demethylated by CYP3A4 and CYP2C19 to the active metabolite N-desmethyldiazepam, and is hydroxylated by CYP3A4 to the active metabolite temazepam. N-desmethyl-diazepam and temazepam are both further metabolized to oxazepam. Concomitant intake of inhibitors or inducers of the CYP isozymes involved in the biotransformation of diazepam may alter plasma concentrations of this drug, although this effect is unlikely to be associated with clinically relevant interactions.The goal of this article was to review the current literature on clinically relevant pharmacokinetic drug interactions with diazepam.A search of MEDLINE and EMBASE was conducted for original research and review articles published in English between January 1971. and May 2011. Among the search terms were drug interactions, diazepam, pharmacokinetics, drug metabolism, and cytochrome P450. Only articles published in peer-reviewed journals were included, and meeting abstracts were excluded. The reference lists of relevant articles were hand-searched for additional publications.Diazepam is substantially sorbed by the plastics in flexible containers, volume control set chambers, and tubings of intravenous administration sets. Manufacturers recommend not mixing with any other drug or solution in syringe or solution, although diazepam is compatible in syringe with cimetidine and ranitidine, and in Y-site with cisatracurium, dobutamine, fentanyl, hydromorphone, methadone, morphine, nafcillin, quinidine gluconate, remifentanil, and sufentanil. Diazepam is compatible with: dextrose 5% in water, Ringers injection, Ringers injection lactated and sodium chloride 0.9%. Emulsified diazepam is compatible with Intralipid and Nutralipid.Diazepam has low potential

  13. Intelligently interactive combat simulation

    Science.gov (United States)

    Fogel, Lawrence J.; Porto, Vincent W.; Alexander, Steven M.

    2001-09-01

    To be fully effective, combat simulation must include an intelligently interactive enemy... one that can be calibrated. But human operated combat simulations are uncalibratable, for we learn during the engagement, there's no average enemy, and we cannot replicate their culture/personality. Rule-based combat simulations (expert systems) are not interactive. They do not take advantage of unexpected mistakes, learn, innovate, and reflect the changing mission/situation. And it is presumed that the enemy does not have a copy of the rules, that the available experts are good enough, that they know why they did what they did, that their combat experience provides a sufficient sample and that we know how to combine the rules offered by differing experts. Indeed, expert systems become increasingly complex, costly to develop, and brittle. They have face validity but may be misleading. In contrast, intelligently interactive combat simulation is purpose- driven. Each player is given a well-defined mission, reference to the available weapons/platforms, their dynamics, and the sensed environment. Optimal tactics are discovered online and in real-time by simulating phenotypic evolution in fast time. The initial behaviors are generated randomly or include hints. The process then learns without instruction. The Valuated State Space Approach provides a convenient way to represent any purpose/mission. Evolutionary programming searches the domain of possible tactics in a highly efficient manner. Coupled together, these provide a basis for cruise missile mission planning, and for driving tank warfare simulation. This approach is now being explored to benefit Air Force simulations by a shell that can enhance the original simulation.

  14. Interactive Learning and "Clickers"

    Science.gov (United States)

    Rudolph, Alexander

    2006-12-01

    A growing body of evidence demonstrates that student understanding and retention of key concepts in science can be dramatically improved by using “Interactive Learning” techniques. Interactive learning is a way to get students more actively involved in their own learning than by simple lecture alone. I will focus on one type of interactive learning activity, known as “Think-Pair-Share”. After a brief (10-20 minute) lecture on a topic, students are asked a conceptually challenging multiple-choice question. After they answer, if there is sufficient disagreement, the students discuss the question in small groups after which they answer the same question again. Frequently, the percentage of correct answers goes up, indicating that the active role of speaking and listening, together with peer instruction, has helped students better grasp the concept being tested. If disagreement persists, or if students continue to have questions, a short, class-wide discussion can be held. Clickers provide an excellent means to collect students’ answers to “Think-Pair-Share” questions in real time. Although clickers are not essential, they do provide some advantages over alternatives such as flash cards: answers are completely anonymous (though you as instructor can record individual responses); you can display a histogram of results immediately, either before or after group discussion, providing immediate feedback; by recording the results, you can give students credit for their participation in class. In this talk, I will model “Think-Pair-Share” with the audience using clickers, show results from my classes before and after group discussions, share results of a student survey on “Think-Pair-Share” and clickers, describe other uses of clickers (e.g., taking attendance, surveys, test administration) and highlight some of the pros and cons of clickers v. flashcards.

  15. Flavivirus-Mosquito Interactions

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  16. Bunyavirus-Vector Interactions

    Directory of Open Access Journals (Sweden)

    Kate McElroy Horne

    2014-11-01

    Full Text Available The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family.

  17. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, M.

    2010-01-01

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  18. The interacting boson model

    International Nuclear Information System (INIS)

    Iachello, F.; Arima, A.

    1987-01-01

    The book gives an account of some of the properties of the interacting boson model. The model was introduced in 1974 to describe in a unified way the collective properties of nuclei. The book presents the mathematical techniques used to analyse the structure of the model. The mathematical framework of the model is discussed in detail. The book also contains all the formulae that have been developed throughout the years to account for collective properties of nuclei. These formulae can be used by experimentalists to compare their data with the predictions of the model. (U.K.)

  19. Interactive virtual optical laboratories

    Science.gov (United States)

    Liu, Xuan; Yang, Yi

    2017-08-01

    Laboratory experiences are essential for optics education. However, college students have limited access to advanced optical equipment that is generally expensive and complicated. Hence there is a need for innovative solutions to expose students to advanced optics laboratories. Here we describe a novel approach, interactive virtual optical laboratory (IVOL) that allows unlimited number of students to participate the lab session remotely through internet, to improve laboratory education in photonics. Although students are not physically conducting the experiment, IVOL is designed to engage students, by actively involving students in the decision making process throughout the experiment.

  20. Alecto 2 - interaction studies

    International Nuclear Information System (INIS)

    Brunet, J.P.; Clouet d'Orval, Ch.; Mougniot, J.C.; Penet, F.

    1965-01-01

    Weak interactions were experimentally studies with the tank of the critical assembly Alecto II and one, two or three bottles containing solutions of various concentrations. In particular, was studied the validity of certain classical assumptions, shielding effects, screening and semi-reflexion effects, importance of thermal coupling. The method of the 'k eff , solid angle' is shown to apply to such a system. The determination by divergence and pulsed neutron technique of the reactivity related to a millimeter of solution level affords the obtention of critical heights in terms of reactivity. (authors) [fr

  1. 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

  2. Visuo-Vestibular Interactions

    Science.gov (United States)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  3. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  4. Herb-drug interactions.

    Science.gov (United States)

    Fugh-Berman, A

    2000-01-08

    Concurrent use of herbs may mimic, magnify, or oppose the effect of drugs. Plausible cases of herb-drug interactions include: bleeding when warfarin is combined with ginkgo (Ginkgo biloba), garlic (Allium sativum), dong quai (Angelica sinensis), or danshen (Salvia miltiorrhiza); mild serotonin syndrome in patients who mix St John's wort (Hypericum perforatum) with serotonin-reuptake inhibitors; decreased bioavailability of digoxin, theophylline, cyclosporin, and phenprocoumon when these drugs are combined with St John's wort; induction of mania in depressed patients who mix antidepressants and Panax ginseng; exacerbation of extrapyramidal effects with neuroleptic drugs and betel nut (Areca catechu); increased risk of hypertension when tricyclic antidepressants are combined with yohimbine (Pausinystalia yohimbe); potentiation of oral and topical corticosteroids by liquorice (Glycyrrhiza glabra); decreased blood concentrations of prednisolone when taken with the Chinese herbal product xaio chai hu tang (sho-salko-to); and decreased concentrations of phenytoin when combined with the Ayurvedic syrup shankhapushpi. Anthranoid-containing plants (including senna [Cassia senna] and cascara [Rhamnus purshiana]) and soluble fibres (including guar gum and psyllium) can decrease the absorption of drugs. Many reports of herb-drug interactions are sketchy and lack laboratory analysis of suspect preparations. Health-care practitioners should caution patients against mixing herbs and pharmaceutical drugs.

  5. Electromagnetic Interactions of Muons

    CERN Multimedia

    2002-01-01

    This experiment was the first in a programme of physics experiments with high-energy muons using a large spectrometer facility. The aim of this experiment is to study the inelastic scattering of muons with various targets to try to understand better the physics of virtual photon interactions over a wide range of four-momentum transfer (q$^{2}$).\\\\ \\\\ The spectrometer includes a large aperture dipole magnet (2m x 1m) of bending power $\\simeq$5 T.m and a magnetized iron filter to distinguish the scattered muons from hadrons. Drift chambers and MWPC are used before and after the magnet to detect charged products of the interaction and to allow a momentum determination of the scattered muon to an accuracy of $\\simeq$at 100 GeV/c, and an angular definition of $\\pm$ 0.1 mrad. The triggering on scattered muons relies on three planes of scintillation counter hodoscopes before and after the magnetized iron, whose magnetic field serves to eliminate triggers from low momentum muons which are produced copiously by pion d...

  6. State of electroweak interactions

    International Nuclear Information System (INIS)

    Lane, K.

    1984-01-01

    I assess what we know and what we do not know about the electroweak interactions. In particular, I argue that existing data on the electroweak parameters rho, sin 2 theta/sub w/ and G/sub F/ and on the recently discovered W +- and Z 0 allow us reasonably to conclude that: (1) the W +- and Z 0 truly are the elementary massive gauge bosons of SU(2) x U(1) and not the composite bosons of a new strong interaction, and (2) the electroweak scalar sector consists of weak doublets only. The most important thing we do not know is everything else about the electroweak scalar sector. In the hope of soon shedding light on this issue, a new method of searching for electroweak scalars in existing p-barp colliders is proposed. The basis of this method is that the branching ratio of W +- to decay to a charged plus a neutral scalar (expected in non-minimal SU(2) x U(1) models) can be as large as 1-2%, with detectable rates up to scalar masses of approx.35 GeV

  7. Interactive fundamental physics

    International Nuclear Information System (INIS)

    Rubin, E.L.

