WorldWideScience

Sample records for axial-vector currents

  1. Improving the lattice axial vector current

    International Nuclear Information System (INIS)

    Horsley, R.; Perlt, H.; Schiller, A.; Zanotti, J.M.

    2015-11-01

    For Wilson and clover fermions traditional formulations of the axial vector current do not respect the continuum Ward identity which relates the divergence of that current to the pseudoscalar density. Here we propose to use a point-split or one-link axial vector current whose divergence exactly satisfies a lattice Ward identity, involving the pseudoscalar density and a number of irrelevant operators. We check in one-loop lattice perturbation theory with SLiNC fermion and gauge plaquette action that this is indeed the case including order O(a) effects. Including these operators the axial Ward identity remains renormalisation invariant. First preliminary results of a nonperturbative check of the Ward identity are also presented.

  2. Renormalization of the axial-vector current in QCD

    International Nuclear Information System (INIS)

    Chiu, C.B.; Pasupathy, J.; Wilson, S.L.

    1985-01-01

    Following the method of Ioffe and Smilga, the propagation of the baryon current in an external constant axial-vector field is considered. The close similarity of the operator-product expansion with and without an external field is shown to arise from the chiral invariance of gauge interactions in perturbation theory. Several sum rules corresponding to various invariants both for the nucleon and the hyperons are derived. The analysis of the sum rules is carried out by two independent methods, one called the ratio method and the other called the continuum method, paying special attention to the nondiagonal transitions induced by the external field between the ground state and excited states. Up to operators of dimension six, two new external-field-induced vacuum expectation values enter the calculations. Previous work determining these expectation values from PCAC (partial conservation of axial-vector current) are utilized. Our determination from the sum rules of the nucleon axial-vector renormalization constant G/sub A/, as well as the Cabibbo coupling constants in the SU 3 -symmetric limit (m/sub s/ = 0), is in reasonable accord with the experimental values. Uncertainties in the analysis are pointed out. The case of broken flavor SU 3 symmetry is also considered. While in the ratio method, the results are stable for variation of the fiducial interval of the Borel mass parameter over which the left-hand side and the right-hand side of the sum rules are matched, in the continuum method the results are less stable. Another set of sum rules determines the value of the linear combination 7F-5D to be roughly-equal0, or D/(F+D)roughly-equal(7/12). .AE

  3. High-energy manifestations of heavy quarks in axial-vector neutral currents

    International Nuclear Information System (INIS)

    Kizukuri, Y.; Ohba, I.; Okano, K.; Yamanaka, Y.

    1981-01-01

    A recent work by Collins, Wilczek, and Zee has attempted to manifest the incompleteness of the decoupling theorem in the axial-vector neutral currents at low energies. In the spirit of their work, we calculate corrections of the axial-vector neutral currents by virtual-heavy-quark exchange in the high-energy e + e - processes and estimate some observable quantities sensitive to virtual-heavy-quark masses which may be compared with experimental data at LEP energies

  4. Flavor-singlet axial-vector current in quark model within background field

    International Nuclear Information System (INIS)

    Chen Kun; Yan Mulin

    1993-01-01

    The flavor-singlet axial-vector current is calculated in a quark model within pseudoscalar background-field through the Seeley-DeWitt coefficients. This current is responsible for the quark spin content of proton and is of O(1) in the large-N e expansion

  5. Plasma neutrino energy loss due to the axial-vector current at the late stages of stellar evolution

    International Nuclear Information System (INIS)

    Liu Jingjing

    2009-01-01

    Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axial-vector contributions are studied. A ratable factor of the rates from the axial-vector current relative to those of the total neutrino energy loss rates is accurately calculated. The results show that the ratable factor will reach a maximum of 0.95 or even more at relatively higher temperature and lower density (such as ρ/μ e 7 g/cm 3 ). Thus the rates of the axial-vector contribution cannot be neglected. On the other hand, the rates of the axial-vector contribution are on the order of ∼0.01% of the total vector contribution, which is in good agreement with Itoh's at relatively high density (such as ρ/μ e > 10 7 g/cm 3 ) and a temperature of T≤10 11 K. (authors)

  6. Extended partially conserved axial-vector current hypothesis and model-dependent results

    International Nuclear Information System (INIS)

    Dominguez, C.A.

    1977-01-01

    The corrections to Goldberger-Treiman relations for ΔS = 0 and vertical-bardeltaSvertical-bar = 1 β decays (Δ/sub π/and Δ/sub K/, respectively) are estimated from a Veneziano-type model for three-point functions. The effect of unitarizing the model is also discussed, and it turns out that Δ/sub π/and Δ/sub K/ are almost insensitive to a variation in the widths of the pseudoscalar-meson daughters. Moreover, the predictions for Δ/sub π/and Δ/sub K/ are in close agreement with experiment. Finally, on-mass-shell extrapolation factors for chiral anomalies in eta → γγ and eta → π + π - γ are also derived, and agreement with experiment is found without the need for invoking eta-eta' mixing. In summary, the model discussed here seems to be a suitable implementation of the recently proposed extended partially conserved axial-vector current hypothesis

  7. Applications of the conserved vector current theory and the partially conserved axial-vector current theory to nuclear beta-decays

    International Nuclear Information System (INIS)

    Tint, M.

    The contribution of the mesonic exchange effect to the conserved vector current in the first forbidden β-decay of Ra E is estimated under the headings: (1) The conserved vector current. (2) The CVC theory and the first forbidden β-decays. (3) Shell model calculations of some matrix-elements. (4) Direct calculation of the exchange term. Considering the mesonic exchange effect in the axial vector-current of β-decay the partially conserved axial vector current theory and experimental results of the process p + p → d + π + are examined. (U.K.)

  8. Axial vector mass spectrum and mixing angles

    International Nuclear Information System (INIS)

    Caffarelli, R.V.; Kang, K.

    1976-01-01

    Spectral sum rules of the axial-vector current and axial-vector current-pseudoscalar field are used to study the axial-vector mass spectrum and mixing angles, as well as the decay constants and mixing angles of the pseudoscalar mesons. In general, the result is quite persuasive for the existence of the Jsup(PC) = 1 ++ multiplet in which one has a canonical D-E mixing. (Auth.)

  9. Ω- and Σ+→pγ nonleptonic weak decays via current algebra, partial conservation of axial-vector current, and the quark model

    International Nuclear Information System (INIS)

    Scadron, M.D.; Visinescu, M.

    1983-01-01

    By employing the current-algebra--PCAC (partial conservation of axial-vector current) program at the hadron level, the three decays Ω - →Ψ 0 π - , Ψ - π 0 , ΛK - are reasonably described in terms of only one fitted (ΔI = (1/2))/(ΔI = (3/2)) parameter of expected small 6% magnitude. Other parameters needed in the analysis, the baryon octet and decuplet weak transitions , , and , are completely constrained from B→B'π weak decays and independently from the quark model. The Σ + →pγ radiative decay amplitude and asymmetry parameters are then determined in terms of no free parameters

  10. Nonperturbative Aspects of Axial Vector Vertex

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; CHEN Xiang-Song; WANG Fan; CHANG Chao-Hsi; ZHAO En-Guang

    2002-01-01

    It is shown how the axial vector current of current quarks is related to that of constituent quarks within the framework of the global color symmetry model.Gluon dressing of the axial vector vertex and the quark self-energy functions are described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger Dyson equation in the rainbow approximation,respectively.

  11. Below-unitarity-threshold branch cut in the left angle anti q q right angle coefficient of the axial-vector two-current correlation function

    International Nuclear Information System (INIS)

    Elias, V.; Univ. of Western Ontario, London, ON; Murison, J.L.; Scadron, M.D.; Steele, T.G.

    1993-01-01

    The dimension-3 quark-condensate component of the flavour-diagonal axial-vector two-current correlation function is evaluated to all orders in the quark mass m qk through use of the quark-condensate component of the nonperturbative fermion propagator. The result obtained is analytic in p 2 except for a branch cut for 0 2 qk ) 2 , corresponding to a branch cut occurring helow the anti qq kinematic threshold. The deep Euclidean region of the longitudinal component of this correlation function is utilized to obtain leading and subleading contributions to the QCD sum-rule relating m qk to . These same sum-rule results are obtained by means of an alternative derivation involving integration over the discontinuity in the correlation function along the branch cut, demonstrating the consistency of the physical-momentum-region branch cut with results obtained via standard means in the deep Euclidean region. (orig.)

  12. On-mass-shell current algebra and the π0 → 2γ decay and partial conservation of axial-vector current anomaly

    International Nuclear Information System (INIS)

    Golestaneh, A.A.

    1974-01-01

    Using the algebra of the axial vector current which is defined as a source for the pion field, the π 0 yields decay rate and the Adler anomaly are studied. The treatment is identical with the one previously applied to the other interactions which are mentioned. It consists of expressing the reduction formula in terms of the above current and evaluating it directly on the mass-shell. In the process, one has a set of intermediate states from which the one and two-mesons states are chosen. The 3π continuum is taken into account, effectively by a pion isobar. Hence the π 0 amplitude is expressed in terms of the parameters of the rho, ω, phi and π' and a coefficient β which represents the momentum dependence of the coupling constants of these mesons, at the π γ vertex. A feature of the method is that it does not explicitly depend on the anomaly operator. However, by writing the current in terms of the modified PCAC operator, the π 0 lifetime is linked with the anomaly, via these meson data and two unknown parameters, in addition the β, which represents the π contributions in the lifetime and the chiral symmetry breaking terms underlying the PCAC relation. The most economical combinations of these parameters are given for obtaining the observed π 0 lifetime in accord with the anomaly given by either of the existing quark theoretical models. It is found that, unlike in the PCAC application, one can reach this objective by a current approach without the need for the π field in the chiral symmetry breaking terms. (U.S.)

  13. Perturbative determination of mass-dependent renormalization and improvement coefficients for the heavy-light vector and axial-vector currents with relativistic heavy and domain-wall light quarks

    International Nuclear Information System (INIS)

    Yamada, Norikazu; Aoki, Sinya; Kuramashi, Yoshinobu

    2005-01-01

    We determine the mass-dependent renormalization as well as improvement coefficients for the heavy-light vector and axial-vector currents consisting of the relativistic heavy and the domain-wall light quarks through the standard matching procedure. The calculation is carried out perturbatively at the one-loop level to remove the systematic error of O(α s (am Q ) n ap) as well as O(α s (am Q ) n ) (n>=0), where p is a typical momentum scale in the heavy-light system. We point out that renormalization and improvement coefficients of the heavy-light vector current agree with those of the axial-vector current, thanks to the exact chiral symmetry for the light quark. The results obtained with three different gauge actions, plaquette, Iwasaki and DBW2, are presented as a function of heavy quark mass and domain-wall height

  14. Topological invariants and the dynamics of an axial vector torsion field

    International Nuclear Information System (INIS)

    Drechsler, W.

    1983-01-01

    A generalized throry of gravitation is discussed which is based on a Riemann-Cartan space-time, U 4 , with an axial vector torsion field. Besides Einstein's equations determining the metric of the U 4 a system of nonlinear field equations is established coupling an axial vector source current to the axial vector torsion field. The properties of the solutions of these equations are discussed assuming a London-type condition relating the axial current and torsion field. To characterize the solutions use is made of the Euler and Pontrjagin forms and the associated quadratic curvature invariants for the U 4 space-time. It is found that there exists for a Riemann-Cartan space-time a relation between the zeros of the axial vector torsion field and the singularities of the Pontrjagin invariant, which is analogous to the well-known Hopf relation between the zeros of vector fields and the Euler characteristic. (author)

  15. Gauge anomaly with vector and axial-vector fields in 6D curved space

    Science.gov (United States)

    Yajima, Satoshi; Eguchi, Kohei; Fukuda, Makoto; Oka, Tomonori

    2018-03-01

    Imposing the conservation equation of the vector current for a fermion of spin 1/2 at the quantum level, a gauge anomaly for the fermion coupling with non-Abelian vector and axial-vector fields in 6D curved space is expressed in tensorial form. The anomaly consists of terms that resemble the chiral U(1) anomaly and the commutator terms that disappear if the axial-vector field is Abelian.

  16. Quasi-renormalization of the axial vector model

    International Nuclear Information System (INIS)

    Schweda, M.

    1979-01-01

    Using the regulator-free BPHZL renormalization scheme the problem of anomalies in a massive axial vector meson model is reinvestigated. The Adler-Bardeen-Bell-Jackiw anomaly introduces some impressive modifications: the nontrivial self-energy and the counterterm of the longitudinal part of the axial vector field depend on the anomaly via the anomalous Ward identity. The investigations are based on a Fermi-type gauge. (author)

  17. Is a charmed axial-vector meson already found

    International Nuclear Information System (INIS)

    Matsuda, S.

    1976-12-01

    A calculation is presented of the production rate via e + e - annihilation for a charmed p-wave meson of Jsup(P) = 1 + , based on a non-relativistic quark model of charmed hadrons. The results strongly suggest that the charmed axial-vector meson should be found copiously in association with a ground-state charmed meson. (author)

  18. Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar

    International Nuclear Information System (INIS)

    Gandini, Paolo

    2012-01-01

    We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f L in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f L ∼ 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B → ρρ and B + → (Omega)ρ + decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f L ∼ 0.5 in B → φK* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.

  19. Vector and axial-vector charmoniumlike states

    Science.gov (United States)

    Chen, Wei; Zhu, Shi-Lin

    2011-02-01

    After constructing all the tetraquark interpolating currents with JPC=1-+, 1--, 1++ and 1+- in a systematic way, we investigate the two-point correlation functions to extract the masses of the charmoniumlike states with QCD sum rule. For the 1-- qcq¯c¯ charmoniumlike state, mX=4.6˜4.7GeV, which implies a possible tetraquark interpretation for the state Y(4660). The masses for both the 1++ qcq¯c¯ and scs¯c¯ charmoniumlike states are around 4.0˜4.2GeV, which are slightly above the mass of X(3872). For the 1-+ and 1+- qcq¯c¯ charmoniumlike states, the extracted masses are around 4.5˜4.7GeV and 4.0˜4.2GeV, respectively. As a by-product, the bottomoniumlike states are also studied. We also discuss the possible decay modes and experimental search of the charmoniumlike states.

  20. New QCD sum rules for nucleon axial-vector coupling constants

    International Nuclear Information System (INIS)

    Lee, F.X.; Leinweber, D.B.; Jin, X.

    1997-01-01

    Two new sets of QCD sum rules for the nucleon axial-vector coupling constants are derived using the external-field technique and generalized interpolating fields. An in-depth study of the predicative ability of these sum rules is carried out using a Monte Carlo based uncertainty analysis. The results show that the standard implementation of the QCD sum rule method has only marginal predicative power for the nucleon axial-vector coupling constants, as the relative errors are large. The errors range from approximately 50% to 100% compared to the nucleon mass obtained from the same method, which has only a 10%- 25% error. The origin of the large errors is examined. Previous analyses of these coupling constants are based on sum rules that have poor operator product expansion convergence and large continuum contributions. Preferred sum rules are identified and their predictions are obtained. We also investigate the new sum rules with an alternative treatment of the problematic transitions which are not exponentially suppressed in the standard treatment. The alternative treatment provides exponential suppression of their contributions relative to the ground state. Implications for other nucleon current matrix elements are also discussed. copyright 1997 The American Physical Society

  1. Constraining vectors and axial-vectors in walking technicolour by a holographic principle

    DEFF Research Database (Denmark)

    D. Dietrich, Dennis; Kouvaris, Christoforos

    2008-01-01

    We use a holographic principle to study the low-energy spectrum of walking technicolour models. In particular, we predict the masses of the axial vectors as well as the decay constants of vectors and axial vectors as functions of the mass of the techni-rho. Given that there are very few...

  2. Effective axial-vector strength and β-decay systematics

    Science.gov (United States)

    Delion, D. S.; Suhonen, J.

    2014-09-01

    We use the weak axial-vector coupling strength g_{\\text{A}} as a key parameter to reproduce simultaneously the available data for both the Gamow-Teller \\beta^- and \\beta^+/\\text{EC} decay rates in nine triplets of isobars with mass numbers A=70,78,100,104,106,110,116,128,130 . We use the proton-neutron quasiparticle random-phase approximation (pnQRPA) with schematic dipole interaction containing particle-particle and particle-hole parts with mass-dependent strengths. Our analysis points to a strongly quenched effective value g_{\\text{A}}\\approx 0.3 , with a relative error of 28%. We then perform a systematic computation of 218 experimentally known \\beta^- and \\beta^+/\\text{EC} decays with quite a remarkable success. The presently extracted value of g_{\\text{A}} should be taken as an effective one, specific for a given nuclear theory framework. Present studies suggest that the effective g_{\\text{A}} is suitable for the description of decay transitions to 1^+ states at moderate excitation, below the Gamow-Teller giant resonance region.

  3. Dispersion approach to anomalies in the axial-vector Ward-Takahashi identities

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, K. Sasaki, R. (Tokyo Univ. (Japan). Dept. of Physic)

    1975-01-01

    On the basis of dispersion relations and unitarity anomalous Ward-Takahashi identities for the axial-vector current are derived in quantum electrodynamics. In this derivation use of divergent unrenormalized expressions is intentionally avoided, and only finite renormalized expressions are employed from the start. The origin of the anormalies is attributed to a mismatch of the subtraction conditions present in the naive Ward-Takahashi identities. The resulting anomalous Ward-Takahashi identities are valid in every order of the perturbation expansion and can be cast in the form of an operator equation. In the course of this derivation we encounter the problem of how to regularize operator products and a possible solution of this problem is provided in terms of subtraction conditions.

  4. Dispersion approach to anomalies in the axial-vector Ward-Takahashi identities

    International Nuclear Information System (INIS)

    Nishijima, Kazuhiko; Sasaki, Ryu

    1975-01-01

    On the basis of dispersion relations and unitarity anomalous Ward-Takahashi identities for the axial-vector current are derived in quantum electrodynamics. In this derivation use of divergent unrenormalized expressions is intentionally avoided, and only finite renormalized expressions are employed from the start. The origin of the anormalies is attributed to a mismatch of the subtraction conditions present in the naive Ward-Takahashi identities. The resulting anomalous Ward-Takahashi identities are valid in every order of the perturbation expansion and can be cast in the form of an operator equation. In the course of this derivation we encounter the problem of how to regularize operator products and a possible solution of this problem is provided in terms of subtraction conditions. (auth.)

  5. The contribution of axial-vector mesons to hyperfine structure of muonic hydrogen

    OpenAIRE

    Dorokhov, A. E.; Kochelev, N. I.; Martynenko, A. P.; Martynenko, F. A.; Radzhabov, A. E.

    2017-01-01

    The contribution from the axial-vector meson exchange to the potential of the muon–proton interaction in muonic hydrogen induced by anomalous axial-vector meson coupling to two photon state is calculated. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is large and important for a comparison with precise experimental data. In the light of our result, the proton radius “puzzle” is discussed.

  6. On the Reduction of Vector and Axial-Vector Fields in a Meson Effective Action at O(p4)

    International Nuclear Information System (INIS)

    Bel'kov, A.A.; Lanev, A.V.; Schaale, A.

    1994-01-01

    Starting from an effective NJL-type quark interaction we have derived an effective meson action for the pseudoscalar sector. The vector and axial-vector degrees of freedom have been integrated out, applying the static equations of motion. As the results we have found a (reduced) pseudoscalar meson Lagrangian of the Gasser-Leutwyler type with modified structure coefficients L i . This method has been also used to construct the reduced weak and electromagnetic-weak currents. The application of the reduced Lagrangian and currents has been considered in physical processes. 36 refs., 1 fig., 1 tab

  7. Masses of scalar and axial-vector B mesons revisited

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hai-Yang [Academia Sinica, Institute of Physics, Taipei (China); Yu, Fu-Sheng [Lanzhou University, School of Nuclear Science and Technology, Lanzhou (China)

    2017-10-15

    The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the q anti q quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and 1{sup +} charmonium-like state X(3872). A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, D{sub s0}{sup *} and D{sub 0}{sup *0}, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of D{sub s0}{sup *} and D{sub 0}{sup *0} masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of B{sub s0}{sup *} and B{sub 0}{sup *0} mesons. The P{sub 0}{sup *}P{sub 1}{sup '} interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and 1/m{sub Q} effects, we obtain the masses of B{sup *}{sub (s)0} and B{sup '}{sub (s)1} mesons, for example, M{sub B{sub s{sub 0{sup *}}}} = (5715 ± 1) MeV + δΔ{sub S}, M{sub B}{sup {sub '{sub s{sub 1}}}} = (5763 ± 1) MeV + δΔ{sub S} with δΔ{sub S} being 1/m{sub Q} corrections. We find that the predicted mass difference of 48 MeV between B{sup '}{sub s1} and B{sub s0}{sup *} is larger than that of 20-30 MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of M{sub B}{sup {sub '{sub s{sub 1}}}} and M{sub B}{sup {sub '{sub 1}}} is much smaller than the quark model expectation of 60-100 MeV. Experimentally, it is important to have a precise

  8. Baryon axial-vector couplings and SU(3)-symmetry breaking in chiral quark models

    International Nuclear Information System (INIS)

    Horvat, D.; Ilakovac, A.; Tadic, D.

    1986-01-01

    SU(3)-symmetry breaking is studied in the framework of the chiral bag models. Comparisons are also made with the MIT bag model and the harmonic-oscillator quark model. An important clue for the nature of the symmetry breaking comes from the isoscalar axial-vector coupling constant g/sub A//sup S/ which can be indirectly estimated from the Bjorken sum rules for deep-inelastic scattering. The chiral bag model with two radii reasonably well accounts for the empirical values of g/sub A//sup S/ and of the axial-vector coupling constants measured in hyperon semileptonic decays

  9. Observation of a New Narrow Axial-Vector Meson alpha(1)(1420)

    Czech Academy of Sciences Publication Activity Database

    Adolph, C.; Akhunzyanov, R.; Alexeev, M.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bisplinghoff, J.; Bodlák, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Chang, W.-C.; Chiosso, M.; Choi, I.; Chung, S. U.; Cicuttin, A.; Crespo, M.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse-Perdekapm, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, E.; Hinterberger, F.; Horikawa, N.; d´Hose, N.; Hsieh, C.-Yu.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jarý, V.; Jörg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.; Marchand, C.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Nový, J.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pešek, M.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmeing, S.; Schmidt, K.; Schlüter, T.; Selyunin, A.; Schmieden, H.; Schönning, K.; Schopferer, S.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Šulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Wallner, S.; Weisrock, T.; Wilfert, M.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-01-01

    Roč. 115, č. 8 (2015), 082001:1-6 ISSN 0031-9007 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : COMPASS * pion-nucleon scattering * hadron spectroscopy * light-meson spectrum * axial-vector mesons * exotic mesons Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.645, year: 2015

  10. Two-dimensional gauge model with vector U(1) and axial-vector U(1) symmetries

    International Nuclear Information System (INIS)

    Watabiki, Y.

    1989-01-01

    We have succeeded in constructing a two-dimensional gauge model with both vector U(1) and axial-vector U(1) symmetries. This model is exactly solvable. The Schwinger term vanishes in this model as a consequence of the above symmetries, and negative-norm states appear. However, the norms of physical states are always positive semidefinite due to the gauge symmetries

  11. Heavy Scalar, Vector, and Axial-Vector Mesons in Hot and Dense Nuclear Medium

    Directory of Open Access Journals (Sweden)

    Arvind Kumar

    2014-01-01

    Full Text Available In this work we shall investigate the mass modifications of scalar mesons (D0; B0, vector mesons (D*; B*, and axial-vector mesons (D1; B1 at finite density and temperature of the nuclear medium. The above mesons are modified in the nuclear medium through the modification of quark and gluon condensates. We will find the medium modification of quark and gluon condensates within chiral SU(3 model through the medium modification of scalar-isoscalar fields σ and ζ at finite density and temperature. These medium modified quark and gluon condensates will further be used through QCD sum rules for the evaluation of in-medium properties of the above mentioned scalar, vector, and axial vector mesons. We will also discuss the effects of density and temperature of the nuclear medium on the scattering lengths of the above scalar, vector, and axial-vector mesons. The study of the medium modifications of the above mesons may be helpful for understanding their production rates in heavy-ion collision experiments. The results of present investigations of medium modifications of scalar, vector, and axial-vector mesons at finite density and temperature can be verified in the compressed baryonic matter (CBM experiment of FAIR facility at GSI, Germany.

  12. Open charm-bottom axial-vector tetraquarks and their properties

    Energy Technology Data Exchange (ETDEWEB)

    Agaev, S.S. [Baku State University, Institute for Physical Problems, Baku (Azerbaijan); Azizi, K. [Dogus University, Department of Physics, Istanbul (Turkey); Sundu, H. [Kocaeli University, Department of Physics, Izmit (Turkey)

    2017-05-15

    The charged axial-vector J{sup P} = 1{sup +} tetraquarks Z{sub q} = [cq][ anti b anti q] and Z{sub s} = [cs][ anti b anti s] with the open charm-bottom contents are studied in the diquark-antidiquark model. The masses and meson-current couplings of these states are calculated by employing a QCD two-point sum rule approach, where the quark, gluon and mixed condensates up to eight dimensions are taken into account. These parameters of the tetraquark states Z{sub q} and Z{sub s} are used to analyze the vertices Z{sub q}B{sub c}ρ and Z{sub s}B{sub c}φ to determine the strong g{sub Z{sub qB{sub cρ}}} and g{sub Z{sub sB{sub cφ}}} couplings. For these purposes, the QCD light-cone sum rule method and its soft-meson approximation are utilized. The couplings g{sub Z{sub qB{sub cρ}}} and g{sub Z{sub sB{sub cφ}}}, extracted from this analysis, are applied for evaluating the strong Z{sub q} → B{sub c}ρ and Z{sub s} → B{sub c}φ decays' widths, which are essential results of the present investigation. Our predictions for the masses of the Z{sub q} and Z{sub s} states are confronted with similar results available in the literature. (orig.)

  13. Resonance X(5568) as an exotic axial-vector state

    Energy Technology Data Exchange (ETDEWEB)

    Agaev, S.S. [Baku State University, Institute for Physical Problems, Baku (Azerbaijan); Azizi, K. [Dogus University, Department of Physics, Istanbul (Turkey); Barsbay, B.; Sundu, H. [Kocaeli University, Department of Physics, Izmit (Turkey)

    2017-01-15

    The mass and meson-current coupling constant of the resonance X(5568), as well as the width of the decay X(5568) → B{sub s}{sup *}π are calculated by modeling the exotic X(5568) resonance as a diquark-antidiquark state X{sub b} = [su][bd] with quantum numbers J{sup P} = 1{sup +}. The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex X{sub b}B{sub s}{sup *}π and extract the strong coupling g{sub X{sub bB{sub s{sup *}π}}}, which is a necessary ingredient to find the width of the X{sub b} → B{sub s}{sup *}π{sup +} decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works. (orig.)

  14. The contribution of pseudoscalar and axial-vector mesons to hyperfine structure of muonic hydrogen

    OpenAIRE

    Dorokhov, A. E.; Kochelev, N. I.; Martynenko, A. P.; Martynenko, F. A.; Radzhabov, A. E.; Faustov, R. N.

    2017-01-01

    In the framework of the quasipotential method in quantum electrodynamics we calculate the contribution of light pseudoscalar (PS) and axial-vector (AV) mesons to the interaction operator of a muon and a proton in muonic hydrogen atom. The coupling of mesons with the muon is via two-photon intermediate state. The parametrization of the transition form factor of two photons into PS and AV mesons, based on the experimental data on the transition form factors and QCD asymptotics, is used. Numeric...

  15. Parity-Violating Electron Deuteron Scattering and the Proton's Neutral Axial Vector Form Factor

    International Nuclear Information System (INIS)

    Ito, T.

    2003-01-01

    The authors report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at the backward angles at electron beam energy of 125 MeV [Q 2 =0.038 (GeV/c) 2 ]. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon. In addition to the tree level amplitude associated with Z-exchange, the neutral weak axial vector form factor as measured in electron scattering can potentially receive large electroweak corrections, including the anapole moment, that are absent in neutrino scattering. The measured asymmetry A -3.51 ± 0.57 (stat) ± 0.58 (sys) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at 200 MeV [Q 2 = 0.091 (GeV/c) 2 ] on a deuterium target. The updated results are also consistent with theoretical predictions on the neutral weal axial vector form factor

  16. Axial-vector gluons and the fine structure of heavy quark--antiquark systems

    International Nuclear Information System (INIS)

    Feinberg, G.; Lynn, B.; Sucher, J.

    1979-01-01

    We point out that two models of the origin of spin-dependent forces in heavy quark systems make very different predictions about the relative size of these forces in c-barc and b-barb. The model in which these forces are relativistic corrections to vector or scalar gluon exchange predicts smaller spin-dependent effects in b-barb than in c-barc while a model in which these forces are due to exchange of axial-vector gluons predicts a similar size for spin-dependent splittings in the two systems

  17. Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons

    International Nuclear Information System (INIS)

    Liu, J.; Mendenhall, M. P.; Carr, R.; Filippone, B. W.; Hickerson, K. P.; Perez Galvan, A.; Russell, R.; Holley, A. T.; Hoagland, J.; VornDick, B.; Back, H. O.; Pattie, R. W. Jr.; Young, A. R.; Bowles, T. J.; Clayton, S.; Currie, S.; Hogan, G. E.; Ito, T. M.; Makela, M.; Morris, C. L.

    2010-01-01

    A precise measurement of the neutron decay β asymmetry A 0 has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A 0 =-0.119 66±0.000 89 -0.00140 +0.00123 , from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g A /g V =-1.275 90 -0.00445 +0.00409 .

  18. Electromagnetic and axial-vector form factors of the quarks and nucleon

    Science.gov (United States)

    Dahiya, Harleen; Randhawa, Monika

    2017-11-01

    In light of the improved precision of the experimental measurements and enormous theoretical progress, the nucleon form factors have been evaluated with an aim to understand how the static properties and dynamical behavior of nucleons emerge from the theory of strong interactions between quarks. We have analyzed the vector and axial-vector nucleon form factors (GE,Mp,n(Q2) and GAp,n(Q2)) using the spin observables in the chiral constituent quark model (χCQM) which has made a significant contribution to the unraveling of the internal structure of the nucleon in the nonperturbative regime. We have also presented a comprehensive analysis of the flavor decomposition of the form factors (GEq(Q2), GMq(Q2) and GAq(Q2) for q = u,d,s) within the framework of χCQM with emphasis on the extraction of the strangeness form factors which are fundamental to determine the spin structure and test the chiral symmetry breaking effects in the nucleon. The Q2 dependence of the vector and axial-vector form factors of the nucleon has been studied using the conventional dipole form of parametrization. The results are in agreement with the available experimental data.

  19. Strangeness Vector and Axial-Vector Form Factors of the Nucleon

    Directory of Open Access Journals (Sweden)

    Pate Stephen

    2014-03-01

    Full Text Available A revised global fit of electroweak ep and vp elastic scattering data has been performed, with the goal of determining the strange quark contribution to the vector and axial-vector form factors of the nucleon in the momentum-transfer range 0 < Q2 < 1 GeV2. The two vector (electric and magnetic form factors GsE(Q2 and GsM(Q2 are strongly constrained by ep elastic scattering data, while the major source of information on the axial-vector form factor GsA(Q2 is vp scattering data. Combining the two kinds of data into a single global fit makes possible additional precision in the determination of these form factors, and provides a unique way to determine the strange quark contribution to the nucleon spin, ΔS , independently of leptonic deep-inelastic scattering. The fit makes use of data from the BNL-E734, SAMPLE, HAPPEx, G0, and PVA4 experiments; we will also compare the result of the fit with recent data from MiniBooNE, and anticipate how this fit can be improved when new data from MicroBooNE become available.

  20. Torsion axial vector and Yvon-Takabayashi angle: zitterbewegung, chirality and all that

    Science.gov (United States)

    Fabbri, Luca; da Rocha, Roldão

    2018-03-01

    We consider propagating torsion as a completion of gravitation in order to describe the dynamics of curved-twisted space-times filled with Dirac spinorial fields; we discuss interesting relationships of the torsion axial vector and the curvature tensor with the Yvon-Takabayashi angle and the module of the spinor field, that is the two degrees of freedom of the spinor field itself: in particular, we shall discuss in what way the torsion axial vector could be seen as the potential of a specific interaction of the Yvon-Takabayashi angle, and therefore as a force between the two chiral projections of the spinor field itself. Chiral interactions of the components of a spinor may render effects of zitterbewegung, as well as effective mass terms and other related features: we shall briefly sketch some of the analogies and differences with the similar but not identical situation given by the Yukawa interaction occurring in the Higgs sector of the standard model. We will provide some overall considerations about general consequences for contemporary physics, consequences that have never been discussed before, so far as we are aware, in the present physics literature.

  1. The Zb(10610) and Zb(10650) as axial-vector tetraquark states in the QCD sum rules

    International Nuclear Information System (INIS)

    Wang, Zhi-Gang; Huang, Tao

    2014-01-01

    In this article, we study the axial-vector mesons Z b (10610) and Z b (10650) with the Cγ μ –Cγ 5 type and Cγ μ –Cγ ν type interpolating currents, respectively, by carrying out the operator product expansion to the vacuum condensates up to dimension 10. In calculations, we explore the energy scale dependence of the QCD spectral densities of the hidden bottom tetraquark states in detail for the first time, and suggest a formula μ=√(M X/Y/Z 2 −(2M b ) 2 ) with the effective mass M b =5.13 GeV to determine the energy scales. The numerical results favor assigning the Z b (10610) and Z b (10650) as the Cγ μ –Cγ 5 type and Cγ μ –Cγ ν type hidden bottom tetraquark states, respectively. We obtain the mass of the J PC =1 ++ hidden bottom tetraquark state as a byproduct, which can be compared to the experimental data in the futures. Furthermore, we study the strong decays Z b ± (10610)→ϒπ ± ,η b ρ ± with the three-point QCD sum rules, the decay widths also support assigning the Z b (10610) as the Cγ μ –Cγ 5 type hidden bottom tetraquark state

  2. Properties of vector and axial-vector mesons from a generalized Nambu-Jona-Lasinio model

    International Nuclear Information System (INIS)

    Bernard, V.; Meissner, U.G.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge

    1988-01-01

    We construct a generalized Nambu-Jona-Lasinio lagrangian including scalar, pseudoscalar, vector and axial-vector mesons. We specialize to the two-flavor case. The properties of the structured vacuum as well as meson masses and coupling constants are calculated giving an overall agreement within 20% of the experimental data. We investigate the meson properties at finite density. In contrast to the mass of the scalar σ-meson, which decreases sharply with increasing density, the vector meson masses are almost independent of density. Furthermore, the vector-meson-quark coupling constants are also stable against density changes. We point out that these results imply a softening of the nuclear equation of state at high densities. Furthermore, we discuss the breakdown of the KFSR relation on the quark level as well as other deviations from phenomenological concepts such as universality and vector meson dominance. (orig.)

  3. Rare Hadronic B Decays to Vector, Axial-Vector and Tensors

    International Nuclear Information System (INIS)

    Gao, Y.Y.

    2011-01-01

    The authors review BABAR measurements of several rare B decays, including vector-axial-vector decays B ± → φK 1 ± (1270), B ± → φ K 1 ± (1400) and B ± → b 1 # -+ρ# ± , vector-vector decays B ± → φK* ± (1410), B 0 → K* 0 (bar K)* 0 , B 0 → K*0K*0 and B 0 → K*+K*-, vector-tensor decays B ± → φK* 2 (1430) ± and φK 2 (1770)/ ± (1820), and vector-scalar decays B ± → φK* 0 (1430) ± . Understanding the observed polarization pattern requires amplitude contributions from an uncertain source.

  4. Axial vector diquark correlations in the nucleon: structure functions and static properties

    Energy Technology Data Exchange (ETDEWEB)

    Mineo, H. E-mail: mineo@nt.phys.s.u-tokyo.ac.jp; Bentz, W.; Ishii, N.; Yazaki, K

    2002-06-03

    In order to extract information on the strength of quark-quark correlations in the axial vector (a.v.) diquark channel (J{sup P}=1{sup +},T=1), we analyze the quark light cone momentum distributions in the nucleon, in particular their flavor dependencies, and the static properties of the nucleon. To construct the nucleon as a relativistic 3-quark bound state, we use a simple 'static' approximation to the full Faddeev equation in the Nambu-Jona-Lasinio model, including correlations in the scalar (J{sup P}=0{sup +},T=0) and a.v. diquark channels. It is shown that the a.v. diquark correlations should be rather weak compared to the scalar ones. From our analysis we extract information on the strength of the correlations as well as on the probability of the a.v. diquark channel.

  5. Determination of the ratio of axial-vector-to-vector weak coupling constants for beta decay of triton

    CERN Document Server

    Akulov, Y A

    2002-01-01

    Data on the chemical shifts of half-lives for atomic and molecular tritium were used to determine the ratio of axial-vector-to-vector weak coupling constants for beta decay of triton (G sub A /G sub V) sub t = -1.2646 +- 0.0035

  6. Determination of the axial-vector form factor in the radiative decay of the pion

    International Nuclear Information System (INIS)

    Ortendahl, D.A.

    1976-12-01

    The branching ratio for the decay π → eνγ was measured in a counter experiment in which the e + was detected in a magnetic spectrometer and the γ-ray in a lead glass hodoscope. The number of observed events is 226.2 +- 22.4. The branching ratio into the phase space with electron momentum above 56 MeV/c and the electron/photon opening angle greater than 132 0 is found to be (5.6 +- 0.7) x 10 -8 . From the measured branching ratio one determines γ, the ratio of the axial vector to vector form factor. The vector form factor is computed using CVC and the π 0 lifetime. For T/sub π/ 0 = 0.828 x 10 -16 sec, γ = 0.44 +- 0.12 or γ = --2.36 +- 0.12 is obtained. A comparison between the measured values of γ and various theories is made

  7. Measurement of the Strong Coupling Constant $\\alpha_s$ and the Vector and Axial-Vector Spectral Functions in Hadronic Tau Decays

    CERN Document Server

    Ackerstaff, K; Allison, J; Altekamp, N; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Bartoldus, R; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bird, S D; Blobel, Volker; Bloodworth, Ian J; Bobinski, M; Bock, P; Böhme, J; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brown, R M; Burckhart, Helfried J; Burgard, C; Bürgin, R; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Davis, R; De Jong, S; del Pozo, L A; de Roeck, A; Desch, Klaus; Dienes, B; Dixit, M S; Doucet, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Eatough, D; Estabrooks, P G; Etzion, E; Evans, H G; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Fiedler, F; Fierro, M; Fischer, H M; Fleck, I; Folman, R; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon, J; Gascon-Shotkin, S M; Geich-Gimbel, C; Geralis, T; Giacomelli, G; Giacomelli, P; Gibson, V; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Gross, E; Grunhaus, Jacob; Gruwé, M; Hanson, G G; Hansroul, M; Hapke, M; Hargrove, C K; Hartmann, C; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herndon, M; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hillier, S J; Hobson, P R; Höcker, Andreas; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Joly, A; Jones, C R; Jovanovic, P; Junk, T R; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Koetke, D S; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kyberd, P; Lafferty, G D; Lanske, D; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Lee, A M; Lefebvre, E; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mannelli, M; Marcellini, S; Markopoulos, C; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Menke, S; Merritt, F S; Mes, H; Meyer, J; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mir, R; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nellen, B; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Oreglia, M J; Orito, S; Pálinkás, J; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharf, F; Scharff-Hansen, P; Schieck, J; Schmitt, B; Schmitt, S; Schöning, A; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Sittler, A; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Sproston, M; Stahl, A; Stephens, K; Steuerer, J; Stoll, K; Strom, D; Ströhmer, R; Tafirout, R; Talbot, S D; Tanaka, S; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomson, M A; Von Törne, E; Torrence, E; Towers, S; Trigger, I; Trócsányi, Z L; Tsur, E; Turcot, A S; Turner-Watson, M F; Van Kooten, R; Vannerem, P; Verzocchi, M; Vikas, P; Voss, H; Wäckerle, F; Wagner, A; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Yekutieli, G; Zacek, V; Zer-Zion, D

    1999-01-01

    The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant alpha_s, the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives alpha_s(mtau**2) = 0.348 +- 0.009 +- 0.019 at the tau-mass scale and alpha_s(mz**2) = 0.1219 +- 0.0010 +- 0.0017 at the Z-mass scale. The values obtained for alpha_s(mz**2) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3% and 4.1% smaller, respectively. The running of the strong coupling between s_0 ~1.3 GeV**2 and s_0 = mtau**2 has been tested from direct fits to the integrated differential hadronic decay rate R_tau. A test of the saturation of QCD sum rules at the tau-mass scale has been...

  8. Effective axial-vector coupling of the gluon and top-quark charge asymmetry at the LHC

    International Nuclear Information System (INIS)

    Gabrielli, E.; Giammanco, A.; Racioppi, A.; Raidal, M.

    2012-01-01

    We study the top quark charge asymmetry induced by an effective axial-vector coupling of the gluon at the LHC experiments. We showed that rapidity cut-dependent asymmetries are more sensitive to the new physics than the independent ones. We also study the dependence of the asymmetries and variations of the total tt-bar cross sections on the invariant mass of the tt-bar system and show that it would be necessary to measure those quantities as functions of m tt at the LHC. If this is done, in the context of the considered new physics scenario, the 7 TeV LHC has enough sensitivity either to confirm the Tevatron top charge asymmetry anomaly or to rule it out. In the latter case the LHC will be able to put stringent constraint on the new physics scale Λ in this framework. (authors)

  9. Precision spectroscopy at COMPASS: Observation of a new (exotic) light axial vector meson and a deeper look into decay dynamics

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    High statistical accuracy has triggered the development of innovative analysis schemes not possible in previous experiments and lead to the discovery of new hadronic states. Among these is the observation of a new light (possibly exotic) axial vector meson, the interpretation of which is still open. In addition we have analyzed the pi-pi S-wave content in exclusive 3pi-events. As a result of our analysis also the interpretation of resonance structures can now be clarified using the variation of production rates with the four momentum transfer, allowing to identify resonant and non-resonant components in the spectra. In addition to the 3pi final states we will also give an overview on results obtained with other particles forming the final state and present an outlook on forthcoming results.

  10. Vector and Axial-Vector Correlators in AN Instanton-Like Quark Model

    Science.gov (United States)

    Dorokhov, Alexander E.

    The behavior of the vector Adler function at spacelike momenta is studied in the framework of a covariant chiral quark model with instanton-like quark-quark interaction. This function describes the transition between the high energy asymptotically free region of almost massless current quarks to the low energy hadronized regime with massive constituent quarks. The model reproduces the Adler function and V-A correlator extracted from the ALEPH and OPAL data on hadronic τ lepton decays, transformed into the Euclidean domain via dispersion relations. The leading order contribution from hadronic part of the photon vacuum polarization to the anomalous magnetic moment of the muon, aμ hvp(1), is estimated.

  11. Classification of exchange currents

    International Nuclear Information System (INIS)

    Friar, J.L.

    1983-01-01

    After expansion of the vector and axial vector currents in powers of (v/c), a heretofore unremarked regularity results. Meson exchange currents can be classified into types I and II, according to the way they satisfy the constraints of special relativity. The archetypes of these two categories are the impulse approximation to the vector and axial vector currents. After a brief discussion of these constraints, the (rhoπγ) and (ωsigmaγ) exchange currents are constructed and classified, and used to illustrate a number of important points which are often overlooked

  12. Global S U (3 )C×S U (2 )L×U (1 )Y linear sigma model: Axial-vector Ward-Takahashi identities and decoupling of certain heavy BSM particles due to the Goldstone theorem

    Science.gov (United States)

    Lynn, Bryan W.; Starkman, Glenn D.

    2017-09-01

    In the S U (2 )L×S U (2 )R linear sigma model with partially conserved axial-vector currents, a tower of Ward-Takahashi identities (WTI) have long been known to give relations among 1-scalar-particle-irreducible (1 -ϕ -I ) Green's functions, and among I-scalar-particle-reducible (1 -ϕ -R ) transition-matrix (T-matrix) elements for external scalars [i.e. the Brout-Englert-Higgs (BEH) scalar H , and three pseudoscalars π →]. In this paper, we extend these WTI and the resulting relations to the S U (3 )C×S U (2 )L×U (1 )Y linear sigma model including the heaviest generation of Standard Model (SM) fermions—the ungauged (i.e. global) Standard Model SMtb τ ντ G —supplemented with the minimum necessary neutrino content—right-handed neutrinos and Yukawa-coupling-induced Dirac neutrino mass—to obtain the charge-parity (C P )-conserving νDSMtb τ ντ G , and extract powerful constraints on the effective Lagrangian: e.g. showing that they make separate tadpole renormalization unnecessary, and guarantee infrared finiteness. The crucial observation is that ultraviolet quadratic divergences (UVQD), and all other relevant operators, contribute only to mπ2, a pseudo-Nambu-Goldstone boson (NGB) mass-squared, which appears in intermediate steps of calculations. A WTI between T-matrix elements (or, in this global theory equivalently the Goldstone theorem) then enforces mπ2=0 exactly for the true NGB in the spontaneous symmetry breaking (SSB) mode of the theory. The Goldstone theorem thus causes all relevant operator contributions, originating to all-loop-orders from virtual scalars H ,π → , quarks qLc;tRc;bRc and leptons lL;ντR;τR with (c =r , w , b ), to vanish identically. We show that our regularization-scheme-independent, WTI-driven results are unchanged by the addition of certain S U (3 )C×S U (2 )L×U (1 )Y heavy (MHeavy2≫|q2|,mWeak2 ) C P -conserving matter, such as originate in certain beyond the SM (BSM) models. The global axial-vector WTI

  13. Transition currents in diagonal spin basis

    International Nuclear Information System (INIS)

    Rogalev, R.N.

