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Sample records for two-loop effective potential

  1. Two loop effective Kahler potential of (non)-renormalizable supersymmetric models

    International Nuclear Information System (INIS)

    Groot Nibbelink, S.; Nyawelo, T.S.

    2005-10-01

    We perform a supergraph computation of the effective Kahler potential at one and two loops for general four dimensional N=1 supersymmetric theories described by arbitrary Kahler potential, superpotential and gauge kinetic function. We only insist on gauge invariance of the Kahler potential and the superpotential as we heavily rely on its consequences in the quantum theory. However, we do not require gauge invariance for the gauge kinetic functions, so that our results can also be applied to anomalous theories that involve the Green-Schwarz mechanism. We illustrate our two loop results by considering a few simple models: the (non-)renormalizable Wess-Zumino model and Super Quantum Electrodynamics. (author)

  2. Two-loop calculation of the effective potential for the Wess-Zumino model

    International Nuclear Information System (INIS)

    Fogleman, G.; Starkmann, G.D.; Viswanathan, K.S.; Simon Fraser Univ., Burnaby, British Columbia

    1983-01-01

    The effective potential for the supersymmetric Wess-Zumino model is computed off-shell to two loops. A renormalization procedure which preserves positivity of the kinetic terms in the effective action is implemented. Supersymmetry is not broken to this order. (orig.)

  3. Two-loop effective potential for Wess-Zumino model using superfields

    International Nuclear Information System (INIS)

    Santos, R.P. dos; Srivastava, P.P.

    1989-01-01

    For the case of several interacting chiral superfields the propagators for the unconstrained superfield potentials in the 'shifted' theory, where the supersymmetry is explicity broken, are derived in a compact form. They are used to compute the one-loop effective potential in the general case, while a superfield calculation of the renormalized effective potential to two loops for the Wess-Zumino models is performed. (authors) [pt

  4. Dynamical symmetry breaking of λφ4 theory in the two loop effective potential

    International Nuclear Information System (INIS)

    Yang Jifeng; Ruan Jianhong

    2002-01-01

    The two loop effective potential of massless λφ 4 theory is presented in several regularization and renormalization prescriptions and the dynamical symmetry breaking solution is obtained in the strong-coupling situation in several prescriptions except the Coleman-Weinberg prescription. The beta function in the broken phase becomes negative and the UV fixed point turns out to be a strong-coupling one, and its numeric value varies with the renormalization prescriptions, a detail which is different from the asymptotic-free solution in the one loop case. The symmetry-breaking phase is shown to be an entirely strong-coupling phase. The reason for the relevance of the renormalization prescriptions is shown to be due to the nonperturbative nature of the effective potential. We also reanalyze the two loop effective potential by adopting a differential equation approach based on the understanding that all the quantum field theories are ill-defined formulations of the 'low-energy' effective theories of a complete underlying theory. The relevance of the prescriptions of fixing the local ambiguities to physical properties such as symmetry breaking is further emphasized. We also tentatively propose a rescaling insensitivity argument for fixing the quadratic ambiguities. Some detailed properties of the strongly coupled broken phase and related issues are discussed

  5. Two-loop scale-invariant scalar potential and quantum effective operators

    CERN Document Server

    Ghilencea, D.M.

    2016-11-29

    Spontaneous breaking of quantum scale invariance may provide a solution to the hierarchy and cosmological constant problems. In a scale-invariant regularization, we compute the two-loop potential of a higgs-like scalar $\\phi$ in theories in which scale symmetry is broken only spontaneously by the dilaton ($\\sigma$). Its vev $\\langle\\sigma\\rangle$ generates the DR subtraction scale ($\\mu\\sim\\langle\\sigma\\rangle$), which avoids the explicit scale symmetry breaking by traditional regularizations (where $\\mu$=fixed scale). The two-loop potential contains effective operators of non-polynomial nature as well as new corrections, beyond those obtained with explicit breaking ($\\mu$=fixed scale). These operators have the form: $\\phi^6/\\sigma^2$, $\\phi^8/\\sigma^4$, etc, which generate an infinite series of higher dimensional polynomial operators upon expansion about $\\langle\\sigma\\rangle\\gg \\langle\\phi\\rangle$, where such hierarchy is arranged by {\\it one} initial, classical tuning. These operators emerge at the quantum...

  6. Dominant two-loop corrections to the MSSM finite temperature effective potential

    International Nuclear Information System (INIS)

    Espinosa, J.R.

    1996-04-01

    We show that two-loop corrections to the finite temperature effective potential in the MSSM can have a dramatic effect on the strength of the electroweak phase transition, making it more strongly first order. The change in the order parameter v/Tc can be as large as 75% of the one-loop daisy improved result. This effect can be decisive to widen the region in parameter space where erasure of the created baryons by sphaleron processes after the transition is suppressed and hence, where electroweak baryogenesis might be successful. We find an allowed region with tan β< or∼4.5 and a Higgs boson with standard couplings and mass below 80 GeV within the reach of LEP II. (orig.)

  7. Complete two-loop effective potential approximation to the lightest Higgs scalar boson mass in supersymmetry

    International Nuclear Information System (INIS)

    Martin, Stephen P.

    2003-01-01

    I present a method for accurately calculating the pole mass of the lightest Higgs scalar boson in supersymmetric extensions of the standard model, using a mass-independent renormalization scheme. The Higgs scalar self-energies are approximated by supplementing the exact one-loop results with the second derivatives of the complete two-loop effective potential in Landau gauge. I discuss the dependence of this approximation on the choice of renormalization scale, and note the existence of particularly poor choices, which fortunately can be easily identified and avoided. For typical input parameters, the variation in the calculated Higgs boson mass over a wide range of renormalization scales is found to be of the order of a few hundred MeV or less, and is significantly improved over previous approximations

  8. Low-energy effective action in two-dimensional SQED: a two-loop analysis

    Science.gov (United States)

    Samsonov, I. B.

    2017-07-01

    We study two-loop quantum corrections to the low-energy effective actions in N=(2,2) and N=(4,4) SQED on the Coulomb branch. In the latter model, the low-energy effective action is described by a generalized Kähler potential which depends on both chiral and twisted chiral superfields. We demonstrate that this generalized Kähler potential is one-loop exact and corresponds to the N=(4,4) sigma-model with torsion presented by Roček, Schoutens and Sevrin [1]. In the N=(2,2) SQED, the effective Kähler potential is not protected against higher-loop quantum corrections. The two-loop quantum corrections to this potential and the corresponding sigma-model metric are explicitly found.

  9. Reformulating the TBA equations for the quark anti-quark potential and their two loop expansion

    International Nuclear Information System (INIS)

    Bajnok, Zoltán; Balog, János; Correa, Diego H.; Hegedűs, Árpád; Massolo, Fidel I. Schaposnik; Tóth, Gábor Zsolt

    2014-01-01

    The boundary thermodynamic Bethe Ansatz (BTBA) equations introduced in http://dx.doi.org/10.1007/JHEP08(2012)134http://dx.doi.org/10.1007/JHEP10(2013)135 to describe the cusp anomalous dimension contain imaginary chemical potentials and singular boundary fugacities, which make its systematic expansion problematic. We propose an alternative formulation based on real chemical potentials and additional source terms. We expand our equations to double wrapping order and find complete agreement with the direct two-loop gauge theory computation of the cusp anomalous dimension

  10. Perturbative study of the QCD phase diagram for heavy quarks at nonzero chemical potential: Two-loop corrections

    Science.gov (United States)

    Maelger, J.; Reinosa, U.; Serreau, J.

    2018-04-01

    We extend a previous investigation [U. Reinosa et al., Phys. Rev. D 92, 025021 (2015), 10.1103/PhysRevD.92.025021] of the QCD phase diagram with heavy quarks in the context of background field methods by including the two-loop corrections to the background field effective potential. The nonperturbative dynamics in the pure-gauge sector is modeled by a phenomenological gluon mass term in the Landau-DeWitt gauge-fixed action, which results in an improved perturbative expansion. We investigate the phase diagram at nonzero temperature and (real or imaginary) chemical potential. Two-loop corrections yield an improved agreement with lattice data as compared to the leading-order results. We also compare with the results of nonperturbative continuum approaches. We further study the equation of state as well as the thermodynamic stability of the system at two-loop order. Finally, using simple thermodynamic arguments, we show that the behavior of the Polyakov loops as functions of the chemical potential complies with their interpretation in terms of quark and antiquark free energies.

  11. The complete two-loop integrated jet thrust distribution in soft-collinear effective theory

    International Nuclear Information System (INIS)

    Manteuffel, Andreas von; Schabinger, Robert M.; Zhu, Hua Xing

    2014-01-01

    In this work, we complete the calculation of the soft part of the two-loop integrated jet thrust distribution in e + e − annihilation. This jet mass observable is based on the thrust cone jet algorithm, which involves a veto scale for out-of-jet radiation. The previously uncomputed part of our result depends in a complicated way on the jet cone size, r, and at intermediate stages of the calculation we actually encounter a new class of multiple polylogarithms. We employ an extension of the coproduct calculus to systematically exploit functional relations and represent our results concisely. In contrast to the individual contributions, the sum of all global terms can be expressed in terms of classical polylogarithms. Our explicit two-loop calculation enables us to clarify the small r picture discussed in earlier work. In particular, we show that the resummation of the logarithms of r that appear in the previously uncomputed part of the two-loop integrated jet thrust distribution is inextricably linked to the resummation of the non-global logarithms. Furthermore, we find that the logarithms of r which cannot be absorbed into the non-global logarithms in the way advocated in earlier work have coefficients fixed by the two-loop cusp anomalous dimension. We also show that in many cases one can straightforwardly predict potentially large logarithmic contributions to the integrated jet thrust distribution at L loops by making use of analogous contributions to the simpler integrated hemisphere soft function

  12. Two-loop disorder effects on the nematic quantum criticality in d-wave superconductors

    International Nuclear Information System (INIS)

    Wang, Jing

    2015-01-01

    The gapless nodal fermions exhibit non-Fermi liquid behaviors at the nematic quantum critical point that is supposed to exist in some d-wave cuprate superconductors. This non-Fermi liquid state may be turned into a disorder-dominated diffusive metal if the fermions also couple to a disordered potential that generates a relevant perturbation in the sense of renormalization group theory. It is therefore necessary to examine whether a specific disorder is relevant or not. We study the interplay between critical nematic fluctuation and random chemical potential by performing renormalization group analysis. The parameter that characterizes the strength of random chemical potential is marginal at the one-loop level, but becomes marginally relevant after including the two-loop corrections. Thus even weak random chemical potential leads to diffusive motion of nodal fermions and the significantly critical behaviors of physical implications, since the strength flows eventually to large values at low energies. - Highlights: • The gapless nodal fermions exhibit non-Fermi liquid behaviors at the nematic QCP. • The strength of random chemical potential is marginal at the one-loop level. • The strength becomes marginally relevant after including the two-loop corrections. • The diffusive metallic state is induced by the marginally relevant disorder. • The behaviors of some physical observables are presented at the nematic QCP

  13. Electroweak two-loop corrections to the effective weak mixing angle

    International Nuclear Information System (INIS)

    Awramik, Malgorzata; Czakon, Michal; Freitas, Ayres

    2006-01-01

    Recently exact results for the complete electroweak two-loop contributions to the effective weak mixing angle were published. This paper illustrates the techniques used for this computation, in particular the methods for evaluating the loop diagrams and the proper definition of Z-pole observables at next-to-next-to-leading order. Numerical results are presented in terms of simple parametrization formulae and compared in detail with a previous result of an expansion up to next-to-leading order in the top-quark mass. Finally, an estimate of the remaining theoretical uncertainties from unknown higher-order corrections is given

  14. Infrared divergences and harmonic anomalies in the two-loop superstring effective action

    CERN Document Server

    Pioline, Boris

    2015-01-01

    We analyze the pertubative contributions to the $D^4 R^4$ and $D^6 R^4$ couplings in the low-energy effective action of type II string theory compactified on a torus $T^d$, with particular emphasis on two-loop corrections. In general, it is necessary to introduce an infrared cut-off $\\Lambda$ to separate local interactions from non-local effects due to the exchange of massless states. We identify the degenerations of the genus-two Riemann surface which are responsible for power-like dependence on $\\Lambda$, and give an explicit prescription for extracting the $\\Lambda$-independent effective couplings. These renormalized couplings are then shown to be eigenmodes of the Laplace operator with respect to the torus moduli, up to computable anomalous source terms arising in the presence of logarithmic divergences, in precise agreement with predictions from U-duality. Our results for the two-loop $D^6 R^4$ contribution also probe essential properties of the Kawazumi-Zhang invariant

  15. Infrared divergences and harmonic anomalies in the two-loop superstring effective action

    Energy Technology Data Exchange (ETDEWEB)

    Pioline, Boris [CERN PH-TH,Case C01600, CERN, CH-1211 Geneva 23 (Switzerland); Sorbonne Universités,UPMC Université Paris 6, UMR 7589, F-75005 Paris (France); Laboratoire de Physique Théorique et Hautes Energies, CNRS UMR 7589,Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris cedex 05 (France); Russo, Rodolfo [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom)

    2015-12-16

    We analyze the pertubative contributions to the D{sup 4}R{sup 4} and D{sup 6}R{sup 4} couplings in the low-energy effective action of type II string theory compactified on a torus T{sup d}, with particular emphasis on two-loop corrections. In general, it is necessary to introduce an infrared cut-off Λ to separate local interactions from non-local effects due to the exchange of massless states. We identify the degenerations of the genus-two Riemann surface which are responsible for power-like dependence on Λ, and give an explicit prescription for extracting the Λ-independent effective couplings. These renormalized couplings are then shown to be eigenmodes of the Laplace operator with respect to the torus moduli, up to computable anomalous source terms arising in the presence of logarithmic divergences, in precise agreement with predictions from U-duality. Our results for the two-loop D{sup 6}R{sup 4} contribution also probe essential properties of the Kawazumi-Zhang invariant.

  16. The impact of two-loop effects on the scenario of MSSM Higgs alignment without decoupling

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Howard E.; Stefaniak, Tim [University of California, Santa Cruz Institute for Particle Physics (SCIPP) and Department of Physics, Santa Cruz, CA (United States); Heinemeyer, Sven [Campus of International Excellence UAM+CSIC, Madrid (Spain); Universidad Autonoma de Madrid, Instituto de Fisica Teorica, (UAM/CSIC), Madrid (Spain); Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain)

    2017-11-15

    In multi-Higgs models, the properties of one neutral scalar state approximate those of the Standard Model (SM) Higgs boson in a limit where the corresponding scalar field is roughly aligned in field space with the scalar doublet vacuum expectation value. In a scenario of alignment without decoupling, a SM-like Higgs boson can be accompanied by additional scalar states whose masses are of a similar order of magnitude. In the Minimal Supersymmetric Standard Model (MSSM), alignment without decoupling can be achieved due to an accidental cancellation of tree-level and radiative loop-level effects. In this paper we assess the impact of the leading two-loop O(α{sub s}h{sub t}{sup 2}) corrections on the Higgs alignment condition in the MSSM. These corrections are sizable and important in the relevant regions of parameter space and furthermore give rise to solutions of the alignment condition that are not present in the approximate one-loop description. We provide a comprehensive numerical comparison of the alignment condition obtained in the approximate one-loop and two-loop approximations, and discuss its implications for phenomenologically viable regions of the MSSM parameter space. (orig.)

  17. Two-Loop Effective Theory Analysis of π (K)→eνe[γ] Branching Ratios

    International Nuclear Information System (INIS)

    Cirigliano, Vincenzo; Rosell, Ignasi

    2007-01-01

    We study the ratios R e/μ (P) ≡Γ(P→eν e [γ])/Γ(P→μν μ [γ]) (P=π, K) in Chiral Perturbation Theory to order e 2 p 4 . We complement the two-loop effective theory results with a matching calculation of the counterterm, finding R e/μ (π) =(1.2352±0.0001)x10 -4 and R e/μ (K) =(2.477±0.001)x10 -5

  18. Two-loop N=4 super-Yang-Mills effective action and interaction between D3-branes

    International Nuclear Information System (INIS)

    Buchbinder, I.L.; Petrov, A.Yu.; Tseytlin, A.A.

    2002-01-01

    We compute the leading low-energy term in the planar part of the 2-loop contribution to the effective action of N=4 SYM theory in 4 dimensions, assuming that the gauge group SU(N+1) is broken to SU(N)xU(1) by a constant scalar background X. While the leading 1-loop correction is the familiar c 1 F 4 /vertical bar X vertical bar 4 term, the 2-loop expression starts with c 2 F 6 /vertical bar X vertical bar 8 . The 1-loop constant c 1 is known to be equal to the coefficient of the F 4 term in the Born-Infeld action for a probe D3-brane separated by distance vertical bar X vertical bar from a large number N of coincident D3-branes. We show that the same is true also for the 2-loop constant c 2 : it matches the coefficient of the F 6 term in the D3-brane probe action. In the context of the AdS/CFT correspondence, this agreement suggests a non-renormalization of the coefficient of the F 6 term beyond two loops. Thus the result of hep-th/9706072 about the agreement between the v 6 term in the D0-brane supergravity interaction potential and the corresponding 2-loop term in the (1+0)-dimensional reduction of N=4 SYM theory has indeed a direct generalization to 1+3 dimensions, as conjectured earlier in hep-th/9709087. We also discuss the issue of gauge theory-supergravity correspondence for higher order (F 8 , etc.) terms

  19. Topics in quantum chromodynamics: two loop Feynman gauge calculation of the meson nonsinglet evolution potential and fourier acceleration of the calculation of the fermion propagator in lattice QCD

    International Nuclear Information System (INIS)

    Katz, G.R.

    1986-01-01

    Part I of this thesis is a perturbative QCD calculation to two loops of the meson nonsinglet evolution potential in the Feynman gauge. The evolution potential describes the momentum dependence of the distribution amplitude. This amplitude is needed for the calculation to beyond leading order of exclusive amplitudes and form factors. Techniques are presented that greatly simplify the calculation. The results agree with an independent light-cone gauge calculation and disagree with predictions made using conformal symmetry. In Part II the author presents a Fourier acceleration method that is effective in accelerating the computation of the fermion propagator in lattice QCD. The conventional computation suffers from critical slowing down: the long distance structure converges much slower than the short distance structure. by evaluating the fermion propagator in momentum space using fast Fourier transforms, it is possible to make different length scales converge at a more equal rate. From numerical experiments made on a 8 4 lattice, the author obtained savings of a factor of 3 to 4 by using Fourier acceleration. He also discusses the important of gauge fixing when using Fourier acceleration

  20. Effects of two-loop contributions in the pseudofermion functional renormalization group method for quantum spin systems

    Science.gov (United States)

    Rück, Marlon; Reuther, Johannes

    2018-04-01

    We implement an extension of the pseudofermion functional renormalization group method for quantum spin systems that takes into account two-loop diagrammatic contributions. An efficient numerical treatment of the additional terms is achieved within a nested graph construction which recombines different one-loop interaction channels. In order to be fully self-consistent with respect to self-energy corrections, we also include certain three-loop terms of Katanin type. We first apply this formalism to the antiferromagnetic J1-J2 Heisenberg model on the square lattice and benchmark our results against the previous one-loop plus Katanin approach. Even though the renormalization group (RG) equations undergo significant modifications when including the two-loop terms, the magnetic phase diagram, comprising Néel ordered and collinear ordered phases separated by a magnetically disordered regime, remains remarkably unchanged. Only the boundary position between the disordered and the collinear phases is found to be moderately affected by two-loop terms. On the other hand, critical RG scales, which we associate with critical temperatures Tc, are reduced by a factor of ˜2 indicating that the two-loop diagrams play a significant role in enforcing the Mermin-Wagner theorem. Improved estimates for critical temperatures are also obtained for the Heisenberg ferromagnet on the three-dimensional simple cubic lattice where errors in Tc are reduced by ˜34 % . These findings have important implications for the quantum phase diagrams calculated within the previous one-loop plus Katanin approach which turn out to be already well converged.

  1. On the Kählerian symmetries of the two-loop action of the effective string theory

    CERN Document Server

    Ozkurt, S S

    2003-01-01

    Sometimes ago, it has been proposed in a paper by N.Kaloper and K.A.Meissner (\\PR {\\bf D56} (1997) 7940) that if one makes local redefinitions of fields, it does not change the equations of motion (in the redefined fields); however, this comment has not generally been accepted, namely, the redefined fields satisfy different equations of motion. For this reason, in this paper, it is proved that the whole action can be written as a square of the zeroth-order field equations. In this way, we show that any solution of the zeroth-order field equations, which has some K\\"{a}hler symmetry, at the same time, is also a solution of the two-loop equations.

  2. Two-Loop Splitting Amplitudes

    International Nuclear Information System (INIS)

    Bern, Z.

    2004-01-01

    Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method retains the simple factorization properties of light-cone gauge, but avoids the need for prescriptions such as the principal value or Mandelstam-Leibbrandt ones. The encountered loop momentum integrals are then evaluated using integration-by-parts and Lorentz invariance identities. We outline a variety of applications for these splitting amplitudes

  3. Two-loop splitting amplitudes

    International Nuclear Information System (INIS)

    Bern, Z.; Dixon, L.J.; Kosower, D.A.

    2004-01-01

    Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method retains the simple factorization properties of light-cone gauge, but avoids the need for prescriptions such as the principal value or Mandelstam-Leibbrandt ones. The encountered loop momentum integrals are then evaluated using integration-by-parts and Lorentz invariance identities. We outline a variety of applications for these splitting amplitudes

  4. A two-loop test of M(atrix) theory

    International Nuclear Information System (INIS)

    Becker, K.

    1997-01-01

    We consider the scattering of two Dirichlet zero-branes in M(atrix) theory. Using the formulation of M(atrix) theory in terms of ten-dimensional super Yang-Mills theory dimensionally reduced to (0+1) dimensions, we obtain the effective (velocity-dependent) potential describing these particles. At one loop we obtain the well-known result for the leading order of the effective potential V eff ∝v 4 /r 7 , where v and r are the relative velocity and distance between the two zero-branes, respectively. A calculation of the effective potential at two loops shows that no renormalizations of the v 4 term of the effective potential occur at this order. (orig.)

  5. Exact two-loop vacuum polarization correction to the Lamb shift in hydrogenlike ions

    International Nuclear Information System (INIS)

    Plunien, G.; Beier, T.; Soff, G.

    1998-01-01

    We present a calculation scheme for the two-loop vacuum polarization correction of order α 2 to the Lamb shift of hydrogenlike high-Z atoms. The interaction with the external Coulomb field is taken into account to all orders in (Zα). By means of a modified potential approach the problem is reduced to the evaluation of effective one-loop vacuumpolarization potentials. An expression for the energy shift is deduced within the framework of partial wave decomposition performing appropriate subtractions. Exact results for the two-loop vacuum polarization contribution to the Lamb shift of K- and L-shell electron states in hydrogenlike lead and uranium are presented. (orig.)

  6. Effect of Spray System on Fission Product Distribution in Containment During a Severe Accident in a Two-Loop Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Mehdi Dehjourian

    2016-08-01

    Full Text Available The containment response during the first 24 hours of a low-pressure severe accident scenario in a nuclear power plant with a two-loop Westinghouse-type pressurized water reactor was simulated with the CONTAIN 2.0 computer code. The accident considered in this study is a large-break loss-of-coolant accident, which is not successfully mitigated by the action of safety systems. The analysis includes pressure and temperature responses, as well as investigation into the influence of spray on the retention of fission products and the prevention of hydrogen combustion in the containment.

  7. Two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories

    Directory of Open Access Journals (Sweden)

    Junji Hisano

    2017-09-01

    Full Text Available We derive two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories using the effective Kähler potential. We introduce the general forms in generic gauge theories and apply our results to the flavor-changing operators in (minimal supersymmetric standard models.

  8. Higgs Decay to Photons at Two Loops

    International Nuclear Information System (INIS)

    Fugel, F.

    2007-01-01

    The calculation of the two-loop corrections to the partial width of an intermediate-mass Higgs boson decaying into a pair of photons is reviewed. The main focus lies on the electroweak (EW) contributions. The sum of the EW corrections ranges from -4% to 0% for a Higgs mass between 100 GeV and 150 GeV, while the complete correction at two-loop order amounts to less than ± 1.5% in this regime. (author)

  9. The two-loop renormalization of general quantum field theories

    International Nuclear Information System (INIS)

    Damme, R.M.J. van.

    1984-01-01

    This thesis provides a general method to compute all first order corrections to the renormalization group equations. This requires the computation of the first perturbative corrections to the renormalization group β-functions. These corrections are described by Feynman diagrams with two loops. The two-loop renormalization is treated for an arbitrary renormalization field theory. Two cases are considered: 1. the Yukawa sector; 2. the gauge coupling and the scalar potential. In a final section, the breakdown of unitarity in the dimensional reduction scheme is discussed. (Auth.)

  10. Two-loop electroweak top corrections are they under control?

    CERN Document Server

    Degrassi, G.; Feruglio, F.; Gambino, P.; Vicini, A.; Degrassi, G; Fanchiotti, S; Feruglio, F; Gambino, P; Vicini, A

    1995-01-01

    The assumption that two-loop top corrections are well approximated by the O(G_mu^2 mt^4) contribution is investigated. It is shown that in the case of the ratio neutral-to-charged current amplitudes at zero momentum transfer the O(G_mu^2 mt^2 M_Z^2) terms are numerically comparable to the m_t^4 contribution for realistic values of the top mass. An estimate of the theoretical error due to unknown two-loop top effect is presented for a few observables of LEP interest.

  11. The SU(2|3) dynamic two-loop form factors

    International Nuclear Information System (INIS)

    Brandhuber, A.; Kostacińska, M.; Penante, B.; Travaglini, G.; Young, D.

    2016-01-01

    We compute two-loop form factors of operators in the SU(2|3) closed subsector of N = 4 supersymmetric Yang-Mills. In particular, we focus on the non-protected, dimension-three operators Tr(X[Y,Z]) and Tr(ψψ) for which we compute the four possible two-loop form factors, and corresponding remainder functions, with external states 〈X̄ȲZ̄| and 〈ψ̄ψ̄|. Interestingly, the maximally transcendental part of the two-loop remainder of 〈X̄ȲZ̄|Tr(X[Y,Z])|0〉 turns out to be identical to that of the corresponding known quantity for the half-BPS operator Tr(X"3). We also find a surprising connection between the terms subleading in transcendentality and certain a priori unrelated remainder densities introduced in the study of the spin chain Hamiltonian in the SU(2) sector. Next, we use our calculation to resolve the mixing, recovering anomalous dimensions and eigenstates of the dilatation operator in the SU(2|3) sector at two loops. We also speculate on potential connections between our calculations in N = 4 super Yang-Mills and Higgs + multi-gluon amplitudes in QCD in an effective Lagrangian approach.

  12. The SU(2|3) dynamic two-loop form factors

    Energy Technology Data Exchange (ETDEWEB)

    Brandhuber, A.; Kostacińska, M. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Penante, B. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Institut für Physik und IRIS Adlershof, Humboldt Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Travaglini, G.; Young, D. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom)

    2016-08-23

    We compute two-loop form factors of operators in the SU(2|3) closed subsector of N = 4 supersymmetric Yang-Mills. In particular, we focus on the non-protected, dimension-three operators Tr(X[Y,Z]) and Tr(ψψ) for which we compute the four possible two-loop form factors, and corresponding remainder functions, with external states 〈X̄ȲZ̄| and 〈ψ̄ψ̄|. Interestingly, the maximally transcendental part of the two-loop remainder of 〈X̄ȲZ̄|Tr(X[Y,Z])|0〉 turns out to be identical to that of the corresponding known quantity for the half-BPS operator Tr(X{sup 3}). We also find a surprising connection between the terms subleading in transcendentality and certain a priori unrelated remainder densities introduced in the study of the spin chain Hamiltonian in the SU(2) sector. Next, we use our calculation to resolve the mixing, recovering anomalous dimensions and eigenstates of the dilatation operator in the SU(2|3) sector at two loops. We also speculate on potential connections between our calculations in N = 4 super Yang-Mills and Higgs + multi-gluon amplitudes in QCD in an effective Lagrangian approach.

  13. Two-loop matching coefficients for heavy quark currents

    International Nuclear Information System (INIS)

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

    2006-04-01

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

  14. Two-loop Higgs mass calculations beyond the MSSM with SARAH and SPheno

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, Kilian [Physikalisches Institut, Universitaet Bonn (Germany); Staub, Florian [Theory Division, CERN, Geneva (Switzerland); Goodsell, Mark [LPTHE, UPMC Univ. Paris 06 (France)

    2015-07-01

    We present a recent extension to the Mathematica package SARAH which allows for Higgs mass calculations at the two-loop level in a wide range of supersymmetric models beyond the MSSM. These calculations are based on the effective potential approach. For the numerical evaluation Fortran code for SPheno is generated by SARAH. This allows to predict the Higgs mass in more complicated SUSY theories with a similar precision as most state-of-the-art spectrum generators do for the MSSM.

  15. The quark beam function at two loops

    International Nuclear Information System (INIS)

    Gaunt, Jonathan R.; Stahlhofen, Maximilian; Tackmann, Frank J.

    2014-01-01

    In differential measurements at a hadron collider, collinear initial-state radiation is described by process-independent beam functions. They are the field-theoretic analog of initial-state parton showers. Depending on the measured observable they are differential in the virtuality and/or transverse momentum of the colliding partons in addition to their usual longitudinal momentum fractions. Perturbatively, the beam functions can be calculated by matching them onto standard quark and gluon parton distribution functions. We calculate the inclusive virtuality-dependent quark beam function at NNLO, which is relevant for any observables probing the virtuality of the incoming partons, including N-jettiness and beam thrust. For such observables, our results are an important ingredient in the resummation of large logarithms at N 3 LL order, and provide all contributions enhanced by collinear t-channel singularities at NNLO for quark-initiated processes in analytic form. We perform the calculation in both Feynman and axial gauge and use two different methods to evaluate the discontinuity in the two-loop Feynman diagrams, providing nontrivial checks of the calculation. As part of our results we reproduce the known two-loop QCD splitting functions and confirm at two loops that the virtuality-dependent beam and final-state jet functions have the same anomalous dimension.

  16. Two loop integrals and QCD scattering

    International Nuclear Information System (INIS)

    Anastasiou, C.

    2001-04-01

    We present the techniques for the calculation of one- and two-loop integrals contributing to the virtual corrections to 2→2 scattering of massless particles. First, tensor integrals are related to scalar integrals with extra powers of propagators and higher dimension using the Schwinger representation. Integration By Parts and Lorentz Invariance recurrence relations reduce the number of independent scalar integrals to a set of master integrals for which their expansion in ε = 2 - D/2 is calculated using a combination of Feynman parameters, the Negative Dimension Integration Method, the Differential Equations Method, and Mellin-Barnes integral representations. The two-loop matrix-elements for light-quark scattering are calculated in Conventional Dimensional Regularisation by direct evaluation of the Feynman diagrams. The ultraviolet divergences are removed by renormalising with the MS-bar scheme. Finally, the infrared singular behavior is shown to be in agreement with the one anticipated by the application of Catani's formalism for the infrared divergences of generic QCD two-loop amplitudes. (author)

  17. Two-loop renormalization of quantum gravity simplified

    Science.gov (United States)

    Bern, Zvi; Chi, Huan-Hang; Dixon, Lance; Edison, Alex

    2017-02-01

    The coefficient of the dimensionally regularized two-loop R3 divergence of (nonsupersymmetric) gravity theories has recently been shown to change when nondynamical three-forms are added to the theory, or when a pseudoscalar is replaced by the antisymmetric two-form field to which it is dual. This phenomenon involves evanescent operators, whose matrix elements vanish in four dimensions, including the Gauss-Bonnet operator which is also connected to the trace anomaly. On the other hand, these effects appear to have no physical consequences for renormalized scattering processes. In particular, the dependence of the two-loop four-graviton scattering amplitude on the renormalization scale is simple. We explain this result for any minimally-coupled massless gravity theory with renormalizable matter interactions by using unitarity cuts in four dimensions and never invoking evanescent operators.

  18. New two-loop contribution to electric dipole moment in supersymmetric theories

    CERN Document Server

    Chang, Darwin; Pilaftsis, Apostolos; Chang, Darwin; Keung, Wai-Yee; Pilaftsis, Apostolos

    1999-01-01

    We calculate a new type of two-loop contributions to the electric dipole moments of the electron and neutron in supersymmetric theories. The new contributions are originated from the potential CP violation in the trilinear couplings of the Higgs bosons to the scalar-top or the scalar-bottom quarks. These couplings were previously very weakly constrained. The electric dipole moments are induced through a mechanism analogous to that due to Barr and Zee. We find observable effects for a sizeable portion of the parameter space related to the third generation scalar-quarks in the minimal supersymmetric standard model which cannot be excluded by earlier considerations.

  19. XLOOPS - a package calculating one- and two-loop diagrams

    International Nuclear Information System (INIS)

    Bruecher, L.

    1997-01-01

    A program package for calculating massive one- and two-loop diagrams is introduced. It consists of five parts: - a graphical user interface, - routines for generating diagrams from particle input, - procedures for calculating one-loop integrals both analytically and numerically, - routines for massive two-loop integrals, - programs for numerical integration of two-loop diagrams. Here the graphical user interface and the text interface to Maple are presented. (orig.)

  20. Determination of the two-loop Lamb shift in lithiumlike bismuth

    International Nuclear Information System (INIS)

    Sapirstein, J.; Cheng, K. T.

    2001-01-01

    The energy levels of lithiumlike bismuth are shown to be accurately described in a representation-independent manner when all diagrams involving one and two photons, with the exception of the two-loop Lamb shift, are evaluated. Comparison with the experimental value of the 2p 3/2 -2s 1/2 splitting then shows that, assuming three-photon effects are negligible, the contribution of the two-loop Lamb shift is 0.175(39) eV

  1. Two-loop corrections to the ρ parameter in Two-Higgs-Doublet models

    Energy Technology Data Exchange (ETDEWEB)

    Hessenberger, Stephan; Hollik, Wolfgang [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany)

    2017-03-15

    Models with two scalar doublets are among the simplest extensions of the Standard Model which fulfill the relation ρ = 1 at lowest order for the ρ parameter as favored by experimental data for electroweak observables allowing only small deviations from unity. Such small deviations Δρ originate exclusively from quantum effects with special sensitivity to mass splittings between different isospin components of fermions and scalars. In this paper the dominant two-loop electroweak corrections to Δρ are calculated in the CP-conserving THDM, resulting from the top-Yukawa coupling and the self-couplings of the Higgs bosons in the gauge-less limit. The on-shell renormalization scheme is applied. With the assumption that one of the CP-even neutral scalars represents the scalar boson observed by the LHC experiments, with standard properties, the two-loop non-standard contributions in Δρ can be separated from the standard ones. These contributions are of particular interest since they increase with mass splittings between non-standard Higgs bosons and can be additionally enhanced by tanβ and λ{sub 5}, an additional free coefficient of the Higgs potential, and can thus modify the one-loop result substantially. Numerical results are given for the dependence on the various non-standard parameters, and the influence on the calculation of electroweak precision observables is discussed. (orig.)

  2. The massless two-loop two-point function

    International Nuclear Information System (INIS)

    Bierenbaum, I.; Weinzierl, S.

    2003-01-01

    We consider the massless two-loop two-point function with arbitrary powers of the propagators and derive a representation from which we can obtain the Laurent expansion to any desired order in the dimensional regularization parameter ε. As a side product, we show that in the Laurent expansion of the two-loop integral only rational numbers and multiple zeta values occur. Our method of calculation obtains the two-loop integral as a convolution product of two primitive one-loop integrals. We comment on the generalization of this product structure to higher loop integrals. (orig.)

  3. Two-loop mass splittings in electroweak multiplets: Winos and minimal dark matter

    Science.gov (United States)

    McKay, James; Scott, Pat

    2018-03-01

    The radiatively-induced splitting of masses in electroweak multiplets is relevant for both collider phenomenology and dark matter. Precision two-loop corrections of O (MeV ) to the triplet mass splitting in the wino limit of the minimal supersymmetric standard model can affect particle lifetimes by up to 40%. We improve on previous two-loop self-energy calculations for the wino model by obtaining consistent input parameters to the calculation via two-loop renormalization-group running, and including the effect of finite light quark masses. We also present the first two-loop calculation of the mass splitting in an electroweak fermionic quintuplet, corresponding to the viable form of minimal dark matter (MDM). We place significant constraints on the lifetimes of the charged and doubly-charged fermions in this model. We find that the two-loop mass splittings in the MDM quintuplet are not constant in the large-mass limit, as might naively be expected from the triplet calculation. This is due to the influence of the additional heavy fermions in loop corrections to the gauge boson propagators.

  4. The Higgs Mass in the MSSM at two-loop order beyond minimal flavour violation

    CERN Document Server

    Goodsell, Mark D; Staub, Florian

    2016-01-01

    Soft supersymmetry-breaking terms provide a wealth of new potential sources of flavour violation, which lead to very tight constraints from precision experiments. This has posed a challenge to construct flavour models to both explain the structure of the Standard Model Yukawa couplings and how their consequent predictions for patterns in the soft supersymmetry-breaking terms do not violate these constraints. While such models have been studied in great detail, the impact of flavour violating soft terms on the Higgs mass at the two-loop level has been assumed to be small or negligible. In this letter, we show that large flavour violation in the up-squark sector can give a positive or negative shift to the SM-like Higgs of several GeV, without being in conflict with any other observation. We investigate in which regions of the parameter space these effects can be expected.

  5. Two-loop hard-thermal-loop thermodynamics with quarks

    International Nuclear Information System (INIS)

    Andersen, Jens O.; Petitgirard, Emmanuel; Strickland, Michael

    2004-01-01

    We calculate the quark contribution to the free energy of a hot quark-gluon plasma to two-loop order using hard-thermal-loop (HTL) perturbation theory. All ultraviolet divergences can be absorbed into renormalizations of the vacuum energy and the HTL quark and gluon mass parameters. The quark and gluon HTL mass parameters are determined self-consistently by a variational prescription. Combining the quark contribution with the two-loop HTL perturbation theory free energy for pure glue we obtain the total two-loop QCD free energy. Comparisons are made with lattice estimates of the free energy for N f =2 and with exact numerical results obtained in the large-N f limit

  6. Description of the two-loop RELAP5 model of the L-Reactor at the Savannah River Site

    International Nuclear Information System (INIS)

    Cozzuol, J.M.; Davis, C.B.

    1989-12-01

    A two-loop RELAP5 input model of the L-Reactor at the Savannah River Site (SRS) was developed to support thermal-hydraulic analysis of SRS reactors. The model was developed to economically evaluate potential design changes. The primary simplifications in the model were in the number of loops and the detail in the moderator tank. The six loops in the reactor were modeled with two loops, one representing a single loop and the other representing five combined loops. The model has undergone a quality assurance review. This report describes the two-loop model, its limitations, and quality assurance. 29 refs., 18 figs., 10 tabs

  7. Two-loop off-shell QCD amplitudes in FDR

    CERN Document Server

    Page, Ben

    2015-01-01

    We link the FDR treatment of ultraviolet (UV) divergences to dimensional regularization up to two loops in QCD. This allows us to derive the one-loop and two-loop coupling constant and quark mass shifts necessary to translate infrared finite quantities computed in FDR to the MSbar renormalization scheme. As a by-product of our analysis, we solve a problem analogous to the breakdown of unitarity in the Four Dimensional Helicity (FDH) method beyond one loop. A fix to FDH is then presented that preserves the renormalizability properties of QCD without introducing evanescent quantities.

  8. Two-loop RGE of a general renormalizable Yang-Mills theory in a renormalization scheme with an explicit UV cutoff

    Energy Technology Data Exchange (ETDEWEB)

    Chankowski, Piotr H. [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland); Lewandowski, Adrian [Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut),Mühlenberg 1, D-14476 Potsdam (Germany); Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland); Meissner, Krzysztof A. [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland)

    2016-11-18

    We perform a systematic one-loop renormalization of a general renormalizable Yang-Mills theory coupled to scalars and fermions using a regularization scheme with a smooth momentum cutoff Λ (implemented through an exponential damping factor). We construct the necessary finite counterterms restoring the BRST invariance of the effective action by analyzing the relevant Slavnov-Taylor identities. We find the relation between the renormalized parameters in our scheme and in the conventional (MS)-bar scheme which allow us to obtain the explicit two-loop renormalization group equations in our scheme from the known two-loop ones in the (MS)-bar scheme. We calculate in our scheme the divergences of two-loop vacuum graphs in the presence of a constant scalar background field which allow us to rederive the two-loop beta functions for parameters of the scalar potential. We also prove that consistent application of the proposed regularization leads to counterterms which, together with the original action, combine to a bare action expressed in terms of bare parameters. This, together with treating Λ as an intrinsic scale of a hypothetical underlying finite theory of all interactions, offers a possibility of an unconventional solution to the hierarchy problem if no intermediate scales between the electroweak scale and the Planck scale exist.

  9. Higgs bosons and QCD jets at two loops

    International Nuclear Information System (INIS)

    Koukoutsakis, Athanasios

    2003-04-01

    In this thesis we present techniques for the calculation of two-loop integrals contributing to the virtual corrections to physical processes with three on-shell and one off-shell external particles. First, we describe a set of basic tools that simplify the manipulation of complicated two-loop integrals. A technique for deriving helicity amplitudes with use of a set of projectors is demonstrated. Then we present an algorithm, introduced by Laporta, that helps reduce all possible two-loop integrals to a basic set of 'master integrals'. Subsequently, these master integrals are analytically evaluated by deriving and solving differential equations on the external scales of the process. Two-loop matrix elements and helicity amplitudes are calculated for the physical processes γ* → qq-barg and H → ggg respectively. Conventional Dimensional Regularization is used in the evaluation of Feynman diagrams. For both processes the infrared singular behavior is shown to agree with the one predicted by Catani. (author)

  10. Comments on two-loop Kac-Moody algebras

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, L A; Gomes, J F; Zimerman, A H [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Schwimmer, A [Istituto Nazionale di Fisica Nucleare, Trieste (Italy)

    1991-10-01

    It is shown that the two-loop Kac-Moody algebra is equivalent to a two variable loop algebra and a decouple {beta}-{gamma} system. Similarly WZNW and CSW models having as algebraic structure the Kac-Moody algebra are equivalent to an infinity to versions of the corresponding ordinary models and decoupled Abelian fields. (author). 15 refs.

