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Sample records for axial-vector currents

  1. An Unbroken Axial Vector Current Conservation Law

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2015-01-01

    The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space i...

  2. New Anomaly of the Axial-Vector Current

    Institute of Scientific and Technical Information of China (English)

    HE Han-Xin

    2001-01-01

    By computing the axial-vector current operator equation, we find the anomalous axial-vector curl equation besides the well-known anomalous axial-vector divergence equation (the Adler-Bell-Jackiw anomaly) and discuss its implication.``

  3. Improving the lattice axial vector current

    CERN Document Server

    Horsley, R; Perlt, H; Rakow, P E L; Schierholz, G; Schiller, A; Zanotti, J M

    2015-01-01

    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.

  4. An Unbroken Axial-Vector Current Conservation Law

    Science.gov (United States)

    Sharafiddinov, Rasulkhozha S.

    2016-04-01

    The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space in which a neutrino is characterized by left as well as by right space-time coordinates. Therefore, it is not surprising that whatever the main purposes experiments about a quasielastic axial-vector mass say in favor of an axial-vector mirror Minkowski space-time.

  5. Chiral structure of vector and axial-vector tetraquark currents

    International Nuclear Information System (INIS)

    We investigate the chiral structure of local vector and axial-vector tetraquark currents, and study their chiral transformation properties. We consider the charge-conjugation parity and classify all the isovector vector and axial-vector local tetraquark currents of quantum numbers IG JPC =1-1-+, IG JPC =1+1--, IG JPC = 1-1++ and IG JPC = 1+1+-. We find that there is a one to one correspondence among them. Using these currents, we perform QCD sum rule analyses. Our results suggest that there is a missing b1 state having IG JPC =1+1+- and a mass around 1.47-1.66 GeV. (orig.)

  6. One-loop corrections to the baryon axial vector current

    Indian Academy of Sciences (India)

    M A Hernández-Ruíz

    2012-10-01

    The symmetry breaking corrections to the pion–baryon couplings vanish to first order in $1/N_{c}$, where $N_{c}$ is the number of colours. Loop graphs with octet and decuplet intermediate states cancel to various orders in $N_{c}$ as a consequence of the large-$N_{c}$ spin-flavour symmetry of QCD baryons. The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large Nc limit. $1/N_{c}$ corrections in the case of $g_{A}$ in QCD are presented here.

  7. Renormalization of the baryon axial vector current in large-Nc chiral perturbation theory

    International Nuclear Information System (INIS)

    The baryon axial vector current is considered within the combined framework of large-Nc baryon chiral perturbation theory (where Nc is the number of colors) and the baryon axial vector couplings are extracted. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis

  8. Partially conserved axial-vector current and model chiral field theories in nuclear physics

    International Nuclear Information System (INIS)

    We comment on the relation between the two standard approaches to chiral symmetry--namely, the current algebra/partially conserved axial-vector current approach and the chiral Lagrangian method--in a manner intended to clarify recent and probable future applications of this symmetry in nuclear physics. Specifically, we show that in explicit chiral field theories the canonical πN scattering amplitude does not have the famed ''Adler zero'' unless partial conservation of axial-vector current holds as an operator equation. This implies that there are a number of familiar chiral models in which the ''Adler self-consistency'' condition does not apply to the canonical pion field. Among the problems of current interest for which our remarks are relevant are the studies of the pion-nucleus optical potential, pion condensation, and the attempts to formulate a model field theory having both reasonable nuclear saturation and good low energy pion phenomenology

  9. Universal formula for the flavor non-singlet axial-vector current from the gradient flow

    International Nuclear Information System (INIS)

    By employing the gradient/Wilson flow, we derive a universal formula that expresses a correctly normalized flavor non-singlet axial-vector current of quarks. The formula is universal in the sense that it holds independently of regularization and especially holds with lattice regularization. It is also confirmed that, in the lowest non-trivial order of perturbation theory, the triangle diagram containing the formula and two flavor non-singlet vector currents possesses non-local structure that is compatible with the triangle anomaly

  10. Axial-vector current and quark spin content of the proton in an effective theory

    International Nuclear Information System (INIS)

    The background field theory is applied to study the internal spin structure of the proton in terms of both the large Nc expansion and derivative expansion. A new flavor-independent axial-vector current has been derived. Due to the higher order of this current in the large Nc expansion and the higher order in the derivative expansion a small quark spin content is expected and a nonzero strange quark spin content is revealed from the large Nc expansion. The numerical results are in agreement with the data. (orig.)

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

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Jing

    2009-01-01

    Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axialvector 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 P/μe< 10~7 g/cm~3).Thus the rates of the axial-vector contribution cannot be neglected.On the other hand, the rates of the axialvector 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 p/μe>10~7 g/cm~3) and a temperature of T≤10~(11) K.

  12. Extended partially conserved axial-vector current hypothesis and chiral-symmetry breaking

    International Nuclear Information System (INIS)

    An extended partially conserved axial-vector current (PCAC) hypothesis that incorporates a family of heavy bosons in a model-independent way is proposed. This is motivated by the impossibility of accounting for the corrections to Goldberger-Treiman relations, both in SU(2) x SU(2) and SU(3) x SU(3), by means of ordinary dynamical mechanisms (many-particle intermediate states). This new hypothesis coupled with an assumption on the strong-coupling constants of the heavy bosons leads to the following results: (i) A universality among the corrections to Goldberger-Treiman relations for ΔS = 0 decays, Δ/sub π/, on the one hand and for ΔS not-equal 0 decays, Δ/sub K/, on the other. (ii) From this universality there follow two sets of sum rules involving masses and strong and weak coupling constants. These sum rules become identities in the chiral as well as in the SU(3) limit and although a definite check has to await for the advent of accurate hyperon data, there are indications that they might be saturated. (iii) By studying the Dashen-Weinstein sum rules, new sets of sum rules involving only strong coupling constants are predicted as well as an expression for Δ/sub π//Δ/sub K/ in good agreement with present data. (iv) It is found that Δ/sub π/ and Δ/sub K/, which are a measure of chiral-symmetry breaking, determine completely the on-mass-shell corrections to soft-meson theorems. Since both Δ/sub π/ and Δ/sub K/ are known experimentally, a calculation is made of the on-mass-shell amplitudes for π0 → γγ, eta → γγ, eta → ππγ, γ → πππ,and γγ → πππ starting from the zero-mass limits implied by anomalous Ward identities. In particular, it is found that the results for the radiative eta decays are in agreement with present experimental data without the need for invoking eta-eta' mixing

  13. Pion electroproduction, partially conserved axial-vector current, chiral Ward identities, and the axial form factor revisited

    International Nuclear Information System (INIS)

    We reinvestigate Adler's partially conserved axial-vector current relation in the presence of an external electromagnetic field within the framework of QCD coupled to external fields. We discuss pion electroproduction within a tree-level approximation to chiral perturbation theory and explicitly verify a chiral Ward identity referred to as the Adler-Gilman relation. We critically examine soft-momentum techniques and point out how inadmissable approximations may lead to results incompatible with chiral symmetry. As a result we confirm that threshold pion electroproduction is indeed a tool to obtain information on the axial form factor of the nucleon

  14. 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.

  15. 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)

    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 mqk through use of the quark-condensate component of the nonperturbative fermion propagator. The result obtained is analytic in p2 except for a branch cut for 02qk)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 mqk 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.)

  16. Currents and energy-momentum tensor in the chiral Schwinger model with general vector and axial-vector couplings

    International Nuclear Information System (INIS)

    Using the point-splitting procedure and the method of functional integration, we define currents in the chiral Schwinger model and compute the correlation funtions of currents with themselves and with the fundamental fields. We show that the ambiguities in the choice of the phase factor employed in the point-splitting procedure can be compensated by mixing of the currents with the gauge potential Aμ and εμνAν. A three-parameter family of conserved currents is found and the transformations they generate are identified. In order to construct the conserved energy-momentum tensor, it is necessary to allow for mixings with AμAν and gμνAαAα. We compute the two-point function of the energy-momentum tensor and the correlation functions of it with the fundamental fields. The physics of the chiral model is discussed in comparison with the vector model

  17. Strange axial-vector mesons

    International Nuclear Information System (INIS)

    The strange axial-vector mesons K1 (1270) and K1 (1400) are reanalyzed in the light of the updated experimental information and compared with the recent result on the Kππ production in τ decay. The mixing angle between the strange mesons of 3P1 and 1P1 is determined by the partial decay rates, and, independently, by the masses. They lead to θK∼33 degree or 57 degree. The observed K1 (1400) production dominance in the τ decay favors θK∼33 degree. Flavor-SU(3) breaking of 20% or so in the production amplitudes can explain quantitatively the observed production ratio

  18. Axial Vector $Z'$ and Anomaly Cancellation

    CERN Document Server

    Ismail, Ahmed; Tsao, Kuo-Hsing; Unwin, James

    2016-01-01

    Whilst the prospect of new $Z'$ gauge bosons with only axial couplings to the Standard Model (SM) fermions is widely discussed, examples of anomaly-free renormalisable models are lacking in the literature. We look to remedy this by constructing several motivated examples. Specifically, we consider axial vectors which couple universally to all SM fermions, as well as those which are generation-specific, leptophilic, and leptophobic. Anomaly cancellation typically requires the presence of new coloured and charged chiral fermions, and we argue that the masses of these new states must generally be comparable to that of the axial vector. Finally, an axial vector mediator could provide a portal between SM and hidden sector states, and we also consider the possibility that the axial vector couples to dark matter. If the dark matter relic density is set due to freeze-out via the axial vector, this strongly constrains the parameter space.

  19. Chiral symmetry restoration and axial vector renormalization for Wilson fermions

    CERN Document Server

    Reisz, T

    2000-01-01

    Lattice gauge theories with Wilson fermions break chiral symmetry. In theU(1) axial vector current this manifests itself in the anomaly. On the otherhand it is generally expected that the axial vector flavour mixing current isnon-anomalous. We give a short, but strict proof of this to all orders ofperturbation theory, and show that chiral symmetry restauration implies aunique multiplicative renormalization constant for the current. This constantis determined entirely from an irrelevant operator in the Ward identity. Thebasic ingredients going into the proof are the lattice Ward identity, chargeconjugation symmetry and the power counting theorem. We compute therenormalization constant to one loop order. It is largely independent of theparticular lattice realization of the current.

  20. An Axial Vector Photon in a Mirror World

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2015-01-01

    The unity of symmetry laws emphasizes, in the case of a mirror CP-even Dirac Lagrangian, the ideas of the left- and right-handed axial-vector photons referring to long- and short-lived bosons of true neutrality, respectively. Such a difference in lifetimes expresses the unidenticality of masses, energies and momenta of axial-vector photons of the different components. They define the unified field theory equation of C-odd particles with an integral spin. Together with a new equation of a theory of truly neutral particles with the half-integral spin, the latter reflects the availability in their nature of the second type of the local axial-vector gauge transformation responsible for origination in the Lagrangian of C-oddity of an interaction Newton component giving an axial-vector mass to all the interacting particles and fields. The mirror axial-vector mass, energy and momentum operators constitute a CP-invariant equation of quantum mechanics, confirming that each of them can individually influence on matter ...

  1. An Axial-Vector Photon in a Mirror World

    Science.gov (United States)

    Sharafiddinov, Rasulkhozha S.

    2016-03-01

    The unity of symmetry laws emphasizes, in the case of a mirror CP-even Dirac Lagrangian, the ideas of the left- and right-handed axial-vector photons referring to long- and short-lived bosons of true neutrality, respectively. Such a difference in lifetimes expresses the unidenticality of masses, energies and momenta of axial-vector photons of the different components. They define the unified field theory equation of C-odd particles with an integral spin. Together with a new equation of a theory of truly neutral particles with the half-integral spin, the latter reflects the availability in their nature of the second type of the local axial-vector gauge transformation responsible for origination in the Lagrangian of C-oddity of an interaction Newton component giving an axial-vector mass to all the interacting particles and fields. The mirror axial-vector mass, energy and momentum operators constitute a CP-invariant equation of quantum mechanics, confirming that each of them can individually influence on matter field. Thereby, findings suggest at the level of the mass-charge structure of gauge invariance a new equation for the C-noninvariant Lagrangian.

  2. Ward-Takahashi identities for the radiative axial-vector vertex and low-energy theorem for the pion electroproduction

    International Nuclear Information System (INIS)

    Using the assumption of a partially conserved axial-vector current and the conservation law for the electromagnetic current, we rederive a low-energy theorem for the pion electroproduction. In contrast to the traditional approach, we include all effects of off-shell nucleons and pions. We parametrize the axial-vector current in its most general form and apply the minimal substitution prescription to obtain the radiative axial-vector vertex that is required for gauge invariance. We split the full radiative axial-vector vertex into the isolated-pole contribution, the minimal-coupling interaction, and the remainder. The Ward-Takahashi identities are translated into the constraints on the pion electroproduction amplitude. The rigorous low-energy theorem is obtained for the zero four-momentum pion electroproduction. It is found that the off-shell matrix elements of the axial-vector current affect the isolated-pole term and the gauge term so that the low-energy theorem is at variance with the standard one given in the literature

  3. Modified approach for calculating axial vector vacuum susceptibility

    International Nuclear Information System (INIS)

    We generalize our previous work [Phys. Rev. C 72, 035202 (2005)] on the linear response theory of the dressed quark propagator in the presence of a constant external field to the case of a variable external field in order to make it applicable to a wider class of problems. Using the axial vector vacuum susceptibility as an illustration, we apply this general formalism to extract a new expression for the axial vector vacuum susceptibility in the quantum chromodynamical (QCD) sum rule two-point external field formula. The numerical values of the axial vector vacuum susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison with the results of the previous approaches is given

  4. Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

    CERN Document Server

    Gran, R; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pappagallo, M; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, Yu K; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, C; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Willocq, S Y; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Potter, C T; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Del Re, D; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Mayer, B; Vasseur, G; Yéche, C; Zito, M; Park, W; Purohit, M V; Weidemann, A W; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Boyarski, A M; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Azzolini, V; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihályi, A; Mohapatra, A K; Pan, Y; Pierini, M; Prepost, R; Tan, P; Wu, S L; Yu, Z; Neal, H; Back, B B

    2006-01-01

    The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \\pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.

  5. Nucleon's axial-vector form factor in the hard-wall AdS/QCD model

    CERN Document Server

    Mamedov, Shahin; Huseynova, Narmin; Atayev, Ibrahim

    2016-01-01

    The axial-vector form factor of the nucleons is considered in the framework of hard-wall model of holographic QCD. A new interaction term between the bulk gauge and matter fields was included into the interaction Lagrangian. We obtain the axial-vector form factor of nucleons in the boundary QCD from the bulk action using AdS/CFT correspondence. The momentum square dependence of the axial-vector form factor is analysed numerically.

  6. Sum rule analysis of vector and axial-vector spectral functions with excited states in vacuum

    OpenAIRE

    Hohler, Paul M.; Rapp, Ralf

    2012-01-01

    We simultaneously analyze vector and axial-vector spectral functions in vacuum using hadronic models constrained by experimental data and the requirement that Weinberg-type sum rules are satisfied. Upon explicit inclusion of an excited vector state, viz. rho', and the requirement that the perturbative continua are degenerate in vector and axial-vector channels, we deduce the existence of an excited axial-vector resonance state, a1', in order that the Weinberg sum rules are satisfied. The resu...

  7. Thermal behavior of the axial vector coupling constant

    International Nuclear Information System (INIS)

    A thermal QCD Finite Energy Sum Rule (FESR) allows us to obtain the temperature dependence of the axial vector coupling of the nucleon, gA(T). It turns out that this coupling is essentially constant for the wide range 0 ≤ T ≤ 0.9Tc, being Tc the critical deconfining temperature. In contrast to other effective hadronic couplings, gA(T) diverges when T → Tc. At finite temperature, gA develops also a q2 dependence. This led us to explore the mean squared radius associated to gA, finding that it diverges at the critical temperature, thus signalling quark deconfinement. Finally, as a byproduct of our analysis, we study the thermal evolution of the Goldberger-Treiman relation

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

    International Nuclear Information System (INIS)

    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 Li. 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

  9. Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors

    CERN Document Server

    Deur, Alexandre

    2013-01-01

    We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01

  10. Pseudocalar meson and vector meson interactions and dynamically generated axial-vector mesons

    OpenAIRE

    Zhou, Yu; Ren, Xiu-Lei; Chen, Hua-Xing; Geng, Li-Sheng

    2014-01-01

    The axial-vector mesons $a_1(1260)$, $b_1(1235)$, $f_1(1285)$, $h_1(1170)$, $h_1(1380)$, and $K_1(1270)$ are dynamically generated in the unitized chiral perturbation theory. Such a picture has been tested extensively in the past few years. In this work, we calculate the interaction kernel up to $\\mathcal{O}(p^2)$ and study the impact on the dynamically generated axial-vector states. In anticipation of future lattice QCD simulations, we calculate the scattering lengths and the pole positions ...

  11. 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: 7.512, year: 2014

  12. Coupled-channel study of axial-vector mesons with realistic t- and u-channel exchanges

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Julian

    2010-02-17

    In this thesis, the significance of t- and u-channel exchange processes in the formation of axial-vector mesons is studied. The analysis is based on a chiral Lagrangian for light vector mesons. A non-linear integral equation based on unitarity and causality is used to unitarize the scattering amplitude. This leads to the formation of axial-vector molecules. (orig.)

  13. QCD sum rule analysis for light vector and axial-vector mesons in vacuum and nuclear matter

    OpenAIRE

    Leupold, Stefan

    2001-01-01

    Extending previous work we study the constraints of QCD sum rules on mass and width of light vector and axial-vector mesons in vacuum and in a medium with finite nuclear density. For the latter case especially the effect of nuclear pions leading to vector-axial-vector mixing is included in the analysis.

  14. Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors

    International Nuclear Information System (INIS)

    We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q2 dependence of the axial-vector form factor ga(Q2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure ga(Q2). If ga(Q2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q2 mapping of ga between 0.01 22. 60 days of beam can yield 14 data points with a subpercent statistical and point to point uncorrelated uncertainties on each point. Such an experiment may also allow to measure the free-neutron magnetic form factor GMn. The experiment employs the usual techniques of electron-nucleon scattering and presents no special difficulty. Higher energy extensions are possible. They could yield measurements of ga(Q2) up to Q2=3 GeV2 and the possibility to access other form factors, such as the almost unknown pseudoscalar form factor gP. However, the experiments become much more challenging as soon as beam energies pass the pion production threshold

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

    CERN Document Server

    Agaev, S S; Barsbay, B; Sundu, H

    2016-01-01

    The mass and meson-current coupling constant of the resonance $X(5568)$, as well as the width of the decay $X(5568)\\to B_s^{\\ast}\\pi$ are calculated by modeling the exotic $X(5568)$ resonance as a diquark-antidiquark state $% X_b=[su][bd]$ with quantum numbers $J^{P}=1^{+}$. 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 $X_bB_{s}^{\\ast}\\pi$ and extract the strong coupling $g_{X_bB_{s}^{\\ast}\\pi}$, which is a necessary ingredient to find the width of the $X_b \\to B_s^{\\ast}\\pi^{+}$ decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.

  16. Ward–Green–Takahashi identities and the axial-vector vertex

    International Nuclear Information System (INIS)

    The colour-singlet axial-vector vertex plays a pivotal role in understanding dynamical chiral symmetry breaking and numerous hadronic weak interactions, yet scant model-independent information is available. We therefore use longitudinal and transverse Ward–Green–Takahashi (WGT) identities, together with kinematic constraints, in order to ameliorate this situation and expose novel features of the axial vertex: amongst them, Ward-like identities for elements in the transverse piece of the vertex, which complement and shed new light on identities determined previously for components in its longitudinal part. Such algebraic results are verified via solutions of the Bethe–Salpeter equation for the axial vertex obtained using two materially different kernels for the relevant Dyson–Schwinger equations. The solutions also provide insights that suggest a practical Ansatz for the axial-vector vertex.

  17. \\(\\tau\\) vector and axial-vector spectral functions in the extended linear sigma model

    CERN Document Server

    Habersetzer, A

    2015-01-01

    The extended linear sigma model describes the vacuum phenomenology of scalar, pseudoscalar, vector and axial-vector mesons at energies \\(\\simeq 1\\text{ GeV}\\). We combine the chiral \\(U(2)_L\\times U(2)_R\\) symmetry of this model with a local \\(SU(2)_L\\times U(1)_Y\\) symmetry and obtain a gauge invariant effective description for electroweak interaction of hadrons in the vacuum. Vector and axial-vector spectral functions can be described well by two intermediate resonances \\(\\rho\\) and \\(a_1\\). They are implemented into this model as chiral partners and yield the predominant contributions to both spectral functions. However, the contributions that arise from the non-resonant decay channels of the weak charged \\(W\\) bosons are essential for reproducing the lineshapes of the spectral functions.

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

    International Nuclear Information System (INIS)

    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 [Q2=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 [Q2 = 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

  19. Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State

    CERN Document Server

    Pham, T N

    2013-01-01

    The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. Therefore, if the pion is to be treated as a $q\\bar{q}$ bound state, this bound state would be a longitudinal axial-vector meson. In this paper, we consider the pion to be a longitudinal axial-vector meson $q\\bar{q}$ state with derivative coupling for the pion-$q\\bar{q}$ Bethe-Salpeter(BS) amplitude. We shall show that, the longitudinal axial-vector meson solution for the pion $q\\bar{q}$ Bethe-Salpeter wave function could produce a suppressed $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude in the soft pion limit, in agreement with t...

  20. Scalar mesons in a linear sigma model with (axial-)vector mesons

    CERN Document Server

    Parganlija, D; Wolf, Gy; Giacosa, F; Rischke, D H

    2012-01-01

    The structure of the scalar mesons has been a subject of debate for many decades. In this work we look for $\\bar{q}q$ states among the physical resonances using an extended Linear Sigma Model that contains scalar, pseudoscalar, vector, and axial-vector mesons both in the non-strange and strange sectors. We perform global fits of meson masses, decay widths and amplitudes in order to ascertain whether the scalar $\\bar{q}q$ states are below or above 1 GeV. We find the scalar states above 1 GeV to be preferred as $\\bar{q}q$ states.

  1. A U(4)r x U(4)l linear sigma model with (axial-)vector mesons

    International Nuclear Information System (INIS)

    We present a linear sigma model with U(4)r x U(4)l global chiral symmetry, which in addition to scalar and pseudoscalar mesons also includes vector and axial-vector mesons. Apart from three new parameters pertaining to the charm degree of freedom, the parameters of the model are fixed from the Nf = 3 flavor sector. Our results for the charmed meson masses and weak decay constants are in surprisingly good agreement with experimental data, with the marked exception of the scalar degrees of freedom, providing an indication that these states may not adhere to the standard quark-antiquark picture of a meson.

  2. Evaluation of the Axial Vector Commutator Sum Rule for Pion-Pion Scattering

    CERN Document Server

    Adler, Stephen L

    2007-01-01

    We consider the sum rule proposed by one of us (SLA), obtained by taking the expectation value of an axial vector commutator in a state with one pion. The sum rule relates the pion decay constant to integrals of pion-pion cross sections, with one pion off the mass shell. We remark that recent data on pion-pion scattering allow a precise evaluation of the sum rule. We also discuss the related Adler--Weisberger sum rule (obtained by taking the expectation value of the same commutator in a state with one nucleon), especially in connection with the problem of extrapolation of the pion momentum off its mass shell.

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

    CERN Document Server

    Liu, J; Holley, A T; Back, H O; Bowles, T J; Broussard, L J; Carr, R; Clayton, S; Currie, S; Filippone, B W; Garcia, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Hona, B; Ito, T M; Liu, C -Y; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Morris, C L; Pattie, R W; Galvan, A Perez; Pitt, M L; Plaster, B; Ramsey, J C; Rios, R; Russell, R; Saunders, A; Seestrom, S; Sondheim, W E; Tatar, E; Vogelaar, R B; VornDick, B; Wrede, C; Yan, H; Young, A R

    2010-01-01

    A precise measurement of the neutron decay $\\beta$-asymmetry $A_0$ has been carried out using polarized ultracold neutrons (UCN) from the pulsed spallation UCN source at the Los Alamos Neutron Science Center (LANSCE). Combining data obtained in 2008 and 2009, we report $A_0 = -0.11966 \\pm 0.00089 _{-0.00140}^{+0.00123}$, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon $g_A/g_V = -1.27590 _{-0.00445}^{+0.00409}$.

  4. Determination of the axial-vector weak coupling constant with ultracold neutrons.

    Science.gov (United States)

    Liu, J; Mendenhall, M P; Holley, A T; Back, H O; Bowles, T J; Broussard, L J; Carr, R; Clayton, S; Currie, S; Filippone, B W; García, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Hona, B; Ito, T M; Liu, C-Y; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Morris, C L; Pattie, R W; Pérez Galván, A; Pitt, M L; Plaster, B; Ramsey, J C; Rios, R; Russell, R; Saunders, A; Seestrom, S J; Sondheim, W E; Tatar, E; Vogelaar, R B; VornDick, B; Wrede, C; Yan, H; Young, A R

    2010-10-29

    A precise measurement of the neutron decay β asymmetry A₀ 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 A₀ = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}. PMID:21231098

  5. SU(3)--Breaking Effects in Axial--Vector Couplings of Octet Baryons

    CERN Document Server

    Gensini, P M; Gensini, Paolo M.; Violini, Galileo

    1993-01-01

    Present evidence on baryon axial--vector couplings is reviewed, the main emphasis being on internal consistency between asymmetry and rate data. A complete account of all {\\sl small} terms in the Standard Model description of these latter leads to {\\sl both} consistency {\\sl and} evidence for breaking of flavour SU(3) in the axial couplings of octet baryons. Talk presented at "5th Int. Sympos. on Meson--Nucleon Physics and the Structure of the Nucleon", Boulder, CO, sept. 1993. To be published in $\\pi N$ Newsletter.

  6. Pseudoscalar glueball, the axial-vector anomaly, and the mixing problem for pseudoscalar mesons

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, C.; Salomone, A.; Schechter, J.

    1981-11-01

    If the G(1440) observed in psi..--> gamma..G is a pseudoscalar glueball its relationship with other pseudoscalar mesons must be understood. We present a simple, unified picture of these mesons in which there must be mixing between glue matter and quark matter. Our model, an extension of an effective Lagrangian which solved the U(1) problem by incorporating the axial-vector anomaly, dictates a relationship between eta' and G. We are readily able to explain why the quark-matter meson eta' is at least as prominent as the glueball G in the gluon-dominated reaction psi..--> gamma..X.

  7. Axial vector transition form factors of N \\rightarrow \\Delta in QCD

    CERN Document Server

    Kucukarslan, A; Ozpineci, A

    2015-01-01

    The isovector axial vector form factors of N \\rightarrow \\Delta transition are calculated by employing Light-cone QCD sum rules. The analytical results are analysed by both the conventional method, and also by a Monte Carlo based approach which allows one to scan all of the parameter space. The predictions are also compared with the results in the literature, where available. Although the Monte Carlo analysis predicts large uncertainties in the predicted results, the predictions obtained by the conventional analysis are in good agreement with other results in the literature.

  8. Massive Yang-Mills for vector and axial-vector spectral functions at finite temperature

    Science.gov (United States)

    Hohler, Paul M.; Rapp, Ralf

    2016-05-01

    The hadronic mechanism which leads to chiral symmetry restoration is explored in the context of the ρπa1 system using Massive Yang-Mills, a hadronic effective theory which governs their microscopic interactions. In this approach, vector and axial-vector mesons are implemented as gauge bosons of a local chiral gauge group. We have previously shown that this model can describe the experimentally measured vector and axial-vector spectral functions in vacuum. Here, we carry the analysis to finite temperatures by evaluating medium effects in a pion gas and calculating thermal spectral functions. We find that the spectral peaks in both channels broaden along with a noticeable downward mass shift in the a1 spectral peak and negligible movement of the ρ peak. The approach toward spectral function degeneracy is accompanied by a reduction of chiral order parameters, i.e., the pion decay constant and scalar condensate. Our findings suggest a mechanism where the chiral mass splitting induced in vacuum is burned off. We explore this mechanism and identify future investigations which can further test it.

  9. 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.

  10. Functional Renormalization Group Study of the Chiral Phase Transition Including Vector and Axial-vector Mesons

    CERN Document Server

    Eser, Jürgen; Rischke, Dirk H

    2015-01-01

    The transition in quantum chromodynamics (QCD) from hadronic matter to the quark-gluon plasma (QGP) at high temperatures and/or net-baryon densities is associated with the restoration of chiral symmetry and can be investigated in the laboratory via heavy-ion collisions. We study this chiral transition within the functional renormalization group (FRG) approach applied to the two-flavor version of the extended Linear Sigma Model (eLSM). The eLSM is an effective model for the strong interaction and features besides scalar and pseudoscalar degrees of freedom also vector and axial- vector mesons. We discuss the impact of the quark masses and the axial anomaly on the order of the chiral transition. We also confirm the degeneracy of the masses of chiral partners above the transition temperature. We find that the mass of the $a_1$ meson ($\\rho$ meson) decreases (increases) towards the chiral transition.

  11. Functional renormalization group study of the chiral phase transition including vector and axial-vector mesons

    Science.gov (United States)

    Eser, Jürgen; Grahl, Mara; Rischke, Dirk H.

    2015-11-01

    The transition in quantum chromodynamics from hadronic matter to the quark-gluon plasma at high temperatures and/or net-baryon densities is associated with the restoration of chiral symmetry and can be investigated in the laboratory via heavy-ion collisions. We study this chiral transition within the functional renormalization group approach applied to the two-flavor version of the extended linear sigma model (eLSM). The eLSM is an effective model for the strong interaction and features besides scalar and pseudoscalar degrees of freedom also vector and axial-vector mesons. We discuss the impact of the quark masses and the axial anomaly on the order of the chiral transition. We also confirm the degeneracy of the masses of chiral partners above the transition temperature. We find that the mass of the a1 meson (ρ meson) decreases (increases) towards the chiral transition.

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

    International Nuclear Information System (INIS)

    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 (GA/GV)t = -1.2646 ± 0.0035

  13. Analysis of the Light-Flavor Scalar and Axial-Vector Diquark States with QCD Sum Rules

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-Gang

    2013-01-01

    In this article,we study the light-flavor scalar and axial-vector diquark states in the vacuum and in the nuclear matter using the QCD sum rules in a systematic way,and make reasonable predictions for their masses in the vacuum and in the nuclear matter.

  14. Vacuum effects in magnetic field with with account for fermion anomalous magnetic moment and axial-vector interaction

    Science.gov (United States)

    Bubnov, Andrey; Gubina, Nadezda; Zhukovsky, Vladimir

    2016-05-01

    We study vacuum polarization effects in the model of Dirac fermions with additional interaction of an anomalous magnetic moment with an external magnetic field and fermion interaction with an axial-vector condensate. The proper time method is used to calculate the one-loop vacuum corrections with consideration for different configurations of the characteristic parameters of these interactions.

  15. 77 FR 4853 - In the Matter of Airbee Wireless, Inc., Axial Vector Engine Corp. (n/k/a Avec Corporation), and...

    Science.gov (United States)

    2012-01-31

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION In the Matter of Airbee Wireless, Inc., Axial Vector Engine Corp. (n/k/a Avec Corporation), and... accurate information concerning the securities of Axial Vector Engine Corp. (n/k/a Avec...