    1992-01-01

    THE REAL STUFF is an Expanded Media Physics Course aimed at students still in the formative early years of secondary school. Its consists of a working script for an interactive multimedia study unit in basic concepts of physics. The unit begins with a prologue on the Big Bang that sets the stage, and concludes with a lesson on Newton's first law of motion. The format is interactive, placing the individual student in control of a layered ''hypermedia'' structure that enables him or her to find a level of detail and difficulty that is comfortable and meaningful. The intent is to make physics relevant, intellectually accessible and fun. On-screen presenters and demonstrators will be females and males of various ages, ethnicities and backgrounds, and will include celebrities and physicists of note. A lean, layered design encourages repeated, cumulative study and makes the material useful for self-directed Teaming even by college students. THE REAL STUFF introduces a new science teaching paradigm, a way to teach science that will engage even students who have ''declined'' to be interested in science in the past. Increased participation in science by women, African-Americans and Spanish-speaking students is a particular goal

  8. Hydrogen-antihydrogen interactions

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Carr, J.M.

    1998-01-01

    A small number of antihydrogen (AH) atoms have recently been prepared at CERN and at Fermilab. However, these atoms were travelling at speeds close to that of light. It is intended to carry out experiments on AH by trapping it at very low temperature ( 2 and He with energies up to room temperature. However, these reactions are not easy to treat theoretically. In this paper we consider the interaction between AH and H. This has already received some attention. Initially, in a collision between AH and H the electron is bound to the proton and the positron is bound to the antiproton. Clearly, if the proton and antiproton coincide they cannot bind the two light particles. There exists a critical value, R c , of the internuclear distance, probably not very much below a 0 , below which the electron and the positron can attain a lower energy by separating from the nuclei and forming positronium. As a first stage in our work on the H-AH interaction, we are carrying out variational calculations of the energy of the H-AH system for internuclear separations a short distance above R c . The aim is to determine R c as accurately as possible. The basis set used is similar to that of a previous calculation by W. Kolos, D.L. Morgan, D.M. Schrader, L. Wolniewiez (1975). However, it also contains a function to represent weakly bound positronium. Initial results suggest that R c 0 . (orig.)

  9. New particles and interactions

    International Nuclear Information System (INIS)

    Gilman, F.J.; Grannis, P.D.

    1984-04-01

    The Working Group on New Particles and Interactions met as a whole at the beginning and at the end of the Workshop. However, much of what was accomplished was done in five subgroups. These were devoted to: (1) new quarks and leptons; (2) technicolor; (3) supersymmetry; (4) rare decays and CP; and (5) substructure of quarks and leptons. Other aspects of new particles, e.g., Higgs, W', Z', fell to the Electroweak Working Group to consider. The central question of this Workshop of comparing anti pp (with L = 10 32 /cm 2 -sec) with pp (with L = 10 33 /cm 2 -sec) colliders carried through to all these subgroups. In addition there were several other aspects of hadron colliders which were considered: what does an increase in √s gain in cross section and resultant sensitivity to new physics versus an increase in luminosity; will polarized beams or the use of asymmetries be essential in finding new interactions; where and at what level do rate limitations due to triggering or detection systems play a role; and how and where will the detection of particles with short, but detectable, lifetimes be important. 25 references

  10. Genetic and environmental interactions

    International Nuclear Information System (INIS)

    Strong, L.C.

    1977-01-01

    Cancer may result from a multistage process occurring over a long period of time. Presumably, initial and progressive stages of carcinogenesis may be modified by both genetic and environmental factors. Theoretically, genetic factors may alter susceptibility to the carcinogenic effects of an environmental agent at the initial exposure due to variation in metabolism of the carcinogen or variation in specific target cell response to the active carcinogen, or during the latent phase due to numerous factors that might increase the probability of tumor expression, including growth-promoting factors or immunodeficiency states. Observed genetic and environmental interactions in carcinogenesis include an association between genetically determined inducibility of aryl hydrocarbon hydroxylase and smoking-related cancers, familial susceptibility to certain environmental carcinogens, an association between hereditary disorders of mutagenesis and carcinogenesis, and enhancement of tissue-specific, dominantly inherited tumor predisposition by radiation. Multiple primary tumors occur frequently in genetically predisposed individuals. Specific markers for susceptibility must be sought in order that high-risk individuals be identified and appropriate measures taken for early cancer detection or prevention. Study of the nature of the genetically determined susceptibility and interactions with environmental agents may be revealing in the understanding of carcinogenesis in general

  11. Laser-induced interactions

    International Nuclear Information System (INIS)

    Green, W.R.

    1979-01-01

    This dissertation discusses some of the new ways that lasers can be used to control the energy flow in a medium. Experimental and theoretical considerations of the laser-induced collision are discussed. The laser-induced collision is a process in which a laser is used to selectively transfer energy from a state in one atomic or molecular species to another state in a different species. The first experimental demonstration of this process is described, along with later experiments in which lasers were used to create collisional cross sections as large as 10 - 13 cm 2 . Laser-induced collisions utilizing both a dipole-dipole interaction and dipole-quadrupole interaction have been experimentally demonstrated. The theoretical aspects of other related processes such as laser-induced spin-exchange, collision induced Raman emission, and laser-induced charge transfer are discussed. Experimental systems that could be used to demonstrate these various processes are presented. An experiment which produced an inversion of the resonance line of an ion by optical pumping of the neutral atom is described. This type of scheme has been proposed as a possible method for constructing VUV and x-ray lasers

  12. Interactive Terascale Particle Visualization

    Science.gov (United States)

    Ellsworth, David; Green, Bryan; Moran, Patrick

    2004-01-01

    This paper describes the methods used to produce an interactive visualization of a 2 TB computational fluid dynamics (CFD) data set using particle tracing (streaklines). We use the method introduced by Bruckschen et al. [2001] that pre-computes a large number of particles, stores them on disk using a space-filling curve ordering that minimizes seeks, and then retrieves and displays the particles according to the user's command. We describe how the particle computation can be performed using a PC cluster, how the algorithm can be adapted to work with a multi-block curvilinear mesh, and how the out-of-core visualization can be scaled to 296 billion particles while still achieving interactive performance on PG hardware. Compared to the earlier work, our data set size and total number of particles are an order of magnitude larger. We also describe a new compression technique that allows the lossless compression of the particles by 41% and speeds the particle retrieval by about 30%.

  13. Nucleon-antinucleon interaction

    International Nuclear Information System (INIS)

    Dover, C.B.

    1983-01-01

    The current status of our understanding of the low energy nucleon-antinucleon (N anti N) interaction is reviewed. We compare several phenomenological models which fit the available N anti N cross section data. The more realistic of these models employ an annihilation potential W(r) which is spin, isospin and energy dependent. The microscopic origins for these dependences are discussed in terms of quark rearrangement and annihilation processes. It is argued that the study of N anti N annihilation offers a powerful means of studying quark dynamics at short distances. We also discuss how one may try to isolate coherent meson exchange contributions to the medium and long range part of the N anti N potential. These pieces of the N anti N interaction are calculable via the G-parity transformation from a model for the NN potential; their effects are predicted to be seen in N anti N spin observables, to be measured at LEAR. The possible existence of quasi-stable bound states or resonances of the anti N plus one or more nucleons is discussed, with emphasis on few-body systems. 42 references

  14. Interactive Computer Graphics

    Science.gov (United States)

    Kenwright, David

    2000-01-01

    Aerospace data analysis tools that significantly reduce the time and effort needed to analyze large-scale computational fluid dynamics simulations have emerged this year. The current approach for most postprocessing and visualization work is to explore the 3D flow simulations with one of a dozen or so interactive tools. While effective for analyzing small data sets, this approach becomes extremely time consuming when working with data sets larger than one gigabyte. An active area of research this year has been the development of data mining tools that automatically search through gigabyte data sets and extract the salient features with little or no human intervention. With these so-called feature extraction tools, engineers are spared the tedious task of manually exploring huge amounts of data to find the important flow phenomena. The software tools identify features such as vortex cores, shocks, separation and attachment lines, recirculation bubbles, and boundary layers. Some of these features can be extracted in a few seconds; others take minutes to hours on extremely large data sets. The analysis can be performed off-line in a batch process, either during or following the supercomputer simulations. These computations have to be performed only once, because the feature extraction programs search the entire data set and find every occurrence of the phenomena being sought. Because the important questions about the data are being answered automatically, interactivity is less critical than it is with traditional approaches.

  15. Interacting composite fermions

    DEFF Research Database (Denmark)

    nrc762, nrc762

    2016-01-01

    Numerical studies by Wójs, Yi, and Quinn have suggested that an unconventional fractional quantum Hall effect is plausible at filling factors ν=1/3 and 1/5, provided the interparticle interaction has an unusual form for which the energy of two fermions in the relative angular momentum three channel...... as fractional quantum Hall effect of electrons at ν=4/11, 4/13, 5/13, and 5/17. I investigate in this article the nature of the fractional quantum Hall states at ν=4/5, 5/7, 6/17, and 6/7, which correspond to composite fermions at ν∗=4/3, 5/3, and 6/5, and find that all these fractional quantum Hall states...... are conventional. The underlying reason is that the interaction between composite fermions depends substantially on both the number and the direction of the vortices attached to the electrons. I also study in detail the states with different spin polarizations at 6/17 and 6/7 and predict the critical Zeeman...