  11. Elastic ππ scattering to two loops

    International Nuclear Information System (INIS)

    Bijnens, J.; Colangelo, G.; Gasser, J.; Ecker, G.; Sainio, M.E.

    1995-11-01

    We evaluate analytically the elastic ππ scattering amplitude to two loops in chiral perturbation theory and give numerical values for the two S-wave scattering lengths and for the phase shift difference δ 0 0 -δ 1 1 . (author)

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

    International Nuclear Information System (INIS)

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

    2017-11-01

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

  13. The two loop superstring vacuum amplitude and canonical divisors

    International Nuclear Information System (INIS)

    Parkes, A.

    1989-01-01

    I use the prescription of placing the picture changing operators at the zeroes of some holomorphic one-form and calculate the two loop superstring vacuum amplitude in the language of theta functions. It vanishes pointwise on moduli space after the use of Fay's trisecant identity and generalised Riemann identities. I briefly discuss the higher genus case. (orig.)

  14. Two-loop neutrino model with exotic leptons

    Science.gov (United States)

    Okada, Hiroshi; Orikasa, Yuta

    2016-01-01

    We propose a two-loop induced neutrino mass model, in which we show some bench mark points to satisfy the observed neutrino oscillation, the constraints of lepton flavor violations, and the relic density in the coannihilation system satisfying the current upper bound on the spin independent scattering cross section with nuclei. We also discuss new sources of muon anomalous magnetic moments.

  15. Two-loop polygon Wilson loops in N = 4 SYM

    International Nuclear Information System (INIS)

    Anastasiou, C.; Brandhuber, A.; Heslop, P.; Spence, B.; Travaglini, G.; Khoze, V.V.

    2009-01-01

    We compute for the first time the two-loop corrections to arbitrary n-gon lightlike Wilson loops in N = 4 supersymmetric Yang-Mills theory, using efficient numerical methods. The calculation is motivated by the remarkable agreement between the finite part of planar six-point MHV amplitudes and hexagon Wilson loops which has been observed at two loops. At n = 6 we confirm that the ABDK/BDS ansatz must be corrected by adding a remainder function, which depends only on conformally invariant ratios of kinematic variables. We numerically compute remainder functions for n = 7,8 and verify dual conformal invariance. Furthermore, we study simple and multiple collinear limits of the Wilson loop remainder functions and demonstrate that they have precisely the form required by the collinear factorisation of the corresponding two-loop n-point amplitudes. The number of distinct diagram topologies contributing to the n-gon Wilson loops does not increase with n, and there is a fixed number of 'master integrals', which we have computed. Thus we have essentially computed general polygon Wilson loops, and if the correspondence with amplitudes continues to hold, all planar n-point two-loop MHV amplitudes in the N = 4 theory.

  16. The heavy quark form factors at two loops

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-12-15

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

  17. Supersymmetric Regularization Two-Loop QCD Amplitudes and Coupling Shifts

    International Nuclear Information System (INIS)

    Dixon, Lance

    2002-01-01

    We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It amounts to a variation on the standard 't Hooft-Veltman scheme and is designed to be compatible with the use of helicity states for ''observed'' particles. It is similar to dimensional reduction in that it maintains an equal number of bosonic and fermionic states, as required for preserving supersymmetry. Supersymmetry Ward identities relate different helicity amplitudes in supersymmetric theories. As a check that the FDH scheme preserves supersymmetry, at least through two loops, we explicitly verify a number of these identities for gluon-gluon scattering (gg → gg) in supersymmetric QCD. These results also cross-check recent non-trivial two-loop calculations in ordinary QCD. Finally, we compute the two-loop shift between the FDH coupling and the standard MS coupling, α s . The FDH shift is identical to the one for dimensional reduction. The two-loop coupling shifts are then used to obtain the three-loop QCD β function in the FDH and dimensional reduction schemes

  18. Supersymmetric Regularization Two-Loop QCD Amplitudes and Coupling Shifts

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Lance

    2002-03-08

    We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It amounts to a variation on the standard 't Hooft-Veltman scheme and is designed to be compatible with the use of helicity states for ''observed'' particles. It is similar to dimensional reduction in that it maintains an equal number of bosonic and fermionic states, as required for preserving supersymmetry. Supersymmetry Ward identities relate different helicity amplitudes in supersymmetric theories. As a check that the FDH scheme preserves supersymmetry, at least through two loops, we explicitly verify a number of these identities for gluon-gluon scattering (gg {yields} gg) in supersymmetric QCD. These results also cross-check recent non-trivial two-loop calculations in ordinary QCD. Finally, we compute the two-loop shift between the FDH coupling and the standard {bar M}{bar S} coupling, {alpha}{sub s}. The FDH shift is identical to the one for dimensional reduction. The two-loop coupling shifts are then used to obtain the three-loop QCD {beta} function in the FDH and dimensional reduction schemes.

  19. Finite volume at two-loops in chiral perturbation theory

    International Nuclear Information System (INIS)

    Bijnens, Johan; Rössler, Thomas

    2015-01-01

    We calculate the finite volume corrections to meson masses and decay constants in two and three flavour Chiral Perturbation Theory to two-loop order. The analytical results are compared with the existing result for the pion mass in two-flavour ChPT and the partial results for the other quantities. We present numerical results for all quantities.

  20. Two-loop feed water control system in BWR plants

    International Nuclear Information System (INIS)

    Omori, Takashi; Watanabe, Takao; Hirose, Masao.

    1982-01-01

    In the process of the start-up and shutdown of BWR plants, the operation of changing over feed pumps corresponding to plant output is performed. Therefore, it is necessary to develop the automatic changeover system for feed pumps, which minimizes the variation of water level in reactors and is easy to operate. The three-element control system with the water level in reactors, the flow rate of main steam and the flow rate of feed water as the input is mainly applied, but long time is required for the changeover of feed pumps. The two-loop feed control system can control simultaneously two pumps being changed over, therefore it is suitable to the automatic changeover control system for feed pumps. Also it is excellent for the control of the recirculating valves of feed pumps. The control characteristics of the two-loop feed water control system against the external disturbance which causes the variation of water level in reactors were examined. The results of analysis by simulation are reported. The features of the two-loop feed water control system, the method of simulation and the evaluation of the two-loop feed water control system are described. Its connection with a digital feed water recirculation control system is expected. (Kako, I.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-15

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

  2. Two-loop SL(2) form factors and maximal transcendentality

    International Nuclear Information System (INIS)

    Loebbert, Florian; Sieg, Christoph; Wilhelm, Matthias; Yang, Gang

    2016-01-01

    Form factors of composite operators in the SL(2) sector of N=4 SYM theory are studied up to two loops via the on-shell unitarity method. The non-compactness of this subsector implies the novel feature and technical challenge of an unlimited number of loop momenta in the integrand’s numerator. At one loop, we derive the full minimal form factor to all orders in the dimensional regularisation parameter. At two loops, we construct the complete integrand for composite operators with an arbitrary number of covariant derivatives, and we obtain the remainder functions as well as the dilatation operator for composite operators with up to three covariant derivatives. The remainder functions reveal curious patterns suggesting a hidden maximal uniform transcendentality for the full form factor. Finally, we speculate about an extension of these patterns to QCD.

  3. Two-loop SL(2) form factors and maximal transcendentality

    Energy Technology Data Exchange (ETDEWEB)

    Loebbert, Florian [Institut für Physik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Sieg, Christoph [Institut für Physik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Institut für Mathematik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Wilhelm, Matthias [Institut für Physik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Institut für Mathematik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Niels Bohr Institute, Copenhagen University,Blegdamsvej 17, 2100 Copenhagen Ø (Denmark); Yang, Gang [CAS Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Beijing 100190 (China); Institut für Physik, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany)

    2016-12-19

    Form factors of composite operators in the SL(2) sector of N=4 SYM theory are studied up to two loops via the on-shell unitarity method. The non-compactness of this subsector implies the novel feature and technical challenge of an unlimited number of loop momenta in the integrand’s numerator. At one loop, we derive the full minimal form factor to all orders in the dimensional regularisation parameter. At two loops, we construct the complete integrand for composite operators with an arbitrary number of covariant derivatives, and we obtain the remainder functions as well as the dilatation operator for composite operators with up to three covariant derivatives. The remainder functions reveal curious patterns suggesting a hidden maximal uniform transcendentality for the full form factor. Finally, we speculate about an extension of these patterns to QCD.

  4. Two-loop Dirac neutrino mass and WIMP dark matter

    OpenAIRE

    Bonilla, Cesar; Ma, Ernest; Peinado, Eduardo; Valle, Jose W.F.

    2018-01-01

    We propose a "scotogenic" mechanism relating small neutrino mass and cosmological dark matter. Neutrinos are Dirac fermions with masses arising only in two--loop order through the sector responsible for dark matter. Two triality symmetries ensure both dark matter stability and strict lepton number conservation at higher orders. A global spontaneously broken U(1) symmetry leads to a physical $Diracon$ that induces invisible Higgs decays which add up to the Higgs to dark matter mode. This enhan...

  5. Avoiding the Goldstone Boson Catastrophe in general renormalisable field theories at two loops

    Energy Technology Data Exchange (ETDEWEB)

    Braathen, Johannes; Goodsell, Mark D. [LPTHE, UPMC University Paris 06, Sorbonne Universités,4 Place Jussieu, F-75252 Paris (France); LPTHE, CNRS,4 Place Jussieu, F-75252 Paris (France)

    2016-12-14

    We show how the infra-red divergences associated to Goldstone bosons in the minimum condition of the two-loop Landau-gauge effective potential can be avoided in general field theories. This extends the resummation formalism recently developed for the Standard Model and the MSSM, and we give compact, infra-red finite expressions in closed form for the tadpole equations. We also show that the results at this loop order are equivalent to (and are most easily obtained by) imposing an “on-shell” condition for the Goldstone bosons. Moreover, we extend the approach to show how the infra-red divergences in the calculation of the masses of neutral scalars (such as the Higgs boson) can be eliminated. For the mass computation, we specialise to the gaugeless limit and extend the effective potential computation to allow the masses to be determined without needing to solve differential equations for the loop functions — opening the door to fast, infra-red safe determinations of the Higgs mass in general theories.

  6. The muon magnetic moment in the 2HDM: complete two-loop result

    International Nuclear Information System (INIS)

    Cherchiglia, Adriano; Kneschke, Patrick; Stöckinger, Dominik; Stöckinger-Kim, Hyejung

    2017-01-01

    We study the 2HDM contribution to the muon anomalous magnetic moment a μ and present the complete two-loop result, particularly for the bosonic contribution. We focus on the Aligned 2HDM, which has general Yukawa couplings and contains the type I, II, X, Y models as special cases. The result is expressed with physical parameters: three Higgs boson masses, Yukawa couplings, two mixing angles, and one quartic potential parameter. We show that the result can be split into several parts, each of which has a simple parameter dependence, and we document their general behavior. Taking into account constraints on parameters, we find that the full 2HDM contribution to a μ can accommodate the current experimental value, and the complete two-loop bosonic contribution can amount to (2⋯4)×10 −10 , more than the future experimental uncertainty.

  7. Parton-parton scattering at two-loops

    International Nuclear Information System (INIS)

    Tejeda Yeomans, M.E.

    2001-01-01

    Abstract We present an algorithm for the calculation of scalar and tensor one- and two-loop integrals that contribute to the virtual corrections of 2 → 2 partonic scattering. First, the tensor integrals are related to scalar integrals that contain an irreducible propagator-like structure in the numerator. Then, we use Integration by Parts and Lorentz Invariance recurrence relations to build a general system of equations that enables the reduction of any scalar integral (with and without structure in the numerator) to a basis set of master integrals. Their expansions in ε = 2 - D/2 have already been calculated and we present a summary of the techniques that have been used to this end, as well as a compilation of the expansions we need in the different physical regions. We then apply this algorithm to the direct evaluation of the Feynman diagrams contributing to the O(α s 4 ) one- and two-loop matrix-elements for massless like and unlike quark-quark, quark-gluon and gluon-gluon scattering. The analytic expressions we provide are regularised in Convensional Dimensional Regularisation and renormalised in the MS-bar scheme. Finally, we show that the structure of the infrared divergences agrees with that predicted by the application of Catani's formalism to the analysis of each partonic scattering process. The results presented in this thesis provide the complete calculation of the one- and two-loop matrix-elements for 2 → 2 processes needed for the next-to-next-to-leading order contribution to inclusive jet production at hadron colliders. (author)

  8. Two-loop ladder diagram contributions to Bhabha scattering. III

    International Nuclear Information System (INIS)

    Bjoerkevoll, K.S.; Osland, P.; Faeldt, G.

    1992-01-01

    The authors evaluate, in the high-energy limit, the sum of the Feynman amplitudes corresponding the six two-loop ladder-like diagrams in Bhabha scattering. This is the limit where s→∞, while t, the electron mass m and the photon mass λ are all being held fixed. In this limit the sum of the six Feynman amplitudes does not depend on the electron mass. When specialized to the region s>>t>>m 2 >>λ 2 , this result complements the one previously obtained. The connection with Φ 3 theory is also investigated. 6 refs

  9. Two-loop string theory on null compactifications

    International Nuclear Information System (INIS)

    Cove, Henry C.D.; Szabo, Richard J.

    2006-01-01

    We compute the two-loop contributions to the free energy in the null compactification of perturbative string theory at finite temperature. The cases of bosonic, type II and heterotic strings are all treated. The calculation exploits an explicit reductive parametrization of the moduli space of infinite-momentum frame string worldsheets in terms of branched cover instantons. Various arithmetic and physical properties of the instanton sums are described. Applications to symmetric product orbifold conformal field theories and to the matrix string theory conjecture are also briefly discussed

  10. Two-Loop Scattering Amplitudes from the Riemann Sphere

    CERN Document Server

    Geyer, Yvonne; Monteiro, Ricardo; Tourkine, Piotr

    2016-01-01

    The scattering equations give striking formulae for massless scattering amplitudes at tree level and, as shown recently, at one loop. The progress at loop level was based on ambitwistor string theory, which naturally yields the scattering equations. We proposed that, for ambitwistor strings, the standard loop expansion in terms of the genus of the worldsheet is equivalent to an expansion in terms of nodes of a Riemann sphere, with the nodes carrying the loop momenta. In this paper, we show how to obtain two-loop scattering equations with the correct factorization properties. We adapt genus-two integrands from the ambitwistor string to the nodal Riemann sphere and show that these yield correct answers, by matching standard results for the four-point two-loop amplitudes of maximal supergravity and super-Yang-Mills theory. In the Yang-Mills case, this requires the loop analogue of the Parke-Taylor factor carrying the colour dependence, which includes non-planar contributions.

  11. Two-loop fermionic corrections to massive Bhabha scattering

    Energy Technology Data Exchange (ETDEWEB)

    Actis, S.; Riemann, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Czakon, M. [Wuerzburg Univ. (Germany). Inst. fuer Theoretische Physik und Astrophysik]|[Institute of Nuclear Physics, NSCR DEMOKRITOS, Athens (Greece); Gluza, J. [Silesia Univ., Katowice (Poland). Inst. of Physics

    2007-05-15

    We evaluate the two-loop corrections to Bhabha scattering from fermion loops in the context of pure Quantum Electrodynamics. The differential cross section is expressed by a small number of Master Integrals with exact dependence on the fermion masses m{sub e}, m{sub f} and the Mandelstam invariants s, t, u. We determine the limit of fixed scattering angle and high energy, assuming the hierarchy of scales m{sup 2}{sub e}<

  12. Massive two-loop Bhabha scattering - the factorizable subset

    International Nuclear Information System (INIS)

    Fleischer, J.; Tarasov, O.V.; Werthenbach, A.

    2002-11-01

    The experimental precision that will be reached at the next generation of colliders makes it indispensable to improve theoretical predictions significantly. Bhabha scattering (e + e - → e + e - ) is one of the prime processes calling for a better theoretical precision, in particular for non-zero electron masses. We present a first subset of the full two-loop calculation, namely the factorizable subset. Our calculation is based on DIANA. We reduce tensor integrals to scalar integrals in shifted (increased) dimensions and additional powers of various propagators, so-called dots-on-lines. Recurrence relations remove those dots-on-lines as well as genuine dots-on-lines (originating from mass renormalization) and reduce the dimension of the integrals to the generic d=4-2ε dimensions. The resulting master integrals have to be expanded to O(ε) to ensure proper treatment of all finite terms. (orig.)

  13. Pole Mass of the W Boson at Two-Loop Order in the Pure $\\overline {MS}$ Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Northern Illinois U.

    2015-06-03

    I provide a calculation at full two-loop order of the complex pole squared mass of the W boson in the Standard Model in the pure MS¯ renormalization scheme, with Goldstone boson mass effects resummed. This approach is an alternative to earlier ones that use on-shell or hybrid renormalization schemes. The renormalization scale dependence of the real and imaginary parts of the resulting pole mass is studied. Both deviate by about ±4  MeV from their median values as the renormalization scale is varied from 50 to 200 GeV, but the theory error is likely larger. A surprising feature of this scheme is that the two-loop QCD correction has a larger scale dependence, but a smaller magnitude, than the two-loop non-QCD correction, unless the renormalization scale is chosen very far from the top-quark mass.

  14. The two-loop sunrise integral and elliptic polylogarithms

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Luise; Weinzierl, Stefan [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz (Germany); Bogner, Christian [Institut fuer Physik, Humboldt-Universitaet zu Berlin (Germany)

    2016-07-01

    In this talk, we present a solution for the two-loop sunrise integral with arbitrary masses around two and four space-time dimensions in terms of a generalised elliptic version of the multiple polylogarithms. Furthermore we investigate the elliptic polylogarithms appearing in higher orders in the dimensional regularisation ε of the two-dimensional equal mass solution. Around two space-time dimensions the solution consists of a sum of three elliptic dilogarithms where the arguments have a nice geometric interpretation as intersection points of the integration region and an elliptic curve associated to the sunrise integral. Around four space-time dimensions the sunrise integral can be expressed with the ε{sup 0}- and ε{sup 1}-solution around two dimensions, mass derivatives thereof and simpler terms. Considering higher orders of the two-dimensional equal mass solution we find certain generalisations of the elliptic polylogarithms appearing in the ε{sup 0}- and ε{sup 1}-solutions around two and four space-time dimensions. We show that these higher order-solutions can be found by iterative integration within this class of functions.

  15. Improved two-loop beam energy stabilizer for an FN tandem accelerator

    International Nuclear Information System (INIS)

    Trainor, T.A.

    1981-01-01

    A detailed analysis of the properties of various elements in a two-loop voltage regulator for a tandem accelerator enabled design of an optimum system which reduces effective accelerating voltage noise below 100 V. Essential features of the new system are high-quality slit preamplifiers, careful attention to removal of extraneous noise sources, and proper shaping of frequency responses to maximize stable gains and ensure compatibility of the two control loops. The resultant beam energy stabilizer system is easy to operate, has well defined indicators for proper adjustment of operating parameters, and recovers reliably from beam interruptions

  16. Reduction of the N-component scalar model at the two-loop level

    International Nuclear Information System (INIS)

    Jakovac, A.

    1996-01-01

    Dimensional reduction of high temperature field theories improves IR features of their perturbative treatment. A crucial question is the following: What three-dimensional theory is representing the full system the most faithful way? A careful investigation of the induced three-dimensional counterterm structure of the finite temperature 4D O(N) symmetric scalar theory at the two-loop level leads to proposing the presence of nonlocal operators in the effective theory. A three-dimensional matching process is applied for the construction of the optimal local, superrenormalizable approximation. copyright 1996 The American Physical Society

  17. Renormalization of vacuum expectation values in spontaneously broken gauge theories: two-loop results

    International Nuclear Information System (INIS)

    Sperling, Marcus; Stöckinger, Dominik; Voigt, Alexander

    2014-01-01

    We complete the two-loop calculation of β-functions for vacuum expectation values (VEVs) in gauge theories by the missing O(g 4 )-terms. The full two-loop results are presented for generic and supersymmetric theories up to two-loop level in arbitrary R ξ -gauge. The results are obtained by means of a scalar background field, identical to our previous analysis. As a by-product, the two-loop scalar anomalous dimension for generic supersymmetric theories is presented. As an application we compute the β-functions for VEVs and tan β in the MSSM, NMSSM, and E 6 SSM

  18. Two-loop renormalization group analysis of supersymmetric SO(10) models with an intermediate scale

    International Nuclear Information System (INIS)

    Bastero-Gil, M.; Brahmachari, B.

    1996-03-01

    Two-loop evolutions of the gauge couplings in a class of intermediate scale supersymmetric SO(10) models including the effect of third generation Yukawa couplings are studied. The unification scale, the intermediate scale and the value of the unification gauge coupling in these models are calculated and the gauge boson mediated proton decay rates are estimated. In some cases the predicted proton lifetime turns out to be in the border-line of experimental limit. The predictions of the top quark mass, the mass ratio m b (m b )/m τ (m τ ) from the two-loop evolution of Yukawa couplings and the mass of the left handed neutrino via see-saw mechanism are summarized. The lower bounds on the ratio of the VEVs of the two low energy doublets (tan β) from the requirement of the perturbative unitarity of the top quark Yukawa coupling up to the grand unification scale are also presented. All the predictions have been compared with those of the one-step unified theory. (author). 33 refs, 5 figs, 1 tab

  19. Constraints on abelian extensions of the Standard Model from two-loop vacuum stability and U(1){sub B−L}

    Energy Technology Data Exchange (ETDEWEB)

    Corianò, Claudio [STAG Research Centre and Mathematical Sciences,University of Southampton, Southampton SO17 1BJ (United Kingdom); Dipartimento di Matematica e Fisica “Ennio De Giorgi' ,Università del Salento and INFN - Sezione di Lecce,Via Arnesano, 73100 Lecce (Italy); Rose, Luigi Delle; Marzo, Carlo [Dipartimento di Matematica e Fisica “Ennio De Giorgi' ,Università del Salento and INFN - Sezione di Lecce,Via Arnesano, 73100 Lecce (Italy)

    2016-02-19

    We present a renormalization group study of the scalar potential in a minimal U(1){sub B−L} extension of the Standard Model involving one extra heavier Higgs and three heavy right-handed neutrinos with family universal B-L charge assignments. We implement a type-I seesaw for the masses of the light neutrinos of the Standard Model. In particular, compared to a previous study, we perform a two-loop extension of the evolution, showing that two-loop effects are essential for the study of the stability of the scalar potential up to the Planck scale. The analysis includes the contribution of the kinetic mixing between the two abelian gauge groups, which is radiatively generated by the evolution, and the one-loop matching conditions at the electroweak scale. By requiring the stability of the potential up to the Planck mass, significant constraints on the masses of the heavy neutrinos, on the gauge couplings and the mixing in the Higgs sector are identified.

  20. Probing the desert by the two-loop renormalization-group equations

    International Nuclear Information System (INIS)

    Tanimoto, M.; Suetake, Y.; Senba, K.

    1987-01-01

    We have reexamined the study of probing the desert with fermion masses, presented by Bagger, Dimopoulos, and Masso, by using the two-loop renormalization-group equations in the framework of the SU(3) x SU(2) x U(1) model with three generations and one Higgs doublet. The blow-up energy scale of the Yukawa coupling is found to be dependent on the Higgs quartic coupling λ. If the Yukawa coupling blows up between the electroweak scale M/sub W/ and the grand unified scale M/sub X/, the Higgs potential is destabilized for small values of λ at the electroweak scale M/sub W/, and becomes strongly coupled for large values of λ at M/sub W/. It is found that the Higgs-scalar mass as well as the fermion masses are important to probe the desert

  1. Experimental Study of Flexible Plate Vibration Control by Using Two-Loop Sliding Mode Control Strategy

    Science.gov (United States)

    Yang, Jingyu; Lin, Jiahui; Liu, Yuejun; Yang, Kang; Zhou, Lanwei; Chen, Guoping

    2017-08-01

    It is well known that intelligent control theory has been used in many research fields, novel modeling method (DROMM) is used for flexible rectangular active vibration control, and then the validity of new model is confirmed by comparing finite element model with new model. In this paper, taking advantage of the dynamics of flexible rectangular plate, a two-loop sliding mode (TSM) MIMO approach is introduced for designing multiple-input multiple-output continuous vibration control system, which can overcome uncertainties, disturbances or unstable dynamics. An illustrative example is given in order to show the feasibility of the method. Numerical simulations and experiment confirm the effectiveness of the proposed TSM MIMO controller.

  2. Order α'(two-loop) equivalence of the string equations of motion and the σ-model Weyl invariance conditions

    International Nuclear Information System (INIS)

    Metsaev, R.R.; Tseytlin, A.A.

    1987-01-01

    We prove the on-shell equivalence of the order α' terms in the string effective equations (for the graviton, dilaton and the antisymmetric tensor) to the vanishing of the corresponding (two-loop) terms in the Weyl anomaly coefficients for the general bosonic σ-model. We first determine the α' term in the string effective action starting with the known expression for the 3- and 4-point string amplitudes. Then we compute the two-loop β-function in the general σ-model with the antisymmetric tensor coupling. Special emphasis is made on the renormalization scheme dependence of the β-function. Our result disagrees with the previously known one and cannot be manifestly expressed in terms of the generalized curvature for the connection with torsion. We also prove (to the order α' 2 ) that the parallelizable spaces are solutions of the string equations of motion and establish the complete 3-loop expression for the 'central charge' coefficient. (orig.)

  3. Taming the Goldstone contributions to the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P.

    2014-07-01

    The standard perturbative effective potential suffers from two related problems of principle involving the field-dependent Goldstone boson squared mass, G. First, in general G can be negative, and it actually is negative in the Standard Model; this leads to imaginary contributions to the effective potential that are not associated with a physical instability, and therefore spurious. Second, in the limit that G approaches zero, the effective potential minimization condition is logarithmically divergent already at two-loop order, and has increasingly severe power-law singularities at higher loop orders. I resolve both issues by resumming the Goldstone boson contributions to the effective potential. For the resulting resummed effective potential, the minimum value and the minimization condition that gives the vacuum expectation value are obtained in forms that do not involve G at all.

  4. MS vs. pole masses of gauge bosons II: Two-loop electroweak fermion correct

    International Nuclear Information System (INIS)

    Jegerlehner, F.; Kalmykov, M.Yu.; Veretin, O.

    2002-12-01

    We have calculated the fermion contributions to the shift of the position of the poles of the massive gauge boson propagators at two-loop order in the Standard Model. Together with the bosonic contributions calculated previously the full two-loop corrections are available. This allows us to investigate the full correction in the relationship between anti M anti S and pole masses of the vector bosons Z and W. Two-loop renormalization and the corresponding renormalization group equations are discussed. Analytical results for the master-integrals appearing in the massless fermion contributions are given. A new approach of summing multiple binomial sums has been developed. (orig.)

  5. Iterative structure within the five-particle two-loop amplitude

    International Nuclear Information System (INIS)

    Cachazo, Freddy; Spradlin, Marcus; Volovich, Anastasia

    2006-01-01

    We find an unexpected iterative structure within the two-loop five-gluon amplitude in N=4 supersymmetric Yang-Mills theory. Specifically, we show that a subset of diagrams contributing to the full amplitude, including a two-loop pentagon-box integral with nontrivial dependence on five kinematical variables, satisfies an iterative relation in terms of one-loop scalar box diagrams. The implications of this result for the possible iterative structure of the full two-loop amplitude are discussed

  6. Large momentum expansion of two-loop self-energy diagrams with arbitrary masses

    International Nuclear Information System (INIS)

    Davydychev, A.I.; Smirnov, V.A.; Tausk, J.B.

    1993-01-01

    For two-loop two-point diagrams with arbitrary masses, an algorithm to derive the asymptotic expansion at large external momentum squared is constructed. By using a general theorem on asymptotic expansions of Feynman diagrams, the coefficients of the expansion are calculated analytically. For some two-loop diagrams occurring in the Standard Model, comparison with results of numerical integration shows that our expansion works well in the region above the highest physical threshold. (orig.)

  7. New class of two-loop neutrino mass models with distinguishable phenomenology

    Science.gov (United States)

    Cao, Qing-Hong; Chen, Shao-Long; Ma, Ernest; Yan, Bin; Zhang, Dong-Ming

    2018-04-01

    We discuss a new class of neutrino mass models generated in two loops, and explore specifically three new physics scenarios: (A) doubly charged scalar, (B) dark matter, and (C) leptoquark and diquark, which are verifiable at the 14 TeV LHC Run-II. We point out how the different Higgs insertions will distinguish our two-loop topology with others if the new particles in the loop are in the simplest representations of the SM gauge group.

  8. Higgs-Boson Two-Loop Contributions to Electric Dipole Moments in the MSSM

    CERN Document Server

    Pilaftsis, Apostolos

    1999-01-01

    The complete set of Higgs-boson two-loop contributions to electric dipole moments of the electron and neutron is calculated in the minimal supersymmetric standard model. The electric dipole moments are induced by CP-violating trilinear couplings of the `CP-odd' and charged Higgs bosons to the scalar top and bottom quarks. Numerical estimates of the individual two-loop contributions to electric dipole moments are given.

  9. Landau singularities and symbology: one- and two-loop MHV amplitudes in SYM theory

    Energy Technology Data Exchange (ETDEWEB)

    Dennen, Tristan; Spradlin, Marcus; Volovich, Anastasia [Department of Physics, Brown University,Providence RI 02912 (United States)

    2016-03-14

    We apply the Landau equations, whose solutions parameterize the locus of possible branch points, to the one- and two-loop Feynman integrals relevant to MHV amplitudes in planar N=4 super-Yang-Mills theory. We then identify which of the Landau singularities appear in the symbols of the amplitudes, and which do not. We observe that all of the symbol entries in the two-loop MHV amplitudes are already present as Landau singularities of one-loop pentagon integrals.

  10. Landau singularities and symbology: one- and two-loop MHV amplitudes in SYM theory

    International Nuclear Information System (INIS)

    Dennen, Tristan; Spradlin, Marcus; Volovich, Anastasia

    2016-01-01

    We apply the Landau equations, whose solutions parameterize the locus of possible branch points, to the one- and two-loop Feynman integrals relevant to MHV amplitudes in planar N=4 super-Yang-Mills theory. We then identify which of the Landau singularities appear in the symbols of the amplitudes, and which do not. We observe that all of the symbol entries in the two-loop MHV amplitudes are already present as Landau singularities of one-loop pentagon integrals.

  11. SQED two-loop beta function in the context of Implicit regularization

    International Nuclear Information System (INIS)

    Cherchiglia, Adriano Lana; Sampaio, Marcos; Nemes, Maria Carolina

    2013-01-01

    Full text: In this work we present the state-of-art for Implicit Regularization (IReg) in the context of supersymmetric theories. IReg is a four-dimensional regularization technique in momentum space which disentangles, in a consistent way at arbitrary order, the divergencies, regularization dependent and finite parts of any Feynman amplitude. Since it does not resort to modifications on the physical space-time dimensions of the underlying quantum field theoretical model, it can be consistently applied to supersymmetric theories. First we describe the technique and present previous results for supersymmetric models: the two-loop beta function for the Wess-Zumino model (both in the component and superfield formalism); the two-loop beta function for Super Yang-Mills (in the superfield formalism using the background field technique). After, we present our calculation of the two-loop beta function for massless and massive SQED using the superfield formalism with and without resorting to the background field technique. We find that only in the second case the two-loop divergence cancels out. We argue it is due to an anomalous Jacobian under the rescaling of the fields in the path-integral which is necessary for the application of the supersymmetric background field technique. We find, however, that in both cases the two-loop coefficients of beta function are non-null. Finally we briefly discuss the anomaly puzzle in the context of our technique. (author)

  12. Systematic classification of two-loop realizations of the Weinberg operator

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, D. Aristizabal; Degee, A. [IFPA, Dep. AGO, Universite de Liege,Bat B5, Sart Tilman B-4000 Liege 1 (Belgium); Dorame, L.; Hirsch, M. [AHEP Group, Instituto de Fisica Corpuscular-C.S.I.C./Universitat de Valencia,Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2015-03-09

    We systematically analyze the d=5 Weinberg operator at 2-loop order. Using a diagrammatic approach, we identify two different interesting categories of neutrino mass models: (i) Genuine 2-loop models for which both, tree-level and 1-loop contributions, are guaranteed to be absent. And (ii) finite 2-loop diagrams, which correspond to the 1-loop generation of some particular vertex appearing in a given 1-loop neutrino mass model, thus being effectively 2-loop. From the large list of all possible 2-loop diagrams, the vast majority are infinite corrections to lower order neutrino mass models and only a moderately small number of diagrams fall into these two interesting classes. Moreover, all diagrams in class (i) are just variations of three basic diagrams, with examples discussed in the literature before. Similarly, we also show that class (ii) diagrams consists of only variations of these three plus two more basic diagrams. Finally, we show how our results can be consistently and readily used in order to construct two-loop neutrino mass models.

  13. Two-loop conformal generators for leading-twist operators in QCD

    International Nuclear Information System (INIS)

    Braun, V.M.; Strohmaier, M.; Manashov, A.N.; Hamburg Univ.; Moch, S.

    2016-01-01

    QCD evolution equations in minimal subtraction schemes have a hidden symmetry: One can construct three operators that commute with the evolution kernel and form an SL(2) algebra, i.e. they satisfy (exactly) the SL(2) commutation relations. In this paper we find explicit expressions for these operators to two-loop accuracy going over to QCD in non-integer d=4-2ε space-time dimensions at the intermediate stage. In this way conformal symmetry of QCD is restored on quantum level at the specially chosen (critical) value of the coupling, and at the same time the theory is regularized allowing one to use the standard renormalization procedure for the relevant Feynman diagrams. Quantum corrections to conformal generators in d=4-2ε effectively correspond to the conformal symmetry breaking in the physical theory in four dimensions and the SL(2) commutation relations lead to nontrivial constraints on the renormalization group equations for composite operators. This approach is valid to all orders in perturbation theory and the result includes automatically all terms that can be identified as due to a nonvanishing QCD β-function (in the physical theory in four dimensions). Our result can be used to derive three-loop evolution equations for flavor-nonsinglet quark-antiquark operators including mixing with the operators containing total derivatives. These equations govern, e.g., the scale dependence of generalized hadron parton distributions and light-cone meson distribution amplitudes.

  14. Two-loop beam and soft functions for rapidity-dependent jet vetoes

    Energy Technology Data Exchange (ETDEWEB)

    Gangal, Shireen [Theory Group, Deutsches Elektronen-Synchrotron (DESY),Notkestraße 85, D-22607 Hamburg (Germany); Gaunt, Jonathan R. [Nikhef Theory Group and VU University Amsterdam,De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands); Stahlhofen, Maximilian [PRISMA Cluster of Excellence, Institute of Physics, Johannes Gutenberg University,Staudingerweg 7, D-55128 Mainz (Germany); Tackmann, Frank J. [Theory Group, Deutsches Elektronen-Synchrotron (DESY),Notkestraße 85, D-22607 Hamburg (Germany)

    2017-02-06

    Jet vetoes play an important role in many analyses at the LHC. Traditionally, jet vetoes have been imposed using a restriction on the transverse momentum p{sub Tj} of jets. Alternatively, one can also consider jet observables for which p{sub Tj} is weighted by a smooth function of the jet rapidity y{sub j} that vanishes as |y{sub j}|→∞. Such observables are useful as they provide a natural way to impose a tight veto on central jets but a looser one at forward rapidities. We consider two such rapidity-dependent jet veto observables, T{sub Bj} and T{sub Cj}, and compute the required beam and dijet soft functions for the jet-vetoed color-singlet production cross section at two loops. At this order, clustering effects from the jet algorithm become important. The dominant contributions are computed fully analytically while corrections that are subleading in the limit of small jet radii are expressed in terms of finite numerical integrals. Our results enable the full NNLL{sup ′} resummation and are an important step towards N{sup 3}LL resummation for cross sections with a T{sub Bj} or T{sub Cj} jet veto.

  15. Two-Loop Correction to the Higgs Boson Mass in the MRSSM

    International Nuclear Information System (INIS)

    Stöckinger, Dominik; Diessner, Philip; Kotlarski, Wojciech; Kalinowski, Jan

    2015-01-01

    We present the impact of two-loop corrections on the mass of the lightest Higgs boson in the minimal R-symmetric supersymmetric standard model (MRSSM). These shift the Higgs boson mass up by typically 5 GeV or more. The dominant corrections arise from strong interactions, and from the gluon and its N=2 superpartners, the sgluon and Dirac gluino, and these corrections further increase with large Dirac gluino mass. The two-loop contributions governed purely by Yukawa couplings and the MRSSM λ, Λ parameters are smaller. We also update our earlier analysis which showed that the MRSSM can accommodate the measured Higgs and W boson masses. Including the two-loop corrections increases the parameter space where the theory prediction agrees with the measurement.

  16. Two-loop renormalization in the standard model, part I. Prolegomena

    Energy Technology Data Exchange (ETDEWEB)

    Actis, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Ferroglia, A. [Albert-Ludwigs-Univ., Freiburg (Germany). Fakultat fur Phys.]|[Zuerich Univ. (Switzerland). Inst. fuer Theoretische Physik; Passera, M. [Padua Univ. (Italy). Dipt. di Fisica]|[INFN, Sezione di Padova (Italy); Passarino, G. [Torino Univ. (Italy). Dipt. di Fisica Teorica]|[INFN, Sezione di Torino (Italy)

    2006-12-15

    In this paper the building blocks for the two-loop renormalization of the Standard Model are introduced with a comprehensive discussion of the special vertices induced in the Lagrangian by a particular diagonalization of the neutral sector and by two alternative treatments of the Higgs tadpoles. Dyson resummed propagators for the gauge bosons are derived, and two-loop Ward-Slavnov-Taylor identities are discussed. In part II, the complete set of counterterms needed for the two-loop renormalization will be derived. In part III, a renormalization scheme will be introduced, connecting the renormalized quantities to an input parameter set of (pseudo-)experimental data, critically discussing renormalization of a gauge theory with unstable particles. (orig.)

  17. N ≥ 4 Supergravity Amplitudes from Gauge Theory at Two Loops

    International Nuclear Information System (INIS)

    Boucher-Veronneau, Camille

    2012-01-01

    We present the full two-loop four-graviton amplitudes in N = 4, 5, 6 supergravity. These results were obtained using the double-copy structure of gravity, which follows from the recently conjectured color-kinematics duality in gauge theory. The two-loop four-gluon scattering amplitudes in N = 0, 1, 2 supersymmetric gauge theory are a second essential ingredient. The gravity amplitudes have the expected infrared behavior: the two-loop divergences are given in terms of the squares of the corresponding one-loop amplitudes. The finite remainders are presented in a compact form. The finite remainder for N = 8 supergravity is also presented, in a form that utilizes a pure function with a very simple symbol.

  18. Two-loop operator matrix elements for massive fermionic local twist-2 operators in QED

    International Nuclear Information System (INIS)

    Bluemlein, J.; Freitas, A. de; Universidad Simon Bolivar, Caracas; Neerven, W.L. van

    2011-11-01

    We describe the calculation of the two--loop massive operator matrix elements with massive external fermions in QED. We investigate the factorization of the O(α 2 ) initial state corrections to e + e - annihilation into a virtual boson for large cms energies s >>m 2 e into massive operator matrix elements and the massless Wilson coefficients of the Drell-Yan process adapting the color coefficients to the case of QED, as proposed by F. A. Berends et. al. (Nucl. Phys. B 297 (1988)429). Our calculations show explicitly that the representation proposed there works at one-loop order and up to terms linear in ln (s/m 2 e ) at two-loop order. However, the two-loop constant part contains a few structural terms, which have not been obtained in previous direct calculations. (orig.)

  19. Two-loop corrections for nuclear matter in the Walecka model

    International Nuclear Information System (INIS)

    Furnstahl, R.J.; Perry, R.J.; Serot, B.D.; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Physics Department and Nuclear Theory Center, Indiana University, Bloomington, Indiana 47405)

    1989-01-01

    Two-loop corrections for nuclear matter, including vacuum polarization, are calculated in the Walecka model to study the loop expansion as an approximation scheme for quantum hadrodynamics. Criteria for useful approximation schemes are discussed, and the concepts of strong and weak convergence are introduced. The two-loop corrections are evaluated first with one-loop parameters and mean fields and then by minimizing the total energy density with respect to the scalar field and refitting parameters to empirical nuclear matter saturation properties. The size and nature of the corrections indicate that the loop expansion is not convergent at two-loop order in either the strong or weak sense. Prospects for alternative approximation schemes are discussed

  20. The two-loop master integrals for qq-bar→VV

    International Nuclear Information System (INIS)

    Gehrmann, Thomas; Manteuffel, Andreas von; Tancredi, Lorenzo; Weihs, Erich

    2014-01-01

    We compute the full set of two-loop Feynman integrals appearing in massless two-loop four-point functions with two off-shell legs with the same invariant mass. These integrals allow to determine the two-loop corrections to the amplitudes for vector boson pair production at hadron colliders, qq-bar→VV, and thus to compute this process to next-to-next-to-leading order accuracy in QCD. The master integrals are derived using the method of differential equations, employing a canonical basis for the integrals. We obtain analytical results for all integrals, expressed in terms of multiple polylogarithms. We optimize our results for numerical evaluation by employing functions which are real valued for physical scattering kinematics and allow for an immediate power series expansion

  1. Color ferromagnetic vacuum states in QCD and two-loop energy densities

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Ninomiya, M.

    1979-12-01

    Two-loop energy densities of color ferromagnetic states are obtained using the β-function calculated to two-loop approximation and the exact formula for the energy density of such a state. This is used to derive bounds on the MIT bag constant correcting the previous bound in one-loop approximation. For a constant field color ferromagnetic ansatz state the bound on the QCD scale parameter Λsub(p) 3 -vacuum ansatz with two-loop and instanton correction gives Λsub(p)<= 0.16 GeV. Tt is stressed that the 'perturbative vacuum', which is identified with the inside bag state is a somewhat ill defined concept due to a path-dependence in the integral giving the energy density. (Auth.)

  2. Analytic continuation of massless two-loop four-point functions

    International Nuclear Information System (INIS)

    Gehrmann, T.; Remiddi, E.