    1996-01-01

    Scalar and pseudoscalar densities, vector, pseudovector and tensor currents are expressed in terms of momentum and spin vectors of the corresponding particles in an explicitly covariant way. The obtained expressions are free of singularities and make it possible to draw a number of identities, which relate axial-vector, vector and tensor currents to each other. 8 refs

  14. Geometrodynamics for quarks and hadrons: the definition of currents

    International Nuclear Information System (INIS)

    Csikor, F.; Preparata, G.

    1978-01-01

    It is shown that the naive definition of the ''direct part'' of the vector and axial vector currents does not obey the necessary conservation conditions. The reasons for this failure are clarified and the precise conditions for restoring conservation are stated. Finally, an improved definition of currents is proposed and the physical interpretation is discussed

  15. Two-loop matching coefficients for heavy quark currents

    International Nuclear Information System (INIS)

    Kniehl, B.A.; Onishchenko, A.; Petersburg Nuclear Physics Institute, Gatchina; Piclum, J.H.; Karlsruhe Univ.; Steinhauser, M.

    2006-04-01

    In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory is discussed and analytical results are presented. Particular emphasis is put on the singlet diagrams. (Orig.)

  16. Why current algebra and PCAC are applicable for charmed-meson and -baryon weak decays

    International Nuclear Information System (INIS)

    Karlsen, R.E.; Scadron, M.D.

    1991-01-01

    By accounting for rapidly varying pole terms, the current-algebra--PCAC (partial conservation of axial-vector current) procedure properly measures large decay momentum corrections in charmed D + → bar K 0 π + , D + → bar K 0 K+, and Λ c + →p bar K 0 weak decays

  17. Current algebra and soft pion theorems for weak π production

    International Nuclear Information System (INIS)

    Adler, S.L.

    1976-01-01

    Beginning with definitions of vector, scalar, axial vector, pseudoscalar, and tensor current densities, equal time current commutators are derived and divergences are discussed. The partially conserved axial current (PCAC) hypothesis is formulated and used to derive the Goldberger--Treiman relation. Current algebra and the PCAC hypothesis are then employed to develop a master formula describing the reaction J + N → π + N where J is a current with four momentum k, and π is a soft pion with four momentum q. Several applications are considered: πN scattering consistency conditions, π isovector electroproduction relations, π production by an isoscalar weak neutral current, π axial vector weak production relations, and low energy theorems which combine soft pion results with knowledge of divergences of the vector or axial vector current J (which induces weak pion production). It is concluded that (1) the entire weak production amplitude is determined to zero order in q by soft pion theorems, and (2) combined relations determine corrections linear in q but of zero order in k

  18. Weak hadronic currents in compensation theory

    International Nuclear Information System (INIS)

    Pappas, R.C.

    1975-01-01

    Working within the framework of a compensation theory of strong and weak interactions, it is shown that: (1) an axial vector baryon number current can be included in the weak current algebra if certain restrictions on the K-meson strong couplings are relaxed; (2) the theory does not permit the introduction of strange currents of the chiral form V + A; and (3) the assumption that the superweak currents of the theory cannot contain certain CP conserving terms can be justified on the basis of compensation requirements

  19. Mass effects in three-point chronological current correlators in n-dimensional multifermion models

    International Nuclear Information System (INIS)

    Kucheryavyj, V.I.

    1991-01-01

    Three-types of quantities associated with three-point chronological fermion-current correlators having arbitrary Lorentz and internal structure are calculated in the n-dimensional multifermion models with different masses. The analysis of vector and axial-vector Ward identities for regular (finite) and dimensionally regularized values of these quantities is carried out. Quantum corrections to the canonical Ward identities are obtained. These corrections are generally homogenious functions of zeroth order in masses and under some definite conditions they are reduced to known axial-vector anomalies. The structure and properties of quantum corrections to AVV and AAA correlators in the four-dimension space-time are investigated in detail

  20. Neutral current in the Weinberg-Salam gauge model and elastic scattering of neutrinos and antineutrinos on nucleons

    International Nuclear Information System (INIS)

    Sidhu, D.P.

    1976-01-01

    We study the elastic scattering of neutrinos and antineutrinos on nucleons in the Weinberg-Salam model of the neutral current. In particular, we incorporate into our calculation the experimental cuts relevant to the two recent BNL experiments and also fold in the BNL ν and anti ν spectra. Sensitivity of the calculation to the changes in the axial-vector-meson mass and the Weinberg angle are explored. We conclude that the Weinberg-Salam model prediction for R/sub el/ = / and the differential-cross-section measurements are not inconsistent with the data provided the uncertainty in the mass of the axial-vector meson M/sub A/ is taken into account. Similar predictions are given for anti νN scattering

  1. Non-perturbative improvement of the axial current with three dynamical flavors and the Iwasaki gauge action

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, T.; Hashimoto, S. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan)]|[Graduate Univ. for Advanced Studies, Tsukuba, Ibaraki (Japan); Aoki, S. [Tsukuba Univ., Ibaraki (Japan). Graduate School of Pure and Applied Sciences]|[Brookhaven National Laboratory, Upton, NY (United States). Riken BNL Research Center; Della Morte, M. [CERN, Physics Dept., Geneva (Switzerland); Hoffmann, R. [Colorado Univ., Boulder, CO (United States). Dept. of Physics; Sommer, R. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2007-03-15

    We perform a non-perturbative determination of the improvement coefficient c{sub A} to remove O(a) discretization errors in the axial vector current in three-flavor lattice QCD with the Iwasaki gauge action and the standard O(a)-improved Wilson quark action. An improvement condition with a good sensitivity to c{sub A} is imposed at constant physics. Combining our results with the perturbative expansion, c{sub A} is now known rather precisely for a{sup -1}>or similar 1.6 GeV. (orig.)

  2. Non-perturbative improvement of the axial current with three dynamical flavors and the Iwasaki gauge action

    International Nuclear Information System (INIS)

    Kaneko, T.; Hashimoto, S.; Aoki, S.; Hoffmann, R.

    2007-03-01

    We perform a non-perturbative determination of the improvement coefficient c A to remove O(a) discretization errors in the axial vector current in three-flavor lattice QCD with the Iwasaki gauge action and the standard O(a)-improved Wilson quark action. An improvement condition with a good sensitivity to c A is imposed at constant physics. Combining our results with the perturbative expansion, c A is now known rather precisely for a -1 >or similar 1.6 GeV. (orig.)

  3. Coherent production of π+ and π- mesons by charged-current interactions of neutrinos and antineutrinos on neon nuclei at the Fermilab Tevatron

    Science.gov (United States)

    Aderholz, M.; Aggarwal, M. M.; Akbari, H.; Allport, P. P.; Baba, P. V.; Badyal, S. K.; Barth, M.; Baton, J. P.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Campbell, R. C.; Cence, R.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; Coutures, C.; de Prospo, D.; Devanand; de Wolf, E.; Faulkner, P. J.; Fretter, W. B.; Gupta, V. K.; Guy, J.; Hanlon, J.; Harigel, G.; Harris, F.; Jabiol, M. A.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Jones, R. W.; Kafka, T.; Kalelkar, M.; Kasper, P.; Kasper, P.; Kaul, G. L.; Kaur, M.; Kohli, J. M.; Koller, E. L.; Krawiec, R. J.; Lauko, M.; Lys, J.; Mann, W. A.; Marage, P.; Milburn, R. H.; Miller, D. B.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Neveu, M.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Sacton, J.; Saitta, B.; Schmid, P.; Schmitz, N.; Schneps, J.; Sekulin, R.; Sewell, S.; Singh, J. B.; Sood, P. M.; Smart, W.; Stamer, P.; Varvell, K. E.; Venus, W.; Verluyten, L.; Voyvodic, L.; Wachsmuth, H.; Wainstein, S.; Willocq, S.; Wittek, W.; Yost (E632 Collaboration), G. P.

    1989-11-01

    Coherent single-pion production on neon nuclei is studied using the Fermilab 15-ft bubble chamber filled with a heavy Ne-H2 mixture and exposed to the Tevatron neutrino beam. In the neutrino energy range 40-300 GeV, the net signal is 20+/-6 events, giving a corrected rate per charged-current event of (0.26+/-0.10)%. The cross section and kinematic distributions agree with the predictions of a model based on partial conservation of axial-vector current and meson dominance.

  4. Trace and Ward-Takahashi identity anomalies in an SU(3) current model with energy-momentum tensor

    International Nuclear Information System (INIS)

    Zacrep, D.B.; Young, B.

    1975-01-01

    We discuss the validity of the naive Ward-Takahashi identities and trace identities for arbitrary n-point functions (n-pf's) of scalar, pseudoscalar, vector, and axial-vector currents and the improved energy-momentum tensor, thus extending the previous investigations in a unified way. We show that the validity of the naive Ward-Takahashi identities of the energy-momentum tensor implies the satisfaction of those of the vector currents. This removes an ambiguity concerning the minimal sets of anomalous current Ward-Takahashi identities. We find that all the anomalous Ward-Takahashi identities for the broad structure of n-pf's are again restricted to the axial-vector current of n-pf's of abnormal parity in a well-defined pattern, and the trace identity anomalies occur only in normal-parity n-pf's. We give all these anomalies. Our results show that there are no new anomalies associated with the inclusion of the energy-momentum tensor in the n-pf's

  5. A one-loop study of matching conditions for static-light flavor currents

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Dirk [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Parma Univ. (Italy); Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Collaboration: ALPHA Collaboration

    2012-11-15

    Heavy Quark Effective Theory (HQET) computations of semi-leptonic decays, e.g. B{yields}{pi}l{nu}, require the knowledge of the parameters in the effective theory for all components of the heavy-light flavor currents. So far non-perturbative matching conditions have been employed only for the time component of the axial current. Here we perform a check of matching conditions for the time component of the vector current and the spatial component of the axial vector current up to one-loop order of perturbation theory and to lowest order of the 1/m-expansion. We find that the proposed observables have small higher order terms in the 1/m-series and are thus excellent candidates for a non-perturbative matching procedure.

  6. Quantum Monte Carlo calculation of neutral-current ν -12C inclusive quasielastic scattering

    Science.gov (United States)

    Lovato, A.; Gandolfi, S.; Carlson, J.; Lusk, Ewing; Pieper, Steven C.; Schiavilla, R.

    2018-02-01

    Quasielastic neutrino scattering is an important aspect of the experimental program to study fundamental neutrino properties including neutrino masses, mixing angles, mass hierarchy, and charge-conjugation parity (CP)- violating phase. Proper interpretation of the experiments requires reliable theoretical calculations of neutrino-nucleus scattering. In this paper we present calculations of response functions and cross sections by neutral-current scattering of neutrinos off 12C. These calculations are based on realistic treatments of nuclear interactions and currents, the latter including the axial, vector, and vector-axial interference terms crucial for determining the difference between neutrino and antineutrino scattering and the CP-violating phase. We find that the strength and energy dependence of two-nucleon processes induced by correlation effects and interaction currents are crucial in providing the most accurate description of neutrino-nucleus scattering in the quasielastic regime.

  7. First Measurement of the Muon Neutrino Charged Current Quasielastic Double Differential Cross Section

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A.A.; /Mexico U., CEN; Anderson, C.E.; /Yale U.; Bazarko, A.O.; /Princeton U.; Brice, S.J.; /Fermilab; Brown, B.C.; /Fermilab; Bugel, L.; /Columbia U.; Cao, J.; /Michigan U.; Coney, L.; /Columbia U.; Conrad, J.M.; /MIT; Cox, D.C.; /Indiana U.; Curioni, A.; /Yale U. /Columbia U.

    2010-02-01

    A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section (d{sup 2}{sigma}/dT{sub {mu}}d cos {theta}{sub {mu}}) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process to date. With the assumption of CCQE scattering, the absolute cross section as a function of neutrino energy ({sigma}[E{sub {nu}}]) and the single differential cross section (d{sigma}/dQ{sup 2}) are extracted to facilitate comparison with previous measurements. These quantities may be used to characterize an effective axial-vector form factor of the nucleon and to improve the modeling of low-energy neutrino interactions on nuclear targets. The results are relevant for experiments searching for neutrino oscillations.

  8. Do the weak neutral currents cause parity non-conserving eN and μN forces

    International Nuclear Information System (INIS)

    Henley, E.M.

    1977-01-01

    It is stated that although the evidence for weak neutral currents is now well established its effects have been observed primarily in reactions initiated by muon neutrinos in which the neutrino is also present in the final state. There is, as yet, no comparable evidence for a weak force due to neutral currents, mediated by an uncharged boson, between charged leptons (electrons, muons) and nucleons. Theory predicts such a force, but its detection requires it to be parity non-conserving, since any weak parity conserving force is masked by the much larger electromagnetic interaction between the charged lepton and proton. Although high energy neutrino experiments favor a parity non-conserving interaction, the evidence is not overwhelming, and pure vector current theories cannot be ruled out. The electromagnetic current which is related directly to the weak force in modern gauge theories, behaves, as a pure vector under rotations and reflections, but the charged weak currents, responsible for ordinary β decays, are known to be of a mixed vector-axial vector nature. It is therefore of great interest to learn the spatial characteristics of the neutral weak currents. The search for parity non-conserving (PNC) effects in electron-nucleon scattering, in muonic atoms and in normal electronic atoms, has received much attention, but the experiments require very high precision and great care and ingenuity. The variety of ways for searching for PNC effects are discussed, together with the basic framework for most PNC theories, restricted to vector and axial-vector currents. One method to learn about the e-N weak force is to scatter longitudinally polarized electrons from protons, and the advantages of this are discussed - such tests are being undertaken. Experiments with muonic and normal electronic atoms are referred to, and their advantages and disadvantages are discussed. It is pointed out that a pleasant feature of the weak interaction is that perturbation theory can be used

  9. Study of the space-time structure of the leptonic weak charged current by measurement of the muon polarization from the reaction anti νsub(μ)+Fe->X+μ+

    International Nuclear Information System (INIS)

    Metz, E.

    1982-01-01

    An experiment for the measurement of the longitudinal polarization of muons was performed which were produced in the deep inelastic anti ν-nucleon scattering in an irontarget (CDHS detector). The muon decay was applied as indicator of the muon polarization. As polarimeter served a marmor-scintillator calorimeter (CHARM detector). The experiment was performed in the broad-band beam of the CERN SPS. Measured was the longitudinal polarization P = 0.82 +- 0.07 (stat.) +- 0.12 (syst.). That means that the weak charged current possesses a dominant vector and/or axial-vector structure. Regarding the measuring errors of the muon polarization an upper limit for possible S-, P-, and T- contributions to the weak charged current can be stated: sigmasub(S,P,T)/sigmasub(TOT) 0.5) relatively to the muon polarization for small y (y 0.5) = 1.10 +- 0.24 (stat.). The systematic error vanishes in this relative measurement. Measured value and error lead to an upper limit for S- and/or P-contributions: sigmasub(S,P):sigmasub(TOT) 2 approx.= 4 (GeV/c) 2 ) a vector and/or axial-vector structure. (orig./HSI) [de

  10. Axial U(1) current in Grabowska and Kaplan's formulation

    Science.gov (United States)

    Hamada, Yu; Kawai, Hikaru

    2017-06-01

    Recently, Grabowska and Kaplan [Phys. Rev. Lett. 116, 211602 (2016); Phys. Rev. D 94, 114504 (2016)] suggested a nonperturbative formulation of a chiral gauge theory, which consists of the conventional domain-wall fermion and a gauge field that evolves by gradient flow from one domain wall to the other. We introduce two sets of domain-wall fermions belonging to complex conjugate representations so that the effective theory is a 4D vector-like gauge theory. Then, as a natural definition of the axial-vector current, we consider a current that generates simultaneous phase transformations for the massless modes in 4 dimensions. However, this current is exactly conserved and does not reproduce the correct anomaly. In order to investigate this point precisely, we consider the mechanism of the conservation. We find that this current includes not only the axial current on the domain wall but also a contribution from the bulk, which is nonlocal in the sense of 4D fields. Therefore, the local current is obtained by subtracting the bulk contribution from it.

  11. Observation of a new narrow axial-vector meson $a_1(1420)$

    CERN Document Server

    Adolph, C.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Dunnweber, W.; Duic, V.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse-Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Yu; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; Pesek, M.; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rychter, A.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Schluter, T.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Wallner, S.; Weisrock, T.; Wilfert, M.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-08-19

    The COMPASS collaboration at CERN has measured diffractive dissociation of 190 GeV$/c$ pions into the $\\pi^-\\pi^-\\pi^+$ final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of $3\\pi$ mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88~waves. A narrow $J^{PC} = 1^{++}$ signal is observed in the $f_0(980)\\,\\pi$ channel. We present a resonance-model study of a subset of the spin-density matrix selecting $3\\pi$ states with $J^{PC} = 2^{++}$ and $4^{++}$ decaying into $\\rho(770)\\,\\pi$ and with $J^{PC} = 1^{++}$ decaying into $f_0(980)\\,\\pi$. We identify a new $a_1$ meson with mass $(1414^{+15}_{-13})$ MeV$/c^2$ and width $(153^{+8}_{-23})$ MeV$/c^2$. Within the final states investigated in our analysis, we observe the new $a_1(1420)$ decaying only into $f_0(980)\\,\\pi$, suggesting its exotic nature. To our knowledge, such a state has never been predicted.

  12. Vector and Axial-vector resonances in composite models of the Higgs boson

    DEFF Research Database (Denmark)

    Franzosi, Diogo Buarque; Cacciapaglia, Giacomo; Cai, Haiying

    2016-01-01

    We provide a non-linear realisation of composite Higgs models in the context of the SU(4)/Sp(4) symmetry breaking pattern, where the effective Lagrangian of the spin-0 and spin-1 resonances is constructed via the CCWZ prescription using the Hidden Symmetry formalism. We investigate the EWPT const...... as a template for the phenomenology of composite Higgs models at the LHC and at future 100 TeV colliders, as well as for other application. In this work, we focus on the formalism for spin-1 resonances and their bounds from di-lepton and di-boson searches at the LHC.......We provide a non-linear realisation of composite Higgs models in the context of the SU(4)/Sp(4) symmetry breaking pattern, where the effective Lagrangian of the spin-0 and spin-1 resonances is constructed via the CCWZ prescription using the Hidden Symmetry formalism. We investigate the EWPT...... constraints by accounting the effects from reduced Higgs couplings and integrating out heavy spin-1 resonances. This theory emerges from an underlying theory of gauge interactions with fermions, thus first principle lattice results predict the massive spectrum in composite Higgs models. This model can be used...

  13. Vector and axial-vector resonances in composite models of the Higgs boson

    Energy Technology Data Exchange (ETDEWEB)

    Franzosi, Diogo Buarque [II. Physikalisches Institut, Universität Göttingen,Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Cacciapaglia, Giacomo; Cai, Haiying; Deandrea, Aldo [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL,F-69622, Villeurbanne (France); Frandsen, Mads [CP-Origins & Danish Institute for Advanced Study DIAS, University of Southern Denmark,Campusvej 55, DK-5230 Odense M (Denmark)

    2016-11-11

    We provide a non-linear realisation of composite Higgs models in the context of the SU(4)/Sp(4) symmetry breaking pattern, where the effective Lagrangian of the spin-0 and spin-1 resonances is constructed via the CCWZ prescription using the Hidden Symmetry formalism. We investigate the EWPT constraints by accounting the effects from reduced Higgs couplings and integrating out heavy spin-1 resonances. This theory emerges from an underlying theory of gauge interactions with fermions, thus first principle lattice results predict the massive spectrum in composite Higgs models. This model can be used as a template for the phenomenology of composite Higgs models at the LHC and at future 100 TeV colliders, as well as for other application. In this work, we focus on the formalism for spin-1 resonances and their bounds from di-lepton and di-boson searches at the LHC.

  14. Structure of the neutral current coupling in high energy neutrino--nucleon interactions

    International Nuclear Information System (INIS)

    Merritt, F.S.

    1977-01-01

    The primary objective of this experiment was to determine the Lorentz structure of the neutral current coupling--that is, to determine what combination of V-A and V+A (or possibly S, P, and T) components make up the neutral coupling. The experiment used the Fermilab narrow band neutrino beam to provide separated neutrino and antineutrino fluxes, each consisting of two energy bands at approximately equal to 55 and approximately equal to 150 GeV. Deep inelastic inclusive neutrino-nucleon interactions of the form ν(anti ν) + N = μ - (μ + ) + hadrons (CC event) ν(anti ν) + N = ν(anti ν) + hadrons (NC event) were observed in an instrumented steel target-calorimeter, which measured the total energy of the hadrons produced in each event. The neutral current coupling was determined by comparing the hadron energy distributions of neutrino and antineutrino neutral current events. An analysis of the charged-current data was carried out in order to determine the background of charged-current events with unobserved muons, and to provide a normalization for the neutral current data. Various parameterizations of the CC interaction were tested, and their effects on the neutral current analysis were studied in detail. The neutral current analysis indicates that, if only vector and axial-vector components exist, then the neutral current coupling lies between V and V-A. A pure scalar coupling is excluded. The data were compared to the Weinberg--Salam theory (extended to semileptonic interactions), and are in very good agreement with its predictions. Comparison of these data to the low energy Gargamelle data indicates consistency with a scaling hypothesis

  15. Nuclear effects in (anti)neutrino charge-current quasielastic scattering at MINER νA kinematics

    Science.gov (United States)

    Ivanov, M. V.; Antonov, A. N.; Megias, G. D.; González-Jiménez, R.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.; Udías, J. M.

    2018-05-01

    We compare the characteristics of the charged-current quasielastic (anti)neutrino scattering obtained in two different nuclear models, the phenomenological SuperScaling Approximation and the model using a realistic spectral function S(p, ɛ) that gives a scaling function in accordance with the (e, e‧ ) scattering data, with the recent data published by the MiniBooNE, MINER νA, and NOMAD collaborations. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals from the Jastrow correlation method and has a realistic energy dependence. Both models provide a good description of the MINER νA and NOMAD data without the need of an ad hoc increase of the value of the mass parameter in the axial-vector dipole form factor. The models considered in this work, based on the the impulse approximation (IA), underpredict the MiniBooNE data for the flux-averaged charged-current quasielastic {ν }μ ({\\bar{ν }}μ ){+}12\\text{C} differential cross section per nucleon and the total cross sections, although the shape of the cross sections is represented by the approaches. The discrepancy is most likely due to missing of the effects beyond the IA, e.g., those of the 2p–2h meson exchange currents that have contribution in the transverse responses.

  16. Measurement of the $\\beta$-asymmetry parameter of $^{67}$Cu in search for tensor type currents in the weak interaction

    CERN Document Server

    Soti, G.; Breitenfeldt, M.; Finlay, P.; Herzog, P.; Knecht, A.; Köster, U.; Kraev, I.S.; Porobic, T.; Prashanth, P.N.; Towner, I.S.; Tramm, C.; Zákoucký, D.; Severijns, N.

    2014-01-01

    Precision measurements at low energy search for physics beyond the Standard Model in a way complementary to searches for new particles at colliders. In the weak sector the most general $\\beta$ decay Hamiltonian contains, besides vector and axial-vector terms, also scalar, tensor and pseudoscalar terms. Current limits on the scalar and tensor coupling constants from neutron and nuclear $\\beta$ decay are on the level of several percent. The goal of this paper is extracting new information on tensor coupling constants by measuring the $\\beta$-asymmetry parameter in the pure Gamow-Teller decay of $^{67}$Cu, thereby testing the V-A structure of the weak interaction. An iron sample foil into which the radioactive nuclei were implanted was cooled down to milliKelvin temperatures in a $^3$He-$^4$He dilution refrigerator. An external magnetic field of 0.1 T, in combination with the internal hyperfine magnetic field, oriented the nuclei. The anisotropic $\\beta$ radiation was observed with planar high purity germanium d...

  17. Coherent production of single pions and ρ mesons in charged-current interactions of neutrinos and antineutrinos on neon nuclei at the Fermilab Tevatron

    Science.gov (United States)

    Willocq, S.; Aderholz, M.; Akbari, H.; Allport, P. P.; Badyal, S. K.; Ballagh, H. C.; Barth, M.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Cence, R. J.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; de Prospo, D.; Devanand; de Wolf, E.; Faulkner, P. J.; Foeth, H.; Fretter, W. B.; Gupta, V. K.; Hanlon, J.; Harigel, G.; Harris, F. A.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Kafka, T.; Kalelkar, M.; Kohli, J. M.; Koller, E. L.; Krawiec, R. J.; Lauko, M.; Lys, J. E.; Marage, P.; Milburn, R. H.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Sacton, J.; Sambyal, S. S.; Schmitz, N.; Schneps, J.; Singh, J. B.; Singh, S.; Smart, W.; Stamer, P.; Varvell, K. E.; Verluyten, L.; Wachsmuth, H.; Wainstein, S.; Yost, G. P.

    1993-04-01

    The coherent production of π and ρ mesons in νμ(ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Teva- tron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53+/-9) μ+/-π-/+ coherent events and (19+/-7) μ+/-π-/+π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2+/-0.7)×10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1+/-0.8)×10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at ||t||<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.

  18. G-parity violation of weak nucleon current and in-medium mass renormalization of nucleons detected through the beta decays of spin aligned sup 1 sup 2 B and sup 1 sup 2 N

    CERN Document Server

    Minamisono, K; Sumikama, T; Nagatomo, T; Matsuta, K; Minamisono, T; Fukuda, M; Koshigiri, K; Morita, M

    2000-01-01

    The beta-ray angular distributions from purely spin aligned sup 1 sup 2 B and sup 1 sup 2 N were precisely measured to determine a new limit of the G-parity irregular induced tensor form factor in weak nucleon axial vector currents and to study the in-medium mass renormalization of nucleons through the axial charge. Since the major systematic error in the previous result which originated from the intensity fluctuation of the incident beam used for the production of the nuclei was removed in the present measurement, the more reliable result was obtained: 0.01 <= 2M f sub T /f sub A <= 0.34 (90 % CL). The result is consistent with the theoretical prediction in the framework of which induced tensor form factor is proportional to the mass difference between the up and down quarks. We also determined the axial charge of the weak nucleon current to be y = 4.66 +- 0.12, which may disclose an in-medium mass reduction of the decaying nucleon of 11 +- 4 %.

  19. Weak currents

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1976-01-01

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

  20. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2012-01-01

    In a new branch of physics and technology called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called 'spin current', are manipulated and controlled together. This book provides an introduction and guide to the new physics and application of spin current.

  1. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  2. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2017-01-01

    Since the discovery of the giant magnetoresistance effect in magnetic multilayers in 1988, a new branch of physics and technology, called spin-electronics or spintronics, has emerged, where the flow of electrical charge as well as the flow of electron spin, the so-called “spin current,” are manipulated and controlled together. The physics of magnetism and the application of spin current have progressed in tandem with the nanofabrication technology of magnets and the engineering of interfaces and thin films. This book aims to provide an introduction and guide to the new physics and applications of spin current, with an emphasis on the interaction between spin and charge currents in magnetic nanostructures.

  3. Neutral currents

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1977-01-01

    It is stated that over the past few years considerable progress has been made in the field of weak interactions. The existence of neutral currents involving leptons and hadrons has been established and some of the questions concerning their detailed structure have been answered. This imposes constraints on the gauge theories and has eliminated large classes of models. New questions have also been raised, one of which concerns the conservation laws obeyed by neutral currents. The wide range of investigations is impressive and is expected to continue with new results from particle, nuclear, and atomic physics. Headings include - various aspects of a gauge theory (choice of group, the symmetry breaking scheme, representation assignments for fermion fields); space-time structure; isospin structure; leptonic neutral currents; and atomic experiments. (U.K.)

  4. Neutral currents

    International Nuclear Information System (INIS)

    Aubert, B.

    1994-11-01

    The evidence for the existence of weak neutral current has been a very controverted topics in the early 1970's, as well as the muon did in the 1930's. The history is very rich considering the evolution of the experimental techniques in high energy particle physics. The history of the discovery and the study of weak neutral current is reviewed. Later the quest of the intermediate vector boson continues with the decision of the community to build a large proton antiproton collider. (K.A.). 14 refs., 1 fig

  5. Current algebra

    International Nuclear Information System (INIS)

    Jacob, M.

    1967-01-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( ΔI = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [fr

  6. Current Titles

    Energy Technology Data Exchange (ETDEWEB)

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  7. Current scenario

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Current scenario. India , like other parts of the world, is also facing the problem of increase in the incidence of drug resistance in tuberculosis. Multi-drug resistance (MDR, resistance to RIF & INH) and extensively drug resistant strains (X-DR, resistance to RIF, INH, FQs ...

  8. Measurement of the β-asymmetry parameter of Cu67 in search for tensor-type currents in the weak interaction

    Science.gov (United States)

    Soti, G.; Wauters, F.; Breitenfeldt, M.; Finlay, P.; Herzog, P.; Knecht, A.; Köster, U.; Kraev, I. S.; Porobic, T.; Prashanth, P. N.; Towner, I. S.; Tramm, C.; Zákoucký, D.; Severijns, N.

    2014-09-01

    Background: Precision measurements at low energy search for physics beyond the standard model in a way complementary to searches for new particles at colliders. In the weak sector the most general β-decay Hamiltonian contains, besides vector and axial-vector terms, also scalar, tensor, and pseudoscalar terms. Current limits on the scalar and tensor coupling constants from neutron and nuclear β decay are on the level of several percent. Purpose: Extracting new information on tensor coupling constants by measuring the β-asymmetry parameter in the pure Gamow-Teller decay of Cu67, thereby testing the V-A structure of the weak interaction. Method: An iron sample foil into which the radioactive nuclei were implanted was cooled down to mK temperatures in a 3He-4He dilution refrigerator. An external magnetic field of 0.1 T, in combination with the internal hyperfine magnetic field, oriented the nuclei. The anisotropic β radiation was observed with planar high-purity germanium detectors operating at a temperature of about 10 K. An on-line measurement of the β asymmetry of Cu68 was performed as well for normalization purposes. Systematic effects were investigated using geant4 simulations. Results: The experimental value, Ã=0.587(14), is in agreement with the standard model value of 0.5991(2) and is interpreted in terms of physics beyond the standard model. The limits obtained on possible tensor-type charged currents in the weak interaction Hamiltonian are -0.045<(CT+CT')/CA<0.159 (90% C.L.). Conclusions: The obtained limits are comparable to limits from other correlation measurements in nuclear β decay and contribute to further constraining tensor coupling constants.

  9. Current awareness.

    Science.gov (United States)

    Compagno, C; Brambilla, L; Capitanio, D; Boschi, F; Ranzi, B M; Porro, D

    2001-05-01

    In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (4 weeks journals - search completed 7th Mar. 2001)

  10. Current titles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Gretchen Hermes at (510) 486-5006 or address below for a User`s Guide. Copies of available papers can be ordered from: Theda Crawford National Center for Electron Microscopy, Lawrence Berkeley Laboratory, One Cyclotron Rd., MS72, Berkeley, California, USA 94720.

  11. Current ornithology

    CERN Document Server

    1983-01-01

    The appearance of the first volume of a projected series is the occasion for comment on scope, aims, and genesis of the work. The scope of Current Ornithology is all of the biology of birds. Ornithology, as a whole-organism science, is concerned with birds at every level of bi­ ological organization, from the molecular to the community, at least from the Jurassic to the present time, and over every scholarly discipline in which bird biology is done; to say this is merely to expand a dic­ tionary definition of "ornithology. " The aim of the work, to be realized over several volumes, is to present reviews or position statements con­ cerning the active fields of ornithological research. The reviews will be relatively short, and often will be done from the viewpoint of a readily­ identified group or school. Such a work could have come into being at any time within the past fifty years, but that Current Ornithology appears now is a result of events that are only seven to eight years old. One important event wa...

  12. More sum rules for quark and lepton masses

    International Nuclear Information System (INIS)

    Terazawa, Hidezumi.

    1990-04-01

    Sum rules for quark and lepton masses are derived from the Ward identity of Chanowitz and Ellis for the vertex function of the trace of the energy-momentum tensor and the two axial-vector currents and the partially conserved axial-vector current hypothesis. They indicate, among other things, that the constituent quark masses of u and d and those of the techniquarks, if any, are about 300 MeV and 300 GeV, respectively. (author)

  13. Weak neutral-current effects in e+e- → μ+μ- at 29 GeV

    International Nuclear Information System (INIS)

    Fernandez, E.; Ford, W.T.; Read, A.L. Jr.

    1983-07-01

    We present a measurement of the cross section for production of collinear muon pairs based upon a sample of more than 10,000 events observed in the MAC detector at PEP. From the asymmetry A/sub μμ = -0.058 +- 0.010 we find the axial vector weak neutral coupling to be given by g/sub A//sup e/g/sub A//sup μ/ = 0.24 +- 0.04

  14. Holographic heat current as Noether current

    Science.gov (United States)

    Liu, Hai-Shan; Lü, H.; Pope, C. N.

    2017-09-01

    We employ the Noether procedure to derive a general formula for the radially conserved heat current in AdS planar black holes with certain transverse and traceless perturbations, for a general class of gravity theories. For Einstein gravity, the general higher-order Lovelock gravities and also a class of Horndeski gravities, we derive the boundary stress tensor and show that the resulting boundary heat current matches precisely the bulk Noether current.

  15. A Study of Charged Current Single Charged Pion Productions on Carbon in a Few-GeV Neutrino Beam

    Energy Technology Data Exchange (ETDEWEB)

    Hiraide, Katsuki [Kyoto Univ. (Japan)

    2009-01-01

    Understanding single charged pion production via neutrino-nucleus charged current interaction in the neutrino energy region of a few GeV is essential for future neutrino oscillation experiments since this process is a dominant background for vμ → vx oscillation measurements. There are two contributions to this process: single pion production via baryonic resonance (vμN → μ-+) and coherent pion production interacting with the entire nucleus (vμA → μ-+), where N is nucleon in the nucleus and A is the nucleus. The purpose of the study presented in this thesis is a precise measurement of charged current single charged pion productions, resonant and coherent pion productions, with a good final state separation in the neutrino energy region of a few GeV. In this thesis, we focus on the study of charged current coherent pion production from muon neutrinos scattering on carbon, vμ 12C → μ-12+, in the SciBooNE experiment. This is motivated by the fact that without measuring this component first, the precise determination of resonant pion production cross section can not be achieved since the contribution of coherent pion production in the region of small muon scattering angle is not small. Furthermore, the coherent process is particularly interesting because it is deeply rooted in fundamental physics via Adler's partially conserved axial-vector current theorem. We took data from June 2007 until August 2008, in both the neutrino and antineutrino beam. In total, 2.52 x 1020 protons on target were collected. We have performed a search for charged current coherent pion production by using SciBooNE's full neutrino data set, corresponding to 0.99 x 1020 protons on target. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio

  16. Current lead thermal analysis code 'CURRENT'

    International Nuclear Information System (INIS)

    Yamaguchi, Masahito; Tada, Eisuke; Shimamoto, Susumu; Hata, Kenichiro.

    1985-08-01

    Large gas-cooled current lead with the capacity more than 30 kA and 22 kV is required for superconducting toroidal and poloidal coils for fusion application. The current lead is used to carry electrical current from the power supply system at room temperature to the superconducting coil at 4 K. Accordingly, the thermal performance of the current lead is significantly important to determine the heat load requirements of the coil system at 4 K. Japan Atomic Energy Research Institute (JAERI) has being developed the large gas-cooled current leads with the optimum condition in which the heat load is around 1 W per 1 kA at 4 K. In order to design the current lead with the optimum thermal performances, JAERI developed thermal analysis code named as ''CURRENT'' which can theoretically calculate the optimum geometric shape and cooling conditions of the current lead. The basic equations and the instruction manual of the analysis code are described in this report. (author)

  17. CMOS current controlled fully balanced current conveyor

    International Nuclear Information System (INIS)

    Wang Chunhua; Zhang Qiujing; Liu Haiguang

    2009-01-01

    This paper presents a current controlled fully balanced second-generation current conveyor circuit (CF-BCCII). The proposed circuit has the traits of fully balanced architecture, and its X-Y terminals are current controllable. Based on the CFBCCII, two biquadratic universal filters are also proposed as its applications. The CFBCCII circuits and the two filters were fabricated with chartered 0.35-μm CMOS technology; with ±1.65 V power supply voltage, the total power consumption of the CFBCCII circuit is 3.6 mW. Comparisons between measured and HSpice simulation results are also given.

  18. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  19. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  20. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  1. Superconformal current multiplet

    International Nuclear Information System (INIS)

    Smailagic, A.

    1982-12-01

    We consider a derivation of a superconformal current multiplet based directly on superconformal algebra. This gives usual multiplet of currents without anomalies, directly in terms of ''improved'' quantities and without reference to a particular Lagrangian model. (author)

  2. Current Research Studies

    Science.gov (United States)

    ... Success Home > Explore Research > Current Research Studies Current Research Studies Email Print + Share The Crohn’s & Colitis Foundation ... conducted online. Learn more about IBD Partners. Clinical Research Alliance The Clinical Research Alliance is a network ...

  3. Currents on Grassmann algebras

    International Nuclear Information System (INIS)

    Coquereaux, R.; Ragoucy, E.

    1993-09-01

    Currents are defined on a Grassmann algebra Gr(N) with N generators as distributions on its exterior algebra (using the symmetric wedge product). The currents are interpreted in terms of Z 2 -graded Hochschild cohomology and closed currents in terms of cyclic cocycles (they are particular multilinear forms on Gr(N)). An explicit construction of the vector space of closed currents of degree p on Gr(N) is given by using Berezin integration. (authors). 10 refs

  4. Eddy current seminar

    International Nuclear Information System (INIS)

    Emson, C.R.I.

    1988-11-01

    The paper presents the fifth symposium in the series of Eddy Current Seminars, held in Abingdon, 1988. The meeting included a discussion on three-dimensional eddy current formulations, as well as thirteen contributed papers on computational electromagnetics. Of the thirteen papers, two papers on eddy currents in tokamaks were selected for INIS and indexed separately. (U.K.)

  5. Fast wave current drive

    International Nuclear Information System (INIS)

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities

  6. Current and Current Fluctuations in Quantum Shuttles

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka; Flindt, Christian; Novotny, Tomas

    2005-01-01

    theoretical tools needed for the analysis, e.g., generalized master equations and Wigner functions, and we outline the methods how the resulting large numerical problems can be handled. Illustrative results are given for current, noise, and full counting statistics for a number of model systems. Throughout...... the review we focus on the physics behind the various approximations, and some simple examples are given to illustrate the theoretical concepts. We also comment on the experimental situation. ©2005 American Institute of Physics...

  7. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  8. Purely leptonic currents

    International Nuclear Information System (INIS)

    Gourdin, M.

    1976-01-01

    In most gauge theories weak neutral currents appear as a natural consequence of the models, but the specific properties are not predicted in a general way. In purely leptonic interactions the structure of these currents can be tested without making assumptions about the weak couplings of the hadrons. The influence of neutral currents appearing in the process e + e - → μ + μ - can be measured using the polarization of the outgoing myons. (BJ) [de

  9. Modulated Current Drive Measurements

    International Nuclear Information System (INIS)

    Petty, C.C.; Lohr, J.; Luce, T.C.; Prater, R.; Cox, W.A.; Forest, C.B.; Jayakumar, R.J.; Makowski, M.A.

    2005-01-01

    A new measurement approach is presented which directly determines the noninductive current profile from the periodic response of the motional Stark effect (MSE) signals to the slow modulation of the external current drive source. A Fourier transform of the poloidal magnetic flux diffusion equation is used to analyze the MSE data. An example of this measurement technique is shown using modulated electron cyclotron current drive (ECCD) discharges from the DIII-D tokamak

  10. Superconducting current generators

    International Nuclear Information System (INIS)

    Genevey, P.

    1970-01-01

    After a brief summary of the principle of energy storage and liberation with superconducting coils,two current generators are described that create currents in the range 600 to 1400 A, used for two storage experiments of 25 kJ and 50 kJ respectively. The two current generators are: a) a flux pump and b) a superconducting transformer. Both could be developed into more powerful units. The study shows the advantage of the transformer over the flux pump in order to create large currents. The efficiencies of the two generators are 95 per cent and 40 to 60 per cent respectively. (author) [fr

  11. Quantization of interface currents

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Motoko [AIMR, Tohoku University, Sendai (Japan); Schulz-Baldes, Hermann [Department Mathematik, Universität Erlangen-Nürnberg, Erlangen (Germany); Villegas-Blas, Carlos [Instituto de Matematicas, Cuernavaca, UNAM, Cuernavaca (Mexico)

    2014-12-15

    At the interface of two two-dimensional quantum systems, there may exist interface currents similar to edge currents in quantum Hall systems. It is proved that these interface currents are macroscopically quantized by an integer that is given by the difference of the Chern numbers of the two systems. It is also argued that at the interface between two time-reversal invariant systems with half-integer spin, one of which is trivial and the other non-trivial, there are dissipationless spin-polarized interface currents.

  12. Current Energy Patents

    International Nuclear Information System (INIS)

    Kelly, R.C.

    1982-01-01

    Current Energy Patents (CEP) provides abstracting and indexing coverage of the international patent literature, including patent applications, that concerns any aspect of energy production, conservation, and utilization

  13. Compton current detector

    International Nuclear Information System (INIS)

    Carvalho Campos, J.S. de.

    1984-01-01

    The project and construction of a Compton current detector, with cylindrical geometry using teflon as dielectric material; for electromagnetic radiation in range energy between 10 KeV and 2 MeV are described. The measurements of Compton current in teflon were obtained using an electrometer. The Compton current was promoted by photon flux proceeding from X ray sources (MG 150 Muller device) and gamma rays of 60 Co. The theory elaborated to explain the experimental results is shown. The calibration curves for accumulated charge and current in detector in function of exposition rates were obtained. (M.C.K.) [pt

  14. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A; Laird, J S; Bardos, R A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T; Sekiguchi, H [Electrotechnical Laboratory, Tsukuba (Japan).

    1994-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  15. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  16. Current organic chemistry

    National Research Council Canada - National Science Library

    1997-01-01

    Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical...

  17. High current ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.

    1989-06-01

    The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be 'high', while in another area a current of 10 Amperes could 'low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper

  18. Turbidity Current Bedforms

    NARCIS (Netherlands)

    Cartigny, Matthieu; Postma, G.

    2017-01-01

    Turbidity currents in the submarine seascape are what river flows are in terrestrial landscapes. While rivers transport sediment from the mountains through valleys towards the sea, turbidity currents transport sediment from the shallow marine realms through canyons towards the deeper abyssal plains.

  19. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  20. Weak mixing below the weak scale in dark-matter direct detection

    Science.gov (United States)

    Brod, Joachim; Grinstein, Benjamin; Stamou, Emmanuel; Zupan, Jure

    2018-02-01

    If dark matter couples predominantly to the axial-vector currents with heavy quarks, the leading contribution to dark-matter scattering on nuclei is either due to one-loop weak corrections or due to the heavy-quark axial charges of the nucleons. We calculate the effects of Higgs and weak gauge-boson exchanges for dark matter coupling to heavy-quark axial-vector currents in an effective theory below the weak scale. By explicit computation, we show that the leading-logarithmic QCD corrections are important, and thus resum them to all orders using the renormalization group.

  1. Cryogenic high current discharges

    International Nuclear Information System (INIS)

    Meierovich, B.E.

    1994-01-01

    Z-pinches formed from frozen deuterium fibers by a rapidly rising current have enhanced stability and high neutron yield. The efforts to understand the enhanced stability and neutron yield on the basis of classical picture of Bennett equilibrium of the current channel has not given satisfactory results. The traditional approach does not take into account the essential difference between the frozen deuterium fiber Z-pinches and the usual Z-pinches such as exploding wires or classical gas-puffed Z-pinches. The very low temperature of the fiber atoms (10 K), together with the rapidly rising current, result in the coexistence of a high current channel with unionized fiber atoms for a substantial period of time. This phenomena lasts during the risetime. This approach takes into account the difference of the breakdown in a dielectric deuterium fiber and the breakdown in a metallic wire. This difference is essential to the understanding of specific features of cryogenic high current discharges. Z-pinches in frozen deuterium fibers should be considered as a qualitatively new phenomenon on the boundary of cryogenic and high current physics. It is a start of a new branch in plasma physics: the physics of cryogenic high current discharges

  2. Current density tensors

    Science.gov (United States)

    Lazzeretti, Paolo

    2018-04-01

    It is shown that nonsymmetric second-rank current density tensors, related to the current densities induced by magnetic fields and nuclear magnetic dipole moments, are fundamental properties of a molecule. Together with magnetizability, nuclear magnetic shielding, and nuclear spin-spin coupling, they completely characterize its response to magnetic perturbations. Gauge invariance, resolution into isotropic, deviatoric, and antisymmetric parts, and contributions of current density tensors to magnetic properties are discussed. The components of the second-rank tensor properties are rationalized via relationships explicitly connecting them to the direction of the induced current density vectors and to the components of the current density tensors. The contribution of the deviatoric part to the average value of magnetizability, nuclear shielding, and nuclear spin-spin coupling, uniquely determined by the antisymmetric part of current density tensors, vanishes identically. The physical meaning of isotropic and anisotropic invariants of current density tensors has been investigated, and the connection between anisotropy magnitude and electron delocalization has been discussed.