  16. Photoproduction of the Theta^+ and its vector and axial-vector structure

    CERN Document Server

    Kim, Hyun-Chul; Ledwig, Tim; Nam, Seung-il

    2009-01-01

    We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU(3) chiral quark-soliton model, taking into account the 1/N_c rotational and linear m_s corrections. The main contribution to the electric-like transition form factor comes from the wave-function corrections. This is a consequence of the generalized Ademollo-Gatto theorem. It is also found that in general the leading-order contributions are almost canceled by the rotational 1/N_c corrections. The results are summarized as follows: the vector and tensor K^*-N-Theta coupling constants, g_{K^*-N-Theta}=0.74 - 0.87 and f_{K^*-N-Theta}=0.53 - 1.16, respectively, and Gamma_{Theta->KN}=0.71 MeV, based on the result of the K-N-Theta coupling constant g_{K-n-Theta}=0.83. We also show the differential cross sections and beam asymmetries, based on the present results. We also discuss the connection of present results with the original work by Diakonov, Petrov, and Polyakov.

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

    International Nuclear Information System (INIS)

    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 1320 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 π0 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

  18. Inclusive τ lepton hadronic decay in vector and axial-vector channels within dispersive approach to QCD

    International Nuclear Information System (INIS)

    The dispersive approach to QCD, which properly embodies the intrinsically nonperturbative constraints originating in the kinematic restrictions on relevant physical processes and extends the applicability range of perturbation theory towards the infrared domain, is briefly overviewed. The study of OPAL (update 2012) and ALEPH (update 2014) experimental data on inclusive τ lepton hadronic decay in vector and axial-vector channels within dispersive approach is presented

  19. Thermal Spectrum of Heavy Vector and Axial Vector Mesons in the Framework of QCD Sum Rules Method

    CERN Document Server

    Yazici, Enis

    2016-01-01

    The masses and the leptonic decay constants of vector and axial vector heavy-heavy mesons are calculated using the thermal QCD sum rules approach. While obtaining the QCD sum rules, additional operators in the Wilson expansion and also temperature dependency of the continuum threshold are taken into account. The masses and the decay constants remained unchanged up to $T\\simeq100~MeV$. After that point, they start to diminish. At the critical temperature, the masses decreased about $3\\%$, $5\\%$ and $14\\%$ for the vector mesons $\\Upsilon$, $B_{c}$ and $J/\\psi$; $6\\%$, $7\\%$ and $22\\%$ for the axial vector mesons $\\chi_{b1}$, $B_{c}$ and $\\chi_{c1}$, respectively. The decay constants reached about less than $20\\%$ of their vacuum values. The obtained results of the thermal mass and decay constant calculations at zero temperature are in a very good agreement with the other non-perturbative calculations at vacuum as well as with the experimental data.

  20. 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...

  1. Possible assignments of the $X(3872)$, $Z_c(3900)$ and $Z_b(10610)$ as axial-vector molecular states

    CERN Document Server

    Wang, Zhi-Gang

    2014-01-01

    In this article, we construct both the color singlet-singlet type and octet-octet type currents to interpolate the $X(3872)$, $Z_c(3900)$, $Z_b(10610)$, and calculate the vacuum condensates up to dimension-10 and order $\\mathcal{O}(\\alpha_s)$ in the operator product expansion. Then we study the axial-vector hidden charmed and hidden bottom molecular states with the QCD sum rules, explore the energy scale dependence of the QCD sum rules for the heavy molecular states in details, and use the formula $\\mu=\\sqrt{M^2_{X/Y/Z}-(2{\\mathbb{M}}_Q)^2}$ with the effective masses ${\\mathbb{M}}_Q$ to determine the energy scales. The numerical results support assigning the $X(3872)$, $Z_c(3900)$, $Z_b(10610)$ as the color singlet-singlet type molecular states with $J^{PC}=1^{++}$, $1^{+-}$, $1^{+-}$, respectively, more theoretical and experimental works are still needed to distinguish the molecule and tetraquark assignments; while there are no candidates for the color octet-octet type molecular states.

  2. Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV

    Energy Technology Data Exchange (ETDEWEB)

    G.S. Adams; T. Adams; Z. Bar-Yam; J.M. Bishop; V.A. Bodyagin; D.S. Brown; N.M. Cason; S.U. Chung; J.P. Cummings; K. Danyo; A.I. Demianov; S. Denisov; V. Dorofeev; J.P. Dowd; P. Eugenio; X.L. Fan; A.M. Gribushin; R.W. Hackenburg; M. Hayek; J. Hu; E.I. Ivanov; D. Joffe; I. Kachaev; W. Kern; E. King; O.L. Kodolova; V.L. Korotkikh; M.A. Kostin; Joachim Kuhn; V. Lipaev; J.M. Losecco; M. Lu; J.J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A.I. Ostrovidov; T.K. Pedlar; A. Popov; D. Ryabchikov; A.H. Sanjari; L.I. Sarycheva; K.K. Seth; N. Shenhav; X. Shen; W.D. Shephard; N.B. Sinev; D.L. Stienike; S.A. Taegar; D.R. Thompson; A. Tomaradze; I.N. Vardanyan; D.P. Weygand; D. White; H.J. Willutzki; A.A. Yershov

    2001-09-01

    The number of pseudoscalar mesons in the mass range from 1400 to 1500 MeV/c{sup 2} has been a subject of considerable interest for many years, with several experiments having presented evidence for two closely spaced states. A new measurement of the reaction {pi}{sup -} p {yields} K{sup +} K{sup -} {pi}{sup 0}n has been made at a beam energy of 18 GeV. A partial wave analysis of the K{sup +} K{sup -} {pi}{sup 0} system shows evidence for three pseudoscalar resonances, {eta}(1295), {eta}(1416), and {eta}(1485), as well as two axial vectors, f{sub 1}(1285), and f{sub 1}(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an I{sub G} J{sup PC} = 1{sup +} 1{sup --} state previously reported in {phi}{pi}{sup 0} decay.

  3. Interpreting f0(600) and a0(980) as \\bar q - q states from an Nf=3 Sigma Model with (Axial-)Vectors

    CERN Document Server

    Parganlija, Denis

    2011-01-01

    We address the question whether it is possible to interpret the low-lying scalar mesons f0(600) and a0(980) as \\bar q - q states within a U(3)xU(3) Linear Sigma Model containing vector and axial-vector degrees of freedom.

  4. Electroweak anomaly and current algebra for K → γlν

    International Nuclear Information System (INIS)

    The process K → γlν is calculated using the electroweak axial-vector anomaly with the quark color factor of 3, together with standard current-algebra techniques. The result, which generalizes that of Das, Mathur, and Okubo for the axial-vector part, is in good agreement with experiment

  5. Spatial modulation and topological current in holographic QCD matter

    OpenAIRE

    Fukushima, Kenji; Morales, Pablo

    2013-01-01

    We investigate an impact of the axial-vector interaction on spatial modulation of quark matter. A magnetic field coupled with baryon density leads to a topological axial current, so that the effect of the axial-vector interaction is crucially enhanced then. Using the Sakai-Sugimoto model we have found that, contrary to a naive expectation, the spatially modulated phase is less favored for a stronger magnetic field, which is realized by the presence of topological current.

  6. On the BRST and finite field dependent BRST of a model where vector and axial vector interaction get mixed up with different weight

    CERN Document Server

    Rahaman, Anisur

    2016-01-01

    The generalized version of a lower dimensional model where vector and axial vector interaction get mixed up with different weight is considered. The bosonized version of which does not posses the local gauge symmetry. An attempt has been made here to construct BRST invariant reformulation of this model using Batalin Fradlin and Vilkovisky formalism. It is found that the extra field needed to make it gauge invariant turns into Wess-Zumino scalar with appropriate choice of gauge fixing. An application of finite field dependent BRST and anti-BRST transformation is also made here in order to show the transmutation between the BRST symmetric and the usual non-symmetric version of the model.

  7. Relativistic center-of-mass variables and the harmonic oscillator quark model calculation of the nucleon magnetic moment and the axial-vector coupling constant

    Energy Technology Data Exchange (ETDEWEB)

    Ilakovac, A.; Tadic-acute-accent, D.D.; Coutinho, F.A.B.; Krmpotic-acute-accent, F.

    1986-04-15

    We study the introduction of the internal dynamical variables for consituent quarks. These variables are related to the center-of-mass of a nucleon. The problem is connected with the description of spinorial properties of the quarks. The spinors must be artificially introduced in a harmonic oscillator (HO) model. Experimental values of the magnetic moment and the axial-vector coupling constant of a nucleon can be easily reproduced. The theoretical results are not sensitive to the theoretical details; they follow from the general properties of the quark structure of baryons. The connections with the relativistic HO models are also discussed. The case of a very small confinement radius is explored in the Appendix.

  8. Relativistic center-of-mass variables and the harmonic oscillator quark model calculation of the nucleon magnetic moment and the axial-vector coupling constant

    International Nuclear Information System (INIS)

    We study the introduction of the internal dynamical variables for consituent quarks. These variables are related to the center-of-mass of a nucleon. The problem is connected with the description of spinorial properties of the quarks. The spinors must be artificially introduced in a harmonic oscillator (HO) model. Experimental values of the magnetic moment and the axial-vector coupling constant of a nucleon can be easily reproduced. The theoretical results are not sensitive to the theoretical details; they follow from the general properties of the quark structure of baryons. The connections with the relativistic HO models are also discussed. The case of a very small confinement radius is explored in the Appendix

  9. On the Poincar\\'e and Gauge symmetry of a model where vector and axial vector interaction get mixed up with different weight

    CERN Document Server

    Yasmin, Safia

    2016-01-01

    A $(1+1)$ dimensional model where vector and axial vector interaction get mixed up with different weight is considered with a generalized masslike term for gauge field. Through Poincar\\'e algebra it has been made confirm that only a Lorentz covariant masslike term leads to a physically sensible theory as long as the number of constraints in the phase space is two. With that admissible masslike term, phase space structure of this model with proper identification of physical canonical pair has been determined using Diracs' scheme of quantization of constrained system. The bosonized version of the model remains gauge non-invariant to start with. Therefore, with the inclusion of appropriate Wess-Zumino term it is made gauge symmetric. An alternative quantization has been carried out over this gauge symmetric version to determine the phase space structure in this situation. To establish that the Wess-Zumino fields allocates themselves in the un-physical sector of the theory an attempts has been made to get back th...

  10. Vector and axial currents in Wilson chiral perturbation theory

    International Nuclear Information System (INIS)

    We reconsider the construction of the vector and axial-vector currents in Wilson Chiral Perturbation Theory, the low-energy effective theory for lattice QCD with Wilson fermions. We discuss in detail the finite renormalization of the currents that has to be taken into account in order to properly match the currents. We explicitly show that imposing the chiral Ward identities on the currents does, in general, affect the axial-vector current at O(a). As an application of our results we compute the pion decay constant to one loop in the two-flavor theory. Our result differs from previously published ones.

  11. Neutral-current neutrino production of Δ (1236)

    International Nuclear Information System (INIS)

    We study the isovector vector and axial-vector neutral-current couplings by analyzing the neutral-current neutrino and antineutrino production of the Δ (1236) resonance. We use a quark model to predict the multipole structure and q2 dependence of the matrix elements. This model has been developed elsewhere for the charged-current case. We calculate and discuss relevant quantities: production cross sections as well as angular distribution of decay products. We show that measurable combinations of polarization density matrix elements are very sensitive to the relative magnitude and sign of the vector and axial-vector couplings. One can determine--up to an ambiguity--the vector and axial-vector couplings by measuring the neutrino and the antineutrino cross sections. The ambiguity can be solved by studying the angular distribution of the decay products. Moreover, both coupling could be determined also in a neutrino (or antineutrino) experiment alone by measuring the cross section and the polarization density matrix. Experiments must be performed at not too high energies, for which the vector-axial-vector interference term is sizeable. For pion neutrino production on nuclei, we point out that, if the recoil proton is observed, and if the π N mass is consistent with the Δ (1236) region, the nuclear charge-exchange corrections are lowered substantially with respect to the situation considered by Alder, Nussinov, and Paschos, in which only the pion is assumed to be observed

  12. Matching heavy-light currents with NRQCD and HISQ quarks

    OpenAIRE

    Monahan, Christopher; Davies, Christine; Horgan, Ron; Lepage, G. Peter; Na, Heechang; Shigemitsu, Junko

    2012-01-01

    We calculate the one loop renormalisation parameters for the heavy-light axial-vector and vector currents using lattice perturbation theory. We use NonRelativistic QCD (NRQCD) heavy quarks and the Highly Improved Staggered Quark (HISQ) action for the light quarks. We present results for heavy-light currents with massless HISQ quarks and briefly discuss the extension to heavy-heavy currents with massive HISQ quarks.

  13. Scalar and axial-vector mesons

    CERN Document Server

    Van Beveren, E; Beveren, Eef van; Rupp, George

    2007-01-01

    Nowadays, there exists an abundance of theoretical approaches towards the mesonic spectrum, ranging from confinement models of all kinds, i.e., glueballs, and quark-antiquark, multiquark and hybrid configurations, to models in which only mesonic degrees of freedom are taken into account. Nature seems to come out somewhere in the middle, neither preferring pure bound states, nor effective meson-meson physics with only coupling constants and possibly form factors. As a matter of fact, apart from a few exceptions, like pions and kaons, Nature does not allow us to study mesonic bound states of any kind, which is equivalent to saying that such states do not really exist. Hence, instead of extrapolating from pions and kaons to the remainder of the meson family, it is more democratic to consider pions and kaons mesonic resonances that happen to come out below the lowest threshold for strong decay. Nevertheless, confinement is an important ingredient for understanding the many regularities observed in mesonic spectra...

  14. Chiral power counting of one- and two-body currents in direct detection of dark matter

    International Nuclear Information System (INIS)

    We present a common chiral power-counting scheme for vector, axial-vector, scalar, and pseudoscalar WIMP–nucleon interactions, and derive all one- and two-body currents up to third order in the chiral expansion. Matching our amplitudes to non-relativistic effective field theory, we find that chiral symmetry predicts a hierarchy amongst the non-relativistic operators. Moreover, we identify interaction channels where two-body currents that previously have not been accounted for become relevant

  15. Charm current-current correlators in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    The charm quark mass and the strong coupling constant are two of the fundamental parameters of the Standard Model and the precision of their determination has been continuously enhanced by higher order perturbative QCD calculations combined with more precise experimental data from e+-e-scattering as well as non-perturbative lattice calculations. As opposed to using experimental data to include non-perturbative effects, lattice QCD is not confined to the vector current correlator alone but additionally allows for an extension to the axial vector, scalar and pseudoscalar current correlators giving rise to a larger number of operators to extract the desired parameters from. We study the moments of the diverse charm current-current correlators in the framework of twisted mass lattice QCD with two light dynamical quarks. By matching lattice QCD results to continuum perturbation theory the strong coupling constant and the charm quark mass are extracted and compared to QCD sum rule and previous lattice calculations.

  16. Neutron beta decay and the right-handed current problem

    Energy Technology Data Exchange (ETDEWEB)

    Gaponov, Yu.V.; Shul' gina, N.B.; Spivak, P.E. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow (USSR). Inst. Atomnoj Ehnergii)

    1991-01-10

    The renormalization of the axial-vector coupling constant, {lambda}=g{sub A}/g{sub V}, extracted from the neutron lifeime ({lambda}{sub tau}) and from the neutron beta decay asymmetry ({lambda}{sub c}) is considered carefully in the standard model of the electroweak interaction {lambda}{sub tau} should be equal to {lambda}{sub c}. According to recent experimental data on neutron beta decay, {lambda}{sub tau} and {lambda}{sub c} seem to differ from each other. This fact is explained in the framework of the manifestly left-right symmetric model SU(2){sub L}xSU(2){sub R}xU(1). The possibility of the existence of the right-handed current in the neutron beta decay is pointed out. A joint analysis of neutron beta decay and muon decay is performed, the right-handed current parameters are estimated. The axial-vector constant renormalization ({lambda}{sub N}) by right-handed currents is evaluated. (orig.)D.

  17. Aspects of QCD Current Algebra on a Null Plane

    CERN Document Server

    Beane, Silas R

    2015-01-01

    Consequences of QCD current algebra formulated on a light-like hyperplane are derived for the forward scattering of vector and axial-vector currents on an arbitrary hadronic target. It is shown that current algebra gives rise to a special class of sum rules that are direct consequences of the independent chiral symmetry that exists at every point on the two-dimensional transverse plane orthogonal to the lightlike direction. These sum rules are obtained by exploiting the closed, infinite-dimensional algebra satisfied by the transverse moments of null-plane axial-vector and vector charge distributions. In the special case of a nucleon target, this procedure leads to the Adler-Weisberger, Gerasimov-Drell-Hearn, Cabbibo-Radicatti and Fubini-Furlan-Rossetti sum rules. Matching to the dispersion-theoretic language which is usually invoked in deriving these sum rules, the moment sum rules are shown to be equivalent to algebraic constraints on forward S-matrix elements in the Regge limit.

  18. Aspects of QCD current algebra on a null plane

    Science.gov (United States)

    Beane, S. R.; Hobbs, T. J.

    2016-09-01

    Consequences of QCD current algebra formulated on a light-like hyperplane are derived for the forward scattering of vector and axial-vector currents on an arbitrary hadronic target. It is shown that current algebra gives rise to a special class of sum rules that are direct consequences of the independent chiral symmetry that exists at every point on the two-dimensional transverse plane orthogonal to the lightlike direction. These sum rules are obtained by exploiting the closed, infinite-dimensional algebra satisfied by the transverse moments of null-plane axial-vector and vector charge distributions. In the special case of a nucleon target, this procedure leads to the Adler-Weisberger, Gerasimov-Drell-Hearn, Cabibbo-Radicati and Fubini-Furlan-Rossetti sum rules. Matching to the dispersion-theoretic language which is usually invoked in deriving these sum rules, the moment sum rules are shown to be equivalent to algebraic constraints on forward S-matrix elements in the Regge limit.

  19. Wess-Zumino current and the structure of the decay tau- -->K- pi- K+ nu tau.

    Science.gov (United States)

    Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Haynes, J; Menaa, N; Mountain, R; Muramatsu, H; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, Kevin; Mahmood, A H; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Weinstein, A J; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Patterson, J R; Pedlar, T K; Peterson, D; Pivarski, J; Riley, D; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Sun, W M; Thayer, J G; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stoeck, H; Yelton, J; Eisenstein, B I; Gollin, G D; Karliner, I; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Besson, D; Gao, K Y; Gong, D T; Kubota, Y; Li, S Z; Poling, R; Scott, A W; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Arms, K; Eckhart, E; Gan, K K; Gwon, C; Severini, H; Skubic, P; Asner, D M; Dytman, S A; Mehrabyan, S; Mueller, J A; Nam, S; Savinov, V; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cummings, J P; Danko, I; Napolitano, J; Cronin-Hennessy, D; Park, C S; Park, W; Thayer, J B; Thorndike, E H

    2004-06-11

    We present the first study of the vector (Wess-Zumino) current in tau(-)-->K-pi-K+nu(tau) decay using data collected with the CLEO III detector at the Cornell Electron Storage Ring. We determine the quantitative contributions to the decay width from the vector and axial vector currents. Within the framework of a model by Kühn and Mirkes, we identify the quantitative contributions to the total decay rate from the intermediate states omegapi, rho(')pi, and K*K. PMID:15245150

  20. Renormalization of the weak hadronic current in the nuclear medium

    CERN Document Server

    Siiskonen, T; Suhonen, J

    2001-01-01

    The renormalization of the weak charge-changing hadronic current as a function of the reaction energy release is studied at the nucleonic level. We have calculated the average quenching factors for each type of current (vector, axial vector and induced pseudoscalar). The obtained quenching in the axial vector part is, at zero momentum transfer, 19% for the sd shell and 23% in the fp shell. We have extended the calculations also to heavier systems such as $^{56}$Ni and $^{100}$Sn, where we obtain stronger quenchings, 44% and 59%, respectively. Gamow--Teller type transitions are discussed, along with the higher order matrix elements. The quenching factors are constant up to roughly 60 MeV momentum transfer. Therefore the use of energy-independent quenching factors in beta decay is justified. We also found that going beyond the zeroth and first order operators (in inverse nucleon mass) does not give any substantial contribution. The extracted renormalization to the ratio $C_P/C_A$ at q=100 MeV is -3.5%, -7.1$%, ...

  1. Neutron β decay and right-handed currents

    International Nuclear Information System (INIS)

    The renormalization constant of the axial-vector current, λ = gA/gV, extracted from the neutron lifetime, λt, and from the electron-spin correlation, λc, is considered. In the standard model of the electroweak interactions λT must be equal to λc. According to recent experimental data on neutron β decay, λt and λc seem to differ from each other. This fact is explained in the framework of the manifestly left-right symmetric SU(2)L x SU(2)R x U(1) model. The possible existence of right-handed currents in neutron β decay is pointed out. A joint analysis of neutron β decay and muon decay is performed, and the parameters of the right-handed currents are estimated

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

    International Nuclear Information System (INIS)

    We perform a non-perturbative determination of the improvement coefficient cA 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 cA is imposed at constant physics. Combining our results with the perturbative expansion, cA is now known rather precisely for a-1>or similar 1.6 GeV. (orig.)

  3. Neutron β-decay and right-handed current problem

    International Nuclear Information System (INIS)

    The renormalization of the axial-vector coupling constant, λ=gA/gV, extracted from the neutron lifetime λτ and from the neutron β-decay asymmetry, λc, is considered carefully. In the Standard Model of the electroweak interactions λτ must be equal to λc. According to the recent experimental data on the neutron β decay, λτ and λc seem to differ from each other. This fact is explained in the framework of the manifestly left-right symmetric model SU(2)LxSU(2)RxU(1). The possibility of the existence of the right-handed current in the neutron β decay is pointed out. The joint analysis of the neutron β decay and muon decay is performed and the right-handed current parameters are estimated

  4. Nonperturbative tests of the renormalization of mixed clover-staggered currents in lattice QCD

    CERN Document Server

    Chakraborty, Bipasha; Donald, Gordon; Dowdall, Rachel; Koponen, Jonna; Lepage, G Peter

    2014-01-01

    The Fermilab Lattice and MILC collaborations have shown in one-loop lattice QCD perturbation theory that the renormalization constants of vector and axial-vector mixed clover-asqtad currents are closely related to the product of those for clover-clover and asqtad-asqtad (local) vector currents. To be useful for future higher precision calculations this relationship must be valid beyond one-loop and very general. We test its validity nonperturbatively using clover and Highly Improved Staggered (HISQ) strange quarks, utilising the absolute normalization of the HISQ temporal axial current. We find that the renormalization of the mixed current differs from the square root of the product of the pure HISQ and pure clover currents by $2-3\\%$. We also compare discretization errors between the clover and HISQ formalisms.

  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. Nonperturbative calculation of ZA/ZV for heavy-light currents using Ward-Takahashi identity

    International Nuclear Information System (INIS)

    We determine the ratio of renormalization factors of vector and axial-vector heavy-light currents. The calculation is performed nonperturbatively using the axial Ward-Takahashi identity for the heavy-light currents. We find that the effect of the O(a)-improvement of the heavy-light current is sizable in the strong coupling region g20 > 0.9. Since the nonperturbative determination of its coefficient is not yet available, it leads to an error of order 10% in the nonperturbative determination of the ratio ZhlA/ZhlV. Our result for ZhlA/ZhlV is smaller than the one-loop evaluation, but the difference is within expected two-loop uncertainty

  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)

    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. B→A transitions in the light-cone QCD sum rules with the chiral current

    Institute of Scientific and Technical Information of China (English)

    SUN Yan-Jun; WANG Zhi-Gang; HUANG Tao

    2012-01-01

    In this article,we calculate the form-factors of the transitions B → a1(1260),b1(1235) in the leading-order approximation using the light-cone QCD sum rules.In calculations,we choose the chiral current to interpolate the B-meson,which has the outstanding advantage that the twist-3 light-cone distribution amplitudes of the axial-vector mesons make no contributions,and the resulting sum rules for the form-factors suffer from far fewer uncertainties.Then we study the semi-leptonic decays B → a1(1260)l(v1),b1(1235)l(v1) (l =e,μ,Τ),and make predictions for the differential decay widths and decay widths,which can be compared with the experimental data in the coming future.

  10. Nonperturbative renormalization of the axial current in Nf=3 lattice QCD with Wilson fermions and a tree-level improved gauge action

    Science.gov (United States)

    Bulava, John; Della Morte, Michele; Heitger, Jochen; Wittemeier, Christian

    2016-06-01

    We nonperturbatively determine the renormalization factor of the axial vector current in lattice QCD with Nf=3 flavors of Wilson-clover fermions and the tree-level Symanzik-improved gauge action. The (by now standard) renormalization condition is derived from the massive axial Ward identity, and it is imposed among Schrödinger functional states with large overlap on the lowest lying hadronic state in the pseudoscalar channel, in order to reduce kinematically enhanced cutoff effects. We explore a range of couplings relevant for simulations at lattice spacings of ≈0.09 fm and below. An interpolation formula for ZA(g02) , smoothly connecting the nonperturbative values to the 1-loop expression, is provided together with our final results.

  11. Non-perturbative renormalization of the axial current in $N_f = 3$ lattice QCD with Wilson fermions and tree-level improved gauge action

    CERN Document Server

    Bulava, John; Heitger, Jochen; Wittemeier, Christian

    2016-01-01

    We non-perturbatively determine the renormalization factor of the axial vector current in lattice QCD with $N_f=3$ flavors of Wilson-clover fermions and the tree-level Symanzik-improved gauge action. The (by now standard) renormalization condition is derived from the massive axial Ward identity and it is imposed among Schr\\"{o}dinger functional states with large overlap on the lowest lying hadronic state in the pseudoscalar channel, in order to reduce kinematically enhanced cutoff effects. We explore a range of couplings relevant for simulations at lattice spacings of $\\approx 0.09$ fm and below. An interpolation formula for $Z_A(g_0^2)$, smoothly connecting the non-perturbative values to the 1-loop expression, is provided together with our final results.

  12. Axial-vector dominance predictions in quasielastic neutrino-nucleus scattering

    CERN Document Server

    Amaro, J E

    2015-01-01

    We use the minimum meson-dominance ansatz compatible with low- and high energy constrains to model the nucleon axial form factor. The parameters of the resulting axial form factor are the masses and widths of the two axial mesons, incorporated as a product of monopoles. By applying the half width rule in a Monte Carlo simulation a distribution of theoretical predictions can be generated for the neutrino-nucleus quasielastic cross section. We test the model by applying it to the $(\

  13. Observation of a New Narrow Axial-Vector Meson a1(1420).

    Science.gov (United States)

    Adolph, C; Akhunzyanov, R; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anosov, V; Austregesilo, A; Azevedo, C; Badełek, 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; Büchele, 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; Dünnweber, W; Duic, V; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger, M; Fischer, H; Franco, C; du 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-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; Jörg, 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; 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 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; Schmeing, S; Schmidt, K; Schmieden, H; Schönning, K; Schopferer, S; Schlüter, 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; 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

    2015-08-21

    The COMPASS Collaboration at CERN has measured diffractive dissociation of 190  GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15))  MeV/c2 and width (153(-23)(+8))  MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature. PMID:26340182

  14. 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.; M. Finger 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.

    2015-01-01

    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.

  15. 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...

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

    CERN Document Server

    Franzosi, Diogo Buarque; Cai, Haiying; Deandrea, Aldo; Frandsen, Mads

    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 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.

  17. Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State

    OpenAIRE

    Pham, T. N.

    2013-01-01

    The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. There...

  18. a Measurement of the Asymmetry Parameter for Argon -35 Beta-Decay as a Test of the Conserved Vector Current Hypothesis

    Science.gov (United States)

    Converse, Alexander Milovan

    The spatial asymmetry of positrons emitted parallel and antiparallel to the spin axis of a polarized sample of ^{35}Ar has been measured. The measured asymmetry parameter for the mixed Fermi--Gamow - Teller decay ^{35}Ar( beta^+)^{35}Cl is A_0 = 0.427(23). This agrees with the value predicted by the Standard Model, A _0^{rm theory} = 0.4302(86). The Standard Model prediction assumes vector-axial vector couplings and the validity of the conserved vector current hypothesis; the vector coupling strength is derived from comparative half-lives of pure Fermi 0^+to0^+ transitions, and the ratio of axial vector to vector coupling strengths is calculated using the ^ {35}Ar comparative half-life. In the measurement, polarized ^{35}Ar was created by bombarding a Cl_2 target with 68% polarized 9.2 MeV protons. Positrons emitted at 0^circ and 180 ^circ with respect to the ^{35}Ar polarization axis were observed with DeltaE-E plastic scintillator detectors. The ^{35}Ar polarization was determined from the asymmetry of positrons emitted in the decays ^{35}Ar( beta^+)^{35}Cl ^*, which were identified by the observation of coincident gamma - rays in pure Ge detectors. The decay to the first excited state of ^{35}Cl is pure Gamow - Teller, so its asymmetry parameter may be derived from angular momentum coupling arguments without reference to the Standard Model. The relative uncertainty in this measurement, DeltaA_0 /A_0 = 5.4%, is the quadratic sum of the statistical error, 5.4%, and systematic errors, 0.5%. In light of published measurements of the neutron asymmetry parameter, which are accurate to 1.5% and disagree with the Standard Model prediction by more than 2 sigma, it might be worthwhile to repeat the measurement of the ^{35}Ar ground state asymmetry parameter to obtain statistical precision of <2%.

  19. Measurement of the Neutrino Neutral-Current Elastic Differential Cross Section on Mineral Oil at Ev ∼ 1 GeV

    International Nuclear Information System (INIS)

    We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH2) as a function of four-momentum transferred squared, Q2. It is obtained by measuring the kinematics of recoiling nucleons with kinetic energy greater than 50 MeV which are readily detected in MiniBooNE. This differential cross-section distribution is fit with fixed nucleon form factors apart from an axial mass, MA, that provides a best fit for MA = 1.39 ± 0.11 GeV. Using the data from the charged-current neutrino interaction sample, a ratio of neutral-current to charged-current quasi-elastic cross sections as a function of Q2 has been measured. Additionally, single protons with kinetic energies above 350 MeV can be distinguished from neutrons and multiple nucleon events. Using this marker, the strange quark contribution to the neutral-current axial vector form factor at Q2 = 0, Δs, is found to be Δs = 0.08± 0.26.

  20. Detection of the weak neutral current using fission anti ν/sub e/ on deuterons with concurrent measurement of the charged current branch

    International Nuclear Information System (INIS)

    The target consists of 268 kg of extremely pure (99.85%) heavy water (D2O), contained in a cylindrical stainless steel tank 122 cm in height and 54 cm in diameter. This target is surrounded by a lead and cadmium shield and immersed in a 2200 liter liquid scintillator anticoincidence detector. This system is a well-shielded environment. The center of the detector is located 11 meters from the center of the reactor core in an electron antineutrino flux of 2.5 x 1013 anti ν/sub e//cm2-s. Immersed in the target are ten 5.08-cm-diameter 3He-filled gas proportional counters, which detect the neutron via the reaction 3He + n → p + 3H + 773 keV. The system has been determined to have an overall neutron detection efficiency of 0.32 +- 0.02. The data are taken with a combination of scalers, a pulse height analyzer, and oscilloscope traces. Single, double, and triple neutron capture events are recorded with the reactor on and off. Data have been accumulated for 104 live days reactor on, and 72 live days reactor off for the charged-current reaction and 52 live days reactor on and 34 live days reactor off for the neutral-current reaction. The measured neutral-current cross section is (5.0 +- 0.8) x 10-45cm2/anti ν/sub e/, consistent with the Weinberg-Salam model. The charged-current reaction cross section is (1.5 +- 0.4) x 10-45 cm2/ν/sub e/, in fair agreement with expectation. From the N.C. cross section a value of the square of the isovector axial-vector coupling constant is deduced to be β2 = 1.0 +- 0.15

  1. Pionic decays and saturation of current-algebra sum rules in a nonrelativistic expansion of the quark shell model

    International Nuclear Information System (INIS)

    Pionic decays of hadrons are calculated using a PCAC (partial conservation of axial-vector current) prescription and a quark shell model with quarks bound by a central potential, described by the Dirac equation. The Dirac Hamiltonian and operators are expanded in v/c, the internal quark velocity. Then, one finds an exact saturation of the current-algebra sum rules as defined in the SU(2)xSU(2) symmetry of Gilman-Harari and Weinberg up to order v4/c4. The saturation is obtained without need of exotics, with the usual excitations of the ground state. The relation with the P = infinity approach is clarified. The corrections found with respect to previous quark models in L = 2 decays are discussed. They do not solve the problem of SU(6)/sub W/ coupling signs. Finally, the whole Weinberg scheme of linear SU(2)xSU(2) symmetry is completed by the expression of the chiral-breaking part of the mass operator m4/sup ts2/

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

    International Nuclear Information System (INIS)

    The coherent production of π and ρ mesons in νμ(bar νμ)--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 (bar νμ) 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±πminus-plus coherent events and (19±7) μ±πminus-plusπ0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2±0.7)x10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1±0.8)x10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at |t|2 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

  3. 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.