  16. Vehicle track interaction safety standards

    Science.gov (United States)

    2014-04-02

    Vehicle/Track Interaction (VTI) Safety Standards aim to : reduce the risk of derailments and other accidents attributable : to the dynamic interaction between moving vehicles and the : track over which they operate. On March 13, 2013, the Federal : R...

  17. 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

  18. Multimodal Embodied Mimicry in Interaction

    NARCIS (Netherlands)

    Sun, X.; Esposito, Anna; Vinciarelli, Alessandro; Vicsi, Klára; Pelachaud, Catherine; Nijholt, Antinus

    2011-01-01

    Nonverbal behaviors play an important role in communicating with others. One particular kind of nonverbal interaction behavior is mimicry. It has been argued that behavioral mimicry supports harmonious relationships in social interaction through creating affiliation, rapport, and liking between

  19. Design Principles for Interactive Software

    DEFF Research Database (Denmark)

    The book addresses the crucial intersection of human-computer interaction (HCI) and software engineering by asking both what users require from interactive systems and what developers need to produce well-engineered software. Needs are expressed as...

  20. Nuclear physics and fundamental interactions

    International Nuclear Information System (INIS)

    Krmpotic, K.

    1980-01-01

    In this work, it is discussed strong, weak and electromagnetic interactions. By means of experiments and theoretical interpretation of these interactions it was possible to interpret important properties, which will be discussed here. (A.C.A.S.) [pt

  1. Interactive lectures in engineering education

    NARCIS (Netherlands)

    van Dijk, L.A.; van den Berg, G.C.; van Keulen, H.

    2001-01-01

    This article discusses an alternative approach to lecturing: the interactive lecture. In the literature, interactive teaching is forwarded as a means to increase the effectiveness of lectures. Members of lecturing staff still seem, however, reluctant to incorporate interactive teaching in their

  2. SNP interaction pattern identifier (SIPI)

    DEFF Research Database (Denmark)

    Lin, Hui Yi; Chen, Dung Tsa; Huang, Po Yu

    2017-01-01

    Motivation: Testing SNP-SNP interactions is considered as a key for overcoming bottlenecks of genetic association studies. However, related statistical methods for testing SNP-SNP interactions are underdeveloped. Results: We propose the SNP Interaction Pattern Identifier (SIPI), which tests 45...

  3. Interaction with Soft Robotic Tentacles

    DEFF Research Database (Denmark)

    Jørgensen, Jonas

    2018-01-01

    Soft robotics technology has been proposed for a number of applications that involve human-robot interaction. In this tabletop demonstration it is possible to interact with two soft robotic platforms that have been used in human-robot interaction experiments (also accepted to HRI'18 as a Late...

  4. Species interactions and plant polyploidy.

    Science.gov (United States)

    Segraves, Kari A; Anneberg, Thomas J

    2016-07-01

    Polyploidy is a common mode of speciation that can have far-reaching consequences for plant ecology and evolution. Because polyploidy can induce an array of phenotypic changes, there can be cascading effects on interactions with other species. These interactions, in turn, can have reciprocal effects on polyploid plants, potentially impacting their establishment and persistence. Although there is a wealth of information on the genetic and phenotypic effects of polyploidy, the study of species interactions in polyploid plants remains a comparatively young field. Here we reviewed the available evidence for how polyploidy may impact many types of species interactions that range from mutualism to antagonism. Specifically, we focused on three main questions: (1) Does polyploidy directly cause the formation of novel interactions not experienced by diploids, or does it create an opportunity for natural selection to then form novel interactions? (2) Does polyploidy cause consistent, predictable changes in species interactions vs. the evolution of idiosyncratic differences? (3) Does polyploidy lead to greater evolvability in species interactions? From the scarce evidence available, we found that novel interactions are rare but that polyploidy can induce changes in pollinator, herbivore, and pathogen interactions. Although further tests are needed, it is likely that selection following whole-genome duplication is important in all types of species interaction and that there are circumstances in which polyploidy can enhance the evolvability of interactions with other species. © 2016 Botanical Society of America.

  5. Online Learners' Preferences for Interaction.

    Science.gov (United States)

    Northrup, Pamela T.

    2002-01-01

    Describes a study that investigated types of interaction that graduate students perceived to be important for elearning (electronic learning). Discusses content interaction, conversation and collaboration, interpersonal and metacognitive skills, and need for support; explains the Online Learning Interaction Inventory; and reports that flexibility…

  6. Galaxy interactions : The HI signature

    NARCIS (Netherlands)

    Sancisi, R; Barnes, JE; Sanders, DB

    1999-01-01

    HI observations are an excellent tool for investigating tidal interactions. Ongoing major and minor interactions which can lead to traumatic mergers or to accretion and the triggering of star formation, show distinct HI signatures. Interactions and mergers in the recent past can also be recognized

  7. Quadratic spatial soliton interactions

    Science.gov (United States)

    Jankovic, Ladislav

    Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO 3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the fundamental component only, showed a broad angular acceptance bandwidth which was important for the soliton collisions performed later. Furthermore, at high input intensities multi-soliton generation was observed for the first time. The influence on the multi-soliton patterns generated of the input intensity and beam symmetry was investigated. The combined experimental and theoretical efforts indicated that spatial and temporal noise on the input laser beam induced multi-soliton patterns. Another research direction pursued was intensity dependent soliton routing by using of a specially engineered quadratically nonlinear interface within a periodically poled KTP sample. This was the first time demonstration of the self-reflection phenomenon in a system with a quadratic nonlinearity. The feature investigated is believed to have a great potential for soliton routing and manipulation by engineered structures. A detailed investigation was conducted on two soliton interaction and collision processes. Birth of an additional soliton resulting from a two soliton collision was observed and characterized for the special case of a non-planar geometry. A small amount of spiraling, up to 30

  8. Human-Robot Interaction

    Science.gov (United States)

    Sandor, Aniko; Cross, E. Vincent, II; Chang, Mai Lee

    2015-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces affect the human's ability to perform tasks effectively and efficiently when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. For efficient and effective remote navigation of a rover, a human operator needs to be aware of the robot's environment. However, during teleoperation, operators may get information about the environment only through a robot's front-mounted camera causing a keyhole effect. The keyhole effect reduces situation awareness which may manifest in navigation issues such as higher number of collisions, missing critical aspects of the environment, or reduced speed. One way to compensate for the keyhole effect and the ambiguities operators experience when they teleoperate a robot is adding multiple cameras and including the robot chassis in the camera view. Augmented reality, such as overlays, can also enhance the way a person sees objects in the environment or in camera views by making them more visible. Scenes can be augmented with integrated telemetry, procedures, or map information. Furthermore, the addition of an exocentric (i.e., third-person) field of view from a camera placed in the robot's environment may provide operators with the additional information needed to gain spatial awareness of the robot. Two research studies investigated possible mitigation approaches to address the keyhole effect: 1) combining the inclusion of the robot chassis in the camera view with augmented reality overlays, and 2) modifying the camera

  9. Interacting neural networks

    Science.gov (United States)

    Metzler, R.; Kinzel, W.; Kanter, I.

    2000-08-01

    Several scenarios of interacting neural networks which are trained either in an identical or in a competitive way are solved analytically. In the case of identical training each perceptron receives the output of its neighbor. The symmetry of the stationary state as well as the sensitivity to the used training algorithm are investigated. Two competitive perceptrons trained on mutually exclusive learning aims and a perceptron which is trained on the opposite of its own output are examined analytically. An ensemble of competitive perceptrons is used as decision-making algorithms in a model of a closed market (El Farol Bar problem or the Minority Game. In this game, a set of agents who have to make a binary decision is considered.); each network is trained on the history of minority decisions. This ensemble of perceptrons relaxes to a stationary state whose performance can be better than random.

  10. Electroweak interactions at LEP

    International Nuclear Information System (INIS)

    Borgia, B.

    1991-01-01

    Electroweak interaction at LEP are a subject based on a wealth of data, given the success of the CERN e + e - storage ring. The author will report on the results from the four experiments, ALEPH, DELPHI, L3 and OPAL after the analysis of about 1/2 of the data collected in 1989 and 1990. The review will cover the electroweak aspects of the process e + e - → Z* → f bar f where the fermions can be either quarks or leptons. The analysis of experimental data is based on the determination of the cross section integrated on the solid angle and on the asymmetry of forward-backward leptons in the final state. In this game the knowledge of the center mass energy is fundamental as the determination of the luminosity by which the event rate is normalized to compute the absolute cross section. Therefore a specific attention is given to these subjects

  11. Plasma-surface interaction

    International Nuclear Information System (INIS)

    Kurnaev, V.A.

    1996-01-01

    The latest experimental results characterizing plasma interaction with walls in thermonuclear facilities are presented. The main attention is paid to the mode of plasma ejection from the tokamak divertor receiving elements to study the properties of the so-called gas divertor. A sharp reduction of load on the receiving plates is provided in the mode at the expense of over-radiation of a substantial share of power in a layer of peripheral removed plasma. However, the sharp reduction of load on the current-receiving plates is accompanied by an increase of the main plasma charge up to an unacceptably high level. An alternative variant of solving the problem of heat and impurity removal in the form of a concept of capillary lithium divertor is described. Besides, the latest results of experiments in simulator devices are presented. 46 refs., 15 figs

  12. Molecular Interactions at Membranes

    DEFF Research Database (Denmark)

    Jagalski, Vivien

    . Today, we know more than ever before about the properties of biological membranes. Advanced biophysical techniques and sophisticated membrane models allow us to answer specific questions about the structure of the components within membranes and their interactions. However, many detailed structural...... the surface-immobilization of LeuT by exchanging the detergent with natural phosphatidylcholine (PC) lipids. Various surface sensitive techniques, including neutron reflectometry (NR), are employed and finally enabled us to confirm the gross structure of LeuT in a lipid environment as predicted by molecular...... dynamic simulations. In a second study, the co-localization of three toxic plant-derived diterpene resin acids (RAs) within DPPC membranes was investigated. These compounds are reported to disrupt the membrane and increase its fluidity. The RAs used in this study vary in their toxicity while...