    2002-01-01

    We describe the analytic continuation of two-loop four-point functions with one off-shell external leg and internal massless propagators from the Euclidean region of space-like 1→3 decay to Minkowskian regions relevant to all 1→3 and 2→2 reactions with one space-like or time-like off-shell external leg. Our results can be used to derive two-loop master integrals and unrenormalized matrix elements for hadronic vector-boson-plus-jet production and deep inelastic two-plus-one-jet production, from results previously obtained for three-jet production in electron-positron annihilation. (author)

  3. Two-Loop Self-Energy Correction in a Strong Coulomb Nuclear Field

    International Nuclear Information System (INIS)

    Yerokhin, V.A.; Indelicato, P.; Shabaev, V.M.

    2005-01-01

    The two-loop self-energy correction to the ground-state energy levels of hydrogen-like ions with nuclear charges Z ≥ 10 is calculated without the Zα expansion, where α is the fine-structure constant. The data obtained are compared with the results of analytical calculations within the Zα expansion; significant disagreement with the analytical results of order α 2 (Zα) 6 has been found. Extrapolation is used to obtain the most accurate value for the two-loop self-energy correction for the 1s state in hydrogen

  4. Soft radiation in heavy-particle pair production: All-order colour structure and two-loop anomalous dimension

    International Nuclear Information System (INIS)

    Beneke, M.; Falgari, P.; Schwinn, C.

    2010-01-01

    We consider the total production cross section of heavy coloured particle pairs in hadronic collisions at the production threshold. We construct a basis in colour space that diagonalizes to all orders in perturbation theory the soft function, which appears in a new factorization formula for the combined resummation of soft gluon and Coulomb gluon effects. This extends recent results on the structure of soft anomalous dimensions and allows us to determine an analytic expression for the two-loop soft anomalous dimension at threshold for all production processes of interest.

  5. On effective Kähler potential in N=2, d=3 SQED

    Directory of Open Access Journals (Sweden)

    I.L. Buchbinder

    2015-11-01

    Full Text Available We compute the two-loop effective Kähler potential in three-dimensional N=2 supersymmetric electrodynamics with Chern–Simons kinetic term for the gauge superfield. The effective action is constructed on the base of background field method with one parametric family of gauges. In such an approach, the quadratic part of quantum action mixes the gauge and matter quantum superfields yielding the complications in the computations of the loop supergraphs. To avoid this obstacle and preserve dependence on the gauge parameter we make a non-local change of quantum matter superfields after which the propagator is diagonalized, however the new vertices have appeared. We fix the suitable background and develop the efficient procedure of calculating the two-loop supergraphs with the new vertices. We compute the divergent and finite parts of the superfield effective action, find the two-loop effective Kähler potential and show that it does not depend on the gauge parameter.

  6. The width of the Δ-resonance at two loop order in baryon chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Gegelia, Jambul, E-mail: j.gegelia@fz-juelich.de [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Tbilisi State University, 0186 Tbilisi, Georgia (United States); Meißner, Ulf-G., E-mail: meissner@hiskp.uni-bonn.de [Helmholtz Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Siemens, Dmitrij, E-mail: dmitrij.siemens@rub.de [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Yao, De-Liang, E-mail: d.yao@fz-juelich.de [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-12-10

    We calculate the width of the delta resonance at leading two-loop order in baryon chiral perturbation theory. This gives a correlation between the leading pion–nucleon–delta and pion–delta couplings, which is relevant for the analysis of pion–nucleon scattering and other processes.

  7. The light-cone gauge at two loops: The scalar anomalous dimension

    International Nuclear Information System (INIS)

    Capper, D.M.; Suzuki, A.T.; Jones, D.R.T.

    1985-01-01

    We demonstrate that the light-cone gauge is a feasible tool for multi-loop computations by using it to evaluate the two-loop scalar anomalous dimension, γsup((2)), in a general gauge theory. In the special case of supersymmetry we obtain agreement with previous results which were derived using nonlight-cone techniques. (orig.)

  8. A two-loop four-gluon helicity amplitude in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, L.

    2000-01-06

    The authors present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. The construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties 4--2{epsilon} dimensions. The authors evaluate the loop integrals appearing in the amplitude through order({epsilon}{sup 0})in terms of polylogarithms.

  9. Computation of Groebner bases for two-loop propagator type integrals

    International Nuclear Information System (INIS)

    Tarasov, O.V.

    2004-01-01

    The Groebner basis technique for calculating Feynman diagrams proposed in (Acta Phys. Pol. B 29(1998) 2655) is applied to the two-loop propagator type integrals with arbitrary masses and momentum. We describe the derivation of Groebner bases for all integrals with 1PI topologies and present explicit content of the Groebner bases

  10. Computation of Groebner bases for two-loop propagator type integrals

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, O.V. [DESY Zeuthen, Theory Group, Deutsches Elektronen Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)]. E-mail: tarasov@ifh.de

    2004-11-21

    The Groebner basis technique for calculating Feynman diagrams proposed in (Acta Phys. Pol. B 29(1998) 2655) is applied to the two-loop propagator type integrals with arbitrary masses and momentum. We describe the derivation of Groebner bases for all integrals with 1PI topologies and present explicit content of the Groebner bases.

  11. Application of 't Hooft's renormalization scheme to two-loop calculations 230

    International Nuclear Information System (INIS)

    Vladimirov, A.A.

    1975-01-01

    The advantages of the Hooft scheme for asymptotic calculations in the renormalization group have been demonstrated. Two-loop calculations have been carried out in three renormalized models: in scalar electrodynamics, in a pseudoscalar Yukawa theory and in the Weiss-Zumino supersymmetrical model [ru

  12. Naturalness made easy: two-loop naturalness bounds on minimal SM extensions

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Jackson D.; Cox, Peter [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, University of Melbourne,Melbourne, 3010 (Australia)

    2017-02-24

    The main result of this paper is a collection of conservative naturalness bounds on minimal extensions of the Standard Model by (vector-like) fermionic or scalar gauge multiplets. Within, we advocate for an intuitive and physical concept of naturalness built upon the renormalisation group equations. In the effective field theory of the Standard Model plus a gauge multiplet with mass M, the low scale Higgs mass parameter is a calculable function of (MS)-bar input parameters defined at some high scale Λ{sub h}>M. If the Higgs mass is very sensitive to these input parameters, then this signifies a naturalness problem. To sensibly capture the sensitivity, it is shown how a sensitivity measure can be rigorously derived as a Bayesian model comparison, which reduces in a relevant limit to a Barbieri-Giudice-like fine-tuning measure. This measure is fully generalisable to any perturbative EFT. The interesting results of our two-loop renormalisation group study are as follows: for Λ{sub h}=Λ{sub Pl} we find “10% fine-tuning” bounds on the masses of various gauge multiplets of M

  13. Two-loop controller for maximizing performance of a grid-connected photovoltaic - fuel cell hybrid power plant

    Science.gov (United States)

    Ro, Kyoungsoo

    The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime COsb2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.

  14. Local integrand representations of all two-loop amplitudes in planar SYM

    International Nuclear Information System (INIS)

    Bourjaily, Jacob L.; Trnka, Jaroslav

    2015-01-01

    We use generalized unitarity at the integrand-level to directly construct local, manifestly dual-conformally invariant formulae for all two-loop scattering amplitudes in planar, maximally supersymmetric Yang-Mills theory (SYM). This representation separates contributions into manifestly finite and manifestly divergent terms — in a way that renders all infrared-safe observables (including ratio functions) calculable without any need for regulation. These results perfectly match the all-loop BCFW recursion relations, to which we provide a closed-form solution valid through two-loop-order. Finally, we describe and document a MATHEMATICA package which implements these results, available as part of this work’s source files on the arXiv.

  15. Resummed two-loop calculation of the disjoining pressure of a symmetric electrolyte soap film

    International Nuclear Information System (INIS)

    Dean, D.S.; Horgan, R.R.

    2004-01-01

    In this paper we consider the calculation of the disjoining pressure of a symmetric electrolytic soap film correct to two loops in perturbation theory. We show that the disjoining pressure is finite when the loop expansion is resummed using a cumulant expansion and requires no short distance cutoff in order to give a finite result. The loop expansion is resummed in terms of an expansion in g=l B /l D where l D is the Debye length and l B is the Bjerrum length. We show that there there is a nonanalytic contribution of order g ln(g). We also show that the two-loop correction is greater than the one-loop term at large film thicknesses suggesting a nonperturbative correction to the one-loop result in this limit

  16. Two-loop renormalization in the standard model, part III. Renormalization equations and their solutions

    International Nuclear Information System (INIS)

    Actis, S.; Passarino, G.

    2006-12-01

    In part I and II of this series of papers all elements have been introduced to extend, to two loops, the set of renormalization procedures which are needed in describing the properties of a spontaneously broken gauge theory. In this paper, the final step is undertaken and finite renormalization is discussed. Two-loop renormalization equations are introduced and their solutions discussed within the context of the minimal standard model of fundamental interactions. These equations relate renormalized Lagrangian parameters (couplings and masses) to some input parameter set containing physical (pseudo-)observables. Complex poles for unstable gauge and Higgs bosons are used and a consistent setup is constructed for extending the predictivity of the theory from the Lep1 Z-boson scale (or the Lep2 WW scale) to regions of interest for LHC and ILC physics. (orig.)

  17. Two-loop renormalization in the standard model, part III. Renormalization equations and their solutions

    Energy Technology Data Exchange (ETDEWEB)

    Actis, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Passarino, G. [Torino Univ. (Italy). Dipt. di Fisica Teorica; INFN, Sezione di Torino (Italy)

    2006-12-15

    In part I and II of this series of papers all elements have been introduced to extend, to two loops, the set of renormalization procedures which are needed in describing the properties of a spontaneously broken gauge theory. In this paper, the final step is undertaken and finite renormalization is discussed. Two-loop renormalization equations are introduced and their solutions discussed within the context of the minimal standard model of fundamental interactions. These equations relate renormalized Lagrangian parameters (couplings and masses) to some input parameter set containing physical (pseudo-)observables. Complex poles for unstable gauge and Higgs bosons are used and a consistent setup is constructed for extending the predictivity of the theory from the Lep1 Z-boson scale (or the Lep2 WW scale) to regions of interest for LHC and ILC physics. (orig.)

  18. Matching the $D^{6}R^{4}$ interaction at two-loops

    CERN Document Server

    D'Hoker, Eric; Pioline, Boris; Russo, Rodolfo

    2015-01-01

    The coefficient of the $D^6 {\\cal R}^4$ interaction in the low energy expansion of the two-loop four-graviton amplitude in type II superstring theory is known to be proportional to the integral of the Zhang-Kawazumi (ZK) invariant over the moduli space of genus-two Riemann surfaces. We demonstrate that the ZK invariant is an eigenfunction with eigenvalue 5 of the Laplace-Beltrami operator in the interior of moduli space. Exploiting this result, we evaluate the integral of the ZK invariant explicitly, finding agreement with the value of the two-loop $D^6 {\\cal R}^4$ interaction predicted on the basis of S-duality and supersymmetry. A review of the current understanding of the $D^{2p} {\\cal R}^4$ interactions in type II superstring theory compactified on a torus $T^d$ with $p \\leq 3$ and $d \\leq 4$ is included.

  19. Automatic calculation of massive two-loop self-energies with XLOOPS

    International Nuclear Information System (INIS)

    Franzkowski, J.

    1997-01-01

    Within the program package XLOOPS it is possible to calculate self-energies up to the two-loop level for arbitrary massive particles. The program package -written in MAPLE (Char et al., Maple V Language Reference Manual (Springer, 1991); Char et al., Maple V Library Reference Manual (Springer, 1991)) - is designed to deal with the full tensor structure of the occurring integrals. This means that applications are not restricted to those cases where the reduction to scalars via equivalence theorem is allowed. The algorithms handle two-loop integrals analytically if this is possible. For those topologies where no analytic result for the general mass case is available, the diagrams are reduced to integral representations which encounter at most at two-fold integration. These integral representations are numerically stable and can be performed easily using VEGAS (Lepage, J. Comp. Phys. 27 (1978) 192; Lepage, Cornell Univ. Preprint CLNS-80/447 (1980)). (orig.)

  20. BPS Wilson loops and Bremsstrahlung function in ABJ(M): a two loop analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Marco S. [Institut für Physik, Humboldt-Universität zu Berlin,Newtonstraße 15, 12489 Berlin (Germany); Griguolo, Luca [Dipartimento di Fisica e Scienze della Terra, Università di Parmaand INFN Gruppo Collegato di Parma,Viale G.P. Usberti 7/A, 43100 Parma (Italy); Leoni, Matias [Physics Department, FCEyN-UBA & IFIBA-CONICETCiudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Penati, Silvia [Dipartimento di Fisica, Università di Milano-Bicoccaand INFN, Sezione di Milano-Bicocca,Piazza della Scienza 3, I-20126 Milano (Italy); Seminara, Domenico [Dipartimento di Fisica, Università di Firenzeand INFN Sezione di Firenze,via G. Sansone 1, 50019 Sesto Fiorentino (Italy)

    2014-06-19

    We study a family of circular BPS Wilson loops in N=6 super Chern-Simons-matter theories, generalizing the usual 1/2-BPS circle. The scalar and fermionic couplings depend on two deformation parameters and these operators can be considered as the ABJ(M) counterpart of the DGRT latitudes defined in N=4 SYM. We perform a complete two-loop analysis of their vacuum expectation value, discuss the appearance of framing-like phases and propose a general relation with cohomologically equivalent bosonic operators. We make an all-loop proposal for computing the Bremsstrahlung function associated to the 1/2-BPS cusp in terms of these generalized Wilson loops. When applied to our two-loop result it reproduces the known expression. Finally, we comment on the generalization of this proposal to the bosonic 1/6-BPS case.

  1. Two-Loop Master Integrals for $\\gamma^{*} \\to 3$ Jets the Non-Planar Topologies

    CERN Document Server

    Gehrmann, T

    2001-01-01

    The calculation of the two-loop corrections to the three-jet production rate and to event shapes in electron--positron annihilation requires the computation of a number of two-loop four-point master integrals with one off-shell and three on-shell legs. Up to now, only those master integrals corresponding to planar topologies were known. In this paper, we compute the yet outstanding non-planar master integrals by solving differential equations in the external invariants which are fulfilled by these master integrals. We obtain the master integrals as expansions in $\\e=(4-d)/2$, where $d$ is the space-time dimension. The fully analytic results are expressed in terms of the two-dimensional harmonic polylogarithms already introduced in the evaluation of the planar topologies.

  2. Heavy-quark production in gluon fusion at two loops in QCD

    International Nuclear Information System (INIS)

    Czakon, M.

    2007-07-01

    We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed by powers of the heavy-quark mass. Our derivation uses a simple relation between massless and massive QCD scattering amplitudes as well as a direct calculation of the massive amplitude at two loops. The results presented here together with those obtained previously for quark-quark scattering form important parts of the next-to-next-to-leading order QCD corrections to heavy-quark production in hadron-hadron collisions. (orig.)

  3. Uncertainty of the two-loop RG upper bound on the Higgs mass

    International Nuclear Information System (INIS)

    Pirogov, Yu.F.; Zenin, O.V.

    2003-01-01

    A modified criterion of the SM perturbative consistency is proposed. It is based on the analytic properties of the two-loop SM running couplings. Under the criterion adopted, the Higgs mass up to 380 GeV might not give rise to strong coupling prior to the Planck scale. This means that the light Higgs boson is possibly preferred for reasons other than the SM perturbative consistency, i.e., for reasons beyond the SM

  4. Two-loop finiteness of self-energies in higher-derivative SQED3

    Directory of Open Access Journals (Sweden)

    E.A. Gallegos

    2015-09-01

    Full Text Available In the N=1 superfield formalism, two higher-derivative kinetic operators (Lee–Wick operators are implemented into the standard three dimensional supersymmetric quantum electrodynamics (SQED3 for improving its ultraviolet behavior. It is shown in particular that the ghosts associated with these Lee–Wick operators allow to remove all ultraviolet divergences in the scalar and gauge self-energies at two-loop level.

  5. Uncertainty of the two-loop RG upper bound on the Higgs mass

    International Nuclear Information System (INIS)

    Pirogov, Yu.F.; Zenin, O.V.

    2003-01-01

    A modified criterion of the standard model perturbative consistency is proposed. It is based on the analytic properties of the two-loop standard model running couplings. Under the criterion adopted, the Higgs mass up to 380 GeV might not give rise to the strong coupling prior to the Planck scale. This means that light Higgs boson is possibly preferred for reasons other than the standard model perturbative consistency, i.e., for reasons beyond the standard model [ru

  6. Two-loop QED corrections to the Altarelli-Parisi splitting functions

    Energy Technology Data Exchange (ETDEWEB)

    Florian, Daniel de [International Center for Advanced Studies (ICAS), UNSAM,Campus Miguelete, 25 de Mayo y Francia (1650) Buenos Aires (Argentina); Sborlini, Germán F.R.; Rodrigo, Germán [Instituto de Física Corpuscular, Universitat de València,Consejo Superior de Investigaciones Científicas,Parc Científic, E-46980 Paterna, Valencia (Spain)

    2016-10-11

    We compute the two-loop QED corrections to the Altarelli-Parisi (AP) splitting functions by using a deconstructive algorithmic Abelianization of the well-known NLO QCD corrections. We present explicit results for the full set of splitting kernels in a basis that includes the leptonic distribution functions that, starting from this order in the QED coupling, couple to the partonic densities. Finally, we perform a phenomenological analysis of the impact of these corrections in the splitting functions.

  7. Two-loop current–current operator contribution to the non-leptonic QCD penguin amplitude

    Directory of Open Access Journals (Sweden)

    G. Bell

    2015-11-01

    Full Text Available The computation of direct CP asymmetries in charmless B decays at next-to-next-to-leading order (NNLO in QCD is of interest to ascertain the short-distance contribution. Here we compute the two-loop penguin contractions of the current–current operators Q1,2 and provide a first estimate of NNLO CP asymmetries in penguin-dominated b→s transitions.

  8. CHIRON: a package for ChPT numerical results at two loops

    Energy Technology Data Exchange (ETDEWEB)

    Bijnens, Johan [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden)

    2015-01-01

    This document describes the package CHIRON which includes two libraries, chiron itself and jbnumlib.chiron is a set of routines useful for two-loop numerical results in chiral perturbation theory (ChPT). It includes programs for the needed one- and two-loop integrals as well as routines to deal with the ChPT parameters. The present version includes everything needed for the masses, decay constants and quark-antiquark vacuum-expectation-values. An added routine calculates consistent values for the masses and decay constants when the pion and kaon masses are varied. In addition a number of finite volume results are included: one-loop tadpole integrals, two-loop sunset integrals and the results for masses and decay constants. The numerical routine library jbnumlib contains the numerical routines used in chiron. Many are to a large extent simple C++ versions of routines in the CERNLIB numerical library. Notable exceptions are the dilogarithm and the Jacobi theta function implementations. This paper describes what is included in CHIRON v0.50. (orig.)

  9. Two-loop renormalization in the standard model, part II. Renormalization procedures and computational techniques

    Energy Technology Data Exchange (ETDEWEB)

    Actis, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Passarino, G. [Torino Univ. (Italy). Dipt. di Fisica Teorica; INFN, Sezione di Torino (Italy)

    2006-12-15

    In part I general aspects of the renormalization of a spontaneously broken gauge theory have been introduced. Here, in part II, two-loop renormalization is introduced and discussed within the context of the minimal Standard Model. Therefore, this paper deals with the transition between bare parameters and fields to renormalized ones. The full list of one- and two-loop counterterms is shown and it is proven that, by a suitable extension of the formalism already introduced at the one-loop level, two-point functions suffice in renormalizing the model. The problem of overlapping ultraviolet divergencies is analyzed and it is shown that all counterterms are local and of polynomial nature. The original program of 't Hooft and Veltman is at work. Finite parts are written in a way that allows for a fast and reliable numerical integration with all collinear logarithms extracted analytically. Finite renormalization, the transition between renormalized parameters and physical (pseudo-)observables, are discussed in part III where numerical results, e.g. for the complex poles of the unstable gauge bosons, are shown. An attempt is made to define the running of the electromagnetic coupling constant at the two-loop level. (orig.)

  10. Two-Loop Gluon to Gluon-Gluon Splitting Amplitudes in QCD

    International Nuclear Information System (INIS)

    Bern, Z.

    2004-01-01

    Splitting amplitudes are universal functions governing the collinear behavior of scattering amplitudes for massless particles. We compute the two-loop g → gg splitting amplitudes in QCD, N = 1, and N = 4 super-Yang-Mills theories, which describe the limits of two-loop n-point amplitudes where two gluon momenta become parallel. They also represent an ingredient in a direct x-space computation of DGLAP evolution kernels at next-to-next-to-leading order. To obtain the splitting amplitudes, we use the unitarity sewing method. In contrast to the usual light-cone gauge treatment, our calculation does not rely on the principal-value or Mandelstam-Leibbrandt prescriptions, even though the loop integrals contain some of the denominators typically encountered in light-cone gauge. We reduce the integrals to a set of 13 master integrals using integration-by-parts and Lorentz invariance identities. The master integrals are computed with the aid of differential equations in the splitting momentum fraction z. The ε-poles of the splitting amplitudes are consistent with a formula due to Catani for the infrared singularities of two-loop scattering amplitudes. This consistency essentially provides an inductive proof of Catani's formula, as well as an ansatz for previously-unknown 1/ε pole terms having non-trivial color structure. Finite terms in the splitting amplitudes determine the collinear behavior of finite remainders in this formula

  11. Regularization independent analysis of the origin of two loop contributions to N=1 Super Yang-Mills beta function

    Energy Technology Data Exchange (ETDEWEB)

    Fargnoli, H.G.; Sampaio, Marcos; Nemes, M.C. [Federal University of Minas Gerais, ICEx, Physics Department, P.O. Box 702, Belo Horizonte, MG (Brazil); Hiller, B. [Coimbra University, Faculty of Science and Technology, Physics Department, Center of Computational Physics, Coimbra (Portugal); Baeta Scarpelli, A.P. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Lapa, Sao Paulo (Brazil)

    2011-05-15

    We present both an ultraviolet and an infrared regularization independent analysis in a symmetry preserving framework for the N=1 Super Yang-Mills beta function to two loop order. We show explicitly that off-shell infrared divergences as well as the overall two loop ultraviolet divergence cancel out, whilst the beta function receives contributions of infrared modes. (orig.)

  12. Regularization independent analysis of the origin of two loop contributions to N=1 Super Yang-Mills beta function

    International Nuclear Information System (INIS)

    Fargnoli, H.G.; Sampaio, Marcos; Nemes, M.C.; Hiller, B.; Baeta Scarpelli, A.P.

    2011-01-01

    We present both an ultraviolet and an infrared regularization independent analysis in a symmetry preserving framework for the N=1 Super Yang-Mills beta function to two loop order. We show explicitly that off-shell infrared divergences as well as the overall two loop ultraviolet divergence cancel out, whilst the beta function receives contributions of infrared modes. (orig.)

  13. Local integrands for two-loop all-plus Yang-Mills amplitudes

    International Nuclear Information System (INIS)

    Badger, Simon; Mogull, Gustav; Peraro, Tiziano

    2016-01-01

    We express the planar five- and six-gluon two-loop Yang-Mills amplitudes with all positive helicities in compact analytic form using D-dimensional local integrands that are free of spurious singularities. The integrand is fixed from on-shell tree amplitudes in six dimensions using D-dimensional generalised unitarity cuts. The resulting expressions are shown to have manifest infrared behaviour at the integrand level. We also find simple representations of the rational terms obtained after integration in 4−2ϵ dimensions.

  14. Reggeon field theory at D = 2 in two-loop approximation

    International Nuclear Information System (INIS)

    Eremyan, Sh.S.; Nazaryan, A.E.

    1982-01-01

    A general method of constructing an explicit representation is developed for the pomeron propagator in the presence of additional parameters, such as the pomeron production threshold xi 0 , momentum transfer K vector or the intercept shift delta 0 . The method is shown to be applicable in both one-loop and two-loop approximations. The obtained general formulae allow to consider the pomeron propagator in both asymptotic region and the region of the perturbation theory applicability. Besides, they provide the smooth matching of both these regions. The observed values are calculated, and the results connected with asymptotically high energies are discussed

  15. The two-loop symbol of all multi-Regge regions

    International Nuclear Information System (INIS)

    Bargheer, Till; Schomerus, Volker; Papathanasiou, Georgios

    2015-12-01

    We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N= 4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

  16. Local integrands for two-loop all-plus Yang-Mills amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Badger, Simon; Mogull, Gustav; Peraro, Tiziano [Higgs Centre for Theoretical Physics, School of Physics and Astronomy,The University of Edinburgh, James Clerk Maxwell Building,Peter Guthrie Tait Road, Edinburgh EH9 3FD (United Kingdom)

    2016-08-09

    We express the planar five- and six-gluon two-loop Yang-Mills amplitudes with all positive helicities in compact analytic form using D-dimensional local integrands that are free of spurious singularities. The integrand is fixed from on-shell tree amplitudes in six dimensions using D-dimensional generalised unitarity cuts. The resulting expressions are shown to have manifest infrared behaviour at the integrand level. We also find simple representations of the rational terms obtained after integration in 4−2ϵ dimensions.

  17. The two-loop symbol of all multi-Regge regions

    International Nuclear Information System (INIS)

    Bargheer, Till; Papathanasiou, Georgios; Schomerus, Volker

    2016-01-01

    We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N=4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

  18. A complete two-loop, five-gluon helicity amplitude in Yang-Mills theory

    International Nuclear Information System (INIS)

    Badger, Simon; Mogull, Gustav; Ochirov, Alexander; O’Connell, Donal

    2015-01-01

    We compute the integrand of the full-colour, two-loop, five-gluon scattering amplitude in pure Yang-Mills theory with all helicities positive, using generalized unitarity cuts. Tree-level BCJ relations, satisfied by amplitudes appearing in the cuts, allow us to deduce all the necessary non-planar information for the full-colour amplitude from known planar data. We present our result in terms of irreducible numerators, with colour factors derived from the multi-peripheral colour decomposition. Finally, the leading soft divergences are checked to reproduce the expected infrared behaviour.

  19. New perturbative upper bound on MH from fermionic Higgs decays at two loops

    International Nuclear Information System (INIS)

    Durand, L.; Kniehl, B.A.; Riesselmann, K.

    1993-09-01

    We present the dominant two-loop O (G F 2 M H 4 ) electroweak corrections to the fermionic decay widths of a high-mass Higgs boson in the Standard Model. The corrections are negative and quite significant, and are larger in magnitude than the one-loop electroweak corrections for M H > or ∼400 GeV. This indicates the onset of a breakdown of perturbation theory in the Higgs sector of the Standard Model at this surprisingly low value of the Higgs boson mass. (orig.)

  20. A complete two-loop, five-gluon helicity amplitude in Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Badger, Simon; Mogull, Gustav; Ochirov, Alexander [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); O’Connell, Donal [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States)

    2015-10-09

    We compute the integrand of the full-colour, two-loop, five-gluon scattering amplitude in pure Yang-Mills theory with all helicities positive, using generalized unitarity cuts. Tree-level BCJ relations, satisfied by amplitudes appearing in the cuts, allow us to deduce all the necessary non-planar information for the full-colour amplitude from known planar data. We present our result in terms of irreducible numerators, with colour factors derived from the multi-peripheral colour decomposition. Finally, the leading soft divergences are checked to reproduce the expected infrared behaviour.

  1. The effective nuclear potential

    International Nuclear Information System (INIS)

    Skyrme, T.H.R.

    1994-01-01

    An empirical analyses is made of the mean effective internucleon potential required in the shell-model description of nuclei, allowing for the presence of many-body effects as suggested by current theory. A consistent description is found in which the effective two-body interaction acts almost entirely in even states, and the many-body effects are simulated by a repulsive three-body contact interaction. The strength of the two-body interaction is consistent with that expressed by the free scattering matrix of the two-nucleon system, and that of the three-body interaction with the 'rearrangement energy' calculated in the many-body theory. (author). 21 refs, 2 figs, 7 tabs

  2. The effective potential in the presence of several mass scales

    International Nuclear Information System (INIS)

    Casas, J.A.; Di Clemente, V.; Quiros, M.

    1999-01-01

    We consider the problem of improving the effective potential in mass independent schemes, as e.g. the MS-bar or DR-bar renormalization scheme, in the presence of an arbitrary number of fields with PHI-dependent masses M i(PHI c ) . We use the decoupling theorem at the scales μ i M i (PHI c ) such that the matching between the effective (low energy) and complete (high energy) one-loop theories contains no thresholds. We find that for any value of PHI c , there is a convenient scale μ * ≡ min i M i (PHI c ), at which the loop expansion has the best behaviour and the effective potential has the least μ-dependence. Furthermore, at this scale the effective potential coincides with the (improved) tree-level one in the effective field theory. The decoupling method is explicitly illustrated with a simple Higgs-Yukawa model, along with its relationship with other decoupling prescriptions and with proposed multi-scale renormalization approaches. The procedure leads to a nice suppression of potentially large logarithms and can be easily adapted to include higher-loop effects, which is explicitly shown at the two-loop level

  3. Testing SUSY at the LHC: Electroweak and Dark matter fine tuning at two-loop order

    CERN Document Server

    Cassel, S; Ross, G G

    2010-01-01

    In the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM) we evaluate the electroweak fine tuning measure that provides a quantitative test of supersymmetry as a solution to the hierarchy problem. Taking account of current experimental constraints we compute the fine tuning at two-loop order and determine the limits on the CMSSM parameter space and the measurements at the LHC most relevant in covering it. Without imposing the LEPII bound on the Higgs mass, it is shown that the fine tuning computed at two-loop has a minimum $\\Delta=8.8$ corresponding to a Higgs mass $m_h=114\\pm 2$ GeV. Adding the constraint that the SUSY dark matter relic density should be within present bounds we find $\\Delta=15$ corresponding to $m_h=114.7\\pm 2$ GeV and this rises to $\\Delta=17.8$ ($m_h=115.9\\pm 2$ GeV) for SUSY dark matter abundance within 3$\\sigma$ of the WMAP constraint. We extend the analysis to include the contribution of dark matter fine tuning. In this case the overall fine tuning and Higgs mas...

  4. Effective potential for non-convex potentials

    International Nuclear Information System (INIS)

    Fujimoto, Y.; O'Raifeartaigh, L.; Parravicini, G.

    1983-01-01

    It is shown that the well-known relationship between the effective potential GAMMA and the vacuum graphs μ of scalar QFT follows directly from the translational invariance of the measure, and that it holds for all values of the fields phi if, and only if, the classical potential is convex. In the non-convex case μ appears to become complex for some values of phi, but it is shown that the complexity is only apparent and is due to the failure of the loop expansion. The effective potential actually remains real and well-defined for all phi, and reduces to μ in the neighbourhood of the classical minima. A number of examples are considered, notably potentials which are spontaneously broken. In particular the mechanism by which a spontaneous breakdown may be generated by radiative corrections is re-investigated and some new insights obtained. Finally, it is shown that the renormalization group equations for the parameters may be obtained by inspection from the effective potential, and among the examples considered are SU(n) fields and supermultiplets. In particular, it is shown that for supermultiplets the effective potential is not only real but positive. (orig.)

  5. A reduced scale two loop PWR core designed with particle swarm optimization technique

    International Nuclear Information System (INIS)

    Lima Junior, Carlos A. Souza; Pereira, Claudio M.N.A; Lapa, Celso M.F.; Cunha, Joao J.; Alvim, Antonio C.M.

    2007-01-01

    Reduced scale experiments are often employed in engineering projects because they are much cheaper than real scale testing. Unfortunately, designing reduced scale thermal-hydraulic circuit or equipment, with the capability of reproducing, both accurately and simultaneously, all physical phenomena that occur in real scale and at operating conditions, is a difficult task. To solve this problem, advanced optimization techniques, such as Genetic Algorithms, have been applied. Following this research line, we have performed investigations, using the Particle Swarm Optimization (PSO) Technique, to design a reduced scale two loop Pressurized Water Reactor (PWR) core, considering 100% of nominal power and non accidental operating conditions. Obtained results show that the proposed methodology is a promising approach for forced flow reduced scale experiments. (author)

  6. Two-loop integrals for CP-even heavy quarkonium production and decays: elliptic sectors

    Science.gov (United States)

    Chen, Long-Bin; Jiang, Jun; Qiao, Cong-Feng

    2018-04-01

    By employing the differential equations, we compute analytically the elliptic sectors of two-loop master integrals appearing in the NNLO QCD corrections to CP-even heavy quarkonium exclusive production and decays, which turns out to be the last and toughest part in the relevant calculation. The integrals are found can be expressed as Goncharov polylogarithms and iterative integrals over elliptic functions. The master integrals may be applied to some other NNLO QCD calculations about heavy quarkonium exclusive production, like {γ}^{\\ast}γ \\to Q\\overline{Q} , {e}+{e}-\\to γ +Q\\overline{Q} , and H/{Z}^0\\to γ +Q\\overline{Q} , heavy quarkonium exclusive decays, and also the CP-even heavy quarkonium inclusive production and decays.

  7. A comprehensive coordinate space renormalization of quantum electrodynamics to two-loop order

    International Nuclear Information System (INIS)

    Haagensen, P.E.; Latorre, J.I.

    1993-01-01

    We develop a coordinate space renormalization of massless quantum electrodynamics using the powerful method of differential renormalization. Bare one-loop amplitudes are finite at non-coincident external points, but do not accept a Fourier transform into momentum space. The method provides a systematic procedure to obtain one-loop renormalized amplitudes with finite Fourier transforms in strictly four dimensions without the appearance of integrals or the use of a regulator. Higher loops are solved similarly by renormalizing from the inner singularities outwards to the global one. We compute all one- and two-loop 1PI diagrams, run renormalization group equations on them. and check Ward identities. The method furthermore allows us to discern a particular pattern of renormalization under which certain amplitudes are seen not to contain higher-loop leading logarithms. We finally present the computation of the chiral triangle showing that differential renormalization emerges as a natural scheme to tackle γ 5 problems

  8. Small-threshold behaviour of two-loop self-energy diagrams: two-particle thresholds

    International Nuclear Information System (INIS)

    Berends, F.A.; Davydychev, A.I.; Moskovskij Gosudarstvennyj Univ., Moscow; Smirnov, V.A.; Moskovskij Gosudarstvennyj Univ., Moscow

    1996-01-01

    The behaviour of two-loop two-point diagrams at non-zero thresholds corresponding to two-particle cuts is analyzed. The masses involved in a cut and the external momentum are assumed to be small as compared to some of the other masses of the diagram. By employing general formulae of asymptotic expansions of Feynman diagrams in momenta and masses, we construct an algorithm to derive analytic approximations to the diagrams. In such a way, we calculate several first coefficients of the expansion. Since no conditions on relative values of the small masses and the external momentum are imposed, the threshold irregularities are described analytically. Numerical examples, using diagrams occurring in the standard model, illustrate the convergence of the expansion below the first large threshold. (orig.)

  9. TLTA/6431, Two-Loop-Test-Apparatus, BWR/6 Simulator, Small-Break LOCA

    International Nuclear Information System (INIS)

    1992-01-01

    1 - Description of test facility: The Two-Loop-Test-Apparatus (TLTA) is a 1:624 volume scaled BWR/6 simulator. It was the predecessor of the better-scaled FIST facility. The facility is capable of full BWR system pressure and has a simulated core with a full size 8 x 8, full power single bundle of indirect electrically heated rods. All major BWR systems are simulated including lower plenum, guide tube, core region (bundle and bypass), upper plenum, steam separator, steam dome, annular downcomer, recirculation loops and ECC injection systems. The fundamental scaling consideration was to achieve real-time response. A number of the scaling compromises present in TLTA were corrected in the FIST configuration. These compromises include a number of regional volumes and component elevations. 2 - Description of test: 64.45 sqcm small break LOCA with activation of the full emergency core cooling system, but without activation of the automatic decompression system

  10. Evolution of the pion wave function in the scalar /phi/63 model: two-loop calculation

    International Nuclear Information System (INIS)

    Mikhailov, S.V.; Radyushkin, A.V.

    1986-01-01

    The authors study the structure of the contributions that violate the multiplicative renormalizability of the conformal operators in the model based on the /phi/ 6 3 theory in space-time of six dimensions. This theory has a number of features in common with QCD in four dimensions. The basic propositions are presented and the key elements of the calculation are demonstrated. The connection between the kernels for exclusive and inclusive processes are discused and the structure of the two-loop evolution kernel V(x,y) and the solution of the evolution equation are discussed. Main conclusions are formulated and the results of the calculations for concrete diagrams are deferred to in Appendix A. Formulas for the transition from the exclusive to the inclusive kernels are presented in Appendix B

  11. An effective potential for heavy quark antiquark bound system

    International Nuclear Information System (INIS)

    Barik, B.K.; Deo, B.B.

    1985-01-01

    A heavy quark antiquark potential is suggested connecting asymptotic freedom and quark confinement in a unified way. The α g (q 2 ) calculated using Borel summation technique with three loop agrees with the two loop β-function up to g 2 /4π ∼ 1.1 but changes appreciably after g 2 /4π = 1.5. The potential so derived satisfactorily explains the c overlined c and b overlined b spectrum. (author)

  12. Evidence for two-loop interaction from IRIS and SDO observations of penumbral brightenings

    Science.gov (United States)

    Alissandrakis, C. E.; Koukras, A.; Patsourakos, S.; Nindos, A.

    2017-07-01

    Aims: We investigate small scale energy release events which can provide clues on the heating mechanism of the solar corona. Methods: We analyzed spectral and imaging data from the Interface Region Imaging Spectrograph (IRIS), images from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatoty (SDO), and magnetograms from the Helioseismic and Magnetic Imager (HMI) aboard SDO. Results: We report observations of small flaring loops in the penumbra of a large sunspot on July 19, 2013. Our main event consisted of a loop spanning 15'', from the umbral-penumbral boundary to an opposite polarity region outside the penumbra. It lasted approximately 10 min with a two minute impulsive peak and was observed in all AIA/SDO channels, while the IRIS slit was located near its penumbral footpoint. Mass motions with an apparent velocity of 100 km s-1 were detected beyond the brightening, starting in the rise phase of the impulsive peak; these were apparently associated with a higher-lying loop. We interpret these motions in terms of two-loop interaction. IRIS spectra in both the C II and Si iv lines showed very extended wings, up to about 400 km s-1, first in the blue (upflows) and subsequently in the red wing. In addition to the strong lines, emission was detected in the weak lines of Cl I, O I and C I, as well as in the Mg II triplet lines. Absorption features in the profiles of the C II doublet, the Si iv doublet and the Mg II h and k lines indicate the existence of material with a lower source function between the brightening and the observer. We attribute this absorption to the higher loop and this adds further credibility to the two-loop interaction hypothesis. Tilts were detected in the absorption spectra, as well as in the spectra of Cl I, O I, and C I lines, possibly indicating rotational motions from the untwisting of magnetic flux tubes. Conclusions: We conclude that the absorption features in the C II, Si iv and Mg II profiles originate in a higher

  13. Experimental tests for the Babu-Zee two-loop model of Majorana neutrino masses

    International Nuclear Information System (INIS)

    Sierra, Diego Aristizabal; Hirsch, Martin

    2006-01-01

    The smallness of the observed neutrino masses might have a radiative origin. Here we revisit a specific two-loop model of neutrino mass, independently proposed by Babu and Zee. We point out that current constraints from neutrino data can be used to derive strict lower limits on the branching ratio of flavour changing charged lepton decays, such as μ→eγ. Non-observation of Br(μ→eγ) at the level of 10 -13 would rule out singly charged scalar masses smaller than 590 GeV (5.04 TeV) in case of normal (inverse) neutrino mass hierarchy. Conversely, decay branching ratios of the non-standard scalars of the model can be fixed by the measured neutrino angles (and mass scale). Thus, if the scalars of the model are light enough to be produced at the LHC or ILC, measuring their decay properties would serve as a direct test of the model as the origin of neutrino masses

  14. Experimental tests for the Babu-Zee two-loop model of Majorana neutrino masses

    International Nuclear Information System (INIS)

    Aristizabal, D.

    2006-01-01

    Abstract: The smallness of the observed neutrino masses might have a radiative origin. Here we revisit a specific two-loop model of neutrino mass, independently proposed by Babu and Zee. We point out that current constraints from neutrino data can be used to derive strict lower limits on the branching ratio of flavour changing charged lepton decays, such as μ → e γ. Non-observation of Br(μ → e γ) at the level of 10 -13 would rule out singly charged scalar masses smaller than 590 GeV (5.04 TeV) in case of normal (inverse) neutrino mass hierarchy. Conversely, decay branching ratios of the non-standard scalars of the model can be fixed by the measured neutrino angles (and mass scale). Thus, if the scalars of the model are light enough to be produced at the LHC or ILC, measuring their decay properties would serve as a direct test of the model as the origin of neutrino masses. (author)

  15. (Quasi)Elastic Electron-Muon Large-Angle Scattering to a Two-Loop Approximation: Vertex Contributions

    CERN Document Server

    Bytev, V V; Shaikhatdenov, B G

    2002-01-01

    We consider a process of quasielastic e\\mu large-angle scattering at high energies with radiative corrections up to a two-loop level. The lowest order radiative correction arising both from one-loop virtual photon emission and a real soft emission are presented to a power accuracy. Two-loop level corrections are supposed to be of three gauge-invariant classes. One of them, so-called vertex contribution, is given in logarithmic approximation. Relation with the renormalization group approach is discussed.

  16. (Quasi)Elastic Electron-Muon Large-Angle Scattering to a Two-Loop Approximation Vertex Contributions

    CERN Document Server

    Bytev, V V; Shaikhatdenov, B G

    2002-01-01

    We consider a process of quasielastic e\\mu large-angle scattering at high energies with radiative corrections up to a two-loop level. The lowest order radiative correction arising both from one-loop virtual photon emission and a real soft emission are presented to a power accuracy. Two-loop level corrections are supposed to be of three gauge-invariant classes. One of them, so-called vertex contribution, is given in logarithmic approximation. Relation with the renormalization group approach is discussed.

  17. BOKASUN: a fast and precise numerical program to calculate the Master Integrals of the two-loop sunrise diagrams

    OpenAIRE

    Caffo, Michele; Czyz, Henryk; Gunia, Michal; Remiddi, Ettore

    2008-01-01

    We present the program BOKASUN for fast and precise evaluation of the Master Integrals of the two-loop self-mass sunrise diagram for arbitrary values of the internal masses and the external four-momentum. We use a combination of two methods: a Bernoulli accelerated series expansion and a Runge-Kutta numerical solution of a system of linear differential equations.