  4. Current stabilizer

    International Nuclear Information System (INIS)

    A current stabilizer for supplying magnetic lens of β-monochromator at the electron energy up to 1 MeV is described. Stabilization method with use of reference high-stabilized source of direct voltage with switching-in loading (monochromator coil) to circuit of negative feedback of direct-current amplifier with high gain is chosen for stabilization of direct current. The range of current regulation is 0.5 A at available power up to 15 W. Current instability during 10 hour continuous work does not exceed 10-4% that makes it possible to provide instability of electron energy at the monochromator exit using 90Sr+90Y β-nucleide of not more than 10 -4% and number of electrons 2.5x10-4% respectively

  5. G-parity violation of weak nucleon current and in-medium mass renormalization of nucleons detected through the β decays of spin aligned 12B and 12N

    International Nuclear Information System (INIS)

    The β-ray angular distributions from purely spin aligned 12B and 12N 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 fT/fA ≤ 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 %

  6. Neutral currents

    International Nuclear Information System (INIS)

    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

  7. 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.

  8. Neutral Current $\

    CERN Document Server

    Chauhan, S; Singh, S K

    2011-01-01

    We calculate cross sections for the neutral current induced neutrino/antineutrino reaction from $^{208}Pb$ target and applied it to study Supernova neutrino event rates. The calculations are done in local density approximation taking into account Pauli blocking, Fermi motion effects and renormalization of weak transition strengths in the nuclear medium. The numerical results for the neutrino nucleus total cross sections have been averaged over the various Supernova neutrino/antineutrino fluxes available in literature.

  9. 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.

  10. 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...

  11. Neutral currents

    International Nuclear Information System (INIS)

    A short survey of the new experimental data on weak neutral currents is given, followed by a comparison with modern theoretical models. Cross sections of the anti νsub(e)e → anti νsub(e)e, anti νsub(μ)e→ νsub(μ)e, νp → νp and anti νp → anti νp elastic scattering as well as inclusive cross sections of the ν+N → ν+X and anti ν+N → anti ν+X deep inelastic scattering are presented. On the basis of the comparison the Weinberg-Salam model is concluded to be in a good agreement with the shape of the cross sections. Six-quark vector models appear to be ruled out. The five-quark model due to Achiman, Koller and Walsh and two versions of the Gursey-Sikivie model satisfactorily account for the observed data in shape and in magnitude

  12. The current catalog--how current?

    Science.gov (United States)

    Sargent, C W

    1968-07-01

    NLM's Current Catalog has recently come in for some criticism. To be useful as a tool in acquisition and cataloging, currency in receipt of the Current Catalog is necessary. A survey of 263 titles with 1967 imprints, which were received by the Library of the Medical Sciences, University of New Mexico School of Medicine, was made to determine the correlation between the receipt of these books in the library and their appearance in the Current Catalog. PMID:5695111

  13. Current lead thermal analysis code 'CURRENT'

    International Nuclear Information System (INIS)

    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)

  14. Current measurement apparatus

    Science.gov (United States)

    Umans, Stephen D.

    2008-11-11

    Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

  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 U.

    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 {nu}{sub {mu}} {yields} {nu}{sub x} oscillation measurements. There are two contributions to this process: single pion production via baryonic resonance ({nu}{sub {mu}}N {yields} {mu}{sup -} N{pi}{sup +}) and coherent pion production interacting with the entire nucleus ({nu}{sub {mu}}A {yields} {mu}{sup -} A{pi}{sup +}), 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, {nu}{sub {mu}} {sup 12}C {yields} {mu}{sup -12}C{pi}{sup +}, 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 10{sup 20} 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 10{sup 20} protons on target. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio of charged

  16. 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

  17. 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,

  18. Marine Current Energy Conversion

    OpenAIRE

    Lundin, Staffan

    2016-01-01

    Marine currents, i.e. water currents in oceans and rivers, constitute a large renewable energy resource. This thesis presents research done on the subject of marine current energy conversion in a broad sense. A review of the tidal energy resource in Norway is presented, with the conclusion that tidal currents ought to be an interesting option for Norway in terms of renewable energy. The design of marine current energy conversion devices is studied. It is argued that turbine and generator cann...

  19. Current Research Studies

    Science.gov (United States)

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

  20. Eddy current seminar

    International Nuclear Information System (INIS)

    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.)

  1. Current enhancement update

    International Nuclear Information System (INIS)

    Net current enhancement to levels in excess of the beam current has been observed in gases at pressures excess of 50 torr. We delineate the regimes where enhancement is observed. The experimental results fall into two very distinct classes; current enhancement at injection where the beam is only slightly displaced and current enhancement clearly associated with the high amplitude hose instability. A careful theoretical and experimental study of the diagnostics revealed no fundamental flaws although there are several complex and unlikely scenarios which could introduce fictitious current enhancement. Theoretical efforts indicate several mechanisms for generating enhancement but none of the theories can account for the detailed observations. 4 references, 4 figures

  2. Fast wave current drive

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Measurement of Neutrino-Nucleon Neutral-Current Elastic Scattering Cross-section at SciBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Takei, Hideyuki; /Tokyo Inst. Tech.

    2009-02-01

    In this thesis, results of neutrino-nucleon neutral current (NC) elastic scattering analysis are presented. Neutrinos interact with other particles only with weak force. Measurement of cross-section for neutrino-nucleon reactions at various neutrino energy are important for the study of nucleon structure. It also provides data to be used for beam flux monitor in neutrino oscillation experiments. The cross-section for neutrino-nucleon NC elastic scattering contains the axial vector form factor G{sub A}(Q{sup 2}) as well as electromagnetic form factors unlike electromagnetic interaction. G{sub A} is propotional to strange part of nucleon spin ({Delta}s) in Q{sup 2} {yields} 0 limit. Measurement of NC elastic cross-section with smaller Q{sup 2} enables us to access {Delta}s. NC elastic cross-sections of neutrino-nucleon and antineutrino-nucleon were measured earlier by E734 experiment at Brookheaven National Laboratory (BNL) in 1987. In this experiment, cross-sections were measured in Q{sup 2} > 0.4 GeV{sup 2} region. Result from this experiment was the only published data for NC elastic scattering cross-section published before our experiment. SciBooNE is an experiment for the measurement of neutrino-nucleon scattering cross-secitons using Booster Neutrino Beam (BNB) at FNAL. BNB has energy peak at 0.7 GeV. In this energy region, NC elastic scattering, charged current elastic scattering, charged current pion production, and neutral current pion production are the major reaction branches. SciBar, electromagnetic calorimeter, and Muon Range Detector are the detectors for SciBooNE. The SciBar consists of finely segmented scintillators and 14336 channels of PMTs. It has a capability to reconstruct particle track longer than 8 cm and separate proton from muons and pions using energy deposit information. Signal of NC elastic scattering is a single proton track. In {nu}p {yields} {nu}p process, the recoil proton is detected. On the other hand, most of {nu}n {yields} {nu

  4. Shaft Current Protection

    OpenAIRE

    Rabuzin, Tin

    2015-01-01

    Shaft current protection in hydro and turbo generators is an important generatorprotection issue. Currents owing in the generator shaft might damagegenerator bearings which, in turn, could reduce operating time and cause largenancial losses. Therefore, it is important to prevent operation of the generatorunder conditions of high shaft currents.In this project, task was to develop measurement and protection system thatis able to operate under certain conditions. Measurement device has to be ab...

  5. The weak currents

    International Nuclear Information System (INIS)

    The main facts known on the structure of the weak hadronic current are given. An attempt is made to elucidate the physical meaning of different hypotheses such as C.V.C., PCAC, SU(3) and angle theta, chiral algebra, which have led to progress in the understanding of weak interactions. The central problem to overcome in order to specify the structure of the hadronic current is the fact that gaps remain in the knowledge of strong interactions. However a solution has been found by assuming that the weak current is a combination of the currents associated with exact or approximate symmetries of strong interactions

  6. 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.

  7. Superconducting current generators

    International Nuclear Information System (INIS)

    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)

  8. Current and Current Fluctuations in Quantum Shuttles

    DEFF Research Database (Denmark)

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

    2005-01-01

    We review the properties of electron shuttles, i.e., nanoelectromechanical devices that transport electrons one by one by utilizing a combination of electronic and mechanical degrees of freedom. We focus on the extreme quantum limit, where the mechanical motion is quantized. We introduce the main...... 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...

  9. IMEF eddy current test

    International Nuclear Information System (INIS)

    The eddy current inspection technique which can detects in irradiated fuel rod cladding is described. Theoretical considerations for eddy current experiments devices, and experimental procedures are described. By doing the experiments on standard sample, conditions for defect test are established. (author). 1 tab., 9 figs., 5 refs

  10. Direct current transformer

    Science.gov (United States)

    Khanna, S. M.; Urban, E. W. (Inventor)

    1979-01-01

    A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

  11. Charged weak currents

    International Nuclear Information System (INIS)

    In this review of charged weak currents we shall concentrate on inclusive high energy neutrino physics. The plan of this review is the following: general structure of charged current; new results on total cross-section; Callan-Gross relation; antiquark distribution; scaling violations and tests of QCD. At the end we will give a very short summary on multilepton physics

  12. Voltage controlled current source

    International Nuclear Information System (INIS)

    A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode. 6 figs

  13. 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...

  14. NOAA NDBC SOS - currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. Because of the nature of SOS requests, requests for...

  15. 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...

  16. 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)

  17. Rigid current Lie algebras

    OpenAIRE

    Goze, Michel; Remm, Elisabeth

    2006-01-01

    A current Lie algebra is contructed from a tensor product of a Lie algebra and a commutative associative algebra of dimension greater than 2. In this work we are interested in deformations of such algebras and in the problem of rigidity. In particular we prove that a current Lie algebra is rigid if it is isomorphic to a direct product gxg...xg where g is a rigid Lie algebra.

  18. 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.

  19. Strange Quark Contributions to Parity-Violating Asymmetries in the Backward Angle G0 Electron Scattering Experiment

    International Nuclear Information System (INIS)

    We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2=0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of < or approx. 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial-vector current at these four-momentum transfers.

  20. Eddy current damper

    Science.gov (United States)

    Ellis, R. C.; Fink, R. A.; Rich, R. W.

    1989-01-01

    A high torque capacity eddy current damper used as a rate limiting device for a large solar array deployment mechanism is discussed. The eddy current damper eliminates the problems associated with the outgassing or leaking of damping fluids. It also provides performance advantages such as damping torque rates, which are truly linear with respect to input speed, continuous 360 degree operation in both directions of rotation, wide operating temperature range, and the capability of convenient adjustment of damping rates by the user without disassembly or special tools.

  1. Regularization of current algebra

    CERN Document Server

    Mickelsson, J

    1993-01-01

    In this talk I want to explain the operator substractions needed to regularize gauge currents in a second quantized theory. The case of space-time dimension $3+1$ is considered in detail. In presence of chiral fermions the regularization effects a modification of the local commutation relations of the currents by local Schwinger terms. In $1+1$ dimensions one gets the usual central extension (Schwinger term does not depend on background gauge field) whereas in $3+1$ dimensions one gets an anomaly linear in the background potential.

  2. Feedback cooling of currents

    Science.gov (United States)

    Washburn, Sean

    1989-02-01

    Just as feedback can be used to correct errors in the output voltages of amplifiers, it can also be used to remove noise from the current through a resistor. Such a feedback amplifier behaves as a refrigerator cooling the electrons in a resistor connnected to it. This principle has been recognized since the 1940s but has been largely ignored because the cooling power available from such refrigerators is miniscule. It is pointed out here that the method might be practical for cooling the currents in the microscopic circuits that are typical of modern electrical engineering and recent studies in transport physics.

  3. The Anderson Current Loop

    Science.gov (United States)

    Anderson, Karl F.

    1994-01-01

    Four-wire-probe concept applied to electrical-resistance transducers. Anderson current loop is excitation-and-signal-conditioning circuit suitable for use with strain gauges, resistance thermometers, and other electrical-resistance transducers mounted in harsh environments. Used as alternative to Wheatstone bridge. Simplifies signal-conditioning problem, enabling precise measurement of small changes in resistance of transducer. Eliminates some uncertainties in Wheatstone-bridge resistance-change measurements in flight research. Current loop configuration makes effects of lead-wire and contact resistances insignificantly small. Also provides output voltage that varies linearly with change in gauge resistance, and does so at double sensitivity of Wheatstone bridge.

  4. Weak quark couplings induced by gluon corrections

    International Nuclear Information System (INIS)

    We compute the quark couplings in flavor-changing semileptonic transitions induced by lowest-order gluon corrections. We investigate the consequences of these radiative corrections for the quark axial-vector coupling, the deviations from Cabibbo universality for the axial-vector relative to the vector current, and the induced couplings (first-class pseudoscalar and anomalous magnetic moment, and second-class scalar and pseudotensor). The correction lowers the axial-vector coupling and increases the magnetic moment. We study the dependence of the couplings on the quark mass difference. Some of these results, true to all orders in α/sub s/, generalize the theorem of Ademollo and Gatto. The effective current is pure V-A to a very good approximation for transitions of heavy quarks

  5. Experimental limits on the strength of weak neutral currents in lepton pair production at PETRA energies

    International Nuclear Information System (INIS)

    The processes e+ esup(a)nd → e+ e- and μ+ μ- have been studied at PETRA using the JADE detector. The data, which were collected at s values of up to 1300 GeV2 have been analysed in terms of an electro-weak extension of QED to obtain values for the weak vector and axial vector couplings in the lepton sector. The values obtained agree with the predictions of the standard Salam-Weinberg model and the data are further analysed in terms of this model to obtain the limits 0.10 2THETAsub(w) 0.40 (68% C.L.). The mass of the neutral weak gauge boson is deduced to be greater than 51 GeVc2. (orig.)

  6. Current topics in photovoltaics

    International Nuclear Information System (INIS)

    This book contains papers on current research in photovoltaics. Areas include: outdoor spectral odor radiation variations and their relationship to photovoltaic device performance, numerical modeling for analysis and design of solar cells, radiation damage mechanisms in GaAs and Si solar cells, and health and safety issues in the manufacturing of photovoltaic cells

  7. Second class weak currents

    International Nuclear Information System (INIS)

    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

  8. Issues in neutral currents

    International Nuclear Information System (INIS)

    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.)

  9. Current management of presbyopia

    Directory of Open Access Journals (Sweden)

    Pandelis A Papadopoulos

    2014-01-01

    Full Text Available Presbyopia is a physiologic inevitability that causes gradual loss of accommodation during the fifth decade of life. The correction of presbyopia and the restoration of accommodation are considered the final frontier of refractive surgery. Different approaches on the cornea, the crystalline lens and the sclera are being pursued to achieve surgical correction of this disability. There are however, a number of limitations and considerations that have prevented widespread acceptance of surgical correction for presbyopia. The quality of vision, optical and visual distortions, regression of effect, complications such as corneal ectasia and haze, anisometropia after monovision correction, impaired distance vision and the invasive nature of the currently techniques have limited the utilization of presbyopia surgery. The purpose of this paper is to provide an update of current procedures available for presbyopia correction and their limitations.

  10. The NLM current catalog.

    Science.gov (United States)

    Wiggins, E V

    1969-01-01

    When the National Library of Medicine acquired a computer to augment its publication program, the intent was to present in one medium an index to journal articles and a catalog of books and new serial titles. The computer programs designed for indexing were unsatisfactory for cataloging, however; so two publications were issued, the Index Medicus and the NLM Current Catalog. The Current Catalog features separate name and subject sections, added volumes, and technical reports. The Express Cataloging Service was one of the first attempts to increase the speed and coverage of the Catalog. Shared cataloging with the Library of Congress, the Countway Library at Harvard, and the Upstate Medical Library in Syracuse, New York, have also contributed to the efforts toward improving this library service. An additional shared cataloging program, this time with the National Medical Audiovisual Center, is expected to be implemented shortly. PMID:5782262

  11. Light Cone Current Algebra

    OpenAIRE

    Fritzsch, H.; Gell-Mann, M.

    2003-01-01

    This talk follows by a few months a talk by the same authors on nearly the same subject at the Coral Gables Conference. The ideas presented here are basically the same, but with some amplification, some change of viewpoint, and a number of new questions for the future. For our own convenience, we have transcribed the Coral Gables paper, but with an added ninth section, entitled "Problems of light cone current algebra", dealing with our present views and emphasizing research topics that requir...

  12. Current ADC Linker Chemistry

    OpenAIRE

    Jain, Nareshkumar; Smith, Sean W.; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-01-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugati...

  13. Sustainable winegrowing: current perspectives

    OpenAIRE

    Mariani A; Vastola A

    2015-01-01

    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 consensu...

  14. Lupus nephritis: current update

    OpenAIRE

    Saxena, Ramesh; Mahajan, Tina; Mohan, Chandra

    2011-01-01

    Lupus nephritis is a major cause of morbidity and mortality in patients with systemic lupus erythematosus. The general consensus is that 60% of lupus patients will develop clinically relevant nephritis at some time in the course of their illness. Prompt recognition and treatment of renal disease is important, as early response to therapy is correlated with better outcome. The present review summarizes our current understanding of the pathogenic mechanisms underlying lupus nephritis and how th...

  15. Charged current review

    International Nuclear Information System (INIS)

    Experimental measurements of the τ lifetime and leptonic branching ratios are combined to give updated world averages for these quantities. The results are then used to test the universality of the electroweak charged current couplings to the three lepton species and are found to be consistent with Standard Model predictions at the level of 0.2%, permitting limits to be derived on non-Standard Model physics such as the mass of the τ neutrino

  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. Molecular current switch

    Czech Academy of Sciences Publication Activity Database

    Nešpůrek, Stanislav; Sworakowski, J.

    Brno : Faculty of Chemistry, Brno University of Technology, 2002 - (Schauer, F.), s. 89-96 ISBN 80-214-2265-3. [Seminar on Physics and Chemistry of Molecular Systems /7./. Brno (CZ), 13.12.2001] R&D Projects: GA AV ČR IAA1050901; GA ČR GA202/01/0518 Institutional research plan: CEZ:AV0Z4050913 Keywords : current switch * local states * dipolar species Subject RIV: BM - Solid Matter Physics ; Magnetism

  18. Fast wave current drive

    International Nuclear Information System (INIS)

    Experiments on the fast wave in the range of high ion cyclotron harmonics in the ACT-1 device show that current drive is possible with the fast wave just as it is for the lower hybrid wave, except that it is suitable for higher plasma densities. A 1400 loop antenna launched the high ion cyclotron harmonic fast wave [ω/Ω = O(10)] into a He+ plasma with n/sub e/approx. =4 x 1012 cm-3 and B = 4.5 kG. Probe and magnetic loop diagnostics and FIR laser scattering confirmed the presence of the fast wave, and the Rogowski loop indicated that the circulating plasma current increased by up to 40A with 1 kW of coupled power, which is comparable to lower hybrid current drive in the same device with the same unidirectional fast electron beam used as the target for the RF. A phased antenna array would be used for FWCD in a tokamak without the E-beam

  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. Turbulent current drive

    International Nuclear Information System (INIS)

    The Ohm's law is modified when turbulent processes are accounted for. Besides an hyper-resistivity, already well known, pinch terms appear in the electron momentum flux. Moreover it appears that turbulence is responsible for a source term in the Ohm's law, called here turbulent current drive. Two terms contribute to this source. The first term is a residual stress in the momentum flux, while the second contribution is an electro-motive force. A non zero average parallel wave number is needed to get a finite source term. Hence a symmetry breaking mechanism must be invoked, as for ion momentum transport. E × B shear flows and turbulence intensity gradients are shown to provide similar contributions. Moreover this source term has to compete with the collision friction term (resistivity). The effect is found to be significant for a large scale turbulence in spite of an unfavorable scaling with the ratio of the electron to ion mass. Turbulent current drive appears to be a weak effect in the plasma core, but could be substantial in the plasma edge where it may produce up to 10 % of the local current density

  1. Renormalization of current algebra

    CERN Document Server

    Mickelsson, J

    1993-01-01

    In this talk I want to explain the operator substractions needed to renormalize gauge currents in a second quantized theory. The case of space-time dimensions $3+1$ is considered in detail. In presence of chiral fermions the renormalization effects a modification of the local commutation relations of the currents by local Schwinger terms. In $1+1$ dimensions on gets the usual central extension (Schwinger term does not depend on background gauge field) whereas in $3+1$ dimensions one gets an anomaly linear in the background potential. We extend our method to the spatial components of currents. Since the bose-fermi interaction hamiltonian is of the form $j^k A_k$ (in the temporal gauge) we get a new renormalization scheme for the interaction. The idea is to define a field dependent conjugation for the fermi hamiltonian in the one-particle space such that after the conjugation the hamiltonian can be quantized just by normal ordering prescription.

  2. 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

  3. 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.

  4. Saturn's Other Ring Current

    Science.gov (United States)

    Crary, F. J.

    2014-04-01

    Saturn's main rings orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the ring particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the rings suggests that its speed would be couppled to the keplarian velocity of the rings themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the ring plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's rings have been reported by O'Donoghue et al., 2013, and interpreted as a result of ring "rain", i.e. precipitating water group species from the rings which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be

  5. Generalized Quantum Current Algebras

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liu

    2001-01-01

    Two general families of new quantum-deformed current algebras are proposed and identified both as infinite Hopf family of algebras, a structure which enables one to define "tensor products" of these algebras. The standard quantum affine algebras turn out to be a very special case of the two algebra families, in which case the infinite Hopf family structure degenerates into a standard Hopf algebra. The relationship between the two algebraic families as well as thefr various special examples are discussed, and the free boson representation is also considered.

  6. Teleradiology - current status

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    F. A. Romaniouk; A. A. Tishechkin; V. I. Roumiantsev; I. V. Novash; N. N. Bobko; E. V. Glinsky

    2010-01-01

    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 analyze...

  8. 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.

  9. Current Controlled Current Differencing Buffered Amplifier: Implementation and Applications

    Directory of Open Access Journals (Sweden)

    Sudhanshu Maheshwari

    2004-01-01

    Full Text Available A new four terminal current-controlled active element is introduced, where parasitic resistances at two current input ports are controlled leading to the definition of current-controlled current differencing buffered amplifier. Bipolar implementation and as application current-mode band-pass filter circuits are proposed. Simulation results using real device parameters are included, which show device bandwidth of 35 MHz, low total harmonic distortions, and tuning over a wide current range.

  10. Current energy situation

    International Nuclear Information System (INIS)

    The current energy situation in Cuba is that of a SIDS in the midst of a recovery from the dissolution of favourable trade agreements with the former Soviet Union for the import of crude oil and petroleum products. As with other SIDS, Cuba lacks sufficient proven indigenous fossil energy resources to support sustainable long term economic and social development. This situation, however, might change as a result of ongoing programmes in oil exploration in the Gulf of Mexico. In addition, the accelerated development of renewable sources is expected to make domestic energy supplies more accessible. Currently, the Cuban energy situation is characterized by a deficit in access to affordable energy services (especially in rural areas), the lack of finance for energy imports and energy infrastructure improvements and expansion as well as suboptimal institutional coordination. This section reviews the status of Cuba's energy system and how it developed. It is divided into four major sections: Section 2.1 outlines the organizational structure of the energy system; Section 2.2 presents the national energy balance; Section 2.3 assesses the country's energy status according to the economic, social, environmental and institutional dimensions of sustainable development; and Section 2.4 summarizes the major issues facing that system

  11. Dispersion and current measurements

    International Nuclear Information System (INIS)

    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)

  12. Current Climate Variability & Change

    Science.gov (United States)

    Diem, J.; Criswell, B.; Elliott, W. C.

    2013-12-01

    Current Climate Variability & Change is the ninth among a suite of ten interconnected, sequential labs that address all 39 climate-literacy concepts in the U.S. Global Change Research Program's Climate Literacy: The Essential Principles of Climate Sciences. The labs are as follows: Solar Radiation & Seasons, Stratospheric Ozone, The Troposphere, The Carbon Cycle, Global Surface Temperature, Glacial-Interglacial Cycles, Temperature Changes over the Past Millennium, Climates & Ecosystems, Current Climate Variability & Change, and Future Climate Change. All are inquiry-based, on-line products designed in a way that enables students to construct their own knowledge of a topic. Questions representative of various levels of Webb's depth of knowledge are embedded in each lab. In addition to the embedded questions, each lab has three or four essential questions related to the driving questions for the lab suite. These essential questions are presented as statements at the beginning of the material to represent the lab objectives, and then are asked at the end as questions to function as a summative assessment. For example, the Current Climate Variability & Change is built around these essential questions: (1) What has happened to the global temperature at the Earth's surface, in the middle troposphere, and in the lower stratosphere over the past several decades?; (2) What is the most likely cause of the changes in global temperature over the past several decades and what evidence is there that this is the cause?; and (3) What have been some of the clearly defined effects of the change in global temperature on the atmosphere and other spheres of the Earth system? An introductory Prezi allows the instructor to assess students' prior knowledge in relation to these questions, while also providing 'hooks' to pique their interest related to the topic. The lab begins by presenting examples of and key differences between climate variability (e.g., Mt. Pinatubo eruption) and

  13. Currently available antitussives.

    Science.gov (United States)

    Dicpinigaitis, Peter V

    2009-04-01

    Cough is among the most common complaints for which patients seek medical attention. Acute cough, usually due to a viral upper respiratory tract infection, generates a huge expenditure on prescription and over-the-counter cough and cold preparations worldwide. Most of these agents, however, have not been shown to be more effective than placebo in adequately performed clinical trials. The goal of management in chronic cough is treatment of its underlying cause. However, certain situations will necessitate cough suppressant therapy for symptomatic relief. Unfortunately, currently available antitussives, such as the opioids, are not consistently effective, or achieve therapeutic effect at the expense of unpleasant or intolerable side effects. Safer and more effective cough suppressants are desperately needed. Potential novel antitussives will need to be evaluated in properly formulated clinical trials, measuring relevant subjective and objective end points in appropriate subject populations. PMID:18771744

  14. Transungual permeation: current insights.

    Science.gov (United States)

    Bhuptani, Ronak S; Deshpande, Ketaki M; Patravale, Vandana B

    2016-08-01

    Nail disorders are beyond cosmetic concern; besides discomfort in the performance of daily chores, they disturb patients psychologically and affect their quality of life. Fungal nail infection (onychomycosis) is the most prevalent nail-related disorder affecting a major population worldwide. Overcoming the impenetrable nail barrier is the toughest challenge for the development of efficacious topical ungual formulation. Sophisticated techniques such as iontophoresis and photodynamic therapy have been proven to improve transungual permeation. This article provides an updated and concise discussion regarding the conventional approach and upcoming novel approaches focused to alter the nail barrier. A comprehensive description regarding preformulation screening techniques for the identification of potential ungual enhancers is also described in this review while highlighting the current pitfalls for the development of ungual delivery. PMID:26419676

  15. Current Management of Pemphigus

    Directory of Open Access Journals (Sweden)

    Soner Uzun

    2012-09-01

    Full Text Available Corticosteroids decreased the mortality rates of pemphigus as dramatically, and they are still the baseline treatment and cornerstone of pemphigus management. Systemic corticosteroids, in combination with adjuvant corticosteroid-sparing immunosuppressive drugs, are the conventional therapy for pemphigus. However, because of both refractory patients and the serious side effects of immunosuppressive drugs, the treatment of pemphigus patients is still challenging. Although they have limited evidence, more recently, monoclonal anti-CD20 antibody, rituximab, high-dose intravenous immunoglobulins and immunoadsorption have been established as additional successful therapeutic options. In this article both conventional therapies and most current treatment strategies for pemphigus are reviewed on the basis of clinical experiences. (Turk J Dermatol 2012; 6: 91-101

  16. Perihilar cholangiocarcinoma: Current therapy

    Institute of Scientific and Technical Information of China (English)

    Wei; Zhang; Lu-Nan; Yan

    2014-01-01

    Perihilar cholangiocarcinoma, which is a rare primary malignancy, originates from the epithelial cells of the bile duct. Usually invading the periductal tissues and the lymph nodes, perihilar cholangiocarcinoma is commonly diagnosed in the advanced stage of the disease and has a dismal prognosis. Currently, complete hepatectomy is the primary therapy for curing this disease. Perioperative assessment and available surgical procedures can be considered for achieving a negative margin resection, which is associated with long-term survival and better quality of life. For patients with unresectable cholangiocarcinoma, several palliative treatments have been demonstrated to produce a better outcome; and liver transplantation for selected patients with perihilar cholangiocarcinoma is promising and desirable. However, the role of palliative treatments and liver transplantation was controversial and requires more evidence and substantial validity from multiple institutions. In this article, we summarize the data from multiple institutions and discuss the resectability, mortality, morbidity and outcome with different approaches.

  17. Eddy current inspection methodology

    International Nuclear Information System (INIS)

    World-wide operating experience with nuclear pressurized water reactors shows that most steam generators show evidence of major degradation phenomena. Laborelec has designed several automated inspection systems using eddy current (bobbin coil, pancake coils and rotating coil) and ultrasound techniques. The bobbin coil is mostly used as a fast and global detection method while dedicated sensors, like the rotating pancake coil, are applied for an improved defect characterization. Experience has demonstrated that significant advantages in accuracy, reliability and cost are intimately related to the automation process. In conclusion: The concept of a multipurpose inspection system satisfies the safety goal and the utility requirements for reliability, accuracy and lower costs. An optimum was reached by equipment modularity, computer control and integrated design of sensors and instrumentation. What previously required several man-weeks of work is now achieved within a few hours time. With a presently unparalleled field performance, Laborelec has set the basis of new industrial standards

  18. 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.

  19. Brain abscess: Current management.

    Science.gov (United States)

    Alvis Miranda, Hernando; Castellar-Leones, Sandra Milena; Elzain, Mohammed Awad; Moscote-Salazar, Luis Rafael

    2013-08-01

    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. PMID:24174804

  20. Osteomyelitis: a current challenge

    Directory of Open Access Journals (Sweden)

    Luciana Souza Jorge

    2010-06-01

    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.