  3. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  4. Geothermal Energy: Current abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Ringe, A.C. (ed.)

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  5. Opinions on Current Reading.

    Science.gov (United States)

    Journal of Blacks in Higher Education, 1997

    1997-01-01

    Presents eight reviews of current books, covering issues of particular interest to black educators and historians. Topics considered include slavery, college admissions and affirmative action, the marginalization of black scientists, black politics, bigotry, and higher education. (SLD)

  6. CURRENT TRANSFER SYSTEMS

    Science.gov (United States)

    Watt, D.A.

    1956-07-01

    A current transfer system is described for transferring current between a rotating member and a co-axial stationary member. The particular area of application for the invention is in connection with homopolar generators where a low voltage and high current are generated. The current tramsfer system of the invention comprises a rotor member and a co-axial stator member wherein one of the members is shaped to provide a circumferential surface concave in section and the other member is shaped to have a peripheral portion in close proximity to the surface, whereby a liquid metal can be stably supported between the two members when they are moving relative to one another to establish an electrical conducting path between the members.

  7. Current Resource Imagery Projects

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — Map showing coverage of current Resource imagery projects. High resolution/large scale Resource imagery is typically acquired for the U.S. Forest Service and other...

  8. Current Icing Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Current Icing Product (CIP) is an automatically-generated index suitable for depicting areas of potentially hazardous airframe icing. The CIP algorithm combines...

  9. Medicare Current Beneficiary Survey

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Characteristics and Perceptions of the Medicare Population Data from the 2010 Medicare Current Beneficiary Survey is a series of source books based on the...

  10. Charged weak currents

    International Nuclear Information System (INIS)

    Turlay, R.

    1979-01-01

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

  11. Eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Lee, Hyang Beom; Kim, Young Hwan [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan Univ., Gunsan (Korea, Republic of)

    2004-02-15

    Eddy current testing has been widely used for non destructive testing of steam generator tubes. In order to retain reliability in ECT, the following subjects were carried out in this study: numerical modeling and analysis of defects by using BC and RPC probes in SG tube, preparation of absolute coil impedance plane diagram by FEM. Signal interpretation of the eddy current signals obtained from nuclear power plants.

  12. Eddy current testing

    International Nuclear Information System (INIS)

    Song, Sung Jin; Lee, Hyang Beom; Kim, Young Hwan; Shin, Young Kil

    2004-02-01

    Eddy current testing has been widely used for non destructive testing of steam generator tubes. In order to retain reliability in ECT, the following subjects were carried out in this study: numerical modeling and analysis of defects by using BC and RPC probes in SG tube, preparation of absolute coil impedance plane diagram by FEM. Signal interpretation of the eddy current signals obtained from nuclear power plants

  13. Current Issues in Tourism

    OpenAIRE

    Xu, Shi; Martinez, Larry R.; Hubert, Van Hoof; Tews, Michael; Torres, Leonardo; Farfán, Karina

    2015-01-01

    Ram (2015 Ram, Y. (2015). Hostility or hospitality? A review on violence, bullying and sexual harassment in the tourism and hospitality industry. Current Issues in Tourism. doi:10.1080/13683500.2015.1064364 [Taylor & Francis Online], [Google Scholar] . Hostility or hospitality? A review on violence, bullying and sexual harassment in the tourism and hospitality industry. Current Issues in Tourism. doi:10.1080/13683500.2015.1064364) posits that violence and harassment are areas of concern...

  14. Simple WZW currents

    International Nuclear Information System (INIS)

    Fuchs, J.

    1990-08-01

    A complete classification of simple currents of WZW theory is obtained. The proof is based on an analysis of the quantum dimensions of the primary fields. Simple currents are precisely the primaries with unit quantum dimension; for WZW theories explicit formulae for the quantum dimensions can be derived so that an identification of the fields with unit quantum dimension is possible. (author). 19 refs.; 2 tabs

  15. Current level detector

    International Nuclear Information System (INIS)

    Kerns, C.R.

    1977-01-01

    A device is provided for detecting the current level of a dc signal. It includes an even harmonic modulator to which a reference ac signal is applied. The unknown dc signal acts on the reference ac signal so that the output of the modulator includes an even harmonic whose amplitude is proportional to the unknown dc current. The device may be used to provide overcurrent protection for proportional wire chambers

  16. Induced current heating probe

    International Nuclear Information System (INIS)

    Thatcher, G.; Ferguson, B.G.; Winstanley, J.P.

    1984-01-01

    An induced current heating probe is of thimble form and has an outer conducting sheath and a water flooded flux-generating unit formed from a stack of ferrite rings coaxially disposed in the sheath. The energising coil is made of solid wire which connects at one end with a coaxial water current tube and at the other end with the sheath. The stack of ferrite rings may include non-magnetic insulating rings which help to shape the flux. (author)

  17. Superconducting current transducer

    International Nuclear Information System (INIS)

    Kuchnir, M.; Ozelis, J.P.

    1990-10-01

    The construction and performance of an electric current meter that operates in liquid He and mechanically splits apart to permit replacement of the current carrying conductor is described. It permits the measurement of currents induced in a loop of superconducting cable and expeditious exchange of such loops. It is a key component for a short sample cable testing facility that requires no high current power supplies nor high current leads. Its superconducting pickup circuit involves a non-magnetic core toroidal split-coil that surrounds the conductor and a solenoid whose field is sensed by a Hall probe. This toroidal split-coil is potted inside another compensating toroidal split-coil. The C shaped half toroids can be separated and brought precisely together from outside the cryostat. The Hall probe is energized and sensed by a lock-in amplifier whose output drives a bipolar power supply which feeds the compensating coil. The output is the voltage across a resistor in this feedback circuit. Currents of up to 10 kA can be measured with a precision of 150 mA. 3 refs., 4 figs

  18. Adjustable direct current and pulsed circuit fault current limiter

    Science.gov (United States)

    Boenig, Heinrich J.; Schillig, Josef B.

    2003-09-23

    A fault current limiting system for direct current circuits and for pulsed power circuit. In the circuits, a current source biases a diode that is in series with the circuits' transmission line. If fault current in a circuit exceeds current from the current source biasing the diode open, the diode will cease conducting and route the fault current through the current source and an inductor. This limits the rate of rise and the peak value of the fault current.

  19. Collisionless current sheet equilibria

    Science.gov (United States)

    Neukirch, T.; Wilson, F.; Allanson, O.

    2018-01-01

    Current sheets are important for the structure and dynamics of many plasma systems. In space and astrophysical plasmas they play a crucial role in activity processes, for example by facilitating the release of magnetic energy via processes such as magnetic reconnection. In this contribution we will focus on collisionless plasma systems. A sensible first step in any investigation of physical processes involving current sheets is to find appropriate equilibrium solutions. The theory of collisionless plasma equilibria is well established, but over the past few years there has been a renewed interest in finding equilibrium distribution functions for collisionless current sheets with particular properties, for example for cases where the current density is parallel to the magnetic field (force-free current sheets). This interest is due to a combination of scientific curiosity and potential applications to space and astrophysical plasmas. In this paper we will give an overview of some of the recent developments, discuss their potential applications and address a number of open questions.

  20. Electric current - frequency converter

    International Nuclear Information System (INIS)

    Kumahara, Tadashi; Kinbana, Setsuro.

    1967-01-01

    Herein disclosed is an improved simple electric current-frequency converter, the input current and output frequency linearity of which is widened to a range of four to five figures while compensating, for temperature. The converter may be used for computor processing and for telemetering the output signals from a nuclear reactor. The converter is an astable multivibrator which includes charging circuits comprising emitter-voltage compensated NPN transistors, a charged voltage detecting circuit of temperature compensated field effect transistors, and a transistor switching circuit for generating switching pulses independent of temperature. The converter exhibited a 0.7% frequency change within a range of 5 - 45 0 C and less than a 0.1% frequency drift after six hours of operation when the input current was maintained constant. (Yamaguchi, T.)

  1. Decomposing the Current

    DEFF Research Database (Denmark)

    Hansen, Tim

    The field of molecular electronics have been shown to span a huge range of properties. In an effort to extract the parameters of the system that governs these properties, a number of methods that decomposes the current have been developed. These methods function not just as tools for data...... extraction, but also serves as the foundation upon which to gain insights into the physics that governs the molecular properties. As such, the understanding of the applicability and the development of new methods to decompose the current may be a goal in it self. In this thesis we will explore some...... of these methods, and use the insights from this study to develop new methods. First, we will compare two methods that decompose the current into the transmission from a single conducting level of the molecular device, by extracting level position and broadening. In general we see that the method that relies on I...

  2. Current algebra for parafields

    International Nuclear Information System (INIS)

    Palev, Ch.D.

    1976-01-01

    Within the framework of the Lagrangean QFT a generalization of canonical commutation and anticommutation relations in terms of three-linear commutation relations, corresponding to the parastatistics, s discussed. A detailed derivation of these three-linear relations for a set of parafermi fields is presented. Then for a Lagrangean, depending of a family of parabose fields and a family of paraferm fields, is shown that the fundamental hypothesis of current algebra is valid. In other words, the currents corresponding to the linear gauge transformations are found to meet the commutation relation: [Jsub(f)sup(0)(x), Jsub(g)sup(0)]sub(x 0 =y 0 ) = -idelta(x vector - y vector)Jsub([f,g])sup(0) (x), where Jsub(f)sup(0) is a time component of the current, corresponding to transformation f. (S.P.)

  3. Fault current limiter

    Science.gov (United States)

    Darmann, Francis Anthony

    2013-10-08

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  4. Dispersive approach to the axial anomaly and nonrenormalization theorem

    International Nuclear Information System (INIS)

    Pasechnik, R.S.; Teryaev, O.V.

    2006-01-01

    Anomalous triangle graphs for the divergence of the axial-vector current are studied using the dispersive approach generalized for the case of higher orders of perturbation theory. The validity of this procedure is proved up to the two-loop level. By direct calculation in the framework of dispersive approach we have obtained that the two-loop axial-vector-vector (AVV) amplitude is equal to zero. According to the Vainshtein's theorem, the transversal part of the anomalous triangle is not renormalized in the chiral limit. We generalize this theorem for the case of finite fermion mass in the triangle loop

  5. Second class weak currents

    International Nuclear Information System (INIS)

    Delorme, J.

    1978-01-01

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

  6. Issues in neutral currents

    International Nuclear Information System (INIS)

    Sehgal, L.M.

    1980-01-01

    The experimental results on low energy confirming the structure of the effective Lagrangian of the weak neutral current processes as predicted by the Salam-Weinberg model are reviewed. Some possible modifications of the effective Lagrangian and the feasibility of their experimental verification are also considered. (P.L.)

  7. High current induction linacs

    International Nuclear Information System (INIS)

    Barletta, W.; Faltens, A.; Henestroza, E.; Lee, E.

    1994-07-01

    Induction linacs are among the most powerful accelerators in existence. They have accelerated electron bunches of several kiloamperes, and are being investigated as drivers for heavy ion driven inertial confinement fusion (HIF), which requires peak beam currents of kiloamperes and average beam powers of some tens of megawatts. The requirement for waste transmutation with an 800 MeV proton or deuteron beam with an average current of 50 mA and an average power of 40 MW lies midway between the electron machines and the heavy ion machines in overall difficulty. Much of the technology and understanding of beam physics carries over from the previous machines to the new requirements. The induction linac allows use of a very large beam aperture, which may turn out to be crucial to reducing beam loss and machine activation from the beam halo. The major issues addressed here are transport of high intensity beams, availability of sources, efficiency of acceleration, and the state of the needed technology for the waste treatment application. Because of the transformer-like action of an induction core and the accompanying magnetizing current, induction linacs make the most economic sense and have the highest efficiencies with large beam currents. Based on present understanding of beam transport limits, induction core magnetizing current requirements, and pulse modulators, the efficiencies could be very high. The study of beam transport at high intensities has been the major activity of the HIF community. Beam transport and sources are limiting at low energies but are not significant constraints at the higher energies. As will be shown, the proton beams will be space-charge-dominated, for which the emittance has only a minor effect on the overall beam diameter but does determine the density falloff at the beam edge

  8. Heavy quark form factors at two loops in perturbative QCD

    International Nuclear Information System (INIS)

    Ablinger, J.; Schneider, C.; Behring, A.; Falcioni, G.

    2017-11-01

    We present the results for heavy quark form factors at two-loop order in perturbative QCD for different currents, namely vector, axial-vector, scalar and pseudo-scalar currents, up to second order in the dimensional regularization parameter. We outline the necessary computational details, ultraviolet renormalization and corresponding universal infrared structure.

  9. Pion-pair production by two photons

    International Nuclear Information System (INIS)

    Terazawa, Hidezumi.

    1994-07-01

    The cross section for pion-pair production by two photons is calculated approximately by using the low energy theorem previously derived from partially-conserved-axial-vector-current hypothesis and current algebra, and found to agree very well with the experimental data recently obtained by the Mark II, TPC/Two-Gamma and CLEO Collaborations. (author)

  10. Heavy quark form factors at two loops in perturbative QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Behring, A. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie; Bluemlein, J.; Freitas, A. de; Marquard, P.; Rana, N. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Falcioni, G. [Nikhef, Amsterdam (Netherlands). Theory Group

    2017-11-15

    We present the results for heavy quark form factors at two-loop order in perturbative QCD for different currents, namely vector, axial-vector, scalar and pseudo-scalar currents, up to second order in the dimensional regularization parameter. We outline the necessary computational details, ultraviolet renormalization and corresponding universal infrared structure.

  11. [Currently available skin substitutes].

    Science.gov (United States)

    Oravcová, Darina; Koller, Ján

    2014-01-01

    The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. Autologous split or full-thickness skin graft are the best definitive burn wound coverage, but it is constrained by the limited available sources, especially in major burns. Donor site morbidities in term of additional wounds and scarring are also of concern of the autograft application. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. This paper reviews currently available skin substitutes, produced in not for-profit skin banks as well as commercially available. They are divided according to type of material included, as biological, biosynthetic and synthetic and named respectively.

  12. Marijuana: Current concepts

    Directory of Open Access Journals (Sweden)

    Donald eGreydanus

    2013-10-01

    Full Text Available Marijuana (cannabis remains a controversial drug in the 21st century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the 21st century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public often confused by a media-driven, though false message and promise of benign pot consumption.

  13. Marijuana: Current Concepts†

    Science.gov (United States)

    Greydanus, Donald E.; Hawver, Elizabeth K.; Greydanus, Megan M.; Merrick, Joav

    2013-01-01

    Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption. PMID:24350211

  14. Current standardisation for nanotechnology

    International Nuclear Information System (INIS)

    Bard, Delphine; Mark, David; Moehlmann, Carsten

    2009-01-01

    Standardisation and standards provide an important mechanism to support both innovation and the application of regulations. There is currently no specific regulation for any nanomaterials. Health, safety and environmental protection aspects associated with nanomaterials are however in principle covered to different levels by current EU regulatory framework. There are a number of national, European and international organisations developing standards associated with the development, description and use of nanomaterials as well as the protection of human health and the environment from the production and use of chemicals and consumer products, including nanomaterials. These organisations have also established specific committees on nanotechnology. This paper outlines the different relevant regulations and standards. This paper will mainly be focused on a European health and safety perspective.

  15. Lead toxicity: current concerns.

    OpenAIRE

    Goyer, R A

    1993-01-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has be...

  16. Marijuana: Current Concepts†

    OpenAIRE

    Greydanus, Donald E.; Hawver, Elizabeth K.; Greydanus, Megan M.; Merrick, Joav

    2013-01-01

    Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mai...

  17. Current driven wiggler

    Science.gov (United States)

    Tournes, C.; Aucouturier, J.; Arnaud, B.; Brasile, J. P.; Convert, G.; Simon, M.

    1992-07-01

    A current-driven wiggler is the cornerstone of an innovative, compact, high-efficiency, transportable tunable free-electron laser (FEL), the feasibility of which is currently being evaluated by Thomson-CSF. The salient advantages are: compactness of the FEL, along with the possibility to accelerate the beam through several successive passes through the accelerating section (the number of passes being defined by the final wavelength of the radiation; i.e. visible, MWIR, LWIR); the wiggler can be turned off and be transparent to the beam until the last pass. Wiggler periodicities as small as 5 mm can be achieved, hence contributing to FEL compactness. To achieve overall efficiencies in the range of 10% at visible wavelengths, not only the wiggler periodicity must be variable, but the strength of the magnetic field of each period can be adjusted separately and fine-tuned versus time during the macropulse, so as to take into account the growing contribution of the wave energy in the cavity to the total ponderomotive force. The salient theoretical point of this design is the optimization of the parameters defining each period of the wiggler for each micropacket of the macropulse. The salient technology point is the mechanical and thermal design of the wiggler which allows the required high currents to achieve magnetic fields up to 2T.

  18. Current issues in onychomycosis.

    Science.gov (United States)

    Trépanier, E F; Amsden, G W

    1998-02-01

    To review the epidemiology, mycology, clinical features and diagnosis, current pharmacotherapy, and pharmacoeconomics of onychomycosis. We conducted a MEDLINE search from 1966 to May 1997. References from these articles, manufacturers of the discussed antimycotics, and relevant abstracts from recent dermatology conferences were used to collect pertinent data. Data were obtained from published controlled studies and case reports. In the pharmacotherapy section, the most weight was placed on fully reported, randomized, controlled comparative trials, but abstracts and case series were included when well-controlled studies were unavailable. Onychomycosis is a common nail disorder that has a substantial impact on patients' quality of life. It is most commonly caused by dermatophytes, but yeasts and molds can also be involved. Diagnosis is made through clinical presentation, potassium hydroxide preparations, and culture of tissue/nail samples. Griseofulvin was the drug of choice for many years, but its low cure rates and the development of newer, more effective drugs made it fall out of favor. Current therapeutic alternatives include fluconazole, itraconazole, and terbinafine. Data on the use of fluconazole are limited to case series and reports. Continuous dosing of itraconazole and terbinafine are well-proven therapies. New data are becoming available on the use of pulse itraconazole dosing, which has recently been approved by the Food and Drug Administration for fingernail infections. These drugs are well tolerated, but attention to drug interactions is necessary with the azoles. Currently, continuous terbinafine appears to be the most cost-effective drug for dermatophyte onychomycosis.

  19. Clopidogrel Resistance: Current Issues

    Directory of Open Access Journals (Sweden)

    NS Neki

    2016-05-01

    Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

  20. Turbidity Current Head Mixing

    Science.gov (United States)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  1. Bremsstrahlung and neutral currents

    International Nuclear Information System (INIS)

    Ellis, R.G.; McKellar, B.H.J.

    1979-01-01

    The utility of the bremsstrahlung process in detecting parity violations from V-A weak neutral current interference is analysed in two ways. Firstly, bremsstrahlung from polarized lepton-nucleus scattering has an asymmetry with respect to the polarization of the incident leptons, and secondly, bremsstrahlung from unpolarized lepton nucleus scattering has a small circular polarization. The magnitude of each effect is calculated. The ratio of the parity violating contribution and the parity conserving contribution to the cross section is shown to be a misleading measure of the utility of these experiments. A parameter, the figure of merit, is introduced and used to discuss the feasibility of possible experiments

  2. Teleradiology - current status

    International Nuclear Information System (INIS)

    Baltadjiev, D.; Charakchiev

    2000-01-01

    Tele-radiology is a term becoming increasingly popular in the medical literature. Nevertheless, terminological definitions in this particular field are still rather vague. The scope of applications extend from simple image presenting via analogue telephone lines to transmission of 3-D medical images through a satellite. It is a matter of standards highly differing in terms of data transmission rates, safety, technical demands on the systems and the like. In this article new information technologies, technical aspects, as well as some major applications of tele-radiology are discussed. The current status of tele-medicine/tele-radiology in this country is likewise briefly outlined

  3. Current awareness on yeast.

    Science.gov (United States)

    2002-02-01

    In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (3 weeks journals - search completed 5th. Dec. 2001)

  4. Low Current Magnet

    Science.gov (United States)

    1992-01-01

    Because Goddard Space Flight Center needed a way to cool sensors aboard the AXAF, a low current superconducting magnet was developed under contract by Cryomagnetics, Inc. The magnet, now commercially available, reduced the rate of helium consumption, extending the lifetime of the AXAF's x-ray spectrometer. On Earth, it offers a way to reduce operating costs through smaller, less expensive power supplies and reduced use of coolant. The magnet has particular advantages for MRI systems, as it is safer and has lower maintenance requirements.

  5. Andropause: Current concepts

    Directory of Open Access Journals (Sweden)

    Parminder Singh

    2013-01-01

    Full Text Available Andropause or late-onset hypogonadism is a common disorder which increases in prevalence with advancing age. Diagnosis of late-onset of hypogonadism is based on presence of symptoms suggestive of testosterone deficiency - prominent among them are sexual symptoms like loss of libido, morning penile erection and erectile dysfunction; and demonstration of low testosterone levels. Adequate therapeutic modalities are currently available, but disparate results of clinical trial suggest further evaluation of complex interaction between androgen deficiency and ageing. Before initiating therapy benefits and risk should be discussed with patients and in case of poor response , alternative cause should be investigated.

  6. Intrinsic superspin Hall current

    Science.gov (United States)

    Linder, Jacob; Amundsen, Morten; Risinggârd, Vetle

    2017-09-01

    We discover an intrinsic superspin Hall current: an injected charge supercurrent in a Josephson junction containing heavy normal metals and a ferromagnet generates a transverse spin supercurrent. There is no accompanying dissipation of energy, in contrast to the conventional spin Hall effect. The physical origin of the effect is an antisymmetric spin density induced among transverse modes ky near the interface of the superconductor arising due to the coexistence of p -wave and conventional s -wave superconducting correlations with a belonging phase mismatch. Our predictions can be tested in hybrid structures including thin heavy metal layers combined with strong ferromagnets and ordinary s -wave superconductors.

  7. Current Ebola vaccines

    Science.gov (United States)

    Hoenen, Thomas; Groseth, Allison; Feldmann, Heinz

    2012-01-01

    Introduction Ebolaviruses cause severe viral hemorrhagic fever in humans and non-human primates, with case fatality rates of up to 90%. Currently, neither a specific treatment nor a vaccine licensed for use in humans is available. However, a number of vaccine candidates have been developed in the last decade that are highly protective in non-human primates, the gold standard animal model for Ebola hemorrhagic fever. Areas covered This review analyzes a number of scenarios for the use of ebolavirus vaccines, discusses the requirements for ebolavirus vaccines in these scenarios, and describes current ebolavirus vaccines. Among these vaccines are recombinant Adenoviruses, recombinant Vesicular Stomatitis viruses, recombinant Human Parainfluenza viruses and virus-like particles. Interestingly, one of these vaccine platforms, based on recombinant Vesicular Stomatitis viruses, has also demonstrated post-exposure protection in non-human primates. Expert opinion The most pressing remaining challenge is now to move these vaccine candidates forward into human trials and towards licensure. In order to achieve this, it will be necessary to establish the mechanisms and correlates of protection for these vaccines, and to continue to demonstrate their safety, particularly in potentially immunocompromised populations. However, already now there is sufficient evidence that, from a scientific perspective, a vaccine protective against ebolaviruses is possible. PMID:22559078

  8. Swine brucellosis: current perspectives

    Directory of Open Access Journals (Sweden)

    Olsen SC

    2016-12-01

    Full Text Available SC Olsen, FM Tatum Infectious Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA Abstract: Brucella suis is a significant zoonotic species that is present in domestic livestock and wildlife in many countries worldwide. Transmission from animal reservoirs is the source of human infection as human-to-human transmission is very rare. Although swine brucellosis causes economic losses in domestic livestock, preventing human infection is the primary reason for its emphasis in disease control programs. Although disease prevalence varies worldwide, in areas outside of Europe, swine brucellosis is predominantly caused by B. suis biovars 1 and 3. In Europe, swine are predominantly infected with biovar 2 which is much less pathogenic in humans. In many areas worldwide, feral or wild populations of swine are important reservoir hosts. Like other Brucella spp. in their natural host, B. suis has developed mechanisms to survive in an intracellular environment and evade immune detection. Limitations in sensitivity and specificity of current diagnostics require use at a herd level, rather for individual animals. There is currently no commercial vaccine approved for preventing brucellosis in swine. Although not feasible in all situations, whole-herd depopulation is the most effective regulatory mechanism to control swine brucellosis. Keywords: livestock, transmission, pathogenicity, vaccine, host, infection

  9. Dispersion and current measurements

    International Nuclear Information System (INIS)

    Boelskifte, S.

    1986-04-01

    A model for the simulation of particle movements in water should incorporate the mutual distance dependent correlation. As long as reliable data are given accessible a model can be created of the dispersion in a given area from a statistical description of turbulence. Current measurements have been performed in an area north of the Swedish nuclear power plant Barsebaeck, and statistical time series analysis have made it possible to estimate multivariate autoregressive moving-average (ARMA) models for these data using the Box-Jenkins method. The correlation structure for the area has been investigated in detail. Transport and dispersion models for the marine environment are used in estimating doses to the population from the aquatic food chain. Some of these models are described with special emphasis on the time and length scales they cover. Furthermore, to illustrate the background of the simulation model, short introductuions are given to health physics, time series analysis, and turbulence theory. Analysis of the simulation model shows the relative importance of the different parameters. The model can be expanded to conditional simulation, where the current measurements are used directly to simulate the movement of one of the particles. Results from the model are also compared to results from a sampling of bioindicators (Fucus vesiculosus) along the Danish coast. The reliability of bioindicators in this kind of experiment is discussed. (author)

  10. Influence of Current Transformer Saturation on Operation of Current Protection

    Directory of Open Access Journals (Sweden)

    F. A. Romaniouk

    2010-01-01

    Full Text Available An analysis of the influence of instrument current transformer errors on operation of current protection of power supply diagram elements has been carried out in the paper. The paper shows the influence of an aperiodic component of transient current and secondary load on current  transformer errors.Peculiar operational features of measuring elements of electromechanical and microprocessor current protection with their joint operation with electromagnetic current transformers have been analyzed in the paper.

  11. On Hall current fluid

    International Nuclear Information System (INIS)

    Shen, M.C.; Ebel, D.

    1987-01-01

    In this paper some new results concerning magnetohydrodynamic (MHD) equations with the Hall current (HC) term in the Ohm's law are presented. For the cylindrical pinch of a compressible HC fluid, it is found that for large time and long wave length the solution to the governing equations exhibits the behavior of solitons as in the case of an ideal MHD model. In some special cases, the HC model appears to be better posed. An open question is whether a simple toroidal equilibrium of an HC fluid with resistivity and viscosity exists. The answer to this question is affirmative if the prescribed velocity on the boundary has a small norm. Furthermore, the equilibrium is also linearly and nonlinearly stable

  12. Pulsed current generator

    International Nuclear Information System (INIS)

    Semenov, V.D.; Furman, Eh.G.

    1974-01-01

    The paper describes a current pulse generator with an auxiliary network consisting of a choke and diode in series designed to enlarge the range of pulse frequency control. One output of the network is connected to an adjustable valve cathode and via antoher auxiliary condenser to the point where the cathode of the main key unit is joined to the start of the magnetizing coil. A second output is connected to the anode of another adjustable valve and via another auxiliary condenser to the point where the anode of the other main key unit is joined to the end of the magnetizing coil. The generator can be used to excite the electromagnets of charged particle accelerators or in devices designed to produce magnetic fields. (author)

  13. Brain abscess: Current management

    Directory of Open Access Journals (Sweden)

    Hernando Alvis-Miranda

    2013-01-01

    Full Text Available Brain abscess (BA is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA.

  14. Fluctuation Relations for Currents

    Science.gov (United States)

    Sinitsyn, Nikolai; Akimov, Alexei; Chernyak, Vladimir; Chertkov, Michael

    2011-03-01

    We consider a non-equilibrium statistical system on a graph or a network. Identical particles are injected, interact with each other, traverse, and leave the graph in a stochastic manner described in terms of Poisson rates, possibly strongly dependent on time and instantaneous occupation numbers at the nodes of the graph. We show that the system demonstrates a profound statistical symmetry, leading to new Fluctuation Relations that originate from the supersymmetry and the principle of the geometric universality of currents rather than from the relations between probabilities of forward and reverse trajectories. NSF/ECCS-0925618, NSF/CHE-0808910 and DOE at LANL under Contract No. DE-AC52-06NA25396.

  15. Necrotizing enterocolitis: current perspectives

    Directory of Open Access Journals (Sweden)

    Yajamanyam PK

    2014-03-01

    Full Text Available Phani Kiran Yajamanyam,1 Shree Vishna Rasiah,1 Andrew K Ewer1,2 1Neonatal Unit, Birmingham Women's Hospital NHS Foundation Trust, 2School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK Abstract: Necrotizing enterocolitis is the most common gastrointestinal emergency in neonates, particularly in those born very preterm. It is a leading cause of morbidity and mortality, especially in extremely low birth weight infants. Despite extensive research, the pathophysiology of necrotizing enterocolitis remains unclear and therapeutic options are limited. Multiple risk factors have been reported, but most are associated with prematurity and its complications. This makes management very challenging in vulnerable preterm infants. In this review, we focus on the risk factors and some of the current research in this area, particularly studies aimed at early detection and potential preventive measures for this potentially lethal condition. Keywords: necrotizing enterocolitis, preterm infants, prematurity, probiotics

  16. Transgender youth: current concepts

    Science.gov (United States)

    2016-01-01

    In many countries throughout the world, increasing numbers of gender nonconforming/transgender youth are seeking medical services to enable the development of physical characteristics consistent with their experienced gender. Such medical services include use of agents to block endogenous puberty at Tanner stage II with subsequent use of cross-sex hormones, and are based on longitudinal studies demonstrating that those individuals who were first identified as gender dysphoric in early or middle childhood and continue to meet the mental health criteria for being transgender at early puberty are likely to be transgender as adults. This review addresses terms and definitions applicable to gender nonconforming youth, studies that shed light on the biologic determinants of gender identity, current clinical practice guidelines for transgender youth, challenges to optimal care, and priorities for research. PMID:28164070

  17. Uterine sarcoma - current perspectives.

    Science.gov (United States)

    Benson, Charlotte; Miah, Aisha B

    2017-01-01

    Uterine sarcomas comprise a group of rare tumors with differing tumor biology, natural history and response to treatment. Diagnosis is often made following surgery for presumed benign disease. Currently, preoperative imaging does not reliably distinguish between benign leiomyomas and other malignant pathology. Uterine leiomyosarcoma is the most common sarcoma, but other subtypes include endometrial stromal sarcoma (low grade and high grade), undifferentiated uterine sarcoma and adenosarcoma. Clinical trials have shown no definite survival benefit of adjuvant radiotherapy or chemotherapy and have been hampered by the rarity and heterogeneity of these disease types. There is a role of adjuvant treatment in carefully selected cases following multidisciplinary discussion at sarcoma reference centers. In patients with metastatic disease, systemic chemotherapy can then be considered. There is activity of a number of agents, including doxorubicin, trabectedin, gemcitabine-based chemotherapy, eribulin and pazopanib. Patients should be considered for clinical trial entry where possible. Close international collaboration is important to allow progress in this group of diseases.

  18. Intracranial atherosclerosis: current concepts.

    Science.gov (United States)

    Arenillas, Juan F

    2011-01-01

    The most relevant ideas discussed in this article are described here. Intracranial atherosclerotic disease (ICAD) represents the most common cause of ischemic stroke worldwide. Its importance in whites may have been underestimated. New technical developments, such as high-resolution MRI, allow direct assessment of the intracranial atherosclerotic plaque, which may have a profound impact on ICAD diagnosis and therapy in the near future. Early detection of ICAD may allow therapeutic intervention while the disease is still asymptomatic. The Barcelonès Nord and Maresme Asymptomatic Intracranial Atherosclerosis Study is presented here. The main prognostic factors that characterize the patients who are at a higher risk for ICAD recurrence are classified and discussed. The best treatment for ICAD remains to be established. The Stenting Versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Study is currently ongoing to address this crucial issue. These and other topics will be discussed at the Fifth International Intracranial Atherosclerosis Conference (Valladolid, Spain, autumn 2011).

  19. Football injuries: current concepts.

    Science.gov (United States)

    Olson, David E; Sikka, Robby Singh; Hamilton, Abigail; Krohn, Austin

    2011-01-01

    Football is one of the most popular sports in the United States and is the leading cause of sports-related injury. A large focus in recent years has been on concussions, sudden cardiac death, and heat illness, all thought to be largely preventable health issues in the young athlete. Injury prevention through better understanding of injury mechanisms, education, proper equipment, and practice techniques and preseason screening may aid in reducing the number of injuries. Proper management of on-field injuries and health emergencies can reduce the morbidity associated with these injuries and may lead to faster return to play and reduced risk of future injury. This article reviews current concepts surrounding frequently seen football-related injuries.

  20. Current issues in asteroseismology

    Energy Technology Data Exchange (ETDEWEB)

    Bazot, Michael; Monteiro, Mario J P F G; Straka, Christian W [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2008-10-15

    In this contribution we briefly review some of the current issues and promises for the future by asteroseismology. We are entering a new phase in this field driven by the wealth of data that has been collected and data that will soon be available for asteroseismology across the HR Diagram. Major difficulties in the descriptions of stellar interiors that arose in the second half of the 20th century may now be in part addressed and solved (this is the expectation{exclamation_point}) by asteroseismology with unprecedented precision. In this contribution we list some of the key open questions in stellar physics, the seismic data we expect to collect in the near future, and some techniques that will provide the tools to connect data and models.

  1. Current Extensions on PULSE

    Directory of Open Access Journals (Sweden)

    Sanda Dragos

    2010-09-01

    Full Text Available Using a learning management system (LMS is a common practise nowadays. Such instruments are used in educational institutions to enhance and support the teaching act as well as in industry for training purposes. In a computer science department of an university such instrument tends to be a basic requirement. That is because not only it allows a better management of courses and a better communication between students and professors, but can also serve as a perfect instrument for presenting teaching related materials for computer science subjects. During the years I have created and used several such instruments: a System with Interactive ackNowledgement and Evaluation of students work during laboratory sessions (SINE, a Php Utility used in Laboratories for Student Evaluation (PULSE, and PULSE Extended. The aim of this paper is to present the current enhancements of PULSE.

  2. COHERENT Experiment: current status

    International Nuclear Information System (INIS)

    Akimov, D; Belov, V; Bolozdynya, A; Burenkov, A; Albert, J B; Del Valle Coello, M; D’Onofrio, M; Awe, C; Barbeau, P S; Cervantes, M; Becker, B; Cabrera-Palmer, B; Collar, J I; Cooper, R J; Cooper, R L; Cuesta, C; Detwiler, J; Eberhardt, A; Dean, D; Dolgolenko, A G

    2017-01-01

    The COHERENT Collaboration is realizing a long term neutrino physics research program. The main goals of the program are to detect and study elastic neutrino-nucleus scattering (CEνNS). This process is predicted by Standard Model but it has never been observed experimentally because of the very low energy of the recoil nucleus. COHERENT is using different detector technologies: CsI[Na] and NaI scintillator crystals, a single-phase liquid Ar and a Ge detectors. The placement of all the detector setups is in the basement of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The current status of the COHERENT experimental program is presented. (paper)

  3. Engineered barriers: current status

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.P.

    1988-01-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  4. Transgender youth: current concepts

    Directory of Open Access Journals (Sweden)

    Stephen M. Rosenthal

    2016-12-01

    Full Text Available In many countries throughout the world, increasing numbers of gender nonconforming/transgender youth are seeking medical services to enable the development of physical characteristics consistent with their experienced gender. Such medical services include use of agents to block endogenous puberty at Tanner stage II with subsequent use of cross-sex hormones, and are based on longitudinal studies demonstrating that those individuals who were first identified as gender dysphoric in early or middle childhood and continue to meet the mental health criteria for being transgender at early puberty are likely to be transgender as adults. This review addresses terms and definitions applicable to gender nonconforming youth, studies that shed light on the biologic determinants of gender identity, current clinical practice guidelines for transgender youth, challenges to optimal care, and priorities for research.

  5. Acquired hypofibrinogenemia: current perspectives

    Directory of Open Access Journals (Sweden)

    Besser MW

    2016-09-01

    Full Text Available Martin W Besser,1 Stephen G MacDonald2 1Department of Haematology, 2Department of Specialist Haemostasis, The Pathology Partnership, Addenbrooke’s Hospital, Cambridge, UK Abstract: Acquired hypofibrinogenemia is most frequently caused by hemodilution and consumption of clotting factors. The aggressive replacement of fibrinogen has become one of the core principles of modern management of massive hemorrhage. The best method for determining the patient’s fibrinogen level remains controversial, and particularly in acquired dysfibrinogenemia, could have major therapeutic implications depending on which quantification method is chosen. This review introduces the available laboratory and point-of-care methods and discusses the relative advantages and limitations. It also discusses current strategies for the correction of hypofibrinogenemia. Keywords: Clauss fibrinogen assay, fibrinogen antigen, viscoelastic testing, ­gravimetric fibrinogen assay, PT-derived fibrinogen, functional fibrinogen, direct oral anticoagulant, dysfibrinogenemia, afibrinogenemia

  6. Misophonia: current perspectives

    Directory of Open Access Journals (Sweden)

    Cavanna AE

    2015-08-01

    Full Text Available Andrea E Cavanna,1–3 Stefano Seri3,4 1Department of Neuropsychiatry, Birmingham and Solihull Mental Health NHS Foundation Trust and University of Birmingham, Birmingham, 2Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, 3School of Life and Health Sciences, Aston Brain Centre, Wellcome Trust Laboratory for MEG Studies, Aston University, 4Children’s Epilepsy Surgery Programme, The Birmingham Children’s Hospital NHS Foundation Trust, Birmingham, UK Abstract: Misophonia is characterized by a negative reaction to a sound with a specific pattern and meaning to a given individual. In this paper, we review the clinical features of this relatively common yet underinvestigated condition, with focus on co-occurring neurodevelopmental disorders. Currently available data on the putative pathophysiology of the condition can inform our understanding and guide the diagnostic process and treatment approach. Tinnitus retraining therapy and cognitive behavior therapy have been proposed as the most effective treatment strategies for reducing symptoms; however, current treatment algorithms should be validated in large population studies. At the present stage, competing paradigms see misophonia as a physiological state potentially inducible in any subject, an idiopathic condition (which can present with comorbid psychiatric disorders, or a symptomatic manifestation of an underlying psychiatric disorder. Agreement on the use of standardized diagnostic criteria would be an important step forward in terms of both clinical practice and scientific inquiry. Areas for future research include phenomenology, epidemiology, modulating factors, neurophysiological underpinnings, and treatment trials. Keywords: misophonia, selective sound sensitivity syndrome, hyperacusis, neurodevelopmental disorders, Tourette syndrome, obsessive-compulsive spectrum

  7. Ocular tuberculosis: current perspectives

    Directory of Open Access Journals (Sweden)

    Shakarchi FI

    2015-11-01

    Full Text Available Faiz I Shakarchi1,21Ibn Al-Haetham Teaching Eye Hospital, 2Department of Opthalmology, Medical College, Al-Mustansiriya University, Baghdad, IraqAbstract: The World Health Organization currently estimates that nearly two billion people, or one-third of the world’s population, are infected by tuberculosis, and that roughly 10% of the infected people are symptomatic. Tuberculosis affects the lungs in 80% of patients, while in the remaining 20% the disease may affect other organs, including the eye. Uveitis can be seen concurrently with tuberculosis, but a direct association is difficult to prove. Ocular tuberculosis is usually not associated with clinical evidence of pulmonary tuberculosis, as up to 60% of extrapulmonary tuberculosis patients may not have pulmonary disease. The diagnosis of tuberculous uveitis is often problematic and in nearly all reported cases, the diagnosis was only presumptive. Tuberculous uveitis is a great mimicker of various uveitis entities and it can be considered in the differential diagnosis of any type of intraocular inflammation. It is still unknown if ocular manifestations result from a direct mycobacterium infection or hypersensitivity reaction and this is reflected on the management of tuberculous uveitis. Prevalence of tuberculosis as an etiology of uveitis may reach up to 10% in endemic areas. Tuberculous uveitis is a vision-threatening disease that inevitably leads to blindness if not properly diagnosed and treated. The aim of this review is to illustrate the various clinical features and management of presumed tuberculous uveitis. The current review focuses on the diagnostic criteria, significance of tuberculin skin test, and use of systemic corticosteroids in the management of tuberculous uveitis as recommended in recent publications.Keywords: tuberculosis, uveitis, choroiditis, tuberculin skin test

  8. The heavy quark form factors at two loops

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Behring, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie; Bluemlein, J.; Freitas, A. de; Marquard, P.; Rana, N. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Falcioni, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Nikhef, Amsterdam (Netherlands). Theory Group

    2017-12-15

    We compute the two-loop QCD corrections to the heavy quark form factors in case of the vector, axial-vector, scalar and pseudo-scalar currents up to second order in the dimensional parameter ε=(4-D)/2. These terms are required in the renormalization of the higher order corrections to these form factors.

  9. An overview of lattice QCD

    International Nuclear Information System (INIS)

    Woloshyn, R.M.

    1988-03-01

    The basic concepts of the Lagrangian formulation of lattice field theory are discussed. The Wilson and staggered schemes for dealing with fermions on the lattice are described. Some recent results for hadron masses and vector and axial vector current matrix elements in lattice QCD are reviewed. (Author) (118 refs., 16 figs.)

  10. Stochastic quantization for the axial model

    International Nuclear Information System (INIS)

    Farina, C.; Montani, H.; Albuquerque, L.C.

    1991-01-01

    We use bosonization ideas to solve the axial model in the stochastic quantization framework. We obtain the fermion propagator of the theory decoupling directly the Langevin equation, instead of the Fokker-Planck equation. In the Appendix we calculate explicitly the anomalous divergence of the axial-vector current by using a regularization that does not break the Markovian character of the stochastic process

  11. Adler zero and the dual multiperipheral model

    International Nuclear Information System (INIS)

    Balazs, L.A.P.

    1978-01-01

    We show that the ππ → ππ Adler PCAC (partial conservation of axial-vector current) condition requires a Reggeon intercept α (0) approx. = 0.5 within a broad class of multiperipheral models at the planar and cylinder levels. In the planar approximation this is closely related to the cancellation of the Reggeon-Reggeon cut

  12. The electroweak interaction in e+e- annihilations

    International Nuclear Information System (INIS)

    Marshall, R.

    1982-04-01

    The role of e + e - annihilation in studying the weak neutral current, at PETRA and PEP, is reviewed. The way in which the vector and axial vector couplings appear in the total cross sections, the angular distributions and the polarisation dependences are discussed. The dependence of external gauge models on the results of PETRA and PEP experiments is examined. (U.K.)

  13. Adjustment disorder: current perspectives

    Directory of Open Access Journals (Sweden)

    Zelviene P

    2018-01-01

    Full Text Available Paulina Zelviene, Evaldas Kazlauskas Department of Clinical and Organizational Psychology, Vilnius University, Vilnius, Lithuania Abstract: Adjustment disorder (AjD is among the most often diagnosed mental disorders in clinical practice. This paper reviews current status of AjD research and discusses scientific and clinical issues associated with AjD. AjD has been included in diagnostic classifications for over 50 years. Still, the diagnostic criteria for AjD remain vague and cause difficulties to mental health professionals. Controversies in definition resulted in the lack of reliable and valid measures of AjD. Epidemiological data on prevalence of AjD is scarce and not reliable because prevalence data are biased by the diagnostic algorithm, which is usually developed for each study, as no established diagnostic standards for AjD are available. Considerable changes in the field of AjD could follow after the release of the 11th edition of International Classification of Diseases (ICD-11. A new AjD symptom profile was introduced in ICD-11 with 2 main symptoms as follows: 1 preoccupation and 2 failure to adapt. However, differences between the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and ICD-11 AjD diagnostic criteria could result in diverse research findings in the future. The best treatment approach for AjD remains unclear, and further treatment studies are needed to provide AjD treatment guidelines to clinicians. Keywords: adjustment disorder, review, diagnosis, prevalence, treatment, DSM, ICD

  14. Osteomyelitis: a current challenge

    Directory of Open Access Journals (Sweden)

    Luciana Souza Jorge

    Full Text Available Over the last 30 years, the pathogenesis of osteomyelitis has almost been totally elucidated, and many factors responsible for the persistence of this infection have been identified. Numerous antimicrobial agents with distinct spectrums of action, pharmacokinetics, and pharmacodynamics have been used in its treatment. Surgical techniques, including muscle grafts, the Ilizarov technique, and antibiotic bone cements, have been applied. However, bone infections are still a challenge. Despite the importance of isolation and identification of microorganisms to determine the antimicrobial treatment of bone infections, there are few systematic national studies about the etiological profile of these diseases. This article describes the current knowledge of osteomyelitis and summarizes published national data based on the experience of different Orthopedic and Traumatology Services. In general, S. aureus was described as an important etiological agent; however, the difference in design of national studies makes a comparison between the prevalence of bone infection, the associated risk factors, and the different therapeutic approaches difficult. In conclusion, effort is necessary in order to stimulate systematic national studies in different Orthopedics and Traumatology Services to obtain a better consensus on preventive measures and therapies of bone infections.