  18. Effective potential and spontaneous symmetry breaking in the noncommutative φ6 model

    International Nuclear Information System (INIS)

    Barbosa, G.D.

    2004-01-01

    We study the conditions for spontaneous symmetry breaking of the (2+1)-dimensional noncommutative φ 6 model in the small-θ limit. In this regime, considering the model as a cutoff theory, it is reasonable to assume translational invariance as a property of the vacuum state and study the conditions for spontaneous symmetry breaking by an effective potential analysis. An investigation of up to the two-loop level reveals that noncommutative effects can modify drastically the shape of the effective potential. Under reasonable conditions, the nonplanar sector of the theory can become dominant and induce symmetry breaking for values of the mass and coupling constants not reached by the commutative counterpart

  19. Effective potentials for twisted fields

    International Nuclear Information System (INIS)

    Banach, R.

    1981-01-01

    Minus the density of the effective action, evaluated at the lowest eigenfunction of the (space-time) derivative part of the second (functional) derivative of the classical action, is proposed as a generalised definition of the effective potential, applicable to twisted as well as untwisted sectors of a field theory. The proposal is corroborated by several specific calculations in the twisted sector, namely phi 4 theory (real and complex) and wrong-sign-Gordon theory, in an Einstein cylinder, where the exact integrability of the static solutions confirms the effective potential predictions. Both models exhibit a phase transition, which the effective potential locates, and the one-loop quantum shift in the critical radius is computed for the real phi 4 model, being a universal result. Topological mass generation at the classical level is pointed out, and the exactness of the classical effective potential approximation for complex phi 4 is discussed. (author)

  20. Comment on the prediction of two-loop standard chiral perturbation theory for low-energy ππ scattering

    International Nuclear Information System (INIS)

    Girlanda, L.; Moussallam, B.; Stern, J.; Knecht, M.

    1997-03-01

    Four of the six parameters defining the two-loop ππ scattering amplitude have been determined using Roy dispersion relations. Combining this information with the Standard χ PT expressions, the threshold parameters, low-energy phases and the O(p 4 ) constants l 1 r , l 2 r are obtained. The result reproduces the correct D-waves but it is incompatible with existing Standard χ PT analyses of K 14 form factors beyond one loop. (author)

  1. Two-loop O(ααs) corrections to the on-shell fermion propagator in the standard model

    International Nuclear Information System (INIS)

    Eiras, Dolors; Steinhauser, Matthias

    2006-01-01

    In this paper we consider mixed two-loop electroweak corrections to the top quark propagator in the Standard Model. In particular, we compute the on-shell renormalization constant for the mass and wave function, which constitute building blocks for many physical processes. The results are expressed in terms of master integrals. For the latter practical approximations are derived. In the case of the mass renormalization constant we find agreement with the results in the literature

  2. Effective potential for heavy quark antiquark bound system

    Energy Technology Data Exchange (ETDEWEB)

    Barik, B K; Deo, B B

    1985-12-01

    A heavy quark antiquark potential is suggested connecting asymptotic freedom and quark confinement in a unified way. The ..cap alpha../sub g/(q/sup 2/) calculated using Borel summation technique with three loop agrees with the two loop ..beta..-function up to g/sup 2//4..pi.. -- 1.1 but changes appreciably after g/sup 2//4..pi.. = 1.5. The potential so derived satisfactorily explains the c overlined c and b overlined b spectrum. 13 refs., 4 figures, 3 tables.

  3. Evaluation of two loop-mediated isothermal amplification methods for the detection of Salmonella Enteritidis and Listeria monocytogenes in artificially contaminated ready-to-eat fresh products

    Directory of Open Access Journals (Sweden)

    Angeliki Birmpa

    2015-08-01

    Full Text Available In the present study, the effectiveness of two loop-mediated isothermal amplification (LAMP assays was evaluated. Samples of romaine lettuce, strawberries, cherry tomatoes, green onions and sour berries were inoculated with known dilutions (100-108 CFU/g of produce of S. Enteritidis and L. monocytogenes. With LAMP assay, pathogens can be detected in less than 60 min. The limits of detection of S. Enteritidis and L. monocytogenes depended on the food sample tested and on the presence of enrichment step. After enrichment steps, all food samples were found positive even at low initial pathogen levels. The developed LAMP, assays, are expected to become a valuable, robust, innovative, powerful, cheap and fast monitoring tool, which can be extensively used for routine analysis, and screening of contaminated foods by the food industry and the Public Food Health Authorities.

  4. Two loop virtual corrections to b → (d, s)l{sup +}l{sup -} and c → ul{sup +}l{sup -} for arbitrary momentum transfer

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Stefan de [TU Dortmund, Fakultaet fuer Physik, Dortmund (Germany)

    2017-11-15

    Non-factorizable two loop corrections to heavy to light flavor changing neutral current transitions due to matrix elements of current-current operators are calculated analytically for arbitrary momentum transfer. This extends previous work on b → (d, s)l{sup +}l{sup -} transitions. New results for c → ul{sup +}l{sup -} transitions are presented. Recent work on polylogarithms is used for the master integrals. For b → sl{sup +}l{sup -} transitions, the corrections are most significant for the imaginary parts of the effective Wilson coefficients in the large hadronic recoil range. Analytical results and ready-to-use fitted results for a specific set of parameters are provided. (orig.)

  5. Scaling Regimes in the Model of Passive Scalar Advected by the Turbulent Velocity Field with Finite Correlation Time. Influence of Helicity in Two-Loop Approximation

    CERN Document Server

    Chkhetiani, O G; Jurcisinova, E; Jurcisin, M; Mazzino, A; Repasan, M

    2005-01-01

    The advection of a passive scalar quantity by incompressible helical turbulent flow has been investigated in the framework of an extended Kraichnan model. Statistical fluctuations of the velocity field are assumed to have the Gaussian distribution with zero mean and defined noise with finite-time correlation. Actual calculations have been done up to two-loop approximation in the framework of the field-theoretic renormalization group approach. It turned out that the space parity violation (helicity) of a stochastic environment does not affect anomalous scaling which is the peculiar attribute of a corresponding model without helicity. However, stability of asymptotic regimes, where anomalous scaling takes place, and the effective diffusivity strongly depend on the amount of helicity.

  6. Two-loop self-energy in the Lamb shift of the ground and excited states of hydrogenlike ions

    Science.gov (United States)

    Yerokhin, V. A.

    2018-05-01

    The two-loop self-energy correction to the Lamb shift of hydrogenlike ions is calculated for the 1 s , 2 s , and 2 p1 /2 states and nuclear charge numbers Z =30 -100 . The calculation is performed to all orders in the nuclear binding strength parameter Z α . As compared to previous calculations of this correction, numerical accuracy is improved by an order of magnitude and the region of the nuclear charges is extended. An analysis of the Z dependence of the obtained results demonstrates their consistency with the known Z α -expansion coefficients.

  7. Schouten identities for Feynman graph amplitudes; The Master Integrals for the two-loop massive sunrise graph

    International Nuclear Information System (INIS)

    Remiddi, Ettore; Tancredi, Lorenzo

    2014-01-01

    A new class of identities for Feynman graph amplitudes, dubbed Schouten identities, valid at fixed integer value of the dimension d is proposed. The identities are then used in the case of the two-loop sunrise graph with arbitrary masses for recovering the second-order differential equation for the scalar amplitude in d=2 dimensions, as well as a chained set of equations for all the coefficients of the expansions in (d−2). The shift from d≈2 to d≈4 dimensions is then discussed

  8. Two-loop top and bottom Yukawa corrections to the Higgs-boson masses in the complex MSSM

    Science.gov (United States)

    Paßehr, Sebastian; Weiglein, Georg

    2018-03-01

    Results for the two-loop corrections to the Higgs-boson masses of the MSSM with complex parameters of O{( α _t^2+α _tα _b+α _b^2) } from the Yukawa sector in the gauge-less limit are presented. The corresponding self-energies and their renormalization have been obtained in the Feynman-diagrammatic approach. The impact of the new contributions on the Higgs spectrum is investigated. Furthermore, a comparison with an existing result in the limit of the MSSM with real parameters is carried out. The new results will be included in the public code FeynHiggs.

  9. A new deformation of W-infinity and applications to the two-loop WZNW and conformal affine Toda models

    International Nuclear Information System (INIS)

    Aratyn, H.; Ferreira, L.A.; Gomes, J.F.; Zimerman, A.H.

    1992-01-01

    We constructed a center less W-infinity type of algebra in terms of a generator of a center less Virasoro algebra and an Abelian spin-1 current. This algebra conventionally emerges in the study of pseudo-differential operators on a circle or alternatively within KP hierarchy with Watanabe's bracket. Construction used here is based on a special deformation of the algebra w ∞ of area preserving diffeomorphisms of a 2-manifold. We show that this deformation technique applies to the two-loop WZNW and conformal affine Toda models, establishing henceforth W ∞ invariance of these models. (author)

  10. Two-loop top and bottom Yukawa corrections to the Higgs-boson masses in the complex MSSM

    International Nuclear Information System (INIS)

    Passehr, Sebastian; Weiglein, Georg

    2017-05-01

    Results for the two-loop corrections to the Higgs-boson masses of the MSSM with complex parameters of O(α 2 t +α t α b +α 2 b ) from the Yukawa sector in the gauge-less limit are presented. The corresponding self-energies and their renormalization have been obtained in the Feynman-diagrammatic approach. The impact of the new contributions on the Higgs spectrum is investigated. Furthermore, a comparison with an existing result in the limit of the MSSM with real parameters is carried out. The new results will be included in the public code FeynHiggs.

  11. Analytic result for the two-loop six-point NMHV amplitude in N=4 super Yang-Mills theory

    CERN Document Server

    Dixon, Lance J.; Henn, Johannes M.

    2012-01-01

    We provide a simple analytic formula for the two-loop six-point ratio function of planar N = 4 super Yang-Mills theory. This result extends the analytic knowledge of multi-loop six-point amplitudes beyond those with maximal helicity violation. We make a natural ansatz for the symbols of the relevant functions appearing in the two-loop amplitude, and impose various consistency conditions, including symmetry, the absence of spurious poles, the correct collinear behaviour, and agreement with the operator product expansion for light-like (super) Wilson loops. This information reduces the ansatz to a small number of relatively simple functions. In order to fix these parameters uniquely, we utilize an explicit representation of the amplitude in terms of loop integrals that can be evaluated analytically in various kinematic limits. The final compact analytic result is expressed in terms of classical polylogarithms, whose arguments are rational functions of the dual conformal cross-ratios, plus precisely two function...

  12. Two-loop amplitudes and master integrals for the production of a Higgs boson via a massive quark and a scalar-quark loop

    CERN Document Server

    Anastasiou, C; Bucherer, S; Daleo, A; Kunszt, Zoltán; Anastasiou, Charalampos; Beerli, Stefan; Bucherer, Stefan; Daleo, Alejandro; Kunszt, Zoltan

    2007-01-01

    We compute all two-loop master integrals which are required for the evaluation of next-to-leading order QCD corrections in Higgs boson production via gluon fusion. Many two-loop amplitudes for 2 -> 1 processes in the Standard Model and beyond can be expressed in terms of these integrals using automated reduction techniques. These integrals also form a subset of the master integrals for more complicated 2 -> 2 amplitudes with massive propagators in the loops. As a first application, we evaluate the two-loop amplitude for Higgs boson production in gluon fusion via a massive quark. Our result is the first independent check of the calculation of Spira, Djouadi, Graudenz and Zerwas. We also present for the first time the two-loop amplitude for gg -> h via a massive squark.

  13. The effective crystal field potential

    CERN Document Server

    Mulak, J

    2000-01-01

    As it results from the very nature of things, the spherical symmetry of the surrounding of a site in a crystal lattice or an atom in a molecule can never occur. Therefore, the eigenfunctions and eigenvalues of any bound ion or atom have to differ from those of spherically symmetric respective free ions. In this way, the most simplified concept of the crystal field effect or ligand field effect in the case of individual molecules can be introduced. The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, ar...

  14. Numerical integration of massive two-loop Mellin-Barnes integrals in Minkowskian regions

    International Nuclear Information System (INIS)

    Dubovyk, Ievgen

    2016-07-01

    Mellin-Barnes (MB) techniques applied to integrals emerging in particle physics perturbative calculations are summarized. New versions of AMBRE packages which construct planar and nonplanar MB representations are shortly discussed. The numerical package MBnumerics.m is presented for the first time which is able to calculate with a high precision multidimensional MB integrals in Minkowskian regions. Examples are given for massive vertex integrals which include threshold effects and several scale parameters.

  15. Numerical integration of massive two-loop Mellin-Barnes integrals in Minkowskian regions

    Energy Technology Data Exchange (ETDEWEB)

    Dubovyk, Ievgen [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Gluza, Janusz [Uniwersytet Slaski, Katowice (Poland). Inst. Fizyki; Riemann, Tord [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uniwersytet Slaski, Katowice (Poland). Inst. Fizyki; Usovitsch, Johann [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2016-07-15

    Mellin-Barnes (MB) techniques applied to integrals emerging in particle physics perturbative calculations are summarized. New versions of AMBRE packages which construct planar and nonplanar MB representations are shortly discussed. The numerical package MBnumerics.m is presented for the first time which is able to calculate with a high precision multidimensional MB integrals in Minkowskian regions. Examples are given for massive vertex integrals which include threshold effects and several scale parameters.

  16. Two-loop planar master integrals for the production of off-shell vector bosons in hadron collisions

    International Nuclear Information System (INIS)

    Henn, Johannes M.; Melnikov, Kirill; Smirnov, Vladimir A.

    2014-01-01

    We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals in this class are the two-loop four-point functions where two external lines are on the light-cone and two other external lines have different invariant masses. We compute these and other relevant integrals analytically using differential equations in external kinematic variables and express our results in terms of Goncharov polylogarithms. The case of two equal off-shellnesses, recently considered in ref. http://dx.doi.org/10.1007/JHEP08(2013)070, appears as a particular case of our general solution

  17. Analytic two-loop results for self-energy- and vertex-type diagrams with one non-zero mass

    International Nuclear Information System (INIS)

    Fleischer, J.; Kotikov, A.V.; Veretin, O.L.

    1999-01-01

    For a large class of two-loop self-energy- and vertex-type diagrams with only one non-zero mass (m) and the vertices also with only one non-zero external momentum squared (q 2 ) the first few expansion coefficients are calculated by the large mass expansion. This allows us to 'guess' the general structure of these coefficients and to verify them in terms of certain classes of 'basis elements', which are essentially harmonic sums. Since for this case with only one non-zero mass the large mass expansion and the Taylor series in terms of q 2 are identical, this approach yields analytic expressions of the Taylor coefficients, from which the diagram can be easily evaluated numerically in a large domain of the complex q 2 -plane by well known methods. It is also possible to sum the Taylor series and present the results in terms of polylogarithms

  18. Dominant two-loop electroweak corrections to the hadroproduction of a pseudoscalar Higgs boson and its photonic decay

    International Nuclear Information System (INIS)

    Brod, J.; Kniehl, B.A.

    2008-01-01

    We present the dominant two-loop electroweak corrections to the partial decay widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A 0 , with mass M A 0 W , in the two-Higgs-doublet model for low to intermediate values of the ratio tan β=v 2 /v 1 of the vacuum expectation values. They apply as they stand to the production cross sections in hadronic and two-photon collisions, at the Tevatron, the LHC, and a future photon collider. The appearance of three γ 5 matrices in closed fermion loops requires special care in the dimensional regularization of ultraviolet divergences. The corrections are negative and amount to several percent, so that they fully compensate or partly screen the enhancement due to QCD corrections. (orig.)

  19. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhen, E-mail: liu-zhen@sjtu.edu.cn; Gu, Pei-Hong, E-mail: peihong.gu@sjtu.edu.cn

    2017-02-15

    We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  20. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    2017-02-01

    Full Text Available We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  1. Two-loop top and bottom Yukawa corrections to the Higgs-boson masses in the complex MSSM

    Energy Technology Data Exchange (ETDEWEB)

    Passehr, Sebastian; Weiglein, Georg

    2017-05-15

    Results for the two-loop corrections to the Higgs-boson masses of the MSSM with complex parameters of O(α{sup 2}{sub t}+α{sub t}α{sub b}+α{sup 2}{sub b}) from the Yukawa sector in the gauge-less limit are presented. The corresponding self-energies and their renormalization have been obtained in the Feynman-diagrammatic approach. The impact of the new contributions on the Higgs spectrum is investigated. Furthermore, a comparison with an existing result in the limit of the MSSM with real parameters is carried out. The new results will be included in the public code FeynHiggs.

  2. Application of code scaling, applicability and uncertainty methodology to large break LOCA analysis of two loop PWR

    International Nuclear Information System (INIS)

    Mavko, B.; Stritar, A.; Prosek, A.

    1993-01-01

    In NED 119, No. 1 (May 1990) a series of six papers published by a Technical Program Group presented a new methodology for the safety evaluation of emergency core cooling systems in nuclear power plants. This paper describes the application of that new methodology to the LB LOCA analysis of the two loop Westinghouse power plant. Results of the original work were used wherever possible, so that the analysis was finished in less than one man year of work. Steam generator plugging level and safety injection flow rate were used as additional uncertainty parameters, which had not been used in the original work. The computer code RELAP5/MOD2 was used. Response surface was generated by the regression analysis and by the artificial neural network like Optimal Statistical Estimator method. Results were compared also to the analytical calculation. (orig.)

  3. Two-loop superstrings IV The cosmological constant and modular forms

    International Nuclear Information System (INIS)

    D'Hoker, E.; Phong, D.H.

    2002-01-01

    The slice-independent gauge-fixed superstring chiral measure in genus 2 derived in the earlier papers of this series for each spin structure is evaluated explicitly in terms of theta-constants. The slice-independence allows an arbitrary choice of superghost insertion points q 1 ,q 2 in the explicit evaluation, and the most effective one turns out to be the split gauge defined by S δ (q 1 ,q 2 )=0. This results in expressions involving bilinear theta-constants M. The final formula in terms of only theta-constants follows from new identities between M and theta-constants which may be interesting in their own right. The action of the modular group Sp(4,Z) is worked out explicitly for the contribution of each spin structure to the superstring chiral measure. It is found that there is a unique choice of relative phases which insures the modular invariance of the full chiral superstring measure, and hence a unique way of implementing the GSO projection for even spin structure. The resulting cosmological constant vanishes, not by a Riemann identity, but rather by the genus 2 identity expressing any modular form of weight 8 as the square of a modular form of weight 4. The degeneration limits for the contribution of each spin structure are determined, and the divergences, before the GSO projection, are found to be the ones expected on physical grounds

  4. Convexity of the effective potential

    International Nuclear Information System (INIS)

    Haymaker, R.W.; Perez-Mercader, J.

    1978-01-01

    The effective potential V(phi) in field theories is a convex function of phi. V(lambda phi 1 + (1 - lambda)phi 2 ) less than or equal to lambdaV(phi 1 ) + (1 - lambda)V(phi 2 ), 0 less than or equal to lambda less than or equal to 1, all phi 1 , phi 2 . A linear interpolation of V(phi) is always larger than or equal to V(phi). There are numerous examples in the tree approximation and in perturbation theory for which this is not the case, the most notorious example being the double dip potential. More complete solutions may or may not show this property automatically. However, a non-convex V(phi) simply indicates that an unstable vacuum state was used in implementing the definition of V(phi). A strict definition will instruct one to replace V(phi) with its linear interpolation in such a way as to make it convex. (Alternatively one can just as well take the view that V(phi) is undefined in these domains.) In this note, attention is called to a very simple argument for convexity based on a construction described by H. Callen in his classic book Thermodynamics

  5. Status of effective potential calculations

    CERN Document Server

    Quiros, M.

    1995-01-01

    We review various effective potential methods which have been useful to compute the Higgs mass spectrum and couplings of the minimal supersymmetric standard model. We compare results where all-loop next-to-leading-log corrections are resummed by the renormalization group, with those where just the leading-log corrections are kept. Pole masses are obtained from running masses by addition of convenient self-energy diagrams. Approximate analytical expressions are worked out, providing an excellent approximation to the numerical results which include all next-to-leading-log terms. An appropriate treatment of squark decoupling allows to consider large values of the stop and/or sbottom mixing parameters and thus fix a reliable upper bound on the mass of the lightest CP-even Higgs boson mass.

  6. BOKASUN: A fast and precise numerical program to calculate the Master Integrals of the two-loop sunrise diagrams

    Science.gov (United States)

    Caffo, Michele; Czyż, Henryk; Gunia, Michał; Remiddi, Ettore

    2009-03-01

    We present the program BOKASUN for fast and precise evaluation of the Master Integrals of the two-loop self-mass sunrise diagram for arbitrary values of the internal masses and the external four-momentum. We use a combination of two methods: a Bernoulli accelerated series expansion and a Runge-Kutta numerical solution of a system of linear differential equations. Program summaryProgram title: BOKASUN Catalogue identifier: AECG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 9404 No. of bytes in distributed program, including test data, etc.: 104 123 Distribution format: tar.gz Programming language: FORTRAN77 Computer: Any computer with a Fortran compiler accepting FORTRAN77 standard. Tested on various PC's with LINUX Operating system: LINUX RAM: 120 kbytes Classification: 4.4 Nature of problem: Any integral arising in the evaluation of the two-loop sunrise Feynman diagram can be expressed in terms of a given set of Master Integrals, which should be calculated numerically. The program provides a fast and precise evaluation method of the Master Integrals for arbitrary (but not vanishing) masses and arbitrary value of the external momentum. Solution method: The integrals depend on three internal masses and the external momentum squared p. The method is a combination of an accelerated expansion in 1/p in its (pretty large!) region of fast convergence and of a Runge-Kutta numerical solution of a system of linear differential equations. Running time: To obtain 4 Master Integrals on PC with 2 GHz processor it takes 3 μs for series expansion with pre-calculated coefficients, 80 μs for series expansion without pre-calculated coefficients, from a few seconds up to a few minutes for Runge-Kutta method (depending

  7. Two-loop planar master integrals for Higgs →3 partons with full heavy-quark mass dependence

    International Nuclear Information System (INIS)

    Bonciani, Roberto; Duca, Vittorio Del; Frellesvig, Hjalte; Henn, Johannes M.; Moriello, Francesco; Smirnov, Vladimir A.

    2016-01-01

    We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs→3 partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to fully inclusive Higgs production and to the NLO corrections to Higgs production in association with a jet, in the full theory. The computation is performed using the differential equations method. Whenever possible, a basis of master integrals that are pure functions of uniform weight is used. The result is expressed in terms of one-fold integrals of polylogarithms and elementary functions up to transcendental weight four. Two integral sectors are expressed in terms of elliptic integrals. We show that by introducing a one-dimensional parametrization of the integrals the relevant second order differential equation can be readily solved, and the solution can be expressed to all orders of the dimensional regularization parameter in terms of iterated integrals over elliptic kernels. We express the result for the elliptic sectors in terms of two and three-fold iterated integrals, which we find suitable for numerical evaluations. This is the first time that four-point multiscale Feynman integrals have been computed in a fully analytic way in terms of elliptic integrals.

  8. Two-loop master integrals for the mixed EW-QCD virtual corrections to Drell-Yan scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bonciani, Roberto [' ' La Sapienza' ' Univ., Rome (Italy). Dipt. di Fisica; INFN Sezione Roma (Italy); Di Vita, Stefano [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mastrolia, Pierpaolo [Max-Planck-Institut fuer Physik, Muenchen (Germany); Padova Univ. (Italy). Dipt. di Fisica e Astronomia; INFN Sezione di Padova (Italy); Schubert, Ulrich [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2016-04-15

    We present the calculation of the master integrals needed for the two-loop QCD x EW corrections to q+ anti q → l{sup -}+l{sup +} and q+ anti q{sup '} → l{sup -}+ anti ν, for massless external particles. We treat W and Z bosons as degenerate in mass. We identify three types of diagrams, according to the presence of massive internal lines: the no-mass type, the one-mass type, and the two-mass type, where all massive propagators, when occurring, contain the same mass value. We find a basis of 49 master integrals and evaluate them with the method of the differential equations. The Magnus exponential is employed to choose a set of master integrals that obeys a canonical system of differential equations. Boundary conditions are found either by matching the solutions onto simpler integrals in special kinematic configurations, or by requiring the regularity of the solution at pseudo-thresholds. The canonical master integrals are finally given as Taylor series around d=4 space-time dimensions, up to order four, with coefficients given in terms of iterated integrals, respectively up to weight four.

  9. Two-loop planar master integrals for Higgs →3 partons with full heavy-quark mass dependence

    Energy Technology Data Exchange (ETDEWEB)

    Bonciani, Roberto [Dipartimento di Fisica, Sapienza - Università di Roma,Piazzale Aldo Moro 5, 00185, Rome (Italy); INFN Sezione di Roma, Piazzale Aldo Moro 2, 00185, Rome (Italy); Duca, Vittorio Del [ETH Zurich, Institut fur theoretische Physik, Wolfgang-Paulistr. 27, 8093, Zurich (Switzerland); INFN Laboratori Nazionali di Frascati, 00044 Frascati, Roma (Italy); Frellesvig, Hjalte [Institute of Nuclear and Particle Physics, NCSR Demokritos, Agia Paraskevi, 15310 (Greece); Henn, Johannes M. [PRISMA Cluster of Excellence, Johannes Gutenberg University, 55099 Mainz (Germany); Moriello, Francesco [Dipartimento di Fisica, Sapienza - Università di Roma,Piazzale Aldo Moro 5, 00185, Rome (Italy); INFN Sezione di Roma, Piazzale Aldo Moro 2, 00185, Rome (Italy); ETH Zurich, Institut fur theoretische Physik, Wolfgang-Paulistr. 27, 8093, Zurich (Switzerland); Smirnov, Vladimir A. [Skobeltsyn Institute of Nuclear Physics of Moscow State University, 119991 Moscow (Russian Federation)

    2016-12-19

    We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs→3 partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to fully inclusive Higgs production and to the NLO corrections to Higgs production in association with a jet, in the full theory. The computation is performed using the differential equations method. Whenever possible, a basis of master integrals that are pure functions of uniform weight is used. The result is expressed in terms of one-fold integrals of polylogarithms and elementary functions up to transcendental weight four. Two integral sectors are expressed in terms of elliptic integrals. We show that by introducing a one-dimensional parametrization of the integrals the relevant second order differential equation can be readily solved, and the solution can be expressed to all orders of the dimensional regularization parameter in terms of iterated integrals over elliptic kernels. We express the result for the elliptic sectors in terms of two and three-fold iterated integrals, which we find suitable for numerical evaluations. This is the first time that four-point multiscale Feynman integrals have been computed in a fully analytic way in terms of elliptic integrals.

  10. Effective potential models for hadrons

    International Nuclear Information System (INIS)

    Lucha, W.

    1995-12-01

    The aim of these lectures is to give a self-contained introduction to nonrelativistic potential models, to their formulation as well as to their possible applications. At the price of some lack of (in a mathematical sense) rigorous derivations, we try to give a feeling and understanding for the simplest conceivable method to extract the explicit form of the forces acting between quarks from the interplay between experimental observations and theoretical considerations. According to this spirit, we demonstrate, in detail, how to obtain the underlying Hamiltonian and how to determine the Lorentz structure of the quark-(anti-)quark interaction potential from well-established experimental facts. (author)

  11. On the two-loop corrections to the pole mass of the B quark in the gaugeless limit of the MSSM

    International Nuclear Information System (INIS)

    Bednyakov, A.V.; Kazakov, D.I.; )

    2007-01-01

    The result for the two-loop corrections to the pole mass of the b quark in the gaugeless limit of the MSSM is presented. In this limit it is assumed that the contribution from the electroweak gauge interactions is small. The result presented here differs from one obtained earlier, especially in some particular regions of the MSSM parameter space [ru

  12. Two-loop massive fermionic operator matrix elements and intial state QED corrections to e{sup +}e{sup -}{yields}{gamma}{sup *}/Z{sup *}

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Universidad Simon Bolivar, Caracas (Venezuela). Dept. de Fisica; Neerven, W. van [Leiden Univ. (Netherlands). Lorentz Institute

    2008-12-15

    We describe the calculation of the two-loop massive operator matrix elements for massive external fermions. These matrix elements are needed for the calculation of the O({alpha}{sup 2}) initial state radiative corrections to e{sup +}e{sup -} annihilation into a neutral virtual gauge boson, based on the renormalization group technique. (orig.)

  13. Effective pair potentials for spherical nanoparticles

    International Nuclear Information System (INIS)

    Van Zon, Ramses

    2009-01-01

    An effective description for rigid spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, as can occur for some forms of the pair potentials, the effective potential generally has non-analytic points. It is shown that for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Even when only non-overlapping situations are possible, the auxiliary potentials facilitate the formulation of the effective potentials. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered and shown to be related to those for solid nanoparticles. For hollow nanoparticles overlap is more physical, since this covers the case of a smaller particle embedded in a larger, hollow nanoparticle. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London–van der Waals, Morse, Buckingham, and Lennard-Jones potentials. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure

  14. Symmetry-improved 2PI approach to the Goldstone-boson IR problem of the SM effective potential

    Directory of Open Access Journals (Sweden)

    Apostolos Pilaftsis

    2016-05-01

    Full Text Available The effective potential of the Standard Model (SM, from three loop order and higher, suffers from infrared (IR divergences arising from quantum effects due to massless would-be Goldstone bosons associated with the longitudinal polarizations of the W± and Z bosons. Such IR pathologies also hinder accurate evaluation of the two-loop threshold corrections to electroweak quantities, such as the vacuum expectation value of the Higgs field. However, these divergences are an artifact of perturbation theory, and therefore need to be consistently resummed in order to obtain an IR-safe effective potential. The so-called Two-Particle-Irreducible (2PI effective action provides a rigorous framework to consistently perform such resummations, without the need to resort to ad hoc subtractions or running into the risk of over-counting contributions. By considering the recently proposed symmetry-improved 2PI formalism, we address the problem of the Goldstone-boson IR divergences of the SM effective potential in the gaugeless limit of the theory. In the same limit, we evaluate the IR-safe symmetry-improved 2PI effective potential, after taking into account quantum loops of chiral fermions, as well as the renormalization of spurious custodially breaking effects triggered by fermionic Yukawa interactions. Finally, we compare our results with those obtained with other methods presented in the literature.

  15. Standard Model Effective Potential from Trace Anomalies

    Directory of Open Access Journals (Sweden)

    Renata Jora

    2018-01-01

    Full Text Available By analogy with the low energy QCD effective linear sigma model, we construct a standard model effective potential based entirely on the requirement that the tree level and quantum level trace anomalies must be satisfied. We discuss a particular realization of this potential in connection with the Higgs boson mass and Higgs boson effective couplings to two photons and two gluons. We find that this kind of potential may describe well the known phenomenology of the Higgs boson.

  16. Potential Therapeutic Effects of Psilocybin.

    Science.gov (United States)

    Johnson, Matthew W; Griffiths, Roland R

    2017-07-01

    Psilocybin and other 5-hydroxytryptamine 2A agonist classic psychedelics have been used for centuries as sacraments within indigenous cultures. In the mid-twentieth century they were a focus within psychiatry as both probes of brain function and experimental therapeutics. By the late 1960s and early 1970s these scientific inquires fell out of favor because classic psychedelics were being used outside of medical research and in association with the emerging counter culture. However, in the twenty-first century, scientific interest in classic psychedelics has returned and grown as a result of several promising studies, validating earlier research. Here, we review therapeutic research on psilocybin, the classic psychedelic that has been the focus of most recent research. For mood and anxiety disorders, three controlled trials have suggested that psilocybin may decrease symptoms of depression and anxiety in the context of cancer-related psychiatric distress for at least 6 months following a single acute administration. A small, open-label study in patients with treatment-resistant depression showed reductions in depression and anxiety symptoms 3 months after two acute doses. For addiction, small, open-label pilot studies have shown promising success rates for both tobacco and alcohol addiction. Safety data from these various trials, which involve careful screening, preparation, monitoring, and follow-up, indicate the absence of severe drug-related adverse reactions. Modest drug-related adverse effects at the time of medication administration are readily managed. US federal funding has yet to support therapeutic psilocybin research, although such support will be important to thoroughly investigate efficacy, safety, and therapeutic mechanisms.

  17. Two-loop ghost-antighost condensation for SU(2) Yang-Mills theories in the maximal abelian gauge

    International Nuclear Information System (INIS)

    Fazio, A.R.

    2004-01-01

    In the framework of the formalism of Cornwall et.al. for composite operators I study the ghost-antighost condensation in SU(2) Yang-Mills theories quantized in the Maximal Abelian Gauge and derive analytically a condensating effective potential at two ghost loops. I find that in this approximation the one-loop pairing ghost-antighost is not destroyed and no mass is generated if the ansatz for the propagator suggested by the tree level Hubbard-Stratonovich transformations is used

  18. Dysfunctional methods and the effective potential

    International Nuclear Information System (INIS)

    Dannenberg, A.; California Univ., Berkeley

    1988-01-01

    The effective potential is a useful and much-studied object. It is known to be both real and convex, but a perturbative calculation often gives a complex and nonconvex result. In this letter we address the apparent conflict between perturbation theory and the convexity of the effective potential. (orig.)

  19. Superfield tadpole method for SUSY effective potential

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1983-01-01

    Superfield formulation of Weinberg's tadpole method to compute the effective potential in supersymmetric theories is illustrated by considering the general renormalizable action involving only chiral scalar superfields. Unconstrained superfield potentials are introduced to simplify the ''effective'' superfield propagator which is derived in a compact form. (orig.)

  20. Two loop O(αsGFmt2) corrections to the fermionic decay rates of the standard-model Higgs boson

    International Nuclear Information System (INIS)

    Kniehl, B.A.

    1994-05-01

    Low- and intermediate mass Higgs bosons decay preferably into fermion pairs. The one-loop electroweak corrections to the respective decay rates are dominated by a flavour-independent term of O(G F m t 2 ). We calculate the two-loop gluon correction to this term. It turns out that this correction screens the leading high-m t behaviour of the one-loop result by roughly 10%. We also present the two-loop QCD correction to the contribution induced by a pair of fourth-generation quarks with arbitrary masses. As expected, the inclusion of the QCD correction considerably reduces the renormalization-scheme dependence of the prediction. (orig.)

  1. Effective potentials in gauge field theories

    International Nuclear Information System (INIS)

    Caldas, P.S.S.; Fleming, H.; Garcia, R.L.

    An elementary and very efficient method for computing the effective potential of any theory containing scalar bosons is described. Examples include massless scalar electrodynamics and Yang-Mills theories [pt

  2. Potential environmental effects of controlled thermonuclear reactors

    International Nuclear Information System (INIS)

    Young, J.R.; Gore, B.F.

    1976-01-01

    The following topics are discussed: (1) the fusion reaction, (2) approach to the environmental analysis, (3) the reference CTR, (4) CTR environmental effects, (5) CTR accident potential, and (6) the advanced CTR

  3. A single quark effective potential model

    International Nuclear Information System (INIS)

    Bodmann, B.E.J.; Vasconcellos, C.A.Z.

    1994-01-01

    In the present work we construct a radial spherical symmetric single quark potential model for the nucleon, consistent with asymptotic freedom and confinement. The quark mass enters as potential parameter and that way induces indirectly an isospin dependence in the interaction. As a consequence, a contribution to the negative charge square radius of the neutron arises an an effect of the quark core, which simulates an isospin symmetry breaking effect in the nucleon due to strong interaction. (author)

  4. Hyperspherical effective interaction for nonlocal potentials

    International Nuclear Information System (INIS)

    Barnea, N.; Leidemann, W.; Orlandini, G.

    2010-01-01

    The effective interaction hyperspherical-harmonics method, formulated for local forces, is generalized to accommodate nonlocal interactions. As for local potentials this formulation retains the separation of the hyper-radial part leading solely to a hyperspherical effective interaction. By applying the method to study ground-state properties of 4 He with a modern effective-field-theory nucleon-nucleon potential model (Idaho-N3LO), one finds a substantial acceleration in the convergence rate of the hyperspherical-harmonics series. Also studied are the binding energies of the six-body nuclei 6 He and 6 Li with the JISP16 nuclear force. Again an excellent convergence is observed.

  5. Effective potential and chiral symmetry breaking

    International Nuclear Information System (INIS)

    Hochberg, David

    2010-01-01

    The nonequilibrium effective potential is calculated for the Frank model of spontaneous mirror-symmetry breaking in chemistry in which external noise is introduced to account for random environmental effects. The well-mixed limit, corresponding to negligible diffusion, and the case of diffusion in two space dimensions are studied in detail. White noise has a disordering effect in the former case, whereas in the latter case a phase transition occurs for external noise exceeding a critical intensity which racemizes the system.

  6. Relations between effective potentials in different dimensions

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1983-01-01

    Using dimensional regularization, the one-loop approximation for the effective potential (finite temperature) is computed as an analytic function of the number of dimensions. It is shown that a simple relation exists between potentials for different dimensions. This relation reduces to a simple derivative when these numbers differ by two units. The limit of zero temperature is calculated and also the finite temperature corrections are given. (Author) [pt

  7. Potential effects of gallium on cladding materials

    International Nuclear Information System (INIS)

    Wilson, D.F.; Beahm, E.C.; Besmann, T.M.; DeVan, J.H.; DiStefano, J.R.; Gat, U.; Greene, S.R.; Rittenhouse, P.L.; Worley, B.A.

    1997-10-01

    This paper identifies and examines issues concerning the incorporation of gallium in weapons derived plutonium in light water reactor (LWR) MOX fuels. Particular attention is given to the more likely effects of the gallium on the behavior of the cladding material. The chemistry of weapons grade (WG) MOX, including possible consequences of gallium within plutonium agglomerates, was assessed. Based on the calculated oxidation potentials of MOX fuel, the effect that gallium may have on reactions involving fission products and possible impact on cladding performance were postulated. Gallium transport mechanisms are discussed. With an understanding of oxidation potentials and assumptions of mechanisms for gallium transport, possible effects of gallium on corrosion of cladding were evaluated. Potential and unresolved issues and suggested research and development (R and D) required to provide missing information are presented

  8. Maximum potential preventive effect of hip protectors

    NARCIS (Netherlands)

    van Schoor, N.M.; Smit, J.H.; Bouter, L.M.; Veenings, B.; Asma, G.B.; Lips, P.T.A.M.

    2007-01-01

    OBJECTIVES: To estimate the maximum potential preventive effect of hip protectors in older persons living in the community or homes for the elderly. DESIGN: Observational cohort study. SETTING: Emergency departments in the Netherlands. PARTICIPANTS: Hip fracture patients aged 70 and older who

  9. Improving the gaussian effective potential: quantum mechanics

    International Nuclear Information System (INIS)

    Eboli, O.J.P.; Thomaz, M.T.; Lemos, N.A.

    1990-08-01

    In order to gain intuition for variational problems in field theory, we analyze variationally the quantum-mechanical anharmonic oscillator [(V(x)sup(k) - sub(2) x sup(2) + sup(λ) - sub(4) λ sup(4)]. Special attention is paid to improvements to the Gaussian effective potential. (author)

  10. Two-Loop Quark Self-Energy in a New Formalism; 2, Renormalization of the Quark Propagator in the Light-Cone Gauge

    CERN Document Server

    Leibbrandt, George; Leibbrandt, George; Williams, Jimmy D.

    2000-01-01

    The complete two-loop correction to the quark propagator, consisting of the spider, rainbow, gluon bubble and quark bubble diagrams, is evaluated in the noncovariant light-cone gauge (lcg). (The overlapping self-energy diagram had already been computed.) The chief technical tools include the powerful matrix integration technique, the n^*-prescription for the spurious poles of 1/qn, and the detailed analysis of the boundary singularities in five- and six-dimensional parameter space. It is shown that the total divergent contribution to the two-loop correction Sigma_2 contains both covariant and noncovariant components, and is a local function of the external momentum p, even off the mass-shell, as all nonlocal divergent terms cancel exactly. Consequently, both the quark mass and field renormalizations are local. The structure of Sigma_2 implies a quark mass counterterm of the form $\\delta m (lcg) = m\\tilde\\alpha_s C_F(3+\\tilde\\alpha_sW) + {\\rm O} (\\tilde\\alpha_s^3)$, the dimensional regulator epsilon, and on th...

  11. Two-loop quark self-energy in a new formalism; 2, Renormalization of the quark propagator in the light-cone gauge

    CERN Document Server

    Leibbrandt, G

    2000-01-01

    For pt.I see ibid., vol.440, p.537-602, 1995. The complete two-loop correction to the quark propagator, consisting of the spider, rainbow, gluon bubble and quark bubble diagrams, is evaluated in the non-covariant light-cone gauge (LCG), n.A/sup a/(x)=0, n/sup 2/=0. (The overlapping self-energy diagram had already been computed.) The chief technical tools include the powerful matrix integration technique, the n*/sub mu /-prescription for the spurious poles of (q.n)/sup -1/, and the detailed analysis of the boundary singularities in five- and six-dimensional parameter space. It is shown that the total divergent contribution to the two-loop correction Sigma /sub 2/ contains both covariant and non-covariant components, and is a local function of the external momentum p, even off the mass-shell, as all non-local divergent terms cancel exactly. Consequently, both the quark mass and field renormalizations are local. The structure of Sigma /sub 2/ implies a quark mass counterterm of the form delta m(LCG)=m alpha /sub...

  12. Global fits of the two-loop renormalized Two-Higgs-Doublet model with soft Z 2 breaking

    Science.gov (United States)

    Chowdhury, Debtosh; Eberhardt, Otto

    2015-11-01

    We determine the next-to-leading order renormalization group equations for the Two-Higgs-Doublet model with a softly broken Z 2 symmetry and CP conservation in the scalar potential. We use them to identify the parameter regions which are stable up to the Planck scale and find that in this case the quartic couplings of the Higgs potential cannot be larger than 1 in magnitude and that the absolute values of the S-matrix eigenvalues cannot exceed 2 .5 at the electroweak symmetry breaking scale. Interpreting the 125 GeV resonance as the light CP -even Higgs eigenstate, we combine stability constraints, electroweak precision and flavour observables with the latest ATLAS and CMS data on Higgs signal strengths and heavy Higgs searches in global parameter fits to all four types of Z 2 symmetry. We quantify the maximal deviations from the alignment limit and find that in type II and Y the mass of the heavy CP -even ( CP -odd) scalar cannot be smaller than 340 GeV (360 GeV). Also, we pinpoint the physical parameter regions compatible with a stable scalar potential up to the Planck scale. Motivated by the question how natural a Higgs mass of 125 GeV can be in the context of a Two-Higgs-Doublet model, we also address the hierarchy problem and find that the Two-Higgs-Doublet model does not offer a perturbative solution to it beyond 5 TeV.