  1. 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

  2. [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. PMID:24018740

  3. 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…

  4. Fahr's disease: current perspectives

    Directory of Open Access Journals (Sweden)

    Tai XY

    2015-07-01

    Full Text Available Xin You Tai, Amit BatlaUCL Institute of Neurology, Queen Square, London, UKAbstract: Based on original descriptions of brain calcification by Theodor Fahr, brain calcification, and more specifically basal ganglia calcification, is referred to as Fahr's syndrome. Recent identification of genetic mutations has concerted the description of this erstwhile heterogeneous condition which we refer to here as Fahr's disease. Fahr's disease refers to idiopathic calcification of the basal ganglia without a secondary (non-genetic cause. Idiopathic basal ganglia calcification (IBGC is another term, which offers a more accurate description of this condition. Within the last 2 years, genetic mutations for IBGC have been described in SLC20A2, PDGFB, and PDGFRB. These findings broaden our understanding of the pathophysiology and encourage a search for specific treatment options in this rare but disabling condition. Clinically, parkinsonism, dystonia, and other movement disorders are the most common clinical features, but psychiatric features can predominate. Cases with confirmed genetic mutations reveal new clinical features linked with Fahr's disease, such as headaches. Computed tomography or magnetic resonance imaging is usually the trigger for suspecting Fahr's disease and important for identifying the calcification pattern. Symmetric calcification of the globus pallidus, thalamus, and dentate nucleus is the most common pattern in IBGC, but other parts of the brain such as the cerebellum are involved. Treatment of Fahr's disease is currently limited and is largely symptomatic. A better understanding of this condition in light of genetic findings is important to improve the clinical diagnosis and develop specific treatment options.Keywords: Fahr's disease, basal ganglia calcification, parkinsonism, calcium

  5. Galvanic currents and hydrogen permeation currents caused by galvanic coupling

    International Nuclear Information System (INIS)

    This paper reports on galvanic coupling and hydrogen permeation experiments performed in a Devanathan-Stachurski cell to measure simultaneously the galvanic currents and the hydrogen permeation currents in an attempt to determine the extent of hydrogen charging into noble metals as a result of galvanic coupling. Large amounts of hydrogen permeated through the more noble element of the couple. The magnitude of the hydrogen permeation flux varied depending on the galvanic coupling conditions. No simple direct relationship between galvanic currents and hydrogen permeation currents was observed, although large hydrogen permeation currents were usually developed whenever large galvanic currents were established

  6. Current profile control for high bootstrap current operation in ITER

    International Nuclear Information System (INIS)

    For the achievement of steady-state fusion power plant, non-inductively current-driven plasma operation should be maintained in tokamak fusion reactors. Total non-inductive current is a summation of bootstrap current proportional to the plasma pressure gradient and externally driven non-inductive current such as neutral beam driven current. Especially in order to establish a commercial reactor, it is necessary to reduce the amount of external current-drive power and to maintain the majority of the plasma current with bootstrap current. Burning plasma has high autonomy, so the change in current density profile including changes in particle and heat transports should be checked. In this study time-evolution analysis of the current density profile for burning plasmas in the ITER machine has been conducted by using 2.0-dimensional equilibrium, 1.5-dimensional-transport code (TOTAL code). Here current-diffusive ballooning mode model was adopted as a heat transport model. It is concluded that external current-drive is required both in the center and near the periphery of the plasma in order to maintain steady-state profiles of temperature and density with high bootstrap current fraction. (author)

  7. 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.

  8. Current Issues in Cosmology

    International Nuclear Information System (INIS)

    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

  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. Combined RF current drive and bootstrap current in tokamaks

    International Nuclear Information System (INIS)

    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. (c) 1999 American Institute of Physics

  11. Extreme current measurements using a fibre optics current sensor

    OpenAIRE

    Briffod, F.; Alasia, D.; Thévenaz, Luc; Cuenoud, G.; Robert, Ph

    2002-01-01

    We demonstrate that an optical fibre current sensor can measure current over 500 kA with an accuracy of 0.2%. This level of accuracy has never previously been achieved using a traditional non-optical sensor

  12. Experimental observation of neoclassical currents

    International Nuclear Information System (INIS)

    The parallel and perpendicular equilibrium currents have been experimentally studied in the Levitated Octupole, with toroidal field. Observations of the spatial structure, collisionality and toroidal field dependence of the complete current and the ion portion of the current are presented. Experimentally measured currents are compared to neoclassical current distributions calculated for the actual machine geometry. Measurements of the total plasma parallel current for absolute-MHD-stable flux surfaces (inside the separatrix) agree well with theory, showing the bootstrap and Pfirsch-Schlueter currents as predicted by neoclassical transport theory. On average-MHD-stable flux surfaces (outside the separatrix) there is more parallel current than predicted by theory, though the spatial structure is correct. Separate measurements of the ion parallel and perpendicular currents agree with theory, showing the lack of measurable ion poloidal rotation in all situations

  13. Eddy current testing by uniform eddy current probe

    International Nuclear Information System (INIS)

    The authors propose a new eddy current probe inducing uniform eddy current in the test material. The features of the probe are self-differential, lift-off noise free, and self-nulling in principle. The experimental results have shown that the probe has a promising possibility of applying eddy current testing to weld zones.

  14. Parity-violating asymmetry in d(vector e,e)np and measurement of the axial vector form factor at Q2= 0.23 (GeV/c)2

    International Nuclear Information System (INIS)

    The A4 collaboration at the MAMI facilities has measured the parity-violating asymmetry in the quasi-elastic scattering of longitudinally polarized electron on deuteron at backward angles and at a four momentum transfer of Q2=0.23 (GeV/c)2. This measurement is sensitive to a linear combination of the strange magnetic vector form factor GMs and the axial form factor GA. Combined with the measurement of the parity-violating asymmetry on proton at backwards and at the same four momentum transfer it allows the experimental determination of the axial form factor GA.

  15. Charm current-current correlators in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    The current correlator method has been shown to be a practical tool to extract the charm quark mass and strong coupling constant from Lattice QCD data as an alternative to the sum rule approach using experimental electron-positron annihilation cross section data. We report on the progress of an investigation of charm current-current correlators in Nf=2 Twisted Mass Lattice QCD. Upon determining the temporal moments of the current correlators we compare to the low-energy expansion of the moments in perturbative QCD and calculate the charm quark mass and strong coupling constant and in case of the vector current correlator directly compare both methods. (orig.)

  16. Steering Multiple Reverse Current into Unidirectional Current in Deterministic Ratchets

    Institute of Scientific and Technical Information of China (English)

    韦笃取; 罗晓曙; 覃英华

    2011-01-01

    Recent investigations have shown that with varying the amplitude of the external force, the deterministic ratchets exhibit multiple current reversals, which are undesirable in certain circumstances. To control the multiple reverse current to unidirectional current, an adaptive control law is presented inspired from the relation between multiple reversaJs current and the chaos-periodic/quasiperiodic transition of the transport velocity. The designed controller can stabilize the transport velocity of ratchets to steady state and suppress any chaos-periodic/quasiperiodic transition, namely, the stable transport in ratchets is achieved, which makes the current sign unchanged.

  17. 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...

  18. Representations of twisted current algebras

    OpenAIRE

    Lau, Michael

    2013-01-01

    We use evaluation representations to give a complete classification of the finite-dimensional simple modules of twisted current algebras. This generalizes and unifies recent work on multiloop algebras, current algebras, equivariant map algebras, and twisted forms.

  19. Exchange currents in nuclear physics

    International Nuclear Information System (INIS)

    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

  20. Conformal symmetry limit of QED and QCD and identities between perturbative contributions to deep-inelastic scattering sum rules

    International Nuclear Information System (INIS)

    Conformal symmetry-based relations between concrete perturbative QED and QCD approximations for the Bjorken , the Ellis-Jaffe sum rules of polarized lepton- nucleon deep-inelastic scattering (DIS), the Gross-Llewellyn Smith sum rules of neutrino-nucleon DIS, and for the Adler functions of axial-vector and vector channels are derived. They result from the application of the operator product expansion to three triangle Green functions, constructed from the non-singlet axial-vector, and two vector currents, the singlet axial-vector and two non-singlet vector currents and the non-singlet axial-vector, vector and singlet vector currents in the limit, when the conformal symmetry of the gauge models with fermions is considered unbroken. We specify the perturbative conditions for this symmetry to be valid in the case of the U(1) and SU(Nc) models. The all-order perturbative identity following from the conformal invariant limit between the concrete contributions to the Bjorken, the Ellis-Jaffe and the Gross-Llewellyn Smith sum rules is proved. The analytical and numerical O(α4) and O(αs2) conformal symmetry based approximations for these sum rules and for the Adler function of the non-singlet vector currents are summarized. Possible theoretical applications of the results presented are discussed

  1. Study of eddy current probes

    Science.gov (United States)

    Workman, Gary L.; Wang, Morgan

    1992-01-01

    The recognition of materials properties still presents a number of problems for nondestructive testing in aerospace systems. This project attempts to utilize current capabilities in eddy current instrumentation, artificial intelligence, and robotics in order to provide insight into defining geometrical aspects of flaws in composite materials which are capable of being evaluated using eddy current inspection techniques.

  2. Tokamak equilibria with nearly zero central current: the current hole

    International Nuclear Information System (INIS)

    The observation of stable sustainment of the 'current hole', namely the nearly zero current density region in the central part of a tokamak plasma, has opened a new class of configurations in tokamak plasmas, and a variety of research from the viewpoints of equilibrium, magnetohydrodynamics (MHD) stability, particle orbits and radial transport has been generated. Some theories and codes have been tested and extended by being applied to extreme conditions in the current hole with very weak poloidal field. The current hole is generated due to a transient negative toroidal electric field established when a large off-axis non-inductive current is rapidly formed. It has been observed in high confinement plasmas with a large fraction of bootstrap current in advanced tokamak operation. The current hole is very stiff against current drive, which suggests that it is a saturated or self-organized system. Appearance of the current hole in ITER and DEMO would be expected in some of the operation scenarios, and its influence and its control methods have been studied. Results of experimental and theoretical studies on the current hole are reviewed. (review article)

  3. Flow tracing based on current

    Institute of Scientific and Technical Information of China (English)

    蔡兴国; 曹海龙

    2001-01-01

    Analyses the flow tracing based on power flow, points out that the detachment of reactive power and active power is unrealiable and concludes that the current is the real basic of flow tracing,and proposes the new flow tracing model based on current, which devides the current into active current and reactive current, analyses the theory about the matrix to deal with the precision and realization of the flow tracing, and then proposes a new pricing model by fixed rate and marginal rate, which keeps not only economy information such as congestion cost in marginal cost based pricing, but also benefits to make both ends meet.

  4. HLS bunch current measurement system

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Bunch current is an important parameter for studying the injection fill-pattern in the storage ring and the instability threshold of the bunch, and the bunch current monitor also is an indispensable tool for the top-up injection. A bunch current measurement (BCM) system has been developed to meet the needs of the upgrade project of Hefei Light Source (HLS). This paper presents the layout of the BCM system. The system based on a high-speed digital oscilloscope can be used to measure the bunch current and synchronous phase shift. To obtain the absolute value of bunch-by-bunch current, the calibration coefficient is measured and analyzed. Error analysis shows that the RMS of bunch current is less than 0.01 mA when bunch current is about 5 mA, which can meet project requirement.

  5. Direct Current Contamination of Kilohertz Frequency Alternating Current Waveforms

    OpenAIRE

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

    2014-01-01

    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- a...

  6. Conformal symmetry limit of QED and QCD and the identities between the concrete perturbative contributions to deep-inelastic scattering sum rules

    CERN Document Server

    Kataev, A L

    2013-01-01

    Conformal symmetry based relations between the concrete perturbative QED and QCD approximations of the polarized Bjorken, the Ellis-Jaffe, the Gross-Llewellyn Smith sum rules and of the Adler functions of the axial vector and vector channels are derived. They are based on application of the operator product expansion to three triangle AVV Green functions, constructed from the non-singlet axial vector-vector-vector currents, the {\\it singlet} axial-vector and two {\\it non-singlet} vector currents and the {\\it non-singlet} axial-vector-vector and {\\it singlet} vector currents, in the limit when the conformal symmetry of gauge models with fermions is unbroken. We specify the conditions when the conformal symmetry is valid in the U(1) and $SU(N_c)$ models. The identity between perturbative approximations of the Bjorken, Ellis-Jaffe and the Gross-Llewellyn Smith sum rules, which follow from this theoretical limit, is proved. The expressions for the $O(\\alpha^4)$ and $O(\\alpha_s^3)$ conformal symmetry based contrib...

  7. Ionization tube simmer current circuit

    Science.gov (United States)

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  8. Black-hole eddy currents

    International Nuclear Information System (INIS)

    We study dissipative test electromagnetic fields in a black-hole background. Quantities such as surface velocity, tangential electric field, normal magnetic induction, total surface current, and conduction surface current are introduced and are shown to satisfy Ohm's law with a surface resistivity of 4π approx. = 377 ohms. Associated with these currents there exists a ''Joule heating''. These currents can exist when the black hole is inserted in an external electric circuit, but they can exist even in the absence of external currents. In particular, we study the eddy currents induced by the rotation of a black hole in an oblique uniform magnetic field, and we show how the computation of the ohmic losses allows a very simple derivation of the torque exerted on the hole

  9. Buoyancy driven rotating boundary currents

    CERN Document Server

    Yecko, P A

    1997-01-01

    The structure of boundary currents formed from intermediately dense water introduced into a rotating, stably stratified, two-layer environment is investigated in a series of laboratory experiments, performed for Froude numbers ranging from 0.01 to 1. The thickness and streamwise velocity profiles in quasi-steady currents are measured using a pH activated tracer (thymol blue) and found to compare favorably to simplified analytic solutions and numerical models. Currents flowing along sloping boundaries in a stratified background exhibit robust stability at all experimental Froude numbers. Such stability is in sharp contrast to the unequivocal instability of such currents flowing against vertical boundaries, or of currents flowing along slopes in a uniform background. The presence of a variety of wave mechanisms in the ambient medium might account for the slower and wider observed structures and the stability of the currents, by effecting the damping of disturbances through wave radiation.

  10. Bootstrap current in a tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, C.E.

    1994-03-01

    The bootstrap current in a tokamak is examined by implementing the Hirshman-Sigmar model and comparing the predicted current profiles with those from two popular approximations. The dependences of the bootstrap current profile on the plasma properties are illustrated. The implications for steady state tokamaks are presented through two constraints; the pressure profile must be peaked and {beta}{sub p} must be kept below a critical value.

  11. Bootstrap current in a tokamak

    International Nuclear Information System (INIS)

    The bootstrap current in a tokamak is examined by implementing the Hirshman-Sigmar model and comparing the predicted current profiles with those from two popular approximations. The dependences of the bootstrap current profile on the plasma properties are illustrated. The implications for steady state tokamaks are presented through two constraints; the pressure profile must be peaked and βp must be kept below a critical value

  12. 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.

  13. Current Research Information in Europe

    OpenAIRE

    van Dijk, A.; GreyNet, Grey Literature Network Service

    1994-01-01

    Current Research Information is defined here as descriptive information on ongoing scientific research (who, what, where). When a research project has started, the outside world can generally find information about it in Current Research information sources, then in the GL and towards the end of the project in the white literature. Compared to bibliographic databases, Current Research databases are searched by only a limited group of users. To enhance usage of this type of information, two po...

  14. Currents in the cometary atmosphere

    Science.gov (United States)

    Ip, W.-H.

    1979-01-01

    If the structure of the magnetic field and electric current in the cometary type I tail can be represented by an electric current circuit, disruption of the cross-tail current system may lead to a current discharging through the cometary ionosphere, and the dissipation of the magnetic energy stored in the tail. From the point of view of energy budget, a tail-aligned magnetic field on the order of 10 gamma will be sufficient to produce a strong ionization effect of the cometary atmosphere.

  15. Current Distribution Mapping for PEMFCs

    International Nuclear Information System (INIS)

    A developed measurement system for current distribution mapping has enabled a new approach for operational measurements in proton exchange membrane fuel cells (PEMFCs). Currently, there are many issues with the methods to measure current distribution; some of the problems that arise are breaking up the fuel cell component and these measurements are costly. Within this field of work, there is a cost effective method and an easy technique of mapping the current distribution within a fuel cell while not disrupting reactant flow. The physical setup of this method takes a current distribution board and inserts it between an anode flow field plate and a gas diffusion layer. From this layout, the current distribution can be directly measured from the current distribution board. This novel technique can be simply applied to different fuel cell hardware. Further it also can be used in fuel cell stack by inserting multiple current distribution boards into the stack cells. The results from the current distribution measurements and the electrochemical predictions from computational fluid dynamics modeling were used to analyze water transports inside the fuel cell. This developed system can be a basis for a good understanding of optimization for fuel cell design and operation mode

  16. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    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)

  17. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    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. PMID:26805830

  18. Nuclear Current and Magnetic Rotation

    Institute of Scientific and Technical Information of China (English)

    PENG Jing; XING Li-Feng

    2009-01-01

    The magnetic rotational bands based on the configuration πh211/2 ⊕Vh-211/2 in 142 Gd are investigated with the newly developed tilted axis cranking relativistic mean field (RMF) theory with and without nuclear current.The effect of the nuclear current is discussed by comparing the total Routhians,single particle levels,electromagnetic transition probabilities B(M1) and B(E2) in self-consistent tilted axis cranking RMF calculation with those obtained without the nuclear current.The nuclear currents are found to play an important role in the magnetic rotation of nuclei.

  19. Estimates of the Nucleon Tensor Charge

    CERN Document Server

    Gamberg, L P; Gamberg, Leonard; Goldstein, Gary R.

    2001-01-01

    Like the axial vector charges, defined from the forward nucleon matrix element of the axial vector current on the light cone, the nucleon tensor charge, defined from the corresponding matrix element of the tensor current, is essential for characterizing the momentum and spin structure of the nucleon. Because there must be a helicity flip of the struck quark in order to probe the transverse spin polarization of the nucleon, the transversity distribution (and thus the tensor charge) decouples at leading twist in deep inelastic scattering, although no such suppression appears in Drell-Yan processes. This makes the tensor charge difficult to measure and its non-conservation makes its prediction model dependent. We present a different approach. Exploiting an approximate SU(6)xO(3) symmetric mass degeneracy of the light axial vector mesons (a1(1260), b1(1235) and h1(1170)) and using pole dominance, we calculate the tensor charge. The result is simple in form and depends on the decay constants of the axial vector me...

  20. Anomalous-viscosity current drive

    Science.gov (United States)

    Stix, T.H.; Ono, M.

    1986-04-25

    The present invention relates to a method and apparatus for maintaining a steady-state current for magnetically confining the plasma in a toroidal magnetic confinement device using anomalous viscosity current drive. A second aspect of this invention relates to an apparatus and method for the start-up of a magnetically confined toroidal plasma.

  1. Eddy current manual, volume 2

    International Nuclear Information System (INIS)

    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

  2. Multispacecraft current estimates at swarm

    DEFF Research Database (Denmark)

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

    2015-01-01

    orbit the use oftime-shifted positions allow stable estimates of current density to be made and can verify temporal effects aswell as validating the interpretation of the current components as arising predominantly from field-alignedcurrents. In the case of four-spacecraft configurations we can resolve...

  3. Magnetic Materials for Current Transformers

    CERN Document Server

    Aguilera, S; Ruffieux, P

    2013-01-01

    At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a vari...

  4. Second class currents and nuclei

    International Nuclear Information System (INIS)

    A theoretical analysis of the recent experimental data relevant to second-class currents is made on the basis of the effective two-body operator approach proposed several years ago by the present authors. It takes into account nuclear many-body effects such as off-the-energy-shell and meson-exchange effects. The previous results indicating the presence of second-class currents comparable in their magnitudes to the weak magnetism term are altered. Next, we suggest that mesonic effects on the time-component of first-class axial current can be tested unambiguously. The argument is based on the low-energy theorem and model-independent to great degree. We emphasize that further correlation experiments are highly desirable not only for testing the second-class currents but also making a clean test of the mesonic effects on axial current. (author)

  5. Relationships between Geomagnetic Induced Currents and Field Aligned Currents

    Science.gov (United States)

    Waters, C. L.; Barnett, R.; Anderson, B. J.; Gjerloev, J. W.; Korth, H.; Barnes, R. J.

    2015-12-01

    Geomagnetic Induced Currents (GICs) appear in the ground due to time varying magnetic fields that occur during periods of enhanced geomagnetic activity. The resultant time varying electric fields at Earth's surface drive very low frequency, currents through electricity supply transformers which reduces transforming capacity. In extreme cases, electricity supply grids can collapse as multiple transformers are affected. GICs have larger magnitudes at auroral latitudes and should be related to the field aligned current (FAC) and auroral ionosphere currents systems. At ground locations under the regions between upward and downward FACs, the GIC related fields show a direct relationship with the time derivative of the FACs. This allows a conversion factor between FAC and GIC magnitudes. Examples of the relationship between FAC and GIC related fields are presented using data derived from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) and SuperMAG.

  6. 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%.

  7. Spatial current patterns, dephasing and current imaging in graphene nanoribbons

    International Nuclear Information System (INIS)

    Using the non-equilibrium Keldysh Green's function formalism, we investigate the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In particular, we demonstrate that the spatial current patterns associated with discrete transmission resonances sensitively depend on the GNRs' geometry, size and aspect ratio, the location and number of leads and the presence of dephasing. We identify a relation between the spatial form of the current patterns, and the number of degenerate energy states participating in the charge transport. Furthermore, we demonstrate a principle of superposition for the conductance and spatial current patterns in multiple-lead configurations. We demonstrate that scanning tunneling microscopy can be employed to image spatial current paths in GNRs with atomic resolution, providing important insight into the form of local charge transport. Finally, we investigate the effects of dephasing on the spatial current patterns, and show that with decreasing dephasing time, the current patterns evolve smoothly from those of a ballistic quantum network to those of a classical resistor network. (paper)

  8. The bootstrap current in tokamaks

    International Nuclear Information System (INIS)

    The properties of the Hirshman equation for the bootstrap in the tokamak and the difference between it and the simpler Hinton-Hazeltine equation are discussed. The Hirshman model, which takes into account finite-aspect-ratio effects, is used to calculate the bootstrap current in the plasma in a circular cross section with Te = Ti. Approximate upper and lower bounds on the bootstrap current are obtained. These restrict the range of variation of the current as the temperature and density profiles vary. 16 refs., 9 figs

  9. Lightning current waveform measuring system

    Science.gov (United States)

    Wojtasinski, R. J.; Fuchs, J. C.; Grove, C. H. (Inventor)

    1978-01-01

    An apparatus is described for monitoring current waveforms produced by lightning strikes which generate currents in an elongated cable. These currents are converted to voltages and to light waves for being transmitted over an optical cable to a remote location. At the remote location, the waves are reconstructed back into electrical waves for being stored into a memory. The information is stored within the memory with a timing signal so that only different signals need be stored in order to reconstruct the wave form.

  10. Current in open quantum systems.

    Science.gov (United States)

    Gebauer, Ralph; Car, Roberto

    2004-10-15

    We show that a dissipative current component is present in the dynamics generated by a Liouville-master equation, in addition to the usual component associated with Hamiltonian evolution. The dissipative component originates from coarse graining in time, implicit in a master equation, and needs to be included to preserve current continuity. We derive an explicit expression for the dissipative current in the context of the Markov approximation. Finally, we illustrate our approach with a simple numerical example, in which a quantum particle is coupled to a harmonic phonon bath and dissipation is described by the Pauli master equation. PMID:15524960

  11. 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.

  12. 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...

  13. Electric current abroad, 1991 edition

    Science.gov (United States)

    1991-07-01

    The characteristics are listed, for the information of U.S. manufacturers and exporters and individuals living or traveling abroad, of electric current available and the type of attachment plugs used in principal cities throughout the world. The characteristics of electric current-type (alternating or direct current), number of phases, frequency (hertz), and voltage found in major foreign cities are listed. In addition, the stability of the frequency and the number of wires to a commercial or residential installation are given where available. The current characteristics and other data furnished relate to domestic and commercial service only. It does not include special commercial installations involving relatively high voltage requirements nor does it refer to any industrial installations.

  14. Electric Current Abroad, 1991 Edition

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

    The publication lists, for the information of U.S. manufacturers and exporters and individuals living or traveling abroad, the characteristics of electric current available and the type of attachment plugs used in principal cities throughout the world. The characteristics of electric current-type (alternating or direct current), number of phases, frequency (hertz), and voltage-found in major foreign cities are listed. In addition, the stability of the frequency and the number of wires to a commercial or residential installation are given where available. The current characteristics and other data furnished relate to domestic and commercial service only. It does not include special commercial installations involving relatively high voltage requirements nor does it refer to any industrial installations.

  15. 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...

  16. Current Vaccine Shortages and Delays

    Science.gov (United States)

    ... CDC.gov . Vaccines and Immunizations Share Compartir Current Vaccine Shortages & Delays Last Updated December 7, 2015 On ... schedule are included in this update. Chart of Vaccines* in Delay or Shortage Vaccines are listed in ...

  17. Magneto-optic current sensor

    Science.gov (United States)

    Lanagan, Michael T.; Valsko-Vlasov, Vitalii K.; Fisher, Brandon L.; Welp, Ulrich

    2003-10-07

    An optical current transducer configured to sense current in the conductor is disclosed. The optical current transducer includes a light source and a polarizer that generates linearly polarized light received from a the light source. The light is communicated to a magneto-optic garnet that includes, among other elements, bismuth, iron and oxygen and is coupled to the conductor. The magneto-optic garnet is configured to rotate the polarization of the linearly polarized light received from the polarizer. The optical current transducer also includes an analyzer in optical communication with the magneto-optic garnet. The analyzer detects the rotation of the linearly polarized light caused by the magneto-optic garnet.

  18. High current gain transistor laser

    Science.gov (United States)

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-06-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge.

  19. Five currents of organizational psychology

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2016-01-01

    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...

  20. 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...

  1. Superconducting dc fault current limiter

    International Nuclear Information System (INIS)

    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)

  2. Surface Electromigration and Current Crowding

    Science.gov (United States)

    Yongsunthon, R.; Tao, C.; Rous, P.; Williams, E. D.

    Steps on macroscopic surfaces provide a useful model system for quantifying electron scattering at defects in nanostructures, where the large surface/volume ratio will cause surface effects to dominate. Here, the effects of electron scattering at surface steps are quantified using thin silver films with (111) surface orientation. Using real-time scanning tunneling microscopy (STM) measurements while large current densities are applied to the films, changes in step fluctuations and island motion are observed and quantified. Applying the tools of the continuum step model, the observations are analyzed in terms of step free energies and kinetics, yielding quantitative values of the electromigration force driving the observed mass displacements. The derived magnitudes are surprisingly large in comparison with classical calculations of the force due to electron scattering at the internal surface of a conductor. This result indicates that the specific atomistic characteristics of the scattering sites, in this case kinks at the step edge, may greatly enhance the electromigration force. Within the classical ballistic picture of ballistic momentum transfer, specific mechanisms for such enhancement include enhanced geometric "blocking" at the kinked step edges, changes in carrier density near kinks, and current crowding. Quantum transmission effects at atomic-scale defect sites may also be responsible for the observed enhancement. The nature of classical current crowding as a function of the shape and size of defect was characterized using magnetic force microscopy (MFM) of fabricated micron-scale model structures. Techniques were developed to remove the effects of instrumental broadening using deconvolution, so that full three-dimensional maps of the magnetic fields above the current line are determined. A Green function inversion technique is then used to invert the field distribution to determine the spatial variations in the current density in the sample. Current

  3. 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.)

  4. Imposed currents in galvanic cells

    OpenAIRE

    Biesheuvel, P.M.; van 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 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...

  5. Current devices of respiratory physiotherapy

    OpenAIRE

    Hristara-Papadopoulou, A; Tsanakas, J; Diomou, G; Papadopoulou, O.

    2008-01-01

    In recent years patients with respiratory diseases use various devices, which help the removal of mucus from the airways and the improvement of pulmonary function. The aim of the present study is to determine the effectiveness of the current devices of respiratory physiotherapy, as it comes from the review of literature. The current devices of physiotherapy for patients with respiratory diseases, are presented as an alternative therapy method or a supplemental therapy and they can motivate pa...

  6. Transcutaneous Spinal Direct Current Stimulation

    OpenAIRE

    Cogiamanian, Filippo; Ardolino, Gianluca; Vergari, Maurizio; Ferrucci, Roberta; Ciocca, Matteo; Scelzo, Emma; Barbieri, Sergio; Priori, Alberto

    2012-01-01

    In the past 10 years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability (“brain polarization” or transcranial direct current stimulation, tDCS). Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation. Aiming at developing a new, non-invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stim...

  7. The bivariate current status model

    OpenAIRE

    Groeneboom, P.

    2013-01-01

    For the univariate current status and, more generally, the interval censoring model, distribution theory has been developed for the maximum likelihood estimator (MLE) and smoothed maximum likelihood estimator (SMLE) of the unknown distribution function, see, e.g., [12], [7], [4], [5], [6], [10], [11] and [8]. For the bivariate current status and interval censoring models distribution theory of this type is still absent and even the rate at which we can expect reasonable estimators to converge...

  8. Josephson Persistent-Current Qubit

    OpenAIRE

    Mooij, J. E.; Orlando, T. P.; Levitov, L.; Tian , Lin; van der Wal, Caspar H.; Lloyd, Seth

    1999-01-01

    A qubit was designed that can be fabricated with conventional electron beam lithography and is suited for integration into a large quantum computer. The qubit consists of a micrometer-sized loop with three or four Josephson junctions; the two qubit states have persistent currents of opposite direction. Quantum superpositions of these states are obtained by pulsed microwave modulation of the enclosed magnetic flux by currents in control lines. A superconducting flux transporter allows for cont...

  9. Submesoscale currents in the ocean

    OpenAIRE

    Mcwilliams, James C.

    2016-01-01

    This article is a perspective on the recently discovered realm of submesoscale currents in the ocean. They are intermediate-scale flow structures in the form of density fronts and filaments, topographic wakes and persistent coherent vortices at the surface and throughout the interior. They are created from mesoscale eddies and strong currents, and they provide a dynamical conduit for energy transfer towards microscale dissipation and diapycnal mixing. Consideration is given to their generatio...

  10. CURRENT ACCOUNTING DEVELOPMENTS IN KOSOVO

    OpenAIRE

    NEXHMIE VOKSHI; MIHANE BERISHA-NAMANI

    2011-01-01

    For the study of the developments in accounting in Kosovo and its prospects, it is necessary to review the current situation of the developments in accounting, the recognition and acceptance of accounting standards. It is clear that the actual and perspective development level in an affected by many factors, such as social, cultural, etc. Therefore, the main aim of the research work in this study is to give an overview of the current developments of accounting in Kosovo. To obtain the require...

  11. High temperature superconductor current leads

    International Nuclear Information System (INIS)

    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

  12. 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

  13. Digitally compensated beam current transformer

    CERN Document Server

    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 645ns "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 less than 1 ns rise time and droops of 0.1 %/ms. This places a significant design burden on the cur...

  14. 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.

  15. Current pulse shaping of the load current on PTS

    Science.gov (United States)

    Xia, Minghe; Li, Fengping; Ji, Ce; Wei, Bing; Feng, Shuping; Wang, Meng; Xie, Weiping

    2016-02-01

    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.

  16. 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.

  17. Current disruption in toroidal devices

    International Nuclear Information System (INIS)

    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)

  18. Turbulent lock release gravity current

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The time evolution of a turbulent lock release gravity current, formed by a finite volume ofhomogeneous fluid released instantaneously into another fluid of slightly lower density, was studied byexperimental measurements of the density structure via elaborate digital image processing and by a nu-merical simulation of the flow and mixing using a two-equation turbulence model. The essential fact thatthe gravity current passes through an initial slumping phase in which the current head advances steadilyand a second self-similar phase in which the front velocity decreases like the negative third power of thetime after release is satisfactorily presented by the laboratory observation. An overall entrainment ratioproportional to the distance from the release point is found by the numerical simulation. The renormal-ization group (RNG) k- ε model for Reynolds-stress closure is validated to characterize the gravitycurrent with transitional and localized turbulence.