  13. The interactive design collaboratorium

    DEFF Research Database (Denmark)

    Bødker, Susanne; Petersen, Marianne Graves; Krogh, Peter Gall

    2001-01-01

    This paper reports on experimental process in which a prototype was developed of an interactive design collaboatorium, in cooperation with a group of usability designers. In a longterm research cooperation, this usability group has changed its work practice in order to work in the design...... collaboratorium. The design collaboratorium was developed to move usability design away from a lab towards an open physical and organizational space where designer, users and engineers meet and collaborate, or work alongside each other. The cooperation between researchers and the usability gruop has resulted...... in practical experimentation in projects and in design of an experimental design collaboratorium emploing electronic whiteboards, 3D design documentation, etc. This experimental prototype has been evaluated in cooperative workshops. We report on the results of this evaluation....

  14. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  15. Metal-ligand interactions

    Science.gov (United States)

    Ervin, Kent M.

    Experimental studies of the interactions of small transition-metal cluster anions with carbonyl ligands are reviewed and compared with neutral and cationic clusters. Under thermal conditions, the reaction rates of transition-metal clusters with carbon monoxide are measured as a function of cluster size. Saturation limits for carbon monoxide addition can be related to the geometric structures of the clusters. Both energy-resolved threshold collision-induced dissociation experiments and time-resolved photodissociation experiments are used to measure metal-carbonyl binding energies. For platinum and palladium trimer anions, the carbonyl binding energies are assigned to different geometric binding sites. Platinum and palladium cluster anions catalyse the oxidation of carbon monoxide to carbon dioxide in a full catalytic cycle at thermal energies.

  16. Sustainable Buildings in Interaction

    DEFF Research Database (Denmark)

    Elle, Morten

    2007-01-01

    The first attempts to build sustainable buildings in Denmark were typically located on the countryside. The basic idea was to create buildings that were independent of the technical infrastructure. District heating has, however, been the dominating solution to heating in buildings in Denmark......, and the focus on sustainable building have gradually turned from special houses on the countryside to normally looking houses in the urban fabric, integrated in the technical infrastructure. Some new built urban areas in Denmark will, however, not have to be supplied with district heating – these developments...... are going to consist of passive houses. The first sustainable buildings were built by their users, and the user – building interaction still play a decisive role for the performance of the present sustainable buildings. The users have to understand how the building functions. Urban design is essential...

  17. Metal-microorganism interactions

    International Nuclear Information System (INIS)

    Andres, Y.; Thouand, G.; Redercher, S.; Boualam, M.; Texier, A.Cl.; Hoeffer, R.

    1997-01-01

    The physico-chemical procedures of treating the metalliferous effluents are not always adapted to de polluting the slightly concentrated industrial wastes. An alternative idea was advanced, implying the ability of some microorganisms to fix in considerable amounts the metal ions present in aqueous solutions, possibly in a selective way. This approach has been investigated thoroughly during the last 30 years, particularly from a mechanistic point of view. The advantage of the microorganisms lies mainly in the large diversity of bacteria and in their chemical state dependent interaction with metals, as well as, in the possibilities of developing their selective and quantitative separation properties. A biomass from Mycobacterium smegmatis, an acidic alcoholic resistant bacteria, has been used to prepare a bio-sorption support allowing the preferential sorption of thorium as compared to uranium and lanthanum. These studies have been extended to biological polymers such as chitosan and to studies related to bioaccumulation mechanisms and/or to the microbial resistances towards metals

  18. Causal electromagnetic interaction equations

    International Nuclear Information System (INIS)

    Zinoviev, Yury M.

    2011-01-01

    For the electromagnetic interaction of two particles the relativistic causal quantum mechanics equations are proposed. These equations are solved for the case when the second particle moves freely. The initial wave functions are supposed to be smooth and rapidly decreasing at the infinity. This condition is important for the convergence of the integrals similar to the integrals of quantum electrodynamics. We also consider the singular initial wave functions in the particular case when the second particle mass is equal to zero. The discrete energy spectrum of the first particle wave function is defined by the initial wave function of the free-moving second particle. Choosing the initial wave functions of the free-moving second particle it is possible to obtain a practically arbitrary discrete energy spectrum.

  19. Solvent - solute interaction

    International Nuclear Information System (INIS)

    Urbanczyk, A.; Kalinowski, M.K.

    1983-01-01

    The electronic absorption spectrum of vanadyl acetylacetonate has been studied in 15 organic solvents. It has been found that wavenumbers and molar absorptivities of the long-wavelength bands (d-d transitions) can be well described by a complementary Lewis acid-base model including Gutmann's donor number [Gutmann V., Wychera E., Inorg. Nucl. Chem. Letters 2, 257 (1966)] and acceptor number [Mayer U., Gutmann V., Gerger W., Monatsh. Chem. 106, 1235 (1975)] of a solvent. This model describes also the solvent effect of the hyperfine splitting constant, Asub(iso)( 51 V), from e.s.r. spectra of VOacac 2 . These observations are discussed in terms of the donor-acceptor concept for solvent-solute interactions. (Author)

  20. Doing, using, interacting

    DEFF Research Database (Denmark)

    Nordin, Sara; Hjalager, Anne-Mette

    2017-01-01

    of innovation processes: science, technology, and innovation (STI) and doing, using, and interacting (DUI). DUI appears to capture the essence of innovation in tourism enterprises better than STI because it acknowledges the intrinsic nature of services and the typical size and working modes of touristic actors......Innovation is a critical factor for long-term economic development, including in tourism. This chapter examines the processes that lead to new products and services in a tourism context. It does so based on two commonly referred to modes of innovation (Jensen et al., 2007); that is, two types....... The case study of Icehotel illustrates how working in partnerships and in close cooperation with customers enhances the advantages of the DUI model. The handling of externally induced events and difficulties and the critical partnerships are better understood through the DUI than through the STI lens...

  1. Dark patterns in proxemic interactions

    DEFF Research Database (Denmark)

    Greenberg, Saul; Boring, Sebastian; Vermeulen, Jo

    2014-01-01

    to better facilitate seamless and natural interactions. To do so, both people and devices are tracked to determine their spatial relationships. While interest in proxemic interactions has increased over the last few years, it also has a dark side: knowledge of proxemics may (and likely will) be easily...... exploited to the detriment of the user. In this paper, we offer a critical perspective on proxemic interactions in the form of dark patterns: ways proxemic interactions can be misused. We discuss a series of these patterns and describe how they apply to these types of interactions. In addition, we identify...

  2. Probing kink interactions with fermions

    International Nuclear Information System (INIS)

    Carlitz, R.; Chakrabarti, R.

    1985-01-01

    A dilute gas of kinks exhibits strong but short-ranged intrinsic interactions. When these intrinsic interactions are supplemented by other ''extrinsic'' interactions, a phase transition can occur in which kinks and antikinks bind to form a gas of bounces. The extrinsic interactions arise from the coupling of kinks to an additional degree of freedom, which we take to be a fermion field. The class of quantum-mechanical models which we study includes examples of supersymmetry. The way in which kinks and antikinks bind depends in detail on aspects of the intrinsic interactions. This structure is probably shared by field-theoretic models

  3. Interaction Themes in Music Therapy

    DEFF Research Database (Denmark)

    Holck, Ulla

    2006-01-01

    Based on a doctoral study, the author presents a type of music therapy interaction called ‘Interaction Themes.’ These are developed from session to session and often appear in music therapy interventions with children with severe functional limitations, especially children with autism. Although...... whose expressions are often difficult to understand. The presented article describes the characteristics and functions of Interaction Themes, compares the phenomenon with music therapy case literature and delimits it in regard to other types of music therapy interaction with this client group....... the Interaction Themes are characterised by a relatively simple and self-generated content, they have an essential function because they contain the child’s and music therapist’s joint interaction history. They make up the context within which it is possible to create meaningful interaction with a client group...

  4. The 'Interactive' of Interactive Storytelling: Customizing the Gaming Experience

    OpenAIRE

    Bostan , Barbaros; Marsh , Tim

    2010-01-01

    International audience; In this article, we define interactive storytelling as a gaming experience where the form and content of the game is customized in real time and tailored to the preferences and needs of the player to maximixe enjoyment. The primary focus of interactive storytelling should not be on the attributes of the technology or characteristics of the medium, such as the AI techniques, planning formalisms, story representations, etc. but on different interaction levels provided by...