  15. Circulating current battery heater

    Science.gov (United States)

    Ashtiani, Cyrus N.; Stuart, Thomas A.

    2001-01-01

    A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase. Higher internal temperatures expand the cold temperature operating range and energy capacity utilization of the battery. As disclosed, either fixed frequency or variable frequency modulation schemes may be used to control the network.

  16. TAFRO syndrome: current perspectives.

    Science.gov (United States)

    Sakashita, Kentaro; Murata, Kengo; Takamori, Mikio

    2018-01-01

    Multicentric Castleman's disease (MCD), a distinct subtype of Castleman's disease, is a rare, nonneoplastic, lymphoproliferative disorder. Patients with MCD present with systemic symptoms and multiple lymphadenopathy. Lymph node biopsy is necessary for the diagnosis of various histological MCD patterns including hyaline vascular, plasma cell, and mixed types. Human herpesvirus 8 (HHV8) infection was identified as an important etiology of MCD among immunocompromised patients such as those positive for human immunodeficiency virus. Although HHV8-negative MCD was reported in immunocompetent patients, the underlying etiology remains unknown. Several experts speculate that MCD in immunocompetent patients might be due to proinflammatory hypercytokinemia because of infection by a virus other than HHV8, inflammation, or neoplastic disease. In 2010, a distinct variant of HHV8-negative MCD reported in Japan was characterized by thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly (TAFRO). Recent case reports and a systematic review suggest that TAFRO syndrome might have a unique pathogenesis among HHV8-negative MCD variants. This review introduces TAFRO syndrome as a subtype of HHV8-negative MCD and offers an overview of the current perspectives on this syndrome.

  17. Superconductive AC current limiter

    International Nuclear Information System (INIS)

    Bekhaled, M.

    1987-01-01

    This patent describes an AC current limiter for a power transport line including a power supply circuit and feeding a load circuit via an overload circuit-breaker member. The limiter comprises a transformer having a primary winding connected in series between the power supply circuit and the load circuit and at least one secondary winding of superconductor material contained in a cryogenic enclosure and short-circuited on itself. The leakage reactance of the transformer as seen from the primary winding is low, and the resistance of the at least one secondary winding when in the non-superconducting state and as seen from the primary is much greater than the nominal impedance of the transformer. The improvement whereby the at least one secondary winding of the transformer comprises an active winding in association with a set of auxiliary windings. The set of auxiliary windings is constituted by an even number of series-connected auxiliary windings wound in opposite directions, with the total number of turns in one direction being equal to the total number of turns in the opposite direction, and with the thermal capacity of the secondary winding as a whole being sufficiently high to limit the expansion thereof to a value which remains small during the time it takes the circuit-breaking member to operate

  18. [Current management of epilepsy].

    Science.gov (United States)

    Mizobuchi, Masahiro

    2013-09-01

    Epilepsy is one of the most common neurological disorders. Global neurological knowledge is essential for differential diagnosis of epileptic syndromes due to the diversity of ictal semiology, causes and syndromes. Neurologists play an important role in planning the medical care for patients with epilepsy, as medication is the most fundamental therapeutic strategy. Some patients with early-onset epilepsy require joint care by pediatric neurologists, those with intractable epilepsy by neurosurgeons, and those with psychological comorbidity by psychiatrists, and neurologists should play a coordinating role. While there is a great need for neurologists to participate in epilepsy care, neurologists in Japan currently do not participate substantially in the epilepsy management system. It is necessary to train more neurologists who can provide epilepsy care and conduct basic and clinical research on epilepsy by providing continuous education on epilepsy for general neurologists as well as pre- and post-graduate medical students. Most of the patients who require long-term treatment experience many medical problems and social handicaps, such as adverse effects of medication, social stigma, educational disadvantages and difficulties in obtaining driver's license. To improve the quality of life of patients with epilepsy, it is desirable to build broad medical-social networks participated by patients, doctors, neurological nurses, psychologists, social workers, school teachers, managers of employment support facilities and care givers.

  19. Sustainable winegrowing: current perspectives

    Directory of Open Access Journals (Sweden)

    Mariani A

    2015-05-01

    Full Text Available Angela Mariani,1 Antonella Vastola2 1Department of Economic and Legal Studies, University Parthenope, Naples, 2School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Italy Abstract: The winegrowing sector worldwide is strongly committed to improving environmental and social sustainability. The aim of this work, based on a literature review, is to highlight current sustainability perspectives and the related main issues. There is a broad consensus that the challenge to achieve a greater spread of sustainable practices is to enhance environmental and social sustainability while maintaining economic viability. From the producers' point of view, the priority is to bridge the still substantial knowledge gaps in terms of perceived environmental benefits, economic benefits, and costs. Thus, an increased research effort focusing on the costs and benefits of different winegrowing practices and technical assistance with implementation might support their diffusion. Moreover, targeted marketing strategies are needed to: enhance consumers' involvement and their attitude toward sustainable wine; improve understanding and use of sustainable labels and claims; and raise awareness of some environmental credentials of wine packaging, mainly with reference to lightweight glass bottles. Keywords: winegrower, sustainability, wine, consumer, marketing strategies

  20. Current-ripple effect on superconductive dc critical current measurements

    International Nuclear Information System (INIS)

    Goodrich, L.F.; Bray, S.L.; Clark, A.F.

    1988-01-01

    The effect of sample-current power-supply ripple on dc critical current measurement in multifilamentary NbTi superconductors was evaluated. In general the ripple in a current supply became more significant above 500 A because effective filtering was hard to achieve. Ripple also caused noise at the input of the voltmeter used for the measurements. The quantitative effect of current ripple was studied using a battery current supply modified to allow the creation of ripple current with variable frequency and amplitude. Problems common to all large-conductor critical current measurements are discussed

  1. Electric current sensors: a review

    International Nuclear Information System (INIS)

    Ripka, Pavel

    2010-01-01

    The review makes a brief overview of traditional methods of measurement of electric current and shows in more detail relatively new types of current sensors. These include Hall sensors with field concentrators, AMR current sensors, magneto-optical and superconducting current sensors. The influence of the magnetic core properties on the error of the current transformer shows why nanocrystalline materials are so advantageous for this application. Built-in CMOS current sensors are important tools for monitoring the health of integrated circuits. Of special industrial value are current clamps which can be installed without breaking the measured conductor. Parameters of current sensors are also discussed, including geometrical selectivity. This parameter specific for current sensors means the ability to suppress the influence of currents external to the sensor (including the position of the return conductor) and also suppress the influence on the position of the measured conductor with respect to the current. (topical review)

  2. Plasma current profile during current reversal in a tokamak

    International Nuclear Information System (INIS)

    Huang Jianguo; Yang Xuanzong; Zheng Shaobai; Feng Chunhua; Zhang Houxian; Wang Long

    1999-01-01

    Alternating current operation with one full cycle and a current level of 2.5 kA have been achieved in the CT-6B tokamak. The poloidal magnetic field in the plasma is measured with two internal magnetic probes in repeated discharges. The current distribution is reconstructed with an inversion algorithm. The inverse current first appears on the weak field side. The existence of magnetic surfaces and rotational transform provide particle confinement in the current reversal phase

  3. Muscle dysmorphia: current insights

    Directory of Open Access Journals (Sweden)

    Tod D

    2016-08-01

    than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation. Keywords: psychopathology, mental health, body image, self-perceptions 

  4. Muscle dysmorphia: current insights.

    Science.gov (United States)

    Tod, David; Edwards, Christian; Cranswick, Ieuan

    2016-01-01

    Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people's beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples), which are largely confined to Western (North American, British, and Australian) males. Although much research has been undertaken since the term "muscle dysmorphia" entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation.

  5. Current Treatments of Bruxism.

    Science.gov (United States)

    Guaita, Marc; Högl, Birgit

    2016-02-01

    Despite numerous case reports, the evidence for treatment of bruxism is still low. Different treatment modalities (behavioral techniques, intraoral devices, medications, and contingent electrical stimulation) have been applied. A clinical evaluation is needed to differentiate between awake bruxism and sleep bruxism and rule out any medical disorder or medication that could be behind its appearance (secondary bruxism). A polysomnography is required only in a few cases of sleep bruxism, mostly when sleep comorbidities are present. Counselling with regard to sleep hygiene, sleep habit modification, and relaxation techniques has been suggested as the first step in the therapeutic intervention, and is generally considered not harmful, despite low evidence of any efficacy. Occlusal splints are successful in the prevention of dental damage and grinding sounds associated with sleep bruxism, but their effects on reducing bruxism electromyographic (EMG) events are transient. In patients with psychiatric and sleep comorbidities, the acute use of clonazepam at night has been reported to improve sleep bruxism, but in the absence of double-blind randomized trials, its use in general clinical practice cannot be recommended. Severe secondary bruxism interfering with speaking, chewing, or swallowing has been reported in patients with neurological disorders such as in cranial dystonia; in these patients, injections of botulinum toxin in the masticatory muscles may decrease bruxism for up to 1-5 months and improve pain and mandibular functions. Long-term studies in larger and better specified samples of patients with bruxism, comparing the effects of different therapeutic modalities on bruxism EMG activity, progression of dental wear, and orofacial pain are current gaps of knowledge and preclude the development of severity-based treatment guidelines.

  6. Theme: Staying Current--Horticulture.

    Science.gov (United States)

    Shry, Carroll L., Jr.; And Others

    1986-01-01

    This theme issue on staying current in horticulture includes articles on sex equity in horticulture, Future Farmers of America, career opportunities in horticulture, staying current with your school district's needs, staying current in horticulture instruction, staying current with landscape trade associations, emphasizing the basics in vocational…

  7. Non-inductive current probe

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl

    1977-01-01

    The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is......The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is...

  8. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  9. Current Issues in Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Barbour, J B [Department of Physics and Astronomy, University of Rochester (United States)

    2007-02-07

    These colloquium proceedings will be valuable, the blurb says, for graduate students and researchers in cosmology and theoretical astrophysics. Specifically, the book 'looks at both the strengths and weaknesses of the current big bang model in explaining certain puzzling data' and gives a 'comprehensive coverage of the expanding field of cosmology'. The reality is rather different. Conference proceedings rarely compare in value with a solid monograph or good review articles, and Current Issues in Cosmology is no exception. The colloquium was convened by the two editors, who have both long harboured doubts about the big bang, and was held in Paris in June 2004. The proceedings contain 19 presented papers and relatively brief summary comments by four panel speakers. The questions and answers at the end of each talk and a general discussion at the end were recorded and transcribed but contain little of interest. The nature of the colloquium is indicated by panellist Francesco Bertola's comment: 'While in the 1950s it was possible to speak of rival theories in cosmology, now the big-bang picture has no strong rivals. This is confirmed by the fact that out of 1500 members of the IAU Division VIII (Galaxies and the Universe) only a dozen, although bright people, devote their time to the heterodox views.' This was largely a platform for them to give their views. At least half of the dozen, all the 'usual suspects', were present: Geoffery and Margaret Burbidge, Jayant Narlikar, Halton Arp, Chandra Wickramasinghe and, in spirit only but playing a role somewhat like the ghost of Hamlet's father, the late Fred Hoyle. Doubters presented 12 of the 19 papers. Orthodoxy should certainly be challenged and the sociology of science questioned, but I found two main problems with this book. The papers putting the orthodox view are too short, even perfunctory. The most that a serious graduate student would get out of them is a reference

  10. Current Issues in Cosmology

    International Nuclear Information System (INIS)

    Barbour, J B

    2007-01-01

    These colloquium proceedings will be valuable, the blurb says, for graduate students and researchers in cosmology and theoretical astrophysics. Specifically, the book 'looks at both the strengths and weaknesses of the current big bang model in explaining certain puzzling data' and gives a 'comprehensive coverage of the expanding field of cosmology'. The reality is rather different. Conference proceedings rarely compare in value with a solid monograph or good review articles, and Current Issues in Cosmology is no exception. The colloquium was convened by the two editors, who have both long harboured doubts about the big bang, and was held in Paris in June 2004. The proceedings contain 19 presented papers and relatively brief summary comments by four panel speakers. The questions and answers at the end of each talk and a general discussion at the end were recorded and transcribed but contain little of interest. The nature of the colloquium is indicated by panellist Francesco Bertola's comment: 'While in the 1950s it was possible to speak of rival theories in cosmology, now the big-bang picture has no strong rivals. This is confirmed by the fact that out of 1500 members of the IAU Division VIII (Galaxies and the Universe) only a dozen, although bright people, devote their time to the heterodox views.' This was largely a platform for them to give their views. At least half of the dozen, all the 'usual suspects', were present: Geoffery and Margaret Burbidge, Jayant Narlikar, Halton Arp, Chandra Wickramasinghe and, in spirit only but playing a role somewhat like the ghost of Hamlet's father, the late Fred Hoyle. Doubters presented 12 of the 19 papers. Orthodoxy should certainly be challenged and the sociology of science questioned, but I found two main problems with this book. The papers putting the orthodox view are too short, even perfunctory. The most that a serious graduate student would get out of them is a reference to a far better review article or book on modern

  11. Current-current interaction picture for proton-proton scattering

    International Nuclear Information System (INIS)

    Clarke, D.J.; Lo, S.Y.

    1979-01-01

    The authors propose that color current - color current interaction is reponsible for small angle elastic proton proton scattering at asymptotic energy. Excellent fits are obtained for all data above 12 GeV/c which covers twelve orders of magnitude

  12. Combined RF current drive and bootstrap current in tokamaks

    International Nuclear Information System (INIS)

    Schultz, S. D.; Bers, A.; Ram, A. K.

    1999-01-01

    By calculating radio frequency current drive (RFCD) and the bootstrap current in a consistent kinetic manner, we find synergistic effects in the total noninductive current density in tokamaks [1]. We include quasilinear diffusion in the Drift Kinetic Equation (DKE) in order to generalize neoclassical theory to highly non-Maxwellian electron distributions due to RFCD. The parallel plasma current is evaluated numerically with the help of the FASTEP Fokker-Planck code [2]. Current drive efficiency is found to be significantly affected by neoclassical effects, even in cases where only circulating electrons interact with the waves. Predictions of the current drive efficiency are made for lower hybrid and electron cyclotron wave current drive scenarios in the presence of bootstrap current

  13. Measurement technology of RF interference current in high current system

    Science.gov (United States)

    Zhao, Zhihua; Li, Jianxuan; Zhang, Xiangming; Zhang, Lei

    2018-06-01

    Current probe is a detection method commonly used in electromagnetic compatibility. With the development of power electronics technology, the power level of power conversion devices is constantly increasing, and the power current of the electric energy conversion device in the electromagnetic launch system can reach 10kA. Current probe conventionally used in EMC (electromagnetic compatibility) detection cannot meet the test requirements on high current system due to the magnetic saturation problem. The conventional high current sensor is also not suitable for the RF (Radio Frequency) interference current measurement in high current power device due to the high noise level in the output of active amplifier. In this paper, a passive flexible current probe based on Rogowski coil and matching resistance is proposed that can withstand high current and has low noise level, to solve the measurement problems of interference current in high current power converter. And both differential mode and common mode current detection can be easily carried out with the proposed probe because of the probe's flexible structure.

  14. Current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Ishibashi, Kenji

    1989-01-01

    Current leads for superconducting magnets have been studied since 1960's. The technology of current leads may seem to have been established both in theory and experiment before the middle of 1970's. Nevertheless, a wide variety of superconducting magnets have been introduced in the last 15 years, and the demands for special current leads have increased in accordance to the variety. A steady advance has been made in the design theory and fabrication of current leads. This paper describes the recent current lead technology regarding the design theory, safety in accidents, and high current capability. (author)

  15. Drug Establishments Current Registration Site

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Establishments Current Registration Site (DECRS) is a database of current information submitted by drug firms to register establishments (facilities) which...

  16. Ozone - Current Air Quality Index

    Science.gov (United States)

    GO! Local Air Quality Conditions Zip Code: State : My Current Location Current AQI Forecast AQI Loop More Maps AQI: Good (0 - 50) ... resources for Hawaii residents and visitors more announcements Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke ...

  17. Exchange currents in nuclear physics

    International Nuclear Information System (INIS)

    Truglik, Eh.

    1980-01-01

    Starting from Adler's low-energy theorem for the soft pion production amplitudes the predictions of the meson exchange currents theory for the nuclear physics are discussed. The results are reformulated in terms of phenomenological lagrangians. This method allows one to pass naturally to the more realistic case of hard mesons. The predictions are critically compared with the existing experimental data. The main processes in which vector isovector exchange currents, vector isoscalar exchange currents and axial exchange currents take place are pointed out

  18. Background current of radioisotope manometer

    International Nuclear Information System (INIS)

    Vydrik, A.A.

    1987-01-01

    The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

  19. Relationships between the Birkeland currents, ionospheric currents, and electric fields

    International Nuclear Information System (INIS)

    Bleuler, E.; Li, C.H.; Nisbet, J.S.

    1982-01-01

    Calculations are made of the currents and electric fields in the ionosphere by using a global model of the electron densities including conjugate coupling along field lines. Incoherent scatter and rocket measurements of high-latitude electron densities have been used to derive realistic variations of the polar conductivities as a function of magnetic activity. The Birkeland currents have been specified in terms of three indices, the total current into and out of the hemisphere, the ratio of the magnitudes of the currents in the AM and PM sectors, R/sub ap/ , and R 12 , the ratio of the magnitudes of the currents in region 1 and 2. The relationship between these parameters of the Birkeland current systems and the auroral electrojet indices AE, AL, and AU is examined as well as the polar cap potential and the electric field at lower latitudes. The cusp currents have been modeled in relation to the interplanetary magnetic field and calculations are given of their effect on electric field and current patterns. One aim of this study is to produce a mathematical model of the currents, electric fields and energy inputs produced by field aligned currents that is consistent with, and specifiable in terms of, measured geophysical indices

  20. Phenomenology of neutral current interactions

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1978-01-01

    Neutral-current interactions are discussed within a rather general phenomenological framework without commitment to any particular theoretical model. Three points are kept in mind: what various experiments really measure; the performing of complete experiments to determine the neutral-current couplings; and the testing of models in an objective, emotionally uninvolved manner. The following topics are considered: neutrino-electron scattering, hadronic currents and models, neutrino-induced inclusive hadronic reactions, neutrino-induced exclusive hadronic reactions, and neutral-current phenomena without neutrinos. In conclusion, what has actually been learned about neutral-current interactions is summarized. 9 figures, 2 tables

  1. Influence of internal current and pacing current on pacemaker longevity.

    Science.gov (United States)

    Schuchert, A; Kuck, K H

    1994-01-01

    The effects of lower pulse amplitude on battery current and pacemaker longevity were studied comparing the new, small-sized VVI pacemaker, Minix 8341, with the former model, Pasys 8329. Battery current was telemetrically measured at 0.8, 1.6, 2.5, and 5.0 V pulse amplitude and 0.05, 0.25, 0.5, and 1.0 msec pulse duration. Internal current was assumed to be equal to the battery current at 0.8 V and 0.05 msec. Pacing current was calculated subtracting internal current from battery current. The Minix pacemaker had a significantly lower battery current because of a lower internal current (Minix: 4.1 +/- 0.1 microA; Pasys: 16.1 +/- 0.1 microA); pacing current of both units was similar. At 0.5 msec pulse duration, the programming from 5.0-2.5 V pulse amplitude resulted in a greater relative reduction of battery current in the newer pacemaker (51% vs 25%). Projected longevity of each pacemaker was 7.9 years at 5.0 V and 0.5 msec. The programming from 5.0-2.5 V extended the projected longevity by 2.3 years (Pasys) and by 7.1 years (Minix). The longevity was negligibly longer after programming to 1.6 V. extension of pacemaker longevity can be achieved with the programming to 2.5 V or less if the connected pacemakers need a low internal current for their circuitry.

  2. Current distribution tomography for determination of internal current density distributions

    International Nuclear Information System (INIS)

    Gailey, P.C.

    1993-01-01

    A method is presented for determination of current densities inside a cylindrical object using measurements of the magnetic fields outside the object. The cross section of the object is discretized with the current assumed constant over each defined region. Magnetic fields outside the object are related to the internal current densities through a geometry matrix which can be inverted to yield a solution for the current densities in terms of the measured fields. The primary limitation of this technique results from singularities in the geometry matrix that arise due to cylindrical symmetry of the problem. Methods for circumventing the singularities to obtain information about the distribution of current densities are discussed. This process of current distribution tomography is designed to determine internal body current densities using measurements of the external magnetic field distribution. It is non-invasive, and relatively simple to implement. Although related to a more general study of magnetic imaging which has been used to investigate endogenous currents in the brain and other parts of the body, it is restricted to currents either applied directly or induced by exposure to an external field. The research is related to public concern about the possibility of health effects resulting from exposure to power frequency electric and magnetic fields

  3. 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

  4. Current interruption by density depression

    International Nuclear Information System (INIS)

    Wagner, J.S.; Tajima, T.; Akasofu, S.I.

    1985-04-01

    Using a one-dimensional electrostatic particle code, we examine processes associated with current interruption in a collisionless plasma when a density depression is present along the current channel. Current interruption due to double layers was suggested by Alfven and Carlqvist (1967) as a cause of solar flares. At a local density depression, plasma instabilities caused by an electron current flow are accentuated, leading to current disruption. Our simulation study encompasses a wide range of the parameters in such a way that under appropriate conditions, both the Alfven and Carlqvist (1967) regime and the Smith and Priest (1972) regime take place. In the latter regime the density depression decays into a stationary structure (''ion-acoustic layer'') which spawns a series of ion-acoustic ''solitons'' and ion phase space holes travelling upstream. A large inductance of the current circuit tends to enhance the plasma instabilities

  5. High current plasma electron emitter

    International Nuclear Information System (INIS)

    Fiksel, G.; Almagri, A.F.; Craig, D.

    1995-07-01

    A high current plasma electron emitter based on a miniature plasma source has been developed. The emitting plasma is created by a pulsed high current gas discharge. The electron emission current is 1 kA at 300 V at the pulse duration of 10 ms. The prototype injector described in this paper will be used for a 20 kA electrostatic current injection experiment in the Madison Symmetric Torus (MST) reversed-field pinch. The source will be replicated in order to attain this total current requirement. The source has a simple design and has proven very reliable in operation. A high emission current, small size (3.7 cm in diameter), and low impurity generation make the source suitable for a variety of fusion and technological applications

  6. Photoinduced current and emission induced by current in a ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 3. Photoinduced current and emission induced by current in a nanowire transistor: Temperature dependence. Darehdor Mahvash Arabi Shahtahmassebi Nasser. Regular Volume 86 Issue 3 March 2016 pp ...

  7. Stability analysis of direct current control in current source rectifier

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Current source rectifier with high switching frequency has a great potential for improving the power efficiency and power density in ac-dc power conversion. This paper analyzes the stability of direct current control based on the time delay effect. Small signal model including dynamic behaviors...

  8. Marketing in current financial crisis

    OpenAIRE

    Mariánek, Lukáš

    2009-01-01

    The paper is describing the effects of recessions and current financial crisis on companies and their marketing. The topic covers the history of marketing throughout the world biggest recessions and describes the current marketing efforts of Czech companies under the current financial crisis. A strategical analysis with the impacts of crisis on long-term strategy planning is provided at the end of the paper.

  9. High current, high bandwidth laser diode current driver

    Science.gov (United States)

    Copeland, David J.; Zimmerman, Robert K., Jr.

    1991-01-01

    A laser diode current driver has been developed for free space laser communications. The driver provides 300 mA peak modulation current and exhibits an optical risetime of less than 400 ps. The current and optical pulses are well behaved and show minimal ringing. The driver is well suited for QPPM modulation at data rates up to 440 Mbit/s. Much previous work has championed current steering circuits; in contrast, the present driver is a single-ended on/off switch. This results in twice the power efficiency as a current steering driver. The driver electrical efficiency for QPPM data is 34 percent. The high speed switch is realized with a Ku-band GaAsFET transistor, with a suitable pre-drive circuit, on a hybrid microcircuit adjacent to the laser diode.

  10. Experimental study of neoclassical currents

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Prager, S.C.

    1985-05-01

    A detailed experimental study is presented of the bootstrap and Pfirsch-Schlueter currents that are predicted by neoclassical transport theory. In a toroidal octupole, on magnetic surfaces within the separatrix, the observed parallel plasma currents are in excellent quantitative agreement with neoclassical theory with regard to the spatial structure (along a magnetic surface), collisionality dependence and toroidal magnetic field dependence. On magnetic surfaces outside the separatrix, the ion portion of the parallel current is in agreement with neoclassical theory but the electron parallel current is observed to obtain a unidirectional component which deviates from and exceeds the theoretical prediction

  11. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  12. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1985-01-01

    Various current drive mechanisms may be grouped into four classes: (1) injection of energetic particle beams; (2) launching of rf waves; (3) hybrid schemes, which are combinations of various rf schemes (rf plus beams, rf and/or beam plus ohmic heating, etc.); and (4) other schemes, some of which are specific to reactor plasma conditions requiring the presence of alpha particle or intense synchrotron radiation. Particle injection schemes include current drive by neutral beams and relativistic electron beams. The rf schemes include current drive by the lower hybrid (LH) waves, the electron waves, the waves in the ion cyclotron range of frequencies, etc. Only a few of these approaches, however, have been tested experimentally, with the broadest data base available for LH waves. Included in this report are (1) efficiency criteria for current drive, (2) current drive by neutral beam injection, (3) LH current drive, (4) electron cyclotron current drive, (5) current drive by ion cyclotron waves - minority species heating, and (6) current drive by other schemes (such as hybrids and low frequency waves)

  13. Reducing Current Spread using Current Focusing in Cochlear Implant Users

    Science.gov (United States)

    Landsberger, David M.; Padilla, Monica; Srinivasan, Arthi G.

    2012-01-01

    Cochlear implant performance in difficult listening situations is limited by channel interactions. It is known that partial tripolar (PTP) stimulation reduces the spread of excitation (SOE). However, the greater the degree of current focusing, the greater the absolute current required to maintain a fixed loudness. As current increases, so does SOE. In experiment 1, the SOE for equally loud stimuli with different degrees of current focusing is measured via a forward-masking procedure. Results suggest that at a fixed loudness, some but not all patients have a reduced SOE with PTP stimulation. Therefore, it seems likely that a PTP speech processing strategy could improve spectral resolution for only those patients with a reduced SOE. In experiment 2, the ability to discriminate different levels of current focusing was measured. In experiment 3, patients subjectively scaled verbal descriptors of stimuli of various levels of current focusing. Both discrimination and scaling of verbal descriptors correlated well with SOE reduction, suggesting that either technique have the potential to be used clinically to quickly predict which patients would receive benefit from a current focusing strategy. PMID:22230370

  14. Coastal tomographic mapping of nonlinear tidal currents and residual currents

    Science.gov (United States)

    Zhu, Ze-Nan; Zhu, Xiao-Hua; Guo, Xinyu

    2017-07-01

    Depth-averaged current data, which were obtained by coastal acoustic tomography (CAT) July 12-13, 2009 in Zhitouyang Bay on the western side of the East China Sea, are used to estimate the semidiurnal tidal current (M2) as well as its first two overtide currents (M4 and M6). Spatial mean amplitude ratios M2:M4:M6 in the bay are 1.00:0.15:0.11. The shallow-water equations are used to analyze the generation mechanisms of M4 and M6. In the deep area, where water depths are larger than 60 m, M4 velocity amplitudes measured by CAT agree well with those predicted by the advection terms in the shallow water equations, indicating that M4 in the deep area is predominantly generated by the advection terms. M6 measured by CAT and M6 predicted by the nonlinear quadratic bottom friction terms agree well in the area where water depths are less than 20 m, indicating that friction mechanisms are predominant for generating M6 in the shallow area. In addition, dynamic analysis of the residual currents using the tidally averaged momentum equation shows that spatial mean values of the horizontal pressure gradient due to residual sea level and of the advection of residual currents together contribute about 75% of the spatial mean values of the advection by the tidal currents, indicating that residual currents in this bay are induced mainly by the nonlinear effects of tidal currents. This is the first ever nonlinear tidal current study by CAT.

  15. Current-to-frequency converter

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, S W [Institute of Nuclear Research, Warsaw (Poland)

    1981-07-15

    A current-to-frequency converter covering the range from 3 x 10/sup -10/ A up to 3 x 10/sup -5/ A of the input current is described. The circuit operates with nuclear detectors featuring a high internal resistance.

  16. Limiting currents in superconducting composites

    International Nuclear Information System (INIS)

    Keilin, V.E.; Romanovskii, V.R.

    1992-01-01

    In this paper the results of numerical and analytical calculations of the process of current charging into a round superconducting composite with properties homogenized over cross-section are presented. In the numerical solution taken was into account a common proceeding of the thermal and electromagnetic processes. A wire with real volt-ampere characteristics approximated by exponential dependence was considered. The calculations carried out at various rates of current charging, voltampere characteristics, matrix materials, heat transfer coefficients and other parameters showed: the existence of characteristic limiting value of current below which the wire remains in a superconducting state if the current charging ceases and above which changes into a normal state; this current is somewhat less than a quench current; the existence of finite value for limiting current at any low heat transfer from a surface. The analytical solution of the problem is given. It permitted to write the stability criterion from which the dependence of limiting currents on initial parameters follows. The wire nonisothermality, its heat capacity, thermal and electric conductivities are taken into account additionally, as compared to results published earlier

  17. Method for critical current testing

    International Nuclear Information System (INIS)

    Siddall, M.B.; Smathers, D.B.

    1989-01-01

    Superconducting critical current testing software was developed with four important features not feasible with analog test equipment. First, quasi-steady-state sample current conditions are achieved by incrementing sample current, followed by holding some milliseconds until the transient voltage decays before voltage sampling. Then the self-field correction from a helically wound sample is computed and subtracted from each sampled field reading. A copper wire inductively wound shunt which is used for quench protection has a constant measured resistance from which the shunt leakage current is computed and subtracted from the sample current by measuring the shunt voltage after each sample current reading. Finally, the critical current is recomputed from a least squares curve fit to the power law: E=A*In when the correlation coefficient for the fit is high enough to ensure a better result than the raw datum. Comparison with NBS Standard Reference Material (NbTi) and current round robin Nb/sub 3/Sn testing is examined

  18. Current-mode minimax circuit

    NARCIS (Netherlands)

    Wassenaar, R.F.

    1992-01-01

    The minimum-maximum (minimax) circuit selects the minimum and maximum of two input currents. Four transistors in matched pairs are operated in the saturation region. Because the behavior of the circuit is based on matched devices and is independent of the relationship between the drain current and

  19. High current density ion source

    International Nuclear Information System (INIS)

    King, H.J.

    1977-01-01

    A high-current-density ion source with high total current is achieved by individually directing the beamlets from an electron bombardment ion source through screen and accelerator electrodes. The openings in these screen and accelerator electrodes are oriented and positioned to direct the individual beamlets substantially toward a focus point. 3 figures, 1 table

  20. Calorimetric beam-current integrator

    International Nuclear Information System (INIS)

    Osborne, J.L.

    1984-01-01

    A single-cup calorimeter for beam-current integration and its associated electronics are described. The design allows beam power up to 120 W and is shown to integrate with an accuracy of 1% over a range of beam energy, current, and power. (orig.)

  1. Tunneling current between graphene layers

    OpenAIRE

    Poklonski, Nikolai A.; Siahlo, Andrei I.; Vyrko, Sergey A.; Popov, Andrey M.; Lozovik, Yurii E.

    2013-01-01

    The physical model that allows to calculate the values of the tunneling current be-tween graphene layers is proposed. The tunneling current according to the pro-posed model is proportional to the area of tunneling transition. The calculated value of tunneling conductivity is in qualitative agreement with experimental data.

  2. Eddy current manual, volume 2

    International Nuclear Information System (INIS)

    Cecco, V.S.; Van Drunen, G.; Sharp, F.L.

    1984-09-01

    This report on eddy current testing is divided into three sections: (a) Demonstration of Basic Principles, (b) Practical (Laboratory) Tests and, (c) Typical Certification Questions. It is intended to be used as a supplement to ΣEddy Current Manual, Volume 1Σ (AECL-7523) during CSNDT Foundation Level II and III courses

  3. Current algebra and differential geometry

    International Nuclear Information System (INIS)

    Alekseev, Anton; Strobl, Thomas

    2005-01-01

    We show that symmetries and gauge symmetries of a large class of 2-dimensional sigma models are described by a new type of a current algebra. The currents are labeled by pairs of a vector field and a 1-form on the target space of the sigma model. We compute the current-current commutator and analyse the anomaly cancellation condition, which can be interpreted geometrically in terms of Dirac structures, previously studied in the mathematical literature. Generalized complex structures correspond to decompositions of the current algebra into pairs of anomaly free subalgebras. Sigma models that we can treat with our method include both physical and topological examples, with and without Wess-Zumino type terms. (author)

  4. Tutorial on beam current monitoring

    International Nuclear Information System (INIS)

    Webber, Robert C.

    2000-01-01

    This paper is a tutorial level review covering a wide range of aspects related to charged particle beam current measurement. The tutorial begins with a look at the characteristics of the beam as a signal source, the associated electromagnetic fields, the influence of the typical accelerator environment on those fields, and the usual means of modifying and controlling that environment to facilitate beam current measurement. Short descriptions of three quite different types of current monitors are presented and a quantitative review of the classical transformer circuit is given. Recognizing that environmental noise pick-up may present a large source of error in quantitative measurements, signal handling considerations are given considerable attention using real-life examples. An example of a successful transport line beam current monitor implementation is presented and the tutorial concludes with a few comments about signal processing and current monitor calibration issues

  5. Digitally compensated beam current transformer

    International Nuclear Information System (INIS)

    Kesselman, Martin

    2005-01-01

    The Spallation Neutron Source (SNS) is being built by a collaboration of six laboratories. Beam current monitors (BCMs) will be used to record the current of H-minus and H-plus beams ranging from 15 mA (tune-up in the Front End and Linac) to over 60A fully accumulated in the Ring and dumped to the load as a single pulse in the Ring to Beam Target (RTBT). The time structure of these beams ranges from 645 ns 'mini' bunches at the 1.05 MHz ring revolution rate, to an overall 1 ms long macro-pulse. The requirements for the BCMs will depend upon their location within the system. The need to measure individual mini-pulses, examine the characteristics of the chopper edge, as well as the longer average current pulse of the macropulse, or long duration pulses during Linac tuning place wide requirements upon the response of current transformers. To obtain the desired accuracy and resolution, current transformers must have <1 ns rise time and droops of 0.1%/ms. This places a significant design burden on the current transformer; such a design is almost impossible to achieve. Extremely large expensive cores are needed to meet the low droop, while leakage inductance increases with size, thereby reducing the achievable rise time. In this paper, I discuss a digital compensation approach [M. Kesselman, Spallation neutron source beam current monitor electronics, PAC2001 June 18-22, 2001, Chicago, IL.] that extends the lower cut-off frequency of the current transformer, optimized for high frequency response, so that it can be used in this application with improvements in droop of the order of 1000:1. Transformer saturation (current-time product) is a separate issue and the transformer must be designed to handle the current-time product of the signal to assure it does not saturate

  6. Coincidence charged-current neutrino-induced deuteron disintegration for 2H2 16O

    Science.gov (United States)

    Van Orden, J. W.; Donnelly, T. W.; Moreno, O.

    2017-12-01

    Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it is shown that the oxygen contribution to the total cross section is suppressed by roughly an order of magnitude compared with the deuterium cross section, thereby confirming that CC ν studies of heavy water can effectively yield the cross sections for deuterium, with acceptable backgrounds from oxygen. This opens the possibility of using deuterium to determine the incident neutrino flux distribution, to have it serve as a target for which the nuclear structure issues are minimal, and possibly to use deuterium to provide improved knowledge of specific aspects of hadronic structure, such as to explore the momentum transfer dependence of the isovector axial-vector form factor of the nucleon.

  7. Simple charged-current channels in ν-D2 interactions

    International Nuclear Information System (INIS)

    Derrick, M.; Hyman, L.; Levman, G.

    1978-01-01

    Updated results are presented from a study of low energy ν-D 2 interactions using the ANL 12-Foot Bubble Chamber. These results for the quasi-elastic reaction νn → μ - p and single pion production final states μ - π + p, μ - π 0 p and μ - π + n are from a total exposure of 2.3 x 10 18 protons on target. The axial-vector form factor mass in quasi-elastic scattering, assuming a dipole form, is determined to be M/sub A/ = 0.98 +- 0.08 GeV. The single pion production channels are in good agreement with the predictions of the Adler model of weak pion production. In particular, the I = 1/2 pion-nucleon amplitude is substantial and relative to the I = 3/2, is determined to be [A/sub 1/2/]/[A/sub 3/2/] = 0.57 +- 0.06. 4 references

  8. Experiments with eddy currents: the eddy current brake

    International Nuclear Information System (INIS)

    Gonzalez, Manuel I

    2004-01-01

    A moderate-cost experimental setup is presented to help students to understand some qualitative and quantitative aspects of eddy currents. The setup operates like an eddy current brake, a device commonly used in heavy vehicles to dissipate kinetic energy by generating eddy currents. A set of simple experiments is proposed to measure eddy current losses and to relate them to various relevant parameters. Typical results for each of the experiments are presented, and comparisons with theoretical predictions are included. The experiments, which are devoted to first-year undergraduate students, deal also with other pedagogically relevant topics in electricity and magnetism, such as basic laws, electrical measurement techniques, the sources of the magnetic field and others

  9. Study of longshore current equations for currents in Visakhapatnam beach

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Rao, T.V.N.

    Longshore currents were measured along the Visakhapatnam Beach, Andhra Pradesh, India at weekly intervals from March 1978 to March 1979. Visual observations on breaker characteristics were also made during this period. Using modified Longuet...

  10. The influence of convective current generator on the global current

    Directory of Open Access Journals (Sweden)

    V. N. Morozov

    2006-01-01

    Full Text Available The mathematical generalization of classical model of the global circuit with taking into account the convective current generator, working in the planetary boundary layer was considered. Convective current generator may be interpreted as generator, in which the electromotive force is generated by processes, of the turbulent transport of electrical charge. It is shown that the average potential of ionosphere is defined not only by the thunderstorm current generators, working at the present moment, but by the convective current generator also. The influence of the convective processes in the boundary layer on the electrical parameters of the atmosphere is not only local, but has global character as well. The numerical estimations, made for the case of the convective-unstable boundary layer demonstrate that the increase of the average potential of ionosphere may be of the order of 10% to 40%.

  11. Current neutralization of nanosecond risetime, high-current electron beam

    International Nuclear Information System (INIS)

    Lidestri, J.P.; Spence, P.W.; Bailey, V.L.; Putnam, S.D.; Fockler, J.; Eichenberger, C.; Champney, P.D.

    1991-01-01

    This paper reports that the authors have recently investigated methods to achieve current neutralization in fast risetime (<3 ns) electron beams propagating in low-pressure gas. For this investigation, they injected a 3-MV, 30-kA intense beam into a drift cell containing gas pressures from 0.10 to 20 torr. By using a fast net current monitor (100-ps risetime), it was possible to observe beam front gas breakdown phenomena and to optimize the drift cell gas pressure to achieve maximum current neutralization. Experimental observations have shown that by increasing the drift gas pressure (P ∼ 12.5 torr) to decrease the mean time between secondary electron/gas collisions, the beam can propagate with 90% current neutralization for the full beam pulsewidth (16 ns)

  12. Current noise in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

    2017-06-15

    We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Passive fault current limiting device

    Science.gov (United States)

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  14. Current collectors for improved safety

    Science.gov (United States)

    Abdelmalak, Michael Naguib; Allu, Srikanth; Dudney, Nancy J.; Li, Jianlin; Simunovic, Srdjan; Wang, Hsin

    2017-12-19

    A battery electrode assembly includes a current collector with conduction barrier regions having a conductive state in which electrical conductivity through the conduction barrier region is permitted, and a safety state in which electrical conductivity through the conduction barrier regions is reduced. The conduction barrier regions change from the conductive state to the safety state when the current collector receives a short-threatening event. An electrode material can be connected to the current collector. The conduction barrier regions can define electrical isolation subregions. A battery is also disclosed, and methods for making the electrode assembly, methods for making a battery, and methods for operating a battery.

  15. Record current in the LHC

    CERN Multimedia

    On 19 December, just before CERN's end-of-year break, Sector 4-5, which had been cooled to 1.9 K, beat the LHC current record for 2007. The current was raised to 8500 amperes in the main magnets. The current of the dipole circuit was repeatedly ramped up and quenches were provoked. The magnets were maintained at 4.5 K over the holiday period so that they could be quickly brought back down to the nominal temperature after the shutdown. The testing of the sector has now resumed.

  16. New particles and new currents

    International Nuclear Information System (INIS)

    Cashmore, R.J.

    1979-01-01

    In this report I want to review the impact of an ep machine on our present ideas and then speculate in what ways such an accelerator could investigate physics beyond our present framework. This speculation will lead to some criteria for the major parameters of such an accelerator, in particular the luminosity, energy and polarization of the electron beams. We will conclude that its principal advantages are: (i) The investigation of charged currents to mass scales beyond those accessible at LEP, (ii) the observation of new currents (charged or neutral) of either chirality coupling to leptons and quarks, (iii) the observation of new particles associated with such currents. (orig.)

  17. FEMA Current Disaster Declarations -shp

    Data.gov (United States)

    Department of Homeland Security — This dataset lists the current Disaster Declarations in Shapefile. This data was compiled and distributed by FEMA Mapping and Analysis Center (MAC). Metadata file...

  18. Natural current profiles in tokamaks

    International Nuclear Information System (INIS)

    Biskamp, D.

    1986-01-01

    It is proposed that a certain class of equilibrium, which follow from an elementary variational principle, are the natural current profiles in tokamaks, to which actual discharge profiles tend to relax. (orig.)

  19. Superconducting dc fault current limiter

    International Nuclear Information System (INIS)

    Cointe, Y.

    2007-12-01

    Within the framework of the electric power market liberalization, DC networks have many interests compared to alternative ones, but their protections need to use new systems. Superconducting fault current limiters enable by an overstepping of the critical current to limit the fault current to a preset value, lower than the theoretical short-circuit current. For these applications, coated conductors offer excellent opportunities. We worked on the implementation of these materials and built a test bench. We carried out limiting experiments to estimate the quench homogeneity at various short-circuit parameters. An important point is the temperature measurement by deposited sensors on the ribbon, results are in good correlation with the theoretical models. Improved quench behaviours for temperatures close to the critical temperature have been confirmed. Our results enable to better understand the limitation mechanisms of coated conductors. (author)

  20. Five currents of organizational psychology

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2017-01-01

    Organizational psychology may be seen as consisting of a number of mutually conflictual currents developed over several decades. This article discusses five currents in organizational psychology that have both been dominant in Scandinavia and have had particular significance in relation...... to the field of organizational development: The social psychological, the socio-technical, the humanistic, the work psychological and the social constructionist currents. Central arguments and works from leading scholars are discussed. It is argued that although treated differently the notions of the small...... group, group dynamics, resistance to change and process consultation constitute pivotal and through going tenets in all the currents. These notions, it is argued, link the discipline of organizational psychology together into a mutually discordant, but anyway relatively consistent research area...

  1. Cancer Disparities - Cancer Currents Blog

    Science.gov (United States)

    Blog posts on cancer health disparities research—including factors that influence disparities, disparities-related research efforts, and diversity in the cancer research workforce—from NCI Cancer Currents.

  2. National Fire News- Current Wildfires

    Science.gov (United States)

    ... 1 to 5) Current hours for the National Fire Information Center are (MST) 8:00 am - 4: ... for more information. June 15, 2018 Nationally, wildland fire activity remains about average for this time of ...

  3. EOP Current Magnitude and Direction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contain shipboard current magnitudes and directions collected in the Pacific, both pelagic and near shore environments. Data is collected using an RD...

  4. NOAA NOS SOS, EXPERIMENTAL - Currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. *These services are for testing and evaluation use...

  5. Large-capacity current leads

    International Nuclear Information System (INIS)

    Ballarino, A.

    2008-01-01

    Feeding superconducting magnets with reliable low-loss devices is a key issue for any cryo-electrical system. Conventional or HTS current leads can be used, and cooling methods, materials, and geometries can be chosen to optimize the thermo-electrical performance of the system. The LHC magnets are powered via more than 3000 current leads transporting altogether about 3 MA of current. With thousands of leads, the LHC lead project represents today the largest project of its kind ever undertaken. Following a review of the LHC lead project, an overview of the choices that can be made for the optimization of large capacity current leads is presented. Examples are given of other leads for large scale magnet systems for which the use of HTS is being envisaged

  6. High current vacuum closing switch

    International Nuclear Information System (INIS)

    Dolgachev, G.I.; Maslennikov, D.D.; Romanov, A.S.; Ushakov, A.G.

    2005-01-01

    The paper proposes a powerful pulsed closing vacuum switch for high current commutation consisting of series of the vacuum diodes with near 1 mm gaps having closing time determined by the gaps shortening with the near-electrode plasmas [ru

  7. Cancer Technology - Cancer Currents Blog

    Science.gov (United States)

    Blog posts on technologies that affect cancer research and care—including new technologies for detecting cancer, testing treatments, storing/analyzing data, and improving patient care—from NCI Cancer Currents.