  19. Current Conservation in Nonequilibrium Networks

    International Nuclear Information System (INIS)

    Full text: In contrast to the well-known Chalker-Coddington network model, which uses elastic single particle quantum tunneling at saddle points to obtain critical exponents, the nonequilibrium network model describes quantities of nonequilibrium thermodynamics by using the Landauer-Buettiker approach. In case of local linear transport at saddles we show that the chemical potential distribution can be obtained, respecting the boundary condition of injected currents, from an inhomogeneous system of linear equations. It turns out that the solution is uniquely determined by the boundary condition, no matter how many current contacts we have. The seeming contradiction can be resolved by the fact that current is automatically conserved in the network. (author)

  20. Current therapies for premature ejaculation.

    Science.gov (United States)

    Gur, Serap; Kadowitz, Philip J; Sikka, Suresh C

    2016-07-01

    Premature ejaculation (PE) subjectively affects 20-30% of men globally. Until recently, understanding of PE was hampered by the absence of a widely accepted definition, paucity of evidence-based clinical studies, and the absence of an appropriate animal model. Here, we elaborate on the current definition of PE, its pathogenesis, currently available therapies, and future treatment prospects. Most treatments for PE are 'off-label' and include selective serotonin reuptake inhibitors (SSRIs), topical anesthetics, tramadol, and phosphodiesterase type 5 (PDE5) inhibitors. Such knowledge of the benefit and limitations of each treatment will help to direct future drug design and formulations. PMID:27179987

  1. Force As A Momentum Current

    International Nuclear Information System (INIS)

    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.

  2. Eddy current inspection of tubing

    International Nuclear Information System (INIS)

    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. Transungual drug delivery: current status.

    Science.gov (United States)

    Elkeeb, Rania; AliKhan, Ali; Elkeeb, Laila; Hui, Xiaoying; Maibach, Howard I

    2010-01-15

    Topical therapy is highly desirable in treating nail disorders due to its localized effects, which results in minimal adverse systemic events and possibly improved adherence. However, the effectiveness of topical therapies is limited by minimal drug permeability through the nail plate. Current research on nail permeation that focuses on altering the nail plate barrier by means of chemical treatments, penetration enhancers as well as physical and mechanical methods is reviewed. A new method of nail sampling is examined. Finally limitations of current ungual drug permeability studies are briefly discussed. PMID:19819318

  4. Current issues with research support

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W.T.

    1996-03-01

    It would be difficult to condense current issues in nuclear reactor regulation to just a few minutes. So, let me start off by saying that I have not tried to give a comprehensive listing of issues that are currently facing the reactor program, but rather to select those that I thought were relevant as they relate to research activities. Use of probabilistic risk assessment in regulatory decisions; materials aging issues concerning steam generators and reactor vessels; high burnup fuels; accident management; and digital instrumentation and control, are just a sampling of the important issues that I want to talk about.

  5. 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.

  6. Nondestructive synchronous beam current monitor

    International Nuclear Information System (INIS)

    A fast current transformer is mounted after the deflectors of the Berkeley 88-Inch Cyclotron. The measured signal is amplified and connected to the input of a lock-in amplifier. The lock-in amplifier performs a synchronous detection of the signal at the cyclotron second harmonic frequency. The magnitude of the signal detected is calibrated against a Faraday cup and corresponds to the beam intensity. It has exceptional resolution, long term stability, and can measure the beam current leaving the cyclotron as low as 1 nA

  7. Current trends and future directions

    DEFF Research Database (Denmark)

    Harboe, Peter G.; Madsen, Sabine; Svejvig, Per

    2012-01-01

    This book is an attempt to gather current state-of-the-art research on project management from multiple universities and university colleges in Denmark. This chapter first discuss a literature review of Danish and Scandinavian research on project management thereby complementing the short review ...

  8. High-current cyclotron injector

    International Nuclear Information System (INIS)

    Choosing the parameters of a high-current cyclotron intended for production of 1-10 mA intensity beam is considered. The cyclotron is assumed to be used as an injector for deuteron accelerating facility to 45 MeV/nucleon energy. 13 refs.; 4 figs.; 1 tab

  9. Inexpensive Eddy-Current Standard

    Science.gov (United States)

    Berry, Robert F., Jr.

    1985-01-01

    Radial crack replicas serve as evaluation standards. Technique entails intimately joining two pieces of appropriate aluminum alloy stock and centering drilled hole through and along interface. Bore surface of hole presents two vertical stock interface lines 180 degrees apart. These lines serve as radial crack defect replicas during eddy-current technique setup and verification.

  10. Noether currents for BF gravity

    International Nuclear Information System (INIS)

    The conservation laws and currents for BF theory in four spacetime dimensions and BF gravity corresponding with their Lagrangian local gauge symmetries (local Lorentz transformations and diffeomorphisms) are computed using Noether's theorem. The physical meaning of the Noether charges that arise from the conservation laws is not explored

  11. Intelligence Current in Creative Activities

    Science.gov (United States)

    Shi, Jiannong

    2004-01-01

    In this paper, the term 'intelligence current' is further explained and the problems found in relationships between (among) creativity, intelligence, attitude and environmental factors are discussed, according to the systematic model of creativity previously developed by the author. In this model, the performance of an individual's creativity is…

  12. 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 ag

  13. Current Research in Affective Development.

    Science.gov (United States)

    Strayer, Janet

    1985-01-01

    Current research concerning affective development in infants and children is selectively reviewed. The focus of findings and discussion is on three general and related topics: (1) expression of emotion and affective interaction in infancy; (2) socialization and regulation of emotion; (3) comprehension of emotions and empathy with others by…

  14. 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 and...

  15. 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.

  16. Eddy current thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Gary J.; Sinclair, Frank; Soskov, Alexander; Buff, James S.

    2015-06-16

    A sheet of a material is disposed in a melt of the material. The sheet is formed using a cooling plate in one instance. An exciting coil and sensing coil are positioned downstream of the cooling plate. The exciting coil and sensing coil use eddy currents to determine a thickness of the solid sheet on top of the melt.

  17. The Current in a Wire

    Science.gov (United States)

    Thompson, Keith

    2009-01-01

    This little problem arose because I was frustrated with the standard electromagnetism texts, which show the magnetic field due to a current-bearing wire outside the wire [proportional to] 1/r and inside [proportional to] r. However, they never point out that the moving electrons must be influenced by the magnetic field created by the other moving…

  18. Eddy current manual: v.1

    International Nuclear Information System (INIS)

    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

  19. Eddy current testing, volume 1

    International Nuclear Information System (INIS)

    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

  20. 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...

  1. Current-Induced Membrane Discharge

    NARCIS (Netherlands)

    Baeko Andersen, M.; Soestbergen, M.; Mani, A.; Bruus, H.; Biesheuvel, P.M.; Bazant, M.Z.

    2012-01-01

    Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory neglects

  2. 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...

  3. Current management of oral cancer

    Institute of Scientific and Technical Information of China (English)

    Robert Ord

    2008-01-01

    @@ This presentation will summarize some of the current areas of interest in the management of oral cancer. The presentation will be divided into a brief review of epidemiology and diagnosis, with a more extensive discussion regarding the controversial areas in surgery and a review of the adjuvant roles of radiation and chemotherapy.

  4. Chiral Electroweak Currents in Nuclei

    CERN Document Server

    Riska, D O

    2016-01-01

    The development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown's role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.

  5. 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…

  6. Current controller for electron gun

    International Nuclear Information System (INIS)

    A beam-current controller for a triode electron gun is described that permits the voltage on the control electrode to be varied within 0-2.5 kV with 60-kV isolation of the output part of the circuit from the low-potential control-signal source. The carrier frequency for control-signal conversion is 32 khz

  7. The Current Conjuncture in Theory.

    Science.gov (United States)

    Sprinker, Michael

    1989-01-01

    Describes the current debate in literary study between the humanist/historicist and the anti-humanist/anti-historicist perspectives. Examines the political dimensions of this debate, including its relationship to Marxist theory and deconstruction. Asserts that literary texts are productions of ideology and that literary study should inquire into…

  8. Biodiesel: Current Trends and Properties

    Science.gov (United States)

    Biodiesel, an alternative to petroleum-derived diesel fuel, is defined as the mono-alkyl esters of vegetable oils and animal fats. Several current issues affecting biodiesel that are briefly discussed include the role of new feedstocks in meeting increased demand for biodiesel and circumventing the...

  9. Radiopharmaceuticals - current state and trends

    International Nuclear Information System (INIS)

    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)

  10. Plasma current profile shaping with rf-current drive

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, D.A.; Evans, K. Jr.

    1985-01-01

    Calculations of rf current drive in a toroidal geometry are presented. The result is self-consistent in that the tokamak magnetic field generated by the rf-driven current is used to compute the wave trajectory and spatial damping in the plasma. In the next section we derive the quasilinear theory in an axisymmetric torus. In Section 3 we describe a numerical solution to this problem and investigate rf-generated equilibria in a reactor-relevant geometry (A = 6.0; major radius, R/sub 0/ = 5.25 m; elongation k = 1.6; triangular boundary). By suitably adjusting the rf/plasma parameters a wide range of equilibria can be created. Although we have not optimized our rf-generated equilibria (in particular, we are limited at present to a narrow spectrum) we find evidence that equilibria can be sustained which should lead to attractive tokamak reactors.

  11. Formation of current density profile in tilted current sheets

    Directory of Open Access Journals (Sweden)

    A. A. Petrukovich

    2008-11-01

    Full Text Available We investigate Cluster observations of strongly tilted sheets (flapping events in the magnetotail. In accordance with the simple model of slip deformation (vertical differential displacement of neighboring flux tubes, the Jy current density component in the tilted sheet remains constant and equal to that in the horizontal undisturbed sheet. However, a substantial Jz component appears proportional to the local sheet tilt. Slip-type variations, having smaller scale than the full crossing, locally change the tilt and Jz and may thus create a variety of non-classical (bifurcated, asymmetric etc current density profiles.

  12. Power voltage current convertor using quasi complementary MOSFET current mirrors.

    Science.gov (United States)

    Maclachlan, R A; Riviere, C N

    2011-10-13

    A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. GΩ output impedance and distortion below 1% can be obtained with no trimming or transistor matching. PMID:22312182

  13. Imposed currents in galvanic cells

    International Nuclear Information System (INIS)

    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

  14. Bootstrap Current in Spherical Tokamaks

    Institute of Scientific and Technical Information of China (English)

    王中天; 王龙

    2003-01-01

    Variational principle for the neoclassical theory has been developed by including amomentum restoring term in the electron-electron collisional operator, which gives an additionalfree parameter maximizing the heat production rate. All transport coefficients are obtained in-cluding the bootstrap current. The essential feature of the study is that the aspect ratio affects thefunction of the electron-electron collision operator through a geometrical factor. When the aspectratio approaches to unity, the fraction of circulating particles goes to zero and the contribution toparticle flux from the electron-electron collision vanishes. The resulting diffusion coefficient is inrough agreement with Hazeltine. When the aspect ratio approaches to infinity, the results are inagreement with Rosenbluth. The formalism gives the two extreme cases a connection. The theoryis particularly important for the calculation of bootstrap current in spherical tokamaks and thepresent tokamaks, in which the square root of the inverse aspect ratio, in general, is not small.

  15. Superconducting currents from molecular theory

    International Nuclear Information System (INIS)

    The gauge-invariant method of London is used to solve the molecular orbital (MO) equations in a square planar slab, with one electron per site, in a perpendicular magnetic field. Pair currents appear because of the degeneracy and incomplete filling of highest occupied molecular orbital (HOMO). This type of electronic structure may alternatively result in an antiferromagnetic (AF) state of a charge density wave (CDW) state. The CDW state has alternating oxidation states which are different in two units, for example, in BaBiO3, where the valence state of Bi is alternating between +3 and +5, depending on whether the Bi6s2 electron pair is present at the site. The AF state, on the other hand, appears if only the middle valence state is stable. It is shown here that appearance of electron pair currents requires that all three oxidation states are at about the same total energy

  16. Current status of transarterial radioembolization.

    Science.gov (United States)

    Mahnken, Andreas H

    2016-05-28

    Unresectable primary and secondary liver malignancies present a major problem in the treatment of solid tumors. Transarterial radioembolization (TARE) is an increasingly used technique for treating various types of malignant liver tumors. This approach is appealing, as the mechanism of action is independent from other loco-regional treatments and potentially complementary to systemic therapies. There are two commercially available products in use for TARE: (90)Y-resin and (90)Y-glass microspheres. Currently available data indicates TARE so be safe and effective in hepatocellular carcinoma (HCC) and metastatic liver disease. In HCC the results compare well with chemoembolization, while the role of TARE in combination with kinase inhibitors has yet to be established. Current data on TARE in metastatic liver disease is promising, but there is a strong need for prospective randomized trials comparing TARE and modern chemotherapeutic regimen to support the growing role of TARE in metastatic liver disease. PMID:27247711

  17. 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.

  18. 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.

  19. Current Concept of Geometrical Accuracy

    Science.gov (United States)

    Görög, Augustín; Görögová, Ingrid

    2014-06-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutteŕs geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  20. Entropy current in conformal hydrodynamics

    International Nuclear Information System (INIS)

    In recent work [1, 2], the energy-momentum tensor for the N = 4 SYM fluid was computed up to second derivative terms using holographic methods. The aim of this note is to propose an entropy current (accurate up to second derivative terms) consistent with this energy-momentum tensor and to explicate its relation with the existing theories of relativistic hydrodynamics. In order to achieve this, we first develop a Weyl-covariant formalism which simplifies the study of conformal hydrodynamics. This naturally leads us to a proposal for the entropy current of an arbitrary conformal fluid in any spacetime (with d>3). In particular, this proposal translates into a definite expression for the entropy flux in the case of N = 4 SYM fluid. We conclude this note by comparing the formalism presented here with the conventional Israel-Stewart formalism.

  1. Current Concept of Geometrical Accuracy

    Directory of Open Access Journals (Sweden)

    Görög Augustín

    2014-06-01

    Full Text Available Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners. During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  2. Solid-state current transformer

    Science.gov (United States)

    Farnsworth, D. L. (Inventor)

    1976-01-01

    A signal transformation network which is uniquely characterized to exhibit a very low input impedance while maintaining a linear transfer characteristic when driven from a voltage source and when quiescently biased in the low microampere current range is described. In its simplest form, it consists of a tightly coupled two transistor network in which a common emitter input stage is interconnected directly with an emitter follower stage to provide virtually 100 percent negative feedback to the base input of the common emitter stage. Bias to the network is supplied via the common tie point of the common emitter stage collector terminal and the emitter follower base stage terminal by a regulated constant current source, and the output of the circuit is taken from the collector of the emitter follower stage.

  3. Current status of rotavirus vaccines

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

    Background: 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. Data sources: 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. Results: 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. Conclusions: 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.

  4. CURRENT ACCOUNTING DEVELOPMENTS IN KOSOVO

    Directory of Open Access Journals (Sweden)

    NEXHMIE VOKSHI

    2011-04-01

    Full Text Available For the study of the developments in accounting in Kosovo and its prospects, it is necessary to review the current situation of the developments in accounting, the recognition and acceptance of accounting standards. It is clear that the actual and perspective development level in an affected by many factors, such as social, cultural, etc. Therefore, the main aim of the research work in this study is to give an overview of the current developments of accounting in Kosovo. To obtain the required information, 400 respondents have been chosen through a questionnaire designed for this purpose1. The respondents operate in different branches, they work in small, medium and large enterprises, insurance companies, banks, and while some of them are independent accountants and employees in the tax authorities. The data obtained are processed and analyzed from two aspects: the aspect of descriptive statistics reflected through histograms, and econometric aspect of reflecting through econometric models.

  5. Current status of viroid taxonomy.

    Science.gov (United States)

    Di Serio, F; Flores, R; Verhoeven, J Th J; Li, S-F; Pallás, V; Randles, J W; Sano, T; Vidalakis, G; Owens, R A

    2014-12-01

    Viroids are the smallest autonomous infectious nucleic acids known so far. With a small circular RNA genome of about 250-400 nt, which apparently does not code for any protein, viroids replicate and move systemically in host plants. Since the discovery of the first viroid almost forty-five years ago, many different viroids have been isolated, characterized and, frequently, identified as the causal agents of plant diseases. The first viroid classification scheme was proposed in the early 1990s and adopted by the International Committee on Taxonomy of Viruses (ICTV) a few years later. Here, the current viroid taxonomy scheme and the criteria for viroid species demarcation are discussed, highlighting the main taxonomic questions currently under consideration by the ICTV Viroid Study Group. The impact of correct taxonomic annotation of viroid sequence variants is also addressed, taking into consideration the increasing application of next-generation sequencing and bioinformatics for known and previously unrecognized viroids. PMID:25216773

  6. Currents in supersymmetric field theories

    CERN Document Server

    Derendinger, Jean-Pierre

    2016-01-01

    A general formalism to construct and improve supercurrents and source or anomaly superfields in two-derivative N=1 supersymmetric theories is presented. It includes arbitrary gauge and chiral superfields and a linear superfield coupled to gauge fields. These families of supercurrent structures are characterized by their energy-momentum tensors and R currents and they display a specific relation to the dilatation current of the theory. The linear superfield is introduced in order to describe the gauge coupling as a background (or propagating) field. Supersymmetry does not constrain the dependence on this gauge coupling field of gauge kinetic terms and holomorphicity restrictions are absent. Applying these results to an effective (Wilson) description of super-Yang-Mills theory, matching or cancellation of anomalies leads to an algebraic derivation of the all-order NSVZ beta function.

  7. Current Concepts in ACL Reconstruction

    OpenAIRE

    Fu, Freddie H; Cohen, Steven B.

    2008-01-01

    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 con...

  8. Ultrasound Current Source Density Imaging

    OpenAIRE

    Olafsson, Ragnar; Witte, Russell S.; Huang, Sheng-Wen; O’Donnell, Matthew

    2008-01-01

    Surgery to correct severe heart arrhythmias usually requires detailed maps of the cardiac activation wave prior to ablation. The pinpoint electrical mapping procedure is laborious and limited by its spatial resolution (5–10 mm). We propose ultrasound current source density imaging (UCSDI), a direct 3-D imaging technique that potentially facilitates existing mapping procedures with superior spatial resolution. The technique is based on a pressure-induced change in resistivity known as the acou...

  9. Current concepts in maxillofacial imaging

    International Nuclear Information System (INIS)

    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

  10. Current Status of Graphene Transistors

    OpenAIRE

    Lemme, Max. C.

    2009-01-01

    This paper reviews the current status of graphene transistors as potential supplement to silicon CMOS technology. A short overview of graphene manufacturing and metrology methods is followed by an introduction of macroscopic graphene field effect transistors (FETs). The absence of an energy band gap is shown to result in severe shortcomings for logic applications. Possibilities to engineer a band gap in graphene FETs including quantum confinement in graphene Nanoribbons (GNRs) and electricall...

  11. Current forms and gauge invariance

    International Nuclear Information System (INIS)

    Let C be the bundle of connections of a principal G-bundle π:P → M, and let V be the vector bundle associated with P by a linear representation G → GL(V) on a finite-dimensional vector space V. The Lagrangians on J1(C x MV) whose current form is gauge invariant, are described and the gauge-invariant Lagrangians on J1(V) are classified

  12. Current therapy for Parkinson's disease

    OpenAIRE

    A. V. Obukhova

    2014-01-01

    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 o...

  13. 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...

  14. Current understanding of Pneumocystis immunology

    OpenAIRE

    Kelly, Michelle N; Shellito, Judd E.

    2010-01-01

    Pneumocystis jirovecii is the opportunistic fungal organism that causes Pneumocystis pneumonia (PCP) in humans. Similar to other opportunistic pathogens, Pneumocystis causes disease in individuals who are immunocompromised, particularly those infected with HIV. PCP remains the most common opportunistic infection in patients with AIDS. Incidence has decreased greatly with the advent of HAART. However, an increase in the non-HIV immunocompromised population, noncompliance with current treatment...

  15. 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.

  16. Current Concept of Geometrical Accuracy

    OpenAIRE

    Görög Augustín; Görögová Ingrid

    2014-01-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the fiel...

  17. 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

  18. Classification of Simple Current Invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1991-01-01

    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.)

  19. Management of insomnia: current trends

    OpenAIRE

    Rimple Jeet Kaur; Sneha R. Ambwani; Bharati Mehta

    2014-01-01

    Insomnia is one of the most commonly occurring sleep disorders worldwide. With increased prevalence of insomnia the demand of the people seeking pharmacological treatment for this disease is continuously increasing. Numerous options are currently available for its treatment and with our increased understanding of the neurophysiological factors involved in the insomnia continuous research is being conducted to seek newer pharmacological treatments. Recent advancement in treatment of insomnia i...

  20. Biofield Science: Current Physics Perspectives

    OpenAIRE

    Kafatos, Menas C.; Chevalier, Gaétan; Chopra, Deepak; Hubacher, John; Kak, Subhash; Theise, Neil D.

    2015-01-01

    This article briefly reviews the biofield hypothesis and its scientific literature. Evidence for the existence of the biofield now exists, and current theoretical foundations are now being developed. A review of the biofield and related topics from the perspective of physical science is needed to identify a common body of knowledge and evaluate possible underlying principles of origin of the biofield. The properties of such a field could be based on electromagnetic fields, coherent states, bi...

  1. Overlimiting current in a microchannel

    OpenAIRE

    Dydek, E. Victoria; Zaltzman, Boris; Rubinstein, Isaak; Deng, D. S.; Mani, Ali; Bazant, Martin Z.

    2011-01-01

    We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged side walls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for over-limiting current in a microchannel: (i) {\\it surface conduction} carried by excess counterions, which dominates for very thin channels, (ii) convection by {\\it electro-osmotic flow} on the side walls, which dominates for thicker channels and tran...

  2. Current and constituent quark masses

    International Nuclear Information System (INIS)

    It is shown how the current quark mass, engendered by the electroweak sector, gives rise to a constituent quark mass, via the Dyson-Schwinger equations. The chiral symmetry breaking phenomenon on massless QCD is thereby seen to have an implementable generalization to the situation in which the strong bare mass is non-zero. A consistent renormalization is carried out for an arbitrary covariant gauge. (author). 16 refs

  3. Current uses of ophthalmic lasers.

    OpenAIRE

    O'Neill, D; GREGSON, R; McHugh, D

    1992-01-01

    Current laser treatments are quick, relatively painless, and well tolerated. Some ophthalmic techniques can be performed only by laser while others have a lower morbidity than alternative treatments. Peripheral retinal photocoagulation and focal photocoagulation now offer greatly improved visual prognosis for diabetic patients with proliferative diabetic retinopathy or diabetic macular disease. Selected cases of macular degeneration may be treated by focal laser photocoagulation. The role of ...

  4. Current trends of banking innovations

    OpenAIRE

    A.M. Karminskiy; O.R. Zhdanova

    2013-01-01

    The current stage of the global banking system development takes place in an increasingly competitive environment and unstable financial markets. One of the key factors of bank's successful development is a policy of continuous innovative behavior. Nowadays innovation is a key factor of bankingnstability, competitiveness and sustainable growth.The aim of the article. The main goal of this article is to examine key trends of banking innovations and innovative in Russia. Experience in the devel...

  5. Current practice for pulmonary hypertension

    Institute of Scientific and Technical Information of China (English)

    Toru Satoh

    2014-01-01

    Objective To investigate the current practice of pulmonary hypertension including current epidemiology,diagnosis and treatment.Data sources The review was based on data obtained from the published articles and guidelines.Study selection Articles with high level of evidence or current best evidence in each issue were selected to be reviewed.Results Overall prevalence of pulmonary hypertension was 0.3% to 6% with left heart disease occupying the most proportion,followed by pulmonary disease,pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.In diagnosis,a flow diagram of diagnosis of pulmonary hypertension,differential diagnosis of pulmonary hypertension and how to determine the severity of pulmonary hypertension are explained including recent development of magnetic resonance imaging and gene abnormality study on bone morphogenetic protein receptor Ⅱ.In treatment,newlydeveloped pulmonary vasodilators and the way to use them are shown to treat pulmonary hypertension.Conclusion Safer and more effective treatment algorithm and basic researches and clinical trials are warranted to be explored.

  6. Reconnection in thin current sheets

    Science.gov (United States)

    Tenerani, Anna; Velli, Marco; Pucci, Fulvia; Rappazzo, A. F.

    2016-05-01

    It has been widely believed that reconnection is the underlying mechanism of many explosive processes observed both in nature and laboratory, but the question of reconnection speed and initial trigger have remained mysterious. How is fast magnetic energy release triggered in high Lundquist (S) and Reynolds (R) number plasmas?It has been shown that a tearing mode instability can grow on an ideal timescale, i.e., independent from the the Lundquist number, once the current sheet thickness becomes thin enough, or rather the inverse aspect ratio a/L reaches a scale a/L~S-1/3. As such, the latter provides a natural, critical threshold for current sheets that can be formed in nature before they disrupt in a few Alfvén time units. Here we discuss the transition to fast reconnection extended to simple viscous and kinetic models and we propose a possible scenario for the transition to explosive reconnection in high-Lundquist number plasmas, that we support with fully nonlinear numerical MHD simulations of a collapsing current sheet.

  7. 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

  8. 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

  9. Multivariate fluctuation relations for currents

    International Nuclear Information System (INIS)

    This paper is devoted to multivariate fluctuation relations for all the currents flowing across an open system in contact with several reservoirs at different temperatures and chemical potentials, or driven by time-independent external mechanical forces. After some transient behavior, the open system is supposed to reach a nonequilibrium steady state that is controlled by the thermodynamic and mechanical forces, called the affinities. The time-reversal symmetry of the underlying Hamiltonian dynamics implies symmetry relations among the statistical properties of the fluctuating currents, depending on the values of the affinities. These multivariate fluctuation relations are not only compatible with the second law of thermodynamics, but they also imply remarkable relations between the linear or nonlinear response coefficients and the cumulants of the fluctuating currents. These relations include the Onsager and Casimir reciprocity relations, as well as their generalizations beyond linear response. Methods to deduce multivariate fluctuation relations are presented for classical, stochastic and quantum systems. In this way, multivariate fluctuation relations are obtained for energy or particle transport in the effusion of an ideal gas, heat transport in Hamiltonian systems coupled by Langevin stochastic forces to heat reservoirs, driven Brownian motion of an electrically charged particle subjected to an external magnetic field, and quantum electron transport in multi-terminal mesoscopic circuits where the link to the scattering approach is established. (paper)

  10. 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

  11. Current Topics in Epilepsy Surgery.

    Science.gov (United States)

    Usui, Naotaka

    2016-05-15

    This article reviews the current topics in the field of epilepsy surgery. Each type of epilepsy is associated with a different set of questions and goals. In mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS), postoperative seizure outcome is satisfactory. A recent meta-analysis revealed superior seizure outcome after anterior temporal lobectomy compared with selective amygdalohippocampectomy; in terms of cognitive outcome; however, amygdalohippocampectomy may be beneficial. In temporal lobe epilepsy with normal magnetic resonance imaging (MRI), postoperative seizure outcome is not as favorable as it is in MTLE with HS; further improvement of seizure outcome in these cases is necessary. Focal cortical dysplasia is the most common substrate in intractable neocortical epilepsy, especially in children, as well as in MRI-invisible neocortical epilepsy. Postoperative seizure-free outcome is approximately 60-70%; further diagnostic and therapeutic improvement is required. Regarding diagnostic methodology, an important topic currently under discussion is wideband electroencephalogram (EEG) analysis. Although high-frequency oscillations and ictal direct current shifts are considered important markers of epileptogenic zones, the clinical significance of these findings should be clarified further. Regarding alternatives to surgery, neuromodulation therapy can be an option for patients who are not amenable to resective surgery. In addition to vagus nerve stimulation, intracranial stimulation such as responsive neurostimulation or anterior thalamic stimulation is reported to have a modest seizure suppression effect. Postoperative management such as rehabilitation and antiepileptic drug (AED) management is important. It has been reported that postoperative rehabilitation improves postoperative employment status. Pre- and post-operative comprehensive care is mandatory for postoperative improvement of quality of life. PMID:26984452

  12. Current topics in radiation measurements

    International Nuclear Information System (INIS)

    Current research topics in radiation measurements will be shown in this presentation. Applications of radiation measurements have grown with the development of radiation sources and new measurement techniques. Recent new developments in this field are briefly introduced. Optical techniques such as lasers and fiber optics, which are widely used in an optical communication field, are successfully applied to radiation measurements. Micro-fabrication techniques and the photolithography technique are indispensable for semiconductor or even gas detectors. Complicated analog signal processing is being simplified by the use of fast computation techniques available in digital chips. Cryogenic X-ray detectors are making a great progress in the energy resolution. Some of the current research topics found in the recent journals and international symposiums are as follows: the development of room temperature semiconductor radiation detectors like CdZnTe and SiC, new signal processing methods such as coplanar grid unipolar charge sensing, medical γ-ray imaging, the development of cryogenic X-ray detectors such as STJs (Superconducting Tunnel Junction) and TES (Transition Edge Sensor) microcalorimeters, micromachined gas proportional counters like MSGC/MGC/GEM, new detection system which requires both the energy and spatial resolutions, the search of longer wavelength scintillators, development of new fast scintillators such as LSO/YAP/LuAP, new digital waveform processing based on fast digitizing technique, etc. Current developments are especially focused on the increase of the information derived from the detector and the improvement in the resolution. One of the other directions of the development is toward the microscopic visualization of the radiation. Such an approach must solve many technological difficulties both in fabrication of the detectors and even in the detection scheme, however, we might proceed to open a new phase of radiation measurements soon. (author)

  13. 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

  14. Detection of neutral current events

    International Nuclear Information System (INIS)

    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.)

  15. Nerve lesioning with direct current

    Science.gov (United States)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  16. Transient eddy current flow metering

    CERN Document Server

    Forbriger, Jan

    2015-01-01

    Measuring local velocities or entire flow rates in liquid metals or semiconductor melts is a notorious problem in many industrial applications, including metal casting and silicon crystal growth. We present a new variant of an old technique which relies on the continuous tracking of a flow-advected transient eddy current that is induced by a pulsed external magnetic field. This calibration-free method is validated by applying it to the velocity of a spinning disk made of aluminum. First tests at a rig with a flow of liquid GaInSn are also presented.

  17. Eddy currents and corner singularities

    OpenAIRE

    Buret, François; Dauge, Monique; Dular, Patrick; Krähenbühl, Laurent; Péron, Victor; Perrussel, Ronan; Poignard, Clair; Voyer, Damien

    2011-01-01

    Eddy current problems are addressed in this paper, in a bidimensional setting where the conducting medium is non-magnetic and has a corner singularity. For any fixed skin depth we show that the flux density is bounded near the corner, unlike the perfect conducting case. Then as the skin depth goes to zero, the first two terms of a multiscale expansion of the magnetic potential are introduced to tackle the magneto-harmonic problem. The heuristics of the method are given and numerical computati...

  18. 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.

  19. 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

  20. Deep brain stimulation: Current status

    Directory of Open Access Journals (Sweden)

    Sanjay Pandey

    2015-01-01

    Full Text Available In the last two decades, applications of deep brain stimulation (DBS have expanded rapidly in the field of neurosciences. The most common indications for DBS are Parkinson′s disease, medically refractory seizures, essential tremors, and primary dystonia. This device has also been used as an investigational tool in patients having Tourette′s syndrome, tardive dyskinesia, and refractory seizures. In the field of psychiatry, DBS has been used for the treatment of refractory obsessive compulsive disorder and depression. The complications are mainly related to surgery, the device, and its stimulation. This article provides an overview of the current status and recent advances in the field of DBS.