  5. Interacting With Robots to Investigate the Bases of Social Interaction.

    Science.gov (United States)

    Sciutti, Alessandra; Sandini, Giulio

    2017-12-01

    Humans show a great natural ability at interacting with each other. Such efficiency in joint actions depends on a synergy between planned collaboration and emergent coordination, a subconscious mechanism based on a tight link between action execution and perception. This link supports phenomena as mutual adaptation, synchronization, and anticipation, which cut drastically the delays in the interaction and the need of complex verbal instructions and result in the establishment of joint intentions, the backbone of social interaction. From a neurophysiological perspective, this is possible, because the same neural system supporting action execution is responsible of the understanding and the anticipation of the observed action of others. Defining which human motion features allow for such emergent coordination with another agent would be crucial to establish more natural and efficient interaction paradigms with artificial devices, ranging from assistive and rehabilitative technology to companion robots. However, investigating the behavioral and neural mechanisms supporting natural interaction poses substantial problems. In particular, the unconscious processes at the basis of emergent coordination (e.g., unintentional movements or gazing) are very difficult-if not impossible-to restrain or control in a quantitative way for a human agent. Moreover, during an interaction, participants influence each other continuously in a complex way, resulting in behaviors that go beyond experimental control. In this paper, we propose robotics technology as a potential solution to this methodological problem. Robots indeed can establish an interaction with a human partner, contingently reacting to his actions without losing the controllability of the experiment or the naturalness of the interactive scenario. A robot could represent an "interactive probe" to assess the sensory and motor mechanisms underlying human-human interaction. We discuss this proposal with examples from our

  6. Dike/Drift Interactions

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Gaffney

    2003-10-08

    This report documents the model of events associated with a potential intrusion of magma from a volcanic dike into a drift or drifts in the Yucca Mountain Nuclear Waste Repository. The following topics are included in this report: (1) A discussion of dike propagation, which provides the basis for describing the path that a representative dike, or swarm of dikes, would follow during an event. (2) A discussion of magma flow, which evaluates the interaction at the junction of the propagating dike with the drift and the movement of magmatic products into and down drifts and, potentially, through a drift to the surface by way of access drift or a secondary dike opened up along the drift. (3) A discussion of gas flow and conductive cooling of a magma-filled drift, describing how an adjacent drift that has not been intersected by a dike could be affected by post-intrusion phenomena. Note that a gas flow analysis is also addressed in ''Igneous Intrusion Impacts on Waste Form and Waste Packages'' (BSC 2003 [DIRS 161810]), and those results are consistent with the results presented in this report.

  7. SEEPAGE/BACKFILL INTERACTIONS

    International Nuclear Information System (INIS)

    Mariner, P.

    2000-01-01

    As directed by written development plan (CRWMS M andO 1999a), a sub-model of seepage/backfill interactions is developed and presented in this document to support the Engineered Barrier System (EBS) Physical and Chemical Environment Model. The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift. In this analysis, a conceptual model is developed to provide PAO a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The development plan calls for a sub-model that evaluates the effect on water chemistry of chemical reactions between water that enters the drift and backfill materials in the drift. The development plan specifically requests an evaluation of the following important chemical reaction processes: dissolution-precipitation, aqueous complexation, and oxidation-reduction. The development plan also requests the evaluation of the effects of varying seepage and drainage fluxes, varying temperature, and varying evaporation and condensation fluxes. Many of these effects are evaluated in a separate Analysis/Model Report (AMR), ''Precipitates Salts Analysis AMR'' (CRWMS M andO 2000), so the results of that AMR are referenced throughout this AMR

  8. Dike/Drift Interactions

    International Nuclear Information System (INIS)

    E.S. Gaffney

    2003-01-01

    This report documents the model of events associated with a potential intrusion of magma from a volcanic dike into a drift or drifts in the Yucca Mountain Nuclear Waste Repository. The following topics are included in this report: (1) A discussion of dike propagation, which provides the basis for describing the path that a representative dike, or swarm of dikes, would follow during an event. (2) A discussion of magma flow, which evaluates the interaction at the junction of the propagating dike with the drift and the movement of magmatic products into and down drifts and, potentially, through a drift to the surface by way of access drift or a secondary dike opened up along the drift. (3) A discussion of gas flow and conductive cooling of a magma-filled drift, describing how an adjacent drift that has not been intersected by a dike could be affected by post-intrusion phenomena. Note that a gas flow analysis is also addressed in ''Igneous Intrusion Impacts on Waste Form and Waste Packages'' (BSC 2003 [DIRS 161810]), and those results are consistent with the results presented in this report

  9. SEEPAGE/BACKFILL INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    P. Mariner

    2000-04-14

    As directed by written development plan (CRWMS M&O 1999a), a sub-model of seepage/backfill interactions is developed and presented in this document to support the Engineered Barrier System (EBS) Physical and Chemical Environment Model. The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift. In this analysis, a conceptual model is developed to provide PAO a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The development plan calls for a sub-model that evaluates the effect on water chemistry of chemical reactions between water that enters the drift and backfill materials in the drift. The development plan specifically requests an evaluation of the following important chemical reaction processes: dissolution-precipitation, aqueous complexation, and oxidation-reduction. The development plan also requests the evaluation of the effects of varying seepage and drainage fluxes, varying temperature, and varying evaporation and condensation fluxes. Many of these effects are evaluated in a separate Analysis/Model Report (AMR), ''Precipitates Salts Analysis AMR'' (CRWMS M&O 2000), so the results of that AMR are referenced throughout this AMR.

  10. Interaction of the radiation with matter

    International Nuclear Information System (INIS)

    2013-01-01

    This third chapter presents the ionization, excitation, activation and radiation breaking; radiation directly and indirectly ionizing; interaction of the electromagnetic radiation with matter; interaction of neutrons with matter; interaction of radiation directly ionizing with matter; interaction of electrons with matter, interaction of alpha particle with matter; interaction of fission fragments with matter; travel time and integrated processes of interaction: energy dissipation

  11. RJSplot: Interactive Graphs with R.

    Science.gov (United States)

    Barrios, David; Prieto, Carlos

    2018-03-01

    Data visualization techniques provide new methods for the generation of interactive graphs. These graphs allow a better exploration and interpretation of data but their creation requires advanced knowledge of graphical libraries. Recent packages have enabled the integration of interactive graphs in R. However, R provides limited graphical packages that allow the generation of interactive graphs for computational biology applications. The present project has joined the analytical power of R with the interactive graphical features of JavaScript in a new R package (RJSplot). It enables the easy generation of interactive graphs in R, provides new visualization capabilities, and contributes to the advance of computational biology analytical methods. At present, 16 interactive graphics are available in RJSplot, such as the genome viewer, Manhattan plots, 3D plots, heatmaps, dendrograms, networks, and so on. The RJSplot package is freely available online at http://rjsplot.net. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Interactive Dimensioning of Parametric Models

    KAUST Repository

    Kelly, T.

    2015-06-22

    We propose a solution for the dimensioning of parametric and procedural models. Dimensioning has long been a staple of technical drawings, and we present the first solution for interactive dimensioning: A dimension line positioning system that adapts to the view direction, given behavioral properties. After proposing a set of design principles for interactive dimensioning, we describe our solution consisting of the following major components. First, we describe how an author can specify the desired interactive behavior of a dimension line. Second, we propose a novel algorithm to place dimension lines at interactive speeds. Third, we introduce multiple extensions, including chained dimension lines, controls for different parameter types (e.g. discrete choices, angles), and the use of dimension lines for interactive editing. Our results show the use of dimension lines in an interactive parametric modeling environment for architectural, botanical, and mechanical models.

  13. Gaussian interaction profile kernels for predicting drug-target interaction.

    Science.gov (United States)

    van Laarhoven, Twan; Nabuurs, Sander B; Marchiori, Elena

    2011-11-01

    The in silico prediction of potential interactions between drugs and target proteins is of core importance for the identification of new drugs or novel targets for existing drugs. However, only a tiny portion of all drug-target pairs in current datasets are experimentally validated interactions. This motivates the need for developing computational methods that predict true interaction pairs with high accuracy. We show that a simple machine learning method that uses the drug-target network as the only source of information is capable of predicting true interaction pairs with high accuracy. Specifically, we introduce interaction profiles of drugs (and of targets) in a network, which are binary vectors specifying the presence or absence of interaction with every target (drug) in that network. We define a kernel on these profiles, called the Gaussian Interaction Profile (GIP) kernel, and use a simple classifier, (kernel) Regularized Least Squares (RLS), for prediction drug-target interactions. We test comparatively the effectiveness of RLS with the GIP kernel on four drug-target interaction networks used in previous studies. The proposed algorithm achieves area under the precision-recall curve (AUPR) up to 92.7, significantly improving over results of state-of-the-art methods. Moreover, we show that using also kernels based on chemical and genomic information further increases accuracy, with a neat improvement on small datasets. These results substantiate the relevance of the network topology (in the form of interaction profiles) as source of information for predicting drug-target interactions. Software and Supplementary Material are available at http://cs.ru.nl/~tvanlaarhoven/drugtarget2011/. tvanlaarhoven@cs.ru.nl; elenam@cs.ru.nl. Supplementary data are available at Bioinformatics online.

  14. Intergenerational Analysis of Social Interaction

    OpenAIRE

    Brown, Sarah; McHardy, Jolian; Taylor, Karl

    2011-01-01

    We explore the relationship between the social interaction of parents and their offspring from a theoretical and an empirical perspective. Our theoretical framework establishes possible explanations for the intergenerational transfer of social interaction whereby the social interaction of the parent may influence that of their offspring and vice versa. The empirical evidence, based on four data sets covering Great Britain and the U.S., is supportive of our theoretical priors. We find robust e...

  15. Conversation Analysis and Classroom Interaction

    Institute of Scientific and Technical Information of China (English)

    DING A-ning; LI Fan; CUI Jing

    2015-01-01

    Conversation Analysis shows the evidence of the social nature of people’s action including talk-in-interaction from a micro-level perspective. The method for basing its analysis on the authentic data rather than the retrospective interviews for gain⁃ing the participants’perception makes it unique in discovering the emic perspective of the social interaction. CA, often called as a“micro”methodology, provides theoretical insights and useful analytical tool for exploring the interaction in classrooms.

  16. Emotional responses to interactive fictions

    OpenAIRE

    Hagger, Andrzej

    2012-01-01

    We commonly feel a variety of emotional responses to works of fiction. In this thesis I propose to examine what we understand by the terms fictional and narrative, and to describe what sorts of narrator might be required within a narrative work. Of particular interest are interactive works of art, both narrative and non-narrative, and I provide a definition of what features a work should possess if it should properly be considered interactive. I discuss the notions of interactive narrative...