  8. A THICK CURRENT SHELL MODEL

    African Journals Online (AJOL)

    2005-08-25

    Aug 25, 2005 ... control ling the current distribution latitudinally and vertically ... horizontal plane (v 3 constant) as a result oF the ... optimisation subroutine of licensed MATLAB 6.0 ... electrojct axis does not coincide with the dip equator.

  9. LANSCE Beam Current Limiter (XL)

    International Nuclear Information System (INIS)

    Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) is an engineered safety system that provides personnel protection from prompt radiation due to accelerated proton beams. The Beam Current Limiter (XL), as an active component of the RSS, limits the maximum average current in a beamline, thus the current available for a beam spill accident. Exceeding the pre-set limit initiates action by the RSS to mitigate the hazard (insertion of beam stoppers in the low energy beam transport). The beam limiter is an electrically isolated, toroidal transformer and associated electronics. The device was designed to continuously monitor beamline currents independent of any external timing. Fail-safe operation was a prime consideration in its development. Fail-safe operation is defined as functioning as intended (due to redundant circuitry), functioning with a more sensitive fault threshold, or generating a fault condition. This report describes the design philosophy, hardware, implementation, operation, and limitations of the device

  10. Squid based beam current meter

    International Nuclear Information System (INIS)

    Kuchnir, M.

    1983-01-01

    A SQUID based beam current meter has the capability of measuring the current of a beam with as little as 30 x 155 antiprotons (with a signal to noise ratio of 2). If low noise dc current is used to cancel most of the beam or an up-down counter is used to count auto-resets this sensitivity will be available at any time in the acumulation process. This current meter will therefore be a unique diagnostic tool for optimizing the performance of several Tev I components. Besides requiring liquid helium it seems that its only drawback is not to follow with the above sensitivity a sudden beam change larger than 16 μA, something that could be done using a second one in a less sensitive configuration

  11. Current status of baryon spectroscopy

    International Nuclear Information System (INIS)

    Wali, K.C.

    1975-01-01

    The basic ideas of some of the current models and the experimental numerical comparisons are discussed briefly. Included are realistic or constituent quark models, experimental comparison, the experimental and theoretical basis for the assignments, algebraic quark models, and confinement schemes

  12. [Current treatment of hepatic trauma].

    Science.gov (United States)

    Silvio-Estaba, Leonardo; Madrazo-González, Zoilo; Ramos-Rubio, Emilio

    2008-05-01

    The therapeutic and diagnostic approach of liver trauma injuries (by extension, of abdominal trauma) has evolved remarkably in the last decades. The current non-surgical treatment in the vast majority of liver injuries is supported by the accumulated experience and optimal results in the current series. It is considered that the non-surgical treatment of liver injuries has a current rate of success of 83-100%, with an associated morbidity of 5-42%. The haemodynamic stability of the patient will determine the applicability of the non-surgical treatment. Arteriography with angioembolisation constitutes a key technical tool in the context of liver trauma. Patients with haemodynamic instability will need an urgent operation and can benefit from abdominal packing techniques, damage control and post-operative arteriography. The present review attempts to contribute to the current, global and practical management in the care of liver trauma.

  13. Spin currents in metallic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Czeschka, Franz Dominik

    2011-09-05

    A pure spin current, i.e., a flow of angular momentum without accompanying net charge current, is a key ingredient in the field of spintronics. In this thesis, we experimentally investigated two different concepts for pure spin current sources suggested by theory. The first is based on a time-dependent magnetization precession which ''pumps'' a pure spin current into an adjacent non-magnetic conductor. Our experiments quantitatively corroborated important predictions expected theoretically for this approach, including the dependence of the spin current on the sample geometry and the microwave power. Even more important, we could show for the first time that the spin pumping concept is viable in a large variety of ferromagnetic materials and that it only depends on the magnetization damping. Therefore, our experiments established spin pumping as generic phenomenon and demonstrated that it is a powerful way to generate pure spin currents. The second theoretical concept is based on the conversion of charge currents into spin currents in non-magnetic nanostructures via the spin Hall effect. We experimentally investigated this approach in H-shaped, metallic nanodevices, and found that the predictions are linked to requirements not realizable with the present experimental techniques, neither in sample fabrication nor in measurement technique. Indeed, our experimental data could be consistently understood by a spin-independent transport model describing the transition from diffusive to ballistic transport. In addition, the implementation of advanced fabrication and measurement techniques allowed to discover a new non-local phenomenon, the non-local anisotropic magnetoresistance. Finally, we also studied spin-polarized supercurrents carried by spin-triplet Cooper pairs. We found that low resistance interfaces are a key requirement for further experiments in this direction. (orig.)

  14. Current concepts in adult aphasia.

    Science.gov (United States)

    McNeil, M R

    1984-01-01

    This paper provides a review of recent research from the areas of speech and language pathology, cognitive psychology, psycholinguistics, neurology, and rehabilitation medicine which is used to refine and extend current definitions of aphasia. Evidence is presented from these diverse disciplines, which supports a multimodality, performance-based, verbal and non-verbal, cortical and subcortical, and cognitively multidimensional view of aphasia. A summary of current practice in the assessment and treatment of adult aphasia is summarized.

  15. Weak neutral-current interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-08-01

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

  16. Low frequency rf current drive

    International Nuclear Information System (INIS)

    Hershkowitz, N.

    1992-01-01

    An unshielded antenna for rf heating has been developed and tested during this report period. In addition to design specifications being given, some experimental results are presented utilizing: (1) an unprotected Faraday shield, (2) insulating guard limiters, (3) unshielded antenna experiments, (4) method for detecting small rf driven currents, (5) rf fast wave current drive experiments, (6) alfven wave interactions with electrons, and (7) machine conditioning, impurity generation and density control

  17. High temperature superconductor current leads

    International Nuclear Information System (INIS)

    Zeimetz, B.; Liu, H.K.; Dou, S.X.

    1996-01-01

    Full text: The use of superconductors in high electrical current applications (magnets, transformers, generators etc.) usually requires cooling with liquid Helium, which is very expensive. The superconductor itself produces no heat, and the design of Helium dewars is very advanced. Therefore most of the heat loss, i.e. Helium consumption, comes from the current lead which connects the superconductor with its power source at room temperature. The current lead usually consists of a pair of thick copper wires. The discovery of the High Temperature Superconductors makes it possible to replace a part of the copper with superconducting material. This drastically reduces the heat losses because a) the superconductor generates no resistive heat and b) it is a very poor thermal conductor compared with the copper. In this work silver-sheathed superconducting tapes are used as current lead components. The work comprises both the production of the tapes and the overall design of the leads, in order to a) maximize the current capacity ('critical current') of the superconductor, b) minimize the thermal conductivity of the silver clad, and c) optimize the cooling conditions

  18. Spheromak Impedance and Current Amplification

    International Nuclear Information System (INIS)

    Fowler, T K; Hua, D D; Stallard, B W

    2002-01-01

    It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, τ REC , which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI TOR 2 /dt ∼ I 2 /τ REC - I TOR 2 /τ closed where I is the gun current, I TOR is the spheromak toroidal current and τ CLOSED is the ohmic decay time of the spheromak. Achieving high current amplification, I TOR >> I, requires τ REC CLOSED . For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that τ REC actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B ∝ I, or I TOR ∼ I. Program implications are discussed

  19. BOOK REVIEW: The Current Comparator

    Science.gov (United States)

    Petersons, Oskars

    1989-01-01

    This 120-page book is a concise, yet comprehensive, clearly-written and well-illustrated monograph that covers the subject matter from basic principles through design, construction and calibration details to the principal applications. The book will be useful, as a primer, to the uninitiated and, as a reference book to the practitioner involved with transformer-type ratio devices. The length of the book and the style of presentation will not overburden any informed reader. The described techniques and the cited references are primarily from the work at the National Research Council, Canada (NRC). Any omissions, however, are not serious with respect to coverage of the subject matter, since most of the development work has been done at NRC. The role of transformers and transformer-like devices for establishing accurate voltage and current ratios has been recognized for over half a century. Transformer techniques were much explored and developed in the fifties and sixties for accuracy levels suitable for standards laboratories. Three-winding voltage transformers were developed for scaling of impedances in connection with the calculable Thompson Lampard capacitor; three-winding current transformers or current comparators were initially explored for the calibration of current transformers and later for specialized impedance measurements. Extensive development of the current comparator and its applications has been and is still being conducted at the NRC by a team that was started and, until his retirement, led by N L Kusters. The team is now led by W J M Moore. He and P N Miljanic, the authors of this book, have had the principal roles in the development of the current comparator. It is fortunate for the field of metrology that considerabe resources and a talented group of researchers were available to do this development along with mechanisms that were available to transfer this technology to a private sector instrument manufacturer and, thus, disseminate it world wide

  20. Application of fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.

    2007-11-30

    This report presents the results of a study commissioned by the Department for Business, Enterprise and Industry (BERR; formerly the Department of Trade and Industry) into the application of fault current limiters in the UK. The study reviewed the current state of fault current limiter (FCL) technology and regulatory position in relation to all types of current limiters. It identified significant research and development work with respect to medium voltage FCLs and a move to high voltage. Appropriate FCL technologies being developed include: solid state breakers; superconducting FCLs (including superconducting transformers); magnetic FCLs; and active network controllers. Commercialisation of these products depends on successful field tests and experience, plus material development in the case of high temperature superconducting FCL technologies. The report describes FCL techniques, the current state of FCL technologies, practical applications and future outlook for FCL technologies, distribution fault level analysis and an outline methodology for assessing the materiality of the fault level problem. A roadmap is presented that provides an 'action agenda' to advance the fault level issues associated with low carbon networks.

  1. Synergy in RF Current Drive

    International Nuclear Information System (INIS)

    Dumont, R.J.; Giruzzi, G.

    2005-01-01

    Auxiliary methods for efficient non-inductive current drive in tokamaks generally involve the interaction of externally driven waves with superthermal electrons. Among the possible schemes, Lower Hybrid (LH) and Electron Cyclotron (EC) current drive have been so far the most successful. An interesting aspect of their combined use is the fact that since they involve possibly overlapping domains in velocity and configuration spaces, a synergy between them is expected for appropriate parameters. The signature of this effect, significant improvement of the EC current drive efficiency, results from a favorable interplay of the quasilinear diffusions induced by both waves. Recently, improvements of the EC current drive efficiency in the range of 2-4 have been measured in fully non-inductive discharges in the Tore Supra tokamak, providing the first clear evidence of this effect in steady-state conditions. We present here the experimental aspects of these discharges. The associated kinetic modeling and current state of understanding of the LH-EC synergy phenomenon are also discussed. (authors)

  2. Synergy in RF Current Drive

    International Nuclear Information System (INIS)

    Dumont, R.J.; Giruzzi, G.

    2005-01-01

    Auxiliary methods for efficient non-inductive current drive in tokamaks generally involve the interaction of externally driven waves with superthermal electrons. Among the possible schemes, Lower Hybrid (LH) and Electron Cyclotron (EC) current drive have been so far the most successful. An interesting aspect of their combined use is the fact that since they involve possibly overlapping domains in velocity and configuration spaces, a synergy between them is expected for appropriate parameters. The signature of this effect, significant improvement of the EC current drive efficiency, results from a favorable interplay of the quasilinear diffusions induced by both waves. Recently, improvements of the EC current drive efficiency in the range of 2-4 have been measured in fully non-inductive discharges in the Tore Supra tokamak, providing the first clear evidence of this effect in steady-state conditions. We present here the experimental aspects of these discharges. The associated kinetic modeling and current state of understanding of the LH-EC synergy phenomenon are also discussed

  3. Collecting Currents with Water Turbines

    Science.gov (United States)

    Allen, J.; Allen, S.

    2017-12-01

    Our science poster is inspired by Florida Atlantic University's recent program to develop three types of renewable energy. They are using water turbines and the Gulf Stream Current to produce a renewable energy source. Wave, tidal and current driven energy. Our poster is called "Collecting Currents with Water Turbines". In our science poster, the purpose was to see which turbine design could produce the most power. We tested three different variables, the number of blades (four, six, and eight), the material of the blades and the shape of the blades. To test which number of blades produced the most power we cut slits into a cork. We used plastic from a soda bottle to make the blades and then we put the blades in the cork to make the turbines. We observed each blade and how much time it took for the water turbines to pull up 5 pennies. Currently water turbines are used in dams to make hydroelectric energy. But with FAU we could understand how to harness the Gulf Stream current off Florida's coast we could soon have new forms of renewable energy.

  4. Subtractions in the Adler sum rule and violation of charge symmetry

    International Nuclear Information System (INIS)

    Dominguez, C.A.; Moreno, H.; Zepeda, A.

    1976-01-01

    The consequences of a once-subtracted dispersion relation in the derivation of the Adler sum rule are investigated. It is shown that one can expect a breakdown of charge symmetry, of the isotriplet-current hypothesis, and of scaling of the structure functions. These breakdowns are related to the possible presence of a nonzero subtraction function at asymptotic energies and arbitrary q 2 . We also comment about second-class currents and PCAC (partial conservation of axial-vector current) relations

  5. Direct current contamination of kilohertz frequency alternating current waveforms.

    Science.gov (United States)

    Franke, Manfred; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-07-30

    Kilohertz frequency alternating current (KHFAC) waveforms are being evaluated in a variety of physiological settings because of their potential to modulate neural activity uniquely when compared to frequencies in the sub-kilohertz range. However, the use of waveforms in this frequency range presents some unique challenges regarding the generator output. In this study we explored the possibility of undesirable contamination of the KHFAC waveforms by direct current (DC). We evaluated current- and voltage-controlled KHFAC waveform generators in configurations that included a capacitive coupling between generator and electrode, a resistive coupling and combinations of capacitive with inductive coupling. Our results demonstrate that both voltage- and current-controlled signal generators can unintentionally add DC-contamination to a KHFAC signal, and that capacitive coupling is not always sufficient to eliminate this contamination. We furthermore demonstrated that high value inductors, placed in parallel with the electrode, can be effective in eliminating DC-contamination irrespective of the type of stimulator, reducing the DC contamination to less than 1 μA. This study highlights the importance of carefully designing the electronic setup used in KHFAC studies and suggests specific testing that should be performed and reported in all studies that assess the neural response to KHFAC waveforms. Published by Elsevier B.V.

  6. Variable current speed controller for eddy current motors

    Science.gov (United States)

    Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

    1982-03-12

    A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

  7. Photoinduced current and emission induced by current in a ...

    Indian Academy of Sciences (India)

    gap excitations in TiO2 nanoparticles and nanotubes, lead to the injection of electrons to the conducting channel ... numerical works on such systems, where the current excites the system to produce light. Among the .... E − ε1 + iM,1/2. 0. 0. 1.

  8. Current pulse shaping of the load current on PTS

    Directory of Open Access Journals (Sweden)

    Minghe Xia

    2016-02-01

    Full Text Available The typical rise time of PTS machine is ∼110 ns with about 10 MA peak current under short pulse mode when all 24 modules discharge simultaneously. By distributing the trigger times of 12 laser beams logically and adjusting the statues of the pulse output switches, longer rise-time pulse can be obtained on the PTS facility. Based on the required pulse shape, whole circuit simulations will be used to calculate the trigger times of each laser triggering gas switch and the status of the pulse output switches. The rise time of the current is determined by the time difference between the first and last trigged laser triggering gas switches. In order to trigger the laser triggering gas switch, sufficient laser power is needed to be sent into the gap of the gas switches. The gas pressure and voltage difference on the two electrodes of the gas switches also affect the triggering of the gas switches, and the voltage added on the gas switch is determined by its transition time. Traditionally the trigger time difference should be less than the transition time of the two neighboring modules. A new simulation model of PTS shows one can break this transition time limits. Series of current pulse shaping experiments have been investigated on the PTS (Primary Test Stand. As results, more than 5 MA peak current were successfully achieved on the load with a rise time of 600 ns. This study and experiments of the pulse shaping on PTS demonstrate the adaptable ability of the PTS for offering different waveform of mega ampere current pulse for different research purpose.

  9. Fluctuation current in superconducting loops

    International Nuclear Information System (INIS)

    Berger, Jorge

    2012-01-01

    A superconducting loop that encloses noninteger flux holds a permanent current. On the average, this current is also present above T c , and has been measured in recent years. We are able to evaluate the permanent current within the TDGL or the Kramer-Watts-Tobin models for loops of general configuration, i.e., we don't require uniform cross section, material or temperature. We can also consider situations in which the width is not negligible in comparison to the radius. Our results agree with experiments. The situations with which we deal at present include fluctuation superconductivity in two-band superconductors, equilibrium thermal fluctuations of supercurrent along a weak link, and ratchet effects.

  10. High-current railgap studies

    Energy Technology Data Exchange (ETDEWEB)

    Druce, R.; Gordon, L.; Hofer, W.; Wilson, M.

    1983-06-03

    Characteristics of a 40-kV, 750-kA, multichannel rail gap are presented. The gap is a three electrode, field-distortion-triggered design, with a total switch inductance of less than 10 nH. At maximum ratings, the gap typically switches 10 C per shot, at 700 kA, with a jitter of less than 2 ns. Image-converter streak photographs were used to study channel evolution and current division. Transient gas-pressure measurements were made to investigate the arc generated shocks and to detect single channel failure. Channel current sharing and simultaneity are described and their effects on the switch inductance and lifetime are discussed. Lifetime tests of the rail gap were performed. Degradation in the channel current-sharing and erosion measurements are discussed.

  11. High-current railgap studies

    Science.gov (United States)

    Druce, R.; Gordon, L.; Hofer, W.; Wilson, M.

    1983-06-01

    Characteristics of a 40-kV, 750-kA, multichannel rail gap are presented. The gap is a three electrode, field distortion triggered design, with a total switch inductance of less than 10 nH. At maximum ratings, the gap typically switches 10 C per shot, at 700 kA, with a jitter of less than 2 ns. Channel evolution and current division were studied on image converter streak photographs. Transient gas pressure measurements were made to investigate the arc generated shocks and to detect single channel failure. Channel current sharing and simultaneity are described and their effects on the switch inductance in the channel current sharing and erosion measurements are discussed.

  12. Quantum electrodynamics with compensating current

    Energy Technology Data Exchange (ETDEWEB)

    Bechler, A [Warsaw Univ. (Poland). Instytut Fizyki Teoretycznej

    1974-01-01

    A formulation of quantum electrodynamics is proposed in which all the propagators and field operators are gauge invariant. It is based on an old idea of Heisenberg and Euler which consists in the introduction of the linear integrals of potentials as arguments of the exponential functions. This method is generalized by an introduction of the so-called ''compensating currents'', which ensure local, i.e. in every point of space-time, charge conservation. The linear integral method is a particular case of that proposed in this paper. As the starting point we use quantum electrodynamics with a non-zero, small photon mass (Proca theory). It is shown that, due to the presence of the compensating current, the theory is fully renormalizable in Hilbert space with positive definite scalar product. The problem of the definition of the current operator is also briefly discussed.

  13. Investigation of Current Driven Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Agerkvist, Finn T.; Knott, Arnold

    2015-01-01

    Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage an......” woofer where a copper ring in the pole piece has not been implemented to compensate for eddy currents. However the drive method seems to be irrelevant for a 5” woofer where the compliance, force factor as well as the voice coil inductance has been optimized for linearity.......Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage...

  14. Remote field eddy current testing

    International Nuclear Information System (INIS)

    Cheong, Y. M.; Jung, H. K.; Huh, H.; Lee, Y. S.; Shim, C. M.

    2001-03-01

    The state-of-art technology of the remote field eddy current, which is actively developed as an electromagnetic non-destructive testing tool for ferromagnetic tubes, is described. The historical background and recent R and D activities of remote-field eddy current technology are explained including the theoretical development of remote field eddy current, such as analytical and numerical approach, and the results of finite element analysis. The influencing factors for actual applications, such as the effect of frequency, magnetic permeability, receiving sensitivity, and difficulties of detection and classification of defects are also described. Finally, two examples of actual application, 1) the gap measurement between pressure tubes and calandria tube in CANDU reactor and, 2) the detection of defects in the ferromagnetic heat exchanger tubes, are described. The future research efforts are also included

  15. Current disruption in toroidal devices

    International Nuclear Information System (INIS)

    1979-07-01

    Attempts at raising the density or the plasma current in a tokamak above certain critical values generally result in termination of the discharge by a disruption. This sudden end of the plasma current and plasma confinement is accompanied by large induced voltages and currents in the outer structures which, in large tokamaks, can only be handled with considerable effort, and which will probably only be tolerable in reactors as rare accidents. Because of its crucial importance for the construction and operation of tokamaks, this phenomenon and its theoretical interpretation were the subject of a three-day symposium organized by the International Atomic Energy Agency and Max-Planck-Institut fuer Plasmaphysik at Garching from February 14 to 16. (orig./HT)

  16. Magnetoelectric control of spin currents

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, J. E.; Vargas, J. M.; Avilés-Félix, L.; Butera, A. [Centro Atómico Bariloche, Instituto de Nanociencia y Nanotecnología (CNEA) and Conicet, 8400 Bariloche, Río Negro (Argentina)

    2016-06-13

    The ability to control the spin current injection has been explored on a hybrid magnetoelectric system consisting of a (011)-cut ferroelectric lead magnesium niobate-lead titanate (PMNT) single crystal, a ferromagnetic FePt alloy, and a metallic Pt. With this PMNT/FePt/Pt structure we have been able to control the magnetic field position or the microwave excitation frequency at which the spin pumping phenomenon between FePt and Pt occurs. We demonstrate that the magnetoelectric heterostructure operating in the L-T (longitudinal magnetized-transverse polarized) mode couples the PMNT crystal to the magnetostrictive FePt/Pt bilayer, displaying a strong magnetoelectric coefficient of ∼140 Oe cm kV{sup −1}. Our results show that this mechanism can be effectively exploited as a tunable spin current intensity emitter and open the possibility to create an oscillating or a bistable switch to effectively manipulate spin currents.

  17. Neutral currents in semileptonic reactions

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1975-05-01

    The evidence for weak neutral currents is analyzed in semileptonic reactions with special emphasis on their Lorentz and internal symmetry structure. It is found that present observations are consistent with the expectations of gauge theories, but other possibilities can not be ruled out. Of particular interest in this respect is the presence of a large isoscalar component. The excitation of the Δ-resonance by neutral currents is analyzed, and pion-nucleon mass distributions are presented. Charge asymmetries sensitive to isoscalar-isovector interferences are discussed. (U.S.)

  18. Force As A Momentum Current

    International Nuclear Information System (INIS)

    Munera, Hector A.

    2010-01-01

    Advantages of a neo-Cartesian approach to classical mechanics are noted. If conservation of linear momentum is the fundamental principle, Newton's three laws become theorems. A minor paradox in static Newtonian mechanics is identified, and solved by reinterpreting force as a current of momentum. Contact force plays the role of a mere midwife in the exchange of momentum; however, force cannot be eliminated from physics because it provides the numerical value for momentum current. In this sense, in a neo-Cartesian formulation of mechanics the concept of force becomes strengthened rather than weakened.

  19. Eddy currents in accelerator magnets

    CERN Document Server

    Moritz, G

    2010-01-01

    This paper covers the main eddy current effects in accelerator magnets - field modification (time delay and field quality) and resistive power losses. In the first part, starting from the Maxwell equations, a basic understanding of the processes is given and explained with examples of simple geometry and time behaviour. Useful formulas are derived for an analytic estimate of the size of the effects. In the second part the effects in real magnets are analysed and described in comparison with numerical and measured results. Finally, based on the previous parts, design recommendations are given regarding how to minimize eddy current effects.

  20. Are there missing convective currents?

    International Nuclear Information System (INIS)

    Chen, C.Y.

    1992-01-01

    It is revealed in this letter that as far as distribution functions obtained from gyrokinetic equations are concerned, the standard formulae to evaluate currents in plasmas are not applicable due to the fact that those distribution functions are given in a moving coordinate frame and the moving is essentially related to perturbed fields. With heuristic and analytic approaches, appropriate formulae are obtained to evaluate several types of currents in plasmas of which some have been missing in previous approaches. (author). 6 refs, 1 fig

  1. Threshold current for fireball generation

    Science.gov (United States)

    Dijkhuis, Geert C.

    1982-05-01

    Fireball generation from a high-intensity circuit breaker arc is interpreted here as a quantum-mechanical phenomenon caused by severe cooling of electrode material evaporating from contact surfaces. According to the proposed mechanism, quantum effects appear in the arc plasma when the radius of one magnetic flux quantum inside solid electrode material has shrunk to one London penetration length. A formula derived for the threshold discharge current preceding fireball generation is found compatible with data reported by Silberg. This formula predicts linear scaling of the threshold current with the circuit breaker's electrode radius and concentration of conduction electrons.

  2. Eddy current inspection of tubing

    International Nuclear Information System (INIS)

    Bauza, J. L. R.; Herrero, J.; Diaz, J.

    1966-01-01

    The Experimental research work carried out to develop a Eddy current testing equipment is described. Search coils with ferrite or air cores were used and the obtained results are discussed. Valuable information was gained from a improved channel in which a direct measure of the defect and the reference signal phase difference is obtained. Artificial defect used to evaluate resolution and sensitivity were produced by electro-machining and mechanical means. Finned SAP tubing was tested in a routine basis with the described equipment and the results plotted. Basic and theoretical considerations on the Eddy current testing technique are given in the last section of this report. (Author)

  3. Modulation of Current Source Inverter

    Directory of Open Access Journals (Sweden)

    Golam Reza Arab Markadeh

    2011-04-01

    Full Text Available Direct torque control with Current Source Inverter (CSI instead of voltage source inverter is so appropriate because of determining the torque of induction motor with machine current and air gap flux. In addition, Space-Vector Modulation (SVM is a more proper method for CSI because of low order harmonics reduction, lower switching frequency and easier implementation. This paper introduces the SVM method for CSI and uses the proposed inverter for vector control of an induction motor. The simulation results illustrate fast dynamic response and desirable torque and speed output. Fast and accurate response to changes of speed and load torque reference completely proves the prominence of this method.

  4. Current issues in perturbative QCD

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1994-12-01

    This review talk discusses some issues of active research in perturbative QCD. The following topics are discussed: (1) current value of αs; (2) heavy quark production in hadron collisions; (3) production of Ψ and Υ in p anti p collisions; (4) prompt photon production; (5) small-x and related phenomena; and (6) particle multiplicity in heavy quark jets

  5. Interaction of Waves and Currents.

    Science.gov (United States)

    1983-03-01

    glitter due to the greater surface roughness on the current. This surface roughness has value in remote sensing, particularly when infrared observations...34Pneumatic Breakwaters to Protect Dredges," Journal of Waterways and Harbors Division, Vol. 87, No. WW2 , May 1961, pp. 67- 87. Discussion 87 (Nov.) 127

  6. Radiopharmaceuticals - current state and trends

    International Nuclear Information System (INIS)

    Muenze, R.

    1981-07-01

    The current state as well as the tendencies of modern radiopharmaceutical development and application is reviewed. After an evaluation of the fundamental preconditions of decay characteristics and pharmaceutical properties the problems concerning sup(99m)Tc-radiopharmaceuticals, metabolizable compounds and the use of specific biological interactions are discussed. (author)

  7. Imposed currents in galvanic cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current

  8. Multispacecraft current estimates at swarm

    DEFF Research Database (Denmark)

    Dunlop, M. W.; Yang, Y.-Y.; Yang, J.-Y.

    2015-01-01

    During the first several months of the three-spacecraft Swarm mission all three spacecraft camerepeatedly into close alignment, providing an ideal opportunity for validating the proposed dual-spacecraftmethod for estimating current density from the Swarm magnetic field data. Two of the Swarm...

  9. Mechanical generation of spin current

    Directory of Open Access Journals (Sweden)

    Mamoru eMatsuo

    2015-07-01

    Full Text Available We focus the recent results on spin-current generation from mechanical motion such as rigid rotation and elastic deformations. Spin transport theory in accelerating frames is constructed by using the low energy expansion of the generally covariant Dirac equation. Related issues on spin-manipulation by mechanical rotation are also discussed.

  10. Current status of baryon spectroscopy

    International Nuclear Information System (INIS)

    Wali, K.C.

    1975-08-01

    In this review of baryon spectroscopy, the basic ideas of some of the current models and the experimental data for their claims to success are discussed including realistic or constituent quark models, experimental comparison, the experimental and theoretical basis for the assignments, algebraic quark models, and confinement schemes

  11. Electric Currents along Astrophysical Jets

    Directory of Open Access Journals (Sweden)

    Ioannis Contopoulos

    2017-10-01

    Full Text Available Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these fields and their associated electric currents. Several researchers have reported direct evidence for large scale electric currents along astrophysical jets. Quite unexpectedly, their directions are not random as would have been the case if the magnetic field were generated by a magnetohydrodynamic dynamo. Instead, in all kpc-scale detections, the inferred electric currents are found to flow away from the galactic nucleus. This unexpected break of symmetry suggests that a battery mechanism is operating around the central black hole. In the present article, we summarize observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets. We also present recent results of general relativistic radiation magnetohydrodynamic simulations which show the action of the Cosmic Battery in the vicinity of astrophysical black holes.

  12. High current transistor pulse generator

    International Nuclear Information System (INIS)

    Nesterov, V.; Cassel, R.

    1991-05-01

    A solid state pulse generator capable of delivering high current trapezoidally shaped pulses into an inductive load has been developed at SLAC. Energy stored in the capacitor bank of the pulse generator is switched to the load through a pair of Darlington transistors. A combination of diodes and Darlington transistors is used to obtain trapezoidal or triangular shaped current pulses into an inductive load and to recover the remaining energy in the same capacitor bank without reversing capacitor voltage. The transistors work in the switch mode, and the power losses are low. The rack mounted pulse generators presently used at SLAC contain a 660 microfarad storage capacitor bank and can deliver 400 amps at 800 volts into inductive loads up to 3 mH. The pulse generators are used in several different power systems, including pulse to pulse bipolar power supplies and in application with current pulses distributed into different inductive loads. The current amplitude and discharge time are controlled by the central computer system through a specially developed multichannel controller. Several years of operation with the pulse generators have proven their consistent performance and reliability. 8 figs

  13. Current Leads, Links and Buses

    CERN Document Server

    Ballarino, A

    2014-01-01

    Electrical transfer from a room temperature power source to a superconducting system is done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

  14. Eddy current manual: v.1

    International Nuclear Information System (INIS)

    Cecco, V.S.; Van Drunen, G.; Sharp, F.L.

    1983-09-01

    This training and reference manual was assembled to provide those involved in eddy current testing with both the fundamental principles of the technique as well as the knowledge to deal with often complicated test results. A non-rigorous approach is used to simplify complex physical phenomena. Emphasis is placed on proper choice of test frequency and signal interpretation. Defect detection and diagnosis receive particular attention. Design and construction of probes are covered extensively since probes play a key role in eddy current testing. The advantages and limitations of various probe types are discussed. Electromagnetic theory, instrumentation, test methods and signal analysis are covered. Simplified derivations of probe response to test parameters are presented to develop a basic understanding of eddy current behaviour. Eddy current signals are presented on impedance plane diagrams throughout the manual since this is the most common display on modern, general purpose instruments. The use of Σphase lagΣ in signal analysis is covered in detail. To supplement theory, practical examples are presented to develop proficiency in performing inspections, and to illustrate how basic principles are applied to diagnose real signals

  15. Eddy current testing, volume 1

    International Nuclear Information System (INIS)

    Cecco, V.S.; Van Drunen, G.; Sharp, F.L.

    1981-11-01

    This training and reference manual was assembled to provide those involved in eddy current testing with both the fundamental principles of the technique as well as the knowledge to deal with often complicated test results. A non-rigorous approach is used to simplify complex physical phenomena. Emphasis is placed on proper choice of test frequency and interpretation. Defect detection and diagnosis receive particular attention. Design and construction of probes are covered extensively since probes play a key role in eddy current testing. The advantages and limitations of various probe types are discussed. Electromagnetic theory, instrumentation, test methods and signal analysis are covered. Simplified derivations of probe response to test parameters are presented to develop a basic understanding of eddy current behaviour. Eddy current signals are presented on impedance plane diagrams throughout the manual since this is the most common display on modern, general purpose instruments. The use of 'phase leg' in signal analysis is covered in detail. To supplement theory, practical examples are presented to develop proficiency in performing inspections, and to illustrate how basic principles are applied to diagnose real signals

  16. On tridimensional rip current modeling

    Science.gov (United States)

    Marchesiello, Patrick; Benshila, Rachid; Almar, Rafael; Uchiyama, Yusuke; McWilliams, James C.; Shchepetkin, Alexander

    2015-12-01

    Do lateral shear instabilities of nearshore circulation account for a substantial part of Very Low-Frequency (VLF) variability? If yes, it would promote stirring and mixing of coastal waters and surf-shelf exchanges. Another question is whether tridimensional transient processes are important for instability generation. An innovative modeling system with tridimensional wave-current interactions was designed to investigate transient nearshore currents and interactions between nearshore and innershelf circulations. We present here some validation of rip current modeling for the Aquitanian coast of France, using in-situ and remote video sensing. We then proceed to show the benefits of 3D versus 2D (depth-mean flow) modeling of rip currents and their low-frequency variability. It appears that a large part of VLF motions is due to intrinsic variability of the tridimensional flow. 3D models may thus provide a valuable, only marginally more expensive alternative to conventional 2D approaches that miss the vertical flow structure and its nonlinear interaction with the depth-averaged flow.

  17. Current drive for rotamak plasmas

    Indian Academy of Sciences (India)

    Abstract. Experiments which have been undertaken over a number of years have shown that a rotating magnetic field can drive a significant non-linear Hall current in a plasma. Successful experiments of this concept have been made with a device called rotamak. In its original configuration this device was a field reversed ...

  18. Current Leads, Links and Buses

    Energy Technology Data Exchange (ETDEWEB)

    Ballarino, A [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    Electrical transfer from a room temperature power source to a superconducting system is done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

  19. Teen Addiction. Current Controversies Series.

    Science.gov (United States)

    Winters, Paul A., Ed.

    The Current Controversies series explores social, political, and economic controversies that dominate the national and international scenes today from a variety of perspectives. Recent surveys have shown that, after years of decline, drug use among teenagers has increased during the 1990s, and that alcohol and tobacco use have remained…

  20. Universal bounds on current fluctuations.

    Science.gov (United States)

    Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

    2016-05-01

    For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

  1. Uncovering a New Current: The Southwest MAdagascar Coastal Current

    Science.gov (United States)

    Ramanantsoa, Juliano D.; Penven, P.; Krug, M.; Gula, J.; Rouault, M.

    2018-02-01

    Cruise data sets, satellite remote sensing observations, and model data analyses are combined to highlight the existence of a coastal surface poleward flow in the southwest of Madagascar: the Southwest MAdagascar Coastal Current (SMACC). The SMACC is a relatively shallow (water surface signature of the SMACC extends from 22°S (upstream) to 26.4°S (downstream). The SMACC exhibits a seasonal variability: more intense in summer and reduced in winter. The average volume transport of its core is about 1.3 Sv with a mean summer maximum of 2.1 Sv. It is forced by a strong cyclonic wind stress curl associated with the bending of the trade winds along the southern tip of Madagascar. The SMACC directly influences the coastal upwelling regions south of Madagascar. Its existence is likely to influence local fisheries and larval transport patterns, as well as the connectivity with the Agulhas Current, affecting the returning branch of the global overturning circulation.

  2. Low Voltage Current Mode Switched-Current-Mirror Mixer

    Directory of Open Access Journals (Sweden)

    Chunhua Wang

    2009-09-01

    Full Text Available A new CMOS active mixer topology can operate at 1 V supply voltage by use of SCM (switched currentmirror. Such current-mode mixer requires less voltage headroom with good linearization. Mixing is achieved with four improved current mirrors, which are alternatively activated. For ideal switching, the operation is equivalent to a conventional active mixer. This paper analyzes the performance of the SCM mixer, in comparison with the conventional mixer, demonstrating competitive performance at a lower supply voltage. Moreover, the new mixer’s die, without any passive components, is very small, and the conversion gain is easy to adjust. An experimental prototype was designed and simulated in standard chartered 0.18μm RF CMOS Process with Spectre in Cadence Design Systems. Experimental results show satisfactory mixer performance at 2.4 GHz.

  3. Stemless shoulder arthroplasty: current status.

    Science.gov (United States)

    Churchill, R Sean

    2014-09-01

    Since the original Neer humeral replacement in the 1950s, the standard primary anatomic total shoulder arthroplasty design has slowly evolved. Most recently, the humeral stem has become progressively shorter to help combat stem-related complications. Currently, there are several companies who have developed and marketed a stemless humeral arthroplasty component. Manufacturers' data for 5 stemless shoulder arthroplasty components currently on the market were analyzed and reviewed. A literature review of short-term results for stemless shoulder arthroplasty was completed. Of the stemless shoulder arthroplasty systems available on the market, 3 are currently undergoing clinical trials in the United States. The Tornier Simpliciti (Tornier, Edina, MN, USA) clinical trial began in 2011. The study with 2-year minimum follow-up results is scheduled for completion in November 2014. The Arthrex Eclipse (Arthrex, Naples, FL, USA) clinical trial was started in January 2013. The tentative study completion date is 2017. The Biomet Nano (Biomet, Warsaw, IN, USA) clinical trial began in October 2013 and also has a tentative completion date of 2017. No other clinical trial is currently under way in the United States. Early results for stemless shoulder arthroplasty indicate clinical results similar to standard stemmed shoulder arthroplasty. Radiographic analysis indicates implant stability without migration or subsidence at 2- to 3-year minimum follow-up.. Several stemless shoulder arthroplasty implants are available outside the United States. Early clinical and radiographic results are promising, but well-designed clinical studies and midterm results are lacking. Three clinical trials are currently under way in the United States with initial availability for use anticipated in 2015. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  4. Imposed currents in galvanic cells

    International Nuclear Information System (INIS)

    Biesheuvel, P.M.; Soestbergen, M. van; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current against an external load, but also operation in two modes which require a net input of electrical energy: (i) the electrolytic charging mode, where a negative current is imposed to generate a voltage exceeding the open-circuit voltage, and (ii) the 'super-galvanic' discharging mode, where a positive current exceeding the short-circuit current is imposed to generate a negative voltage. Analysis of the various (dis-)charging modes of galvanic cells is important to predict the efficiency of electrical to chemical energy conversion and to provide sensitive tests for experimental validation of fuel cell models. In the model, we consider effects of diffuse charge on electrochemical charge-transfer rates by combining a generalized Frumkin-Butler-Volmer equation for reaction kinetics across the compact Stern layer with the full Poisson-Nernst-Planck transport theory, without assuming local electroneutrality. Since this approach is rare in the literature, we provide a brief historical review. To illustrate the general theory, we present results for a monovalent binary electrolyte, consisting of cations, which react at the electrodes, and non-reactive anions, which are either fixed in space (as in a solid electrolyte) or are mobile (as in a liquid electrolyte). The full model is solved numerically and compared to analytical results in the limit of thin diffuse layers, relative to the membrane thickness. The spatial profiles of the ion concentrations and electrostatic potential reveal a complex dependence on the kinetic parameters and the imposed current, in which the diffuse charge at each electrode and the total membrane charge can have either sign, contrary perhaps to intuition

  5. Ancient and Current Chaos Theories

    Directory of Open Access Journals (Sweden)

    Güngör Gündüz

    2006-07-01

    Full Text Available Chaos theories developed in the last three decades have made very important contributions to our understanding of dynamical systems and natural phenomena. The meaning of chaos in the current theories and in the past is somewhat different from each other. In this work, the properties of dynamical systems and the evolution of chaotic systems were discussed in terms of the views of ancient philosophers. The meaning of chaos in Anaximenes’ philosophy and its role in the Ancient natural philosophy has been discussed in relation to other natural philosophers such as of Anaximander, Parmenides, Heraclitus, Empedocles, Leucippus (i.e. atomists and Aristotle. In addition, the fundamental concepts of statistical mechanics and the current chaos theories were discussed in relation to the views in Ancient natural philosophy. The roots of the scientific concepts such as randomness, autocatalysis, nonlinear growth, information, pattern, etc. in the Ancient natural philosophy were investigated.

  6. Current Cervical Carcinoma Screening Guidelines

    Directory of Open Access Journals (Sweden)

    Megan J. Schlichte

    2015-05-01

    Full Text Available A formidable threat to the health of women, cervical carcinoma can be prevented in many cases with adequate screening. The current guidelines for cervical carcinoma screening were created as joint recommendations of the American Cancer Society (ACS, the American Society for Colposcopy and Cervical Pathology (ASCCP and the American Society for Clinical Pathology (ASCP in 2012, and later accepted and promoted by the American Congress of Obstetricians and Gynecologists (ACOG. The 2012 recommendations underscore the utility of molecular testing as an adjunct to cytology screening for certain women and provide guidance to clinicians based on different risk-benefit considerations for different ages. This manuscript will review screening techniques and current recommendations for cervical cancer screening and human papilloma virus (HPV testing, as well as possible future screening strategies.

  7. Electric current model of magnetosphere

    International Nuclear Information System (INIS)

    Alfen, H.

    1979-05-01

    A dualism between the field and the particle approach exists also in plasma physics. A number of phenomena, such as the formation of double layers and the energy transport form one region to another, can be understood only by the particle (electric current) description. Hence a translation of the traditional field description into a particle (electric current) description is essential. Such a translation has earlier been made for the heliosphere. The purpose of this paper is to outline a similar application to the magnetosphere, focussing on the energy transfer from the solar wind. As a first approximation a magnetic field consisting of a dipole field and homogeneous magnetic field is used whereas in a second approximation the configuration is more realistic. (author)

  8. Current trends in nursing theories.

    Science.gov (United States)

    Im, Eun-Ok; Chang, Sun Ju

    2012-06-01

    To explore current trends in nursing theories through an integrated literature review. The literature related to nursing theories during the past 10 years was searched through multiple databases and reviewed to determine themes reflecting current trends in nursing theories. The trends can be categorized into six themes: (a) foci on specifics; (b) coexistence of various types of theories; (c) close links to research; (d) international collaborative works; (e) integration to practice; and (f) selective evolution. We need to make our continuous efforts to link research and practice to theories, to identify specifics of our theories, to develop diverse types of theories, and to conduct international collaborative works. Our paper gives implications for future theoretical development in diverse clinical areas of nursing research and practice. © 2012 Sigma Theta Tau International.

  9. Plasma dynamics in current sheets

    International Nuclear Information System (INIS)

    Bogdanov, S.Yu.; Drejden, G.V.; Kirij, N.P.; AN SSSR, Leningrad

    1992-01-01

    Plasma dynamics in successive stages of current sheet evolution is investigated on the base of analysis of time-spatial variations of electron density and electrodynamic force fields. Current sheet formation is realized in a two-dimensional magnetic field with zero line under the action of relatively small initial disturbances (linear regimes). It is established that in the limits of the formed sheet is concentrated dense (N e ∼= 10 16 cm -3 ) (T i ≥ 100 eV, bar-Z i ≥ 2) hot pressure of which is balanced by the magnetic action of electrodynamic forces is carried out both plasma compression in the sheet limits and the acceleration along the sheet surface from a middle to narrow side edges

  10. Current concepts of severe asthma

    Science.gov (United States)

    Raundhal, Mahesh; Oriss, Timothy B.; Ray, Prabir; Wenzel, Sally E.

    2016-01-01

    The term asthma encompasses a disease spectrum with mild to very severe disease phenotypes whose traditional common characteristic is reversible airflow limitation. Unlike milder disease, severe asthma is poorly controlled by the current standard of care. Ongoing studies using advanced molecular and immunological tools along with improved clinical classification show that severe asthma does not identify a specific patient phenotype, but rather includes patients with constant medical needs, whose pathobiologic and clinical characteristics vary widely. Accordingly, in recent clinical trials, therapies guided by specific patient characteristics have had better outcomes than previous therapies directed to any subject with a diagnosis of severe asthma. However, there are still significant gaps in our understanding of the full scope of this disease that hinder the development of effective treatments for all severe asthmatics. In this Review, we discuss our current state of knowledge regarding severe asthma, highlighting different molecular and immunological pathways that can be targeted for future therapeutic development. PMID:27367183

  11. Quantitative pulsed eddy current analysis

    International Nuclear Information System (INIS)

    Morris, R.A.

    1975-01-01

    The potential of pulsed eddy current testing for furnishing more information than conventional single-frequency eddy current methods has been known for some time. However, a fundamental problem has been analyzing the pulse shape with sufficient precision to produce accurate quantitative results. Accordingly, the primary goal of this investigation was to: demonstrate ways of digitizing the short pulses encountered in PEC testing, and to develop empirical analysis techniques that would predict some of the parameters (e.g., depth) of simple types of defect. This report describes a digitizing technique using a computer and either a conventional nuclear ADC or a fast transient analyzer; the computer software used to collect and analyze pulses; and some of the results obtained. (U.S.)