  1. DESY: Handling persistent eddy currents

    International Nuclear Information System (INIS)

    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

  2. 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

  3. Electric Current Circuits in Astrophysics

    CERN Document Server

    Kuijpers, Jan; Fletcher, Lyndsay

    2014-01-01

    Cosmic magnetic structures have in common that they are anchored in a dynamo, that an external driver converts kinetic energy into internal magnetic energy, that this magnetic energy is transported as Poynting flux across the magnetically dominated structure, and that the magnetic energy is released in the form of particle acceleration, heating, bulk motion, MHD waves, and radiation. The investigation of the electric current system is particularly illuminating as to the course of events and the physics involved. We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial magnetic storms.

  4. Overlimiting current in a microchannel

    CERN Document Server

    Dydek, E Victoria; Rubinstein, Isaak; Deng, D S; Mani, Ali; Bazant, Martin Z

    2011-01-01

    We revisit the classical problem of diffusion-limited ion transport to a membrane (or electrode) by considering the effects of charged side walls. Using simple mathematical models and numerical simulations, we identify three basic mechanisms for over-limiting current in a microchannel: (i) {\\it surface conduction} carried by excess counterions, which dominates for very thin channels, (ii) convection by {\\it electro-osmotic flow} on the side walls, which dominates for thicker channels and transitions to (iii) {\\it electro-osmotic instability} on the membrane end in very thick channels. These intriguing electrokinetic phenomena may find applications in biological separations, water desalination, and electrochemical energy storage.

  5. Short, high current electrodynamic tether

    OpenAIRE

    Savich, N.A.; Sanmartín Losada, Juan Ramón

    1994-01-01

    An electrodynamic tether experiment, to be carried out in the Russian spacecraft Almaz, is proposed. A 10 km tether would be deployed downwards; the lower 8 km would be nonconductive, the upper 2 km would be conductive, bare, and 2.2 mm in diameter, and would act as a thruster, with power supply at the top. This hybrid arrangement allows for other, onelectrodynamic experiments,reducing costs; it also limits the induced electromotive force, reducing the power to be handled. The current-volt...

  6. Xerostomia: current streams of investigation.

    Science.gov (United States)

    Quock, Ryan L

    2016-07-01

    Xerostomia is the subjective feeling of dry mouth, and it is often related to salivary hypofunction. Besides medication-related salivary hypofunction, Sjögren syndrome and head-and-neck radiation are two common etiologies that have garnered considerable attention. Approaches to treating and/or preventing salivary hypofunction in patients with these conditions will likely incorporate gene therapy, stem cell therapy, and tissue engineering. Advances in these disciplines are central to current research in the cure for xerostomia and will be key to eventual treatment. PMID:27189896

  7. Current Science: Some early history

    OpenAIRE

    Krishnan, Riki; Balaram, P.

    2007-01-01

    1932, the year in which Current Science was born, saw the world in the midst of transition. Europe, then the centre of science had the First World War well behind it and was purposefully heading towards the Second War. The demand for selfgovernance and independence in India was rapidly zaining ground. The major revolution in atomic physics had already reached its high point. C. V. Raman had announced the discovery of the ‘Raman effect’ in 1928 and had been recognized with the Nobel Prize, in ...

  8. 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

  9. Sinoprobe Datacenter Development: Current Status

    Science.gov (United States)

    Guan, Y.; Dong, S.; Chen, Z.; Chen, G.; Cheng, M.

    2011-12-01

    The project of the Sinoprobe datacenter development is to build new IT infrastructures needed to store, visualize and manage all the data acquired by SinoProbe program.The SinoProbe data center is designed using service-oriented architecture (SOA) principles. More specifically, service component architecture (SCA) is used to implement sinoprobe data services. It also uses various advanced technologies such as Java/JEE for the platform, PostgresSQL/PostGIS for the data storage, ApacheDS for LDAP, CoachDB for the medadata storage, GeoServer for the GIS services, ExtJs and OpenLayer for the Ajax framework, and Apache Shiro for the security framework. Through the integration and development of various technologies used, the major services of the datacenter system are implemented including the security infrastructure services (user authentication and authorization), metadata services, data warehouse stores, data services, GIS services, and web portal. There are also visualization components including the development of a virtual globe to replace the currently used Google Earth. This poster presents the current status of the SinoProbe data center development, and the detailed discussion of the system.

  10. Current puzzles in nuclear physics

    International Nuclear Information System (INIS)

    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 28Si(α,α')28Si 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.)

  11. 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. PMID:24589819

  12. 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.

  13. Geomagnetically induced currents in Europe

    Directory of Open Access Journals (Sweden)

    Viljanen Ari

    2014-03-01

    Full Text Available Statistics of geomagnetically induced currents (GIC in the European high-voltage power grids based on 1-min geomagnetic recordings in 1996–2008 and on 1-D models of the ground conductivity have been derived in the EURISGIC project (European Risk from Geomagnetically Induced Currents. The simplified yet realistic power grid model indicates that large GIC can occur anywhere in Europe. However, geomagnetic variations are clearly larger in North Europe, so it is the likely region of significant GIC events. Additionally, there are areas in the North with especially low ground conductivities, which further tend to increase GIC. The largest modelled GIC values at single substations in 1996–2008 are about 400 A in the Nordic Countries, about 100 A in the British Isles, about 80 A in the Baltic Countries, and less than 50 A in Central and South Europe. The largest GIC event in the period studied is the Halloween storm on 29–30 October 2003, and the next largest ones occurred on 15 July 2000 and 9 November 2004.

  14. Gravity currents at Ormen Lange

    Energy Technology Data Exchange (ETDEWEB)

    Vikeboe, Frode; Berntsen, Jarle; Furnes, Gunnar

    2001-12-01

    Time series of temperature and velocities at Ormen Lange, located in the Storegga region off mid-Norway, indicate that close to the seabed, at depths ranging from 500-1000 m, large temperature fluctuations are accompanied by short peak values in speed. The extreme events are driven by strong pressure gradients, due to strong atmospheric low pressures and/or internal pressure fronts between warmer Atlantic Water (AW) and colder Norwegian Sea Water (NSW). Along the shelf slope at OL we may get steepening of the iso surfaces of density, separating AW and NSW, due to strong Ekman veering during storms or approaching internal density fronts. During such events the density surfaces tend to undershoot their equilibrium level, and as the forcing weakens, the suppressed water may run up along the shelf slope. In this run up phase, peak values in the velocities are often found. As a result of the run up phase, heavy water may be elevated onto the shelf. Subsequently dense fluid will spread under the influence of forces produced by its own buoyancy and motions of this form are often referred to as gravity currents. They are characterised by the distinctive nature of the front, which consists of a raised head leading a shallower flow behind. The shape of the head and body of the gravity current, along with velocity, depend on a range of parameters. This report investigates the velocities that may occur with parameters of relevance for Ormen Lange. (author)

  15. Radar-eddy current GPR

    Directory of Open Access Journals (Sweden)

    A. O. Abramovych

    2014-06-01

    Full Text Available Introduction. At present there are many electrical schematic metal detectors (the most common kind of ground penetrating radar, which are differ in purpose. Each scheme has its own advantages and disadvantages compared to other schemes. Designing metal detector problem of optimal selection of functional units most schemes can only work with a narrow range of special purpose units. Functional units used in circuits can be replaced by better ones, but specialization schemes do not provide such a possibility. Description of problem. Author has created a "complex for research of functional units of metal detectors" that is the universal system that meets the task. With this set of studies conducted on the practical implementation of radar-eddy current method of distinguishing non-ferrous metals (gold, copper, etc. is based. Description of method. Mathematical tools using have to be treated as a signal metal detector to distinguish metals: gold, copper and others. Conclusions. Processing of partial pulses may have information about beforehand signal loss during propagation in heterogeneous media with lossy nonuniform distribution parameters. Using eddy currents To calculate the value of the input voltage depending on the conductivity of the metal in the receiving antenna.Combining two different methods for processing the received signal theoretically it could be proved that with high probability can distinguish non-ferrous metals - gold, copper etc.

  16. Current conveyors variants, applications and hardware implementations

    CERN Document Server

    Senani, Raj; Singh, A K

    2015-01-01

    This book serves as a single-source reference to Current Conveyors and their use in modern Analog Circuit Design. The authors describe the various types of current conveyors discovered over the past 45 years, details of all currently available, off-the-shelf integrated circuit current conveyors, and implementations of current conveyors using other, off-the-shelf IC building blocks. Coverage includes prominent bipolar/CMOS/Bi-CMOS architectures of current conveyors, as well as all varieties of starting from third generation current conveyors to universal current conveyors, their implementations and applications. •Describes all commercially available off-the-shelf IC current conveyors, as well as hardware implementations of current conveyors using other off-the-shelf ICs; • Describes numerous variants of current conveyors evolved over the past forty five years; • Describes a number of Bipolar/CMOS/Bi-CMOS architectures of current conveyors, along with their characteristic features; • Includes a comprehe...

  17. 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

  18. Current Developments in Cognitive Linguistics

    Institute of Scientific and Technical Information of China (English)

    Dirk Geeraerts

    2008-01-01

    After 30 years of theoretical development, we need to address the question whether the internal evolution of Cognitive Linguistics can be synthesized: what are the fundamental underlying trends in Cognitive Linguistics, and how do they shape the current developments within Cognitive Linguistics? This paper argues that Cognitive Linguistics is essentially characterized by a gradual recontextualization of the grammar. First, the development of 20th century grammar is characterized by a succession of a decontextualizing and a recontextualizing movement. Second, the various stages in the development of Cognitive Linguistics involve the gradual recovery of the various types of context that were discarded by generative grammar. These involve the experiential and embodied context of meaning in natural Language, the pragmatic context of actual language usage, and the social and cultural context of language as a shared code.

  19. Urban contamination - The current situation

    International Nuclear Information System (INIS)

    Of the nuclides which might be released in a serious accident at a nuclear power plant, radiocaesium would be expected to present the most serious long-term radiological hazard in an urban environment. Deposited radiocaesium has been shown to have a marked and long-lasting affinity for some urban surfaces and forced decontamination is a necessary component of nuclear accident contingency planning. Natural weathering provides only slow and limited decontamination. Decontamination tests with conventional surface cleaning methods and an ion exchange system have met with some success. Present studies are aimed at identification of both the physical and chemical forms of the airborne caesium and elucidating the mechanism by which it becomes attached to urban surfaces. The importance and behaviour of street dust as a potential carrier of contaminant radiocaesium is also under investigation. An appraisal of current knowledge of removing contaminant radiocaesium from the urban environment is presented and some possible lines of research are described

  20. HIGH CURRENT COAXIAL PHOTOMULTIPLIER TUBE

    Science.gov (United States)

    Glass, N.W.

    1960-01-19

    A medium-gain photomultiplier tube having high current output, fast rise- time, and matched output impedance was developed. The photomultiplier tube comprises an elongated cylindrical envelope, a cylindrical anode supported at the axis of the envelope, a plurality of elongated spaced opaque areas on the envelope, and a plurality of light admitting windows. A photo-cathode is supported adjacent to each of the windows, and a plurality of secondary emissive dynodes are arranged in two types of radial arrays which are alternately positioned to fill the annular space between the anode and the envelope. The dynodes are in an array being radially staggered with respect to the dynodes in the adjacent array, the dynodes each having a portion arranged at an angle with respect to the electron path, such that electrons emitted by each cathode undergo multiplication upon impingement on a dynode and redirected flight to the next adjacent dynode.

  1. Current trends in plant breeding

    International Nuclear Information System (INIS)

    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)

  2. Limitations of bootstrap current models

    International Nuclear Information System (INIS)

    We assess the accuracy and limitations of two analytic models of the tokamak bootstrap current: (1) the well-known Sauter model (1999 Phys. Plasmas 6 2834, 2002 Phys. Plasmas 9 5140) and (2) a recent modification of the Sauter model by Koh et al (2012 Phys. Plasmas 19 072505). For this study, we use simulations from the first-principles kinetic code NEO as the baseline to which the models are compared. Tests are performed using both theoretical parameter scans as well as core-to-edge scans of real DIII-D and NSTX plasma profiles. The effects of extreme aspect ratio, large impurity fraction, energetic particles, and high collisionality are studied. In particular, the error in neglecting cross-species collisional coupling—an approximation inherent to both analytic models—is quantified. Furthermore, the implications of the corrections from kinetic NEO simulations on MHD equilibrium reconstructions is studied via integrated modeling with kinetic EFIT. (paper)

  3. 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.

  4. Current trends in radiation protection

    International Nuclear Information System (INIS)

    Organizers of the 11. IRPA International Congress have wished to take advantage of this occasion to launch a new series of books dedicated to review the current important problems of concerns in radioprotection. The four editors have combined their efforts to assemble within this book contributions from the worldwide and most famous specialists in their respective fields. Their signatures lead to the insurance of a first class information. all aspects of radioprotection are treated, through synthetic articles accessible to all. Very didactic, this book will be useful to radioprotection professionals willing to take the stake of all aspects within their profession, but also to engineers, physicists, physicians, researchers, and non-specialist people who will find here a thorough synthesis of all aspects of radiological protection. (author)

  5. Engineered barriers: current status 1989

    International Nuclear Information System (INIS)

    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 137Cs), 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)

  6. Current puzzles and future possibilities

    International Nuclear Information System (INIS)

    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

  7. Rotating concave eddy current probe

    Science.gov (United States)

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  8. 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.

  9. Current Overview of Pyoderma Gangrenosum

    Directory of Open Access Journals (Sweden)

    Suzan Demir Pektas

    2016-01-01

    Full Text Available Pyoderma gangrenosum (PG, which belongs to neutrophilic dermatosis group, is a rarely seen chronic inflammatory disease. Inhalf of the cases it occurs as a manifestation of an underlying disease. The diagnosis depends on the medical history of the underlying disease, typical clinical presentation, histopathological confirmation and exclusion of the other possible diagnoses. The pathophysiology of PG is not clear, as well as the diagnostic criteria. Although it is more commonly seen in middle-aged and women, the exact prevalence of the disease is unknown. No golden standard treatment modality has been defined. Intense immunosuppressive therapy is needed in order to prevent the disease progression which can lead to severe morbidity and can heal with cribriform scars. The difficulties in the diagnosis, the importance of the early diagnosis, and its severe morbidities encouraged us to emphasize PG and review it in the light of the current literature.

  10. Biofield Science: Current Physics Perspectives.

    Science.gov (United States)

    Kafatos, Menas C; Chevalier, Gaétan; Chopra, Deepak; Hubacher, John; Kak, Subhash; Theise, Neil D

    2015-11-01

    This article briefly reviews the biofield hypothesis and its scientific literature. Evidence for the existence of the biofield now exists, and current theoretical foundations are now being developed. A review of the biofield and related topics from the perspective of physical science is needed to identify a common body of knowledge and evaluate possible underlying principles of origin of the biofield. The properties of such a field could be based on electromagnetic fields, coherent states, biophotons, quantum and quantum-like processes, and ultimately the quantum vacuum. Given this evidence, we intend to inquire and discuss how the existence of the biofield challenges reductionist approaches and presents its own challenges regarding the origin and source of the biofield, the specific evidence for its existence, its relation to biology, and last but not least, how it may inform an integrated understanding of consciousness and the living universe. PMID:26665039

  11. Familial Mediterranean fever: current perspectives

    Science.gov (United States)

    Sönmez, Hafize Emine; Batu, Ezgi Deniz; Özen, Seza

    2016-01-01

    Familial Mediterranean fever (FMF) is the most frequent monogenic autoinflammatory disease, and it is characterized by recurrent attacks of fever and polyserositis. The disease is associated with mutations in the MEFV gene encoding pyrin, which causes exaggerated inflammatory response through uncontrolled production of interleukin 1. The major long-term complication of FMF is amyloidosis. Colchicine remains the principle therapy, and the aim of treatment is to prevent acute attacks and the consequences of chronic inflammation. With the evolution in the concepts about the etiopathogenesis and genetics of the disease, we have understood that FMF is more complicated than an ordinary autosomal recessive monogenic disorder. Recently, recommendation sets have been generated for interpretation of genetic testing and genetic diagnosis of FMF. Here, we have reviewed the current perspectives in FMF in light of recent recommendations. PMID:27051312

  12. Market update and current trends

    International Nuclear Information System (INIS)

    In this article BTM Consult (Denmark) gives some insight into what the next five years might hold for wind power on the international scene. Based on the situation as in stands today we see steady growth form 1995's 1,200-1,300 MW per year rate, increasing to 2000 MW annually by the year 2000. This prediction is made on the one hand despite significant growth fluctuations in several major current markets; on the other hand, greater growth in some areas should help balance out the equation to make the 1,200 MW per year - increasing to 2,000 MW per year by 2000 - a fairly reliable prediction. Another indicator of continuing development is the restructuring of some wind companies in order to meet the increasing competition on the international market and to begin cultivation of future wind markets. (au)

  13. The OPERA experiment: current status

    International Nuclear Information System (INIS)

    Full text: The neutrino flavour oscillations hypothesis has been confirmed by several experiments, all are based on the observation of the disappearance of a given neutrino flavour. The long baseline neutrino experiment OPERA (Oscillation Project with Emulsion tRacking Apparatus) aims to give the first direct proof of the tau neutrino appearance in a pure muon neutrino beam (CERN neutrinos to Gran Sasso beam). The neutrino interactions in the detector are recorded by Emulsion Cloud Chambers (ECC), stacks of 57 nuclear emulsions interleaved with 1 mm thick lead plates. In 2008 the OPERA experiment has started full data taking in the CNGS beam and around 1700 interactions in the detector have been recorded. After a description of the experiment and the data taking procedure, a review of the current status and preliminary results from 2008 run will be presented. (author)

  14. Current Ideas about Prebiological Compartmentalization

    Directory of Open Access Journals (Sweden)

    Pierre-Alain Monnard

    2015-04-01

    Full Text Available Contemporary biological cells are highly sophisticated dynamic compartment systems which separate an internal volume from the external medium through a boundary, which controls, in complex ways, the exchange of matter and energy between the cell’s interior and the environment. Since such compartmentalization is a fundamental principle of all forms of life, scenarios have been elaborated about the emergence of prebiological compartments on early Earth, in particular about their likely structural characteristics and dynamic features. Chemical systems that consist of potentially prebiological compartments and chemical reaction networks have been designed to model pre-cellular systems. These systems are often referred to as “protocells”. Past and current protocell model systems are presented and compared. Since the prebiotic formation of cell-like compartments is directly linked to the prebiotic availability of compartment building blocks, a few aspects on the likely chemical inventory on the early Earth are also summarized.

  15. 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

  16. Current treatments for radiation retinopathy

    International Nuclear Information System (INIS)

    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

  17. Anomalies in PT-Symmetric Quantum Field Theory

    OpenAIRE

    Milton, Kimball A.

    2003-01-01

    It is shown that a version of PT-symmetric electrodynamics based on an axial-vector current coupling massless fermions to the photon possesses anomalies and so is rendered nonrenormalizable. An alternative theory is proposed based on the conventional vector current constructed from massive Dirac fields, but in which the PT transformation properties of electromagnetic fields are reversed. Such a theory seems to possess many attractive features.

  18. Archaeometry: changes and current trends

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    2007-06-01

    Full Text Available This paper looks through the definition of the term Archaeometry and its different meanings since the first use of the term in the1950s to the present. It is also concerned with the historical background of Archaeometry, its evolution throughout recent decades and the fields currently covered by this new area of knowledge, which must be understood within the limits of archaeology. In addition, a bibliometric analysis has served to show in depth the trends of archaeometric studies and to assess their role in current archaeological research. Finally, some ideas on the particular knowledge generated by Archaeometry as well as its future and immediate perspectives are also discussed.  

    Este trabajo realiza un recorrido por la definición del término Arqueometría y las distintas acepciones que ha ido teniendo desde su aparición en la década de los 50 del siglo pasado hasta el presente. También se profundiza en los antecedentes históricos, en la evolución acaecida en las últimas décadas y en los campos de actuación cubiertos en la actualidad por esta nueva área de conocimiento, cuyo desarrollo no puede entenderse al margen de la propia arqueología. Un análisis bibliométrico ha servido además para conocer en profundidad las tendencias en este tipo de estudios arqueométricos y valorar el papel que juegan en la investigación arqueológica actual. Por último, se discuten algunas ideas sobre las particulares características del conocimiento generado por la Arqueometría, así como su futuro y perspectivas más inmediatas.

  19. Current trends of banking innovations

    Directory of Open Access Journals (Sweden)

    A.M. Karminskiy

    2013-06-01

    Full Text Available The current stage of the global banking system development takes place in an increasingly competitive environment and unstable financial markets. One of the key factors of bank's successful development is a policy of continuous innovative behavior. Nowadays innovation is a key factor of bankingnstability, competitiveness and sustainable growth.The aim of the article. The main goal of this article is to examine key trends of banking innovations and innovative in Russia. Experience in the development of new banking products, services and technologies in the Russian market is mainly based on international practice. Noteworthy is the fact that Russian banks take over not only the successful practice of new product lines, but also information technology as well as key methodological aspects of bank management and the technological aspects related the business processes.The results of the analysis. Innovative policy in the credit institution must not take place spontaneously. The positive effect of innovation can be achieved only if there is the possibility of managing the innovation process, which is not possible without a clearly highlighted definition and characteristics of banking innovation, which at least would allow distinguishing of innovation and modification. The paper describes the main aspects of the morphology of banking innovation with the detailed classification depended on the variety of attributes from its origin to the direction of action and highlights the major trends of current banking innovation, such as:development of information and cyber technology (and hence the possibility of the emergence of computational complexity and risk prediction models, the development of information security tools,etc.;implementation of customer-oriented model as the best practice;optimization of its own business processes.The article shows a number of real examples of each kind of banking innovation including the innovations in the non

  20. Current status of zirconia restoration.

    Science.gov (United States)

    Miyazaki, Takashi; Nakamura, Takashi; Matsumura, Hideo; Ban, Seiji; Kobayashi, Taira

    2013-10-01

    During the past decade, zirconia-based ceramics have been successfully introduced into the clinic to fabricate fixed dental prostheses (FDPs), along with a dental computer-aided/computer-aided manufacturing (CAD/CAM) system. In this article (1) development of dental ceramics, (2) the current status of dental CAD/CAM systems, (3) CAD/CAM and zirconia restoration, (4) bond between zirconia and veneering ceramics, (5) bond of zirconia with resin-based luting agents, (6) surface finish of zirconia restoration and antagonist enamel wear, and (7) clinical evaluation of zirconia restoration are reviewed. Yttria partially stabilized tetragonal zirconia polycrystalline (Y-TZP) showed better mechanical properties and superior resistance to fracture than other conventional dental ceramics. Furthermore, ceria-stabilized tetragonal zirconia polycrystalline and alumina nanocomposites (Ce-TZP/A) had the highest fracture toughness and had resistance to low-temperature aging degradation. Both zirconia-based ceramics have been clinically available as an alternative to the metal framework for fixed dental prostheses (FDPs). Marginal adaptation of zirconia-based FDPs is acceptable for clinical application. The most frequent clinical complication with zirconia-based FDPs was chipping of the veneering porcelain that was affected by many factors. The mechanism for the bonding between zirconia and veneering ceramics remains unknown. There was no clear evidence of chemical bonding and the bond strength between zirconia and porcelain was lower than that between metal and porcelain. There were two alternatives proposed that might avoid chipping of veneering porcelains. One was hybrid-structured FDPs comprising CAD/CAM-fabricated porcelain parts adhering to a CAD/CAM fabricated zirconia framework. Another option was full-contour zirconia FDPs using high translucent zirconia. Combined application of silica coating and/or silane coupler, and 10-methacryloyloxydecyl dihydrogen phosphate is

  1. 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

  2. Aktuelles Vaterschaftsrecht Current Paternity Law

    Directory of Open Access Journals (Sweden)

    Silvia C. Groppler

    2004-07-01

    Full Text Available Das Fachbuch enthält eine sehr vollständige Übersicht über die Entwicklung und die derzeitige rechtliche Situation im Bereich der Vaterschaftsfeststellung und -anfechtung. Das Buch ist in erster Linie für Praktiker/-innen geschrieben, also insbesondere für Familienrichter/-innen, Jugend- und Standesämter sowie für Anwälte und Anwältinnen, die auf dem Gebiet des Vaterschaftsrechts tätig sind. Es ist aber auch geeignet für all diejenigen, die juristisch mit Vaterschaftsproblemen zu tun haben und sich einen fundierten Überblick verschaffen wollen bzw. das Buch als Nachschlagewerk zu einzelnen Problemfeldern des Vaterschaftsrechts nutzen wollen.This specialized book contains a complete overview of the development and current legal situation in the area of the determination and contestation of paternity. The book is primarily written for practitioners, especially for family judges, youth and registry offices, as well as for male and female lawyers who work in the field of paternity law. But it is also suitable for those who deal with legal paternity problems and would like to gain a sound overview, i.e. would like to use the book as a reference work for specific problem areas of paternity law.

  3. Current trends in ion implantation

    International Nuclear Information System (INIS)

    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.)

  4. Flux focusing eddy current probe

    Science.gov (United States)

    Simpson, John W. (Inventor); Clendenin, C. Gerald (Inventor); Fulton, James P. (Inventor); Wincheski, Russell A. (Inventor); Todhunter, Ronald G. (Inventor); Namkung, Min (Inventor); Nath, Shridhar C. (Inventor)

    1997-01-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks and material loss in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil. The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. The maximum sensor output is obtained when positioned symmetrically above the crack. Hence, by obtaining the position of the maximum sensor output, it is possible to track the fault and locate the area surrounding its tip. The accuracy of tip location is enhanced by two unique features of the sensor; a very high signal-to-noise ratio of the probe's output which results in an extremely smooth signal peak across the fault, and a rapidly decaying sensor output outside a small area surrounding the crack tip which enables the region for searching to be clearly defined. Under low frequency operation, material thinning due to corrosion damage causes an incomplete shielding of the pick-up coil. The low frequency output voltage of the probe is therefore a direct indicator of the thickness of the test sample.

  5. REACH and nanomaterials: current status

    International Nuclear Information System (INIS)

    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.

  6. Osteoporosis: Current concepts and controversies

    International Nuclear Information System (INIS)

    The recent attention given to osteoporosis by the media has been focused on informing women of the ''silent epidemic'' that results in an insidious loss of bone mass primarily evident through crush fractures of the vertebrae, and fractures of the wrist and hip. Public consciousness of this disorder has also been heightened by the toll in health care dollars, measuring approximately $6 billion annually. In the past decade, major advances have been made in understanding the pathophysiology of postmenopausal bone loss and in prevention and treatment of involutional osteoporosis. In more recent years, considerable effort has been expended in the development of methods for quantitatively assessing the skeleton so that osteoporosis can be detected early, its progression and response to therapy carefully monitored, and its risk effectively ascertained. There is not yet, however, a consensus on which method or methods, if any, are most efficacious for diagnosing and monitoring the individual patient or for extensive screening of large populations. The purpose of this refresher course is to review current concepts and controversies in regard to the epidemiology, pathophysiology, diagnosis and management of osteoporosis. Particular emphasis is given to the issues of noninvasive bone mineral measurement and the utility of screening procedures

  7. Nanodosimetry: Principle and Current Status

    Science.gov (United States)

    Schulte, Reinhard W.

    2011-05-01

    Due to the success of theoretical track structure Monte Carlo simulations, showing that features of ionization patterns on the nanometer level are important for the biological effectiveness of ionizing radiation, several new methods for experimental track structure investigations have been developed in recent years. These methods all use the principle of density scaling in low-pressure gas to probe track structure in macroscopic dimensions, ideally with single-ionization resolution. The new field of experimental track structure investigation, which has been called nanodosimetry, can be approached in two ways: (1) the number of ionizations in a defined, ideally wall-less, sensitive volume is registered per single primary particle and cluster size distributions are obtained, or (2) the full track structure of an ion track segment is "imaged". Existing nanodosimetric methods are based on the first approach, but a track structure imaging detector is currently under development at Loma Linda University. This contribution will review the principle and existing technical approaches to nanodosimetry and will give an outlook on future developments and applications.

  8. Nanodosimetry: Principle and Current Status

    International Nuclear Information System (INIS)

    Due to the success of theoretical track structure Monte Carlo simulations, showing that features of ionization patterns on the nanometer level are important for the biological effectiveness of ionizing radiation, several new methods for experimental track structure investigations have been developed in recent years. These methods all use the principle of density scaling in low-pressure gas to probe track structure in macroscopic dimensions, ideally with single-ionization resolution. The new field of experimental track structure investigation, which has been called nanodosimetry, can be approached in two ways: (1) the number of ionizations in a defined, ideally wall-less, sensitive volume is registered per single primary particle and cluster size distributions are obtained, or (2) the full track structure of an ion track segment is 'imaged'. Existing nanodosimetric methods are based on the first approach, but a track structure imaging detector is currently under development at Loma Linda University. This contribution will review the principle and existing technical approaches to nanodosimetry and will give an outlook on future developments and applications.