  13. Taming infrared divergences in the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Elias-Miro, J. [IFAE, Univ. Autonoma de Barcelona (Spain); Universitat Autonoma de Barcelona (Spain). Dept. de Fisica; Espinosa, J.R. [IFAE, Univ. Autonoma de Barcelona (Spain); ICREA, Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain); Konstandin, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2014-06-15

    The Higgs effective potential in the Standard Model (SM), calculated perturbatively, generically suffers from infrared (IR) divergences when the (field-dependent) tree-level mass of the Goldstone bosons goes to zero. Such divergences can affect both the potential and its first derivative and become worse with increasing loop order. In this paper we show that these IR divergences are spurious, we perform a simple resummation of all IR-problematic terms known (up to three loops) and explain how to extend the resummation to cure all such divergences to any order. The method is of general applicability and would work in scenarios other than the SM. Our discussion has some bearing on a scenario recently proposed as a mechanism for gauge mediation of scale breaking in the ultraviolet, in which it is claimed that the low-energy Higgs potential is non-standard. We argue that all non-decoupling effects from the heavy sector can be absorbed in the renormalization of low-energy parameters leading to a SM-like effective theory.

  14. Taming infrared divergences in the effective potential

    International Nuclear Information System (INIS)

    Elias-Miro, J.; Konstandin, T.

    2014-06-01

    The Higgs effective potential in the Standard Model (SM), calculated perturbatively, generically suffers from infrared (IR) divergences when the (field-dependent) tree-level mass of the Goldstone bosons goes to zero. Such divergences can affect both the potential and its first derivative and become worse with increasing loop order. In this paper we show that these IR divergences are spurious, we perform a simple resummation of all IR-problematic terms known (up to three loops) and explain how to extend the resummation to cure all such divergences to any order. The method is of general applicability and would work in scenarios other than the SM. Our discussion has some bearing on a scenario recently proposed as a mechanism for gauge mediation of scale breaking in the ultraviolet, in which it is claimed that the low-energy Higgs potential is non-standard. We argue that all non-decoupling effects from the heavy sector can be absorbed in the renormalization of low-energy parameters leading to a SM-like effective theory.

  15. Garlic: a review of potential therapeutic effects

    Science.gov (United States)

    Bayan, Leyla; Koulivand, Peir Hossain; Gorji, Ali

    2014-01-01

    Throughout history, many different cultures have recognized the potential use of garlic for prevention and treatment of different diseases. Recent studies support the effects of garlic and its extracts in a wide range of applications. These studies raised the possibility of revival of garlic therapeutic values in different diseases. Different compounds in garlic are thought to reduce the risk for cardiovascular diseases, have anti-tumor and anti-microbial effects, and show benefit on high blood glucose concentration. However, the exact mechanism of all ingredients and their long-term effects are not fully understood. Further studies are needed to elucidate the pathophysiological mechanisms of action of garlic as well as its efficacy and safety in treatment of various diseases. PMID:25050296

  16. Could piracetam potentiate behavioural effects of psychostimulants?

    Science.gov (United States)

    Slais, Karel; Machalova, Alena; Landa, Leos; Vrskova, Dagmar; Sulcova, Alexandra

    2012-08-01

    Press and internet reports mention abuse of nootropic drug piracetam (PIR) in combination with psychostimulants methamphetamine (MET) or 4-methylenedioxymethamphetamine (MDMA). These combinations are believed to produce more profound desirable effects, while decreasing hangover. However, there is a lack of valid experimental studies on such drug-drug interactions in the scientific literature available. Our hypothesis proposes that a functional interaction exists between PIR and amphetamine psychostimulants (MET and MDMA) which can potentiate psychostimulant behavioural effects. Our hypothesis is supported by the results of our pilot experiment testing acute effects of drugs given to mice intraperitoneally (Vehicle, n=12; MET 2.5mg/kg, n=10; MDMA 2.5mg/kg, n=11; PIR 300 mg/kg, n=12; PIR+MET, n=12; PIR+MDMA, n=11) in the Open Field Test (Actitrack, Panlab, Spain). PIR given alone caused no significant changes in mouse locomotor/exploratory behaviour, whereas the same dose combined with either MET or MDMA significantly enhanced their stimulatory effects. Different possible neurobiological mechanism underlying drug-drug interaction of PIR with MET or MDMA are discussed, as modulation of dopaminergic, glutamatergic or cholinergic brain systems. However, the interaction with membrane phospholipids seems as the most plausible mechanism explaining PIR action on activities of neurotransmitter systems. Despite that our behavioural experiment cannot serve for explanation of the pharmacological mechanisms of these functional interactions, it shows that PIR effects can increase behavioural stimulation of amphetamine drugs. Thus, the reported combining of PIR with MET or MDMA by human abusers is not perhaps a coincidental phenomenon and may be based on existing PIR potential to intensify acute psychostimulant effects of these drugs of abuse. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. On the effective quark potential in baryons

    International Nuclear Information System (INIS)

    Gromes, D.

    1977-01-01

    The splitting of the non-strange members of the first excited level [70,1 - ] 1 of baryon resonances is analysed. The spin-dependent forces (spin-spin, spin-orbit, tensor) are supposed to arise from the Coulomb term due to one-gluon exchange, from the long-range linearly rising part of the potential, and from additional 'hard-core' spin-spin terms which may be generated by higher-order graphs contributing to the qq kernel. For the long range part it is assumed either that it comes from a superposition of a vector and a scalar kernel of the form epsilon(γsup(μ) X γsub(μ) X 1) + (1 - epsilon)(1 X 1 X 1) (+ permutations), or, alternatively, that it arises from a vector exchange with an anomalous moment kappa in the quark-gluon vertex. Values of epsilon approximately 0 or kappa approximately -1 turn out to be favoured. The strong coupling constant and the slope of the linear potential come out in the correct order of magnitude. Very large hard-core spin-spin terms are needed. This fact makes the determination of the effective potential from the underlying theory of quantum chromodynamics as well as the phenomenological analysis of the observed spectra rather problematic. (Auth.)

  18. Potential effects of organizational uncertainty on safety

    International Nuclear Information System (INIS)

    Durbin, N.E.; Lekberg, A.; Melber, B.D.

    2001-12-01

    When organizations face significant change - reorganization, mergers, acquisitions, down sizing, plant closures or decommissioning - both the organizations and the workers in those organizations experience significant uncertainty about the future. This uncertainty affects the organization and the people working in the organization - adversely affecting morale, reducing concentration on safe operations, and resulting in the loss of key staff. Hence, organizations, particularly those using high risk technologies, which are facing significant change need to consider and plan for the effects of organizational uncertainty on safety - as well as planning for other consequences of change - technical, economic, emotional, and productivity related. This paper reviews some of what is known about the effects of uncertainty on organizations and individuals, discusses the potential consequences of uncertainty on organizational and individual behavior, and presents some of the implications for safety professionals

  19. Potential effects of organizational uncertainty on safety

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, N.E. [MPD Consulting Group, Kirkland, WA (United States); Lekberg, A. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Melber, B.D. [Melber Consulting, Seattle WA (United States)

    2001-12-01

    When organizations face significant change - reorganization, mergers, acquisitions, down sizing, plant closures or decommissioning - both the organizations and the workers in those organizations experience significant uncertainty about the future. This uncertainty affects the organization and the people working in the organization - adversely affecting morale, reducing concentration on safe operations, and resulting in the loss of key staff. Hence, organizations, particularly those using high risk technologies, which are facing significant change need to consider and plan for the effects of organizational uncertainty on safety - as well as planning for other consequences of change - technical, economic, emotional, and productivity related. This paper reviews some of what is known about the effects of uncertainty on organizations and individuals, discusses the potential consequences of uncertainty on organizational and individual behavior, and presents some of the implications for safety professionals.

  20. Potential effects of sulforaphane to fight obesity.

    Science.gov (United States)

    Martins, Tânia; Colaço, Bruno; Venâncio, Carlos; Pires, Maria J; Oliveira, Paula A; Rosa, Eduardo; Antunes, Luís M

    2018-06-01

    Obesity is linked to the onset of many diseases such as diabetes mellitus, cardiovascular diseases and cancer, among others. The prevalence of obesity nearly doubled worldwide between 1980 and 2014. Simultaneously, in the last decade, the effects of sulforaphane as a potential treatment for obesity have been investigated, with promising results. Fruits and vegetables and their processed agri-food co-products are good sources of natural health-promoting compounds. Brassica crops are among the most produced crops in the world and are a good source of glucoraphanin, which, following hydrolysis, releases sulforaphane. The Brassicaceae family generates large amounts of co-products with no intended use, causing negative economic and environmental impact. Valorization of these co-products could be achieved through their exploitation for the extraction of bioactive compounds such as sulforaphane. However, the extraction process still needs further improvement for its economic feasibility. This article reviews the potential effects of sulforaphane in the treatment of obesity, linked to the relevance of giving Brassica co-products added value, which is of key importance for the competitiveness of farmers and the agri-food industry. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  1. Effect of relative humidity on solar potential

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol

    2005-01-01

    In this study, the effect of relative humidity on solar potential is investigated using artificial neural-networks. Two different models are used to train the neural networks. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine-duration, and mean temperature) are used in the input layer of the network (Model 1). But, relative humidity values are added to one network in model (Model 2). In other words, the only difference between the models is relative humidity. New formulae based on meteorological and geographical data, have been developed to determine the solar energy potential in Turkey using the networks' weights for both models. Scaled conjugate gradient (SCG) and Levenberg-Marquardt (LM) learning algorithms and a logistic sigmoid transfer-function were used in the network. The best approach was obtained by the SCG algorithm with nine neurons for both models. Meteorological data for the four years, 2000-2003, for 18 cities (Artvin, Cesme, Bozkurt, Malkara, Florya, Tosya, Kizilcahamam, Yenisehir, Edremit, Gediz, Kangal, Solhan, Ergani, Selcuk, Milas, Seydisehir, Siverek and Kilis) spread over Turkey have been used as data in order to train the neural network. Solar radiation is in output layer. One month for each city was used as test data, and these months have not been used for training. The maximum mean absolute percentage errors (MAPEs) for Tosya are 2.770394% and 2.8597% for Models 1 and 2, respectively. The minimum MAPEs for Seydisehir are 1.055205% and 1.041% with R 2 (99.9862%, 99.9842%) for Models 1 and 2, respectively, in the SCG algorithm with nine neurons. The best value of R 2 for Models 1 and 2 are for Seydisehir. The minimum value of R 2 for Model 1 is 99.8855% for Tosya, and the value for Model 2 is 99.9001% for Yenisehir. Results show that the humidity has only a negligible effect upon the prediction of solar potential using artificial neural-networks

  2. Effective core potential methods for the lanthanides

    International Nuclear Information System (INIS)

    Cundari, T.R.; Stevens, W.J.

    1993-01-01

    In this paper a complete set of effective core potentials (ECPs) and valence basis sets for the lanthanides (Ce to Lu) are derived. These ECPs are consistent not only within the lanthanide series, but also with the third-row transition metals which bracket them. A 46-electron core was chosen to provide the best compromise between computational savings and chemical accuracy. Thus, the 5s and 5p are included as ''outer'' core while all lower energy atomic orbitals (AOs) are replaced with the ECP. Generator states were chosen from the most chemically relevant +3 and +2 oxidation states. The results of atomic calculations indicate that the greatest error vs highly accurate numerical potential/large, even-tempered basis set calculations results from replacement of the large, even-tempered basis sets with more compact representations. However, the agreement among atomic calculations remains excellent with both basis set sizes, for a variety of spin and oxidation states, with a significant savings in time for the optimized valence basis set. It is expected that the compact representation of the ECPs and valence basis sets will eventually encourage their use by computational chemists to further explore the bonding and reactivity of lanthanide complexes

  3. Improved effective potential by nonlinear canonical transformations

    International Nuclear Information System (INIS)

    Ritschel, U.

    1990-01-01

    We generalize the familiar gaussian-effective-potential formalism to a class of non-gaussian trial states. With the help of exact nonlinear canonical transformations, expectation values can be calculated analytically and in closed form. A detailed description of our method, particularly for quadratic and cubic transformations, and of the related renormalization procedure is given. Applications to φ 4 -models in various dimensionalities are treated. We find the expected critical behaviour in two space-time dimensions. In three and four dimensions we observe instabilities which go back the incompleteness of the gaussian-based renormalization. In the appendices it is shown that the quadratic transformation leads to a coherent state in a certain limiting case, and the generalization to systems at finite temperature is performed. (orig.)

  4. Nanomaterials potentiating standard chemotherapy drugs' effect

    Science.gov (United States)

    Kazantsev, S. O.; Korovin, M. S.

    2017-09-01

    Application of antitumor chemotherapeutic drugs is hindered by a number of barriers, multidrug resistance that makes effective drug deposition inside cancer cells difficult is among them. Recent research shows that potential efficiency of anticancer drugs can be increased with nanoparticles. This review is devoted to the application of nanoparticles for cancer treatment. Various types of nanoparticles currently used in medicine are reviewed. The nanoparticles that have been used for cancer therapy and targeted drug delivery to damaged sites of organism are described. Also, the possibility of nanoparticles application for cancer diagnosis that could help early detection of tumors is discussed. Our investigations of antitumor activity of low-dimensional nanostructures based on aluminum oxides and hydroxides are briefly reviewed.

  5. Effective field theory approaches for tensor potentials

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Maximilian

    2016-11-14

    Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev

  6. System-Level Heat Transfer Analysis, Thermal- Mechanical Cyclic Stress Analysis, and Environmental Fatigue Modeling of a Two-Loop Pressurized Water Reactor. A Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish [Argonne National Lab. (ANL), Argonne, IL (United States); Soppet, William [Argonne National Lab. (ANL), Argonne, IL (United States); Majumdar, Saurin [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, Ken [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-03

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable in April 2015 under the work package for environmentally assisted fatigue under DOE's Light Water Reactor Sustainability program. In this report, updates are discussed related to a system level preliminary finite element model of a two-loop pressurized water reactor (PWR). Based on this model, system-level heat transfer analysis and subsequent thermal-mechanical stress analysis were performed for typical design-basis thermal-mechanical fatigue cycles. The in-air fatigue lives of components, such as the hot and cold legs, were estimated on the basis of stress analysis results, ASME in-air fatigue life estimation criteria, and fatigue design curves. Furthermore, environmental correction factors and associated PWR environment fatigue lives for the hot and cold legs were estimated by using estimated stress and strain histories and the approach described in NUREG-6909. The discussed models and results are very preliminary. Further advancement of the discussed model is required for more accurate life prediction of reactor components. This report only presents the work related to finite element modelling activities. However, in between multiple tensile and fatigue tests were conducted. The related experimental results will be presented in the year-end report.

  7. Effective exchange potentials for electronically inelastic scattering

    International Nuclear Information System (INIS)

    Schwenke, D.W.; Staszewska, G.; Truhlar, D.G.

    1983-01-01

    We propose new methods for solving the electron scattering close coupling equations employing equivalent local exchange potentials in place of the continuum-multiconfiguration-Hartree--Fock-type exchange kernels. The local exchange potentials are Hermitian. They have the correct symmetry for any symmetries of excited electronic states included in the close coupling expansion, and they have the same limit at very high energy as previously employed exchange potentials. Comparison of numerical calculations employing the new exchange potentials with the results obtained with the standard nonlocal exchange kernels shows that the new exchange potentials are more accurate than the local exchange approximations previously available for electronically inelastic scattering. We anticipate that the new approximations will be most useful for intermediate-energy electronically inelastic electron--molecule scattering

  8. Potential proliferative effect of lipopolysaccharide preconditioning on ...

    African Journals Online (AJOL)

    User

    2015-04-01

    Apr 1, 2015 ... Full Length Research Paper. Potential ... strated to have stem-cell like as well as mature endo- ... TLR4 functions to maintain the stem cell phenotype of .... prepared; first strand buffer (10x) 5 µl, 10 mM dNTP's, RNase inhibitor ...

  9. An effective pair potential for liquid semiconductor, Se: Structure and ...

    Indian Academy of Sciences (India)

    The effective pair potential of liquid semiconductor Se is extracted from its experimental structure factor data using an accurate liquid state theory and this shows important basic features. A model potential incorporating the basic features of the structure factor extracted potential is suggested. This model potential is then used ...

  10. Potential climatic effects of anthropogenic aerosols

    International Nuclear Information System (INIS)

    Pueschel, R.F.

    1993-01-01

    Aerosols act as part of the climate system through their influence on solar and terrestrial radiation. The effect of anthropogenic aerosols on the reduction of visibility is explored in this chapter. Elemental carbon has been identified as the most effective visibility-reducing species. Most of the visibility reduction is due to particles with diameter smaller than 2.5 μm. Studies indicate that sulfate is also a very important aerosol species that results in low visibility and high turbidity. Radiative properties such as aerosol single-scattering albedo values and absorption-to-backscatter ratios purported to produce warming or cooling effects of aerosols are discussed. It is concluded that aerosol clouds have a tendency to cool when they are over a low-albedo surface and have a tendency to warm when they are over high-albedo surfaces such as snow. Anthropogenic aerosols have a tendency to warm the earth's atmospheric system, based on calculations and assumed aerosol optical properties. However, this effect is somewhat offset by the absorption and re-emission into space of infrared terrestrial radiation. The net effect depends on the ratio of the absorption coefficients in the visible and infrared and also on the surface albedo. The effects on infrared radiation are documented for two anthropogenic aerosol sources in the United States, the Denver metropolitan area and power plant plumes in New Mexico, through calculations and measurements. Measured cooling rates within an aerosol plume are not sufficient to offset the warming rate due to absorption of short-wave radiation. Research indicates that anthropogenic aerosols can possibly cause local-scale warming of the atmosphere, but global-scale climatic effects remain an open question

  11. Temperature corrections, supersymmetric effective potentials and inflation

    International Nuclear Information System (INIS)

    Binetruy, P.; Gaillard, M.K.; California Univ., Berkeley

    1985-01-01

    We calculate the one-loop temperature corrections to general potentials in N=1 supergravity, and study the conditions under which a new inflationary scenario is possible. The results are sensitive to the total number N of chiral superfields. For large N, we find that in 'hidden sector' models supersymmetry must be broken at a scale governed by the energy density of the false vacuum: msub(3/2) > or approx. 2√8π μ 2 /Msub(p), where μ approx.= (10 -3 -10 -4 )Msub(p) in typical inflationary scenarios. We also discuss an alternative picture where inflation occurs at the preonic level, before the preon-confining phase transition. (orig.)

  12. The potential health effects of dietary phytoestrogens

    NARCIS (Netherlands)

    Rietjens, Ivonne M.C.M.; Louisse, Jochem; Beekmann, Karsten

    2017-01-01

    Phytoestrogens are plant-derived dietary compounds with structural similarity to 17-β-oestradiol (E2), the primary female sex hormone. This structural similarity to E2 enables phytoestrogens to cause (anti)oestrogenic effects by binding to the oestrogen receptors. The aim of the present review is to

  13. Effective Kratzer and Coulomb potentials as limit cases of a multiparameter exponential-type potential

    Energy Technology Data Exchange (ETDEWEB)

    García-Ravelo, J., E-mail: g.ravelo@hotmail.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Menéndez, A.; García-Martínez, J. [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Schulze-Halberg, A. [Department of Mathematics and Actuarial Science and Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, IN 46408 (United States)

    2014-06-13

    We show that the effective Kratzer and Coulomb potentials can be obtained by taking particular limits of a multiparameter exponential potential that was studied recently. Moreover, we demonstrate that the bound state solutions of the exponential potential reduce correctly to their well-known counterparts associated with the Kratzer and Coulomb potentials. As a byproduct, we obtain a new limit relation for the hypergeometric function. - Highlights: • Kratzer and Coulomb potentials are limit cases of an exponential-type potential. • From exact s-waves, approximate solutions for l-waves are obtained. • l-waves of the potential tend to the solutions of the Kratzer and Coulomb potentials. • A non-evident identity between hypergeometric functions is demonstrated.

  14. Effective Kratzer and Coulomb potentials as limit cases of a multiparameter exponential-type potential

    International Nuclear Information System (INIS)

    García-Ravelo, J.; Menéndez, A.; García-Martínez, J.; Schulze-Halberg, A.

    2014-01-01

    We show that the effective Kratzer and Coulomb potentials can be obtained by taking particular limits of a multiparameter exponential potential that was studied recently. Moreover, we demonstrate that the bound state solutions of the exponential potential reduce correctly to their well-known counterparts associated with the Kratzer and Coulomb potentials. As a byproduct, we obtain a new limit relation for the hypergeometric function. - Highlights: • Kratzer and Coulomb potentials are limit cases of an exponential-type potential. • From exact s-waves, approximate solutions for l-waves are obtained. • l-waves of the potential tend to the solutions of the Kratzer and Coulomb potentials. • A non-evident identity between hypergeometric functions is demonstrated

  15. Beyond the Coleman–Weinberg Effective Potential

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    The Two-Particle-Irreducible (2PI) formalism as introduced by Cornwall, Jackiw and Tomboulis provides a systematic analytic approach to consistently describing non-perturbative phenomena in Quantum Field Theory. In spite of its great success, one major problem of the 2PI approach is that its loopwise expansion gives rise to residual violations of symmetries and hence to massive Goldstone bosons in the spontaneously broken phase of the theory. In my talk I will present a novel symmetry-improved 2PI formalism which consistently encodes global symmetries in a loopwise expansion. Unlike other methods, I will illustrate how the symmetry-improved 2PI effective action satisfies a number of important field-theoretic properties, such as the masslessness of the Goldstone boson and the fact that the phase transition is of second order in O(N) theories, already in the Hartree-Fock approximation. After taking the sunset diagrams into account, I show how the symmetry-improved 2PI approach properly describe...

  16. Matter-wave bright solitons in effective bichromatic lattice potentials

    Indian Academy of Sciences (India)

    Matter-wave bright solitons in bichromatic lattice potentials are considered and their dynamics for different lattice environments are studied. Bichromatic potentials are created from superpositions of (i) two linear optical lattices and (ii) a linear and a nonlinear optical lattice. Effective potentials are found for the solitons in both ...

  17. Effective potential for bilocal composite fields and its ambiguity

    International Nuclear Information System (INIS)

    Muta, T.

    1988-01-01

    It is discussed that an ambiguity exists in the definition of the effective potential for bilocal composite fields which is an indispensable tool to discuss dynamical symmetry breaking. The ambiguity gives warning to arguments on the stability of ground states based on the curvature of the effective potential

  18. Effects of Potential Lane-Changing Probability on Uniform Flow

    International Nuclear Information System (INIS)

    Tang Tieqiao; Huang Haijun; Shang Huayan

    2010-01-01

    In this paper, we use the car-following model with the anticipation effect of the potential lane-changing probability (Acta Mech. Sin. 24 (2008) 399) to investigate the effects of the potential lane-changing probability on uniform flow. The analytical and numerical results show that the potential lane-changing probability can enhance the speed and flow of uniform flow and that their increments are related to the density.

  19. Ultrasoft renormalization of the potentials in vNRQCD

    Energy Technology Data Exchange (ETDEWEB)

    Stahlhofen, Maximilian Horst

    2009-02-18

    The effective field theory vNRQCD allows to describe among others the production of top-antitop pairs in electron-positron collisions at threshold, i.e. with very small relative velocity {upsilon} << 1 of the quarks. Potentially large logarithms {proportional_to} ln {upsilon} are systematically summed up and lead to a scale dependence of the Wilson coefficients of the theory. The missing contributions to the cross section {sigma}(e{sup +}e{sup -} {yields} t anti t) in the resonance region at NNLL level are the so-called mixing contributions to the NNLL anomalous dimension of the S-wave production/annihilation current of the topquark pair. To calculate these one has to know the NLL renormalization group running of so-called potentials (4-quark operators). The dominant contributions to the anomalous dimension of these potentials come from vNRQCD diagrams with ultrasoft gluon loops. The aim of this thesis is to derive the complete ultrasoft NLL running of the relevant potentials. For that purpose the UV divergent parts of about 10{sup 4} two-loop diagrams are determined. Technical and conceptional issues are discussed. Some open questions related to the calculation of the non-Abelian two-loop diagrams arise. Preliminary results are analysed with regard to the consequences for the mentioned cross section and its theoretical uncertainty. (orig.)

  20. Effective potential in Lorentz-breaking field theory models

    Energy Technology Data Exchange (ETDEWEB)

    Baeta Scarpelli, A.P. [Centro Federal de Educacao Tecnologica, Nova Gameleira Belo Horizonte, MG (Brazil); Setor Tecnico-Cientifico, Departamento de Policia Federal, Belo Horizonte, MG (Brazil); Brito, L.C.T. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Felipe, J.C.C. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Universidade Federal dos Vales do Jequitinhonha e Mucuri, Instituto de Engenharia, Ciencia e Tecnologia, Veredas, Janauba, MG (Brazil); Nascimento, J.R.; Petrov, A.Yu. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil)

    2017-12-15

    We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

  1. Electronic structure of molecules using relativistic effective core potentials

    International Nuclear Information System (INIS)

    Hay, P.J.

    1983-01-01

    In this review an approach is outlined for studying molecules containing heavy atoms with the use of relativistic effective core potentials (RECP's). These potentials play the dual roles of (1) replacing the chemically-inert core electrons and (2) incorporating the mass velocity and Darwin term into a one-electron effective potential. This reduces the problem to a valence-electron problem and avoids computation of additional matrix elements involving relativistic operators. The spin-orbit effects are subsequently included using the molecular orbitals derived from the RECP calculation as a basis

  2. Effective potential in Lorentz-breaking field theory models

    International Nuclear Information System (INIS)

    Baeta Scarpelli, A.P.; Brito, L.C.T.; Felipe, J.C.C.; Nascimento, J.R.; Petrov, A.Yu.

    2017-01-01

    We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

  3. Directly patching high-level exchange-correlation potential based on fully determined optimized effective potentials

    Science.gov (United States)

    Huang, Chen; Chi, Yu-Chieh

    2017-12-01

    The key element in Kohn-Sham (KS) density functional theory is the exchange-correlation (XC) potential. We recently proposed the exchange-correlation potential patching (XCPP) method with the aim of directly constructing high-level XC potential in a large system by patching the locally computed, high-level XC potentials throughout the system. In this work, we investigate the patching of the exact exchange (EXX) and the random phase approximation (RPA) correlation potentials. A major challenge of XCPP is that a cluster's XC potential, obtained by solving the optimized effective potential equation, is only determined up to an unknown constant. Without fully determining the clusters' XC potentials, the patched system's XC potential is "uneven" in the real space and may cause non-physical results. Here, we developed a simple method to determine this unknown constant. The performance of XCPP-RPA is investigated on three one-dimensional systems: H20, H10Li8, and the stretching of the H19-H bond. We investigated two definitions of EXX: (i) the definition based on the adiabatic connection and fluctuation dissipation theorem (ACFDT) and (ii) the Hartree-Fock (HF) definition. With ACFDT-type EXX, effective error cancellations were observed between the patched EXX and the patched RPA correlation potentials. Such error cancellations were absent for the HF-type EXX, which was attributed to the fact that for systems with fractional occupation numbers, the integral of the HF-type EXX hole is not -1. The KS spectra and band gaps from XCPP agree reasonably well with the benchmarks as we make the clusters large.

  4. The effect of membrane diffusion potential change on anionic drugs ...

    African Journals Online (AJOL)

    The effect of membrane potential change on anionic drugs Indomethacin and barbitone induced human erythrocyte shape change and red cell uptake of drug has been studied using microscopy and spectrophotometry techniques respectively. The membrane potential was changed by reducing the extracellular chloride ...

  5. Effects of treated poultry litter on potential greenhouse gas emission ...

    African Journals Online (AJOL)

    A study was conducted to evaluate the effects of different treatments of poultry faecal waste on potential greenhouse gas emission and inherent agronomic potentials. Sugar solution at 100g/l salt solution at 350g/l and oven-drying were the various faecal treatments examined using a completely randomized design.

  6. Attention effects at auditory periphery derived from human scalp potentials: displacement measure of potentials.

    Science.gov (United States)

    Ikeda, Kazunari; Hayashi, Akiko; Sekiguchi, Takahiro; Era, Shukichi

    2006-10-01

    It is known in humans that electrophysiological measures such as the auditory brainstem response (ABR) are difficult to identify the attention effect at the auditory periphery, whereas the centrifugal effect has been detected by measuring otoacoustic emissions. This research developed a measure responsive to the shift of human scalp potentials within a brief post-stimulus period (13 ms), that is, displacement percentage, and applied it to an experiment to retrieve the peripheral attention effect. In the present experimental paradigm, tone pips were exposed to the left ear whereas the other ear was masked by white noise. Twelve participants each conducted two conditions of either ignoring or attending to the tone pips. Relative to averaged scalp potentials in the ignoring condition, the shift of the potentials was found within early component range during the attentive condition, and displacement percentage then revealed a significant magnitude difference between the two conditions. These results suggest that, using a measure representing the potential shift itself, the peripheral effect of attention can be detected from human scalp potentials.

  7. Effect of Ionic Diffusion on Extracellular Potentials in Neural Tissue.

    Directory of Open Access Journals (Sweden)

    Geir Halnes

    2016-11-01

    Full Text Available Recorded potentials in the extracellular space (ECS of the brain is a standard measure of population activity in neural tissue. Computational models that simulate the relationship between the ECS potential and its underlying neurophysiological processes are commonly used in the interpretation of such measurements. Standard methods, such as volume-conductor theory and current-source density theory, assume that diffusion has a negligible effect on the ECS potential, at least in the range of frequencies picked up by most recording systems. This assumption remains to be verified. We here present a hybrid simulation framework that accounts for diffusive effects on the ECS potential. The framework uses (1 the NEURON simulator to compute the activity and ionic output currents from multicompartmental neuron models, and (2 the electrodiffusive Kirchhoff-Nernst-Planck framework to simulate the resulting dynamics of the potential and ion concentrations in the ECS, accounting for the effect of electrical migration as well as diffusion. Using this framework, we explore the effect that ECS diffusion has on the electrical potential surrounding a small population of 10 pyramidal neurons. The neural model was tuned so that simulations over ∼100 seconds of biological time led to shifts in ECS concentrations by a few millimolars, similar to what has been seen in experiments. By comparing simulations where ECS diffusion was absent with simulations where ECS diffusion was included, we made the following key findings: (i ECS diffusion shifted the local potential by up to ∼0.2 mV. (ii The power spectral density (PSD of the diffusion-evoked potential shifts followed a 1/f2 power law. (iii Diffusion effects dominated the PSD of the ECS potential for frequencies up to several hertz. In scenarios with large, but physiologically realistic ECS concentration gradients, diffusion was thus found to affect the ECS potential well within the frequency range picked up in

  8. Effective Form of Reproducing the Total Financial Potential of Ukraine

    Directory of Open Access Journals (Sweden)

    Portna Oksana V.

    2015-03-01

    Full Text Available Development of scientific principles of reproducing the total financial potential of the country and its effective form is an urgent problem both in theoretical and practical aspects of the study, the solution of which is intended to ensure the active mobilization and effective use of the total financial potential of Ukraine, and as a result — its expanded reproduction as well, which would contribute to realization of the internal capacities for stabilization of the national economy. The purpose of the article is disclosing the essence of the effective form of reproducing the total financial potential of the country, analyzing the results of reproducing the total financial potential of Ukraine. It has been proved that the basis for the effective form of reproducing the total financial potential of the country is the volume and flow of resources, which are associated with the «real» economy, affect the dynamics of GDP and define it, i.e. resource and process forms of reproducing the total financial potential of Ukraine (which precede the effective one. The analysis of reproducing the total financial potential of Ukraine has shown that in the analyzed period there was an increase in the financial possibilities of the country, but steady dynamics of reduction of the total financial potential was observed. If we consider the amount of resources involved in production, creating a net value added and GDP, it occurs on a restricted basis. Growth of the total financial potential of Ukraine is connected only with extensive quantitative factors rather than intensive qualitative changes.

  9. Two loop calculations for the propagators of gluonic currents jsub(PG)=αGsub(μγ)sup(a)[Gsub(a)sup(μγ)(mean)] and jsub(SG)=[β(α)/α]Gsub(μγ)2

    International Nuclear Information System (INIS)

    Kataev, A.L.; Krasnikov, N.V.; Pivovarov, A.A.

    1981-10-01

    The authors calculate two loop corrections to the propagators of gluonic currents jsub(PG)=αGsub(μγ)sup(a)[Gsub(a)sup(μγ)(mean)] and jsub(SG)=[β(α)/α]Gsub(μγ) 2 . The results of the calculations are used for finding the connection between the characteristic scales of quark and gluonic worlds in perturbative QCD and estimate of the mass of the first radial excitation of eta'-meson (the authors obtain (msub(eta') = 1.45 GeV)). (Auth.)

  10. Effective interionic pair potentials in liquid alkali metals

    International Nuclear Information System (INIS)

    Kumaravadivel, R.

    1984-06-01

    Information on the effective pair potential of liquid alkali metals is obtained from liquid structure factor data by the combination of two approximate methods in the theory of liquids. One method stems from treating the indirect ion-ion interaction in the optimised random phase approximation (ORPA) and the other uses the modified hypernetted chain (MHNC) equation. It is shown that, in the region of the main attractive well, the effective pair potential is bracketed by the results obtained from these two methods. The MHNC inversion scheme does not fare well in providing information on the potential in the region of interionic distance in the tail of the interionic potential. A cross-over from the hard-sphere bridge function to the mean spherical approximation (MSA) bridge function for the long range behaviour of the bridge term in the MHNC equation does not provide appreciable improvement. (author)

  11. Gauge invariance and the effective potential: the Abelian Higgs model

    International Nuclear Information System (INIS)

    Ramaswamy, S.

    1995-01-01

    The gauge invariance of the effective potential in the Abelian Higgs model is examined. The Nielsen identities, which ensure gauge independence of the effective potential and other physical quantities, are shown to hold at finite temperature and in the presence of the chemical potential. It is also shown that, as a consequence of the Nielsen identities, the standard order parameter for symmetry breaking, namely the scalar field vacuum expectation value, has a non-zero parametric dependence on the gauge choice employed. These are then verified to one loop at finite temperature. High-temperature symmetry breaking is considered. In the leading high-temperature limit, the potential agrees with the previous calculations. (orig.)

  12. Selective effects of an octopus toxin on action potentials

    Science.gov (United States)

    Dulhunty, Angela; Gage, Peter W.

    1971-01-01

    1. A lethal, water soluble toxin (Maculotoxin, MTX) with a molecular weight less than 540, can be extracted from the salivary glands of an octopus (Hapalochlaena maculosa). 2. MTX blocks action potentials in sartorius muscle fibres of toads without affecting the membrane potential. Delayed rectification is not inhibited by the toxin. 3. At low concentrations (10-6-10-5 g/ml.) MTX blocks action potentials only after a certain number have been elicited. The number of action potentials, which can be defined accurately, depends on the concentration of MTX and the concentration of sodium ions in the extracellular solution. 4. The toxin has no post-synaptic effect at the neuromuscular junction and it is concluded that it blocks neuromuscular transmission by inhibiting action potentials in motor nerve terminals. PMID:4330930

  13. Additional potential effects of nuclear war on ecological systems

    International Nuclear Information System (INIS)

    Hutchinson, T.C.; Harwell, M.A.; Cropper, W.P. Jr.; Grover, H.D.

    1985-01-01

    The authors summarize biological and ecosystem responses to enhanced UV-B, air pollutants, radiation, and fire. The concentrations and biological responses associated with these perturbations are based on current experience and experimentation. Additional research is needed to quantify probable post-nuclear war exposures and potential responses. A summary is provided of all the potential effects of nuclear war on the variety of the Earth's ecosystems, including perturbations from climatic alterations, radiation, pollutants, and UV-B

  14. Effective potentials from complex simulations: a potential-matching algorithm and remarks on coarse-grained potentials

    International Nuclear Information System (INIS)

    Toth, Gergely

    2007-01-01

    The projection of complex interactions onto simple distance-dependent or angle-dependent classical mechanical functions is a long-standing theoretical challenge in the field of computational sciences concerning biomolecules, colloids, aggregates and simple systems as well. The construction of an effective potential may be based on theoretical assumptions, on the application of fitting procedures on experimental data and on the simplification of complex molecular simulations. Recently, a force-matching method was elaborated to project the data of Car-Parrinello ab initio molecular dynamics simulations onto two-particle classical interactions (Izvekov et al 2004 J. Chem. Phys. 120 10896). We have developed a potential-matching algorithm as a practical analogue of this force-matching method. The algorithm requires a large number of configurations (particle positions) and a single value of the potential energy for each configuration. We show the details of the algorithm and the test calculations on simple systems. The test calculation on water showed an example in which a similar structure was obtained for qualitatively different pair interactions. The application of the algorithm on reverse Monte Carlo configurations was tried as well. We detected inconsistencies in a part of our calculations. We found that the coarse graining of potentials cannot be performed perfectly both for the structural and the thermodynamic data. For example, if one applies an inverse method with an input of the pair-correlation function, it provides energetics data for the configurations uniquely. These energetics data can be different from the desired ones obtained by all atom simulations, as occurred in the testing of our potential-matching method

  15. Quark motional effects on the interquark potential in baryons

    International Nuclear Information System (INIS)

    Yamamoto, Arata; Suganuma, Hideo

    2008-01-01

    We study the heavy-heavy-light quark (QQq) system in a nonrelativistic potential model, and investigate the quark motional effect on the inter-two-quark potential in baryons. We adopt the Hamiltonian with the static three-quark potential which is obtained by the first-principle calculation of lattice QCD, rather than the two-body force in ordinary quark models. Using the renormalization-group inspired variational method in discretized space, we calculate the ground-state energy of QQq systems and the light-quark spatial distribution. We find that the effective string tension between the two heavy quarks is reduced compared to the static three-quark case. This reduction of the effective string tension originates from the geometrical difference between the interquark distance and the flux-tube length, and is conjectured to be a general property for baryons

  16. The acute potentiating effects of back squats on athlete performance.

    Science.gov (United States)

    Crewther, Blair T; Kilduff, Liam P; Cook, Christian J; Middleton, Matt K; Bunce, Paul J; Yang, Guang-Zhong

    2011-12-01

    Crewther, BT, Kilduff, LP, Cook, CJ, Middleton, MK, Bunce, PJ, and Yang, G-Z. The acute potentiating effects of back squats on athlete performance. J Strength Cond Res 25(12): 3319-3325, 2011-This study examined the acute potentiating effects of back squats on athlete performance with a specific focus on movement specificity and the individual timing of potentiation. Nine subelite male rugby players performed 3 protocols on separate occasions using a randomized, crossover, and counterbalanced design. Each protocol consisted of performance testing before a single set of 3 repetition maximum (3RM) back squats, followed by retesting at ∼15 seconds, 4, 8, 12, and 16 minutes. The 3 tests were countermovement jumps (CMJs), sprint performance (5 and 10 m), and 3-m horizontal sled pushes with a 100-kg load. Relationships between the individual changes in salivary testosterone and cortisol concentrations and performance were also examined. The 3RM squats significantly (p squats was found effective in acutely enhancing CMJ height in the study population, especially when the recovery period was individualized for each athlete. The study results also suggest that the potentiating effects of squats may exhibit some degree of movement specificity, being greater for those exercises with similar movement patterns. The current findings have practical implications for prescribing warm-up exercises, individualizing training programs, and for interpreting postactivation potentiation research.

  17. Percolation temperature and the 'instability' of the effective potential

    International Nuclear Information System (INIS)

    Carvalho, C.A. de; Bazeia Filho, D.; Eboli, O.J.P.; Marques, G.C.; Silva, A.J. da; Ventura, I.

    1984-01-01

    It is shown that in spontaneously broken lambda phi 4 theory the percolation temperature coincides with the temperature at which the semiclassical (loop) expansion of the effective potential (free energy) of the system around a uniform field configuration fails. This allows us to extract the percolation temperature directly from the effective potential. The addition of fermions or gauge fields does not alter the result as long as they are weakly coupled to the scalars. The coincidence holds in the high temperature limit at every order in the loop expansion. (Author) [pt

  18. Effect of ionizing radiation on transmembrane potential of Streptococcus

    International Nuclear Information System (INIS)

    Fomenko, B.S.; Akoev, I.G.

    1979-01-01

    Treatment of Streptococcus faecalis with ionizing radiation at doses of 5 to 100 krad is shown to reduce the energy-dependent accumulation of dibenzyldimethylammonium (DDA + ) by the cell. Since transmembrane potential is the moving force of DDA + transport across the membrane, the decrease in DDA + accumulation is suggested to be due to potential reduction. This radiation effect was not due to inactivation of the potential-generating mechanism; thus, the ATPase activity and glycolytic activity of the irradiated cells were higher than in the control. At the same time, the membranes exhibited an increased permeability for K + and protons, which is probably due to structural rearrangements in the membranes after irradiation. It is suggested that the potential reduction results from the increase in proton permeability of membranes

  19. Color screening effect in the quark potential model

    International Nuclear Information System (INIS)

    Zhang Zongye; Yu Youwen; Shen Pengnian; Shen Xiaoyan; Dong Yubin

    1993-01-01

    By using the color confinement potential which includes the color screening effect, we studied the baryon spectra and the nucleon-nucleon interaction. The results show that the color screening effect not only improves the baryon spectrum calculation, but also can solve the long-tail problem of the color Van der Waals force. A part of the medium attraction of the nuclear force can be obtained from the color Van der Waals force. (orig.)

  20. One-loop effective potential on hyperbolic manifolds

    International Nuclear Information System (INIS)

    Cognola, G.; Kirsten, K.; Zerbini, S.