  17. INCA- INTERACTIVE CONTROLS ANALYSIS

    Science.gov (United States)

    Bauer, F. H.

    1994-01-01

    The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z

  18. Seepage/Cement Interactions

    International Nuclear Information System (INIS)

    Carpenter, D.

    2000-01-01

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO 2 . (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as

  19. On topological RNA interaction structures.

    Science.gov (United States)

    Qin, Jing; Reidys, Christian M

    2013-07-01

    Recently a folding algorithm of topological RNA pseudoknot structures was presented in Reidys et al. (2011). This algorithm folds single-stranded γ-structures, that is, RNA structures composed by distinct motifs of bounded topological genus. In this article, we set the theoretical foundations for the folding of the two backbone analogues of γ structures: the RNA γ-interaction structures. These are RNA-RNA interaction structures that are constructed by a finite number of building blocks over two backbones having genus at most γ. Combinatorial properties of γ-interaction structures are of practical interest since they have direct implications for the folding of topological interaction structures. We compute the generating function of γ-interaction structures and show that it is algebraic, which implies that the numbers of interaction structures can be computed recursively. We obtain simple asymptotic formulas for 0- and 1-interaction structures. The simplest class of interaction structures are the 0-interaction structures, which represent the two backbone analogues of secondary structures.

  20. Quasiparticle interaction in nuclear matter

    International Nuclear Information System (INIS)

    Poggioli, R.S.; Jackson, A.D.

    1975-07-01

    A microscopic calculation of the quasiparticle interaction in nuclear matter is detailed. In order to take especial care of the contributions from the low momentum states, a model space is introduced. Excluded from the model space, the high momentum states are absorbed into the model interaction. Brueckner theory suggests the choice of a truncated G-matrix as a good approximation for this model interaction. A simple perturbative approach is attempted within the model space. The calculated quasiparticle interaction is consistent with experimental results. (11 tables, 14 figures)

  1. Theoretical studies of molecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lester, W.A. Jr. [Univ. of California, Berkeley (United States)

    1993-12-01

    This research program is directed at extending fundamental knowledge of atoms and molecules including their electronic structure, mutual interaction, collision dynamics, and interaction with radiation. The approach combines the use of ab initio methods--Hartree-Fock (HF) multiconfiguration HF, configuration interaction, and the recently developed quantum Monte Carlo (MC)--to describe electronic structure, intermolecular interactions, and other properties, with various methods of characterizing inelastic and reaction collision processes, and photodissociation dynamics. Present activity is focused on the development and application of the QMC method, surface catalyzed reactions, and reorientation cross sections.

  2. Evaluation of drug interaction microcomputer software: Dambro's Drug Interactions.

    Science.gov (United States)

    Poirier, T I; Giudici, R A

    1990-01-01

    Dambro's Drug Interactions was evaluated using general and specific criteria. The installation process, ease of learning and use were rated excellent. The user documentation and quality of the technical support were good. The scope of coverage, clinical documentation, frequency of updates, and overall clinical performance were fair. The primary advantages of the program are the quick searching and detection of drug interactions, and the attempt to provide useful interaction data, i.e., significance and reference. The disadvantages are the lack of current drug interaction information, outdated references, lack of evaluative drug interaction information, and the inability to save or print patient profiles. The program is not a good value for the pharmacist but has limited use as a quick screening tool.

  3. The n→π* Interaction.

    Science.gov (United States)

    Newberry, Robert W; Raines, Ronald T

    2017-08-15

    The carbonyl group holds a prominent position in chemistry and biology not only because it allows diverse transformations but also because it supports key intermolecular interactions, including hydrogen bonding. More recently, carbonyl groups have been found to interact with a variety of nucleophiles, including other carbonyl groups, in what we have termed an n→π* interaction. In an n→π* interaction, a nucleophile donates lone-pair (n) electron density into the empty π* orbital of a nearby carbonyl group. Mixing of these orbitals releases energy, resulting in an attractive interaction. Hints of such interactions were evident in small-molecule crystal structures as early as the 1970s, but not until 2001 was the role of such interactions articulated clearly. These non-covalent interactions were first discovered during investigations into the thermostability of the proline-rich protein collagen, which achieves a robust structure despite a relatively low potential for hydrogen bonding. It was found that by modulating the distance between two carbonyl groups in the peptide backbone, one could alter the conformational preferences of a peptide bond to proline. Specifically, only the trans conformation of a peptide bond to proline allows for an attractive interaction with an adjacent carbonyl group, so when one increases the proximity of the two carbonyl groups, one enhances their interaction and promotes the trans conformation of the peptide bond, which increases the thermostability of collagen. More recently, attention has been paid to the nature of these interactions. Some have argued that rather than resulting from electron donation, carbonyl interactions are a particular example of dipolar interactions that are well-approximated by classical mechanics. However, experimental evidence has demonstrated otherwise. Numerous examples now exist where an increase in the dipole moment of a carbonyl group decreases the strength of its interactions with other carbonyl

  4. The cation-π interaction.

    Science.gov (United States)

    Dougherty, Dennis A

    2013-04-16

    The chemistry community now recognizes the cation-π interaction as a major force for molecular recognition, joining the hydrophobic effect, the hydrogen bond, and the ion pair in determining macromolecular structure and drug-receptor interactions. This Account provides the author's perspective on the intellectual origins and fundamental nature of the cation-π interaction. Early studies on cyclophanes established that water-soluble, cationic molecules would forego aqueous solvation to enter a hydrophobic cavity if that cavity was lined with π systems. Important gas phase studies established the fundamental nature of the cation-π interaction. The strength of the cation-π interaction (Li(+) binds to benzene with 38 kcal/mol of binding energy; NH4(+) with 19 kcal/mol) distinguishes it from the weaker polar-π interactions observed in the benzene dimer or water-benzene complexes. In addition to the substantial intrinsic strength of the cation-π interaction in gas phase studies, the cation-π interaction remains energetically significant in aqueous media and under biological conditions. Many studies have shown that cation-π interactions can enhance binding energies by 2-5 kcal/mol, making them competitive with hydrogen bonds and ion pairs in drug-receptor and protein-protein interactions. As with other noncovalent interactions involving aromatic systems, the cation-π interaction includes a substantial electrostatic component. The six (four) C(δ-)-H(δ+) bond dipoles of a molecule like benzene (ethylene) combine to produce a region of negative electrostatic potential on the face of the π system. Simple electrostatics facilitate a natural attraction of cations to the surface. The trend for (gas phase) binding energies is Li(+) > Na(+) > K(+) > Rb(+): as the ion gets larger the charge is dispersed over a larger sphere and binding interactions weaken, a classical electrostatic effect. On other hand, polarizability does not define these interactions. Cyclohexane is

  5. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  6. Macrolide drug interactions: an update.

    Science.gov (United States)

    Pai, M P; Graci, D M; Amsden, G W

    2000-04-01

    To describe the current drug interaction profiles for the commonly used macrolides in the US and Europe, and to comment on the clinical impact of these interactions. A MEDLINE search (1975-1998) was performed to identify all pertinent studies, review articles, and case reports. When appropriate information was not available in the literature, data were obtained from the product manufacturers. All available data were reviewed to provide an unbiased account of possible drug interactions. Data for some of the interactions were not available from the literature, but were available from abstracts or company-supplied materials. Although the data were not always explicit, the best attempt was made to deliver pertinent information that clinical practitioners would need to formulate practice opinions. When more in-depth information was supplied in the form of a review or study report, a thorough explanation of pertinent methodology was supplied. Several clinically significant drug interactions have been identified since the approval of erythromycin. These interactions usually were related to the inhibition of the cytochrome P450 enzyme systems, which are responsible for the metabolism of many drugs. The decreased metabolism by the macrolides has in some instances resulted in potentially severe adverse events. The development and marketing of newer macrolides are hoped to improve the drug interaction profile associated with this class. However, this has produced variable success. Some of the newer macrolides demonstrated an interaction profile similar to that of erythromycin; others have improved profiles. The most success in avoiding drug interactions related to the inhibition of cytochrome P450 has been through the development of the azalide subclass, of which azithromycin is the first and only to be marketed. Azithromycin has not been demonstrated to inhibit the cytochrome P450 system in studies using a human liver microsome model, and to date has produced none of the

  7. Educational interactive multimedia software: The impact of interactivity on learning

    Science.gov (United States)

    Reamon, Derek Trent

    This dissertation discusses the design, development, deployment and testing of two versions of educational interactive multimedia software. Both versions of the software are focused on teaching mechanical engineering undergraduates about the fundamentals of direct-current (DC) motor physics and selection. The two versions of Motor Workshop software cover the same basic materials on motors, but differ in the level of interactivity between the students and the software. Here, the level of interactivity refers to the particular role of the computer in the interaction between the user and the software. In one version, the students navigate through information that is organized by topic, reading text, and viewing embedded video clips; this is referred to as "low-level interactivity" software because the computer simply presents the content. In the other version, the students are given a task to accomplish---they must design a small motor-driven 'virtual' vehicle that competes against computer-generated opponents. The interaction is guided by the software which offers advice from 'experts' and provides contextual information; we refer to this as "high-level interactivity" software because the computer is actively participating in the interaction. The software was used in two sets of experiments, where students using the low-level interactivity software served as the 'control group,' and students using the highly interactive software were the 'treatment group.' Data, including pre- and post-performance tests, questionnaire responses, learning style characterizations, activity tracking logs and videotapes were collected for analysis. Statistical and observational research methods were applied to the various data to test the hypothesis that the level of interactivity effects the learning situation, with higher levels of interactivity being more effective for learning. The results show that both the low-level and high-level interactive versions of the software were effective

  8. Dynamic behaviour of nominal and PACMAN bunches for different LHC crossing schemes

    CERN Document Server

    Herr, Werner

    2005-01-01

    To avoid unwanted beam-beam interactions, the two LHC beams cross at an angle in all experimental interaction regions. The choice of the crossing plane in the different areas has fundamental consequences on the effects of the long range beam-beam interaction. An alternating crossing scheme, i.e. horizontal and vertical crossing planes in the two high luminosity experiments, is presently foreseen to partly compensate and minimize first order effects on PACMAN bunches. Recent studies with a simplified model of the machine suggested that an alternating crossing scheme may be less favourable due to a reduced dynamic aperture. In this report I investigate this assertion with a detailed tracking study. The head on and long range beam-beam effects are taken into account as well as machine imperfections. The effects on the dynamic aperture of nominal and PACMAN bunches are evaluated.