  9. Current status of converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasialasie, H.; Holappa, L.

    1995-12-31

    This literature work is mainly focusing on the mechanisms of modern converter steelmaking and related with the evaluation of converter technology applied during the last decades and further to the future. The history of steelmaking has been briefly reviewed from bloomeries and early-steelmaking processes to the progress of modern converter process. The pneumatic converter processes were developed in the 1850`s and thereafter the basis for the rapid growth of steel industries was established for the next 100 years. The world production of steel has not continuously grown but fluctuating quite much. It reached 723 Mt in 1994. The production is believed to grow the forecast for the year 2003 being approximately 800 Mt. Electric arc furnace production is estimated to reach 280 Mt by 2003, and BOFIOH will reach 520 Mt by 2003. The current status of the converter steelmaking process is briefly described both on its theoretical bases and practical technological progresses. Developments which significantly improve the process are briefly discussed. Several more recent developments such as combined oxygen blowing process, increased scrap melting, post combustion and hot metal pretreatment are discussed. The future progress will be in further development of these process characteristics as well as in eventual emerging of the continuous converter process. (author)

  10. Current scenario of malaria vaccine

    Directory of Open Access Journals (Sweden)

    Jarnail Singh Braich

    2012-04-01

    Full Text Available Malaria is one of the deadliest infectious diseases that affects millions of people worldwide including India. As an addition to chemoprophylaxis and other antimalarial interventions malaria vaccine is under extensive research since decades. The vaccine development is more difficult to predict than drug development and presents a unique challenge as already there has been no vaccine effective against a parasite. Effective malaria vaccine could help eliminate and eradicate malaria; there are currently 63 vaccine candidates, 41 in preclinical and clinical stages of development. Vaccines are being designed to target pre-erythrocytic stages, erythrocytic stage or the sexual stages of Plasmodium taken up by a feeding mosquito, or the multiple stages. Two vaccines in preclinical and clinical development target P. falciparum; and the most advanced candidate is the pre-erythrocytic vaccine RTS,S which is in phase-III clinical trials. It is likely that world's first malaria vaccine will be available by 2015 at the country level. More efficacious second generation malaria vaccines are on the way to development. Safety, efficacy, cost and provision of the vaccine to all communities are major concerns in malaria vaccine issue. [Int J Basic Clin Pharmacol 2012; 1(2.000: 60-66

  11. Current developments in personnel monitoring

    International Nuclear Information System (INIS)

    Personnel monitoring is being carried out using devices which range from conventional passive dosimeters like the film badge and the TLD, to sophisticated Electronic Personal Dosimeters (EPD) for integrated gamma, beta and neutron dose measurement. In the passive category, OSL dosimeters are posing a serious challenge to TLD dosimeters with their advantages over TLD such as superiority in lower detection limits, comparatively simpler readout unit with optical stimulation, re-readability, etc. The latest evolution of Electronic Personal Dosimeters (EPD) has reached a technical level fulfilling the requirements of the IEC and ANSI standards for approval as legal or official dosimeter. There are a number of serious contenders to the conventional Si semiconductor diode detectors. The MOSFET dosimeter, direct ion storage dosimeter and the CCD dosimeter are some of the promising alternatives. The neutron personal dosimeters are based on measuring a physical or (bio) chemical effect with properties similar to the deposition of dose equivalent in tissue, measuring LET spectra and folding them over the quality factor, or designing a device with an energy dependence of the response resembling the fluence-to-dose equivalent conversion coefficient. Most neutron EPDs, virtually all commercial ones, are based on the last method. The paper discusses the current developments and future trends in the area of personnel monitoring instruments and devices. (author)

  12. Current ethical issues in IVF.

    Science.gov (United States)

    Grobstein, C; Flower, M

    1985-12-01

    This article has briefly reviewed the range of public policy issues and ethical questions raised with respect to IVF. It then discussed selected issues that are now under policy debate and decision. Given the wide acceptance of IVF as a medical procedure for married couples, what variants might also be ethically defensible? IVF for unmarried couples appears defensible under specific conditions that are equally applicable to married couples. Involvement of third parties (gamete donation and gestational surrogacy) is more complex and needs case by case examination. Sperm donation appears to generate little that is ethically new when coupled with IVF but requires the same care and concern as AID. Egg or embryo donation, however, does raise new ethical questions that need close attention and continuing analysis. Freezing of human embryos also breaks new ethical ground, particularly in the options it generates beyond a narrowly defined medical domain. Certain of these options are better not undertaken without further public policy decision. Improvement of current procedures and techniques through effective clinical trials can be ethically carried out in terms of scientific and medical perspectives. However, efforts in this direction will be more effective if undertaken within a public policy framework that clearly defines acceptability during a transitional period of confidence-building. PMID:3833444

  13. Current Direct Neutrino Mass Experiments

    CERN Document Server

    Drexlin, G; Mertens, S; Weinheimer, C

    2013-01-01

    In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

  14. Management of insomnia: current trends

    Directory of Open Access Journals (Sweden)

    Rimple Jeet Kaur

    2014-04-01

    Full Text Available Insomnia is one of the most commonly occurring sleep disorders worldwide. With increased prevalence of insomnia the demand of the people seeking pharmacological treatment for this disease is continuously increasing. Numerous options are currently available for its treatment and with our increased understanding of the neurophysiological factors involved in the insomnia continuous research is being conducted to seek newer pharmacological treatments. Recent advancement in treatment of insomnia is the introduction of non-benzodiazepine hypnotic medications such as zaleplon, zolpidem, and eszopiclone. Ramelteon, a melatonin agonist, is also helpful for sleep initiation diffi culties. Tri-cyclic antidepressants have long been used for insomnia but use has been limited by unwanted anticholinergic side-effects. A hypocretin/orexin antagonist MK-4035 is presently in clinical trials. Serotonin antagonists and inverse agonists are being investigated for their usefulness in insomnia; newer research examining other mechanisms of action suggest that agents which modulate the histaminergic, serotonergic, melontonergic, and hypocretin/orexin and perhaps gamma-aminobutyric acid B systems could play a promising role in management of insomnia. [Int J Basic Clin Pharmacol 2014; 3(2.000: 272-276

  15. Eddy-current probe design

    International Nuclear Information System (INIS)

    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

  16. Malaria vaccine: a current perspective

    Directory of Open Access Journals (Sweden)

    Shobhona Sharma

    2008-02-01

    Full Text Available The observation that inactivated Plasmodium sporozoites could protect against malaria is about a hundred years old. However, systematic demonstration of protection using irradiated sporozoites occurred in the nineteen-sixties, providing the impetus for the development of a malaria vaccine. In 1983, the circumsporozoite protein (CSP, a major sporozoite surface antigen, became the first Plasmodium gene to be cloned, and a CSP-based vaccine appeared imminent. Today, 25 years later, we are still without an effective malaria vaccine, despite considerable information regarding the genomics and proteomics of the malaria parasites. Although clinical immunity to malaria has been well-documented in adults living in malaria endemic areas, our understanding of the host-immune responses operating in such malaria immune persons remains poor, and limits the development of immune control of the disease. Currently, several antigen and adjuvant combinations have entered clinical trials, in which efficacy against experimental sporozoite challenge and/or exposure to natural infection is evaluated. This review collates information on the recent status of the field. Unresolved challenges facing the development of a malaria vaccine are also discussed.

  17. Cranial MRI: Current clinical applications

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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. PMID:26929531

  20. [Current topics in pediatric nutrition].

    Science.gov (United States)

    Morali, A; Vidailhet, M

    2002-07-01

    As main current topics in pediatric nutrition we have considered the results of the continuing research on the long term consequences of fetal malnutrition and intra-uterine growth retardation with the concept of metabolic imprinting leading to chronic disease in adulthood, the progresses of knowledge in the fields of iron metabolism and regulatory mechanisms of satiety, hunger and energetic balance, a better determination of recommended docosahexanoic and arachidonic acids intake in the first months of life for premature and term infants, and the studies on probiotics and prebiotics utilization for preventive and curative purposes. The concerns about vitamin D insufficiency in France have markedly decreased with the generalization ten years ago of cholecalciferol supplementation of infant formula, and more recently the authorization of dairy products supplementation. On the contrary the problem of iron deficiency in young children remains, as well as two major nutritional concerns: the very low percentage of breast-fed infants and the dramatic increase of childhood obesity which affects presently 14% of 10 year old children versus 5% in 1980. PMID:12162162

  1. Test of SU(3) Symmetry in Hyperon Semileptonic Decays

    CERN Document Server

    Pham, T N

    2013-01-01

    Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann Okubo(GMO) baryon mass formula which is satisfied to a few percents and provides evidence for SU(3) symmetry breaking in the divergence of the vector current matrix element. In this paper, we shall present a similar GMO relation for the hyperon semileptonic decay axial vector form factors. Using these relations and the measured axial vector current to vector current form factor ratios, we show that SU(3) symmetry breaking in hyperon semileptonic decays is of 5-11%.

  2. Test of SU(3) Symmetry in Hyperon Semileptonic Decays

    CERN Document Server

    Pham, T N

    2014-01-01

    Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann--Okubo (GMO) baryon mass formula which is satisfied to a few percents, showing evidence for a small SU(3) symmetry breaking effect in the GMO mass formula. In this talk, I would like to present a similar GMO relation obtained in a recent work for hyperon semileptonic decay axial vector current matrix elements. Using these generalized GMO relations for the measured axial vector current to vector current form factor ratios, it is shown that SU(3) symmetry breaking in hyperon semileptonic decays is of $5-11%$ and confirms the validity of the Cabibbo model for hyperon semi-leptonic decays.

  3. Parity violation in quasielastic electron-nucleus scattering within the relativistic impulse approximation

    CERN Document Server

    González-Jiménez, R; Donnelly, T W

    2015-01-01

    We study parity violation in quasielastic (QE) electron-nucleus scattering using the relativistic impulse approximation. Different fully relativistic approaches have been considered to estimate the effects associated with the final-state interactions. We have computed the parity-violating quasielastic (PVQE) asymmetry and have analyzed its sensitivity to the different ingredients that enter in the description of the reaction mechanism: final-state interactions, nucleon off-shellness effects, current gauge ambiguities. Particular attention has been paid to the description of the weak neutral current form factors. The PVQE asymmetry is proven to be an excellent observable when the goal is to get precise information on the axial-vector sector of the weak neutral current. Specifically, from measurements of the asymmetry at backward scattering angles good knowledge of the radiative corrections entering in the isovector axial-vector sector can be gained. Finally, scaling properties shown by the interference $\\gamma...

  4. Defining and resolving current systems in geospace

    Science.gov (United States)

    Ganushkina, N. Y.; Liemohn, M. W.; Dubyagin, S.; Daglis, I. A.; Dandouras, I.; De Zeeuw, D. L.; Ebihara, Y.; Ilie, R.; Katus, R.; Kubyshkina, M.; Milan, S. E.; Ohtani, S.; Ostgaard, N.; Reistad, J. P.; Tenfjord, P.; Toffoletto, F.; Zaharia, S.; Amariutei, O.

    2015-11-01

    Electric currents flowing through near-Earth space (R ≤ 12 RE) can support a highly distorted magnetic field topology, changing particle drift paths and therefore having a nonlinear feedback on the currents themselves. A number of current systems exist in the magnetosphere, most commonly defined as (1) the dayside magnetopause Chapman-Ferraro currents, (2) the Birkeland field-aligned currents with high-latitude "region 1" and lower-latitude "region 2" currents connected to the partial ring current, (3) the magnetotail currents, and (4) the symmetric ring current. In the near-Earth nightside region, however, several of these current systems flow in close proximity to each other. Moreover, the existence of other temporal current systems, such as the substorm current wedge or "banana" current, has been reported. It is very difficult to identify a local measurement as belonging to a specific system. Such identification is important, however, because how the current closes and how these loops change in space and time governs the magnetic topology of the magnetosphere and therefore controls the physical processes of geospace. Furthermore, many methods exist for identifying the regions of near-Earth space carrying each type of current. This study presents a robust collection of these definitions of current systems in geospace, particularly in the near-Earth nightside magnetosphere, as viewed from a variety of observational and computational analysis techniques. The influence of definitional choice on the resulting interpretation of physical processes governing geospace dynamics is presented and discussed.

  5. Persistent current in a magnetized Rashba ring

    Institute of Scientific and Technical Information of China (English)

    Zhang Lin; Wang Jun

    2011-01-01

    We theoretically study the persistent currents flowing in a Rashba quantum ring subjected to the Rashba spinorbit interaction.By introducing uniform or nonuniform magnetization into the ring,we find that a nonzero persistent charge current circulates in the ring,which stems from the original equilibrium spin current due to the Rashba spinorbit interaction.Because of broken time reversal symmetry,the two oppositely flowing spin-up and spin-down charge currents of the equilibrium spin current are no longer equal,and so a net persistent charge current can flow in the system.It is also found that the persistent current can be modulated by the Fermi energy,the Rashba spin-orbit interaction strength and the magnetization in the ring.Moreover,the magnetization perpendicular to the ring plane can optimize the current.The persistent current flowing in the ring is a manifestation of the nonzero equilibrium spin current existing in the ring.

  6. RF current drive components in a tokamak

    International Nuclear Information System (INIS)

    Theoretical analysis of low frequency current drive in a tokamak is presented. The global model discussed includes kinetic hot plasma effects and collisions. It is found that all kinds of wave-plasma interactions (resonant wave-electron interaction, resonant wave-ion interaction and collisions) can contribute to the current drive. The analysis presented stresses the two new current drive components, the resonant helicity current and the nonresonant collisionless current. Helicity current drive is proportional to the parallel helicity flux and to the wave damping strength, which is defined by the wave-plasma interaction process. The collisionless part of the nonresonant current is proportional to wave damping on ions. However, this is an electron current, and wave-ion interaction just creates necessary polarization of the wave to drive a current. The resistive MHD limit is considered as well, and the correct expression for the RF driven current including the Alfven resonance effect, is given. (author) 17 refs

  7. Current status of diuretic renography

    International Nuclear Information System (INIS)

    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

  8. 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(®). PMID:26355220

  9. Current directions in radiopharmaceutical research

    International Nuclear Information System (INIS)

    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)

  10. Current therapy of hilar cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Stephanie HiuYan Lau; WanYee Lau

    2012-01-01

    BACKGROUND: Hilar cholangiocarcinoma (HC) is an adeno-carcinoma of the extrahepatic biliary tree arising from the main left or right hepatic ducts or their confluence. This tumor is still considered to be difficult to treat or to cure. DATA SOURCES: We reviewed the medical literature on HC. Relevant and updated information on this tumor was analyzed in a concise and easy-to-read manner. The article is not intended to be a systematic review, but an extensive search was conducted on PubMed and MEDLINE using the keywords "hilar cholangiocarcinoma" and "Klatskin tumor" until July 2011. RESULTS: The selection and the timing of management options for patients with HC are determined by the degree of certainty of the diagnosis, the general condition of the patients, the underlying liver function and the stage of the disease. Current treatment of HC can be divided into curative and palliative treatment. For the curative treatment, local excision should only be used on small tumors which are confined to the bile duct wall and Bismuth I papillary carcinoma. Partial hepatectomy should be combined with caudate lobe resection and porta-hepatis lymph node dissection. The results of these major resections can be improved with portal vein embolization, and staging laparoscopy and laparoscopic ultrasound. The role of preoperative biliary drainage is controversial. Autotransplantation for HC gave disappointing results while the Mayo Protocol of chemoradiation for selecting patients with unresectable HC for orthotopic liver transplantation has been widely accepted. Palliative treatment included bypass surgery, endoscopic or percutaneous stenting, photodynamic therapy, intraluminal brachytherapy, and external radiation and systemic therapy. CONCLUSIONS: Adequate surgery with R0 resection should be the main goal of treatment. For patients with unresectable HC, treatment aims to improve the quality and quantity of their survival.

  11. [Current status of autism studies].

    Science.gov (United States)

    Kurita, H

    2001-01-01

    The current status of autism studies was reviewed based on English articles published during the 1990s. Although the concepts of autism and pervasive developmental disorders (PDD) are established, diagnostic criteria of PDDNOS or atypical autism, which is frequently difficult to differentiate from autism, need to be established. The prevalence of autism has been estimated as about 0.05% in the U.S and many European countries, while it was reported to be 0.1% or higher in Japan and some European countries, though the reasons for this difference are unclear. High-functioning (IQ > or = 70) autism may not be as rare a condition as previously thought and both its difference from and similarity to Asperger's syndrome, the highest functioning PDD subtype, need clarification. About 20 to 40% of children with autism lose meaningful words by the age of 2 years and display autistic symptoms thereafter. Such autism, called the setback type in Japan, has been demonstrated to have a poorer adolescent/adult outcome compared to autism without setback and its relationship with childhood disintegrative disorder, which displays a clearer regression after normal development for at least the first 2 years of life, needs to be addressed. The etiology of autism is now considered mostly genetic for reasons, such as the significantly higher concordance rate of autism in identical twin pairs (60-80%) than in fraternal twin pairs (0-10%) and an 3-5% incidence of autism among sibs of an autism proband, 30 to 100 times higher than that in the general population. The involvement of several genes is implicated to create susceptibility for autism, yet the responsible genes have not been identified. Although there is no medication to cure autism, some psychotropic drugs, such as antipsychotics and SSRIs, seem effective for behavior problems in autism patients. Psychosocial treatments are the main therapeutic approach to autism, though they are yet to be well systematized. It is important to

  12. 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

  13. The current interruption process in vacuum analysis of the currents and voltages of current-zero measurements

    OpenAIRE

    van Lanen, E.P.A.

    2008-01-01

    The circuit breaker helps protecting vulnerable equipment in a power network from hazardous short-circuit currents by isolating a fault, when it occurs. They perform this task by extinguishing a plasma arc that appears as soon as the breaker's contacts separate, and through which the short-circuit current flows. In an AC network, the current's value runs periodically through zero, and each current zero provides the breaker with an opportunity to quench the arc, because here, its energy input ...

  14. Current trends in breast reduction.

    Science.gov (United States)

    Roje, Zdravko; Roje, Zeljka; Milosević, Milan; Varvodić, Josip; Mance, Marko

    2012-06-01

    Results of our study describe the long term effects of reduction mammaplasty. Many women with excessively small or large breasts have an altered personal self-image and often suffer from low self-esteem and other psychological stresses. This procedure is designed to reduce and reshape large breasts, and since the size, shape, and symmetry of a woman's breasts can have a profound effect on her mental and physical well-being it is important to observe the patient's long-term outcome. Currently, breast reduction surgery is safe, effective and beneficial to the patient. In Croatia, reduction mammoplasty is often excluded from the general health care plan. The distinction between "reconstructive" versus "cosmetic" breast surgery is very well defined by the American Society of Plastic Surgeons Board of Directors. Unfortunately, the Croatian Health Society has yet to standardize such a distinction. There is an imperative need for evidence-based selection criteria. We retrospectively analyzed data of 59 female patients suffering from symptomatic macromastia who underwent reduction mammaplasty over a 16 year period (1995 until 2011). Our aim was to compare and contrast the various techniques available for reduction mammaplasty and to determine, based on patient outcome and satisfaction, which technique is most suited for each patient. The results of our study generally reinforce the observation that reduction mammaplasty significantly provides improvements in health status, long-term quality of life, postsurgical breast appearance and significantly decrease physical symptoms of pain. A number of 59 consecutive cases were initially treated with the four different breast reduction techniques: inverted-T scat or Wisa pattern breast reduction, vertical reduction mammaplasty, simplified vertical reduction mammaplasty, inferior pedicle and free nipple graft techniques. The average clinical follow-up period was 6-months, and included 48 patients. The statistical analysis of the

  15. Current management strategies for hypercalcemia.

    Science.gov (United States)

    Pecherstorfer, Martin; Brenner, Karin; Zojer, Niklas

    2003-01-01

    The two most common causes of hypercalcemia are primary hyperparathyroidism and neoplastic disease. Parathyroidectomy is the only curative intervention for the former condition. In the rare cases of patients with primary hyperparathyroidism who present with clinical symptoms due to their hypercalcemia, pharmacological treatment may be required. Fluid repletion and intravenous (IV) administration of bisphosphonates are recommended in the literature. Calcium receptor agonists (calcimimetic agents) are at the present time only available for use within clinical trials. Cancer patients usually present with symptoms of hypercalcemia. Rapid institution of antihypercalcemic treatment is essential in preventing life-threatening deterioration. Fluid repletion and administration of bisphosphonates are the treatment mainstays in hypercalcemia of malignancy. Five bisphosphonates are currently licensed in Europe for treatment of tumor-associated hypercalcemia: etidronate, clodronate, pamidronate, ibandronate, and zoledronate. In the US, pamidronate and zoledronate are licensed for use in this indication. Bisphosphonates containing nitrogen atoms (e.g. pamidronate, ibandronate, and zoledronate) are more potent than those without (e.g. etidronate, clodronate, and tiludronate). In patients with malignant hypercalcemia, the efficacy of the individual bisphosphonate depends on dose administered and initial serum calcium concentration. At present, pamidronate has been studied in the greatest number of investigations and in the largest number of patients. In the literature, the efficacy of pamidronate in restoring normocalcemia ranges between 40% and 100%, depending on the dose used and baseline serum calcium concentration. More recently, one study reported that pamidronate was inferior to zoledronate. In this study, the duration of response was also longer in the two zoledronate groups (30 and 40 days) than in the pamidronate group (17 days). The most serious adverse events of

  16. 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.

  17. Quasielastic production of polarized hyperons in antineutrino--nucleon reactions

    CERN Document Server

    Akbar, F; Athar, M Sajjad; Singh, S K

    2016-01-01

    We have studied the longitudinal and perpendicular polarizations of final hyperon($\\Lambda$,$\\Sigma$) produced in the antineutrino induced quasielastic charged current reactions on nucleon targets. The nucleon-hyperon transition form factors are determined from the experimental data on quasielastic $(\\Delta S =0)$ charged current (anti)neutrino--nucleon scattering and the semileptonic decay of neutron and hyperons assuming G--invariance, T--invariance and SU(3) symmetry. The vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parameterizations available in literature have been used. A dipole parameterization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of axial vector form factor assuming PCAC and GT relation extended to strangeness sector have been used in numerical evaluations. The flux averaged cross section and polarization observables corresponding to CERN Gargamelle experiment have been calculated...

  18. 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

  19. 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"...

  20. Development of Multichannel Eddy Current Testing Instrument

    International Nuclear Information System (INIS)

    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

  1. Linearized dynamical approach to current algebra

    International Nuclear Information System (INIS)

    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

  2. The Fluid Mechanics of Pyroclastic Density Currents

    Science.gov (United States)

    Dufek, Josef

    2016-01-01

    Pyroclastic density currents are generated in explosive volcanic eruptions when gas and particle mixtures remain denser than the surrounding atmosphere. These mobile currents have a diversity of flow regimes, from energetic granular flows to turbulent suspensions. Given their hazardous nature, much of our understanding of the internal dynamics of these currents has been explored through mathematical and computational models. This review discusses the anatomy of these currents and their phenomenology and places these observations in the context of forces driving the currents. All aspects of the current dynamics are influenced by multiphase interactions, and the study of these currents offers insight into a high-energy end-member of multiphase flow. At low concentration, momentum transfer is dominated by particle-gas drag. At higher concentration, particle collisions, friction, and gas pore pressure act to redistribute momentum. This review examines end-member theoretical models for dilute and concentrated flow and then considers insight gained from multiphase simulations of pyroclastic density currents.

  3. Direct images of semi-meromorphic currents

    OpenAIRE

    Andersson, Mats; Wulcan, Elizabeth

    2014-01-01

    We introduce a calculus for direct images of semi-meromorphic currents. We also provide results on the behaviour of these currents under the action of holomorphic differential operators and interior multiplication by holomorphic vector fields.

  4. Anomalous bootstrap current due to drift waves

    International Nuclear Information System (INIS)

    An anomalous parallel current driven by radial flux in tokamak is discussed. Drift waves, which cause an anomalous cross field diffusion, can generate a parallel current in a sheared magnetic field, if the fluctuation level has radial dependence. (author)

  5. 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.

  6. [Current malaria situation in Turkmenistan].

    Science.gov (United States)

    Amangel'diev, K A

    2001-01-01

    Malaria is one of the main health problems facing most developing countries having a hot climate. It is a problem in Turkmenistan. The country is situated in Central Asia, north of the Kopetdag mountains, between the Caspian Sea to the west and the Amu-Darya river to the east. Turkmenistan stretches for a distance of 1,100 km from west to east and 650 km from north to south. It borders Kazakhstan in the north, Uzbekistan in the east and north-east, Iran in the south, and Afghanistan in the south-east. Seven malaria vector species are found in Turkmenistan, the main ones being Anopheles superpictus, An. pulcherrimus, and An. martinius. The potentially endemic area consists of the floodplains of the Tejen and Murgab rivers, with a long chain of reservoirs built along them. In 1980 most cases of imported malaria were recorded in military personnel who had returned from service in Afghanistan. In the past years, only tertian (Plasmodium vivax) malaria has been recorded and there have been no death from malaria over that period. In the Serkhetabad (Gushgi) district there are currently 5 active foci of malaria infection, with a population of 22,000 people. In 1999, forty nine cases of P. vivax malaria were recorded in Turkmenistan. Of them, 36 cases, including 4 children under 14 years were diagnosed for the first time while 13 were relapses. There were 88 fewer cases than those in the previous year (by a factor of 2.8). There were 17 more cases of imported malaria than those in 1998 (by a factor of 1.7), most of which occurred in the foci of malaria infection (Serkhetabad, Tagtabazar, and Kerki districts), in the city of Ashkhabat and in Lebap, Dashkhovuz and Akhal Regions. The emergence of indigenous malaria in the border areas was due to the importation of the disease at intervals by infected mosquitoes flying in from neighbouring countries (e.g. Afghanistan), the lack of drugs to treat the first cases and the lack of alternative insecticides. Most patients suffer

  7. Constant Current Models of Brushless DC Motor

    OpenAIRE

    Krykowski, Krzysztof; Hetmańczyk, Janusz

    2013-01-01

    Two constant current models of Permanent Magnet Brushless Direct Current Motor (PM BLDC) are presented in the paper. In the first part of the paper principle of operation, basic properties and mathematical equations describing PM BLDC models are given. Then, two different constant current models of PM BLDC motor are considered: In the first model, PM BLDC motor is approximated with dc motor; in the second model, modified constant current model is applied with additional block, which is used t...

  8. Electromagnetic currents induced by color fields

    OpenAIRE

    Tanji, Naoto

    2015-01-01

    The quark production in classical color fields is investigated with a focus on the induction of an electromagnetic current by produced quarks. We show that the color SU(2) and the SU(3) theories lead significantly different results for the electromagnetic current. In uniform SU(2) color fields, the net electromagnetic current is not generated, while in SU(3) color fields the net current is induced depending on the color direction of background fields. Also the numerical study of the quark pro...

  9. Topological Orbital Angular Momentum Hall Current

    OpenAIRE

    Hu, Jiangping

    2005-01-01

    We show that there is a fundamental difference between spin Hall current and orbital angular momentum Hall current in Rashba- Dresselhaus spin orbit coupling systems. The orbital angular momentum Hall current has a pure topological contribution which is originated from the existence of magnetic flux in momentum space while there is no such topological nature for the spin Hall current. Moreover, we show that the orbital Hall conductance is always larger than the spin Hall conductance in the pr...

  10. Neoclassical currents in the Wisconsin Levitated Octupole

    International Nuclear Information System (INIS)

    Neoclassical transport theory predicts the existence of bootstrap current in collisionless plasmas with a significant population of trapped particles. This unidirectional current flows along field lines, and is generated by the balancing of ion-electron friction forces with the viscous forces between trapped and untrapped like particles. The current is driven by gradients in the plasma pressure and temperature. Previous work has identified the existence of bootstrap current in the Wisconsin Levitated Octupole, and this discovery of bootstrap current in the octupole naturally leads to the question of why previous experiments were unsuccessful in their endeavors to identify this current. The original motivation for this thesis was to address that question, by investigating the effects on bootstrap current caused by ohmic currents, plasma fluctuations, and rf fields. Ohmic currents, while naturally present in tokamaks, can be introduced in the octupole, independent of the usual operating procedure, and can be adjusted to be of the same order of magnitude as the expected diamagnetic and parallel currents. The interaction, if any, of bootstrap current and ohmic current can thus be determined without the problem of a large ohmic current masking the neoclassical current. Rf fields can be driven in the octupole plasma with little or no plasma heating. Any anomalous effects on the parallel currents, due to the existence of the rf fields, can then be determined. This thesis consists of four parts: the experimental apparatus and the plasma diagnostics used in these studies; the general theory of neoclassical currents (excluding field errors) and how it is applied to the octupole; the experimental results of this investigation; and a brief discussion of the conclusions that can be inferred from the data

  11. Nuclear electromagnetic currents from chiral EFT

    International Nuclear Information System (INIS)

    Using the method of unitary transformation in combination with chiral effective field theory we derive the pion exchange contributions to the two-nucleon electromagnetic current. A formal definition of the current operator in this scheme and the power counting is presented. We discuss the implications of additional unitary transformations that have to be present to ensure the renormalizability of the one-pion exchange current. Further, we give explicit and compact results for the current in coordinate-space.

  12. 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…

  13. High Precision Current Measurement for Power Converters

    OpenAIRE

    Bastos, M. Cerqueira

    2016-01-01

    The accurate measurement of power converter currents is essential to controlling and delivering stable and repeatable currents to magnets in particle accelerators. This paper reviews the most commonly used devices for the measurement of power converter currents and discusses test and calibration methods.

  14. 49 CFR 236.733 - Current, foreign.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Current, foreign. 236.733 Section 236.733 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, foreign. A term applied to stray electric currents which may affect a signaling system, but...

  15. 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.

  16. Current density imaging during tissue electroporation

    International Nuclear Information System (INIS)

    Delivery of externally applied electric pulses on the target tissue during electroporation increases membrane permeability and induces electric currents in the tissue. To optimize electroporation parameters, the current density and with it associated electric field distributions can be monitored by means of current density imaging (CDI) and magnetic resonance electric impedance tomography (MREIT). (Author)

  17. The spin structure of the Λ hyperon in quenched lattice QCD

    International Nuclear Information System (INIS)

    It has been suggested to use the production of Λ hyperons for investigating the nucleon spin structure. The viability of this idea depends crucially on the spin structure of the Λ. Using nonperturbatively O(a) improved Wilson fermions in the quenched approximation we have studied matrix elements of two-quark operators in the Λ. We present results for the axial vector current, which give us the contributions of the u, d, and s quarks to the Λ spin. (orig.)

  18. New physics upper bound on the branching ratio of B_s --> l+ l-

    CERN Document Server

    Alok, A K; Alok, Ashutosh Kumar

    2005-01-01

    We consider new physics interactions for b --> s l+ l- of the form vector/axial-vector. We derive the upper limit on the branching ratio for the processes B_s --> l+ l-, where l=e or mu, subject to the current experimental bounds on related processes, B --> K l+ l- and B --> K* l+ l-. We obtain 3 sigma upper bounds B(B_s --> e+ e-) mu+ mu-) < 5*10^(-9).

  19. Automated lattice perturbation theory and relativistic heavy quarks in the Columbia formulation

    OpenAIRE

    Lehner, Christoph

    2012-01-01

    We introduce a new computer algebra system optimized for use in lattice perturbation theory as well as continuum perturbation theory and a new framework to perform automated perturbative calculations on top of said computer algebra system. The new framework is used to tune the relativistic heavy quark action in the Columbia formulation at one loop in meanfield-improved perturbation theory. Preliminary results for the matching and O(a)-improvement of heavy-light axial vector currents with ligh...

  20. Eta-Eta' mixing and the derivative of the topological susceptibility at zero momentum transfer

    CERN Document Server

    Nasrallah, N F

    2016-01-01

    The couplings of the isosinglet axial-vector currents to the Eta and Eta' mesons are evaluated in a stable, model independent way by use of polynomial kernels in dispersion integrals. The corrections to the Gell-Mann-Oakes-Renner relation in the isoscalar channel are deduced. The derivative of the topological susceptibility at the origin is calculated taking into account instantons and instanton screening.

  1. Proton Spin from General Colour Symmetry Model

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-Fu; LI Ying-Chuan; WEN Xin-Min

    2001-01-01

    The quark wavefunction in a proton has been calculated by using the global colour symmetry model. We find that the property of this wavefunction is closely related to the nonperturbative vacuum configuration. Using the wavefunction we make the calculation of the matrix element of the axial vector current of the quarks in the proton ground state. Its value is found to be 0.17, which is perfectly consistent with 0.23(+6).

  2. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

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

    2009-01-01

    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...

  3. 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.

  4. EXTRACTION OF INTERNAL TIDE FROM CURRENT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to extract the internal tidal current from the current data which is not measured from the sea surface to the bottom, a data processing method is developed. It is based on the fact that the internal wave currents above and below the sharp thermocline are inverse in direction. This method is a practical extension to that proposed by Shu (1985) that can be only used to quite ideal current data. The ADCP data collected on the South China Sea is then processed by this method. The internal tidal current is successfully extracted.