  12. Nanorobotics current approaches and techniques

    CERN Document Server

    Ferreira, Antoine

    2013-01-01

    Nanorobot devices now perform a wide variety of tasks at the nanoscale in a wide variety of fields including but not limited to fields such as manufacturing, medicine, supply chain, biology, and outer space. Nanorobotics: Current Approaches and Techniques is a comprehensive overview of this interdisciplinary field with a wide ranging discussion that includes nano-manipulation and industrial nanorobotics, nanorobotics in biology and medicine, nanorobotic sensing, navigation and swarm behavior, and protein and DNA-based nanorobotics. Also included is the latest on topics such as bio-nano-actuators and propulsion and navigation of nanorobotic systems using magnetic fields. Nanorobotics: Current Approaches and Techniques is an ideal book for scientists, researchers, and engineers actively involved in applied and robotic research and development.

  13. High resolution eddy current microscopy

    Science.gov (United States)

    Lantz, M. A.; Jarvis, S. P.; Tokumoto, H.

    2001-01-01

    We describe a sensitive scanning force microscope based technique for measuring local variations in resistivity by monitoring changes in the eddy current induced damping of a cantilever with a magnetic tip oscillating above a conducting sample. To achieve a high sensitivity, we used a cantilever with an FeNdBLa particle mounted on the tip. Resistivity measurements are demonstrated on a silicon test structure with a staircase doping profile. Regions with resistivities of 0.0013, 0.0041, and 0.022 Ω cm are clearly resolved with a lateral resolution of approximately 180 nm. For this range of resistivities, the eddy current induced damping is found to depend linearly on the sample resistivity.

  14. Current status of rotavirus vaccines.

    Science.gov (United States)

    Wang, Ching-Min; Chen, Shou-Chien; Chen, Kow-Tong

    2015-11-01

    Rotaviruses remain the major cause of childhood diarrheal disease worldwide and of diarrheal deaths of infants and children in developing countries. The huge burden of childhood rotavirus-related diarrhea in the world continues to drive the remarkable pace of vaccine development. Research articles were searched using terms "rotavirus" and "rotavirus vaccine" in MEDLINE and PubMed. Articles not published in the English language, articles without abstracts, and opinion articles were excluded from the review. After preliminary screening, all articles were reviewed and synthesized to provide an overview of current vaccines and vaccination programs. In this review of the global rotavirus vaccines and vaccination programs, the principles of rotavirus vaccine development and the efficacy of the currently licensed vaccines from both developed and developing countries were summarized. Rotavirus is a common cause of diarrhea in children in both developed and developing countries. Rotavirus vaccination is a cost-effective measure to prevent rotavirus diarrhea.

  15. Current Issues in Maritime Health

    DEFF Research Database (Denmark)

    Wagtmann, Maria Anne

    2008-01-01

     In the early part of 2008, Maria Anne Wagtmann had the opportunity to interview the former president of the International Maritime Health Association, Dr. Tim Carter, in London about a number of current maritime health issues. In this interview, Dr. Tim Carter, who is cur­rently employed...... as the Chief Medical Advisor for the British government's Department for Transport, gives his personal - and thus non-official - opinions on these issues....

  16. Current concepts in maxillofacial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boeddinghaus, Rudolf [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: rboeddinghaus@perthradclinic.com.au; Whyte, Andy [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: awhyte@perthradclinic.com.au

    2008-06-15

    A review of state-of-the-art maxillofacial imaging is presented. Current imaging techniques include intra-oral radiographs, dental panoramic tomography, multidetector helical computed tomography, cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The commonest conditions encountered in clinical radiological practice are reviewed, including maxillofacial deformities, complicated dental impactions, maxillofacial trauma, jaw lesions (cysts, neoplasms, fibro-osseous lesions (FOLs) and infections), and temporomandibular joint pathology. Pre-operative assessment for dental implant placement is also briefly reviewed.

  17. Optical currents in vector fields

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Gorsky, M. P.; Maksimyak, P. P.

    2011-01-01

    The influence of phase relations and the degree of mutual coherence of superimposing waves in the arrangements of twowave superposition on the characteristics of the microparticle's motion has been analyzed. The prospects of studying temporal coherence using the proposed approach are made. For th....... For the first time, we have shown experimentally the possibility of diagnostics the optical currents in liquids caused by polarization characteristics of an optical field alone, using test metallic particles of nanoscale....

  18. Current Directions in Mediation Analysis

    Science.gov (United States)

    MacKinnon, David P.; Fairchild, Amanda J.

    2010-01-01

    Mediating variables continue to play an important role in psychological theory and research. A mediating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables. PMID:20157637

  19. Analysis of current gender stereotypes

    OpenAIRE

    Rosario Castillo-Mayén; Beatriz Montes-Berges

    2014-01-01

    Gender stereotypes are beliefs about attributes associated to women and men that reveal gender discrimination. In order to identify changes of gender discrimination, the study of the stereotypes that prevail nowadays is essential. With this in mind, a scale consisting of 258 stereotypic characteristics was elaborated. This scale comprised two versions, one for female and one for male, which permits the understanding of how each gender is perceived currently. Both versions were filled out by 1...

  20. Social networks user: current research

    OpenAIRE

    Agadullina E.R.

    2015-01-01

    The purpose of this article is to review current research studies focusing on the users of Facebook and their behaviors in social networks. This review is organized into two sections: 1) social-demographic characteristics (Age, Gender, Nationality); 2) personality characteristics (Neuroticism, Extraversion, Openness-to-Experience, Agreeableness, Conscientiousness, Narcissism, Self-esteem). The results showed that the information in the personal profile and online behavior are strongly connect...

  1. [Current therapy of multiple sclerosis].

    Science.gov (United States)

    Antonio García Merino, J

    2014-12-01

    Since the introduction of interferon beta 1 b for the treatment of multiple sclerosis, there has been a progressive increase in the number of drugs available for this disease. Currently, 11 drugs have been approved in Spain, and their indications depend on specific clinical characteristics. The present article reviews these indications and also discusses other medications without official approval that have also been used in multiple sclerosis. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  2. For current viewing resistor loads

    Science.gov (United States)

    Lyons, Gregory R [Tijeras, NM; Hass, Jay B [Lee's Summit, MO

    2011-04-19

    The invention comprises a terminal unit for a flat cable comprising a BNC-PCB connector having a pin for electrically contacting one or more conducting elements of a flat cable, and a current viewing resistor having an opening through which the pin extends and having a resistor face that abuts a connector face of the BNC-PCB connector, wherein the device is a terminal unit for the flat cable.

  3. Current Directions in Mediation Analysis

    OpenAIRE

    MacKinnon, David P.; Fairchild, Amanda J.

    2009-01-01

    Mediating variables continue to play an important role in psychological theory and research. A mediating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables.

  4. High bandwidth beam current monitor

    International Nuclear Information System (INIS)

    Baltrusaitis, R.M.; Ekdahl, C.A.; Cooper, R.G.; Peterson, E.; Warn, C.E.

    1993-01-01

    A stripline directional coupler beam current monitor capable of measuring the time structure of a 30-ps electron beam bunch has been developed. The time response performance of the monitor compares very well with Cherenkov light produced in quartz by the electron beam. The four-pickup monitor is now used on a routine basis for measuring the beam duration, tuning for optimized beam bunching, and centering the bunch in the beam pipe

  5. The WIMP Paradigm: Current Status

    International Nuclear Information System (INIS)

    Feng, Jonathan

    2011-01-01

    The WIMP paradigm is the glue that joins together much of the high energy and cosmic frontiers. It postulates that most of the matter in the Universe is made of weakly-interacting massive particles, with implications for a broad range of experiments and observations. I will review the WIMP paradigm's underlying motivations, its current status in view of rapid experimental progress on several fronts, and recent theoretical variations on the WIMP paradigm theme.

  6. Classification of simple current invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1992-01-01

    We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

  7. [Development of current smallpox vaccines].

    Science.gov (United States)

    Maksiutov, R A; Gavrilova, E V; Shchelkunov, S N

    2011-01-01

    The review gives data on the history of smallpox vaccination and shows the high topicality of designing the current safe vaccines against orthopoxviruses. Four generations of live smallpox, protein subunit, and DNA vaccines are considered. Analysis of the data published leads to the conclusion that it is promising to use the up-to-date generations of safe smallpox subunit or DNA vaccines for mass primary immunization with possible further revaccination with classical live vaccine.

  8. High PRF high current switch

    Science.gov (United States)

    Moran, Stuart L.; Hutcherson, R. Kenneth

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  9. Social networks user: current research

    Directory of Open Access Journals (Sweden)

    Agadullina E.R.

    2015-12-01

    Full Text Available The purpose of this article is to review current research studies focusing on the users of Facebook and their behaviors in social networks. This review is organized into two sections: 1 social-demographic characteristics (Age, Gender, Nationality; 2 personality characteristics (Neuroticism, Extraversion, Openness-to-Experience, Agreeableness, Conscientiousness, Narcissism, Self-esteem. The results showed that the information in the personal profile and online behavior are strongly connected with socio-demographic and personality characteristics

  10. Current Trends in Neonatal Tracheostomy.

    Science.gov (United States)

    Isaiah, Amal; Moyer, Kelly; Pereira, Kevin D

    2016-08-01

    The indications for neonatal tracheostomy may have changed with current noninvasive respiratory therapies compared with previous decades. To study the current trends in neonatal tracheostomy and identify the primary indication for the procedure and risk factors for failed extubation. This retrospective medical record review included 47 neonates who underwent tracheostomy from January 1, 2009, to December 31, 2013, at the University of Maryland Children's Hospital. Group 1 included infants undergoing tracheostomy for the primary indication of upper airway obstruction; group 2, infants with primary pulmonary disease. Data on weight, gestational age, comorbid conditions, congenital abnormalities, complications, outcomes, and indications for tracheostomy were compared statistically between groups. Differences in gestational age, birth weight, and age at tracheostomy. Among the 47 infants included in the study (30 boys; 17 girls, mean [SD] age, 113 [73] days), 31 (66%) demonstrated anatomical causes of airway obstruction, and 16 (34%) had significant pulmonary disease. Among infants with anatomical causes, subglottic stenosis represented the largest group (11 of 31 [35%]). The mean age at the time of tracheostomy was significantly lower in the group with airway obstruction (98.9 vs 146.9 days; difference, 48 [95% CI, 4.8-91.2] days; P = .04). No procedure-related morbidity or mortality was encountered. Anatomical upper airway obstruction may be returning as the most common indication for a neonatal tracheostomy, thereby supporting the belief that current respiratory therapies have lowered the burden of chronic lung disease and the need for prolonged ventilatory care.

  11. Female pattern alopecia: current perspectives

    Directory of Open Access Journals (Sweden)

    Levy LL

    2013-08-01

    Full Text Available Lauren L Levy, Jason J Emer Department of Dermatology, Mount Sinai School of Medicine, New York, NY, USA Abstract: Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification and women exhibiting diffuse hair thinning over the crown (increased part width and sparing of the frontal hairline (Ludwig classification. Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications – minoxidil and finasteride – are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride, prostaglandin analogs (eg, bimatoprost, latanoprost, and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. Keywords: androgenetic alopecia, female pattern hair loss, minoxidil, finasteride, antiandrogens, spironolactone

  12. High current polarized electron source

    Science.gov (United States)

    Suleiman, R.; Adderley, P.; Grames, J.; Hansknecht, J.; Poelker, M.; Stutzman, M.

    2018-05-01

    Jefferson Lab operates two DC high voltage GaAs photoguns with compact inverted insulators. One photogun provides the polarized electron beam at the Continuous Electron Beam Accelerator Facility (CEBAF) up to 200 µA. The other gun is used for high average current photocathode lifetime studies at a dedicated test facility up to 4 mA of polarized beam and 10 mA of un-polarized beam. GaAs-based photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed facilities that must operate in excess of tens of mA of polarized average current. This contribution describes techniques to maintain good vacuum while delivering high beam currents, and techniques that minimize damage due to ion bombardment, the dominant mechanism that reduces photocathode yield. Advantages of higher DC voltage include reduced space-charge emittance growth and the potential for better photocathode lifetime. Highlights of R&D to improve the performance of polarized electron sources and prolong the lifetime of strained-superlattice GaAs are presented.

  13. Management of Current Psychiatric Disorders

    Science.gov (United States)

    Carbonnel, François; David, Michel; Norton, Joanna; Bourrel, Gérard; Boulenger, Jean-Philippe; Capdevielle, Delphine

    2016-01-01

    Objective: Describe and analyse the experience of family physicians in managing current psychiatric disorders to obtain a better understanding of the underlying reasons of under-detection and inadequate prescribing identified in studies. Methods: A qualitative study using in-depth interviews. Sample of 15 practicing family physicians, recruited by telephone from a precedent cohort (Sesame1) with a maximum variation: sex, age, single or group practice, urban or rural. Qualitative method is inspired by the completed grounded theory of a verbatim semiopragmatic analysis from 2 experts in this approach. Results: Family physicians found that current psychiatric disorders were related to psychological symptoms in reaction to life events. Their role was to make patients aware of a psychiatric symptom rather than establish a diagnosis. Their management responsibility was considered in contrasting ways: it was claimed or endured. They defined their position as facilitating compliance to psychiatrist consultations, while assuring a complementary psychotherapeutic approach. Prescribing medication was not a priority for them. Conclusions: The identified under-detection is essentially due to inherent frontline conditions and complexity of clinical forms. The family physician role, facilitating compliance to psychiatrist consultations while assuring a support psychotherapy is the main result of this study. More studies should be conducted to define more accurately the clinical reality, management and course of current psychiatric disorders in primary care.

  14. Baseline restoration using current conveyors

    International Nuclear Information System (INIS)

    Morgado, A.M.L.S.; Simoes, J.B.; Correia, C.M.

    1996-01-01

    A good performance of high resolution nuclear spectrometry systems, at high pulse rates, demands restoration of baseline between pulses, in order to remove rate dependent baseline shifts. This restoration is performed by circuits named baseline restorers (BLRs) which also remove low frequency noise, such as power supply hum and detector microphonics. This paper presents simple circuits for baseline restoration based on a commercial current conveyor (CCII01). Tests were performed, on two circuits, with periodic trapezoidal shaped pulses in order to measure the baseline restoration for several pulse rates and restorer duty cycles. For the current conveyor based Robinson restorer, the peak shift was less than 10 mV, for duty cycles up to 60%, at high pulse rates. Duty cycles up to 80% were also tested, being the maximum peak shift 21 mV. The peak shift for the current conveyor based Grubic restorer was also measured. The maximum value found was 30 mV at 82% duty cycle. Keeping the duty cycle below 60% improves greatly the restorer performance. The ability of both baseline restorer architectures to reject low frequency modulation is also measured, with good results on both circuits

  15. Female pattern alopecia: current perspectives

    Science.gov (United States)

    Levy, Lauren L; Emer, Jason J

    2013-01-01

    Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification) and women exhibiting diffuse hair thinning over the crown (increased part width) and sparing of the frontal hairline (Ludwig classification). Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications – minoxidil and finasteride – are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride), prostaglandin analogs (eg, bimatoprost, latanoprost), and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. PMID:24039457

  16. Electric currents in cosmic plasmas

    International Nuclear Information System (INIS)

    Alfven, H.

    1977-05-01

    Since the beginning of the century physics has been dualistic in the sense that some phenomena are described by a field concept, others by a particle concept. This dualism is essential also in the physics of cosmical plasmas: some phenomena should be described by a magnetic field formalism, others by an electric current formalism. During the first period of evolution of cosmic plasma physics the magnetic field aspect has dominated, and a fairly exhaustive description has been given of those phenomena--like the propagation of waves--which can be described in this way. We have now entered a second period which is dominated by a systematic exploration of the particle (or current) aspect. A survey is given of a number of phenomena which can be understood only from the particle aspect. These include the formation of electric double layers, the origin of explosive events like magnetic substorms and solar flares, and further, the transfer of energy from one region to another. A useful method of exploring many of these phenomena is to draw the electric circuit in which the current flows and study its properties. A number of simple circuits are analyzed in this way. (author)

  17. Current challenges in autonomous driving

    Science.gov (United States)

    Barabás, I.; Todoruţ, A.; Cordoş, N.; Molea, A.

    2017-10-01

    Nowadays the automotive industry makes a quantum shift to a future, where the driver will have smaller and smaller role in driving his or her vehicle ending up being totally excluded. In this paper, we have investigated the different levels of driving automatization, the prospective effects of these new technologies on the environment and traffic safety, the importance of regulations and their current state, the moral aspects of introducing these technologies and the possible scenarios of deploying the autonomous vehicles. We have found that the self-driving technologies are facing many challenges: a) They must make decisions faster in very diverse conditions which can include many moral dilemmas as well; b) They have an important potential in reducing the environmental pollution by optimizing their routes, driving styles by communicating with other vehicles, infrastructures and their environment; c) There is a considerable gap between the self-drive technology level and the current regulations; fortunately, this gap shows a continuously decreasing trend; d) In case of many types of imminent accidents management there are many concerns about the ability of making the right decision. Considering that this field has an extraordinary speed of development, our study is up to date at the submission deadline. Self-driving technologies become increasingly sophisticated and technically accessible, and in some cases, they can be deployed for commercial vehicles as well. According to the current stage of research and development, it is still unclear how the self-driving technologies will be able to handle extreme and unexpected events including their moral aspects. Since most of the traffic accidents are caused by human error or omission, it is expected that the emergence of the autonomous technologies will reduce these accidents in their number and gravity, but the very few currently available test results have not been able to scientifically underpin this issue yet. The

  18. Cryogenic current comparators for precise ion beam current measurements

    International Nuclear Information System (INIS)

    Kurian, Febin

    2015-01-01

    The planned Facility for Antiproton and Ion Research (FAIR) at GSI has to cope with a wide range of beam intensities in its high-energy beam transport systems and in the storage rings. To meet the requirements of a non-intercepting intensity measurement down to nA range, it is planned to install a number of Cryogenic Current Comparator (CCC) units at different locations in the FAIR beamlines. In this work, the first CCC system for intensity measurement of heavy ion beams, which was developed at GSI, was re-commissioned and upgraded to be used as a 'GSI - CCC prototype' for extensive optimization and development of an improved CCC for FAIR. After installation of a new SQUID sensor and related electronics, as well as implementation of improved data acquisition components, successful beam current measurements were performed at a SIS18 extraction line. The measured intensity values were compared with those of a Secondary Electron Monitor (SEM). Furthermore, the spill-structure of a slowly extracted beam was measured and analyzed, investigating its improvement due to bunching during the slow-extraction process. Due to the extreme sensitivity of the superconducting sensor, the determined intensity values as well as the adjustment of the system for optimal performance are strongly influenced by the numerous noise sources of the accelerators environment. For this reason, detailed studies of different effects caused by noise have been carried out, which are presented together with proposals to reduce them. Similarly, studies were performed to increase the dynamic range and overcome slew rate limitations, the results of which are illustrated and discussed as well. By combining the various optimizations and characterizations of the GSI CCC prototype with the experiences made during beam operation, criteria for a more efficient CCC System could be worked out, which are presented in this work. The details of this new design are worked out with respect to the

  19. Internet gaming addiction: current perspectives

    Science.gov (United States)

    Kuss, Daria J

    2013-01-01

    In the 2000s, online games became popular, while studies of Internet gaming addiction emerged, outlining the negative consequences of excessive gaming, its prevalence, and associated risk factors. The establishment of specialized treatment centers in South-East Asia, the US, and Europe reflects the growing need for professional help. It is argued that only by understanding the appeal of Internet gaming, its context, and neurobiologic correlates can the phenomenon of Internet gaming addiction be understood comprehensively. The aim of this review is to provide an insight into current perspectives on Internet gaming addiction using a holistic approach, taking into consideration the mass appeal of online games, the context of Internet gaming addiction, and associated neuroimaging findings, as well as the current diagnostic framework adopted by the American Psychiatric Association. The cited research indicates that the individual’s context is a significant factor that marks the dividing line between excessive gaming and gaming addiction, and the game context can gain particular importance for players, depending on their life situation and gaming preferences. Moreover, the cultural context is significant because it embeds the gamer in a community with shared beliefs and practices, endowing their gaming with particular meaning. The cited neuroimaging studies indicate that Internet gaming addiction shares similarities with other addictions, including substance dependence, at the molecular, neurocircuitry, and behavioral levels. The findings provide support for the current perspective of understanding Internet gaming addiction from a disease framework. The benefits of an Internet gaming addiction diagnosis include reliability across research, destigmatization of individuals, development of efficacious treatments, and the creation of an incentive for public health care and insurance providers. The holistic approach adopted here not only highlights empirical research that

  20. Internet gaming addiction: current perspectives.

    Science.gov (United States)

    Kuss, Daria J

    2013-01-01

    In the 2000s, online games became popular, while studies of Internet gaming addiction emerged, outlining the negative consequences of excessive gaming, its prevalence, and associated risk factors. The establishment of specialized treatment centers in South-East Asia, the US, and Europe reflects the growing need for professional help. It is argued that only by understanding the appeal of Internet gaming, its context, and neurobiologic correlates can the phenomenon of Internet gaming addiction be understood comprehensively. The aim of this review is to provide an insight into current perspectives on Internet gaming addiction using a holistic approach, taking into consideration the mass appeal of online games, the context of Internet gaming addiction, and associated neuroimaging findings, as well as the current diagnostic framework adopted by the American Psychiatric Association. The cited research indicates that the individual's context is a significant factor that marks the dividing line between excessive gaming and gaming addiction, and the game context can gain particular importance for players, depending on their life situation and gaming preferences. Moreover, the cultural context is significant because it embeds the gamer in a community with shared beliefs and practices, endowing their gaming with particular meaning. The cited neuroimaging studies indicate that Internet gaming addiction shares similarities with other addictions, including substance dependence, at the molecular, neurocircuitry, and behavioral levels. The findings provide support for the current perspective of understanding Internet gaming addiction from a disease framework. The benefits of an Internet gaming addiction diagnosis include reliability across research, destigmatization of individuals, development of efficacious treatments, and the creation of an incentive for public health care and insurance providers. The holistic approach adopted here not only highlights empirical research that

  1. Current-Induced Membrane Discharge

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.

    2012-01-01

    . Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H+ ions, and OH- ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal...... neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length...

  2. Current management of hepatocellular carcinoma

    Science.gov (United States)

    Tabrizian, Parissa; Roayaie, Sasan; Schwartz, Myron E

    2014-01-01

    Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and leading cause of death among patients with cirrhosis. Treatment guidelines are based according to the Barcelona Clinic Liver Cancer staging system. The choice among therapeutic options that include liver resection, liver transplantation, locoregional, and systemic treatments must be individualized for each patient. The aim of this paper is to review the outcomes that can be achieved in the treatment of HCC with the heterogeneous therapeutic options currently available in clinical practice. PMID:25132740

  3. DESY: Handling persistent eddy currents

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-04-15

    The vanishing electrical resistance of superconducting coils as well as their ability to provide magnetic fields far beyond those of saturated iron is the main motivation behind the push to use superconducting technology in big new proton accelerators. But this advantage can turn into a drawback at low excitations when the eddy currents - induced in any electromagnet when the field is changed - do not decay, but continue to flow. Preparations for the proton ring of the HERA electron-proton collider nearing completion at the German DESY Laboratory in Hamburg have borne this in mind.

  4. Dark currents for CEBAF linacs

    International Nuclear Information System (INIS)

    Yunn, B.C.

    1995-01-01

    Continuing on our numerical study of field emitted electrons from a superconducting CEBAF cavity we have identified all possible emission sites, magnitudes, and the energy profile of dark currents expected at CEBAF under nominal operating conditions. We find that most electrons do not survive beyond a single cryomodule which includes eight 5-cell superconducting cavities. However, some electrons can be accelerated through many cryomodules, ending up with an energy close to 100 MeV. However, no field emitted electrons can be recirculated along with an electron beam generated at the gun, due to the limited energy acceptance of CEBAF recirculation arcs. 4 refs., 4 figs

  5. Detection of neutral current events

    International Nuclear Information System (INIS)

    Innocenti, P.G.

    1979-01-01

    The topics investigated in the course of the study can be broadly divided into three classes: (i) Inclusive measurements of the scattered electron for the determination of structure functions, scaling violations, deltaL/deltaT and weak interaction effects. (ii) Exclusive measurements of the current jet (momentum, energy, particle composition) for the study of fragmentation functions, for search of new particles, new quarks and QCD effects in the jet. (iii) Search for heavy leptons by detection and identification of their decay products. (orig.)

  6. Internet Addiction: A Current Review

    Directory of Open Access Journals (Sweden)

    Hasan Bozkurt

    2016-09-01

    Full Text Available Internet addiction, which has become a global social issue, can be broadly conceptualized as an inability to control ones use of the Internet which leads to negative consequences in daily life. Only Internet Gaming Disorder has been included in the appendix of the diagnostic and statistical manual of mental disorders fifth edition (DSM-5, but it has already been argued that Internet addiction could also comprise problematic use of other Internet applications developing an addictive behavior. This paper aims to give a current review of the gradually evolving body of literature on Internet addiction. [J Contemp Med 2016; 6(3.000: 235-247

  7. Dark Current Measurements in GIF++

    CERN Document Server

    Al-Qahtani, Abdulaziz

    2017-01-01

    This project revolved around creating a code that treats experiment files in order to fetch dark current measurements done for the Cathode Strip Chambers (CSC) exposed to long-term irradiation at Gamma Irradiation Facility (GIF++) and plot the results as functions of the accumulated charge. This paper will discuss the Compact Muon Solenoid (CMS) experiment, the CSCs that we have looked at (specifically the muon detectors located at the CMS endcaps), longevity test at GIF++, and finally discuss the code and results obtained.

  8. Reconciling current approaches to blindsight

    DEFF Research Database (Denmark)

    Overgaard, Morten; Mogensen, Jesper

    2015-01-01

    After decades of research, blindsight is still a mysterious and controversial topic in consciousness research. Currently, many researchers tend to think of it as an ideal phenomenon to investigate neural correlates of consciousness, whereas others believe that blindsight is in fact a kind...... of degraded vision rather than "truly blind". This article considers both perspectives and finds that both have difficulties understanding all existing evidence about blindsight. In order to reconcile the perspectives, we suggest two specific criteria for a good model of blindsight, able to encompass all...

  9. DESY: Handling persistent eddy currents

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The vanishing electrical resistance of superconducting coils as well as their ability to provide magnetic fields far beyond those of saturated iron is the main motivation behind the push to use superconducting technology in big new proton accelerators. But this advantage can turn into a drawback at low excitations when the eddy currents - induced in any electromagnet when the field is changed - do not decay, but continue to flow. Preparations for the proton ring of the HERA electron-proton collider nearing completion at the German DESY Laboratory in Hamburg have borne this in mind

  10. [Current Treatment of Stable Angina].

    Science.gov (United States)

    Toggweiler, Stefan; Jamshidi, Peiman; Cuculi, Florim

    2015-06-17

    Current therapy for stable angina includes surgical and percutaneous revascularization, which has been improved tremendously over the last decades. Smoking cessation and regular exercise are the cornerstone for prevention of further cerebrovascular events. Medical treatment includes treatment of cardiovascular risk factors and antithrombotic management, which can be a challenge in some patients. Owing to the fact the coronary revascularization is readily accessible these days in many industrialized countries, the importance of antianginal therapy has decreased over the past years. This article presents a contemporary overview of the management of patients with stable angina in the year 2015.

  11. Psychiatry beyond the current paradigm.

    LENUS (Irish Health Repository)

    Bracken, Pat

    2012-12-01

    A series of editorials in this Journal have argued that psychiatry is in the midst of a crisis. The various solutions proposed would all involve a strengthening of psychiatry\\'s identity as essentially \\'applied neuroscience\\'. Although not discounting the importance of the brain sciences and psychopharmacology, we argue that psychiatry needs to move beyond the dominance of the current, technological paradigm. This would be more in keeping with the evidence about how positive outcomes are achieved and could also serve to foster more meaningful collaboration with the growing service user movement.

  12. Power quality issues current harmonics

    CERN Document Server

    Mikkili, Suresh

    2015-01-01

    Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

  13. Markovian representations of current algebras

    International Nuclear Information System (INIS)

    Streater, R.F.

    1977-01-01

    Hegerfeldt's concept (Commun. Math. Phys.; 35:155 (1974)) of T-positivity in Euclidean random fields is generalized to non-commutative probability theory, that is, to Euclidean Fermi fields and to current algebra with possible Schwinger terms. The axioms used imply the Wightman axioms. A non-Abelian form of Markovicity is introduced, and is shown to imply T-positivity if a reflection property holds. The investigation suggests a generalization of Nelson-Symanzik positivity, which might be valid in cases when the extension of the Schwinger functions to coinciding arguments is not expected to maintain both commutativity and positivity (or anti-commutativity and positivity). (author)

  14. Topics in current aerosol research

    CERN Document Server

    Hidy, G M

    1971-01-01

    Topics in Current Aerosol Research deals with the fundamental aspects of aerosol science, with emphasis on experiment and theory describing highly dispersed aerosols (HDAs) as well as the dynamics of charged suspensions. Topics covered range from the basic properties of HDAs to their formation and methods of generation; sources of electric charges; interactions between fluid and aerosol particles; and one-dimensional motion of charged cloud of particles. This volume is comprised of 13 chapters and begins with an introduction to the basic properties of HDAs, followed by a discussion on the form

  15. Internet gaming addiction: current perspectives

    Directory of Open Access Journals (Sweden)

    Kuss DJ

    2013-11-01

    Full Text Available Daria J KussPsychology Research and Behavior Management, Birmingham City University, Birmingham, UKAbstract: In the 2000s, online games became popular, while studies of Internet gaming addiction emerged, outlining the negative consequences of excessive gaming, its prevalence, and associated risk factors. The establishment of specialized treatment centers in South-East Asia, the US, and Europe reflects the growing need for professional help. It is argued that only by understanding the appeal of Internet gaming, its context, and neurobiologic correlates can the phenomenon of Internet gaming addiction be understood comprehensively. The aim of this review is to provide an insight into current perspectives on Internet gaming addiction using a holistic approach, taking into consideration the mass appeal of online games, the context of Internet gaming addiction, and associated neuroimaging findings, as well as the current diagnostic framework adopted by the American Psychiatric Association. The cited research indicates that the individual's context is a significant factor that marks the dividing line between excessive gaming and gaming addiction, and the game context can gain particular importance for players, depending on their life situation and gaming preferences. Moreover, the cultural context is significant because it embeds the gamer in a community with shared beliefs and practices, endowing their gaming with particular meaning. The cited neuroimaging studies indicate that Internet gaming addiction shares similarities with other addictions, including substance dependence, at the molecular, neurocircuitry, and behavioral levels. The findings provide support for the current perspective of understanding Internet gaming addiction from a disease framework. The benefits of an Internet gaming addiction diagnosis include reliability across research, destigmatization of individuals, development of efficacious treatments, and the creation of an incentive

  16. Current algebra; Algebre des courants

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( {delta}I = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [French] La premiere partie de ce cours (trois premiers chapitres), traite des generalites concernant l'algebre de courants. Apres une definition rapide des courants faibles et un rappel de leurs proprietes (hypothese V-A, conservation du courant vecteur, regles de selection, courant axial partiellement conserve,...), l'on introduit l'algebre de Gell-Mann SU (3) x SU (3), et discute les proprietes generales de l'Hamiltonien faible non leptonique. Les chapitres IV a IX sont consacres a des applications importantes de l'algebre des courants. En premier lieu l'on demontre la formule de Adler et Weisberger, par deux methodes differentes, celle dite du repere de moment infini et celle des singularites proches. Cette derniere est seule utilisee dans la suite. Puis, l'on traite successivement les problemes suivants: desintegrations semi-leptoniques des mesons K et des hyperons, theoreme de Kroll-Ruderman, desintegrations non leptoniques des mesons

  17. Current Status of HPV Vaccines

    Science.gov (United States)

    Ma, Barbara; Roden, Richard; Wu, T.C.

    2010-01-01

    Cervical cancer is the second largest cause of cancer deaths in women worldwide, with ~500,000 diagnoses and 274,000 deaths annually. It remains a significant source of morbidity and mortality despite effective screening tools and treatments for its precursor high-grade cervical intraepithelial neoplasia (CIN). Increased understanding of cervical pathogenesis has led to the identification of human papillomavirus (HPV) as the etiological agent for cervical cancer and the development of preventive and therapeutic vaccines targeting HPV antigens for the control of cervical cancer. Herein, we discuss the current status of HPV vaccines. PMID:20677402

  18. Peripartum Cardiomyopathy: A Current Review

    Directory of Open Access Journals (Sweden)

    Katie M. Twomley

    2010-01-01

    Full Text Available Peripartum cardiomyopathy (PPCM is a rare but potentially lethal complication of pregnancy occurring in approximately 1 : 3,000 live births in the United States although some series report a much higher incidence. African-American women are particularly at risk. Diagnosis requires symptoms of heart failure in the last month of pregnancy or within five months of delivery in the absence of recognized cardiac disease prior to pregnancy as well as objective evidence of left ventricular systolic dysfunction. This paper provides an updated, comprehensive review of PPCM, including emerging insights into the etiology of this disorder as well as current treatment options.

  19. Dark Matter Detection: Current Status

    International Nuclear Information System (INIS)

    Akerib, Daniel S.

    2011-01-01

    Overwhelming observational evidence indicates that most of the matter in the Universe consists of non-baryonic dark matter. One possibility is that the dark matter is Weakly-Interacting Massive Particles (WIMPs) that were produced in the early Universe. These relics could comprise the Milky Way's dark halo and provide evidence for new particle physics, such as Supersymmetry. This talk focuses on the status of current efforts to detect dark matter by testing the hypothesis that WIMPs exist in the galactic halo. WIMP searches have begun to explore the region of parameter space where SUSY particles could provide dark matter candidates.

  20. High Critical Current Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, M. P.; Selvamanickam, V. (SuperPower, Inc.)

    2011-12-27

    One of the important critical needs that came out of the DOE’s coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.

  1. Analysis of current gender stereotypes

    Directory of Open Access Journals (Sweden)

    Rosario Castillo-Mayén

    2014-10-01

    Full Text Available Gender stereotypes are beliefs about attributes associated to women and men that reveal gender discrimination. In order to identify changes of gender discrimination, the study of the stereotypes that prevail nowadays is essential. With this in mind, a scale consisting of 258 stereotypic characteristics was elaborated. This scale comprised two versions, one for female and one for male, which permits the understanding of how each gender is perceived currently. Both versions were filled out by 164 undergraduates (50% women. Taking into account those stereotypes that are still differentially assigned to each gender, this study identifies current gender stereotypes that are independent of sociodemographic characteristics, such as age or sex. In addition, new gender stereotypes emerged recently were gathered, and important changes of stereotypes were emphasized, especially those of feminine stereotypes. According to social role theory, these changes are the consequence of social roles changes. Conclusions highlight that, although part of the results involve progress on the achievement of equality, traditional stereotypic characteristics are still referred to each gender, which perpetuate discrimination.

  2. Botrytized wines – current perspectives

    Directory of Open Access Journals (Sweden)

    Magyar I

    2016-10-01

    Full Text Available Ildikó Magyar, János Soós Department of Oenology, Institute of Viticulture and Oenology, Szent István University, Budapest, Hungary Abstract: Botrytized wines are wine specialties made of overripe grapes infected by Botrytis cinerea with the form “noble rot”. Due to the particular characteristics of the noble rotted grape, these wines (eg, Tokaji Aszú, Sauternes, Trockenbeerenauslese types, etc have many characteristic features, including higher or lower residual sugar content and unique aroma composition. The technology, biochemistry, and special characteristics of botrytized wines have been researched for a long time. This review outlines the main directions of the current studies, giving a brief overview on the recent findings. Beside the traditional wine types, noble rot is increasingly utilized in making newer sweet wine styles and straw (passito wines, which generates a series of new interesting experimental results. The fungus–grape interactions during the noble rot, the induced botrytization, the microbial communities of botrytized wines, and the volatile compounds having key roles in the distinct aroma of these wine styles are being focused on in the current studies in this field. Keywords: Botrytis, noble rot, sweet wines, passito wine, aroma

  3. Current puzzles in nuclear physics

    International Nuclear Information System (INIS)

    1985-01-01

    A meeting on ''Current puzzles in nuclear physics'' was held at Research Center for Nuclear Physics, Osaka University, on June 27 - 28, 1984. The meeting put emphasis on several puzzles which have not been solved for a long time in nuclear physics, and also on the puzzles. This collective report is composed of following eleven papers presented at the meeting. Almost all the papers are witten in English : (1) M1, GT excitations and configuration mixing (in Japanese). (2) Hadronic excitation of pionic states. (3) Microscopic analyses of 28 Si(α,α') 28 Si scattering and single particle strength in A = 29 nuclei. (4) Few-body physics and its incentives to nuclear physics. (5) Is it necessary to introduce three body interactions ? (in Japanese). (6) Puzzles in the neutron-deuteron elastic scattering. (7) Puzzles in NN, NΔ, πN and Nanti N interactions. (8) Problems in Hadron-Nucleus interaction. (9) Unified approach to the meson- and quark- theory of nuclear forces and currents. (10) Pion photoproduction in two Chiral bag models. (11) The dynamic bag model : The electromagnetic properties of nucleon. (Aoki, K.)

  4. HIV: current opinion in escapology.

    Science.gov (United States)

    Klenerman, Paul; Wu, Ying; Phillips, Rodney

    2002-08-01

    Much recent work strongly supports the hypothesis that CD8(+) T lymphocytes (CTLs) exert important immune control over HIV and so are a major selective force in its evolution. We analyse this host-pathogen interplay and focus on new data that describe the overall 'effectiveness' of CTL responses (strength, spread, specificity and 'stamina') and the mechanisms by which HIV may evade this suppressive activity. CTLs directed against HIV recognise very large numbers of distinct epitopes across the genome, are largely functional, turn over rapidly, and possess a phenotype that is distinct from CD8(+) lymphocytes specific for other viruses. Mutation of HIV epitopes that alters or abolishes CTL recognition altogether appears to be the most important immune escape mechanism, as the variation that HIV generates defies the limits of the T cell repertoire. However, this immune evasion is still only well-studied in a few patients. The rules that govern immune escape, and the ultimate limits of CTL capacity to deal with the variant epitopes that currently circulate, are not understood. This information will determine the feasibility of current vaccine approaches that, so far, make no provision for the enormous antigenic plasticity of HIV.

  5. Current thinking on genital herpes.

    Science.gov (United States)

    Hofstetter, Annika M; Rosenthal, Susan L; Stanberry, Lawrence R

    2014-02-01

    Genital herpes has a high global prevalence and burden of disease. This manuscript highlights recent advances in our understanding of genital herpes simplex virus (HSV) infections. Studies demonstrate a changing epidemiological landscape with an increasing proportion of genital herpes cases associated with HSV type 1. There is also growing evidence that the majority of infected individuals exhibit frequent, brief shedding episodes that are most often asymptomatic, which likely contribute to high HSV transmission rates. Given this finding as well as readily available serological assays, some have proposed that routine HSV screening be performed; however, this remains controversial and is not currently recommended. Host immune responses, particularly local CD4 and CD8 T cell activity, are crucial for HSV control and clearance following initial infection, during latency and after reactivation. Prior HSV immunity may also afford partial protection against HSV reinfection and disease. Although HSV vaccine trials have been disappointing to date and existing antiviral medications are limited, novel prophylactic and therapeutic modalities are currently in development. Although much remains unknown about genital herpes, improved knowledge of HSV epidemiology, pathogenesis and host immunity may help guide new strategies for disease prevention and control.

  6. Current procedural terminology; a primer.

    Science.gov (United States)

    Hirsch, Joshua A; Leslie-Mazwi, Thabele M; Nicola, Gregory N; Barr, Robert M; Bello, Jacqueline A; Donovan, William D; Tu, Raymond; Alson, Mark D; Manchikanti, Laxmaiah

    2015-04-01

    In 1966, The American Medical Association (AMA) working with multiple major medical specialty societies developed an iterative coding system for describing medical procedures and services using uniform language, the Current Procedural Terminology (CPT) system. The current code set, CPT IV, forms the basis of reporting most of the services performed by healthcare providers, physicians and non-physicians as well as facilities allowing effective, reliable communication among physician and other providers, third parties and patients. This coding system and its maintenance has evolved significantly since its inception, and now goes well beyond its readily perceived role in reimbursement. Additional roles include administrative management, tracking new and investigational procedures, and evolving aspects of 'pay for performance'. The system also allows for local, regional and national utilization comparisons for medical education and research. Neurointerventional specialists use CPT category I codes regularly--for example, 36,215 for first-order cerebrovascular angiography, 36,216 for second-order vessels, and 37,184 for acute stroke treatment by mechanical means. Additionally, physicians add relevant modifiers to the CPT codes, such as '-26' to indicate 'professional charge only,' or '-59' to indicate a distinct procedural service performed on the same day. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Flexible eddy current coil arrays

    International Nuclear Information System (INIS)

    Krampfner, Y.; Johnson, D.P.

    1987-01-01

    A novel approach was devised to overcome certain limitations of conventional eddy current testing. The typical single-element hand-wound probe was replaced with a two dimensional array of spirally wound probe elements deposited on a thin, flexible polyimide substrate. This provides full and reliable coverage of the test area and eliminates the need for scanning. The flexible substrate construction of the array allows the probes to conform to irregular part geometries, such as turbine blades and tubing, thereby eliminating the need for specialized probes for each geometry. Additionally, the batch manufacturing process of the array can yield highly uniform and reproducible coil geometries. The array is driven by a portable computer-based eddy current instrument, smartEDDY/sup TM/, capable of two-frequency operation, and offers a great deal of versatility and flexibility due to its software-based architecture. The array is coupled to the instrument via an 80-switch multiplexer that can be configured to address up to 1600 probes. The individual array elements may be addressed in any desired sequence, as defined by the software

  8. Gargamelle and the neutral currents

    International Nuclear Information System (INIS)

    Rousset, A.

    1996-06-01

    In order to simplify the description of forces, the physicists want to reduce the number of four interactions to a smaller one. They want to unify them. Einstein tried to unify the electromagnetic interaction and the gravitation interaction but it was probably the most difficult to unify. during the sixties, the American physicists Sheldon Glashow and Steven Weinberg and the Pakistani Abdus Salam ( each rewarded by the Nobel price of 1979) propose to unify the weak and electromagnetic interactions interactions under the form of an only interaction, the electro-weak interaction. To check the validity of this theory exist the demonstration by the weak neutral currents. In 1973, European physicians which analyzed photos taken in the bubble chamber called Gargamelle brought the experimental proof. This book tells the story of this discovery. (N.C.)

  9. Conformable eddy current array delivery

    Science.gov (United States)

    Summan, Rahul; Pierce, Gareth; Macleod, Charles; Mineo, Carmelo; Riise, Jonathan; Morozov, Maxim; Dobie, Gordon; Bolton, Gary; Raude, Angélique; Dalpé, Colombe; Braumann, Johannes

    2016-02-01

    The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path was designed using the KUKA|PRC path planning software. Custom software was then written to interface measurement acquisition from the Eddyfi hardware with the motion control of the robot. Preliminary results and analysis are presented from scanning two canisters.

  10. Current Mysteries of AGB Stars

    Science.gov (United States)

    Tout, Christopher A.

    We pay tribute to the memory of Manuel Forestini by recalling his contributions to astronomy and in particular to our understanding of AGB stars. We critically examine the current status of this understanding amongst the community and deduce that major uncertainties arise in the physics of convection, any form of extra mixing beyond convection and the mass loss from the stellar surface. Coupled with these are numerical difficulties associated with the short and similar timescales for structural changes, nuclear burning and convective mixing. We hope that workshops such as this will promote familiarity amongst our diverse international community young and old and so promote effective dialogue that will ultimately lead to solutions to our problems along with the creation of new ones for the future!

  11. Current trends in plant breeding

    International Nuclear Information System (INIS)

    Jalani, B.S.; Rajanaidu, N.

    2000-01-01

    The current world population is 6 billion and it is likely to reach 7 billion in 2010 and 8 billion 2025. Sufficient food must be produced for the ever increasing human population. The available suitable land for intensive agriculture is limited. We have to produce more food from less land, pesticide, labour and water resources. Hence, increase in crop productivity are essential to feed the world in the next century. Plant breeding provides the avenue to increase the food production to feed the growing world population. Development of a cultivar involves (I) Construction of a genetic model (II) creating a gene pool (III) selection among plants and (IV) testing the selected genotypes for adaptation to the biotic and abiotic environments (Frey, 1999). This paper discusses the trends in plant breeding using the oil palm as a model. It covers (i) genetic resources (ii) physiological traits (III) exploitation of genotype x environment interaction (IV) oil palm clones, and (v) biotechnology application. (Author)

  12. Electroconvulsive Therapy: A Current Review

    Directory of Open Access Journals (Sweden)

    Gokben Hizli Sayar

    2014-06-01

    Full Text Available Most of the electroconvulsive therapy guidelines state that severe major depression with psychotic features, manic delirium, or catatonia are conditions where there is a clear consensus favoring early electroconvulsive therapy. The decision to administer electroconvulsive therapy is based on an evaluation of the risks and benefits for the individual patient and involves a combination of factors, including psychiatric diagnosis, type and severity of symptoms, prior treatment history and response, identification of possible alternative treatment options, and consumer preference. In this review history, mechanisms of action, side effects that have been referenced in the literature and clinical experience are discussed. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(2.000: 107-125

  13. Engineered barriers: current status 1989

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.B.

    1989-06-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain substantially the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide a measure of containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  14. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  15. [Current description of multiple sclerosis].