    1993-01-01

    The one-loop effective potential for a scalar field defined on an ultrastatic space-time whose spatial part is a compact hyperbolic manifold is studied using ζ-function regularization for the one-loop effective action. Other possible regularizations are discussed in detail. The renormalization group equations are derived, and their connection with the conformal anomaly is pointed out. The symmetry breaking and the topological mass generation are also discussed

  1. The effects of water potential on some microbial populations and ...

    African Journals Online (AJOL)

    The effects of water potential on some microbial populations and decrease kinetic of organic carbon in soil treated with cow manure under laboratory conditions. ... Fourth irrigation treatment was drying-rewetting cycle (D-W) between -0.3 to -15 bars. After 0, 10, 20, 40, 60 and 90 days of incubation, soils were sampled for ...

  2. Reconstruction of atomic effective potentials from isotropic scattering factors

    International Nuclear Information System (INIS)

    Romera, E.; Angulo, J.C.; Torres, J.J.

    2002-01-01

    We present a method for the approximate determination of one-electron effective potentials of many-electron systems from a finite number of values of the isotropic scattering factor. The method is based on the minimum cross-entropy technique. An application to some neutral ground-state atomic systems has been done within a Hartree-Fock framework

  3. Linking flow, water quality and potential effects on aquatic biota ...

    African Journals Online (AJOL)

    Linking the potential effects of altered water quality on aquatic biota, that may result from a change in the flow (discharge) regime, is an essential step in the maintenance of riverine ecological functioning. Determination of the environmental flow requirement of a river (as well as other activities, such as classifying the ...

  4. Effects of treated poultry litter on potential Greenhouse Gas ...

    African Journals Online (AJOL)

    This study examined the effects of different treatments of poultry faecal matter on potential greenhouse gas emission and its field application. Poultry litters were randomly assigned to four treatments viz; salt solution, alum, air exclusion and the control (untreated). Alum treated faeces had higher (p<0.05) percentage nitrogen ...

  5. Potential Effects of the Adoption and Implementstion of International ...

    African Journals Online (AJOL)

    The objective of this study is to examine the potential effects of the adoption and implementation of IFRS in Nigeria from the perspective of stakeholders. It presents the results from a questionnaire survey of a sample of accounting lecturers, auditors and accountants. The data were analyzed using the Chi Square. The study ...

  6. Electronic structure of molecules using relativistic effective core potentials

    International Nuclear Information System (INIS)

    Hay, P.J.

    1981-01-01

    Starting with one-component Cowan-Griffin relativistic Hartree-Fock orbitals, which successfully incorporate the mass-velocity and Darwin terms present in more complicated wavefunctions such as Dirac-Hartree-Fock, one can derive relativistic effective core potentials (RECP's) to carry out molecular calculations. These potentials implicitly include the dominant relativistic terms for molecules while allowing one to use the traditional quantum chemical techniques for studying the electronic structure of molecules. The effects of spin-orbit coupling can then be included using orbitals from such calculations using an effective 1-electron, 1-center spin-orbit operator. Applications to molecular systems involving heavy atoms, show good agreement with available spectroscopic data on molecular geometries and excitation energies

  7. Interaction potentials and their effect on crystal nucleation and symmetry

    International Nuclear Information System (INIS)

    Hsu, C.S.; Rahman, A.

    1979-01-01

    Molecular dynamics technique has been used to study the effect of the interaction potential on crystal nucleation and the symmetry of the nucleated phase. Four systems, namely rubidium, Lennard-Jones, rubidium-truncated, and Lennard-Jones-truncated, have been studied each at reduced density 0.95. Two types of calculations were performed. Firstly, starting from a liquid state, each system was quenched rapidly to a reduced temperature of approx.0.1. The nucleation process for these systems was monitored by studying the time dependence of temperature and the pair correlation function, and the resulting crystalline structure analyzed using among other properties the Voronoi polyhedra. Only in the case of rubidium was a b.c.c. structure nucleated. In the other three cases we obtained a f.c.c. ordering. Secondly, we have studied the effect of changing the interaction potential in a system which has already achieved an ordered state under the action of some other potential. After establishing a b.c.c. structure in a rubidium system, the change in the symmetry of the system was studied when the pair potential was modified to one of the other three forms. The results from both types of calculations are consistent: the rubidium potential leads to a b.c.c. structure while the other three potentials give an f.c.c. structure. Metastable disordered structures were not obtained in any of the calculations. However, the time elapse between the moment when the system is quick-quenched and the moment when nucleation occurs appears to depend upon the potential of interaction

  8. PRODUCTION POTENTIAL AND AGRICULTURAL EFFECTIVENESS IN EUROPEAN UNION COUNTRIES

    Directory of Open Access Journals (Sweden)

    Agnieszka Baer-Nawrocka

    2013-09-01

    Full Text Available The aim of the paper was to assess the relation between agricultural production factors and effectiveness in European Union’s agriculture. For each country two synthetic coefficients were calculated using TOPSIS method. The first one characterises production factors relations, the latter one displays effectiveness of production factors. The objective of the research was to verify the correlation between these indices. The analysis proved that in many analysed countries the agricultural potential is correlated positively with the agricultural effectiveness

  9. Study on the nonlocality effects for generalized optical potentials

    International Nuclear Information System (INIS)

    Gurbanovich, I.S.; Zelenskaya, N.S.

    1981-01-01

    In previous studies the authors have ihown that the generalized optic potential (GOP) of particles interaction is a superposition of local and non local potentials (LP, NLP). On the example of α- particles scattering on the 8 Be nucleus at about 10-15 MeV the GOP nonlocal part is considered. For obtaining NLP the spectral decomposition of the Green function taking into account only contribution of relative motion of two α-particles in S-state is used. The locally-equivalent addition to central potential of α-particles scattering at 8 Be previously calculated is obtained. In a graphical form a total locally-equivalent potential and local GOP part are presented. It is shown that taking into account the nonlocallity effect in a locally energy approximation for precise wave function in S-state widen a potential hole without changing its depth. Such widening corresponds to the general character of behaviour of non local potentials calculated in the microscopic approach [ru

  10. Comparison of potential models through heavy quark effective theory

    International Nuclear Information System (INIS)

    Amundson, J.F.

    1995-01-01

    I calculate heavy-light decay constants in a nonrelativistic potential model. The resulting estimate of heavy quark symmetry breaking conflicts with similar estimates from lattice QCD. I show that a semirelativistic potential model eliminates the conflict. Using the results of heavy quark effective theory allows me to identify and compensate for shortcomings in the model calculations in addition to isolating the source of the differences in the two models. The results lead to a rule as to where the nonrelativistic quark model gives misleading predictions

  11. Towards a Kohn-Sham potential via the optimized effective-potential method

    International Nuclear Information System (INIS)

    Norman, M.R.; Koelling, D.D.

    1984-01-01

    The optimized effective-potential (OEP) method is applied to a self-interaction-corrected local-spin-density (SIC-LSD) energy functional. The local potential which results has the useful properties of being both self-interaction free and orbital independent, and it can thus be regarded as a good approximation to the exact Kohn-Sham potential. A number of atomic systems are examined in the exchange-only and in the Ceperley-Alder exchange-correlation approximations. The resulting total energies are very close to those obtained by previous applications of the LSD-SIC functional. The resultant potentials are structurally similar to those derived by applying the OEP method to a Hartree-Fock Hamiltonian: showing much improved behavior over the local-spin-density approximation in both large- and small-r regions as well as the characteristic intershell cusplike structure. The eigenvalues have less formal significance than the more standard approaches, especially those for unoccupied orbitals which seem to have no significance whatsoever. Nonetheless, the highest occupied eigenvalue agrees closely with the conventional LSD-SIC value. However, for the deeper levels, each eigenvalue lies higher than the comparable eigenvalue of the conventional SIC, although lower than the eigenvalue of the LSD potential: the deeper the level, the larger the difference. This property follows from the nonvariational character of the eigenvalues, and it is shown that one can obtain realistic excitation spectra from this formalism by utilizing the appropriate variational quantity. The results obtained illustrate some of the less understood issues in the application of the Kohn-Sham procedure within density-functional theory

  12. Music listening after stroke: beneficial effects and potential neural mechanisms.

    Science.gov (United States)

    Särkämö, Teppo; Soto, David

    2012-04-01

    Music is an enjoyable leisure activity that also engages many emotional, cognitive, and motor processes in the brain. Here, we will first review previous literature on the emotional and cognitive effects of music listening in healthy persons and various clinical groups. Then we will present findings about the short- and long-term effects of music listening on the recovery of cognitive function in stroke patients and the underlying neural mechanisms of these music effects. First, our results indicate that listening to pleasant music can have a short-term facilitating effect on visual awareness in patients with visual neglect, which is associated with functional coupling between emotional and attentional brain regions. Second, daily music listening can improve auditory and verbal memory, focused attention, and mood as well as induce structural gray matter changes in the early poststroke stage. The psychological and neural mechanisms potentially underlying the rehabilitating effect of music after stroke are discussed. © 2012 New York Academy of Sciences.

  13. Orbital correlation effects. II. Potential curve and ionization potential of boron hydride

    International Nuclear Information System (INIS)

    Mehler, E.L.; Van der Vele, G.A.; Nieuwpoort, W.C.

    1975-01-01

    With the help of the independent pair-potential approximation (IPPA) the valence-shell correlation effects in BH have been calculated at nine internuclear separations. The results are compared with several other methods, including the coupled electron pair approximation (CEPA) and a full configuration interaction expansion. The stability of the IPPA against a unitary transformation of the occupied orbitals has also been investigated, and it is shown that the IPPA is nearly invariant against such transformations. The Dunham procedure has been applied to the results, and the spectroscopic constants obtained from the various approximations are compared. It is furthermore demonstrated that many of the defects present in the Hartree--Fock part of the potential curve and arising from the use of medium-quality basis sets can be eliminated by combining the correlation results with Hartree--Fock results from good-quality basis sets and reapplying the Dunham procedure. Finally the IPPA has been applied to BH + , and the first vertical ionization potential of BH was determined

  14. Effective potentials in nonlinear polycrystals and quadrature formulae

    Science.gov (United States)

    Michel, Jean-Claude; Suquet, Pierre

    2017-08-01

    This study presents a family of estimates for effective potentials in nonlinear polycrystals. Noting that these potentials are given as averages, several quadrature formulae are investigated to express these integrals of nonlinear functions of local fields in terms of the moments of these fields. Two of these quadrature formulae reduce to known schemes, including a recent proposition (Ponte Castañeda 2015 Proc. R. Soc. A 471, 20150665 (doi:10.1098/rspa.2015.0665)) obtained by completely different means. Other formulae are also reviewed that make use of statistical information on the fields beyond their first and second moments. These quadrature formulae are applied to the estimation of effective potentials in polycrystals governed by two potentials, by means of a reduced-order model proposed by the authors (non-uniform transformation field analysis). It is shown how the quadrature formulae improve on the tangent second-order approximation in porous crystals at high stress triaxiality. It is found that, in order to retrieve a satisfactory accuracy for highly nonlinear porous crystals under high stress triaxiality, a quadrature formula of higher order is required.

  15. Angle-resolved effective potentials for disk-shaped molecules

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, Thomas, E-mail: thomas.heinemann@tu-berlin.de; Klapp, Sabine H. L., E-mail: klapp@physik.tu-berlin.de [Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Palczynski, Karol, E-mail: karol.palczynski@helmholtz-berlin.de; Dzubiella, Joachim, E-mail: joachim.dzubiella@helmholtz-berlin.de [Institut für Physik, Humboldt Universität zu Berlin, Newtonstraße 15, 12489 Berlin (Germany); Helmholtz Zentrum Berlin (HZB), Institute of Soft Matter and Functional Materials, Hahn-Meitner Platz 1, 14109 Berlin (Germany)

    2014-12-07

    We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.

  16. Potential dependence of the effective attraction in doped C60

    International Nuclear Information System (INIS)

    Goff, W.E.; Phillips, P.

    1992-01-01

    In an effort to explain superconductivity in the alkali-doped C 60 , Chakravarty and Kivelson have proposed that there is a net effective electron attraction due to intramolecular Coulomb forces. The calculation makes use of a Hubbard model in which long-range interactions are absent. The authors show that this result strongly depends on the form of the electron-electron interaction and that for potentials with long-range interactions, e.g. an Ohno potential that interpolates between an on site energy and 1/r at large distances, they do not find an effective attraction. Reasonable screening does not significantly modify this result. This indicates that the electronic mechanism in the proposed form cannot be the primary source of an attractive interaction

  17. Ketamine for Pain Management-Side Effects & Potential Adverse Events.

    Science.gov (United States)

    Allen, Cheryl A; Ivester, Julius R

    2017-12-01

    An old anesthetic agent, ketamine is finding new use in lower doses for analgesic purposes. There are concerns stemming from its potential side effects-specifically psychomimetic effects. These side effects are directly related to dose amount. The doses used for analgesic purposes are much lower than those used for anesthesia purposes. A literature review was performed to ascertain potential side effects and/or adverse events when using ketamine for analgesia purposes. The search included CINAHL, PubMed, and Ovid using the search terms "ketamine," "ketamine infusion," "pain," "adverse events," "practice guideline," and "randomized controlled trial." Searches were limited to full-text, peer-reviewed articles and systematic reviews. Initially 1,068 articles were retrieved. The search was then narrowed by using the Boolean connector AND with various search term combinations. After adjusting for duplication, article titles and abstracts were reviewed, leaving 25 articles for an in-depth analysis. Specific exclusion criteria were then applied. The literature supports the use of ketamine for analgesic purposes, and ketamine offers a nonopioid option for the management of some pain conditions. Because ketamine is still classified as an anesthetic agent, health care institutions should develop their own set of policies and protocols for the administration of ketamine. By using forethought and understanding of the properties of ketamine, appropriate care may be planned to mitigate potential side effects and adverse events so that patients are appropriately cared for and their pain effectively managed. Copyright © 2017 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  18. ${ \\mathcal P }{ \\mathcal T }$-symmetric interpretation of unstable effective potentials

    CERN Document Server

    Bender, Carl M.; Mavromatos, Nick E.; Sarkar, Sarben

    2016-01-01

    The conventional interpretation of the one-loop effective potentials of the Higgs field in the Standard Model and the gravitino condensate in dynamically broken supergravity is that these theories are unstable at large field values. A ${ \\mathcal P }{ \\mathcal T }$-symmetric reinterpretation of these models at a quantum-mechanical level eliminates these instabilities and suggests that these instabilities may also be tamed at the quantum-field-theory level.

  19. Potential health effects associated with dermal exposure to occupational chemicals.

    Science.gov (United States)

    Anderson, Stacey E; Meade, B Jean

    2014-01-01

    There are a large number of workers in the United States, spanning a variety of occupational industries and sectors, who are potentially exposed to chemicals that can be absorbed through the skin. Occupational skin exposures can result in numerous diseases that can adversely affect an individual's health and capacity to perform at work. In general, there are three types of chemical-skin interactions of concern: direct skin effects, immune-mediated skin effects, and systemic effects. While hundreds of chemicals (metals, epoxy and acrylic resins, rubber additives, and chemical intermediates) present in virtually every industry have been identified to cause direct and immune-mediated effects such as contact dermatitis or urticaria, less is known about the number and types of chemicals contributing to systemic effects. In an attempt to raise awareness, skin notation assignments communicate the potential for dermal absorption; however, there is a need for standardization among agencies to communicate an accurate description of occupational hazards. Studies have suggested that exposure to complex mixtures, excessive hand washing, use of hand sanitizers, high frequency of wet work, and environmental or other factors may enhance penetration and stimulate other biological responses altering the outcomes of dermal chemical exposure. Understanding the hazards of dermal exposure is essential for the proper implementation of protective measures to ensure worker safety and health.

  20. Bioavailability, metabolism and potential health protective effects of dietary flavonoids

    DEFF Research Database (Denmark)

    Bredsdorff, Lea

    Dietary flavonoids constitute an important group of potential health protective compounds from fruits, vegetables, and plant-based products such as tea and wine. The beneficial effects of a diet high in flavonoids on the risk of coronary heart disease (CHD) have been shown in several epidemiologi......Dietary flavonoids constitute an important group of potential health protective compounds from fruits, vegetables, and plant-based products such as tea and wine. The beneficial effects of a diet high in flavonoids on the risk of coronary heart disease (CHD) have been shown in several...... of their content. In addition, variation in individual metabolic genotype and microflora may greatly affect the actual flavonoid exposure. The preventive effects of flavonoids on CHD are mainly ascribed to their anti-inflammatory and antioxidant activities. Several mechanisms of anti-inflammatory and antioxidant...... effective absorption of hesperetin and naringenin from the small intestine when consumed as glucosides compared to absorption in the colon VII after microbial degradation of the rhamnoglucosides. In addition it was shown that the conjugate profile was neither affected by the absorption site nor by a 3-fold...

  1. Effective potential for spontaneously broken gauge theories and gauge hierarchies

    International Nuclear Information System (INIS)

    Hagiwara, T.; Ovrut, B.

    1979-01-01

    The Appelquist-Carazzone effective-field-theory method, where one uses effective light-field coupling constants dependent on the heavy-field sector, is explicitly shown to be valid for the discussion of the gauge-hierarchy problem in grand unified gauge models. Using the method of functionals we derive an expression for the one-loop approximation to the scalar-field effective potential for spontaneously broken theories in an arbitrary R/sub xi/ gauge. We argue that this potential generates, through its derivatives, valid zero-momentum, one-particle-irreducible vertices for any value of xi (not just the xi→infinity Landau gauge). The equation that the one-loop vacuum correction must satisfy is presented, and we solve this equation for a number of spontaneously broken theories including gauge theories with gauge groups U(1) and SO(3). We find that a one-loop vacuum shift in a massless, non-Goldstone direction occurs via the Coleman-Weinberg mechanism with an effective coupling constant dependent on the heavy-field sector

  2. The Effects of Calorie Restriction in Depression and Potential Mechanisms.

    Science.gov (United States)

    Zhang, Yifan; Liu, Changhong; Zhao, Yinghao; Zhang, Xingyi; Li, Bingjin; Cui, Ranji

    2015-01-01

    Depression, also called major depressive disorder, is a neuropsychiatric disorder jeopardizing an increasing number of the population worldwide. To date, a large number of studies have devoted great attention to this problematic condition and raised several hypotheses of depression. Based on these theories, many antidepressant drugs were developed for the treatment of depression. Yet, the depressed patients are often refractory to the antidepressant therapies. Recently, increasing experimental evidences demonstrated the effects of calorie restriction in neuroendocrine system and in depression. Both basic and clinical investigations indicated that short-term calorie restriction might induce an antidepressant efficacy in depression, providing a novel avenue for treatment. Molecular basis underlying the antidepressant actions of calorie restriction might involve multiple physiological processes, primarily including orexin signaling activation, increased CREB phosphorylation and neurotrophic effects, release of endorphin and ketone production. However, the effects of chronic calorie restriction were quite controversial, in the cases that it often resulted in the long-term detrimental effects via inhibiting the function of 5-HT system and decreasing leptin levels. Here we review such dual effects of calorie restriction in depression and potential molecular basis behind these effects, especially focusing on antidepressant effects.

  3. Cognitive Effects of Air Pollution Exposures and Potential Mechanistic Underpinnings.

    Science.gov (United States)

    Allen, J L; Klocke, C; Morris-Schaffer, K; Conrad, K; Sobolewski, M; Cory-Slechta, D A

    2017-06-01

    This review sought to address the potential for air pollutants to impair cognition and mechanisms by which that might occur. Air pollution has been associated with deficits in cognitive functions across a wide range of epidemiological studies, both with developmental and adult exposures. Studies in animal models are significantly more limited in number, with somewhat inconsistent findings to date for measures of learning, but show more consistent impairments for short-term memory. Potential contributory mechanisms include oxidative stress/inflammation, altered levels of dopamine and/or glutamate, and changes in synaptic plasticity/structure. Epidemiological studies are consistent with adverse effects of air pollutants on cognition, but additional studies and better phenotypic characterization are needed for animal models, including more precise delineation of specific components of cognition that are affected, as well as definitions of critical exposure periods for such effects and the components of air pollution responsible. This would permit development of more circumscribed hypotheses as to potential behavioral and neurobiological mechanisms.

  4. Fructose use in clinical nutrition: metabolic effects and potential consequences.

    Science.gov (United States)

    Moulin, Sandra; Seematter, Gérald; Seyssel, Kevin

    2017-07-01

    The current article presents recent findings on the metabolic effects of fructose. Fructose has always been considered as a simple 'caloric' hexose only metabolized by splanchnic tissues. Nevertheless, there is growing evidence that fructose acts as a second messenger and induces effects throughout the human body. Recent discoveries made possible with the evolution of technology have highlighted that fructose induces pleiotropic effects on different tissues. The fact that all these tissues express the specific fructose carrier GLUT5 let us reconsider that fructose is not only a caloric hexose, but could also be a potential actor of some behaviors and metabolic pathways. The physiological relevance of fructose as a metabolic driver is pertinent regarding recent scientific literature.

  5. Ab initio effective core potentials including relativistic effects. II. Potential energy curves for Xe2, Xe+2, and Xe*2

    International Nuclear Information System (INIS)

    Ermler, W.C.; Lee, Y.S.; Pitzer, K.S.; Winter, N.W.

    1978-01-01

    Potential energy curves for the ground 1 Σ + /sub g/ state of Xe 2 , the first four states of the Xe + 2 ions, and the eight Xe* 2 excimer states corresponding to the addition of a 6ssigma/sub g/ Rydberg electron to these ion cores have been computed using averaged relativistic effective core potentials (AREP) and the self-consistent field approximation for the valence electrons. The calculations were carried out using the LS-coupling scheme with the effects of spin--orbit coupling included in the resulting potential energy curves using an empirical procedure. A comparison of nonrelativistic and averaged relativistic EP's and subsequent molecular calculations indicates that relativistic effects arising from the mass--velocity and Darwin terms are not important for these properties of Xe 2 molecules. Spectroscopic constants for Xe + 2 are in good agreement with all electron CI calculations suggesting that the computed values for Xe* 2 excimers should be reliable. The lifetime for the O/sub u/ + state of the Xe 2 * is computed to be 5.6 nsec which is in the range of the experimentally determined values

  6. Ab initio effective core potentials for molecular calculations. Potentials for main group elements Na to Bi

    International Nuclear Information System (INIS)

    Wadt, W.R.; Hay, P.J.

    1985-01-01

    A consistent set of ab initio effective core potentials (ECP) has been generated for the main group elements from Na to Bi using the procedure originally developed by Kahn. The ECP's are derived from all-electron numerical Hartree--Fock atomic wave functions and fit to analytical representations for use in molecular calculations. For Rb to Bi the ECP's are generated from the relativistic Hartree--Fock atomic wave functions of Cowan which incorporate the Darwin and mass--velocity terms. Energy-optimized valence basis sets of (3s3p) primitive Gaussians are presented for use with the ECP's. Comparisons between all-electron and valence-electron ECP calculations are presented for NaF, NaCl, Cl 2 , Cl 2 - , Br 2 , Br 2 - , and Xe 2 + . The results show that the average errors introduced by the ECP's are generally only a few percent

  7. Improved effective-potential formalism for composite fields

    International Nuclear Information System (INIS)

    Banks, T.; Raby, S.

    1976-01-01

    We develop an effective-potential formalism for studying dynamical symmetry breaking. The potential that we calculate is single-valued and bounded from below. Our formalism incorporates a stability criterion for deciding whether the broken-symmetry solution to the theory is the physical one. In lowest-order calculations in gauge theories we find that the asymmetric theory will be stable if and only if a composite Goldstone boson can be bound. Our conclusion is that in the weak-coupling approximation there is no dynamical spontaneous breakdown in gauge theories. We then use the renormalization group to argue that, if spontaneous breakdown occurs at all, it must also occur for arbitrarily weak coupling. The renormalization group also provides us with evidence that dynamical symmetry breakdown does not occur in infrared-stable theories

  8. Radion effective potential in the brane-world

    International Nuclear Information System (INIS)

    Garriga, Jaume; Pujolas, Oriol; Tanaka, Takahiro

    2001-01-01

    We show that in brane-world scenarios with warped extra dimensions, the Casimir force due to bulk matter fields may be sufficient to stabilize the radion field phi. In particular, we calculate one loop effective potential for phi induced by bulk gravitons and other possible massless bulk fields in the Randall-Sundrum background. This potential has a local extremum, which can be a maximum or a minimum depending on the detailed bulk matter content. If the parameters of the background are chosen so that the hierarchy problem is solved geometrically, then the radion mass induced by Casimir corrections is hierarchically smaller than the TeV. Hence, in this important case, we must invoke an alternative mechanism (classical or nonperturbative) which gives the radion a sizable mass, to make it compatible with observations

  9. Radion effective potential in the brane-world

    Energy Technology Data Exchange (ETDEWEB)

    Garriga, Jaume E-mail: garriga@ifae.es; Pujolas, Oriol; Tanaka, Takahiro

    2001-07-02

    We show that in brane-world scenarios with warped extra dimensions, the Casimir force due to bulk matter fields may be sufficient to stabilize the radion field phi. In particular, we calculate one loop effective potential for phi induced by bulk gravitons and other possible massless bulk fields in the Randall-Sundrum background. This potential has a local extremum, which can be a maximum or a minimum depending on the detailed bulk matter content. If the parameters of the background are chosen so that the hierarchy problem is solved geometrically, then the radion mass induced by Casimir corrections is hierarchically smaller than the TeV. Hence, in this important case, we must invoke an alternative mechanism (classical or nonperturbative) which gives the radion a sizable mass, to make it compatible with observations.

  10. Effect of applied potential on electrochemically reduced technetium diphosphonate radiopharmaceuticals

    International Nuclear Information System (INIS)

    Martin, J.L. Jr.; Heineman, W.R.; Deutsch, E.

    1987-01-01

    Technetium diphosphonate radiopharmaceuticals continue to play a major role in diagnostic nuclear medicine. Their ability to provide both structural and functional information provides a unique advantage which even the more recent imaging techniques cannot provide. The Tc-99m isotope possesses nuclear decay characteristics which allow maximum organ imaging following intravenous injection while delivering a minimal radiation burden to the patient. Due to the diphosphonate ligands' strong affinity for bone, Tc-99m diphosphonate complexes are routinely used for the determination of bone abnormalities such as cancerous tumors. Electrochemical reduction provides the additional parameter needed to increase the yield of a single component. This work presents the effect of varying the applied potential of the mercury pool electrode at selected pH values. The result of this variation in applied potential is tracked by anion exchange chromatographic separation based on the negatively charged Tc-diphosphonate complexes. These chromatograms are compared to those obtained by standard chemical reduction

  11. Two-loop statsum of superstring

    International Nuclear Information System (INIS)

    Morozov, A.

    1987-01-01

    It is discussed, whether there is a choice of odd moduli on super-Riemnann surfaces of genus p ≥ 2, which leads to vanishing of statistical sums of of superstrings before integration over the space of even moduli. The answer is shown to be positive at least for p=2, when odd moduli are localized at ramification points. relation between various definitions of many-lopp statistical sums in superstring theory is discussed

  12. Two-loop superstring partition function

    International Nuclear Information System (INIS)

    Morozov, A.Y.

    1988-01-01

    Is it possible to choose the odd moduli on super-Riemann surfaces of genus p≥2 in such a way that the corresponding contributions to the superstring partition function vanish before the integration over the space of the moduli? It is shown that, at least for p = 2, the answer to this question is affirmative, and in this case the odd moduli should be localized at branch points

  13. Two loop diagrams in Yang Mills theory

    International Nuclear Information System (INIS)

    Jones, D.R.T.

    1974-01-01

    A calculation of the renormalization constants of the Yang Mills field to 0(g 4 ) is presented. The function β(g) is hence evaluated to 0(g 5 ) and possible implications for gauge theories of the strong interactions discussed

  14. Pharmacological effects and potential therapeutic targets of DT-13.

    Science.gov (United States)

    Khan, Ghulam Jilany; Rizwan, Mohsin; Abbas, Muhammad; Naveed, Muhammad; Boyang, Yu; Naeem, Muhammad Ahsan; Khan, Sara; Yuan, Shengtao; Baig, Mirza Muhammad Faran Ashraf; Sun, Li

    2018-01-01

    DT-13 is an isolated compound from Dwarf lillytruf tuber and currently among active research drugs by National Natural Science foundation of China for its several potential effects. The drug has been reported for its multiple pharmacological actions however no thorough review studies are available on it. Our present study is highlighting the pros and cons of DT-13 focusing on its potential pharmacological actions, therapeutic utilization and further exploration for novel targets. The drug possesses very low toxicity profile, quick onset and long duration of action with slow elimination that combinely makes it favorable for the clinical studies. In vivo and in vitro studies show that the drug regulates multiple cellular functions for its several pharmacological effects including, anti-adhesive effects via regulation of tissue factor and transforming growth factor; anti-migratory effects through indirect regulation of NM-IIA in the tumor microenvironment, Tissue factor, down-regulation of CCR5-CCL5 axis and MMP-2/9 inhibition; anti-metastatic effects via regulation of MMPs and tissue factor; pro-apoptotic effects by modulation of endocytosis of EGF receptor; anti-angiogenic effects via regulation of HIF-1α,ERK, Akt signalling and autophagy inducing characteristics by regulating PI3K/Akt/mTOR signalling pathway. In addition to anti-tumor activities, DT-13 has significant anti-inflammatory, cardioprotective, hepatoprotective and immunomodulating effects. Pharmaceutical dosage form and targeted drug delivery system for DT-13 has not been established yet. Moreover, DT-13, has not been studied for its action on brain, colorectal, hepatic, pancreatic, prostate and blood cancers. Similarly the effects of drug on carbohydrate and glucose metabolism is another niche yet to be explored. In some traditional therapies, crude drug from the plant is used against diabetic and neurological disorders that are not reported in scientific literature, however due to profound effects of

  15. Brain potentials associated with the outcome processing in framing effects.

    Science.gov (United States)

    Ma, Qingguo; Feng, Yandong; Xu, Qing; Bian, Jun; Tang, Huixian

    2012-10-24

    Framing effect is a cognitive bias referring to the phenomenon that people respond differently to different but objectively equivalent descriptions of the same problem. By measuring event-related potentials, the present study aimed to investigate the neural mechanisms underlying the framing effect, especially how the negative and positive frames influence the outcome processing in our brain. Participants were presented directly with outcomes framed either positively in terms of lives saved or negatively in terms of lives lost in large and small group conditions, and were asked to rate the favorableness of each of them. The behavioral results showed that the framing effect occurred in both group size conditions, with more favorable evaluations associated with positive framing. Compared with outcomes in positive framing condition, a significant feedback-related negativity (FRN) effect was elicited by outcomes in negative framing condition, even though the outcomes in different conditions were objectively equivalent. The results are explained in terms of the associative model of attribute framing effect which states that attribute framing effect occurs as a result of a valence-based associative processing. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Electronic Polarizability and the Effective Pair Potentials of Water

    Science.gov (United States)

    Leontyev, I. V.; Stuchebrukhov, A. A.

    2014-01-01

    Employing the continuum dielectric model for electronic polarizability, we have developed a new consistent procedure for parameterization of the effective nonpolarizable potential of liquid water. The model explains the striking difference between the value of water dipole moment μ~3D reported in recent ab initio and experimental studies with the value μeff~2.3D typically used in the empirical potentials, such as TIP3P or SPC/E. It is shown that the consistency of the parameterization scheme can be achieved if the magnitude of the effective dipole of water is understood as a scaled value μeff=μ∕εel, where εel =1.78 is the electronic (high-frequency) dielectric constant of water, and a new electronic polarization energy term, missing in the previous theories, is included. The new term is evaluated by using Kirkwood - Onsager theory. The new scheme is fully consistent with experimental data on enthalpy of vaporization, density, diffusion coefficient, and static dielectric constant. The new theoretical framework provides important insights into the nature of the effective parameters, which is crucial when the computational models of liquid water are used for simulations in different environments, such as proteins, or for interaction with solutes. PMID:25383062

  17. Structure of the effective potential for a spherical wormhole

    International Nuclear Information System (INIS)

    Montelongo Garcia, N.; Zannias, T.

    2008-01-01

    The structure of the effective potential V describing causal geodesics near the throat of an arbitrary spherical wormhole is analyzed. Einstein's equations relative to a set of regular coordinates covering a vicinity of the throat imply that any spherical wormhole can be constructed from solutions of an effective initial value problem with the throat serving as an initial value surface. The initial data involve matter variables, the area A(0) of the throat, and the gradient Λ(0) of the redshift factor on the throat. Whenever Λ(0)=0, the effective potential V has a critical point on the throat. Conditions upon the data are derived ensuring that the critical point is a local minimum (respectively maximum). For particular families of quasi-Schwarzschild wormholes, V exhibits a local minimum on the throat independently upon the energy E and angular momentum L 2 of the test particles and thus such wormholes admit stable circular timelike and null geodesics on the throat. For families of Chaplygin wormholes, we show that such geodesics are unstable. Based on a suitable power series representation of the metric, properties of V away from the throat are obtained that are useful for the analysis of accretion disks and radiation processes near the throat of any spherical wormhole.

  18. The RG-improved Twin Higgs effective potential at NNLL

    Energy Technology Data Exchange (ETDEWEB)

    Greco, Davide; Mimouni, Kin [Institut de Théorie des Phénomènes Physiques, EPFL,Route de la Sorge, Lausanne, CH-1015 (Switzerland)

    2016-11-18

    We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of M{sub H}∼120 GeV with an ultraviolet cut-off m{sub ∗}∼10–20 TeV. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through running effects.

  19. The Potential Cost-Effectiveness of Amblyopia Screening Programs

    Science.gov (United States)

    Rein, David B.; Wittenborn, John S.; Zhang, Xinzhi; Song, Michael; Saaddine, Jinan B.

    2013-01-01

    Background To estimate the incremental cost-effectiveness of amblyopia screening at preschool and kindergarten, we compared the costs and benefits of 3 amblyopia screening scenarios to no screening and to each other: (1) acuity/stereopsis (A/S) screening at kindergarten, (2) A/S screening at preschool and kindergarten, and (3) photoscreening at preschool and A/S screening at kindergarten. Methods We programmed a probabilistic microsimulation model of amblyopia natural history and response to treatment with screening costs and outcomes estimated from 2 state programs. We calculated the probability that no screening and each of the 3 interventions were most cost-effective per incremental quality-adjusted life year (QALY) gained and case avoided. Results Assuming a minimal 0.01 utility loss from monocular vision loss, no screening was most cost-effective with a willingness to pay (WTP) of less than $16,000 per QALY gained. A/S screening at kindergarten alone was most cost-effective between a WTP of $17,000 and $21,000. A/S screening at preschool and kindergarten was most cost-effective between a WTP of $22,000 and $75,000, and photoscreening at preschool and A/S screening at kindergarten was most cost-effective at a WTP greater than $75,000. Cost-effectiveness substantially improved when assuming a greater utility loss. All scenarios were cost-effective when assuming a WTP of $10,500 per case of amblyopia cured. Conclusions All 3 screening interventions evaluated are likely to be considered cost-effective relative to many other potential public health programs. The choice of screening option depends on budgetary resources and the value placed on monocular vision loss prevention by funding agencies. PMID:21877675

  20. Effective potential in ultraviolet completions for composite Higgs models

    Science.gov (United States)

    Golterman, Maarten; Shamir, Yigal

    2018-05-01

    We consider a class of composite Higgs models based on asymptotically free S O (d ) gauge theories with d odd, with fermions in two irreducible representations, and in which the Higgs field arises as a pseudo-Nambu-Goldstone boson and the top quark is partially composite. The Nambu-Goldstone coset containing the Higgs field, or Higgs coset, is either S U (4 )/S p (4 ) or S U (5 )/S O (5 ), whereas the top partners live in two-index representations of the relevant flavor group [S U (4 ) or S U (5 )]. In both cases, there is a large number of terms in the most general four-fermion Lagrangian describing the interaction of third-generation quarks with the top partners. We derive the top-induced effective potential for the Higgs coset together with the singlet pseudo-Nambu-Goldstone boson associated with the non-anomalous axial symmetry, to leading order in the couplings between the third-generation quarks and the composite sector. We obtain expressions for the low-energy constants in terms of top-partner two-point functions. We revisit the effective potential of another composite Higgs model that we have studied previously, which is based on an S U (4 ) gauge theory and provides a different realization of the S U (5 )/S O (5 ) coset. The top partners of this model live in the fundamental representation of S U (5 ), and, as a result, the effective potential of this model is qualitatively different from the S O (d ) gauge theories. We also discuss the role of the isospin-triplet fields contained in the S U (5 )/S O (5 ) coset, and show that, without further constraints on the four-fermion couplings, an expectation value for the Higgs field will trigger the subsequent condensation of an isospin-triplet field.

  1. Potentiating Effects of Lactuca sativa on Pentobarbital-Induced Sleep.

    Science.gov (United States)

    Ghorbani, Ahmad; Rakhshandeh, Hassan; Sadeghnia, Hamid Reza

    2013-01-01

    Traditionally, Lactuca sativa (lettuce) has been recommended for its hypnotic property. The present study was planned to investigate sleep-prolonging effect of this plant. The hydro-alcoholic extract (HAE) of lettuce and its water fraction (WF), ethyl acetate fraction (EAF), and n-butanol fraction (NBF) were administrated (IP) to mice 30 min before the pentobarbital injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction which could increase the sleep duration and decrease sleep latency. The effects of NBF were comparable to those of induced by diazepam. The LD50-value for HAE was found to be 4.8 g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12 neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without major toxic effect. The main component(s) responsible for this effect is most likely to be non-polar agent(s) which found in NBF of this plant.

  2. Potential environmental effects of energy conservation measures in northwest industries

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, M C; Gygi, K F; Hendrickson, P L

    1992-01-01

    The Bonneville Power Administration (Bonneville) has identified 101 plants in the Pacific Northwest that account for 80% of the region's industrial electricity consumption. These plants offer a precise target for a conservation program. PNL determined that most of these 101 plants were represented by 11 major industries. We then reviewed 36 major conservation technologies used in these 11 industrial settings to determine their potential environmental impacts. Energy efficiency technologies designed for industrial use may result in direct or indirect environmental impacts. Effects may result from the production of the conservation measure technology, changes in the working environment due to different energy and material requirements, or changes to waste streams. Industry type, work-place conditions, worker training, and environmental conditions inside and outside the plant are all key variables that may affect environmental outcomes. To address these issues this report has three objectives: Describe potential conservation measures that Bonneville may employ in industrial programs and discuss potential primary impacts. Characterize industrial systems and processes where the measure may be employed and describe general environmental issues associated with each industry type. Review environmental permitting, licensing, and other regulatory actions required for industries and summarize the type of information available from these sources for further analysis.

  3. Bioavailability, metabolism and potential health protective effects of dietary flavonoids

    DEFF Research Database (Denmark)

    Bredsdorff, Lea

    Dietary flavonoids constitute an important group of potential health protective compounds from fruits, vegetables, and plant-based products such as tea and wine. The beneficial effects of a diet high in flavonoids on the risk of coronary heart disease (CHD) have been shown in several...... epidemiological studies but the evidence is inconclusive. One major obstacle for epidemiological studies investigating associations between flavonoid intake and risk of CHD is the estimation of flavonoid intake. There is a vast variety of flavonoids in commonly eaten food products but only limited knowledge...... of their content. In addition, variation in individual metabolic genotype and microflora may greatly affect the actual flavonoid exposure. The preventive effects of flavonoids on CHD are mainly ascribed to their anti-inflammatory and antioxidant activities. Several mechanisms of anti-inflammatory and antioxidant...

  4. Effective potentials for supersymmetric three-scale hierarchies

    International Nuclear Information System (INIS)

    Polchinski, J.

    1983-01-01

    We consider the effective potential in models in which supersymmetry breaks at a scale μ but the Goldstone fermion couples only to fields of mass M>>μ. We show that all large perturbative logarithms are removed by taking the renormalization point to be O(M). This makes it possible to calculate the effective potential at large X in those inverted-hierarchy models where the Goldstone fermion couples only to superheavy fields. A general formula for the one-loop logarithm in these models is given. We illustrate the results with an SU(n) example in which the direction as well as the magnitude of the gauge symmetry breaking is undetermined at the tree level. For this example a large perturbative hierarchy does not form and the unbroken subgroup is always SU(n-1) x U(1). In an appendix we show that O'Raifeartaigh models with just one undetermined scalar field always have a decoupled Goldstone fermion when the undetermined field is large, but that this need not be true in more general inverted-hierarchy models

  5. Menthol's potential effects on nicotine dependence: a tobacco industry perspective.

    Science.gov (United States)

    Yerger, Valerie B

    2011-05-01

    To examine what the tobacco industry knows about the potential effects menthol may have on nicotine dependence. A snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu/) between 22 February and 29 April, 2010. Of the approximately 11 million documents available in the Legacy Tobacco Documents Library, the iterative searches returned tens of thousands of results. We qualitatively analysed a final collection of 309 documents relevant the effects of menthol on nicotine dependence. The tobacco industry knows that menthol overrides the harsh taste of tobacco and alleviates nicotine's irritating effects, synergistically interacts with nicotine, stimulates the trigeminal nerve to elicit a 'liking' response for a tobacco product, and makes low tar, low nicotine tobacco products more acceptable to smokers than non-mentholated low delivery products. Menthol is not only used in cigarettes as a flavour additive; tobacco companies know that menthol also has sensory effects and interacts with nicotine to produce tobacco products that are easier to smoke, thereby making it easier to expose smokers, especially those who are new and uninitiated, to the addictive power of nicotine.

  6. Characterization of air freshener emission: the potential health effects.

    Science.gov (United States)

    Kim, Sanghwa; Hong, Seong-Ho; Bong, Choon-Keun; Cho, Myung-Haing

    2015-01-01

    Air freshener could be one of the multiple sources that release volatile organic compounds (VOCs) into the indoor environment. The use of these products may be associated with an increase in the measured level of terpene, such as xylene and other volatile air freshener components, including aldehydes, and esters. Air freshener is usually used indoors, and thus some compounds emitted from air freshener may have potentially harmful health impacts, including sensory irritation, respiratory symptoms, and dysfunction of the lungs. The constituents of air fresheners can react with ozone to produce secondary pollutants such as formaldehyde, secondary organic aerosol (SOA), oxidative product, and ultrafine particles. These pollutants then adversely affect human health, in many ways such as damage to the central nervous system, alteration of hormone levels, etc. In particular, the ultrafine particles may induce severe adverse effects on diverse organs, including the pulmonary and cardiovascular systems. Although the indoor use of air freshener is increasing, deleterious effects do not manifest for many years, making it difficult to identify air freshener-associated symptoms. In addition, risk assessment recognizes the association between air fresheners and adverse health effects, but the distinct causal relationship remains unclear. In this review, the emitted components of air freshener, including benzene, phthalate, and limonene, were described. Moreover, we focused on the health effects of these chemicals and secondary pollutants formed by the reaction with ozone. In conclusion, scientific guidelines on emission and exposure as well as risk characterization of air freshener need to be established.