  9. Our interests in protein-protein interactions

    Indian Academy of Sciences (India)

    protein interactions. Evolution of P-P partnerships. Evolution of P-P structures. Evolutionary dynamics of P-P interactions. Dynamics of P-P interaction network. Host-pathogen interactions. CryoEM mapping of gigantic protein assemblies.

  10. Parallel inter channel interaction mechanisms

    International Nuclear Information System (INIS)

    Jovic, V.; Afgan, N.; Jovic, L.

    1995-01-01

    Parallel channels interactions are examined. For experimental researches of nonstationary regimes flow in three parallel vertical channels results of phenomenon analysis and mechanisms of parallel channel interaction for adiabatic condition of one-phase fluid and two-phase mixture flow are shown. (author)

  11. Depletion interactions in lyotropic nematics

    NARCIS (Netherlands)

    Schoot, van der P.P.A.M.

    2000-01-01

    A theoretical study of depletion interactions between pairs of small, globular colloids dispersed in a lyotropic nematic of hard, rodlike particles is presented. We find that both the strength and range of the interaction crucially depends on the configuration of the spheres relative to the nematic

  12. Moderating influences on interactivity effects

    NARCIS (Netherlands)

    Voorveld, H.; van Noort, G.

    2012-01-01

    Research on website interactivity is widespread and there are two important reasons for this popularity. The first is that interactivity is assumed to be the key characteristic that distinguishes communication in traditional media from communication in new media such as websites (Chung and Zhao,

  13. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements...

  14. Direction: unified theory of interactions

    International Nuclear Information System (INIS)

    Valko, P.

    1987-01-01

    Briefly characterized are the individual theories, namely, the general relativity theory, the Kaluza-Klein theory, the Weyl theory, the unified theory of electromagnetic and weak interactions, the supergravity theory, and the superstring theory. The history is recalled of efforts aimed at creating a unified theory of interactions, and future prospects are outlined. (M.D.). 2 figs

  15. Experimental Aspects of Nuclear Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Slaus, I. [Institute ' ' Rudjer Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1970-07-15

    1. Introduction; 2. Basic features of nuclear interaction; 3. How accurate is our present knowledge of phase parameters? 4. Experimental problems in N-N scattering studies; 5. N-N potential models; 6. Some open problems in nuclear interaction studies. (author)

  16. Assessing Preference for Social Interactions

    Science.gov (United States)

    Clay, Casey J.; Samaha, Andrew L.; Bloom, Sarah E.; Bogoev, Bistra K.; Boyle, Megan A.

    2013-01-01

    We examined a procedure to assess preference for social interactions in individuals with intellectual and developmental disabilities. Preferences were identified in five individuals using a paired-choice procedure in which participants approached therapists who provided different forms of social interactions. A subsequent tracking test showed that…

  17. Reggeon interactions in perturbative QCD

    International Nuclear Information System (INIS)

    Kirschner, R.

    1994-08-01

    We study the pairwise interaction of reggeized gluons and quarks in the Regge limit of perturbative QCD. The interactions are represented as integral kernels in the transverse momentum space and as operators in the impact parameter space. We observe conformal symmetry and holomorphic factorization in all cases. (orig.)

  18. Mobile Collocated Interactions With Wearables

    DEFF Research Database (Denmark)

    Lucero, Andrés; Wilde, Danielle; Robinson, Simon

    2015-01-01

    Research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices, thus going from personal/individual toward shared/multiuser experiences and interactions. However, computers are getting smaller, more...

  19. Child-Computer Interaction SIG

    DEFF Research Database (Denmark)

    Hourcade, Juan Pablo; Revelle, Glenda; Zeising, Anja

    2016-01-01

    This SIG will provide child-computer interaction researchers and practitioners an opportunity to discuss four topics that represent new challenges and opportunities for the community. The four areas are: interactive technologies for children under the age of five, technology for inclusion, privacy...... and information security in the age of the quantified self, and the maker movement....

  20. Interaction Sheaves on Continuous Domains

    DEFF Research Database (Denmark)

    Abdou, J.; Keiding, Hans

    We introduce a description of the power structure which is inherent in a strategic game form using the concept of an interaction sheaf. The latter assigns to each open set of outcomes a set of interaction arrays, specifying the changes that coalitions can make if outcome belongs to this open set....

  1. Interaction sheaves on continuous domains

    DEFF Research Database (Denmark)

    Abdou, Joseph; Keiding, Hans

    2009-01-01

    We introduce a description of the power structure which is inherent in a strategic game form using the concept of an interaction sheaf. The latter assigns to each open set of outcomes a set of interaction arrays, specifying the changes that coalitions can make if outcome belongs to this open set....

  2. Hypervideos and interactive multimedia presentations

    NARCIS (Netherlands)

    B. Meixner (Britta)

    2017-01-01

    textabstractHypervideos and interactive multimedia presentations allow the creation of fully interactive and enriched video. It is possible to organize video scenes in a nonlinear way. Additional information can be added to the video ranging from short descriptions to images and more videos.

  3. Transformations: Mobile Interaction & Language Learning

    Science.gov (United States)

    Carroll, Fiona; Kop, Rita; Thomas, Nathan; Dunning, Rebecca

    2015-01-01

    Mobile devices and the interactions that these technologies afford have the potential to change the face and nature of education in our schools. Indeed, mobile technological advances are seen to offer better access to educational material and new interactive ways to learn. However, the question arises, as to whether these new technologies are…

  4. Narrative Cognition in Interactive Systems

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio; Baceviciute, Sarune; Arief, Mohammed

    2014-01-01

    In this article we explore some of the methodological problems related to characterizing cognitive aspects of involvement with interactive narratives using well known EEG/ERP techniques. To exemplify this, we construct an experimental EEG-ERP set-up with an interactive narrative that considers th...

  5. Documentation of Appliances & Interaction Devices

    DEFF Research Database (Denmark)

    2004-01-01

    The interaction devices and appliances explored in the WorkSPACE project, address spatial computing in the context of work. We have developed and explored a range of appliances and interaction devices. The scope has been to develop tools for support of collaboration by mixing digital and physical...

  6. Quark confinement and hadronic interactions

    International Nuclear Information System (INIS)

    Lenz, F.

    1985-01-01

    With the possibility for 'exact' calculations within the framework of a fundamental theory, QCD, the role of models in strong interaction physics is changing radically. The relevance of detailed numerical model studies is diminishing with the development of those exact, numerical approaches to QCD. On the other hand, the insight gained from such purely numerical studies is necessarily limited and must be complemented by the more qualitative but also more intuitive insight gained from model studies. In particular, the subject of hadron-hadron interactions requires model studies to relate the wide variety of strong interaction physics to the fundamental properties of strong interaction physics. The author reports on such model studies of the hadron-hadron interaction

  7. Emotional intelligence and social interaction.

    Science.gov (United States)

    Lopes, Paulo N; Brackett, Marc A; Nezlek, John B; Schütz, Astrid; Sellin, Ina; Salovey, Peter

    2004-08-01

    Two studies found positive relationships between the ability to manage emotions and the quality of social interactions, supporting the predictive and incremental validity of an ability measure of emotional intelligence, the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). In a sample of 118 American college students (Study 1), higher scores on the managing emotions subscale of the MSCEIT were positively related to the quality of interactions with friends, evaluated separately by participants and two friends. In a diary study of social interaction with 103 German college students (Study 2), managing emotions scores were positively related to the perceived quality of interactions with opposite sex individuals. Scores on this subscale were also positively related to perceived success in impression management in social interactions with individuals of the opposite sex. In both studies, the main findings remained statistically significant after controlling for Big Five personality traits.

  8. Drug Interactions in Childhood Cancer

    Science.gov (United States)

    Haidar, Cyrine; Jeha, Sima

    2016-01-01

    Children with cancer are increasingly benefiting from novel therapeutic strategies and advances in supportive care, as reflected in improvements in both their survival and quality of life. However, the continuous emergence of new oncology drugs and supportive care agents has also increased the possibility of deleterious drug interactions and healthcare providers need to practice extreme caution when combining medications. In this review, we discuss the most common interactions of chemotherapeutic agents with supportive care drugs such as anticonvulsants, antiemetics, uric acid–lowering agents, acid suppressants, antimicrobials, and pain management medications in pediatric oncology patients. As chemotherapy agents interact not only with medications but also with foods and herbal supplements that patients receive during the course of their treatment, we also briefly review such interactions and provide recommendations to avoid unwanted and potentially fatal interactions in children with cancer. PMID:20869315

  9. Novicidin interactions with phospholipid membranes

    DEFF Research Database (Denmark)

    Balakrishnan, Vijay Shankar

    Antimicrobial peptides target bacterial cell membranes and are considered as potential antibiotics. Their interactions with cell membranes are studied using different approaches. This thesis comprises of the biophysical investigations on the antimicrobial peptide Novicidin, interacting with lipos......Antimicrobial peptides target bacterial cell membranes and are considered as potential antibiotics. Their interactions with cell membranes are studied using different approaches. This thesis comprises of the biophysical investigations on the antimicrobial peptide Novicidin, interacting...... with liposomes. The lipid-induced changes in the peptide due to membrane binding, and the peptide-induced changes in the membrane properties were investigated using various spectroscopic and calorimetric methods, and the structural and thermodynamic aspects of peptide-lipid interactions are discussed. This helps...