    Science.gov (United States)

    Río, Jordi; Montalbán, Xavier

    2014-12-01

    Multiple sclerosis is a multifocal demyelinating disease leading to progressive neurodegeneration caused by an autoimmune response in genetically predisposed individuals. In the last few years, the knowledge and management of this disease has been revolutionized by a series of findings. The present article reviews pathological features of the disease, in which cortical involvement is increasingly implicated, and aspects related to novel pathogenic mechanisms, such as the role of the microbiota in the genesis of multiple sclerosis, as well as recent contributions from the fields of epidemiology and genetics. Also reviewed are the latest diagnostic criteria, which currently allow a much earlier diagnosis, with clear therapeutic implications. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  16. CURRENT CONCEPTS IN ACL RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Freddie H. Fu

    2008-09-01

    Full Text Available Current Concepts in ACL Reconstruction is a complete reference text composed of the most thorough collection of topics on the ACL and its surgical reconstruction compiled, with contributions from some of the world's experts and most experienced ACL surgeons. Various procedures mentioned throughout the text are also demonstrated in an accompanying video CD-ROM. PURPOSE Composing a single, comprehensive and complete information source on ACL including basic sciences, clinical issues, latest concepts and surgical techniques, from evaluation to outcome, from history to future, editors and contributors have targeted to keep the audience pace with the latest concepts and techniques for the evaluation and the treatment of ACL injuries. FEATURES The text is composed of 27 chapters in 6 sections. The first section is mostly about basic sciences, also history of the ACL, imaging, clinical approach to adolescent and pediatric patients are subjected. In the second section, Graft Choices and Arthroscopy Portals for ACL Reconstruction are mentioned. The third section is about the technique and the outcome of the single-bundle ACL reconstruction. The fourth chapter includes the techniques and outcome of the double-bundle ACL reconstruction. In the fifth chapter revision, navigation technology, rehabilitation and the evaluation of the outcome of ACL reconstruction is subjected. The sixth/the last chapter is about the future advances to reach: What We Have Learned and the Future of ACL Reconstruction. AUDIENCE Orthopedic residents, sports traumatology and knee surgery fellows, orthopedic surgeons, also scientists in basic sciences or clinicians who are studying or planning a research on ACL forms the audience group of this book. ASSESSMENT This is the latest, the most complete and comprehensive textbook of ACL reconstruction produced by the editorial work up of two pioneer and masters "Freddie H. Fu MD and Steven B. Cohen MD" with the contribution of world

  17. Current puzzles and future possibilities

    International Nuclear Information System (INIS)

    Nagamiya, S.

    1982-02-01

    Four current puzzles and several future experimental possibilities in high-energy nuclear collision research are discussed. These puzzles are (1) entropy, (2) hydrodynamic flow, (3) anomalon, and (4) particle emission at backward angles in proton-nucleus collisions. The last one seems not to be directly related to the subject of the present school. But it is, because particle emission into the region far beyond the nucleon-nucleon kinematical limit is an interesting subject common for both proton-nucleus and nucleus-nucleus collisions, and the basic mechanism involved is strongly related in these two cases. Future experimental possibilities are described which include: (1) possibilities of studying multibaryonic excited states, (2) applications of neutron-rich isotopes, and (3) other needed experimental tasks. 72 references

  18. [Current management of thalassemia intermedia].

    Science.gov (United States)

    Thuret, I

    2014-11-01

    Thalassemia intermedia is a clinical entity where anemia is mild or moderate, requiring no or occasional transfusion. Non-transfusion-dependent thalassemia encompasses 3 main clinical forms: beta-thalassemia intermedia, hemoglobin E/beta-thalassemia and alpha-thalassemia intermedia (HbH disease). Clinical severity of thalassemia intermedia increases with age, with more severe anemia and more frequent complications such as extramedullary hematopoiesis and iron overload mainly related to increased intestinal absorption. Numerous adverse events including pulmonary hypertension and hypercoagulability have been associated with splenectomy, often performed in thalassemia intermedia patients. The potential preventive benefit of transfusion and chelation therapies on the occurrence of numerous complications supports the strategy of an earlier therapeutic intervention. Increasing knowledge about pathophysiological mechanisms involved in thalassemia erythropoiesis and related iron overload is currently translating in novel therapeutic approaches. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. High current capacity electrical connector

    International Nuclear Information System (INIS)

    Bettis, E.S.; Watts, H.L.

    1976-01-01

    An electrical connector is provided for coupling high current capacity electrical conductors such as copper busses or the like. The connector is arranged in a ''sandwiched'' configuration in which a conductor plate contacts the busses along major surfaces clamped between two stainless steel backing plates. The conductor plate is provided with contact buttons in a spaced array such that the caps of the buttons extend above the conductor plate surface to contact the busses. When clamping bolts provided through openings in the sandwiched arrangement are tightened, Belleville springs provided under the rim of each button cap are compressed and resiliently force the caps into contact with the busses' contacting surfaces to maintain a predetermined electrical contact area provided by the button cap tops. The contact area does not change with changing thermal or mechanical stresses applied to the coupled conductors

  20. [The current role of warfarin].

    Science.gov (United States)

    Michalcová, Jana; Buliková, Alena; Zavřelová, Jiřina; Prudková, Marie; Penka, Miroslav

    Well-managed warfarin therapy remains an important method of anticoagulation in the 21st century, despite the introduction of new antithrombotics into the clinical practice. The main advantages of warfarin are decades of treatment experience, the possibility to monitor its anticoagulant effect using the INR and the last, but not least, the low cost. Currently, approximately 75 % of anticoagulated patients in the Czech Republic are treated with warfarin and warfarin remains the only option for oral anticoagulant therapy in certain clinical conditions (particularly in patients with valvular atrial fibrillation or mechanical heart valves). For physicians across specialties it is still indispensable to master the basics of safe and effective warfarin therapy, including the management of treatment complications.Key words: anticoagulant therapy - INR - thrombosis - warfarin.

  1. Current instability of `Snow Plough`

    Energy Technology Data Exchange (ETDEWEB)

    Rudakov, L I; Sevastianov, A A [Kurchatov Institute, Moscow (Russian Federation)

    1997-12-31

    The analysis of data obtained in experiments on liner implosion at the large thermonuclear installations as Module-A5, Saturn, and Angara-5 show substantial discrepancy with the supposed Rayleigh-Taylor scenario of the liner shell disruption. Apparently there must be an alternative scenario which gives rise to the fall-through of the current into the internal regions of the liner, determining thus future behaviour of mass. Moreover, exact correlation between the process of stratification and occurrence of the lighting kernel in the region near the axis have been observed in the Modul-5 installation. A new two-fluid theoretical MHD model is described in the paper, which can well explain all the phases of the liner evolution observed in real experiments. (J.U.). 1 fig., 3 refs.

  2. Current knowledge on pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Juan eIovanna

    2012-01-01

    Full Text Available Pancreatic cancer is the fourth leading cause of cancer death with a median survival of 6 months and a dismal 5-year survival rate of 3-5%. The development and progression of pancreatic cancer are caused by the activation of oncogenes, the inactivation of tumor suppressor genes and the deregulation of many signalling pathways. Therefore, the strategies targeting these molecules as well as their downstream signalling could be promising for the prevention and treatment of pancreatic cancer. However, although targeted therapies for pancreatic cancer have yielded encouraging results in vitro and in animal models, these findings have not been translated into improved outcomes in clinical trials. This failure is due to an incomplete understanding of the biology of pancreatic cancer and to the selection of poorly efficient or imperfectly targeted agents. In this review, we will critically present the current knowledge regarding the molecular, biochemical, clinical and therapeutic aspects of pancreatic cancer.

  3. Current Knowledge on Pancreatic Cancer

    International Nuclear Information System (INIS)

    Iovanna, Juan; Mallmann, Maria Cecilia; Gonçalves, Anthony; Turrini, Olivier; Dagorn, Jean-Charles

    2012-01-01

    Pancreatic cancer is the fourth leading cause of cancer death with a median survival of 6 months and a dismal 5-year survival rate of 3–5%. The development and progression of pancreatic cancer are caused by the activation of oncogenes, the inactivation of tumor suppressor genes, and the deregulation of many signaling pathways. Therefore, the strategies targeting these molecules as well as their downstream signaling could be promising for the prevention and treatment of pancreatic cancer. However, although targeted therapies for pancreatic cancer have yielded encouraging results in vitro and in animal models, these findings have not been translated into improved outcomes in clinical trials. This failure is due to an incomplete understanding of the biology of pancreatic cancer and to the selection of poorly efficient or imperfectly targeted agents. In this review, we will critically present the current knowledge regarding the molecular, biochemical, clinical, and therapeutic aspects of pancreatic cancer.

  4. Current Knowledge on Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Iovanna, Juan [INSERM U624, Stress Cellulaire, Parc Scientifique et Technologique de Luminy, Marseille (France); Mallmann, Maria Cecilia [Centre d’Investigation Clinique de Marseille, Marseille (France); Gonçalves, Anthony [Département d’Oncologie Médicale, Institut Paoli-Calmettes, Marseille (France); Turrini, Olivier [Département de Chirurgie Oncologique, Institut Paoli-Calmettes, Marseille (France); Dagorn, Jean-Charles, E-mail: juan.iovanna@inserm.fr [INSERM U624, Stress Cellulaire, Parc Scientifique et Technologique de Luminy, Marseille (France)

    2012-01-31

    Pancreatic cancer is the fourth leading cause of cancer death with a median survival of 6 months and a dismal 5-year survival rate of 3–5%. The development and progression of pancreatic cancer are caused by the activation of oncogenes, the inactivation of tumor suppressor genes, and the deregulation of many signaling pathways. Therefore, the strategies targeting these molecules as well as their downstream signaling could be promising for the prevention and treatment of pancreatic cancer. However, although targeted therapies for pancreatic cancer have yielded encouraging results in vitro and in animal models, these findings have not been translated into improved outcomes in clinical trials. This failure is due to an incomplete understanding of the biology of pancreatic cancer and to the selection of poorly efficient or imperfectly targeted agents. In this review, we will critically present the current knowledge regarding the molecular, biochemical, clinical, and therapeutic aspects of pancreatic cancer.

  5. Coronary MR angiography: current status

    International Nuclear Information System (INIS)

    Danias, P.G.; Manning, W.J.

    2000-01-01

    Since first described in the early 1990s, coronary magnetic resonance angiography (MRA) has evolved as a promising noninvasive modality for imaging of the coronary arteries and evaluation of coronary artery disease. Despite technical limitations, coronary MRA has established value for imaging of anomalous coronary arteries and assessment of bypass graft patency. Current research focuses on the development of optimal respiratory compensation strategies, improved spatial and temporal resolution and faster acquisition of image data. The accurate detection of stenoses and assessment of the severity of coronary atherosclerosis is presently being evaluated with large multi-center studies. With further technique enhancements and more clinical experience, coronary MRA is likely to become the dominant noninvasive modality in clinical cardiology. (orig.) [de

  6. Low current approach to ignition

    International Nuclear Information System (INIS)

    Cenacchi, G.; Sugiyama, L.; Airoldi, A.; Coppi, B.

    1996-01-01

    The open-quotes standardclose quotes path to achieve ignition conditions so far has been that of producing plasmas with the maximum current and poloidal field that axe compatible with the applied toroidal field and the geometry of the adopted configuration (the low q a approach.) The other approach is that motivated by recent experiments with reversed shear configurations, with relatively low currents and high fields corresponding to high values of q a (e-g., q a ≅ 6). While the first approach can be pursued with ohmic heating alone, the second one necessarily involves an auxiliary heating system. One of the advantages of this approach is that the onset of large scale internal modes can be avoided as q(ψ) is kept above 1 over the entire plasma column. Since quite peaked density profiles are produced in the regimes where enhanced confinement is observed, the α-particle power levels for which ignition can be reached and therefore the thermal wall loading on the first wall, can be reduced relatively to the standard, low q a , approach. The possibility is considered that ignition is reached in the reversed shear, high q a , regime and that this is followed by a transition to non-reversed profiles, or even the low q a regime, assuming that the excitation of modes involving magnetic reconnection will not undermine the needed degree of confinement. These results have been demonstrated by numerical transport simulation for the Ignitor-Ult machine, but are applicable to all high field ignition experiments

  7. High current superconductors for DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzone, Pierluigi, E-mail: pierluigi.bruzzone@psi.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association Euratom – Confédération Suisse, CH-5232 Villigen PSI (Switzerland); Sedlak, Kamil; Stepanov, Boris [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association Euratom – Confédération Suisse, CH-5232 Villigen PSI (Switzerland)

    2013-10-15

    Highlights: ► Definition of requirement for TF coil based on the input of system code. ► A TF coil and conductor design for the European DEMO project. ► Use of React and Wind method opposite to Wind and React with related advantages. ► Hybridization of winding pack, Nb/Nb{sub 3}Sn, by graded layer winding. -- Abstract: In the assumption that DEMO will be an inductively driven tokamak, the number of load cycles will be in the range of several hundred thousands. The requirements for a new generation of Nb{sub 3}Sn based high current conductors for DEMO are drafted starting from the output of system code PROCESS. The key objectives include the stability of the DC performance over the lifetime of the machine and the effective use of the Nb{sub 3}Sn strand properties, for cost and reliability reasons. A preliminary layout of the winding pack and conductors for the toroidal field magnets is presented. To suppress the mechanism of reversible and irreversible degradation, i.e. to preserve in the cabled conductor the high critical current density of the strand, the thermal strain must be insignificant and no space for micro-bending under transverse load must be left in the strand bundle. The “react-and-wind” method is preferred here, with a graded, layer wound magnet, containing both Nb{sub 3}Sn and NbTi layers. The implications of the conductor choice on the coil design and technology are highlighted. A roadmap is sketched for the development of a full size prototype conductor sample and demonstration of the key technologies.

  8. Current treatments for radiation retinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Giuliari, Gian Paolo; Simpson, E. Rand (Princess Margaret Hospital, Univ. of Toronto, Dept. of Ophthalmology and Vision Sciences, Toronto (Canada)), e-mail: gpgiuliari@gmail.com; Sadaka, Ama (Schepens Eye Research Inst., Boston, MA (United States)); Hinkle, David M. (Massachusetts Eye Research and Surgery Institution, Cambridge, MA (United States))

    2011-01-15

    Background. To review the currently available therapeutic modalities for radiation retinopathy (RR), including newer investigational interventions directed towards specific aspects of the pathophysiology of this refractory complication. Methods. A review of the literature encompassing the pathogenesis of RR and the current therapeutic modalities available was performed. Results. RR is a chronic and progressive condition that results from exposure to any source of radiation. It might be secondary to radiation treatment of intraocular tumors such as choroidal melanomas, retinoblastomas, and choroidal metastasis, or from unavoidable exposure to excessive radiation from the treatment of extraocular tumors like cephalic, nasopharyngeal, orbital, and paranasal malignancies. After the results of the Collaborative Ocular Melanoma Study, most of the choroidal melanomas are being treated with plaque brachytherapy increasing by that the incidence of this radiation complication. RR has been reported to occur in as many as 60% of eyes treated with plaque radiation, with higher rates associated with larger tumors. Initially, the condition manifests as a radiation vasculopathy clinically seen as microaneurysms and telangiectasis, with posterior development of retinal hard exudates and hemorrhages, macular edema, neovascularization and tractional retinal detachment. Regrettably, the management of these eyes remains limited. Photodynamic therapy, laser photocoagulation, oral pentoxyphylline and hyperbaric oxygen have been attempted as treatment modalities with inconclusive results. Intravitreal injections of anti-vascular endothelial growth factor such as bevacizumab, ranibizumab and pegaptanib sodium have been recently used, also with variable results. Discussion. RR is a common vision threatening complication following radiation therapy. The available therapeutic options are limited and show unsatisfactory results. Further large investigative studies are required for developing

  9. Current Migration Movements in Europe

    Directory of Open Access Journals (Sweden)

    Jelena Zlatković Winter

    2004-09-01

    Full Text Available After a brief historical review of migrations in Europe, the paper focuses on current migration trends and their consequences. At the end of the 1950s, Western Europe began to recruit labour from several Mediterranean countries – Italy, Spain, Portugal and former Yugoslavia, and later from Morocco, Algeria, Tunisia and Turkey. Some countries, such as France, Great Britain and the Netherlands, recruited also workers from their former colonies. In 1970 Germany had the highest absolute number of foreigners, followed by France, and then Switzerland and Belgium. The total number of immigrants in Western Europe was twelve million. During the 1970s mass recruitment of foreign workers was abandoned, and only the arrival of their family members was permitted, which led to family reunification in the countries of employment. Europe closed its borders, with the result that clandestine migration increased. The year 1989 was a turning point in the history of international migrations. The political changes in Central and Eastern Europe brought about mass migration to the West, which culminated in the so-called “mass movement of 1989–1990”. The arrival of ethnic Germans in Germany, migration inside and outside of the territory of the former Soviet Union, an increase in the number of asylum seekers and displaced persons, due to armed conflicts, are – according to the author – the main traits of current migration. The main part of the paper discusses the causes and effects of this mass wave, as well as trends in labour migration, which is still present. The second part of the paper, after presenting a typology of migrations, deals with the complex processes that brought about the formation of new communities and led to the phenomenon of new ethnic minorities and to corresponding migration policies in Western European countries that had to address these issues.

  10. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The background resonance Δ(1230), Nsup(*)(1520), Nsup(*)(1470) and Nsup(*)(1535)pion and axial-vector amplitudes are first calculated in the soft pion and on-shell configuration, respectively. Then a comparison is made with the usual soft pion theorems and on-shell low-energy expansions of current algebra as worked out in the previous paper. The agreement is good and we also deduce a nucleon dipole form factor axial-vector mass of msub(A)approximately equal to 1,23 GeV. Finally an approximate value for the non-strange current quark mass of m equal to 0,64 +- 1,11μ is extracted from the data

  11. Excessive current in wide superconducting films

    International Nuclear Information System (INIS)

    Volotskaya, V.G.; Sivakov, A.G.; Turutanov, O.G.

    1986-01-01

    The resistive state of a wide long film due to superconductivity destruction by current is studied. The voltage-independent excess current I 0 is observed on I-V curves at high transport currents. The two-dimensional image of the current-carrying sample obtained by laser scanning technique in this current range indicates that the whole film is in the resistive state. The current I 0 is measured as a function of magnetic field and SHF power

  12. Current Challenges in Cancer Treatment.

    Science.gov (United States)

    Zugazagoitia, Jon; Guedes, Cristiano; Ponce, Santiago; Ferrer, Irene; Molina-Pinelo, Sonia; Paz-Ares, Luis

    2016-07-01

    In this review, we highlight the current concepts and discuss some of the current challenges and future prospects in cancer therapy. We frequently use the example of lung cancer. We conducted a nonsystematic PubMed search, selecting the most comprehensive and relevant research articles, clinical trials, translational papers, and review articles on precision oncology and immuno-oncology. Papers were prioritized and selected based on their originality and potential clinical applicability. Two major revolutions have changed cancer treatment paradigms in the past few years: targeting actionable alterations in oncogene-driven cancers and immuno-oncology. Important challenges are still ongoing in both fields of cancer therapy. On the one hand, druggable genomic alterations are diverse and represent only small subsets of patients in certain tumor types, which limits testing their clinical impact in biomarker-driven clinical trials. Next-generation sequencing technologies are increasingly being implemented for molecular prescreening in clinical research, but issues regarding clinical interpretation of large genomic data make their wide clinical use difficult. Further, dealing with tumor heterogeneity and acquired resistance is probably the main limitation for the success of precision oncology. On the other hand, long-term survival benefits with immune checkpoint inhibitors (anti-programmed death cell protein-1/programmed death cell ligand-1[PD-1/L1] and anti-cytotoxic T lymphocyte antigen-4 monoclonal antibodies) are restricted to a minority of patients, and no predictive markers are yet robustly validated that could help us recognize these subsets and optimize treatment delivery and selection. To achieve long-term survival benefits, drug combinations targeting several molecular alterations or cancer hallmarks might be needed. This will probably be one of the most challenging but promising precision cancer treatment strategies in the future. Targeting single molecular

  13. Current approach to liver traumas.

    Science.gov (United States)

    Kaptanoglu, Levent; Kurt, Necmi; Sikar, Hasan Ediz

    2017-03-01

    Liver injuries remain major obstacle for successful treatment, due to size and location of the liver. Requirement for surgery should be determined by clinical factors, most notably hemodynamical state. In this present study we tried to declare our approach to liver traumas. We also tried to emphasize the importance of conservative treatment, since surgeries for liver traumas carry high mortality rates. Patients admitted to the Department of Emergency Surgery at Kartal Research and Education Hospital, due to liver trauma were retrospectively analyzed between 2003 and 2013. Patient demographics, hepatic panel, APTT (activated partial thromboplastin time), PT (prothrombin time), INR (international normalized ratio), fibrinogen, biochemistry panel were recorded. Hemodynamic instability was the most prominent factor for surgery decision, in the lead of current Advanced Trauma Life Support (ATLS) protocols. Operation records and imaging modalities revealed liver injuries according to the Organ Injury Scale of the American Association for the Surgery of Trauma. 300 patients admitted to emergency department were included in our study (187 males and 113 females). Mean age was 47 years (range, 12-87). The overall mortality rate was 13% (40 out of 300). Major factor responsible for mortality rates and outcome was stability of cases on admission. 188 (% 63) patients were counted as stable, whereas 112 (% 37) cases were found unstable (blood pressure ≤ 90, after massive resuscitation). 192 patients were observed conservatively, whereas 108 cases received abdominal surgery. High levels of AST, ALT, LDH, INR, creatinine and low levels of fibrinogen and low platelet counts on admission were found to be associated with mortality and these cases also had Grade 4 and 5 injuries. Hemodynamic instability on admission and the type and grade of injury played major role in mortality rates). Packing was performed in 35 patients, with Grade 4 and 5 injuries. Mortality rate was %13 (40

  14. Current trends in ion implantation

    International Nuclear Information System (INIS)

    Gwilliam, R.M.

    2001-01-01

    As semiconductor device dimensions continue to shrink, the drive beyond 250 nm is creating significant problems for the device processor. In particular, trends toward shallower-junctions, lower thermal budgets and simplified processing steps present severe challenges to ion implantation. In parallel with greater control of the implant process goes the need for a better understanding of the physical processes involved during implantation and subsequent activation annealing. For instance, the need for an understanding of dopant-defect interaction is paramount as defects mediate a number of technologically important phenomena such as transient enhanced diffusion and impurity gettering. This paper will outline the current trends in the ion implantation and some of the challenges it faces in the next decade, as described in the semiconductor roadmap. It will highlight some recent positron annihilation work that has made a contribution to addressing one of these challenges, namely the need for tighter control of implant uniformity and dose. Additionally, some vacancy-mediated processes are described with the implication that these may provide areas in which positron annihilation spectroscopy could make a significant contribution. (orig.)

  15. Current work in energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report describes the work performed at Berkeley Lab most recently. One of the Labs accomplishments is the publication of Scenarios of US Carbon Reductions, an analysis of the potential of energy technologies to reduce carbon emissions in the US. This analysis is described and played a key role in shaping the US position on climate change in the Kyoto Protocol negotiations. The Labs participation in the fundamental characterization of the climate change issue by the IPCC is described. Described also is a study of leaking electricity, which is stimulating an international campaign for a one-watt ceiling for standby electricity losses from appliances. This ceiling has the potential to save two-thirds of the 5% of US residential electricity currently expended on standby losses. The 54 vignettes contained in the report summarize results of research activities ranging in scale from calculating the efficacy of individual lamp ballasts to estimating the cost-effectiveness of the national Energy Star{reg_sign} labeling program, and ranging in location from a scoping study of energy-efficiency market transformation in California to development of an energy-efficiency project in the auto parts industry in Shandong Province, China.

  16. Current treatment options for meningioma.

    Science.gov (United States)

    Apra, Caroline; Peyre, Matthieu; Kalamarides, Michel

    2018-03-01

    With an annual incidence of 5/100,000, meningioma is the most frequent primary tumor of the central nervous system. Risk factors are radiotherapy and hormone intake. Most meningiomas are grade I benign tumors, but up to 15% are atypical and 2% anaplastic according to the WHO 2016 histological criteria. Areas covered: This review details the current standard therapy based on international guidelines and recent literature, and describes new approaches developed to treat refractory cases. First-line treatments are observation and surgery, but adjuvant radiotherapy/radiosurgery is discussed for atypical and indicated for anaplastic meningiomas. The most problematic cases include skull base meningiomas that enclose vasculo-nervous structures and surgery- and radiation-refractory tumors that present with significant morbidity and mortality. The treatment of recurrent tumors is based on radiotherapy and repeated surgery. Systematic therapies are not effective in general but several clinical trials are ongoing. Expert commentary: Molecular characterization of the tumors, based on genetic mutations such as NF2, SMO, TERT, TRAF7, and on the methylation profile are developing, completing the histological classification and giving new insights into prognosis and treatment options.

  17. Chronic Lymphocytic Leukemia: Current Concepts.

    Science.gov (United States)

    Yu, Eun-Mi; Kittai, Adam; Tabbara, Imad A

    2015-10-01

    Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults, and while in early, asymptomatic stages treatment is not indicated, the threat to the quality of life and increased mortality of patients posed by more advanced-stage disease necessitate therapeutic intervention. Guidelines of when and how to treat are not well-established because CLL is a disease of the elderly and it is important to balance preservation of functional status and control of the disease. Advances in molecular and genetic profiling has led to the ability to identify sub-groups of patients with CLL whose disease may respond to selected therapy. This review discusses current standard therapies in the major sub-groups of CLL based on age and functional status, in both the front-line and relapsed/refractory settings. It also provides a concise review of novel agents that have shown considerable efficacy in CLL. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  18. Eddy-current probe design

    International Nuclear Information System (INIS)

    Kincaid, T.G.; McCary, R.O.

    1983-01-01

    This paper describes theoretical and experimental work directed toward finding the optimum probe dimensions and operating frequency for eddy current detection of half-penny surface cracks in nonmagnetic conducting materials. The study applies to probes which excite an approximately uniform spatial field over the length of the crack at the surface of the material. In practical terms, this means that the probe is not smaller than the crack length in any of its critical dimensions. The optimization of a simple coil probe is first analyzed in detail. It is shown that signal-to-noise ratio and lift-off discrimination are maximized by a pancake coil with mean radius not greater than the crack length, operated at a frequency which gives a skin depth equal to the crack depth. The results obtained for the simple coil are then used as a basis for discussion of the design of coils with ferrite cores and shields, and for the design of recording head type probes

  19. Uterine sarcoma – current perspectives

    Science.gov (United States)

    Benson, Charlotte; Miah, Aisha B

    2017-01-01

    Uterine sarcomas comprise a group of rare tumors with differing tumor biology, natural history and response to treatment. Diagnosis is often made following surgery for presumed benign disease. Currently, preoperative imaging does not reliably distinguish between benign leiomyomas and other malignant pathology. Uterine leiomyosarcoma is the most common sarcoma, but other subtypes include endometrial stromal sarcoma (low grade and high grade), undifferentiated uterine sarcoma and adenosarcoma. Clinical trials have shown no definite survival benefit of adjuvant radiotherapy or chemotherapy and have been hampered by the rarity and heterogeneity of these disease types. There is a role of adjuvant treatment in carefully selected cases following multidisciplinary discussion at sarcoma reference centers. In patients with metastatic disease, systemic chemotherapy can then be considered. There is activity of a number of agents, including doxorubicin, trabectedin, gemcitabine-based chemotherapy, eribulin and pazopanib. Patients should be considered for clinical trial entry where possible. Close international collaboration is important to allow progress in this group of diseases. PMID:28919822

  20. Uterine sarcoma – current perspectives

    Directory of Open Access Journals (Sweden)

    Benson C

    2017-08-01

    Full Text Available Charlotte Benson,1 Aisha B Miah1,2 1Sarcoma Unit, Royal Marsden Hospital, 2Department of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK Abstract: Uterine sarcomas comprise a group of rare tumors with differing tumor biology, natural history and response to treatment. Diagnosis is often made following surgery for presumed benign disease. Currently, preoperative imaging does not reliably distinguish between benign leiomyomas and other malignant pathology. Uterine leiomyosarcoma is the most common sarcoma, but other subtypes include endometrial stromal sarcoma (low grade and high grade, undifferentiated uterine sarcoma and adenosarcoma. Clinical trials have shown no definite survival benefit of adjuvant radiotherapy or chemotherapy and have been hampered by the rarity and heterogeneity of these disease types. There is a role of adjuvant treatment in carefully selected cases following multidisciplinary discussion at sarcoma reference centers. In patients with metastatic disease, systemic chemotherapy can then be considered. There is activity of a number of agents, including doxorubicin, trabectedin, gemcitabine-based chemotherapy, eribulin and pazopanib. Patients should be considered for clinical trial entry where possible. Close international collaboration is important to allow progress in this group of diseases. Keywords: sarcoma, leiomyosarcoma, endometrial stromal sarcoma, undifferentiated uterine sarcoma, leiomyoma

  1. Burning mouth syndrome: Current concepts

    Directory of Open Access Journals (Sweden)

    Cibele Nasri-Heir

    2015-01-01

    Full Text Available Burning mouth syndrome (BMS is a chronic pain condition. It has been described by the International Headache Society as "an intra-oral burning or dysesthetic sensation, recurring daily for more than 2 h/day for more than 3 months, without clinically evident causative lesions." BMS is frequently seen in women in the peri-menopausal and menopausal age group in an average female/male ratio of 7:1. The site most commonly affected is the anterior two-thirds of the tongue. The patient may also report taste alterations and oral dryness along with the burning. The etiopathogenesis is complex and is not well-comprehended. The more accepted theories point toward a neuropathic etiology, but the gustatory system has also been implicated in this condition. BMS is frequently mismanaged, partly because it is not well-known among healthcare providers. Diagnosis of BMS is made after other local and systemic causes of burning have been ruled out as then; the oral burning is the disease itself. The management of BMS still remains a challenge. Benzodiazepines have been used in clinical practice as the first-line medication in the pharmacological management of BMS. Nonpharmacological management includes cognitive behavioral therapy and complementary and alternative medicine (CAM. The aim of this review is to familiarize healthcare providers with the diagnosis, pathogenesis, and general characteristics of primary BMS while updating them with the current treatment options to better manage this group of patients.

  2. Burning mouth syndrome: Current concepts.

    Science.gov (United States)

    Nasri-Heir, Cibele; Zagury, Julyana Gomes; Thomas, Davis; Ananthan, Sowmya

    2015-01-01

    Burning mouth syndrome (BMS) is a chronic pain condition. It has been described by the International Headache Society as "an intra-oral burning or dysesthetic sensation, recurring daily for more than 2 h/day for more than 3 months, without clinically evident causative lesions." BMS is frequently seen in women in the peri-menopausal and menopausal age group in an average female/male ratio of 7:1. The site most commonly affected is the anterior two-thirds of the tongue. The patient may also report taste alterations and oral dryness along with the burning. The etiopathogenesis is complex and is not well-comprehended. The more accepted theories point toward a neuropathic etiology, but the gustatory system has also been implicated in this condition. BMS is frequently mismanaged, partly because it is not well-known among healthcare providers. Diagnosis of BMS is made after other local and systemic causes of burning have been ruled out as then; the oral burning is the disease itself. The management of BMS still remains a challenge. Benzodiazepines have been used in clinical practice as the first-line medication in the pharmacological management of BMS. Nonpharmacological management includes cognitive behavioral therapy and complementary and alternative medicine (CAM). The aim of this review is to familiarize healthcare providers with the diagnosis, pathogenesis, and general characteristics of primary BMS while updating them with the current treatment options to better manage this group of patients.

  3. Cranial MRI: Current clinical applications

    International Nuclear Information System (INIS)

    Bradley, W.G. Jr.; Kortman, K.E.

    1987-01-01

    Human MR images were first published by the Nottingham group in 1980. Since that time, there have been steady improvements in image quality and significant reductions in imaging time. After initial studies by the Hammersmith group in London, investigators at UCSF published studies comparing CT with MR, clearly demonstrating the higher sensitivity of MR to pathologic intracranial processes. Since that time, several investigators have demonstrated the efficacy of MR in the evaluation of a wide range of intracranial pathologic processes, including neoplasms, demyelinating disease, trauma, and congenital abnormalities. In the authors' studies comparing MR with CT in 400 consecutive cases of suspected CNS pathology, MR detected abnormalities which were not seen on CT in 30 percent of these cases. MR has become established as the imaging modality of choice in the evaluation of a broad range of CNS abnormalities and is rapidly being implemented not only at university medical centers but also in community hospitals and free-standing clinics. This chapter deals with fundamental principles of MR image interpretation and provides insight into current clinical indications for MR in intracranial disorders

  4. Prostate carcinoma: current diagnostic strategy

    International Nuclear Information System (INIS)

    Schwarzschild, Monica Maria Agata Stiepcich; Ferraz, Maria Lucia Cardoso Gomes; Oliveira, Jose Marcelo Amatuzzi; Andriolo, Adagmar

    2001-01-01

    Prostate cancer is the second cause of cancer death in men in the Western world. Despite progress in the treatment of advanced disease, it is recognized that the only possibility of reduction in prostate cancer death is nearly diagnosis when the disease is localized. In the present study our aim was to review the current strategy for diagnosis of prostate carcinoma. Prostate-specific antigen (PSA) is a valuable tumor marker and has demonstrated effectiveness in detecting prostate carcinoma, monitoring therapeutic efficacy, and disclosing disease recurrence. However, alternative methods are been proposed just as the free to total PSA ratio, PSA density, PSA velocity, which could improve the diagnostic sensibility and the specificity. Image diagnostic methods include transrectal ultra sound, computerized tomography, magnetic resonance image, and bone cintigraphy. The ultra sound is the best approach to guide the prostate biopsy and, together with the magnetic resonance is still useful for loco regional graduation. Computerized tomography as magnetic resonance image can be used for identification of linfonodal involvement. Bone cintigraphy is the best method for the identification of metastatic disease. (author)

  5. Current status of nuclear power

    International Nuclear Information System (INIS)

    Behnke, W.B.

    1984-01-01

    The decision to devote the 1984 conference to nuclear power is timely and appropriate. Illinois has a long, and distinguished history in the development of civilian nuclear power. The concept was born at the University of Chicago, developed at Argonne National Laboratory and demonstrated on the Commonwealth Edison system at our pioneer Dresden Nuclear Station. Today, Illinois ranks number one in the nation in nuclear generation. With over a quarter century of commercial operating experience, nuclear power has proven its worth and become a significant and growing component of electric power supply domestically and throughout the world. Despite its initial acceptance, however, the nuclear power industry in the U.S. is now in the midst of a difficult period of readjustment stemming largely from the economic and regulatory problems of the past decade. As a result, the costs of plants under construction have increased dramatically, causing serious financial difficulties for several projects and their owners. At the same time, the U.S. is facing hard choices concerning its future energy supplies. Conferences such as this have an important role in clarifying the issues and helping to find solutions to today's pressing energy problems. This paper summarizes the status of nuclear power both here and abroad, discussing the implications of current events in the context of national energy policy and economic development here in Illinois

  6. REACH and nanomaterials: current status

    International Nuclear Information System (INIS)

    Alessandrelli, Maria; Di Prospero Fanghella, Paola; Polci, Maria Letizia; Castelli, Stefano; Pettirossi, Flavio

    2015-01-01

    New challenges for regulators are emerging about a specific assessment and appropriate management of the potential risks of nanomaterials. In the framework of European legislation on chemicals, Regulation (EC) No. 1907/2006 REACH aims to ensure the safety of human health and the environment through the collection of information on the physico-chemical characteristics of the substances and on their profile (eco) toxicological and the identification of appropriate risk management linked to 'exposure to these substances without impeding scientific progress and the competitiveness of industry. In order to cover the current shortage of information on the safety of nanomaterials and tackle the acknowledged legal vacuum, are being a rich activities, carried out both by regulators both by stake holders, and discussions on the proposals for adapting the European regulatory framework for chemicals . The European Commission is geared to strengthen the REACH Regulation by means of updates of its annexes. The importance of responding to the regulatory requirements has highlighted the need for cooperation between European organizations, scientists and industries to promote and ensure the safe use of nanomaterials. [it

  7. Radiation dominated relativistic current sheets

    International Nuclear Information System (INIS)

    Jaroschek, C.H.

    2008-01-01

    Relativistic Current Sheets (RCS) feature plasma instabilities considered as potential key to magnetic energy dissipation and non-thermal particle generation in Poynting flux dominated plasma flows. We show in a series of kinetic plasma simulations that the physical nature of non-linear RCS evolution changes in the presence of incoherent radiation losses: In the ultra-relativistic regime (i.e. magnetization parameter sigma = 104 defined as the ratio of magnetic to plasma rest frame energy density) the combination of non-linear RCS dynamics and synchrotron emission introduces a temperature anisotropy triggering the growth of the Relativistic Tearing Mode (RTM). As direct consequence the RTM prevails over the Relativistic Drift Kink (RDK) Mode as competitive RCS instability. This is in contrast to the previously studied situation of weakly relativistic RCS (sigma ∼ 1) where the RDK is dominant and most of the plasma is thermalized. The simulations witness the typical life cycle of ultra-relativistic RCS evolving from a violent radiation induced collapse towards a radiation quiescent state in rather classical Sweet-Parker topology. Such a transition towards Sweet-Parker configuration in the late non-linear evolution has immediate consequences for the efficiency of magnetic energy dissipation and non-thermal particle generation. Ceasing dissipation rates directly affect our present understanding of non-linear RCS evolution in conventional striped wind scenarios. (author)

  8. Current Direct Neutrino Mass Experiments

    Directory of Open Access Journals (Sweden)

    G. Drexlin

    2013-01-01

    Full Text Available In this contribution, we review the status and perspectives of direct neutrino mass experiments, which investigate the kinematics of β-decays of specific isotopes (3H, 187Re, 163Ho to derive model-independent information on the averaged electron (antineutrino mass. After discussing the kinematics of β-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re. We then describe the Karlsruhe Tritium Neutrino (KATRIN experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.. To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium β-decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

  9. Current advances in orthodontic pain

    Science.gov (United States)

    Long, Hu; Wang, Yan; Jian, Fan; Liao, Li-Na; Yang, Xin; Lai, Wen-Li

    2016-01-01

    Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway—periaqueductal grey and dorsal raphe—has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future. PMID:27341389

  10. Current management of overactive bladder.

    Science.gov (United States)

    Cartwright, Rufus; Renganathan, Arasee; Cardozo, Linda

    2008-10-01

    The concept of overactive bladder has helped us address the problem of urgency and urge incontinence from a symptomatic perspective. In this review, we provide a critical summary of clinically relevant recent publications, focusing in particular on advances in our understanding of assessment methods and therapeutic interventions for overactive bladder in women. According to current definitions, the prevalence of overactive bladder in western nations is now estimated as 13.0%. Although the prevalence increases with age, the symptoms of overactive bladder may follow a relapsing and remitting course. There has been a proliferation of validated symptom and quality of life measures and increasing sophistication in the analysis of bladder diaries. The role of urodynamics in the evaluation of urgency remains uncertain, with many trials showing limited benefit as a preoperative investigation. Fluid restriction and bladder retraining remain important first-line interventions. Many new anticholinergic medications have been licensed, with limited benefits compared with existing preparations. Intravesical botulinum toxin has become a popular alternative for patients who fail oral therapies. Although there have been few important therapeutic innovations, recent publications have led to greater sophistication in assessment methods and a clearer understanding of the role of existing interventions.

  11. The status of neutral currents

    International Nuclear Information System (INIS)

    Zwirner, F.

    1987-11-01

    The situation of particle physics today is quite puzzling. On the one hand, the Standard Model (SM) of strong and electroweak interactions is consistent with all confirmed experimental data but theoretically rather unsatisfactory. On the other hand, none of the many theoretical speculations which try to go beyond the SM has (yet) received the slightest experimental support. The solution to this dilemma can only come from new data: either from the detection of a new particle threshold at high energy colliders, or from the appearance of some small discrepancy in high-precision experiments. A crucial sector for testing the SM and its extensions is that of neutral currents (NC), where an impressive amount of data has been collected in recent years. While waiting for the next generation of experiments, it is certainly useful to take stock of our knowledge, determining the NC parameters as precisely as we can and putting limits on possible deviations from the SM. The present talk contains the results of a recent analysis along these lines: the first part illustrates how a set of 'model-independent' parameters can be extracted from the available NC data, the second part particularizes the analysis to the SM and to some superstring-inspired models with an additional Z' in their low-energy spectrum. 27 refs., 3 figs., 1 tab

  12. Static properties of the nucleon octet in a relativistic potential model with center-of-mass correction

    International Nuclear Information System (INIS)

    Barik, N.; Dash, B.K.; Das, M.

    1985-01-01

    The static properties, such as magnetic moment, charge radius, and axial-vector coupling constants, of the quark core of baryons in the nucleon octet have been studied in an independent-quark model based on the Dirac equation with equally mixed scalar-vector potential in harmonic form in the current quark mass limit. The results obtained with the corrections due to center-of-mass motion are in reasonable agreement with experimental values

  13. Chiral filter, axial charges and Gamow-Teller strengths

    International Nuclear Information System (INIS)

    Rho, M.

    1983-09-01

    The different ways that nuclear matter responds to the weak axial-vector current are interpreted in terms of modification of the ''vacuum'' in baryon-rich environments. The notion of ''chiral filter'' is introduced. Use of a ward identity is suggested. The Gamow-Teller quenching and the enhanced axial charge in O + O - transitions follow from this. I also discuss briefly possible relevance of the nucleon as a topological soliton configuration to the global property of nuclear axial response functions

  14. Surface terms and radiative corrections to the VVA triangle diagram

    International Nuclear Information System (INIS)

    Chowdhury, A.M.; McKeon, G.

    1986-01-01

    The two-loop radiative corrections to the divergence of the axial-vector current are analyzed in the context of spinor electrodynamics. It is found that the arbitrariness that occurs in the relevant Feynman diagrams due to the appearance of surface terms associated with linearly divergent integrals is sufficient to ensure that at two-loop order the Ward identity can be satisfied, irrespective of how the divergences that occur are parametrized. This indicates that the Adler-Bardeen theorem is satisfied

  15. β-decay in the Skyrme-Witten representation of QCD

    International Nuclear Information System (INIS)

    Snyderman, N.J.

    1991-01-01

    The renormalized coupling strength of the β-decay axial vector current is related to π ± p cross sections through the Adler-Weisberger sum rule, that follows from chiral symmetry. We attempt to understand the Adler-Weisberger sum rule in the 1/N c expansion in QCD, and in Skyrme-Witten model that realizes the 1/N c expansion in the low energy limit, using it to explicitly calculate both g A and the π ± p cross sections

  16. gsub(ωrhoπ) coupling constant from QCD sum rules

    International Nuclear Information System (INIS)

    Eletsky, V.L.; Ioffe, B.L.; Kogan, Ya.I.

    1982-01-01

    QCD sum rules for the vertex function of two vector and one axial vector currents are used to calculate the gsub(ωrhoπ) coupling constant (where gsub(ωrhoπ) is a transition coupling constant for ω → rhoπ process). The obtained value, gsub(ωrhoπ) approximately 17 GeV -1 is in a good agreement with experimental data

  17. Calculation of electromagnetic rhoπ formfactor from QCD sum rules

    International Nuclear Information System (INIS)

    Eletskij, V.L.; Kogan, Ya.I.

    1982-01-01

    Electromagnetic rhoπγ form factor at intermediate momentum transfer, 0.7 GeV 2 2 2 , is calculated using QCD sum rules for the vertex function of two vector and one axial-vector currents. In this region the results obtained are consistent within 25% accuracy with the vector meson dominance model predictions and can be regarded as its theoretical ustification

  18. Current trends in geomorphological mapping

    Science.gov (United States)

    Seijmonsbergen, A. C.

    2012-04-01

    Geomorphological mapping is a world currently in motion, driven by technological advances and the availability of new high resolution data. As a consequence, classic (paper) geomorphological maps which were the standard for more than 50 years are rapidly being replaced by digital geomorphological information layers. This is witnessed by the following developments: 1. the conversion of classic paper maps into digital information layers, mainly performed in a digital mapping environment such as a Geographical Information System, 2. updating the location precision and the content of the converted maps, by adding more geomorphological details, taken from high resolution elevation data and/or high resolution image data, 3. (semi) automated extraction and classification of geomorphological features from digital elevation models, broadly separated into unsupervised and supervised classification techniques and 4. New digital visualization / cartographic techniques and reading interfaces. Newly digital geomorphological information layers can be based on manual digitization of polygons using DEMs and/or aerial photographs, or prepared through (semi) automated extraction and delineation of geomorphological features. DEMs are often used as basis to derive Land Surface Parameter information which is used as input for (un) supervised classification techniques. Especially when using high-res data, object-based classification is used as an alternative to traditional pixel-based classifications, to cluster grid cells into homogeneous objects, which can be classified as geomorphological features. Classic map content can also be used as training material for the supervised classification of geomorphological features. In the classification process, rule-based protocols, including expert-knowledge input, are used to map specific geomorphological features or entire landscapes. Current (semi) automated classification techniques are increasingly able to extract morphometric, hydrological

  19. Current directions in radiopharmaceutical research

    Energy Technology Data Exchange (ETDEWEB)

    Mather, S J [Department of Nuclear Medicine, St. Bartholomew` s Hospital, London (United Kingdom)

    1998-08-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author) 36 refs

  20. Current insights in allergen immunotherapy.

    Science.gov (United States)

    Passalacqua, Giovanni; Bagnasco, Diego; Ferrando, Matteo; Heffler, Enrico; Puggioni, Francesca; Canonica, Giorgio Walter

    2018-02-01

    Allergen-specific immunotherapy (AIT) in its subcutaneous and sublingual forms is currently a well-established and experimentally supported treatment for respiratory allergy and hymenoptera venom allergy. There have been advances in its use linked strictly to the advancement in the knowledge of the molecular mechanisms of allergy, the production of well-characterized extracts, and diagnostic techniques. The use of AIT in asthma and the application of new approaches are expanding. We briefly review the advances and concerns in the use of AIT. PubMed and Scopus. The most recent and clinically relevant literature was selected and reviewed. The introduction of high-quality products supported by large dose-finding trials has yielded better defined indications, contraindications, and modalities of use. Some specific products in tablet form have recently been approved in the United States. Sublingual immunotherapy has been found to be effective in asthma, which until recently had been a matter of debate. Another promising therapy is oral and sublingual desensitization for food allergy, for which encouraging results have recently been reported. In the near future, other options will be available, including new routes of administration (intralymphatic and epicutaneous), allergoids, engineered allergens, and peptides. The use of component-resolved diagnosis techniques will further refine and target AIT prescriptions. This condensed and updated review shows that AIT remains a viable treatment option, especially after the introduction of standardized tablets for some allergens. Food allergy and new administration routes represent a promising expansion. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  1. Current status of rotational atherectomy.