  7. Psychological theory and pedagogical effectiveness: the learning promotion potential framework.

    Science.gov (United States)

    Tomlinson, Peter

    2008-12-01

    After a century of educational psychology, eminent commentators are still lamenting problems besetting the appropriate relating of psychological insights to teaching design, a situation not helped by the persistence of crude assumptions concerning the nature of pedagogical effectiveness. To propose an analytical or meta-theoretical framework based on the concept of learning promotion potential (LPP) as a basis for understanding the basic relationship between psychological insights and teaching strategies, and to draw out implications for psychology-based pedagogical design, development and research. This is a theoretical and meta-theoretical paper relying mainly on conceptual analysis, though also calling on psychological theory and research. Since teaching consists essentially in activity designed to promote learning, it follows that a teaching strategy has the potential in principle to achieve particular kinds of learning gains (LPP) to the extent that it embodies or stimulates the relevant learning processes on the part of learners and enables the teacher's functions of on-line monitoring and assistance for such learning processes. Whether a teaching strategy actually does realize its LPP by way of achieving its intended learning goals depends also on the quality of its implementation, in conjunction with other factors in the situated interaction that teaching always involves. The core role of psychology is to provide well-grounded indication of the nature of such learning processes and the teaching functions that support them, rather than to directly generate particular ways of teaching. A critically eclectic stance towards potential sources of psychological insight is argued for. Applying this framework, the paper proposes five kinds of issue to be attended to in the design and evaluation of psychology-based pedagogy. Other work proposing comparable ideas is briefly reviewed, with particular attention to similarities and a key difference with the ideas of Oser

  8. Molecular ordering at electrified interfaces: Template and potential effects

    Directory of Open Access Journals (Sweden)

    Thanh Hai Phan

    2014-09-01

    Full Text Available A combination of cyclic voltammetry and in situ scanning tunneling microscopy was employed to examine the adsorption and phase transition of 1,1’-dibenzyl-4,4’-bipyridinium molecules (abbreviated as DBV2+ on a chloride-modified Cu(111 electrode surface. The cyclic voltammogram (CV of the Cu(111 electrode exposed to a mixture of 10 mM HCl and 0.1 mM DBVCl2 shows three distinguishable pairs of current waves P1/P’1, P2/P’2, and P3/P’3 which are assigned to two reversible electron transfer steps, representing the reduction of the dicationic DBV2+ to the corresponding radical monocationic DBV+• (P1/P’1 and then to the uncharged DBV0 (P3/P’3 species, respectively, as well as the chloride desorption/readsorption processes (P2/P’2. At positive potentials (i.e., above P1 the DBV2+ molecules spontaneously adsorb and form a highly ordered phase on the c(p × √3-precovered Cl/Cu(111 electrode surface. A key element of this DBV2+ adlayer is an assembly of two individual DBV2+ species which, lined up, forms a so-called “herring-bone” structure. Upon lowering the electrode potential the first electron transfer step (at P1 causes a phase transition from the DBV2+-related herring-bone phase to the so-called "alternating stripe" pattern built up by the DBV+• species following a nucleation and growth mechanism. Comparison of both observed structures with those found earlier at different electrode potentials on a c(2 × 2Cl-precovered Cu(100 electrode surface enables a clear assessment of the relative importance of adsorbate–substrate and adsorbate–adsorbate interactions, i.e., template vs self-assembly effects, in the structure formation process of DBV cations on these modified Cu electrode surfaces.

  9. Potential harmful effects of dietary supplements in sports medicine.

    Science.gov (United States)

    Deldicque, Louise; Francaux, Marc

    2016-11-01

    The purpose of this article is to collect the most recent data regarding the safety of well-known or emerging dietary supplements used by athletes. From January 2014 to April 2016, about 30 articles have been published in the field. New data show that 90% of sports supplements contain trace of estrogenic endocrine disruptors, with 25% of them having a higher estrogenic activity than acceptable. About 50% of the supplements are contaminated by melamine, a source of nonprotein nitrogen. Additional data accumulate toward the safety of nitrate ingestion. In the last 2 years, the safety of emerging supplements such as higenamine, potentially interesting to lose weight, creatine nitrate and guanidinoacetic acid has been evaluated but still needs further investigation. The consumption of over-the-counter supplements is very popular in athletes. Although most supplements may be considered as safe when taking at the recommended doses, athletes should be aware of the potential risks linked to the consumption of supplements. In addition to the risks linked to overdosage and cross-effects when combining different supplements at the same time, inadvertent or deliberate contamination with stimulants, estrogenic compounds, diuretics or anabolic agents may occur.

  10. One-loop potential with scale invariance and effective operators

    CERN Document Server

    Ghilencea, D M

    2016-01-01

    We study quantum corrections to the scalar potential in classically scale invariant theories, using a manifestly scale invariant regularization. To this purpose, the subtraction scale $\\mu$ of the dimensional regularization is generated after spontaneous scale symmetry breaking, from a subtraction function of the fields, $\\mu(\\phi,\\sigma)$. This function is then uniquely determined from general principles showing that it depends on the dilaton only, with $\\mu(\\sigma)\\sim \\sigma$. The result is a scale invariant one-loop potential $U$ for a higgs field $\\phi$ and dilaton $\\sigma$ that contains an additional {\\it finite} quantum correction $\\Delta U(\\phi,\\sigma)$, beyond the Coleman Weinberg term. $\\Delta U$ contains new, non-polynomial effective operators like $\\phi^6/\\sigma^2$ whose quantum origin is explained. A flat direction is maintained at the quantum level, the model has vanishing vacuum energy and the one-loop correction to the mass of $\\phi$ remains small without tuning (of its self-coupling, etc) bey...

  11. The effect of automatic blink correction on auditory evoked potentials.

    Science.gov (United States)

    Korpela, Jussi; Vigário, Ricardo; Huotilainen, Minna

    2012-01-01

    The effects of blink correction on auditory event-related potential (ERP) waveforms is assessed. Two blink correction strategies are compared. ICA-SSP combines independent component analysis (ICA) with signal space projection (SSP) and ICA-EMD uses empirical mode decomposition (EMD) to improve the performance of the standard ICA method. Five voluntary subjects performed an auditory oddball task. The resulting ERPs are used to compare the two blink correction methods to each other and against blink rejection. The results suggest that both methods qualitatively preserve the ERP waveform but that they underestimate some of the peak amplitudes. ICA-EMD performs slightly better than ICA-SSP. In conclusion, the use of blink correction is justified, especially if blink rejection leads to severe data loss.

  12. Thermal phase transition with full 2-loop effective potential

    Science.gov (United States)

    Laine, M.; Meyer, M.; Nardini, G.

    2017-07-01

    Theories with extended Higgs sectors constructed in view of cosmological ramifications (gravitational wave signal, baryogenesis, dark matter) are often faced with conflicting requirements for their couplings; in particular those influencing the strength of a phase transition may be large. Large couplings compromise perturbative studies, as well as the high-temperature expansion that is invoked in dimensionally reduced lattice investigations. With the example of the inert doublet extension of the Standard Model (IDM), we show how a resummed 2-loop effective potential can be computed without a high-T expansion, and use the result to scrutinize its accuracy. With the exception of Tc, which is sensitive to contributions from heavy modes, the high-T expansion is found to perform well. 2-loop corrections weaken the transition in IDM, but they are moderate, whereby a strong transition remains an option.

  13. Effective potential kinetic theory for strongly coupled plasmas

    Science.gov (United States)

    Baalrud, Scott D.; Daligault, Jérôme

    2016-11-01

    The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

  14. Microbiota and neurologic diseases: potential effects of probiotics.

    Science.gov (United States)

    Umbrello, Giulia; Esposito, Susanna

    2016-10-19

    The microbiota colonizing the gastrointestinal tract have been associated with both gastrointestinal and extra-gastrointestinal diseases. In recent years, considerable interest has been devoted to their role in the development of neurologic diseases, as many studies have described bidirectional communication between the central nervous system and the gut, the so-called "microbiota-gut-brain axis". Considering the ability of probiotics (i.e., live non-pathogenic microorganisms) to restore the normal microbial population and produce benefits for the host, their potential effects have been investigated in the context of neurologic diseases. The main aims of this review are to analyse the relationship between the gut microbiota and brain disorders and to evaluate the current evidence for the use of probiotics in the treatment and prevention of neurologic conditions. Overall, trials involving animal models and adults have reported encouraging results, suggesting that the administration of probiotic strains may exert some prophylactic and therapeutic effects in a wide range of neurologic conditions. Studies involving children have mainly focused on autism spectrum disorder and have shown that probiotics seem to improve neuro behavioural symptoms. However, the available data are incomplete and far from conclusive. The potential usefulness of probiotics in preventing or treating neurologic diseases is becoming a topic of great interest. However, deeper studies are needed to understand which formulation, dosage and timing might represent the optimal regimen for each specific neurologic disease and what populations can benefit. Moreover, future trials should also consider the tolerability and safety of probiotics in patients with neurologic diseases.

  15. Two-loop master integrals for the leading QCD corrections to the Higgs coupling to a W pair and to the triple gauge couplings ZWW and γ{sup ∗}WW

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Stefano Di [DESY,Notkestraße 85, D-22607 Hamburg (Germany); Mastrolia, Pierpaolo; Primo, Amedeo [Dipartimento di Fisica ed Astronomia, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN - Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Schubert, Ulrich [High Energy Physics Division, Argonne National Laboratory,Argonne, IL 60439 (United States)

    2017-04-03

    We compute the two-loop master integrals required for the leading QCD corrections to the interaction vertex of a massive neutral boson X{sup 0}, e.g. H,Z or γ{sup ∗}, with a pair of W bosons, mediated by a SU(2){sub L} quark doublet composed of one massive and one massless flavor. All the external legs are allowed to have arbitrary invariant masses. The Magnus exponential is employed to identify a set of master integrals that, around d=4 space-time dimensions, obey a canonical system of differential equations. The canonical master integrals are given as a Taylor series in ϵ=(4−d)/2, up to order four, with coefficients written as combination of Goncharov polylogarithms, respectively up to weight four. In the context of the Standard Model, our results are relevant for the mixed EW-QCD corrections to the Higgs decay to a W pair, as well as to the production channels obtained by crossing, and to the triple gauge boson vertices ZWW and γ{sup ∗}WW.

  16. Two-loop master integrals for the leading QCD corrections to the Higgs coupling to a W pair and to the triple gauge couplings ZWW and γ{sup *}WW

    Energy Technology Data Exchange (ETDEWEB)

    Di Vita, Stefano [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mastrolia, Pierpaolo; Primo, Amedeo [Padova Univ. (Italy). Dipt. di Fisica ed Astronomia; INFN, Padova (Italy); Schubert, Ulrich [Argonne National Laboratory, Argonne, IL (United States). High Energy Physics Div.

    2017-02-15

    We compute the two-loop master integrals required for the leading QCD corrections to the interaction vertex of a massive neutral boson X{sup 0}, e.g. H,Z or γ*, with a pair of W bosons, mediated by a SU(2){sub L} quark doublet composed of one massive and one massless flavor. All the external legs are allowed to have arbitrary invariant masses. The Magnus exponential is employed to identify a set of master integrals that, around d=4 space-time dimensions, obey a canonical system of differential equations. The canonical master integrals are given as a Taylor series in ε=(4-d)/2, up to order four, with coeffcients written as combination of Goncharov polylogarithms, respectively up to weight four. In the context of the Standard Model, our results are relevant for the mixed EW-QCD corrections to the Higgs decay to a W pair, as well as to the production channels obtained by crossing, and to the triple gauge boson vertices ZWW and γ{sup *}WW.

  17. Statin Therapy: Review of Safety and Potential Side Effects.

    Science.gov (United States)

    Ramkumar, Satish; Raghunath, Ajay; Raghunath, Sudhakshini

    2016-11-01

    Hydroxymethyl glutaryl coenzyme A reductase inhibitors, commonly called statins, are some of the most commonly prescribed medications worldwide. Evidence suggests that statin therapy has significant mortality and morbidity benefit for both primary and secondary prevention from cardiovascular disease. Nonetheless, concern has been expressed regarding the adverse effects of long term statin use. The purpose of this article was to review the current medical literature regarding the safety of statins. Major trials and review articles on the safety of statins were identified in a search of the MEDLINE database from 1980 to 2016, which was limited to English articles. Myalgia is the most common side effect of statin use, with documented rates from 1-10%. Rhabdomyolysis is the most serious adverse effect from statin use, though it occurs quite rarely (less than 0.1%). The most common risk factors for statin-related myopathy include hypothyroidism, polypharmacy and alcohol abuse. Derangement in liver function tests is common, affecting up to 1% of patients; however, the clinical significance of this is unknown. Some statin drugs are potentially diabetogenic and the risk appears to increase in those patients on higher doses. Pitavastatin has not been associated with increased risk of diabetes. Statins have not been proven to increase the risk of malignancy, dementia, mood disorders or acute interstitial nephritis. However, statins do have multiple drug interactions, primarily those which interact with the cytochrome p450 enzyme group. Overall, statin drugs appear to be safe for use in the vast majority of patients. However, patients with multiple medical co-morbidities are at increased risk of adverse effects from long-term statin use.

  18. Abuse potential and adverse cognitive effects of mitragynine (kratom).

    Science.gov (United States)

    Yusoff, Nurul H M; Suhaimi, Farah W; Vadivelu, Raja K; Hassan, Zurina; Rümler, Anne; Rotter, Andrea; Amato, Davide; Dringenberg, Hans C; Mansor, Sharif M; Navaratnam, Visweswaran; Müller, Christian P

    2016-01-01

    Mitragynine is the major psychoactive alkaloid of the plant kratom/ketum. Kratom is widely used in Southeast Asia as a recreational drug, and increasingly appears as a pure compound or a component of 'herbal high' preparations in the Western world. While mitragynine/kratom may have analgesic, muscle relaxant and anti-inflammatory effects, its addictive properties and effects on cognitive performance are unknown. We isolated mitragynine from the plant and performed a thorough investigation of its behavioural effects in rats and mice. Here we describe an addictive profile and cognitive impairments of acute and chronic mitragynine administration, which closely resembles that of morphine. Acute mitragynine has complex effects on locomotor activity. Repeated administration induces locomotor sensitization, anxiolysis and conditioned place preference, enhances expression of dopamine transporter- and dopamine receptor-regulating factor mRNA in the mesencephalon. While there was no increase in spontaneous locomotor activity during withdrawal, animals showed hypersensitivity towards small challenging doses for up to 14 days. Severe somatic withdrawal signs developed after 12 hours, and increased level of anxiety became evident after 24 hours of withdrawal. Acute mitragynine independently impaired passive avoidance learning, memory consolidation and retrieval, possibly mediated by a disruption of cortical oscillatory activity, including the suppression of low-frequency rhythms (delta and theta) in the electrocorticogram. Chronic mitragynine administration led to impaired passive avoidance and object recognition learning. Altogether, these findings provide evidence for an addiction potential with cognitive impairments for mitragynine, which suggest its classification as a harmful drug. © 2014 Society for the Study of Addiction.

  19. Effects of water chemistry and potential distribution on electrochemical corrosion potential measurements in 553 K pure water

    International Nuclear Information System (INIS)

    Ishida, Kazushige; Wada, Yoichi; Tachibana, Masahiko; Ota, Nobuyuki; Aizawa, Motohiro

    2013-01-01

    The effects of water chemistry distribution on the potential of a reference electrode and of the potential distribution on the measured potential should be known qualitatively to obtain accurate electrochemical corrosion potential (ECP) data in BWRs. First, the effects of oxygen on a platinum reference electrode were studied in 553 K pure water containing dissolved hydrogen (DH) concentration of 26 - 10 5 μg kg -1 (ppb). The platinum electrode worked in the same way as the theoretical hydrogen electrode under the condition that the molar ratio of DH to dissolved oxygen (DO) was more than 10 and that DO was less than 100 ppb. Second, the effects of potential distribution on the measured potential were studied by using the ECP measurement part without platinum deposition on the surfaces connected to another ECP measurement part with platinum deposition on the surfaces in 553 K pure water containing 100 - 130 ppb of DH or 100 - 130 ppb of DH plus 400 ppb of hydrogen peroxide. Measured potentials for each ECP measurement part were in good agreement with literature data for each surface condition. The lead wire connecting point did not affect the measured potential. Potential should be measured at the nearest point from the reference electrode in which case it will be not affected by either the potential distribution or the connection point of the lead wire in pure water. (author)

  20. Potential of carbon nanotube field effect transistors for analogue circuits

    KAUST Repository

    Hayat, Khizar

    2013-05-11

    This Letter presents a detailed comparison of carbon nanotube field effect transistors (CNFETs) and metal oxide semiconductor field effect transistors (MOSFETs) with special focus on carbon nanotube FET\\'s potential for implementing analogue circuits in the mm-wave and sub-terahertz range. The latest CNFET lithographic dimensions place it at-par with complementary metal oxide semiconductor in terms of current handling capability, whereas the forecasted improvement in the lithography enables the CNFETs to handle more than twice the current of MOSFETs. The comparison of RF parameters shows superior performance of CNFETs with a g m , f T and f max of 2.7, 2.6 and 4.5 times higher, respectively. MOSFET- and CNFET-based inverter, three-stage ring oscillator and LC oscillator have been designed and compared as well. The CNFET-based inverters are found to be ten times faster, the ring oscillator demonstrates three times higher oscillation frequency and CNFET-based LC oscillator also shows improved performance than its MOSFET counterpart.

  1. Potential economic effects of climate change on Finnish agriculture

    Directory of Open Access Journals (Sweden)

    L. KETTUNEN

    2008-12-01

    Full Text Available In the assessment of the economic effects of climate change, changes in returns and costs have to be taken into consideration. Changes in returns are mainly caused by changes in the yield level. Costs are determined by various factors. Harvesting conditions may improve as the temperatures are higher. However, an increasing need for disease and pest control results in higher costs. Various extensive studies have indicated that rising temperatures with the CO2 fertilizing effect increase the crop potential in Finland. From the economic point of view an increase in yield level is highly significant, because the increase in costs remains quite small. A 10% increase in the yield level raises the farm income by about 6%. Because agriculture is supported in many ways either directly or indirectly, the rise in income level may be offset by lowering the support. Consequently, farmers may not benefit from an increase in the yield level, but the benefit will go to the state economy. However, an increase in the yield level resulting from rising temperatures is advantageous to the national economy, regardless of whether the benefit goes to the farmers or to the state.;

  2. Brain-stem evoked potentials and noise effects in seagulls.

    Science.gov (United States)

    Counter, S A

    1985-01-01

    Brain-stem auditory evoked potentials (BAEP) recorded from the seagull were large-amplitude, short-latency, vertex-positive deflections which originate in the eighth nerve and several brain-stem nuclei. BAEP waveforms were similar in latency and configurations to that reported for certain other lower vertebrates and some mammals. BAEP recorded at several pure tone frequencies throughout the seagull's auditory spectrum showed an area of heightened auditory sensitivity between 1 and 3 kHz. This range was also found to be the primary bandwidth of the vocalization output of young seagulls. Masking by white noise and pure tones had remarkable effects on several parameters of the BAEP. In general, the tone- and click-induced BAEP were either reduced or obliterated by both pure tone and white noise maskers of specific signal to noise ratios and high intensity levels. The masking effects observed in this study may be related to the manner in which seagulls respond to intense environmental noise. One possible conclusion is that intense environmental noise, such as aircraft engine noise, may severely alter the seagull's localization apparatus and induce sonogenic stress, both of which could cause collisions with low-flying aircraft.

  3. Potential of carbon nanotube field effect transistors for analogue circuits

    KAUST Repository

    Hayat, Khizar; Cheema, Hammad; Shamim, Atif

    2013-01-01

    This Letter presents a detailed comparison of carbon nanotube field effect transistors (CNFETs) and metal oxide semiconductor field effect transistors (MOSFETs) with special focus on carbon nanotube FET's potential for implementing analogue circuits in the mm-wave and sub-terahertz range. The latest CNFET lithographic dimensions place it at-par with complementary metal oxide semiconductor in terms of current handling capability, whereas the forecasted improvement in the lithography enables the CNFETs to handle more than twice the current of MOSFETs. The comparison of RF parameters shows superior performance of CNFETs with a g m , f T and f max of 2.7, 2.6 and 4.5 times higher, respectively. MOSFET- and CNFET-based inverter, three-stage ring oscillator and LC oscillator have been designed and compared as well. The CNFET-based inverters are found to be ten times faster, the ring oscillator demonstrates three times higher oscillation frequency and CNFET-based LC oscillator also shows improved performance than its MOSFET counterpart.

  4. The potential effect of taurine as a radioprotective agent

    International Nuclear Information System (INIS)

    Sharoud, M.N.M.

    2010-01-01

    People can be exposed to irradiation either external or internal. The potential effects of radiation on health depend in part on the radiation dose delivered and the rate of delivery causing oxidation and free radical formation. The main purpose of the present study was to asses the effect of taurine administration in modulating some biochemical and hematological parameters in female rats exposed to 6 gray γ-irradiation. The data showed in this study that the ionizing γradiation (6 Gy) induced a significant (p<0.05) increment in the levels of serum lipid profile (cholesterol, triglycerides, HDL and LDL) and elevation of cardiac enzyme activities (LDH, CK and AST) and elevation in the activities of serum AST , ALT and ALP. on the other hand , the ionizing radiation induced a significant (p < 0.05) decline in the concentrations of serum total protein and albumin . In case of exposing female rat to gamma ray, the level of MDA was significantly elevated compared to their corresponding normal control group. Whereas, the drastic decrease were observed in hematological parameters (Hb, RBCs, WBCs and Hct). A significant correction was occurred in all previous parameters after the irradiated rats were intraperitoneally (i.p) injected with taurine (500 mg/100 g body weigh / day for one month). Leading to the conclusion that taurine is considered as antioxidant and a radio-protector agent.

  5. Potential exposures and health effects from spent fuel transportation

    International Nuclear Information System (INIS)

    Sandquist, G.M.; Rogers, V.C.

    1986-01-01

    The radiation exposures and consequent health effects associated with normal operations and accidents during transportation of spent fuel have been analyzed and evaluated. This study was performed for the U.S. Department of Energy (DOE) as contributory data for response to specific public inquires regarding the Draft Environmental Assessments issued by DOE in 1984. Large quantities of spent fuel from power reactors will be shipped by truck and/or rail from the site of generation or temporary storage to nuclear waste repositories. This transportation activity has the potential for increasing radiation exposures and risks above normal background levels in the vicinity of the transportation route. For normal, accident-free transport of spent fuel, radiation exposures arise from both gamma and neutron sources within the spent fuel cask. U.S. regulations limit the radiation dose equivalent rate to 10 millirem per hour at any point 2 meters from the outer lateral surfaces of the transport vehicle. Computer program PATHRAE-T was developed and employed to determine the total, combined dose field. PATHRAE-T was used to estimate the maximum individual doses from rail cask accidents. The maximum individual exposure, primarily due to inhalation, is about 10 rem and occurs about 70 meters downwind. Ground deposited nuclides account for 99 percent of the population dose. The maximum population dose accident could result in about 22 latent health effects for the urban population. The same case rail cask accidents were also evaluated for a maximum water pathway contamination scenario. The nuclide contaminated plume was assumed to be transported over a large reservoir used for domestic and agricultural water. This accident could result in a 63,000 person-rem dose causing about 13 latent health effects in the absence of any natural and industrial processes for nuclide removal from the water

  6. Potential environmental effects of fusion reactor power plants

    International Nuclear Information System (INIS)

    Young, J.R.; Gore, B.F.; Coffman, F.E.

    1976-01-01

    Construction and operation of fusion power plants is expected to reduce the total environmental effects of 21st century power generation. Fusion power plant impacts due to noise, odors, vibrations, and sanitary wastes are expected to be insignificant. impacts due to land use, chemical releases, and aesthetics are expected to be reduced. Impacts due to heat releases, local socio-economic changes, and non-radioactive liquid and solid disposal are expected to be comparable to those for the alternative fission or coal-fired power systems. Radiation doses to the public due to radioactive wastes are expected to be comparable to, or less than, the trivial low doses due to fission power systems. Research and development will be required, however, to assure adequate containment of tritium, the primary radioisotope of concern. Prevention of accidental tritium releases is within the capability of current engineering practice. Current technology is capable of handling the solid radioactive waste which may be produced, with insignificant environmental impact. Major research efforts are necessary to determine if subtle long-term effects of magnetic fields exist and should be of concern. In view of the large quantities of construction materials required for fusion. Material availability may dictate 21st century power plant design and construction. The accident potential of fusion power plants should be lower than for fission systems. Accidental criticalities and plasma runaways are not considered to be possible. Loss of coolant accidents are not expected to result in damage to the containment. No fission products or actinides are present to be released in an accident, and most activation products are immobilized in structures. The biological hazard of tritium is orders of magnitude smaller than for fission products and actinides. Safeguards against diversion of fissile materials are not expected to be necessary

  7. Potential Health Effects of Enzymatic Protein Hydrolysates from Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Mahsa Sedighi

    2016-06-01

    Full Text Available Background and Objective: Chlorella vulgaris is a multi-cellular edible algal species with abundant proteins. Extraction of high value protein fractions for pharmaceutical and nutritional applications can significantly increase the commercial value of microalga biomasses. There is no known report on the anticancer peptides derived from the Chlorella vulgaris abundant protein.Materials and Methods: This study examined the antimicrobial and anticancer effects of peptides from a hydrolyzed Chlorella vulgaris protein with 62 kDa molecular weight. Protein hydrolysis was done by pepsin as a gastrointestinal protease, and was monitored through protein content measurement, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and high performance liquidchromatography measurements. Inhibitory effect of the produced peptides on Escherichia coli cells and breast cancer cell lines was assayed.Results and Conclusion: Hydrolyzed peptides induced a decrease of about 34.1% in the growth of Escherichia coli, and the peptides of 3 to 5 kDa molecular weight had strong impact on the viability of breast cancer cells with IC50 value of 50 μg μl-1. The peptide fractions demonstrating antimicrobial and anti-cancer activities have the potential for use as functional food ingredients for health benefits. These results demonstrate that inexpensive algae proteinscould be a new alternative to produce anticancer peptides.Conflict of interest: The authors declare that there is no conflict of interest.

  8. Investigations on potential co-mutagenic effects of formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Speit, Günter, E-mail: guenter.speit@uni-ulm.de; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

    2014-02-15

    Highlights: • A549 cells were exposed to formaldehyde in combination with various mutagens. • Formaldehyde did not affect the induction and removal of DNA damage (comet assay). • Formaldehyde did not affect the induction of micronuclei by the mutagens tested. • The expression of the O{sup 6}-methylguanine-DNA methyltransferase was not affected. - Abstract: The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10–75 μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O{sup 6}-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

  9. Potential Effects of Horizontal Gene Exchange in the Human Gut.

    Science.gov (United States)

    Lerner, Aaron; Matthias, Torsten; Aminov, Rustam

    2017-01-01

    Many essential functions of the human body are dependent on the symbiotic microbiota, which is present at especially high numbers and diversity in the gut. This intricate host-microbe relationship is a result of the long-term coevolution between the two. While the inheritance of mutational changes in the host evolution is almost exclusively vertical, the main mechanism of bacterial evolution is horizontal gene exchange. The gut conditions, with stable temperature, continuous food supply, constant physicochemical conditions, extremely high concentration of microbial cells and phages, and plenty of opportunities for conjugation on the surfaces of food particles and host tissues, represent one of the most favorable ecological niches for horizontal gene exchange. Thus, the gut microbial system genetically is very dynamic and capable of rapid response, at the genetic level, to selection, for example, by antibiotics. There are many other factors to which the microbiota may dynamically respond including lifestyle, therapy, diet, refined food, food additives, consumption of pre- and probiotics, and many others. The impact of the changing selective pressures on gut microbiota, however, is poorly understood. Presumably, the gut microbiome responds to these changes by genetic restructuring of gut populations, driven mainly via horizontal gene exchange. Thus, our main goal is to reveal the role played by horizontal gene exchange in the changing landscape of the gastrointestinal microbiome and potential effect of these changes on human health in general and autoimmune diseases in particular.

  10. Potential Therapeutic Effects of Meditation for Treating Affective Dysregulation

    Directory of Open Access Journals (Sweden)

    Natalie T. Y. Leung

    2014-01-01

    Full Text Available Affective dysregulation is at the root of many psychopathologies, including stress induced disorders, anxiety disorders, and depression. The root of these disorders appears to be an attenuated, top-down cognitive control from the prefrontal cortices over the maladaptive subcortical emotional processing. A form of mental training, long-term meditation practice can trigger meditation-specific neuroplastic changes in the brain regions underlying cognitive control and affective regulation, suggesting that meditation can act as a kind of mental exercise to foster affective regulation and possibly a cost-effective intervention in mood disorders. Increasing research has suggested that the cultivation of awareness and acceptance along with a nonjudgmental attitude via meditation promotes adaptive affective regulation. This review examined the concepts of affective regulation and meditation and discussed behavioral and neural evidence of the potential clinical application of meditation. Lately, there has been a growing trend toward incorporating the “mindfulness” component into existing psychotherapeutic treatment. Promising results have been observed thus far. Future studies may consider exploring the possibility of integrating the element of “compassion” into current psychotherapeutic approaches.

  11. Effects of discontinuities of the derivatives of the inflaton potential

    Energy Technology Data Exchange (ETDEWEB)

    Cadavid, Alexander Gallego [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Romano, Antonio Enea, E-mail: aer@physics.uoc.gr [Instituto de Fisica, Universidad de Antioquia, A.A.1226, Medellin (Colombia); Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto (Japan); Department of Physics, University of Crete, 71003, Heraklion (Greece)

    2015-12-12

    We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure.

  12. Effects of discontinuities of the derivatives of the inflaton potential

    Energy Technology Data Exchange (ETDEWEB)

    Gallego Cadavid, Alexander [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Enea Romano, Antonio [Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); University of Crete, Department of Physics, Heraklion (Greece)

    2015-12-15

    We study the effects of a class of features of the inflaton potential, corresponding to discontinuities in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature perturbations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k{sub 0} which leaves the horizon at the time τ{sub 0} when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and the equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non-Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure. (orig.)

  13. Effect of practicing yoga on cervical vestibular evoked myogenic potential.

    Science.gov (United States)

    Shambhu, Tejaswini; Kumar, Shubhaganga Dhrruva; Prabhu, Prashanth

    2017-10-01

    The present study attempted to determine the effect of practicing yoga on functioning of sacculo-collic pathway using cervical vestibular evoked myogenic potential (cVEMP). cVEMP was recorded from 40 participants (20 who practice yoga regularly and 20 who do not practice yoga regularly). The differences in amplitude of P1, N1, P1-N1 complex, asymmetry ratio and latencies of P1 and N1 of cVEMP were compared between both the groups. The results of the study showed that there was a significant increase (p yoga was significantly lower (Mean = 6.73) compared to the control group (Mean = 19.13). Multivariate regression analyses suggested that the number of years of yoga practice significantly predicted the amplitude of P1-N1 complex (β = 0.70, p yoga improves postural control and strengthens the muscles and vestibular system leading to enhanced cVEMP responses. The plastic changes in the vestibular system and increased muscular strength because of constant practicing of yoga could have led to changes in cVEMP responses. However, further studies on a larger group of individuals are essential for better clinical applicability of the results.

  14. Potential Effects of Pomegranate Polyphenols in Cancer Prevention and Therapy.

    Science.gov (United States)

    Turrini, Eleonora; Ferruzzi, Lorenzo; Fimognari, Carmela

    2015-01-01

    Cancer is the second leading cause of death and is becoming the leading one in old age. Vegetable and fruit consumption is inversely associated with cancer incidence and mortality. Currently, interest in a number of fruits high in polyphenols has been raised due to their reported chemopreventive and/or chemotherapeutic potential. Pomegranate has been shown to exert anticancer activity, which is generally attributed to its high content of polyphenols. This review provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of pomegranate polyphenols as future anticancer agents. Pomegranate evokes antiproliferative, anti-invasive, and antimetastatic effects, induces apoptosis through the modulation of Bcl-2 proteins, upregulates p21 and p27, and downregulates cyclin-cdk network. Furthermore, pomegranate blocks the activation of inflammatory pathways including, but not limited to, the NF-κB pathway. The strongest evidence for its anticancer activity comes from studies on prostate cancer. Accordingly, some exploratory clinical studies investigating pomegranate found a trend of efficacy in increasing prostate-specific antigen doubling time in patients with prostate cancer. However, the genotoxicity reported for pomegranate raised certain concerns over its safety and an accurate assessment of the risk/benefit should be performed before suggesting the use of pomegranate or its polyphenols for cancer-related therapeutic purposes.

  15. Potential Effects of Horizontal Gene Exchange in the Human Gut

    Directory of Open Access Journals (Sweden)

    Aaron Lerner

    2017-11-01

    Full Text Available Many essential functions of the human body are dependent on the symbiotic microbiota, which is present at especially high numbers and diversity in the gut. This intricate host–microbe relationship is a result of the long-term coevolution between the two. While the inheritance of mutational changes in the host evolution is almost exclusively vertical, the main mechanism of bacterial evolution is horizontal gene exchange. The gut conditions, with stable temperature, continuous food supply, constant physicochemical conditions, extremely high concentration of microbial cells and phages, and plenty of opportunities for conjugation on the surfaces of food particles and host tissues, represent one of the most favorable ecological niches for horizontal gene exchange. Thus, the gut microbial system genetically is very dynamic and capable of rapid response, at the genetic level, to selection, for example, by antibiotics. There are many other factors to which the microbiota may dynamically respond including lifestyle, therapy, diet, refined food, food additives, consumption of pre- and probiotics, and many others. The impact of the changing selective pressures on gut microbiota, however, is poorly understood. Presumably, the gut microbiome responds to these changes by genetic restructuring of gut populations, driven mainly via horizontal gene exchange. Thus, our main goal is to reveal the role played by horizontal gene exchange in the changing landscape of the gastrointestinal microbiome and potential effect of these changes on human health in general and autoimmune diseases in particular.

  16. Photoionization cross section in a spherical quantum dot: Effects of some parabolic confining electric potentials

    Directory of Open Access Journals (Sweden)

    M. Tshipa

    2017-12-01

    Full Text Available A theoretical investigation of the effects of spatial variation of confining electric potential on photoionization cross section (PCS in a spherical quantum dot is presented. The potential profiles considered here are the shifted parabolic potential and the inverse lateral shifted parabolic potential compared with the well-studied parabolic potential. The primary findings are that parabolic potential and the inverse lateral shifted parabolic potential blue shift the peaks of the PCS while the shifted parabolic potential causes a red shift.

  17. Effect of the Potential Shape on the Stochastic Resonance Processes

    Science.gov (United States)

    Kenmoé, G. Djuidjé; Ngouongo, Y. J. Wadop; Kofané, T. C.

    2015-10-01

    The stochastic resonance (SR) induced by periodic signal and white noises in a periodic nonsinusoidal potential is investigated. This phenomenon is studied as a function of the friction coefficient as well as the shape of the potential. It is done through an investigation of the hysteresis loop area which is equivalent to the input energy lost by the system to the environment per period of the external force. SR is evident in some range of the shape parameter of the potential, but cannot be observed in the other range. Specially, variation of the shape potential affects significantly and not trivially the heigh of the potential barrier in the Kramers rate as well as the occurrence of SR. The finding results show crucial dependence of the temperature of occurrence of SR on the shape of the potential. It is noted that the maximum of the input energy generally decreases when the friction coefficient is increased.

  18. An effective pair potential for liquid semiconductor, Se: Structure and ...

    Indian Academy of Sciences (India)

    This model potential is then used to describe through low-order perturbation theory, the structure and related dynamical properties like self-diffusion coefficient and shear viscosity of this complex liquid over a wide range of temperatures. Keywords. Liquid semiconductor; pair potential; structure and dynamical properties.

  19. Immunotherapy Plus Cryotherapy: Potential Augmented Abscopal Effect for Advanced Cancers

    Directory of Open Access Journals (Sweden)

    Joe Abdo

    2018-03-01

    Full Text Available Since the 1920s the gold standard for treating cancer has been surgery, which is typically preceded or followed with chemotherapy and/or radiation, a process that perhaps contributes to the destruction of a patient’s immune defense system. Cryosurgery ablation of a solid tumor is mechanistically similar to a vaccination where hundreds of unique antigens from a heterogeneous population of tumor cells derived from the invading cancer are released. However, releasing tumor-derived self-antigens into circulation may not be sufficient enough to overcome the checkpoint escape mechanisms some cancers have evolved to avoid immune responses. The potentiated immune response caused by blocking tumor checkpoints designed to prevent programmed cell death may be the optimal treatment method for the immune system to recognize these new circulating cryoablated self-antigens. Preclinical and clinical evidence exists for the complementary roles for Cytotoxic T-lymphocyte-associated protein (CTLA-4 and PD-1 antagonists in regulating adaptive immunity, demonstrating that combination immunotherapy followed by cryosurgery provides a more targeted immune response to distant lesions, a phenomenon known as the abscopal effect. We propose that when the host’s immune system has been “primed” with combined anti-CTLA-4 and anti-PD-1 adjuvants prior to cryosurgery, the preserved cryoablated tumor antigens will be presented and processed by the host’s immune system resulting in a robust cytotoxic CD8+ T-cell response. Based on recent investigations and well-described biochemical mechanisms presented herein, a polyvalent autoinoculation of many tumor-specific antigens, derived from a heterogeneous population of tumor cancer cells, would present to an unhindered yet pre-sensitized immune system yielding a superior advantage in locating, recognizing, and destroying tumor cells throughout the body.

  20. Effect of potential steps on porous silicon formation

    International Nuclear Information System (INIS)

    Cheng Xuan; Feng Zude; Luo Guangfeng

    2003-01-01

    Porous silicon microstructures were fabricated by applying potential steps through which both anodic and cathodic potentials were periodically applied to silicon wafers. The electrochemical behaviors of porous silicon layers were examined by performing polarization measurements, followed by analyzing the open-circuit potential (E ocp ) and the reaction rate in terms of corrosion current density (j corr ). The surface morphologies and surface products of porous silicon were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It was found that the values of E ocp and j corr varied more significantly and irregularly during different polarization stages when the potentials were continuously applied to the wafer surface, while virtually unchanged after 2 min of periodic potential application. In addition, slower reaction rates were observed with applying potential steps, as indicated by smaller values of j corr . The enhancement on refreshment of silicon surfaces by periodic potential polarization significantly accelerated the growth of porous silicon. The microstructures became more uniformed and better defined due to the improved passivating nature of wafer surfaces

  1. Potential environmental effects of the leading edge hydrokinetic energy technology.

    Science.gov (United States)

    2017-05-01

    The Volpe Center evaluated potential environmental challenges and benefits of the ARPA-E funded research project, Marine Hydrokinetic Energy Harvesting Using Cyber-Physical Systems, led by Brown University. The Leading Edge research team develo...

  2. Potentiating effect of ecofriendly synthesis of copper oxide ...

    Indian Academy of Sciences (India)

    diseases, however, it necessitates clinical studies to ascertain their potential as antimicrobial and anticancer agents. ... erties would result in interesting new applications of metal .... [13] South G R and Whittick A 1987 Introduction to psychology.

  3. Proprioceptive event related potentials: gating and task effects

    DEFF Research Database (Denmark)

    Arnfred, Sidse M

    2005-01-01

    The integration of proprioception with vision, touch or audition is considered basic to the developmental formation of perceptions, conceptual objects and the creation of cognitive schemes. Thus, mapping of proprioceptive information processing is important in cognitive research. A stimulus...... of a brisk change of weight on a hand held load elicit a proprioceptive evoked potential (PEP). Here this is used to examine early and late information processing related to weight discrimination by event related potentials (ERP)....

  4. [Potential endocrine disrupting effects of bifenthrin in rats].

    Science.gov (United States)

    Tan, Yanjun; Wang, Hengjuan; Song, Yan; Yang, Hui; Jia, Xudong; Li, Ning

    2012-05-01

    To study the potential endocrine disrupting effects of bifenthrin (BIF) by using uterotrophic assay and Hershberger assay. In uterotrophic assay, 60 female SD rats were randomly divided into 6 groups, 10 rats per group. Rats in bifenthrin-treated groups were given different doses of bifenthrin (1.47, 4.41 and 13.23 mg/kg BW by gavage for 3 consecutive days). Rats in negative control groups were given corn oil by gavage. Rats in ethinyl estradiol (EE) oral positive control groups were given EE 1.0 microg/kg BW by gavage. Rats in EE injected positive groups were given 0.6 microg/kg BW EE by subcutaneously injection while given corn oil by gavage. At necropsy, the wet and blotted uteri were weighed. The relative uteri weights were calculated, and the histology of uteri was observed. In Hershberger assay, 60 castrated male SD rats were randomly divided into 6 groups, with 10 rats in each group. Rats in BIF-treated groups were given different doses of BIF (1.4, 4.2 and 12.6 mg/kg BW) by gavage. Flutamide (3.0 mg/kg BW) were given to animals in the positive control group by gavage. Rats in the negative control group and testosterone propionate group were given corn oil by gavage for 10 consecutive days. Rats in all groups except the negative control group were also treated with testosterone propionate (TP, 0.2 mg/kg BW) by subcutaneous injection. At necropsy, ventral prostate (VP), seminal vesicle plus fluids and coagulating glands (SVCG), levator ani-bulbocavernosus muscle (LABC), paired Cowper's glands (COW) and the glands penis (GP), liver, kidneys, adrenals were weighed. Serum triiodothyronine (T3) and thyroxine (T4) were determined. In uterotrophic assay, compared with the negative control group, the mean relative wet weight and relative blotted weight of uterine were increased significantly in the female rats given by BIF at 13.23 mg/kg BW for 3 days (P < 0.05). BIF resulted in a significant increase of epithelial cell heights of uteri at 4.41 and 13.23 mg/kg BW

  5. Superfield approach to calculation of effective potential in supersymmetric field theories

    International Nuclear Information System (INIS)

    Bukhbinder, I.L.; Kuzenko, S.M.; Yarevskaya, Zh.V.