  10. Interaction themes in music therapy

    DEFF Research Database (Denmark)

    Holck, Ulla

    2004-01-01

    Based on a doctoral study, the author presents a type of music therapyinteraction called ?Interaction Themes.? These are developed fromsession to session and often appear in music therapy interventions withchildren with severe functional limitations, especially children withautism. Although...... whoseexpressions are often difficult to understand. The article describes thecharacteristics and functions of Interaction Themes, compares thephenomenon with music therapy case literature and delimits it in regardto other types of music therapy interaction with this client group. Theresults are described through...... the Interaction Themes are characterised by arelatively simple and self-generated content, they have an essentialfunction because they contain the child?s and music therapist?s jointinteraction history. They make up the context within which it ispossible to create meaningful interaction with a client group...

  11. Expanding the Interaction Equivalency Theorem

    Directory of Open Access Journals (Sweden)

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

    Full Text Available Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner is present at a high level. This study sought to apply this theorem to the corporate sector, and to expand it to include other indicators of course effectiveness: satisfaction, knowledge transfer, business results and return on expectations. A large Mexican organisation participated in this research, with 146 learners, 30 teachers and 3 academic assistants. Three versions of an online course were designed, each emphasising a different type of interaction. Data were collected through surveys, exams, observations, activity logs, think aloud protocols and sales records. All course versions yielded high levels of effectiveness, in terms of satisfaction, learning and return on expectations. Yet, course design did not dictate the types of interactions in which students engaged within the courses. Findings suggest that the interaction equivalency theorem can be reformulated as follows: In corporate settings, an online course can be effective in terms of satisfaction, learning, knowledge transfer, business results and return on expectations, as long as (a at least one of three types of interaction (learner-content, learner-teacher or learner-learner features prominently in the design of the course, and (b course delivery is consistent with the chosen type of interaction. Focusing on only one type of interaction carries a high risk of confusion, disengagement or missed learning opportunities, which can be managed by incorporating other forms of interactions.

  12. Final State Interactions Effects in Neutrino-Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Golan, Tomasz [Univ. of Wroctaw (Poland); Juszczak, Cezary [Univ. of Wroctaw (Poland); Sobczyk, Jan T. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2012-07-01

    Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $\\pi^0$ production data in $\\sim 1$ GeV neutrino flux experiments is demonstrated.

  13. Calculation of Rydberg interaction potentials

    International Nuclear Information System (INIS)

    Weber, Sebastian; Büchler, Hans Peter; Tresp, Christoph; Urvoy, Alban; Hofferberth, Sebastian; Menke, Henri; Firstenberg, Ofer

    2017-01-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence can be fine-tuned with great flexibility by choosing appropriate Rydberg states and applying external electric and magnetic fields. More and more experiments are probing this interaction at short atomic distances or with such high precision that perturbative calculations as well as restrictions to the leading dipole–dipole interaction term are no longer sufficient. In this tutorial, we review all relevant aspects of the full calculation of Rydberg interaction potentials. We discuss the derivation of the interaction Hamiltonian from the electrostatic multipole expansion, numerical and analytical methods for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up to higher multipole orders on a desktop computer. Finally, we present example calculations showing the relevance of the full interaction calculation to current experiments. Our software for calculating Rydberg potentials including all features discussed in this tutorial is available as open source. (tutorial)

  14. Evolutionary dynamics under interactive diversity

    Science.gov (United States)

    Su, Qi; Li, Aming; Wang, Long

    2017-10-01

    As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

  15. Aquaporin Protein-Protein Interactions

    Directory of Open Access Journals (Sweden)

    Jennifer Virginia Roche

    2017-10-01

    Full Text Available Aquaporins are tetrameric membrane-bound channels that facilitate transport of water and other small solutes across cell membranes. In eukaryotes, they are frequently regulated by gating or trafficking, allowing for the cell to control membrane permeability in a specific manner. Protein–protein interactions play crucial roles in both regulatory processes and also mediate alternative functions such as cell adhesion. In this review, we summarize recent knowledge about aquaporin protein–protein interactions; dividing the interactions into three types: (1 interactions between aquaporin tetramers; (2 interactions between aquaporin monomers within a tetramer (hetero-tetramerization; and (3 transient interactions with regulatory proteins. We particularly focus on the structural aspects of the interactions, discussing the small differences within a conserved overall fold that allow for aquaporins to be differentially regulated in an organism-, tissue- and trigger-specific manner. A deep knowledge about these differences is needed to fully understand aquaporin function and regulation in many physiological processes, and may enable design of compounds targeting specific aquaporins for treatment of human disease.

  16. Interactions, Starbursts, and Star Formation

    Directory of Open Access Journals (Sweden)

    Johan H. Knapen

    2015-12-01

    Full Text Available We study how interactions between galaxies affect star formation within them by considering a sample of almost 1500 of the nearest galaxies, all within a distance of ∼45 Mpc. We use the far-IR emission to define the massive star formation rate (SFR, and then normalise the SFR by the stellar mass of the galaxy to obtain the specific star formation rate (SSFR. We explore the distribution of (SSFR with morphological type and with stellar mass. We calculate the relative enhancement of SFR and SSFR for each galaxy by normalising them by the median SFR and SSFR values of individual control samples of similar non-interacting galaxies. We find that both the median SFR and SSFR are enhanced in interacting galaxies, and more so as the degree of interaction is higher. The increase is moderate, reaching a maximum of a factor of 1.9 for the highest degree of interaction (mergers. While the SFR and SSFR are enhanced statistically by interactions, in many individual interacting galaxies they are not enhanced at all. Our study is based on a representative sample of nearby galaxies and should be used to place constraints on studies based on samples of galaxies at larger distances.

  17. Luminosity monitor topics for RHIC spin and AA, and pA interactions

    International Nuclear Information System (INIS)

    Underwood, D.

    1998-01-01

    This is a note to define topics to be studied in more depth for the Luminosity monitoring for Spin Asymmetries. My numerical examples here are to stimulate discussion and should be taken with a grain of salt. The RHIC Spin experiments will require a very high degree of coordination between the experiments and the accelerator. For example see AGS/RHIC/SN 035. In this note we list some of the issues to be considered in monitoring the relative luminosity between various beam-beam spin combinations and beam-gas combinations. We give simplified numerical examples of the problems encountered in doing the luminosity monitoring to the 10 -4 level. It is hoped that this will provide a framework for serious study of these problems with simulations and other means. Many of the issues may also be relevant to pA and AA running where there may be sizable beam-gas backgrounds

  18. High Power Microwave Emission of Large and Small Orbit Gyrotron Devices in Rectangular Interaction Structures

    Science.gov (United States)

    Hochman, J. M.; Gilgenbach, R. M.; Jaynes, R. L.; Rintamaki, J. I.; Luginsland, J. W.; Lau, Y. Y.; Spencer, T. A.

    1996-11-01

    Experiments utilize large and small orbit e-beam gyrotron devices in a rectangular-cross-section (RCS) gyrotron. This device is being explored to examine polarization control. Other research issues include pulse shortening, and mode competition. MELBA generates electron beams with parameters of: -800kV, 1-10kA diode current, and 0.5-1.0 μ sec pulselengths. The small orbit gyrotron device is converted to a large orbit experiment by running MELBA's annular electron beam through a magnetic cusp. Initial experiments showed an increase in beam alpha (V_perp/V_par) of a factor of ~ 4 between small and large orbit devices. Experimental results from the RCS gyrotron will be compared for large-orbit and small-orbit electron beams. Beam transport data and frequency measurements will be presented. Computer modeling utilizing the MAGIC and E-gun codes will be shown.

  19. A laser-based beam profile monitor for the SLC/SLD interaction region

    International Nuclear Information System (INIS)

    Alley, R.; Arnett, D.; Bong, E.; Colocho, W.; Frisch, J.; Horton-Smith, S.; Inman, W.; Jobe, K.; Kotseroglou, T.; McCormick, D.; Nelson, J.; Scheeff, M.; Wagner, S.; Ross, M.C.

    1996-01-01

    Beam size estimates made using beam-beam deflections are used for optimization of the Stanford linear collider (SLC) electron-positron beam sizes. Typical beam sizes and intensities expected for 1996 operations are 2.1 x 0.6 μm (x, y) at 4.0.10 10 particles per pulse. Conventional profile monitors, such as scanning wires, fail at charge densities well below this. The laser-based profile monitor uses a finely-focused 350-nm wavelength tripled YLF laser pulse that traverses the particle beam path about 29 cm away from the e + /e - IP. Compton scattered photons and degraded e + /e - are detected as the beam is steered across the laser pulse. The laser pulse has a transverse size of 380 nm and a Rayleigh range of about 5 μm. (orig.)

  20. Calculations on Noncovalent Interactions and Databases of Benchmark Interaction Energies

    Czech Academy of Sciences Publication Activity Database

    Hobza, Pavel

    2012-01-01

    Roč. 45, č. 4 (2012), s. 663-672 ISSN 0001-4842 R&D Projects: GA ČR GBP208/12/G016 Grant - others:European Social Fund(XE) CZ.1.05/2.1.00/03.0058 Institutional research plan: CEZ:AV0Z40550506 Keywords : non-covalent interactions * covalent interactions * quantum chemical approach Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 20.833, year: 2012