    Science.gov (United States)

    Tomey, Matthew I; Kini, Annapoorna S; Sharma, Samin K

    2014-04-01

    Rotational atherectomy facilitates percutaneous coronary intervention for complex de novo lesions with severe calcification. A strategy of routine rotational atherectomy has not, however, conferred reduction in restenosis or major adverse cardiac events. As it is technically demanding, rotational atherectomy is also uncommon. At this 25-year anniversary since the introduction of rotational atherectomy, we sought to review the current state-of-the-art in rotational atherectomy technique, safety, and efficacy data in the modern era of drug-eluting stents, strategies to prevent and manage complications, including slow-flow/no-reflow and burr entrapment, and appropriate use in the context of the broader evolution in the management of stable ischemic heart disease. Fundamental elements of optimal technique include use of a single burr with burr-to-artery ratio of 0.5 to 0.6-rotational speed of 140,000 to 150,000 rpm, gradual burr advancement using a pecking motion, short ablation runs of 15 to 20 s, and avoidance of decelerations >5,000 rpm. Combined with meticulous technique, optimal antiplatelet therapy, vasodilators, flush solution, and provisional use of atropine, temporary pacing, vasopressors, and mechanical support may prevent slow-flow/no-reflow, which in contemporary series is reported in 0.0% to 2.6% of cases. On the basis of the results of recent large clinical trials, a subset of patients with complex coronary artery disease previously assigned to rotational atherectomy may be directed instead to medical therapy alone or bypass surgery. For patients with de novo severely calcified lesions for which rotational atherectomy remains appropriate, referral centers of excellence are required. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  2. Current therapy for Parkinson's disease

    Directory of Open Access Journals (Sweden)

    A. V. Obukhova

    2014-01-01

    Full Text Available The main goal of therapy for Parkinson's disease (PD is to correct dopamine deficiency in the nigrostriatal system. Levodopa preparations and dopamine receptor agonists (DRAs that are prescribed with regards to patient age and disease severity are mainly used now. Notwithstanding the fact that levodopa preparations are the gold standard of therapy, their long-term use gives rise to complications as motor fluctuations and drug-induced dyskinesias. The currently available DRAs are the drugs of choice for the therapy of early-stage PD as they are as effective as levodopa preparations. In extensive-stage PD, DRAs are used to enhance the therapy and correction of developed motor fluctuations and dyskinesias. Pramipexole is one of the most commonly used representatives of non-ergoline DRAs. The paper analyzes the efficacy of the medication used as both monotherapy and part of combined therapy, its effect on tremor and depression in PD. A novel extended-release formulation of pramipexole is considered separately. Both immediate- and extended-release pramipexole formulations contain the same active ingredient and have the same dopamine-receptor interaction profile, but differ in the tablet release rate of the active ingredient. The advantages of the novel formulation are its more steady-state plasma concentration and 24-hour action, which ensures continuous dopaminergic stimulation ofpostsynaptic receptors to prevent and treat already developed motor complications. The once-daily extended-release formulation of the drug makes its treatment regimen easier and patient compliance higher.

  3. Current status of diuretic renography

    International Nuclear Information System (INIS)

    O'Reilly, P.H.

    1987-01-01

    Percutaneous antegrade perfusion studies constitute a valuable contribution to the investigation of obstructive uropathy. In 1978, the first report of application of diuretic renogram techniques to this problem appeared in the literature. This was the first systematic report of a standardized protocol to be applied to a specific surgical problem. The purpose of the procedure, as with perfusion pressure-flow studies, is to help distinguish between a dilated urinary tract that is obstructed and requires surgery and a nonobstructed system in which urographic dilation and stasis mimic obstruction, but no genuine impedance to urine flow exists, and surgery is not required. The technique provides dual information. It gives quantitative data on individual renal function that perfusion pressure-flow studies do not, and it gives time-activity curves reflecting the urodynamics through the individual upper urinary tracts at normal and high urinary flow rates. In the early days, this information was obtained from probe studies, but the procedure is now almost exclusively performed using the gamma camera, images from which give additional information on the site of any suspected obstruction. In some ways, the development of diuretic renography and that of perfusion pressure-flow studies have proceeded in a competitive fashion, both attempting to answer the same questions by different means. In practice, however, the two tests would be regarded as complementary, as will be shown later in this chapter. The following sections describe the technique of diuretic renography, its current clinical application and status in surgical and nuclear medicine practice, and its role in comparison with other available tests for management of the dilated upper urinary tract

  4. Recurrent pregnancy loss: current perspectives

    Directory of Open Access Journals (Sweden)

    El Hachem H

    2017-05-01

    Full Text Available Hady El Hachem,1,2 Vincent Crepaux,3 Pascale May-Panloup,4 Philippe Descamps,3 Guillaume Legendre,3 Pierre-Emmanuel Bouet3 1Department of Reproductive Medicine, Ovo Clinic, Montréal, QC, Canada; 2Department of Obstetrics and Gynecology, University of Montreal, Montréal, QC, Canada; 3Department of Obstetrics and Gynecology, Angers University Hopsital, Angers, France; 4Department of Reproductive Biology, Angers University Hospital, Angers, France Abstract: Recurrent pregnancy loss is an important reproductive health issue, affecting 2%–5% of couples. Common established causes include uterine anomalies, antiphospholipid syndrome, hormonal and metabolic disorders, and cytogenetic abnormalities. Other etiologies have been proposed but are still considered controversial, such as chronic endometritis, inherited thrombophilias, luteal phase deficiency, and high sperm DNA fragmentation levels. Over the years, evidence-based treatments such as surgical correction of uterine anomalies or aspirin and heparin for antiphospholipid syndrome have improved the outcomes for couples with recurrent pregnancy loss. However, almost half of the cases remain unexplained and are empirically treated using progesterone supplementation, anticoagulation, and/or immunomodulatory treatments. Regardless of the cause, the long-term prognosis of couples with recurrent pregnancy loss is good, and most eventually achieve a healthy live birth. However, multiple pregnancy losses can have a significant psychological toll on affected couples, and many efforts are being made to improve treatments and decrease the time needed to achieve a successful pregnancy. This article reviews the established and controversial etiologies, and the recommended therapeutic strategies, with a special focus on unexplained recurrent pregnancy losses and the empiric treatments used nowadays. It also discusses the current role of preimplantation genetic testing in the management of recurrent pregnancy

  5. Current directions in radiopharmaceutical research

    International Nuclear Information System (INIS)

    Mather, S.J.

    1998-01-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author)

  6. Current Knowledge on Hepatitis E.

    Science.gov (United States)

    Pérez-Gracia, María Teresa; García, Mario; Suay, Beatriz; Mateos-Lindemann, María Luisa

    2015-06-28

    Although only a single serotype of hepatitis E virus (HEV), the causative agent of hepatitis E, has been identified, there is great genetic variation among the different HEV isolates reported. There are at least four major recognized genotypes of HEV: genotypes 1 and 2 are mainly restricted to humans and linked to epidemic outbreaks in nonindustrialized countries, whereas genotypes 3 and 4 are zoonotic in both developing and industrialized countries. Besides human strains, genotype 3 and 4 strains of HEV have been genetically characterized from swine, sika deer, mongooses, sheep, and rabbits. Currently, there are approximately 11,000 human and animal sequences of HEV available at the International Nucleotide Sequence Database Collaboration. HEV is the major cause of waterborne outbreaks of hepatitis in areas of poor sanitation. Additionally, it is responsible for sporadic cases of viral hepatitis in not only endemic but industrialized countries as well. Transmission of HEV occurs predominantly by the fecal-oral route, although parenteral and perinatal routes have been reported. HEV infection develops in most individuals as a self-limiting, acute, icteric hepatitis; with mortality rates around 1%. However, some affected individuals will develop fulminant hepatic failure, a serious condition that is frequently fatal without a liver transplant. This complication is particularly common when the infection occurs in pregnant women, where mortality rates rise dramatically to up to 25%. Among the preventive measures available to avoid HEV infection, two separate subunit vaccines containing recombinant truncated capsid proteins of HEV have been shown to be highly effective in the prevention of disease. One of them, HEV 239, was approved in China, and its commercialization by Innovax began in November 2012 under the name Hecolin(®).

  7. Current nutritional treatments of obesity.

    Science.gov (United States)

    Greenwald, Ashli

    2006-01-01

    Obesity in our country is a growing concern. There are several different options for weight loss; however, individuals must be self-motivated and amendable to change in order to achieve success with their weight loss goals. Several strategies used by professionals in the US today to treat overweight and obesity, include diet therapy, exercise, behavior modification, pharmacotherapy, and surgery. The focus of the American Dietetic Association (ADA) Weight Management Position Statement is no longer just on weight loss but now on weight management. Reaching one's ideal body weight is recommended but not often realistic. Frequently, the goal of treatment shifts to maintenance of ones current weight or attempts at moderate weight loss. Lifestyle modification or behavioral modification interventions rely on analyzing behavior to identify events that are associated with appropriate vs. inappropriate eating, exercise, or thinking habits. Certain primary strategies that have been found to be useful for helping people change their behaviors so that they can lose weight and maintain their weight loss, include self-monitoring, stimulus control, cognitive restructuring, stress management, social support, physical activity, and relapse prevention. Weight loss programs should strive to combine a nutritionally balanced dietary regimen with exercise and lifestyle modifications at the lowest possible cost. There are several different methods used for dietary modifications; low calorie diets, very low calorie diets, fasting, formula diets and meal replacement programs, and popular diets. Bariatric surgery is gaining popularity as it has been an effective way to treat obesity. Following gastric bypass surgery, the patients must be prepared to modify their eating behaviors and dietary selections to assist with weight loss and prevent potential complications. Patients should be educated on the dietary guidelines extensively prior to surgery and again post-operatively.

  8. Oppositional defiant disorder: current insight

    Directory of Open Access Journals (Sweden)

    Ghosh A

    2017-11-01

    Full Text Available Abhishek Ghosh,1 Anirban Ray,2 Aniruddha Basu1 1Drug De-addiction and Treatment Centre, Department of Psychiatry, Postgraduate Institute of Medical Education and Research (PGIMER, Chandigarh, 2Department of Psychiatry, Institute of Psychiatry, Institute of Post Graduate Medical Education and Research, Kolkata, India Abstract: Oppositional defiant disorder (ODD is diagnosed broadly on the basis of frequent and persistent angry or irritable mood, argumentativeness/defiance, and vindictiveness. Since its inception in the third Diagnostic and Statistical Manual of Mental Disorders, epidemiological and longitudinal studies have strongly suggested a distinct existence of ODD that is different from other closely related externalizing disorders, with different course and outcome and possibly discrete subtypes. However, several issues, such as symptom threshold, dimensional versus categorical conceptualization, and sex-specific symptoms, are yet to be addressed. Although ODD was found to be highly heritable, no genetic polymorphism has been identified with confidence. There has been a definite genetic overlap with other externalizing disorders. Studies have begun to explore its epigenetics and gene–environment interaction. Neuroimaging findings converge to implicate various parts of the prefrontal cortex, amygdala, and insula. Alteration in cortisol levels has also been demonstrated consistently. Although a range of environmental factors, both familial and extrafamilial, have been studied in the past, current research has combined these with other biological parameters. Psychosocial treatment continues to be time-tested and effective. These include parental management training, school-based training, functional family therapy/brief strategic family therapy, and cognitive behavior therapy. Management of severe aggression and treatment of co-morbid disorders are indications for pharmacotherapy. In line with previous conceptualization of chronic

  9. Frontotemporal lobar degeneration: current perspectives

    Directory of Open Access Journals (Sweden)

    Riedl L

    2014-02-01

    inhibitors to reduce behavioral disturbances. No large-scale or high-quality studies have been conducted to determine the efficacy of non-pharmacological treatment approaches in FTLD. In view of the limited treatment options, caregiver education and support is currently the most important component of the clinical management. Keywords: review, frontotemporal dementia, frontotemporal lobar degeneration

  10. Anorexia of infection: current prospects.

    Science.gov (United States)

    Langhans, W

    2000-10-01

    infection appear to be neurochemicals involved in the normal control of feeding, such as serotonin, dopamine, histamine, corticotropin releasing factor, neuropeptide Y, and alpha-melanocyte-stimulating hormone. Reciprocal, synergistic, and antagonistic interactions between various pleiotropic cytokines, and between cytokines and neurochemicals, form a complex network that mediates the anorexia during infection. Current knowledge on the mechanisms involved suggests some therapeutic options for treatment. Substances that block common key steps in cytokine synthesis or cytokine action, or inhibitors of eicosanoid synthesis, may hold more promise than attempts to antagonize specific cytokines. To target the neurochemical mediation of the anorexia during infection may be even more efficient. Future research should address these neurochemical mechanisms and the cytokine actions at the blood-brain barrier. Further unanswered questions concern the modulation of the anorexia during infection by gender and nutritional state.

  11. rasdaman Array Database: current status

    Science.gov (United States)

    Merticariu, George; Toader, Alexandru

    2015-04-01

    rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which

  12. Toroidal current asymmetry in tokamak disruptions

    Science.gov (United States)

    Strauss, H. R.

    2014-10-01

    It was discovered on JET that disruptions were accompanied by toroidal asymmetry of the toroidal plasma current I ϕ. It was found that the toroidal current asymmetry was proportional to the vertical current moment asymmetry with positive sign for an upward vertical displacement event (VDE) and negative sign for a downward VDE. It was observed that greater displacement leads to greater measured I ϕ asymmetry. Here, it is shown that this is essentially a kinematic effect produced by a VDE interacting with three dimensional MHD perturbations. The relation of toroidal current asymmetry and vertical current moment is calculated analytically and is verified by numerical simulations. It is shown analytically that the toroidal variation of the toroidal plasma current is accompanied by an equal and opposite variation of the toroidal current flowing in a thin wall surrounding the plasma. These currents are connected by 3D halo current, which is π/2 radians out of phase with the n = 1 toroidal current variations.

  13. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  14. Neutral currents without gauge theory prejudices

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1976-01-01

    The measurement of weak neutral current processes allows a determination of the space-time structure and the isospin structure of these currents. The inclusive production data and the elastic neutrino electron scattering rules out a pure V or A structure of the current. A pure isoscalar current is in disagreement with the experimental data for the one pion production off neutrinos. Further aspects of the neutral current can be determined in neutrino-nucleus-scattering experiments. (BJ) [de

  15. Study of $\\tau$ decays involving kaons, spectral functions and determination of the strange quark mass

    CERN Document Server

    Barate, R.; Ghez, Philippe; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Alemany, R.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Juste, A.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Park, I.C.; Riu, I.; Colaleo, A.; Creanza, D.; De Palma, M.; Gelao, G.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Becker, U.; Boix, G.; Cattaneo, M.; Ciulli, V.; Dissertori, G.; Drevermann, H.; Forty, R.W.; Frank, M.; Halley, A.W.; Hansen, J.B.; Harvey, John; Janot, P.; Jost, B.; Lehraus, I.; Leroy, O.; Mato, P.; Minten, A.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Rousseau, D.; Schlatter, D.; Schmitt, M.; Schneider, O.; Tejessy, W.; Teubert, F.; Tomalin, I.R.; Tournefier, E.; Wright, A.E.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Rensch, B.; Waananen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Cavanaugh, R.; Corden, M.; Georgiopoulos, C.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Teixeira-Dias, P.; Thompson, A.S.; Buchmuller, O.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Goodsir, S.; Martin, E.B.; Marinelli, N.; Sedgbeer, J.K.; Spagnolo, P.; Thomson, Evelyn J.; Williams, M.D.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Betteridge, A.P.; Bowdery, C.K.; Buck, P.G.; Colrain, P.; Crawford, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Robertson, N.A.; Williams, M.I.; Giehl, I.; Hoffmann, C.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; van Gemmeren, P.; Wachsmuth, H.; Zeitnitz, C.; Aubert, J.J.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Etienne, F.; Motsch, F.; Payre, P.; Talby, M.; Thulasidas, M.; Aleppo, M.; Antonelli, M.; Ragusa, F.; Berlich, R.; Buescher, Volker; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Schael, S.; Settles, R.; Seywerd, H.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Azzurri, P.; Boucrot, J.; Callot, O.; Chen, S.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Hocker, Andreas; Jacholkowska, A.; Kim, D.W.; Le Diberder, F.; Lefrancois, J.; Lutz, A.M.; Schune, M.H.; Veillet, J.J.; Videau, I.; Zerwas, D.; Bagliesi, Giuseppe; Bettarini, S.; Boccali, T.; Bozzi, C.; Calderini, G.; Dell'Orso, R.; Ferrante, I.; Foa, L.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P.S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Tenchini, R.; Vannini, C.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Botterill, D.R.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Thompson, J.C.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Konstantinidis, N.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Kelly, M.S.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Prange, G.; Giannini, G.; Gobbo, B.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Charles, E.; Elmer, P.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Greening, T.C.; Hayes, O.J.; Hu, H.; Jin, S.; McNamara, P.A., III; Nachtman, J.M.; Nielsen, J.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

    1999-01-01

    All ALEPH measurements of branching ratios of tau decays involving kaons are summarized including a combination of results obtained with K^0_S and K^0_L detection. The decay dynamics are studied, leading to the determination of contributions from vector K^*(892) and K^{*}(1410), and axial-vector K_1(1270) and K_1(1400) resonances. Agreement with isospin symmetry is observed among the different final states. Under the hypothesis of the conserved vector current, the spectral function for the K\\bar{K}\\pi mode is compared with the corresponding cross section for low energy e^+e^- annihilation, yielding an axial-vector fraction of (94^{+6}_{-8})% for this mode. The branching ratio for tau decay into all strange final states is determined to be B(\\tau^-\\to X^-(S=-1)\

  16. Neoclassical MHD equilibria with ohmic current

    International Nuclear Information System (INIS)

    Tokuda, Shinji; Takeda, Tatsuoki; Okamoto, Masao.

    1989-01-01

    MHD equilibria of tokamak plasmas with neoclassical current effects (neoclassical conductivity and bootstrap current) were calculated self-consistently. Neoclassical effects on JFT-2M tokamak plasmas, sustained by ohmic currents, were studied. Bootstrap currents flow little for L-mode type equilibria because of low attainable values of poloidal beta, β J . H-mode type equilibria give bootstrap currents of 30% ohmic currents for β J attained by JFT-2M and 100% for β J ≥ 1.5, both of which are sufficient to change the current profiles and the resultant MHD equilibria. Neoclassical conductivity which has roughly half value of the classical Spitzer conductivity brings peaked ohmic current profiles to yield low safety factor at the magnetic axis. Neoclassical conductivity reduces the value of effective Z(Z eff ) which is necessary to give the observed one-turn voltage but it needs impurities accumulating at the center when such peaked current profiles are not observed. (author)

  17. Overview of current chelation practices

    Directory of Open Access Journals (Sweden)

    Y. Aydinok

    2011-12-01

    , should provide long-term survival and quality of life for patients with iron loading anemias. The goal of this review is to summarize current concepts in iron chelation therapies based on the considerable amount of prospective data obtained by clinical studies. 去铁胺 (DFO)是自20世纪80年以来输血引起铁过载的参考标准疗法。 虽然它是一种高效的铁螯合剂,但是去铁胺皮下给药的遵从性问题依旧是主要问题。 口服螯合剂去铁酮(DFP)在北美没有销售许可证,但是,它在1994年获得印度许可,1999年欧洲联盟(EU)批准授予去铁酮销售许可证,特别是当去铁胺不足、无法忍受或无法接受时,去铁酮可用于重型地中海贫血患者。 还可获得关于在6岁至10岁之间的儿童身上使用去铁酮的有限数据,但是没有关于在6岁以下儿童身上使用去铁酮的数据。 随后美国食品和药品管理局(FDA)和欧洲药品管理局(EMA)分别在2005年和2006年批准口服螯合剂去铁酮作为第一疗法来治疗2岁以上输血引起铁过载的患者。 铁螯合的主要目的是将身体铁维持在安全水平,但一旦铁累积起来,铁螯合的目标是把组织铁降低到安全级别,这是一个缓慢的过程。 确定螯合剂的螯合方案、剂量和频率管理的主要依据是身体铁负担、心肌铁的状态和输血铁负载速率。 适当监控螯合对测量特殊方案的反应速率和提供计量调整来加强螯合效果和避免毒效尤其重要。 由于一些因素,诸如:螯合剂的吸收和代谢,螯合方案的效果可能呈现个别变化。 耐受性和遵从性也是影响螯合反应的个别变量。 了解螯合剂的优点和局限性,准确确定铁过载患者的螯合需求以及设计毒效更小但效果更优的个性化螯合方案,可以向铁过载贫血患者提供长期的生存和生活质量。 此次调研的目的是在临床研究获得的相当数

  18. Non-inductively driven currents in JET

    International Nuclear Information System (INIS)

    Challis, C.D.; Cordey, J.G.; Hamnen, H.; Stubberfield, P.M.; Christiansen, J.P.; Lazzaro, E.; Muir, D.G.; Stork, D.; Thompson, E.

    1989-01-01

    Neutral beam heating data from JET have been analysed in detail to determine what proportion of the current is driven non-inductively. It is found that in low density limiter discharges, currents of the order of 0.5 MA are driven, while in H-mode plasmas currents of the order of 0.7 MA are measured. These measured currents are found to be in reasonable agreement with theoretical predictions based on neoclassical models. In low density plasmas the beam driven current is large while the neoclassical bootstrap current dominates H-mode plasmas. (author). 19 refs, 11 figs

  19. Bifurcation of Jovian magnetotail current sheet

    Directory of Open Access Journals (Sweden)

    P. L. Israelevich

    2006-07-01

    Full Text Available Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer and double-peaked (bifurcated current sheet. Magnetic field measurements in the Jovian magnetic tail by Voyager-2 reveal bifurcation of the tail current sheet. The electric current density possesses a minimum at the point of the Bx-component reversal and two maxima at the distance where the magnetic field strength reaches 50% of its value in the tail lobe.

  20. Bifurcation of Jovian magnetotail current sheet

    Directory of Open Access Journals (Sweden)

    P. L. Israelevich

    2006-07-01

    Full Text Available Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer and double-peaked (bifurcated current sheet. Magnetic field measurements in the Jovian magnetic tail by Voyager-2 reveal bifurcation of the tail current sheet. The electric current density possesses a minimum at the point of the Bx-component reversal and two maxima at the distance where the magnetic field strength reaches 50% of its value in the tail lobe.

  1. High altitude observations of Birkeland currents

    International Nuclear Information System (INIS)

    Russell, C.T.

    1977-01-01

    Birkeland or field-aligned currents are thought to play a fundamental role in many magnetospheric processes. These roles are reviewed together with observations of Birkeland currents in the distant magnetosphere

  2. Development of Multichannel Eddy Current Testing Instrument

    International Nuclear Information System (INIS)

    Lee, Hee Jong; Cho, Chan Hee; Nam, Min Woo; Yoon, Byung Sik; Yoo, Hyun Joo

    2010-01-01

    Four main techniques of electromagnetic testing are used for commercial applications: eddy current testing, alternating current field testing, magnetic flux leakage testing and remote field testing. Eddy current testing is a nondestructive evaluation method, which makes eddy current flow on a specimen by applying driving pulse to eddy current probe coil, by using eddy current testing device, and makes the change of eddy current which is dependently caused by flaws, material characteristics, testing condition, receiving through eddy current, and analyzes material properties, flaws, status on the specimen. Application of EC instrumentation varies widely in industry from the identification of metal heat treatment to the inspection of steam generator tubing in nuclear power plants. In this study, we have designed multichannel EC instrument which can be applicable to the NDE of the tube in heat exchanger for electric power facility, chemistry, and military industry, and finally confirmed the proper function of EC instrumentation

  3. Definition of total bootstrap current in tokamaks

    International Nuclear Information System (INIS)

    Ross, D.W.

    1995-01-01

    Alternative definitions of the total bootstrap current are compared. An analogous comparison is given for the ohmic and auxiliary currents. It is argued that different definitions than those usually employed lead to simpler analyses of tokamak operating scenarios

  4. Current Cigarette Smoking Among Adults Infographic

    Data.gov (United States)

    U.S. Department of Health & Human Services — Explore the Current Cigarette Smoking Among Adults Infographic which outlines key facts related to current smoking among adults. For accessibility issues contact...

  5. Power spectra of currents off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Current measurements were carried out using a recording current meter across the continental shelf off Bombay, Maharashtra, India at 4 stations from an anchored ship. Power spectra were computed for selected lengths of records. Spectral energy...

  6. Terrorism: Current and Long Term Threats

    National Research Council Canada - National Science Library

    Jenkins, Brian

    2001-01-01

    Despite the high level of anxiety the American people are currently experiencing, we may still not fully comprehend the seriousness of the current and near-term threats we confront or the longer-term...

  7. Lower hybrid current drive in shaped tokamaks

    International Nuclear Information System (INIS)

    Kesner, J.

    1993-01-01

    A time dependent lower hybrid current drive tokamak simulation code has been developed. This code combines the BALDUR tokamak simulation code and the Bonoli/Englade lower hybrid current drive code and permits the study of the interaction of lower hybrid current drive with neutral beam heating in shaped cross-section plasmas. The code is time dependent and includes the beam driven and bootstrap currents in addition to the current driven by the lower hybrid system. Examples of simulations are shown for the PBX-M experiment which include the effect of cross section shaping on current drive, ballooning mode stabilization by current profile control and sawtooth stabilization. A critical question in current drive calculations is the radial transport of the energetic electrons. The authors have developed a response function technique to calculate radial transport in the presence of an electric field. The consequences of the combined influences of radial diffusion and electric field acceleration are discussed

  8. Current algebra, baryons and quark confinement

    International Nuclear Information System (INIS)

    Witten, E.

    1983-01-01

    It is shown that ordinary baryons can be understood as solitons in current algebra effective lagrangiangs. The formation of color flux tubes can also be seen in current algebra, under certain conditions. (orig.)

  9. Characterization of plasma current quench at JET

    International Nuclear Information System (INIS)

    Riccardo, V; Barabaschi, P; Sugihara, M

    2005-01-01

    Eddy currents generated during the fastest disruption current decays represent the most severe design condition for medium and small size in-vessel components of most tokamaks. Best-fit linear and instantaneous plasma current quench rates have been extracted for a set of recent JET disruptions. Contrary to expectations, the current quench rate spectrum of high and low thermal energy disruptions is not substantially different. For most of the disruptions with the highest instantaneous current quench rate an exponential fit of the early phase of the current decay provides a more accurate estimate of the maximum current decay velocity. However, this fit is only suitable to model the fastest events, for which the current quench is dominated by radiation losses rather than the plasma motion

  10. Observed eddy dissipation in the Agulhas Current

    CSIR Research Space (South Africa)

    Braby, L

    2016-08-01

    Full Text Available (negative) velocity anomalies propagate downstream in the Agulhas Current at 44 km/d (23 km/d). Many models are unable to represent these eddy dissipation processes, affecting our understanding of the Agulhas Current....

  11. Linearized dynamical approach to current algebra

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1995-07-01

    We study the original motivations searching for a nonlinear chiral Lagrangian to replace the linear sigma model while manifesting all the successful properties of current algebra and partial conservation of axial currents (PCAC). (author). 26 refs

  12. Improving Current Balance In Parallel MOSFET's

    Science.gov (United States)

    Niedra, Janis M.

    1992-01-01

    Simple circuit makes currents more nearly equal. Addition of diodes and adjustable-tap resistor increases operating range over which drain currents in two unmatched power MOSFET's brought more nearly into balance.

  13. The Current State of Music Therapy Theory?

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2015-01-01

    An essay on themes from Ken Aigen (2014): "The Study of Music Therapy. Current Issues and Concepts"......An essay on themes from Ken Aigen (2014): "The Study of Music Therapy. Current Issues and Concepts"...

  14. Wave attenuation in the Agulhas current

    CSIR Research Space (South Africa)

    Grundlingh, M

    1995-07-01

    Full Text Available The enlargement of surface wave height in the Agulhas Current, caused by waves propagating in the opposite direction to the current, is well known for its danger to large vessels traversing the Cape route. Occurrence characteristics...

  15. Conservation of Charge and Conservation of Current

    OpenAIRE

    Eisenberg, Bob

    2016-01-01

    Conservation of current and conservation of charge are nearly the same thing: when enough is known about charge movement, conservation of current can be derived from conservation of charge, in ideal dielectrics, for example. Conservation of current is enforced implicitly in ideal dielectrics by theories that conserve charge. But charge movement in real materials like semiconductors or ionic solutions is never ideal. We present an apparently universal derivation of conservation of current and ...

  16. The Current Status of STEM Education Research

    Science.gov (United States)

    Brown, Josh

    2012-01-01

    This paper explores the current Science, Technology, Engineering and Mathematics (STEM) education research base through an analysis of articles from eight journals focused on the STEM disciplines. Analyzed are both practitioner and research publications to determine the current scope of STEM education research, where current STEM education…

  17. Current density profile evolution in JET

    International Nuclear Information System (INIS)

    Stubberfield, P.M.; Balet, B.; Campbell, D.; Challis, C.D.; Cordey, J.G.; O'Rourke, J.; Hammett, G.; Schmidt, G.L.

    1989-01-01

    Simulation studies have been made of the current density profile evolution in discharges where the bootstrap current is expected to be significant. The changes predicted in the total current profile have been confirmed by comparison with experimental results. (author) 8 refs., 6 figs

  18. Noise Properties of CMOS Current Conveyors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1996-01-01

    The definition of the current conveyor is presented and it is shown how different generations of current conveyors can all be combined into a single definition of a multiple-output second generation current conveyor (CCII). Next, noise sources are introduced into the model, and a general noise...

  19. Aquantis Ocean Current Turbine Development Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Alex J.

    2014-08-23

    The Aquantis® Current Plane (“C-Plane”) technology developed by Dehlsen Associates, LLC (DA) and Aquantis, Inc. is an ocean current turbine designed to extract kinetic energy from ocean currents. The technology is capable of achieving competitively priced base-load, continuous, and reliable power generation from a source of renewable energy not before possible in this scale or form.

  20. Neutron induced current pulses in fission chambers

    International Nuclear Information System (INIS)

    Taboas, A.L.; Buck, W.L.

    1978-01-01

    The mechanism of neutron induced current pulse generation in fission chambers is discussed. By application of the calculated detector transfer function to proposed detector current pulse shapes, and by comparison with actually observed detector output voltage pulses, a credible, semi-empirical, trapezoidal pulse shape of chamber current is obtained

  1. 45 CFR 1100.4 - Current index.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Current index. 1100.4 Section 1100.4 Public... INFORMATION § 1100.4 Current index. Each agency shall maintain and make available for public inspection and copying a current index providing identifying information for the public as to any matter which is issued...

  2. 12 CFR 1402.11 - Current index.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Current index. 1402.11 Section 1402.11 Banks... the Farm Credit System Insurance Corporation § 1402.11 Current index. The Farm Credit System Insurance Corporation will make available for public inspection and copying a current index to provide identifying...

  3. 45 CFR 502.6 - Current index.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Current index. 502.6 Section 502.6 Public Welfare..., DEPARTMENT OF JUSTICE RULES OF PRACTICE PUBLIC INFORMATION-FREEDOM OF INFORMATION ACT § 502.6 Current index. The Commission will maintain and make available for public inspection and copying, current indexes...

  4. 22 CFR 212.23 - Current index.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Current index. 212.23 Section 212.23 Foreign... Inspection and Copying § 212.23 Current index. USAID maintains and makes available for public inspection and copying a current index providing identifying information for the public as to any matter which has been...

  5. Superconducting current in a bisoliton superconductivity model

    International Nuclear Information System (INIS)

    Ermakov, V.N.; Kruchinin, S.P.; Ponezha, E.A.

    1991-01-01

    It is shown that the transition into a superconducting state with the current which is described by a bisoliton superconductivity model is accompanied by the deformation of the spectrum of one-particle states of the current carriers. The deformation value is proportional to the conducting current force. The residuaby resistance in such state is absent

  6. Improving sensitivity of residual current transformers to high frequency earth fault currents

    Directory of Open Access Journals (Sweden)

    Czapp Stanislaw

    2017-09-01

    Full Text Available For protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed the modification in the structure of residual current devices. This modification improves sensitivity of residual current devices when high frequency earth fault current occurs. The test of the modified residual current device proved that the authors’ proposition is appropriate.

  7. Review of current drive theory: selected topics

    International Nuclear Information System (INIS)

    Fisch, N.J.

    1993-01-01

    Two themes in current drive theory in tokamaks are reviewed, both relevant to the progression of tokamak experiments toward the reactor regime. First, the physics of the tail electrons is reviewed. These electrons are capable of carrying enormous rf-driven electric current, and, in the course of current-drive experiments worldwide not only has the current drive effect been demonstrated, but the underlying physical description of these tail electrons has been established. Second, anticipating the presence of the energetic alpha particles that result from D-T reactions in a reactor, certain mechanisms through which these alpha particles can be used to facilitate current-drive are reviewed. (Author)

  8. Spin-zero mesons and current algebras

    International Nuclear Information System (INIS)

    Wellner, M.

    1977-01-01

    Large chiral algebras, using the f and d coefficients of SU(3) can be constructed with spin-1/2 baryons. Such algebras have been found useful in some previous investigations. This article examines under what conditions similar or identical current algebras may be realized with spin-0 mesons. A curious lack of analogy emerges between meson and baryon currents. Second-class currents, made of mesons, are required in some algebras. If meson and baryon currents are to satisfy the same extended SU(3) algebra, four meson nonets are needed, in terms of which we give an explicit construction for the currents

  9. Ohm's law for a current sheet

    Science.gov (United States)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  10. Critical current in nonhomogeneous YBCO coated conductors

    International Nuclear Information System (INIS)

    Rostila, L; Mikkonen, R; Lehtonen, J

    2008-01-01

    The critical current of an YBCO tape is determined by the magnetic field inside the YBCO layer and the quality of YBCO material. In thick YBCO layers the average critical current density is reduced by the self-field and decreased material quality. In this paper the combined influence of the material nonhomogeneities and self-field on the critical current of YBCO tapes is scrutinised. First, the zero field critical current density was assumed to decrease along the YBCO thickness. Secondly, the possible defects created in the cutting of YBCO tapes were modelled as a function of lowered critical current density near the tape edges. In both cases the critical current was computed numerically with integral element method. The results suggest that the variation of zero field critical current density, J c0 , along the tape thickness does not effect on the critical current if the mean value of J c0 is kept constant. However, if J c0 is varied along the tape width the critical current can change due to the variated self-field. The computations can be used to determine when it is possible to evaluate the average zero field critical current density from a voltage-current measurement with an appropriate accuracy

  11. Radiofrequency contact currents: sensory responses and dosimetry

    International Nuclear Information System (INIS)

    Kavet, Robert; Tell, R.A.; Olsen, R.G.

    2014-01-01

    The process of setting science-based exposure standards (or guidelines) for radiofrequency (RF) contact current exposure has been disadvantaged by a lack of relevant data. The authors first review the essential features and results of the available studies and illustrate the apparent discrepancies among them. Then, they examine the manner in which current was administered in these studies and suggest as to how the physical relationship of a contacting finger to the current electrode may play a role in affecting sensory thresholds specific to those configurations. A major factor in this analysis relates to whether current density is uniformly distributed across the contact area or whether an electrode's 'edge effects' enhance currents with a net effect of decreasing apparent thresholds, when expressed as the bulk current entering a subject. For an exposure with a clear hazard potential, thresholds of human sensory response to RF currents require further investigation. (authors)

  12. X-ray tube current control

    International Nuclear Information System (INIS)

    Dupuis, W.A.; Resnick, T.A.

    1982-01-01

    A closed loop feedback system for controlling the current output of an x-ray tube. The system has circuitry for improving the transient response and stability of the x-ray tube current over a substantial nonlinear portion of the tube current production characteristic. The system includes a reference generator for applying adjustable step function reference signals representing desired tube currents. The system also includes means for instantaneous sensing of actual tube current. An error detector compares the value of actual and reference tube current and produces an error signal as a function of their difference. The system feedback loop includes amplification circuitry for controlling x-ray tube filament dc voltage to regulate tube current as a function of the error signal value. The system also includes compensation circuitry, between the reference generator and the amplification circuitry, to vary the loop gain of the feedback control system as a function of the reference magnitude

  13. The halo current in ASDEX Upgrade

    International Nuclear Information System (INIS)

    Pautasso, G.; Giannone, L.; Gruber, O.; Herrmann, A.; Maraschek, M.; Schuhbeck, K.H.

    2011-01-01

    Due to the complexity of the phenomena involved, a self-consistent physical model for the prediction of the halo current is not available. Therefore the ITER specifications of the spatial distribution and evolution of the halo current rely on empirical assumptions. This paper presents the results of an extensive analysis of the halo current measured in ASDEX Upgrade with particular emphasis on the evolution of the halo region, on the magnitude and time history of the halo current, and on the structure and duration of its toroidal and poloidal asymmetries. The effective length of the poloidal path of the halo current in the vessel is found to be rather insensitive to plasma parameters. Large values of the toroidally averaged halo current are observed in both vertical displacement events and centred disruptions but last a small fraction of the current quench; they coincide typically with a large but short-lived MHD event.

  14. The halo current in ASDEX Upgrade

    Science.gov (United States)

    Pautasso, G.; Giannone, L.; Gruber, O.; Herrmann, A.; Maraschek, M.; Schuhbeck, K. H.; ASDEX Upgrade Team

    2011-04-01

    Due to the complexity of the phenomena involved, a self-consistent physical model for the prediction of the halo current is not available. Therefore the ITER specifications of the spatial distribution and evolution of the halo current rely on empirical assumptions. This paper presents the results of an extensive analysis of the halo current measured in ASDEX Upgrade with particular emphasis on the evolution of the halo region, on the magnitude and time history of the halo current, and on the structure and duration of its toroidal and poloidal asymmetries. The effective length of the poloidal path of the halo current in the vessel is found to be rather insensitive to plasma parameters. Large values of the toroidally averaged halo current are observed in both vertical displacement events and centred disruptions but last a small fraction of the current quench; they coincide typically with a large but short-lived MHD event.

  15. Low-Frequency Pulsed Current Versus Kilohertz-Frequency Alternating Current: A Scoping Literature Review.

    Science.gov (United States)

    Vaz, Marco Aurélio; Frasson, Viviane Bortoluzzi

    2018-04-01

    To compare the effectiveness of low-frequency pulsed current versus kilohertz-frequency alternating current in terms of evoked force, discomfort level, current intensity, and muscle fatigability; to discuss the physiological mechanisms of each neuromuscular electrical stimulation type; and to determine if kilohertz-frequency alternating current is better than low-frequency pulsed current for clinical treatment. Articles were obtained from PubMed, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, and SPORTSDiscus databases using the terms Russian current or kilohertz current or alternating current or pulsed current or Aussie current and torque or discomfort or fatigue or current intensity, and through citation tracking up to July 2017. Two independent reviewers selected studies comparing the use of the 2 neuromuscular electrical stimulation currents. Studies describing maximal current intensity tolerated and the main effects of the 2 different current types on discomfort, muscle force, and fatigability were independently reviewed. Data were systematized according to (1) methodology; (2) electrical current characteristics; and (3) outcomes on discomfort level, evoked force, current intensity, and muscle fatigability. The search revealed 15 articles comparing the 2 current types. Kilohertz-frequency alternated current generated equal or less force, similar discomfort, similar current intensity for maximal tolerated neuromuscular electrical stimulation, and more fatigue compared with low-frequency pulsed current. Similar submaximal levels of evoked force revealed higher discomfort and current intensity for kilohertz-frequency alternated current compared with low-frequency pulsed current. Available evidence does not support the idea that kilohertz-frequency alternated current is better than low-frequency pulsed current for strength training and rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier

  16. Analytic modeling of axisymmetric disruption halo currents

    International Nuclear Information System (INIS)

    Humphreys, D.A.; Kellman, A.G.

    1999-01-01

    Currents which can flow in plasma facing components during disruptions pose a challenge to the design of next generation tokamaks. Induced toroidal eddy currents and both induced and conducted poloidal ''halo'' currents can produce design-limiting electromagnetic loads. While induction of toroidal and poloidal currents in passive structures is a well-understood phenomenon, the driving terms and scalings for poloidal currents flowing on open field lines during disruptions are less well established. A model of halo current evolution is presented in which the current is induced in the halo by decay of the plasma current and change in enclosed toroidal flux while being convected into the halo from the core by plasma motion. Fundamental physical processes and scalings are described in a simplified analytic version of the model. The peak axisymmetric halo current is found to depend on halo and core plasma characteristics during the current quench, including machine and plasma dimensions, resistivities, safety factor, and vertical stability growth rate. Two extreme regimes in poloidal halo current amplitude are identified depending on the minimum halo safety factor reached during the disruption. A 'type I' disruption is characterized by a minimum safety factor that remains relatively high (typically 2 - 3, comparable to the predisruption safety factor), and a relatively low poloidal halo current. A 'type II' disruption is characterized by a minimum safety factor comparable to unity and a relatively high poloidal halo current. Model predictions for these two regimes are found to agree well with halo current measurements from vertical displacement event disruptions in DIII-D [T. S. Taylor, K. H. Burrell, D. R. Baker, G. L. Jackson, R. J. La Haye, M. A. Mahdavi, R. Prater, T. C. Simonen, and A. D. Turnbull, open-quotes Results from the DIII-D Scientific Research Program,close quotes in Proceedings of the 17th IAEA Fusion Energy Conference, Yokohama, 1998, to be published in

  17. Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

    2015-01-01

    This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...

  18. Fault current limiter using bulk oxides superconductors

    International Nuclear Information System (INIS)

    Belmont, O.; Ferracci, P.; Porcar, L.; Barbut, J.M.; Tixador, P.; Noudem, J.G.; Bourgault, D.; Tournier, R.

    1998-01-01

    We study the limitation possibilities of bulk Bi high T c materials. For this we test these materials with AC or DC currents above their critical currents. We study particularly the evolution of the voltage with time or with current. The material, the value of the current and the time duration play important parts. For sintered Bi samples the voltage depends only on the current even for values much larger than the critical current. With textured samples the V(I) curves shows an hysteretic behaviour due to a warming up. The textured materials are more interesting than sintered ones in terms of required volume for the current limitation. In both cases the superconductors are in a dissipative state but not in the normal state. This state is nevertheless reached if the dissipated energy inside the sample is sufficient. We have tried to apply a magnetic field on the samples in order to trigger a more effective limitation. The voltage increases but with a limited effect for currents much higher (3-4 times) than the critical zero field current. We think that the dissipative state is due mainly to the grain boundaries which become resistive above the critical current. (orig.)

  19. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    OBJECTIVE: The aim of this study was to investigate whether bipolar pacemaker current lead can activate blood platelets. The null hypothesis was that 1 minute of electrical stimulation of platelets would not influence their subsequent reactivity to adenosine diphosphate (ADP). BACKGROUND: Both...... platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets......, to the depolarizing current. Platelet activation may ensue, resulting in aggregation, release reaction, and contraction. In contrast, a unipolar pacemaker system will not depolarize blood, but transmit current directly into the myocardium, and the current afterward passes through other tissues before returning...

  20. Return currents in solar flares - Collisionless effects

    Science.gov (United States)

    Rowland, H. L.; Vlahos, L.

    1985-01-01

    If the primary, precipitating electrons in a solar flare are unstable to beam plasma interactions, it is shown that strong Langmuir turbulence can seriously modify the way in which a return current is carried by the background plasma. In particular, the return (or reverse) current will not be carried by the bulk of the electrons, but by a small number of high velocity electrons. For beam/plasma densities greater than 0.01, this can reduce the effects of collisions on the return current. For higher density beams where the return current could be unstable to current driven instabilities, the effects of strong turbulence anomalous resistivity is shown to prevent the appearance of such instabilities. Again in this regime, how the return current is carried is determined by the beam generated strong turbulence.