  5. Real-time plasma current control experiment

    International Nuclear Information System (INIS)

    The plasma current control is useful in plasma confinement studies, because a plasma current gives a great influence to the plasma confinement and stability even in a helical system. For this reason, the real-time plasma current control (RCC) system using a standard personal computer, DOS/V machine, was designed and constructed. The coil currents for the plasma current control were calculated using the standard proportional-integral control algorithm in the digital signal processor and sent to the reflective memory with 100 msec period. Before the 4th experimental campaign, the RCC system was modified to isolate from the present Large Helical Device power supply control system. During the 4th experimental campaign, modified RCC system was used for the real-time feedback control of the plasma current. The plasma was produced and sustained by the Neutral Beam Injection at the magnetic field strength of 1.5 Tesla. The ohmic current was induced by changing the inner vertical coil current that produced the vertical magnetic flux. The plasma current of about 30kA was reduced by the RCC system. This rate was the upper limit of the present coil power supply. The simulation of the plasma current control by ohmic current was carried out using a single filament model. This result shows a good agreement with the experimental result. (author)

  6. The alignment of bootstrap current in tokamak

    International Nuclear Information System (INIS)

    By calculating the trapped particle fraction, solving the Grand-Shafranov equation describing plasma equilibrium, and using Harris model, the magnitude and alignment of the bootstrap current in tokamak are calculated and analysed under the conventional shear regimes and also the negative central shear regimes. The conclusion authors obtained are: through adjusting the profile parameters of plasma density, temperature and current, and the elongation k and triangularity d which describe the plasma shape, the alignment of bootstrap current profile with the equilibrium current profile can be produced; the negative central shear regimes are advantage ous to produce bootstrap current, and the profile of bootstrap current is well-aligned with the equilibrium current profile. By comparing authors' calculated results, the optimized parameters are obtained under the conventional shear and the negative central shear regimes

  7. The universal definition of spin current.

    Science.gov (United States)

    An, Z; Liu, F Q; Lin, Y; Liu, C

    2012-01-01

    The spin current, orbit angular momentum current and total angular momentum current in a tensor form have been universally defined according to the quantum electrodynamics. Their conservation quantities and the continuity equations have been discussed in different cases. Non-relativistic approximation forms are deduced in order to explain their physical meanings, and to analyze some experimental results. The spin current of helical edge states in HgTe/CdTe quantum wells is calculated to demonstrate the properties of the spin current of the two dimensional quantum spin-Hall system. A generalized spin-orbit coupling term in the semiconducting media is deduced based on the theory of the electrodynamics in the moving media. It is recommended to use the effective total angular momentum current instead of the pure spin current to describe the distribution of polarization and the transport properties in spintronics. PMID:22563522

  8. Electric current arising from unpolarized polyvinyl formal

    Indian Academy of Sciences (India)

    P K Khare; P L Jain; R K Pandey

    2000-10-01

    An appreciable electric current is observed in a system consisting of a polyvinyl formal (PVF) film in a sandwich configuration, in the temperature range 30–110°C. The maximum value of the current during first heating is found to be of the order of 10–10 A and its thermograms exhibit one transition (i.e. current peak) at around 60°C. The position of the current peak in thermal spectrum shifts with the heating rate. A temperature dependence of the open circuit voltage is also observed. The activation energy of the process responsible for the current is determined. The magnitude of the current is more in the case of dissimilar electrode systems. It is proposed that the electric current arising from unpolarized metal–polymer–metal system is a water activated phenomenon, which is influenced by the transitional changes of the polymer.

  9. Stray current control in electrolysis plant

    International Nuclear Information System (INIS)

    Stray current can appear in any industrial plant powered by electricity. In electrolysis plants the probability for stray current appearance is high due to the use of electrolytes, which are current-conductive liquid media. Busbars, metallic equipment, electrolyte, the ground and the human body are to a different extent DC current-conductive. Brought in contact in an electrolysis plant, they act as a complex electrical network supplied by a rectifier. As a result, uncontrolled stray currents can flow causing hazard (even electrocution) to the operating personal, power loss and/or damage to the equipment. Despite its major importance for all metal winning and refining electrolysis processes, the stray current issue is very scarcely treated in the published literature. This paper reveals the fundamentals for stray current appearance pointing out to the two major loops in the plant. In the internal loop stray current flows through the electrolyte distribution system causing power loss and hardware damage by stray current induced corrosion. The heat exchanger used for electrolyte preheating is especially critical. The external stray current loop covers stray current cases caused by electrolyte leakage. It impacts on power losses and hazards to the personnel. LUSCURE (LUrgi Stray-CUrrent-cuRE) is a new method for localization, control and reduction of stray current in an electrolysis plant. It involves a translation of the plant and equipment design into an equivalent electrical circuit that is calculated and analysed. LUSCURE was verified by assessing a German copper refinery and by being extensively used in plant and equipment design for the High Current Density Copper Electrowinning Process (HCD). (author)

  10. Discrimination of Inrush Currents from Faults Current in Power Transformers using Gravitational Search Algorithm (GSA)

    OpenAIRE

    Mohamad Kazem Daryabari; Mahmoud Ebadian; Alireza Moradi

    2011-01-01

    The magnetizing inrush current phenomenon is a large transient condition, which occurs when a transformer is energized. The inrush current magnitude may be as high as ten times of transformer rated current that causes mal-operation of protection systems. Indeed, the similarity between signatures of Inrush current and internal fault condition make this failure. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this project, an Artifici...

  11. Hadronization in tau -> K K pi nu_tau decays

    CERN Document Server

    Roig, Pablo

    2008-01-01

    Hadronization in tau -> K K pi nu_tau decays is driven by both vector and axial-vector currents that we study, guided by the following principles: The 1/N_C expansion -worked out at leading order, considering only the contribution of the lightest spin one resonances-, approximate chiral symmetry at low energies and the appropriate asymptotic behaviour we demand to the associated form factors. All these features are implemented in the resonance theory. Most of its couplings are determined by imposing the short-distance requirements of vector and axial-vector spectral functions within QCD. We plan to improve our prediction of the hadronic spectra using recently available experimental data.

  12. Radiative meson decays in a relativistic quark model

    International Nuclear Information System (INIS)

    Motivated by the recent lattice QCD results indicating that the topological charge contribution to the flavor singlet axial vector current can be traded off by the constituent quark masses, we investigate the radiative decays of pseudoscalar (π, K, η, η'), vector (ρ, K*, ω, φ) and axial vector (A1) mesons using a simple relativistic constituent quark model. For both simplicity and relativity, we take advantage of the distinguished features in the light-cone quantization method: (1) the Fock-state expansion of meson wavefunctions are not contaminated by the vacuum fluctuation, (2) the assignment of meson quantum numbers are given by the Melosh transformation. The computed decay widths of ρ, ω → π(η)γ, K* → Kγ, A1 → πγ and the transition form factor of π0 → γ*γ at 0 ≤ Q2 ≤ 8 GeV2 are in a remarkably good agreement with the experimental data. (author)

  13. Absolute geostrophic currents in global tropical oceans

    Science.gov (United States)

    Yang, Lina; Yuan, Dongliang

    2016-03-01

    A set of absolute geostrophic current (AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profiles in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin (except the North Indian Ocean, where the circulation is dominated by monsoons). The identified non-Sverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom (JEBAR) and mesoscale eddy nonlinearity.

  14. Measured currents in JET limiters during disruptions

    International Nuclear Information System (INIS)

    Structures mounted inside a tokamak must be able to withstand the electromagnetic forces which arise during disruptions of the plasma. This paper reports on halo current measurements in the JET tokamak during disruptions. A toroidally distributed array of current sensing tiles reveal that in many disruptions a high degree of toroidal uniformity exists. However in exceptional disruptions the halo current measured at different toroidal positions varies by more than a factor of 2. This latter class of disruption has been observed to result in an asymmetric displacement of the vacuum vessel. The total halo current is estimated to be up to 15% of the initial plasma current. The halo current width for a particular disruption is estimated to be 8 cm

  15. Observable currents in lattice field theories

    CERN Document Server

    Zapata, José A

    2016-01-01

    Observable currents are spacetime local objects that induce physical observables when integrated on an auxiliary codimension one surface. Since the resulting observables are independent of local deformations of the integration surface, the currents themselves carry most of the information about the induced physical observables. I study observable currents in a multisymplectic framework for Lagrangian field theory over discrete spacetime. A weak version of observable currents preserves many of their properties, while inducing a family of observables capable of separating points in the space of physically distinct solutions. A Poisson bracket gives the space of observable currents the structure of a Lie algebra. Peierls bracket for bulk observables gives an algebra homomorphism mapping equivalence classes of bulk observables to weak observable currents. The study covers scalar fields, nonlinear sigma models and gauge theories (including gauge theory formulations of general relativity) on the lattice. Even when ...

  16. Controlling local currents in molecular junctions

    CERN Document Server

    Yadalam, Hari Kumar

    2016-01-01

    The effect of non-equilibrium constraints and dephasing on the circulating currents in molecular junctions are analyzed. Circulating currents are manifestations of quantum effects and can be induced either by externally applied bias or an external magnetic field through the molecular system. In symmetric Aharonov-Bohm ring, bond currents have two contributions, bias driven and magnetic field driven. We analyze the competition between these two contributions and show that, as a consequence, current through one of the branches can be completely suppressed. We then study the effect of asymmetry (as a result of chemical substitution) on the current pathways inside the molecule and study asymmetry induced circulating currents (without magnetic field) by tuning the coupling strength of the substituent (at finite bias).

  17. A review of the quantum current standard

    International Nuclear Information System (INIS)

    The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments. (topical review)

  18. Eddy current analysis in fusion devices

    International Nuclear Information System (INIS)

    In magnetic fusion devices, particularly tokamaks and reversed field pinch (RFP) experiments, time-varying magnetic fields are in intimate contact with electrically conducting components of the device. Induced currents, fields, forces, and torques result. This note reviews the analysis of eddy current effects in the following systems: Interaction of a tokamak plasma with the eddy currents in the first wall, blanket, and shield (FWBS) systems; Eddy currents in a complex but two-dimensional vacuum vessel, as in TFTR, JET, and JT-60; Eddy currents in the FWBS system of a tokamak reactor, such as NET, FER, or ITER; and Eddy currents in a RFP shell. The cited studies are chosen to be illustrative, rather than exhaustive. 42 refs

  19. A review of the quantum current standard

    Science.gov (United States)

    Kaneko, Nobu-Hisa; Nakamura, Shuji; Okazaki, Yuma

    2016-03-01

    The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments.

  20. Current diffusion in rail-gun conductors

    International Nuclear Information System (INIS)

    A method has been developed to analyze one- and two-dimensional, nonlinear current diffusion in rail-gun conductors. A nonlinear current-diffusion equation that accounts for the temperature dependence of electrical conductivity has been developed from Maxwell's equations. A finite-difference heat-transfer computer program was adapted to solve the current-diffusion and thermal-diffusion problems for rail-gun conductors in one and two dimensions. The nonlinear current-diffusion equation was also extended to account for the magnetic-field dependence of the magnetic permeability, thus allowing ferromagnetic materials to be considered. A one-dimensional finite-difference technique was developed for ferromagnetic materials. Two one-dimensional test problems that compare results with other analyses are discussed. A series of calculations of current density and rail temperature was done for various size rectangular rails. One analysis of current diffusion in a ferromagnetic material was also performed

  1. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L;

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...... short-circuit current was analyzed in order to compare the results with the allowable DC current component based in the IEC. Finally the normal operating condition for the power plant was modeled....

  2. Eddy currents in a conducting sphere

    Science.gov (United States)

    Bergman, John; Hestenes, David

    1986-01-01

    This report analyzes the eddy current induced in a solid conducting sphere by a sinusoidal current in a circular loop. Analytical expressions for the eddy currents are derived as a power series in the vectorial displacement of the center of the sphere from the axis of the loop. These are used for first order calculations of the power dissipated in the sphere and the force and torque exerted on the sphere by the electromagnetic field of the loop.

  3. Eddy Current Model of Ball Lightning

    OpenAIRE

    Shelton, J. D.

    2011-01-01

    Eddy Current Model of Ball Lightning Calculations show that high-energy ball lightning may consist of a ball of plasma containing a large circular electric current arising as an eddy current generated by lightning. Synthetic ball lightning might serve as a method of plasma confinement for purposes of nuclear fusion. In this paper, three articles concerning ball lightning and the related phenomenon of large ball lightning are combined to provide insight into this rarely glimpsed occurrence.

  4. Salt taste inhibition by cathodal current

    OpenAIRE

    Hettinger, Thomas P.; Frank, Marion E.

    2009-01-01

    Effects of cathodal current, which draws cations away from the tongue and drives anions toward the tongue, depend on the ionic content of electrolytes through which the current is passed. To address the role of cations and anions in human salt tastes, cathodal currents of −40 to −80 µA were applied to human subjects’ tongues through supra-threshold salt solutions. The salts were sodium chloride, sodium bromide, potassium chloride, ammonium chloride, calcium chloride, sodium nitrate, sodium su...

  5. Computer modelling of superconductive fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.A.; Campbell, A.M.; Coombs, T.A.; Cardwell, D.A.; Storey, R.J. [Cambridge Univ. (United Kingdom). Interdisciplinary Research Centre in Superconductivity (IRC); Hancox, J. [Rolls Royce, Applied Science Division, Derby (United Kingdom)

    1998-05-01

    Investigations are being carried out on the use of superconductors for fault current limiting applications. A number of computer programs are being developed to predict the behavior of different `resistive` fault current limiter designs under a variety of fault conditions. The programs achieve solution by iterative methods based around real measured data rather than theoretical models in order to achieve accuracy at high current densities. (orig.) 5 refs.

  6. Does the Current Account Still Matter?

    OpenAIRE

    Maurice Obstfeld

    2012-01-01

    Do global current account imbalances still matter in a world of deep international financial markets where gross two-way financial flows often dwarf the net flows measured in the current account? Contrary to a complete markets or 'consenting adults' view of the world, large current account imbalances, while very possibly warranted by fundamentals and welcome, can also signal elevated macroeconomic and financial stresses, as was arguably the case in the mid-2000s. Furthermore, the increasingly...

  7. Power threshold for neutral beam current drive

    International Nuclear Information System (INIS)

    For fully noninductive current drive in tokamaks using neutral beams, there is a power and density threshold condition, setting a minimum value for P3/2/n2. If this condition is not met, stationary state cannot occur, and a tokamak discharge will collapse. This is a consequence of the coupling between current and electron temperature, or between current drive efficiency and energy confinement time. 4 figs

  8. Conserved currents of double field theory

    Science.gov (United States)

    Blair, Chris D. A.

    2016-04-01

    We find the conserved current associated to invariance under generalised diffeomorphisms in double field theory. This can be used to define a generalised Komar integral. We comment on its applications to solutions, in particular to the fundamental string/pp-wave. We also discuss the current in the context of Scherk-Schwarz compactifications. We calculate the current for both the original double field theory action, corresponding to the NSNS sector alone, and for the RR sector.

  9. Konstruktion av current conveyors via makromodellering

    OpenAIRE

    Hjalmarsson, Erik

    2004-01-01

    A current conveyor is an active building block that can be used to implement most active and passive components. It differs from the operation amplifier in that it uses current instead of voltage. The current conveyor also has significantly higher voltage gain over a broader frequency range. To simplify the construction of analogue circuits and increase the construction efficiency it is desirable to use a top-down methodology. This means that the whole system is partitioned into a hierarchy ...

  10. Current practice in tailings ponds risk assessment

    OpenAIRE

    Pytel, Witold

    2010-01-01

    Current practice for risk assessment posed by surface tailings/waste storage facilities is presented. This involves current legislation and regulations applied in EU countries and over the world and the basics concerned with tailings impoundments design as well. It was proved that a current activity at the existing tailings impoundment structures is presently confined rather to field measurements, monitoring and surveillance understood as a basic source for a “real time risk assessment”.

  11. Josephson current in parallel SFS junctions

    Science.gov (United States)

    Ioselevich, Pavel; Ostrovsky, Pavel; Fominov, Yakov; Feigelman, Mikhail

    We study a Josephson junction between superconductors connected by two parallel ferromagnetic arms. If the ferromagnets are fully polarised, supercurrent can only flow via Cooper pair splitting between the differently polarised arms. The disorder-average current is suppressed, but mesoscopic fluctuations lead to a significant typical current. We extract the typical current from a current-current correlator. The current is proportional to sin2 α / 2 , where α is the angle between the polarisations of the two arms, revealing the spin dependence of crossed Andreev reflection. Compared to an SNS device of the same geometry, the typical SFS current is small by a factor determined by the properties of the superconducting leads alone. The current is insensitive to the flux threading the area between the ferromagnetic arms of the junction. However, if the ferromagnetic arms are replaced by metal with magnetic impurities, or partially polarised ferromagnets, the Josephson current starts depending on the flux with a period of h / e , i.e. twice the superconducting flux quantum.

  12. Tubular solid oxide fuel cell current collector

    Science.gov (United States)

    Bischoff, Brian L.; Sutton, Theodore G.; Armstrong, Timothy R.

    2010-07-20

    An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

  13. SHORT CIRCUIT CURRENT LIMITER IN AC NETWORK

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Short circuit is a serious fault in power network.Some novelcircuit topologies of current limiter using power electronic technology have been developed,which can limit the fault current to any desired level without much penalty.The operating principle and control strategies of such current limiters are discussed in detail.Simulation and experimental results are given to verify the performance of the current limiter,which can meet the requirements set for locations of bus tie,feeder,as well as the main transformer in the distribution network.

  14. Theory of current-drive in plasmas

    International Nuclear Information System (INIS)

    The continuous operation of a tokamak fusion reactor requires, among other things, a means of providing continuous toroidal current. Such operation is preferred to the conventional pulsed operation, where the plasma current is induced by a time-varying magnetic field. A variety of methods has been proposed to provide continuous current, including methods which utilize particle beams or radio frequency waves in any of several frequency regimes. Currents as large as half a mega-amp have now been produced in the laboratory by such means, and experimentation in these techniques has now involved major tokamak facilities worldwide

  15. Current distribution characteristics of superconducting parallel circuits

    International Nuclear Information System (INIS)

    In order to increase the current carrying capacity of the current path of the superconducting magnet system, the portion of parallel circuits such as insulated multi-strand cables or parallel persistent current switches (PCS) are made. In superconducting parallel circuits of an insulated multi-strand cable or a parallel persistent current switch (PCS), the current distribution during the current sweep, the persistent mode, and the quench process were investigated. In order to measure the current distribution, two methods were used. (1) Each strand was surrounded with a pure iron core with the air gap. In the air gap, a Hall probe was located. The accuracy of this method was deteriorated by the magnetic hysteresis of iron. (2) The Rogowski coil without iron was used for the current measurement of each path in a 4-parallel PCS. As a result, it was shown that the current distribution characteristics of a parallel PCS is very similar to that of an insulated multi-strand cable for the quench process

  16. The bootstrap current and its consequences

    International Nuclear Information System (INIS)

    The physical mechanism behind the bootstrap current is explained, and the consequences are discussed with the emphasis on the two main objectives of fusion plasma, confinement and MHD stability. For a tokamak reactor that is optimized for good confinement and stability, and that has a limited size, the total plasma current exceeds the bootstrap current by a factor of three to five and therefore almost all the plasma current must be driven through other means. Furthermore, the neoclassical tearing mode which is driven by the bootstrap current is expected to be the limiting MHD instability in these reactors. Raising the fraction of the bootstrap current is not expected to be beneficial for confinement and stability expect when broad pressure profiles (internal transport barriers) can be realized. In stellarators several optimizations are possible, either optimizing the current to zero such that it does not destroy the desired topology, and it does not generate any current-driven instabilities, or using the current to generate some of the poloidal field. (author)

  17. Eddy current inspection of graphite fiber components

    Science.gov (United States)

    Workman, G. L.; Bryson, C. C.

    1990-01-01

    The recognition of defects in materials properties still presents a number of problems for nondestructive testing in aerospace systems. This project attempts to utilize current capabilities in eddy current instrumentation, artificial intelligence, and robotics in order to provide insight into defining geometrical aspects of flaws in composite materials which are capable of being evaluated using eddy current inspection techniques. The unique capabilities of E-probes and horseshoe probes for inspecting probes for inspecting graphite fiber materials were evaluated and appear to hold great promise once the technology development matures. The initial results are described of modeling eddy current interactions with certain flaws in graphite fiber samples.

  18. A constant current source for extracellular microiontophoresis.

    Science.gov (United States)

    Walker, T; Dillman, N; Weiss, M L

    1995-12-01

    A sophisticated constant-current source suitable for extracellular microiontophoresis of tract-tracing substances, such as Phaseolus vulgaris leucoagglutinin, Biocytin or Fluoro-Gold, is described. This design uses a flyback switched-mode power supply to generate controllable high-voltage and operational amplifier circuitry to regulate current and provide instrumentation. Design features include a fast rise time, +/- 2000 V supply (stable output in current and voltage monitoring, and separate pumping and holding current settings. Three features of this constant-current source make it especially useful for extracellular microiontophoresis. First, the output voltage monitor permits one to follow changes in the microelectrode resistance during current injection. Second, the voltage-limit (or out-of-compliance) indicator circuitry will sound an alarm when the iontophoretic pump is unable to generate the desired current, such as when the micropipette is blocked. Third, the high-compliance voltage power supply insures up to +/- 20 microA of current through 100 M omega resistance. This device has proven itself to be a reliable constant-current source for extracellular microiontophoresis in the laboratory. PMID:8788057

  19. Charged particle beam current monitoring tutorial

    International Nuclear Information System (INIS)

    A tutorial presentation is made on topics related to the measurement of charged particle beam currents. The fundamental physics of electricity and magnetism pertinent to the problem is reviewed. The physics is presented with a stress on its interpretation from an electrical circuit theory point of view. The operation of devices including video pulse current transformers, direct current transformers, and gigahertz bandwidth wall current style transformers is described. Design examples are given for each of these types of devices. Sensitivity, frequency response, and physical environment are typical parameters which influence the design of these instruments in any particular application. Practical engineering considerations, potential pitfalls, and performance limitations are discussed

  20. Lower hybrid current drive in tokamak plasmas

    International Nuclear Information System (INIS)

    Past ten years progress on Lower Hybrid Current Drive (LHCD) experiments have demonstrated the largest non-inductive current (3.6 MA, JT-60U), the longest current sustainment (2 hours, TRIAM-1M), non-inductive current drive at the highest density (n-bare - 1020m-3, ALCATOR-C) and the highest current drive efficiency (ηCD = 3.5x1019 m-2A/W, JT-60). These results indicate that LHCD is one of the most promising methods to drive non-inductive current in the present tokamak plasmas. This paper presents recent experimental results on LHCD experiments. Basic theories of LH waves, the wave propagation and the current drive are briefly summarized. The main part of this paper describes several important results and their physical pictures on recent LHCD experiments; 1) the experimental set-up, 2) the current drive efficiency, 3) the control of current profile and MHD activities, 4) the global energy confinement, 5) the global power flow, 6) fast electron behavior, 7) interaction between LH waves and thermal/fast ions, 8) combination with other CD method. (author)

  1. Current stabilizer for high-ohmic magnets

    International Nuclear Information System (INIS)

    A semiconductor compensation current stabilizer rated at a current of up to 2.5 A is described. The stabilizer is intended for EPR and NMR spectrometer electromagnets with winding resistance of 50 - 600 Ohm. The regulating element uses the 2T903B transistors, and the control circuit-operational amplifiers, type 140UD1B. The current stability is 1x10-5. The number of power high-voltage transistors is determined by the source power and the dynamic range of current variations

  2. Current generation by the Kinetic Alfven wave

    International Nuclear Information System (INIS)

    The current generated and the efficiency of the shear Kinetic Alfven wave are obtained using a self-consistent quasilinear formulation. Also, the current generation by the monochromatic shear Kinetic Alfven wave introduced by Hasegawa is re-examined taking into account the nonresonant electrons. To obtain the RF current density at the level of the ohmic heating current density in a tokamak, the required external magnetic field is smaller than 0.1% of the DC magnetic field, and the parallel electric field (E2), using the Lausanne-TCA-Tokamak parameters is of the order of 0.01 V cm-1. (author)

  3. Generalized gluon currents and applications in QCD

    CERN Document Server

    Mahlon, G; Dunn, C

    1993-01-01

    We consider the process containing two quark lines and an arbitrary number of gluons in a spinor helicity framework. A current with two off-shell gluons appears in the amplitude. We first study this modified gluon current using recursion relations. The recursion relation for the modified gluon current is solved for the case of like-helicity gluons. We apply the modified gluon current to compute the amplitude for $q \\bar q \\rightarrow q \\bar q gg \\cdots g$ in the like-helicity gluon case.

  4. Interhemispheric Field-Aligned Currents: Simulation Results

    Science.gov (United States)

    Lyatsky, Sonya

    2016-04-01

    We present simulation results of the 3-D magnetosphere-ionosphere current system including the Region 1, Region 2, and interhemispheric (IHC) field-aligned currents flowing between the Northern and Southern conjugate ionospheres in the case of asymmetry in ionospheric conductivities in two hemispheres (observed, for instance, during the summer-winter seasons). We also computed the maps of ionospheric and equivalent ionospheric currents in two hemispheres. The IHCs are an important part of the global 3-D current system in high-latitude ionospheres. These currents are especially significant during summer and winter months. In the winter ionosphere, they may be comparable and even exceed both Region 1 and Region 2 field-aligned currents. An important feature of these interhemispheric currents is that they link together processes in two hemispheres, so that the currents observed in one hemisphere can provide us with information about the currents in the opposite hemisphere. Despite the significant role of these IHCs in the global 3-D current system, they have not been sufficiently studied yet. The main results of our research may be summarized as follows: 1) In winter hemisphere, the IHCs may significantly exceed and be a substitute for the local Region 1 and Region 2 currents; 2) The IHCs may strongly affect the magnitude, location, and direction of the ionospheric and equivalent ionospheric currents (especially in the nightside winter auroral ionosphere). 3) The IHCs in winter hemisphere may be, in fact, an important (and sometimes even major) source of the Westward Auroral Electrojet, observed in both hemispheres during substorm activity. The study of the contribution from the IHCs into the total global 3-D current system allows us to improve the understanding and forecasting of geomagnetic, auroral, and ionospheric disturbances in two hemispheres. The results of our studies of the Interhemispheric currents are presented in papers: (note: for publications my last

  5. Magnetopause current as seen by Cluster

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    2005-03-01

    Full Text Available The four-spacecraft, magnetic field measurements on Cluster can be combined to produce an accurate determination of the electric current in the magnetopause boundary during stable magnetopause crossings. For events that are planar on the scale of the spacecraft configuration, the thickness of the current layer can be accurately estimated from its magnetic profile at each spacecraft and the corresponding boundary crossing times. The latter, give a determination of boundary motion relative to the Cluster array. We use the estimates of all these properties, for a range of spacecraft separation distances, to show, firstly, that the estimate of electric current density is representative even when the spatial scale of the configuration of Cluster spacecraft approaches the thickness of the current layer. Secondly, we show that the estimated current lies in the plane of the boundary and demonstrate this for crossings occurring during large-scale ripples on the magnetopause. Thirdly, we show that the magnitude of the current is accurately represented, averaged over the extent of the current layer, by comparing to the change in the boundary-parallel magnetic field component divided by the estimated current layer thickness. We demonstrate this last point using a range of crossings each having a different thickness and crossing speed, different changes in the magnetic field component and different current densities.

  6. Quaternion form of electromagnetic-current equations

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A. (Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Physics)

    1981-09-26

    In this letter, we attempt to express the electromagnetic current equations without magnetic monopoles in the quaternionic form using a quaternionic conjugate operator instead of quaternion differential operator.

  7. PREONS CURRENTS AND WIRELESS POWER TRANSFER

    Directory of Open Access Journals (Sweden)

    Trunev A. P.

    2013-10-01

    Full Text Available In this article, a model of preons electric currents caused by the motion of preons in the electron shells and nuclear shells is proposed. It is assumed that preons currents may contribute to the conductivity of the material. A closed model of electrodynamics, which describes the diffusion of the vector potential due to the contribution to the conductivity of preons currents, is formulated. An analogy of hydrodynamics and electrodynamics of continuous media with preons currents is considered. A model of the wireless transmission of electricity is proposed

  8. Hybrid Current Lead Design of HTS SMES

    Science.gov (United States)

    Ge, T.; Ren, L.; He, Q.; Jiao, F.; Dong, H.; Jin, T.; Zhou, S.

    In application of Superconducting magnetic energy storage device (SMES), current lead represents a key development component. This paper will focus on parameters and structure design of hybrid high-temperature superconductor (HTS) current lead in a SMES with 100 kJ/100 kW class. Based on the theoretical analysis, finite element simulation (FEA) has been used. It studies the thermal influence of variable cross-sectional area, HTS material and the connection between current lead and cryocooler. Some improvements have been proposed to reduce heat losses. At the end of this paper, a whole procedure about hybrid current lead design is given.

  9. Origin of axial current in scyllac

    International Nuclear Information System (INIS)

    The origin of the axial current observed in Scyllac (a high beta stellarator experiment) is discussed. A shaped coil and/or helical winding produce rotational transform which links magnetic lines of force to the plasma column and the axial current is induced electromagnetically. This phenomenon is inherent in a pulsed high-beta stellarator. The rotational transform produced by the induced axial current is much smaller than that associated with the l = 1, 0 equilibrium fields. The effect of the axial current on the equilibrium and stability of the plasma column is thus small. It is also shown that the magnetic field shear near a plasma surface is very strong

  10. Current-voltage curve of a bipolar membrane at high current density

    NARCIS (Netherlands)

    Aritomi, T.; Boomgaard, van den Th.; Strathmann, H.

    1996-01-01

    The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from outsid

  11. An Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converters

    OpenAIRE

    Run Min; Chen Chen; Xiaodong Zhang; Xuecheng Zou; Qiaoling Tong; Qiao Zhang

    2014-01-01

    In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In t...

  12. Simple current extensions and the permutation orbifold

    International Nuclear Information System (INIS)

    We review extensions by integer spin simple currents in two-dimensional conformal field theories and their application in string theory. In particular, we study the problem of resolving the fixed points of a simple current and apply the formalism to the permutation orbifold.

  13. Recent Advances in Studies of Current Noise

    Science.gov (United States)

    Blanter, Yaroslav M.

    This is a brief review of recent activities in the field of current noise intended for newcomers. We first briefly discuss main properties of shot noise in nanostructures, and then turn to recent developments, concentrating on issues related to experimental progress: non-symmetrized cumulants and quantum noise; counting statistics; super-Poissonian noise; current noise and interferometry

  14. Recent Advances in Studies of Current Noise

    OpenAIRE

    Blanter, Ya. M.

    2005-01-01

    This is a brief review of recent activities in the field of current noise intended for newcomers. We first briefly discuss main properties of shot noise in nanostructures, and then turn to recent developments, concentrating on issues related to experimental progress: non-symmetrized cumulants and quantum noise; counting statistics; super-Poissonian noise; current noise and interferometry.

  15. Passive cyclotron current drive for fusion plasmas

    International Nuclear Information System (INIS)

    The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2nd-kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

  16. A quasilinear formulation of turbulence driven current

    Energy Technology Data Exchange (ETDEWEB)

    McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-15

    Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.

  17. A quasilinear formulation of turbulence driven current

    Science.gov (United States)

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

    2014-02-01

    Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.

  18. DENSITY CURRENTS IN ACTIVATED SLUDGE SECONDARY CLARIFIERS

    Science.gov (United States)

    Density currents form in activated sludge secondary clarifiers because the mixed liquor has a density greater than the treated wastewater in the clarifier. This causes the mixed liquor to plunge to the bottom of the clarifier establishing relatively high velocity currents within ...

  19. Frequency analysis of DC tolerant current transformers

    International Nuclear Information System (INIS)

    This article deals with wide frequency range behaviour of DC tolerant current transformers that are usually used in modern static energy meters. In this application current transformers must comply with European and International Standards in their accuracy and DC tolerance. Therefore, the linear DC tolerant current transformers and double core current transformers are used in this field. More details about the problems of these particular types of transformers can be found in our previous works. Although these transformers are designed mainly for power distribution network frequency (50/60 Hz), it can be interesting to understand their behaviour in wider frequency range. Based on this knowledge the new generations of energy meters with measuring quality of electric energy will be produced. This solution brings better measurement of consumption of nonlinear loads or measurement of non-sinusoidal voltage and current sources such as solar cells or fuel cells. The determination of actual power consumption in such energy meters is done using particular harmonics component of current and voltage. We measured the phase and ratio errors that are the most important parameters of current transformers, to characterize several samples of current transformers of both types

  20. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    on Ohm’s law indicates that the critical length of alternating current (AC) gliding arc discharge columns can be larger than that of a corresponding direct current (DC) gliding arc. This finding is supported by previously published images of AC and DC gliding arcs. Furthermore, the analysis shows...