    1993-01-01

    Superfield method of computing effective potential in supersymmetric field theories is suggested. The one-loop effective potential of the Wess-Zumino model is found. The prescription for obtaining multi-loop corrections is described

  6. Effect of Temperature on the Biotic Potential of Honeybee Microsporidia▿

    Science.gov (United States)

    Martín-Hernández, Raquel; Meana, Aránzazu; García-Palencia, Pilar; Marín, Pilar; Botías, Cristina; Garrido-Bailón, Encarna; Barrios, Laura; Higes, Mariano

    2009-01-01

    The biological cycle of Nosema spp. in honeybees depends on temperature. When expressed as total spore counts per day after infection, the biotic potentials of Nosema apis and N. ceranae at 33°C were similar, but a higher proportion of immature stages of N. ceranae than of N. apis were seen. At 25 and 37°C, the biotic potential of N. ceranae was higher than that of N. apis. The better adaptation of N. ceranae to complete its endogenous cycle at different temperatures clearly supports the observation of the different epidemiological patterns. PMID:19233948

  7. Diatomic Molecules Effective Potential for an Harmonic Oscillator ...

    African Journals Online (AJOL)

    A model anharmonic potential was considered and was used in the Schrödinger time independent wave equation to describe a carbon monoxide molecule. Central difference scheme was used in approximating the derivative term in the Schrödinger equation leading to a tri-diagonal band system of equation. The method of ...

  8. Lake Victoria's Water Budget and the Potential Effects of Climate ...

    African Journals Online (AJOL)

    This paper presents the Lake Victoria water budget for the period 1950-2004 and findings of a study on potential climate change impact on the lake's Hydrology through the 21st Century. The mass balance components are computed from measured and simulated data. A2 and B2 emission scenarios of the Special Report ...

  9. Potential effects of earthworms on leaf-chewer performance

    NARCIS (Netherlands)

    Newington, J.E.; Setälä, H.; Bezemer, T.M.; Jones, T.H.

    2004-01-01

    Detritivores affect plant performance and therefore have the potential indirectly to affect above-ground herbivore populations. 2. In a microcosm study we asked whether changes in the performance of two plant species, Cardamine hirsuta L. and Veronica persica Poiret., arising from the activity of

  10. The effect of nonlinearity in relativistic nucleon–nucleon potential

    Indian Academy of Sciences (India)

    2014-04-01

    Apr 1, 2014 ... the popular M3Y form using the relativistic mean field theory (RMFT) with ... are fitted to deuteron properties and available phase shifts. ..... 2.2 Optical potential and the half-lives study using the preformed cluster model (PCM).

  11. Monitoring potential neurotoxic effects of hazardous waste disposal

    OpenAIRE

    Schaumburg, Herbert H.; Spencer, Peter S.; Arezzo, Joseph C.

    1983-01-01

    This report reviews neurotoxicological principles relevant to situations of hazardous waste disposal. Some of the diagnostic techniques currently used for field assessment of nervous system dysfunction are critically evaluated. These include nerve conduction velocity, evoked potentials, neuropsychological testing and use of the Optacon.

  12. Quasielastic electron scattering: effect of relativistic nuclear potentials

    International Nuclear Information System (INIS)

    Do Dang, G.; Nguyen Van Giai.

    1983-11-01

    It is shown that a solution to the difficulty encountered in reproducing simultaneously the experimental longitudinal and transverse response functions deduced from deep inelastic electron scattering may be found in a consistent treatment of the electromagnetic interaction in a Dirac equation in which Lorentz scalar and vector potentials are explicitly introduced. Results for 12 C and 40 Ca are given and compared with experiments

  13. Potential Effects of Domestic Energy on the Health of Women ...

    African Journals Online (AJOL)

    Objective: To highlight the various potential health problems women and others exposed to gases/substances emitted from domestic sources of energy are at risk of. A review of the literature on the health problems associated with use of various forms of energy fuels was done. Review: Not much literature has emanated ...

  14. The effective matter potential for highly relativistic neutrinos

    International Nuclear Information System (INIS)

    Konstandin, Thomas; Ohlsson, Tommy

    2006-01-01

    We investigate matter effects on highly relativistic neutrinos. The self-energy of neutrinos is determined in an electron or neutrino background taking into account resonance and finite width effects of the gauge bosons. We find minor changes compared to the formerly used formula for the propagator function and large deviations of the effective width from the decay width of the gauge bosons considering higher moments of the electron or neutrino distribution function

  15. NLL resummation for the static potential in N=4 SYM theory

    Energy Technology Data Exchange (ETDEWEB)

    Stahlhofen, Maximilian [Wien Univ. (Austria). Fakultaet fuer Physik

    2012-09-15

    We determine the complete NLL running of the static potential associated with the locally 1/2 BPS Wilson loop in N=4 supersymmetric Yang-Mills theory. We present results for the SU(N{sub c}) singlet as well as for the adjoint configuration and arbitrary N{sub c} at weak coupling. In order to derive the respective anomalous dimensions we perform a two-loop calculation in the N=4 supersymmetric version of the effective field theory pNRQCD. In addition we confirm the recently obtained fixed-order result for the singlet static potential generated exclusively by ladder diagrams to the third order in the t'Hooft coupling. We also give an explicit expression for the logarithmic contribution of all non-ladder diagrams at this order.

  16. NLL resummation for the static potential in N=4 SYM theory

    International Nuclear Information System (INIS)

    Stahlhofen, Maximilian

    2012-09-01

    We determine the complete NLL running of the static potential associated with the locally 1/2 BPS Wilson loop in N=4 supersymmetric Yang-Mills theory. We present results for the SU(N c ) singlet as well as for the adjoint configuration and arbitrary N c at weak coupling. In order to derive the respective anomalous dimensions we perform a two-loop calculation in the N=4 supersymmetric version of the effective field theory pNRQCD. In addition we confirm the recently obtained fixed-order result for the singlet static potential generated exclusively by ladder diagrams to the third order in the t'Hooft coupling. We also give an explicit expression for the logarithmic contribution of all non-ladder diagrams at this order.

  17. An interatomic potential model for carbonates allowing for polarization effects

    International Nuclear Information System (INIS)

    Birse, S.E.A.; Archer, T.D.; Dove, Martin T.; Cygan, Randall Timothy; Gale, Julian D.; Redern, Simon A.T.

    2003-01-01

    An empirical model for investigating the behavior of CaCO 3 polymorphs incorporating a shell model for oxygen has been created. The model was constructed by fitting to: the structure of aragonite and calcite; their elastic, static and high-frequency dielectric constants; phonon frequencies at the wave vectors (1/2 0 2) and (0 0 0) of calcite; and vibrational frequencies of the carbonate deformation modes of calcite. The high-pressure phase transition between calcite I and II is observed. The potentials for the CO 3 group were transferred to other carbonates, by refitting the interaction between CO 3 and the cation to both the experimental structures and their bulk modulus, creating a set of potentials for calculating the properties of a wide range of carbonate materials. Defect energies of substitutional cation defects were analyzed for calcite and aragonite phases. The results were rationalized by studying the structure of calcite and aragonite in greater detail.

  18. University students' psychopathology: correlates and the examiner's potential bias effect

    Directory of Open Access Journals (Sweden)

    Helena Espirito Santo

    2015-02-01

    Aims: the main objective was to verify if there is a difference on psychopathological symptoms between two groups questioned by two different examiners, controlling for the potential role of social desirability, and other potential covariates. Additionally, we want to assess the level of psychopathology and its socio-demographic correlates.Methods: 185 Coimbra's university students completed the Brief Symptom Inventory/BSI and the Marlowe-Crowne Social Desirability Scale. In one group the examiner was of the same age and academic status as the students, while in the other group the examiner was older and a teacher. We studied the psychopathological correlates with Pearson, point-biserial correlations, and qui-square analyses, and we controlled the potential role of covariates through Quade non-parametric ANCOVAs. Results: The level of distress was lower in comparison with other investigations. Women had higher level of distress and more symptoms of somatization, anxiety, phobic anxiety, obsessive-compulsion, and depression. The students that live a higher distance from home had more anxiety and obsessive-compulsive symptoms. The group assessed by the younger examiner scored higher in distress and in some BSI factors, and had lower levels on social desirability. Conclusions: Sex and distance from home seem important factors for university students' mental health. However, the examiner does have an influence in the evaluation, probably because of social desirability, suggesting that the examiner's characteristics should be given in investigations involving university students.

  19. Newer Approaches to Identify Potential Untoward Effects in Functional Foods.

    Science.gov (United States)

    Marone, Palma Ann; Birkenbach, Victoria L; Hayes, A Wallace

    2016-01-01

    Globalization has greatly accelerated the numbers and variety of food and beverage products available worldwide. The exchange among greater numbers of countries, manufacturers, and products in the United States and worldwide has necessitated enhanced quality measures for nutritional products for larger populations increasingly reliant on functionality. These functional foods, those that provide benefit beyond basic nutrition, are increasingly being used for their potential to alleviate food insufficiency while enhancing quality and longevity of life. In the United States alone, a steady import increase of greater than 15% per year or 24 million shipments, over 70% products of which are food related, is regulated under the Food and Drug Administration (FDA). This unparalleled growth has resulted in the need for faster, cheaper, and better safety and efficacy screening methods in the form of harmonized guidelines and recommendations for product standardization. In an effort to meet this need, the in vitro toxicology testing market has similarly grown with an anticipatory 15% increase between 2010 and 2015 of US$1.3 to US$2.7 billion. Although traditionally occupying a small fraction of the market behind pharmaceuticals and cosmetic/household products, the scope of functional food testing, including additives/supplements, ingredients, residues, contact/processing, and contaminants, is potentially expansive. Similarly, as functional food testing has progressed, so has the need to identify potential adverse factors that threaten the safety and quality of these products. © The Author(s) 2015.

  20. Analysis of some potential social effects of four coal technologies

    Energy Technology Data Exchange (ETDEWEB)

    Walker, C.A.; Gould, L.C.

    1980-09-01

    This is an analysis of the potential social impacts of four coal technologies: conventional combustion, fluidized-bed combustion, liquifaction, and gasification. Because of their flexibility, and the abundance and relatively low costs of coal, the potential benefits of these technologies would seem to outweigh their potential social costs, both in the intermediate and long term. Nevertheless, the social costs of a coal industry are far more obscure and hard to quantify than the benefits. In general, however, it maybe expected that those technologies that can be deployed most quickly, that provide fuels that can substitute most easily for oil and natural gas, that are the cheapest, and that are the most thermally efficient will minimize social costs most in the intermediate term, while technologies that can guide energy infrastructure changes to become the most compatable with the fuels that will be most easily derived from inexhaustible sources (electricity and hydrogen) will minimize social costs most in the long run. An industry structured to favor eastern over western coal and plant sites in moderate sized communities, which could easily adapt to inexhaustible energy technologies (nuclear or solar) in the future, would be favored in either time period.

  1. Potential effects of nuclear war on agricultural productivity

    International Nuclear Information System (INIS)

    Harwell, M.A.; Cropper, W.P. Jr.

    1985-01-01

    The authors examine the vulnerabilities of agricultural systems to nuclear war-induced climatic perturbations and to other, indirect effects of nuclear war. Discussion is included of the dependency of agricultural production on technological inputs and the effects of loss or reduction of these inputs in a post-nuclear war world

  2. Quantum vacuum effects from boundaries of designer potentials

    NARCIS (Netherlands)

    Konopka, T.J.

    2009-01-01

    Vacuum energy in quantum field theory, being the sum of zero-point energies of all field modes, is formally infinite but yet, after regularization or renormalization, can give rise to finite observable effects. One way of understanding how these effects arise is to compute the vacuum energy in an

  3. Acute and Sub-Chronic Toxicity Potential Effects of Alchornea ...

    African Journals Online (AJOL)

    The open field test showed that sub-chronic administration increased rearing behavior significantly at the dose of 250 mg/kg/28 days but had no effect on grooming. In conclusion, the ethanolic extract has no toxicological effect as observed on hematological, biochemical and histopathological parameters even at the ...

  4. Potential effects on health of radioactive waste disposal

    International Nuclear Information System (INIS)

    Sousselier, Y.; Parmentier, N.

    1983-07-01

    Radioactive waste is considered to represent a potential health risk for future generation by a section of the public. The main point is that waste management must follow very strict guidelines. The radioactive waste treatment, packaging and disposal are rewieved and discussed from a safety point of view. Health physics aspects are then analysed. The major difficulties for the prediction of exposure are mainly due to the very long time periods involved. Models are studied and carried out for the prediction of radiological consequences for the transport of radioactivity through the different modules

  5. Potential Effects of Desalinated Seawater on Arteriosclerosis in Rats.

    Science.gov (United States)

    Duan, Lian; Zhang, Li Xia; Zhang, Shao Ping; Kong, Jian; Zhi, Hong; Zhang, Ming; Lu, Kai; Zhang, Hong Wei

    2017-10-01

    To evaluate the potential risk of arteriosclerosis caused by desalinated seawater, Wistar rats were provided desalinated seawater over a 1-year period, and blood samples were collected at 0, 90, 180, and 360 days. Blood calcium, magnesium, and arteriosclerosis-related indicators were investigated. Female rats treated with desalinated seawater for 180 days showed lower magnesium levels than the control rats (P seawater for 360 days (P seawater, and no increase in risk of arteriosclerosis was observed. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  6. Slow high-frequency effects in mechanics: problems, solutions, potentials

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2005-01-01

    – an apparent change in the stiffness associated with an equilibrium; Biasing – a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening – a tendency for discontinuities to be apparently smeared out by HFE. The effects and a method for analyzing...... and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes by suggesting that more vibration experts, researchers and students should know about HFE effects, for the benefit not only of general vibration troubleshooting, but also......Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening...

  7. Slow high-frequency effects in mechanics: problems, solutions, potentials

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    – an apparent change in the stiffness associated with an equilibrium; Biasing – a tendency for a system to move towards a particular state which does not exist or is unstable without HFE; and Smoothening – a tendency for discontinuities to be apparently smeared out by HFE. The effects and a method for analyzing...... and compared: The Method of Direct Separation of Motions, the Method of Averaging, and the Method of Multiple Scales. The tutorial concludes by suggesting that more vibration experts, researchers and students should know about HFE effects, for the benefit not only of general vibration troubleshooting, but also......Strong high-frequency excitation (HFE) may change the ‘slow’ (i.e. effective or average) properties of mechanical systems, e.g. their stiffness, natural frequencies, equilibriums, equilibrium stability, and bifurcation paths. This tutorial describes three general HFE effects: Stiffening...

  8. Leadership intelligence: Unlocking the potential for school leadership effectiveness

    OpenAIRE

    Gage, Timothy; Smith, Clive

    2016-01-01

    Top performing companies have long used intelligence tests in their selection procedures to predict who the best leaders are. However, no longer are the brightest favoured, or guaranteed success. A post-modern world demands a fresh outlook on leadership. How can school leaders judge their effectiveness? How can school leaders lead intelligently? This article explores a theoretical approach to effective school leadership in an emerging context, which embraces a holistic understanding of intell...

  9. Effective intermolecular potential and critical point for C60 molecule

    Science.gov (United States)

    Ramos, J. Eloy

    2017-07-01

    The approximate nonconformal (ANC) theory is applied to the C60 molecule. A new binary potential function is developed for C60, which has three parameters only and is obtained by averaging the site-site carbon interactions on the surface of two C60 molecules. It is shown that the C60 molecule follows, to a good approximation, the corresponding states principle with n-C8H18, n-C4F10 and n-C5F12. The critical point of C60 is estimated in two ways: first by applying the corresponding states principle under the framework of the ANC theory, and then by using previous computer simulations. The critical parameters obtained by applying the corresponding states principle, although very different from those reported in the literature, are consistent with the previous results of the ANC theory. It is shown that the Girifalco potential does not correspond to an average of the site-site carbon-carbon interaction.

  10. Potential Cost-Effective Opportunities for Methane Emission Abatement

    Energy Technology Data Exchange (ETDEWEB)

    Warner, Ethan [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States); Steinberg, Daniel [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States); Hodson, Elke [U.S. Department of Energy, Washington, DC (United States); Heath, Garvin [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-08-01

    The energy sector was responsible for approximately 84% of carbon dioxide equivalent (CO2e) greenhouse gas (GHG) emissions in the U.S. in 2012 (EPA 2014a). Methane is the second most important GHG, contributing 9% of total U.S. CO2e emissions. A large portion of those methane emissions result from energy production and use; the natural gas, coal, and oil industries produce approximately 39% of anthropogenic methane emissions in the U.S. As a result, fossil-fuel systems have been consistently identified as high priority sectors to contribute to U.S. GHG reduction goals (White House 2015). Only two studies have recently attempted to quantify the abatement potential and cost associated with the breadth of opportunities to reduce GHG emissions within natural gas, oil, and coal supply chains in the United States, namely the U.S. Environmental Protection Agency (EPA) (2013a) and ICF (2014). EPA, in its 2013 analysis, estimated the marginal cost of abatement for non-CO2 GHG emissions from the natural gas, oil, and coal supply chains for multiple regions globally, including the United States. Building on this work, ICF International (ICF) (2014) provided an update and re-analysis of the potential opportunities in U.S. natural gas and oil systems. In this report we synthesize these previously published estimates as well as incorporate additional data provided by ICF to provide a comprehensive national analysis of methane abatement opportunities and their associated costs across the natural gas, oil, and coal supply chains. Results are presented as a suite of marginal abatement cost curves (MACCs), which depict the total potential and cost of reducing emissions through different abatement measures. We report results by sector (natural gas, oil, and coal) and by supply chain segment - production, gathering and boosting, processing, transmission and storage, or distribution - to facilitate identification of which sectors and supply chain

  11. General review on climate change problems: causes, potential effects

    International Nuclear Information System (INIS)

    Martellet, J.

    1991-01-01

    Greenhouse gases and greenhouse effect principles are reviewed and climate changes due to the human activities are discussed: identification of gases, human or natural causes, composition evolution in the atmosphere and relative roles of greenhouse gases. The various tools and calculations methods for evaluating the climate change due to greenhouse effect are presented. Several problems are stated: evolution of the climate structure in 2030, variations of the climatic extremes and the extreme phenomena, augmentation or diminution of the storms on a warmed planet, long term evolution of the climate. Some consequences of a climate change are reviewed: sea level raising, climate change effects on ecosystems. Precision and validity of these predictions are discussed; recommendations for diminishing the uncertainties are proposed

  12. Pollution effects on fisheries — potential management activities

    Science.gov (United States)

    Sindermann, C. J.

    1980-03-01

    Management of ocean pollution must be based on the best available scientific information, with adequate consideration of economic, social, and political realities. Unfortunately, the best available scientific information about pollution effects on fisheries is often fragmentary, and often conjectural; therefore a primary concern of management should be a critical review and assessment of available factual information about effects of pollutants on fish and shellfish stocks. A major problem in any such review and assessment is the separation of pollutant effects from the effects of all the other environmental factors that influence survival and well-being of marine animals. Data from long-term monitoring of resource abundance, and from monitoring of all determinant environmental variables, will be required for analyses that lead to resolution of the problem. Information must also be acquired about fluxes of contaminants through resource-related ecosystems, and about contaminant effects on resource species as demonstrated in field and laboratory experiments. Other possible management activities include: (1) encouragement of continued efforts to document clearly the localized and general effects of pollution on living resources; (2) continued pressure to identify and use reliable biological indicators of environmental degradation (indicators of choice at present are: unusually high levels of genetic and other anomalies in the earliest life history stages; presence of pollution-associated disease signs, particularly fin erosion and ulcers, in fish; and biochemical/physiological changes); and (3) major efforts to reduce inputs of pollutants clearly demonstrated to be harmful to living resources, from point sources as well as ocean dumping. Such pollution management activities, based on continuous efforts in stock assessment, environmental assessment, and experimental studies, can help to insure that rational decisions will be made about uses and abuses of coastal

  13. The potentialities of the wind driven engines with Magnus effect

    International Nuclear Information System (INIS)

    Bychkov, N.M.; Gorelov, V.P.; Gorelov, S.V.; Kachanov, A.N.

    1999-01-01

    Possibilities of wind engine realizing of Magnus effect like of untraditional kind energy source is shown in the article. In this engine instead of traditional propellers the rotatable cylinders are installed. According interaction of the cylinders with wind the Magnus force arises. Magnus force exceeds propellers rise force in 5-10 times and maintain very large turning moment of wind wheel and most effective operation of engine, especially at low wind rates. Advantage of the engine consists in that it switch on under wind rate 1 m/c, when for propeller one requires 4-5 m/c

  14. Biochemical methane potential (BMP) of artichoke waste: the inoculum effect.

    Science.gov (United States)

    Fabbri, Andrea; Serranti, Silvia; Bonifazi, Giuseppe

    2014-03-01

    The aim of this work was to investigate anaerobic digestibility of artichoke waste resulting from industrial transformation. A series of batch anaerobic digestion tests was performed in order to evaluate the biochemical methane potential of the matrix in respect of the process. A comparison of the different performances of the laboratory-scale reactors operating in mesophilic conditions and utilizing three different values of the inoculum/substrate ratio was carried out. The best performance was achieved with an inoculum/substrate ratio of 2. Artichoke-processing byproducts showed a classical organic waste decomposition behaviour: a fast start-up phase, an acclimation stage, and a final stabilization phase. Following this approach, artichoke waste reached chemical oxygen demand removal of about 90% in 40 days. The high methane yield (average 408.62 mL CH4 gvs (-1) voltatile solids), makes artichoke waste a good product to be utilized in anaerobic digestion plants for biogas production.

  15. Fluids in porous media. IV. Quench effect on chemical potential.

    Science.gov (United States)

    Qiao, C Z; Zhao, S L; Liu, H L; Dong, W

    2017-06-21

    It appears to be a common sense to measure the crowdedness of a fluid system by the densities of the species constituting it. In the present work, we show that this ceases to be valid for confined fluids under some conditions. A quite thorough investigation is made for a hard sphere (HS) fluid adsorbed in a hard sphere matrix (a quench-annealed system) and its corresponding equilibrium binary mixture. When fluid particles are larger than matrix particles, the quench-annealed system can appear much more crowded than its corresponding equilibrium binary mixture, i.e., having a much higher fluid chemical potential, even when the density of each species is strictly the same in both systems, respectively. We believe that the insight gained from this study should be useful for the design of functionalized porous materials.

  16. Monsoon effect simulation on typhoon rainfall potential - Typhoon Morakot (2009

    Directory of Open Access Journals (Sweden)

    Yi-Ling Chang

    2017-01-01

    Full Text Available A record breaking extreme precipitation event produced 3000 mm day-1 of accumulated rainfall over southern Taiwan in August 2009. The interactions between Typhoon Morakot and the prevailing southwesterly (SW monsoon are the primary mechanism for this heavy precipitation during 5 - 13 August 2009. This extreme precipitation could be produced by the abundant moisture from the SW monsoon associated with the interaction between typhoon and monsoon wind fields, leading to severe property damage. The accurate mapping of extreme precipitation caused from the interaction between a monsoon and typhoon is critical for early warning in Taiwan. This study simulates the heavy rainfall event is based on the Weather Research and Forecast system model (WRF using the three nested domain configuration. Using data assimilation with a virtual meteorological field using the 3D-Var system, such as wind field to alter the SW monsoon strength in the initial condition, the impacts of intensified convergence and water vapor content on the accumulated rainfall are analyzed to quantize the intensification of typhoon rainfall potential. The results showed a positive correlation between the enhanced precipitation and the intensity of low-level wind speed convergence as well as water vapor content. For the Typhoon Morakot case study the rainfall for could attain approximately 2 × 104 mm at 6 hours interval in the southern Taiwan area when 10 × 10-6 s-1 convergence intensified at 850 hPa level around the southern part of the Taiwan Strait. These results suggest that low-level wind speed, convergence and water vapor content play key roles in the typhoon rainfall potential coupled with the SW monsoon.

  17. Evaluation of Potential Effect of Menthol Solution on Oral Hygiene ...

    African Journals Online (AJOL)

    Purpose: To test the effect of menthol extract on the oral hygiene status of dental students of Faculty of Dentistry, Al- Mustansiriya University, Baghdad, Iraq. Methods: A solution (18 mg %) of menthol was prepared by dissolving menthol crystals in absolute ethanol. Chlorhexidine (CHX, 0.2 %) and deionized water were used ...

  18. The Potential of Directed Instruction to Teach Effectively Technology Usage

    Science.gov (United States)

    Hosseini, Zahra

    2016-01-01

    Currently, teacher educational systems tend to develop their teachers' knowledge to effectively integrate technology in teaching. Consequently, numerous studies have attempted to describe strategies, models and approaches to develop teachers' knowledge for teaching with technology. However, most teachers are still following their traditional…

  19. Leadership Intelligence: Unlocking the Potential for School Leadership Effectiveness

    Science.gov (United States)

    Gage, Timothy; Smith, Clive

    2016-01-01

    Top performing companies have long used intelligence tests in their selection procedures to predict who the best leaders are. However, no longer are the brightest favoured, or guaranteed success. A post-modern world demands a fresh outlook on leadership. How can school leaders judge their effectiveness? How can school leaders lead intelligently?…

  20. Effects of stimulus duration on gustatory evoked potentials

    DEFF Research Database (Denmark)

    Rotvel, Camilla Arndal; Møller, Stine; Kivisaar, Kätlin

    The objective of the present study was to investigate the effect of tastant stimulus duration on the brain response. The brain response was measured by electroencephalography (EEG) which measures neural processes with high temporal resolution and may therefore complement sensory panel assessments...

  1. Capecitabine induced hypertriglyceridaemia: An underreported and potentially severe side effect

    OpenAIRE

    Tabchi S; Joseph K

    2014-01-01

    A 57 year-old-woman, with no previous history of dyslipedemia, developed severe hypertriglyceridemia while being treated with capecitabine for metastatic breast cancer. Capecitabine was not discontinued and serum triglyceride levels were normalized after 4 weeks of treatment with fenofibrate. Capecitabine induced hypertriglyceridemia, as a rare drug-related side effect, seems to be often overlooked by clinicians.

  2. Capecitabine induced hypertriglyceridaemia: An underreported and potentially severe side effect

    Directory of Open Access Journals (Sweden)

    Tabchi S

    2014-05-01

    Full Text Available A 57 year-old-woman, with no previous history of dyslipedemia, developed severe hypertriglyceridemia while being treated with capecitabine for metastatic breast cancer. Capecitabine was not discontinued and serum triglyceride levels were normalized after 4 weeks of treatment with fenofibrate. Capecitabine induced hypertriglyceridemia, as a rare drug-related side effect, seems to be often overlooked by clinicians.

  3. In vitro potential cytogenetic and oxidative stress effects of roxithromycin.

    Science.gov (United States)

    Arslan, Mehmet; Timocin, Taygun; Ila, Hasan B

    2017-10-01

    Macrolide antibiotic roxithromycin was evaluated in terms of its genotoxic, cytotoxic and oxidative stress effects. For this purpose; 25, 50, 100 and 200 μg/mL concentrations of roxithromycin were dissolved in dimethyl sulfoxide and treated to human peripheral blood lymphocytes for two different treatment periods (24 and 48 h). In chromosome aberration (CA) and micronucleus (MN) tests, roxithromycin did not show genotoxic effect. But it induced sister chromatid exchange (SCE) at the highest concentration (200 μg/mL) for the 24-h treatment period and at all concentrations (except 25 μg/mL) for the 48-h treatment period. Looking at cytotoxic effect of roxithromycin, statistically insignificant decreases on mitotic index and proliferation index were observed. Roxithromycin decreased nuclear division index (NDI) at highest two concentrations (100 and 200 μg/mL) for the 24-h treatment period and at all concentrations (expect 25 μg/mL) for the 48-h treatment period. Total oxidant values, total antioxidant values and oxidative stress index did not change with roxithromycin treatment. Eventually, roxithromycin did not have genotoxic and oxidative stress effects in human-cultured lymphocytes.

  4. Effects of prebiotics on the infective potential of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Ebersbach, Tine

    % xylooligosaccharides (XOS), galactooligosaccharides (GOS), inulin, apple pectin or polydextrose for three weeks before oral challenge with L. monocytogenes. XOS and GOS significantly improved resistance of guinea pigs to L. monocytogenes, while inulin and apple pectin decreased the resistance. No significant effect...

  5. Weighing the potential effectiveness of various treatments for sleep bruxism.

    Science.gov (United States)

    Huynh, Nelly; Manzini, Christiane; Rompré, Pierre H; Lavigne, Gilles J

    2007-10-01

    Sleep bruxism may lead to a variety of problems, but its pathophysiology has not been completely elucidated. As such, there is no definitive treatment, but certain preventive measures and/or drugs may be used in acute cases, particularly those involving pain. This article is intended to guide clinician scientists to the treatment most appropriate for future clinical studies. To determine the best current treatment, 2 measures were used to compare the results of 10 clinical studies on sleep bruxism, 3 involving oral devices and 7 involving pharmacologic therapy. The first measure, the number needed to treat (NNT), allows several randomized clinical studies to be compared and a general conclusion to be drawn. The second measure, effect size, allows evaluation of the impact of treatment relative to a placebo using different studies of similar design. Taking into account the NNT, the effect size and the power of each study, it can be concluded that the following treatments reduce sleep bruxism: mandibular advancement device, clonidine and occlusal splint. However, the first 2 of these have been linked to adverse effects. The occlusal splint is therefore the treatment of choice, as it reduces grinding noise and protects the teeth from premature wear with no reported adverse effects. The NNT could not be calculated for an alternative pharmacologic treatment, short-term clonazepam therapy, which had a large effect size and reduced the average bruxism index. However, the risk of dependency limits its use over long periods. Assessment of efficacy and safety of the most promising treatments will require studies with larger sample sizes over longer periods.

  6. The potential effectiveness of nanoparticles as radio sensitizers for radiotherapy

    Directory of Open Access Journals (Sweden)

    Mohammad Babaei

    2014-03-01

    Full Text Available Introduction: Application of nanoparticles as radio sensitizer is a promising field to improve efficiency of radiotherapy.Methods:This study was conducted to review nano radio sensitizers. PubMed, Ovid Medline, Science Direct, Scopus, ISI web of knowledge, and Springer databases were searched from 2000 to May 2013 to identify relevant studies. Search was restricted to English language. Results: We included any study that evaluated nanoparticles, volunteer of radio enhancement at radiotherapy on animals or cell lines. Nanoparticles can increase radio sensitivity of tumor cells. This effect was shown in vivo and in vitro, at kilovltage or megavoltage energies, in 24 reviewed studies. Focus of studies was on gold nanoparticles. Radio sensitizing effects of nanoparticles depend on nanoparticles’ size, type, concentration, intracellular localization, used irradiation energy and tested cell line.Conclusion: Literature suggests potency of nanoparticles for increasing cell radio sensitivity. Reviewed results are promising and warrant future clinical trials.

  7. Potential protective effect of honey against paracetamol-induced hepatotoxicity.

    Science.gov (United States)

    Galal, Reem M; Zaki, Hala F; Seif El-Nasr, Mona M; Agha, Azza M

    2012-11-01

    Paracetamol overdose causes severe hepatotoxicity that leads to liver failure in both humans and experimental animals. The present study investigates the protective effect of honey against paracetamol-induced hepatotoxicity in Wistar albino rats. We have used silymarin as a standard reference hepatoprotective drug. Hepatoprotective activity was assessed by measuring biochemical parameters such as the liver function enzymes, serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST). Equally, comparative effects of honey on oxidative stress biomarkers such as malondialdyhyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx) were also evaluated in the rat liver homogenates.  We estimated the effect of honey on serum levels and hepatic content of interleukin-1beta (IL-1β) because the initial event in paracetamol-induced hepatotoxicity has been shown to be a toxic-metabolic injury that leads to hepatocyte death, activation of the innate immune response and upregulation of inflammatory cytokines. Paracetamol caused marked liver damage as noted by significant increased activities of serum AST and ALT as well as the level of Il-1β. Paracetamol also resulted in a significant decrease in liver GSH content and GPx activity which paralleled an increase in Il-1β and MDA levels. Pretreatment with honey and silymarin prior to the administration of paracetamol significantly prevented the increase in the serum levels of hepatic enzyme markers, and reduced both oxidative stress and inflammatory cytokines. Histopathological evaluation of the livers also revealed that honey reduced the incidence of paracetamol-induced liver lesions. Honey can be used as an effective hepatoprotective agent against paracetamol-induced liver damage.

  8. Effects of Substitutions on the Biodegradation Potential of Benzotriazole Derivatives

    Science.gov (United States)

    Abu-Dalo, M. A.; O'Brien, I.; Hernandez, M. T.

    2018-02-01

    Fourteen benzotriazole derivatives were subjected to microcosm tests to study the influence of substitutions on their biodegradation potential. Methylated, nitrated, carboxylated, and propionated bezotriazoles, a heterocyclic triazole, as well as methylated benzimidazoles, were introduced to activated sludge and soil enrichment cultures as the only carbon source. Some of the enrichment cultures were derived from airport soils that had been previously contaminated with aircraft deicing fluids and subsequently enriched with the commercially significant corrosion inhibitor methylbenzotriazole. The 5-methylbenzotriazole and only the carboxylated derivatives were degraded by soil or activated sludge biomass regardless of acclimation conditions. Radiotracer studies of [U-14C] 5-methylbenzotriazole, and [U-14C] 5-carboxybenzotriazole confirmed that relatively high concentrations (25mg L-1) of these derivatives can be completely mineralized in relatively short time frames by microbial consortia regardless of prior exposure. Observations suggested that the growth yield on these compounds is likely low. Biodegradation patterns suggested that carboxylated benzotriazole derivatives are more readily biodegradable than their more popular methylated counterparts.

  9. Contracting of energy services in Switzerland. Development, effects, market potentials

    International Nuclear Information System (INIS)

    Muggli, C.; Baumgartner, W.; Kohn, L.

    1999-06-01

    The authors of this detailed report first define the contracting of energy services, this new reality of the market place, and analyse its current status in Switzerland. Contracting is mainly to be understood as the delegation of certain energy-related services by a company. The total investment for the operated energy systems considered by the study is about 120 millions USD, with an installed power of 160 MW. This market is highly unhomogeneous and is the answer to various goals. Globally, it brings a more efficient use of energy, including a more frequent involvement of renewable energy sources, along with a lower risk and significant advantages for all contractors. That is the reason for the energy policy authority to recommend contracting. The report goes on with the analysis of the factors leading the chief executives to consider contracting of energy services, or on the contrary to exclude it. The authors estimate the realistic potential market for contracting in Switzerland to 650 millions USD for the period 1999-2004. They conclude by giving recommendations which should result in an acceleration of the contracting's development on the market place

  10. Potentiation of Anticancer Drugs: Effects of Pentoxifylline on Neoplastic Cells

    Directory of Open Access Journals (Sweden)

    Miroslav Barancik

    2011-12-01

    Full Text Available The drug efflux activity of P-glycoprotein (P-gp, a product of the mdr1 gene, ABCB1 member of ABC transporter family represents a mechanism by which tumor cells escape death induced by chemotherapeutics. In this study, we investigated the mechanisms involved in the effects of pentoxifylline (PTX on P-gp-mediated multidrug resistance (MDR in mouse leukemia L1210/VCR cells. Parental sensitive mouse leukemia cells L1210, and multidrug-resistant cells, L1210/VCR, which are characterized by the overexpression of P-gp, were used as experimental models. The cells were exposed to 100 μmol/L PTX in the presence or absence of 1.2 μmol/L vincristine (VCR. Western blot analysis indicated a downregulation of P-gp protein expression when multidrug-resistant L1210/VCR cells were exposed to PTX. The effects of PTX on the sensitization of L1210/VCR cells to VCR correlate with the stimulation of apoptosis detected by Annexin V/propidium iodide apoptosis necrosis kit and proteolytic activation of both caspase-3 and caspase-9 monitored by Western blot analysis. Higher release of matrix metalloproteinases (MMPs, especially MMP-2, which could be attenuated by PTX, was found in L1210/VCR than in L1210 cells by gelatin zymography in electrophoretic gel. Exposure of resistant cells to PTX increased the content of phosphorylated Akt kinase. In contrast, the presence of VCR eliminated the effects of PTX on Akt kinase phosphorylation. Taken together, we conclude that PTX induces the sensitization of multidrug-resistant cells to VCR via downregulation of P-gp, stimulation of apoptosis and reduction of MMPs released from drug-resistant L1210/VCR cells. These facts bring new insights into the mechanisms of PTX action on cancer cells.

  11. Organic food - food quality and potential health effects

    OpenAIRE

    Mie, Axel; Wivstad, Maria

    2015-01-01

    In this report, we try to approach the question “Is organic food healthier than conventional food?” from a scientific perspective. We can conclude that science does not provide a clear answer to this question. A small number of animal studies and epidemiological studies on health effects from the consumption of organic vs. conventional feed/food have been performed. These studies indicate that the production system of the food has some influence on the immune system of the consuming animal or...

  12. Ab initio effective core potentials for molecular calculations. Potentials for the transition metal atoms Sc to Hg

    International Nuclear Information System (INIS)

    Hay, P.J.; Wadt, W.R.

    1985-01-01

    Ab initio effective core potentials (ECP's) have been generated to replace the Coulomb, exchange, and core-orthogonality effects of the chemically inert core electron in the transition metal atoms Sc to Hg. For the second and third transition series relative ECP's have been generated which also incorporate the mass--velocity and Darwin relativistic effects into the potential. The ab initio ECP's should facilitate valence electron calculations on molecules containing transition-metal atoms with accuracies approaching all-electron calculations at a fraction of the computational cost. Analytic fits to the potentials are presented for use in multicenter integral evaluation. Gaussian orbital valence basis sets are developed for the (3d,4s,4p), (4d,5s,5p), and (5d,6s,6p) orbitals of the first, second, and third transition series atoms, respectively. All-electron and valence-electron atomic excitation energies are also compared for the low-lying states of Sc--Hg, and the valence-electron calculations are found to reproduce the all-electron excitation energies (typically within a few tenths of an eV)

  13. Assessing potential legal responses to medical ghostwriting: effectiveness and constitutionality

    Science.gov (United States)

    Chen, Chung-Lin

    2018-01-01

    Abstract Pharmaceutical companies are extensively involved in shaping medical knowledge to market their products to physicians and consumers. Specialized planning is undertaken to produce scientific articles driven by commercial interests. Rather than the listed authors, hidden analysts and publication management firms hired by pharmaceutical companies are often responsible for the content of scientific articles. Such ghostwriting practices raise serious concerns regarding the integrity of knowledge and thus demand urgent attention. This paper analyses the strategies of legal regulation on medical ghostwriting and their comparative advantages and disadvantages. Many of regulatory proposals suffer from a lack of effectiveness, whereas others are subject to constitutional concerns. The analysis in this paper offers insights into framing adequate regulation; it supports the strategy for reforming the structure of information production while calling for cautiousness in shaping its regulatory outline. In addition, this paper contributes to the analysis of First Amendment jurisprudence, suggesting that the judiciary should allow a certain amount of leeway for political branches to develop effective regulation PMID:29707217

  14. Late effects of breast cancer treatment and potentials for rehabilitation

    Energy Technology Data Exchange (ETDEWEB)

    Ewertz, Marianne (Dept. of Oncology, Odense Univ. Hospital, Odense (Denmark)); Bonde Jensen, Anders (Inst. of Clinical Research, Univ. of Southern Denmark (Denmark))

    2011-02-15

    Background. Breast cancer is the most frequent malignant disease among women world wide. Survival has been improving leading to an increasing number of breast cancer survivors, in the US estimated to about 2.6 million. Material and methods. The literature was reviewed with focus on data from the Nordic countries. Results. Local therapies such as breast cancer surgery and radiotherapy may cause persistent pain in the breast area, arm, and shoulder reported by 30-50% of patients after three to five years, lymphedema in 15-25% of patients, and restrictions of arm and shoulder movement in 35%. Physiotherapy is the standard treatment for the latter while no pain intervention trials have been published. Chemotherapy may cause infertility and premature menopause, resulting in vasomotor symptoms, sexual dysfunction, and osteoporosis, which are similar to the side effects of endocrine treatment in postmenopausal women. Awareness of cardiotoxicity is needed since anthracyclines, trastuzumab, and radiotherapy can damage the heart. Breast cancer survivors have an increased risk of a major depression and far from all receive adequate anti-depressive treatment. Other psychological symptoms include fear of recurrence, sleep disturbances, cognitive problems, fatigue, and sexual problems. Discussion. To improve rehabilitation, specific goals have to be formulated into national guidelines and high priority directed towards research into developing and testing new interventions for alleviating symptoms and side effects experienced by breast cancer survivors

  15. Late effects of breast cancer treatment and potentials for rehabilitation

    International Nuclear Information System (INIS)

    Ewertz, Marianne; Bonde Jensen, Anders

    2011-01-01

    Background. Breast cancer is the most frequent malignant disease among women world wide. Survival has been improving leading to an increasing number of breast cancer survivors, in the US estimated to about 2.6 million. Material and methods. The literature was reviewed with focus on data from the Nordic countries. Results. Local therapies such as breast cancer surgery and radiotherapy may cause persistent pain in the breast area, arm, and shoulder reported by 30-50% of patients after three to five years, lymphedema in 15-25% of patients, and restrictions of arm and shoulder movement in 35%. Physiotherapy is the standard treatment for the latter while no pain intervention trials have been published. Chemotherapy may cause infertility and premature menopause, resulting in vasomotor symptoms, sexual dysfunction, and osteoporosis, which are similar to the side effects of endocrine treatment in postmenopausal women. Awareness of cardiotoxicity is needed since anthracyclines, trastuzumab, and radiotherapy can damage the heart. Breast cancer survivors have an increased risk of a major depression and far from all receive adequate anti-depressive treatment. Other psychological symptoms include fear of recurrence, sleep disturbances, cognitive problems, fatigue, and sexual problems. Discussion. To improve rehabilitation, specific goals have to be formulated into national guidelines and high priority directed towards research into developing and testing new interventions for alleviating symptoms and side effects experienced by breast cancer survivors

  16. POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

    Directory of Open Access Journals (Sweden)

    JASMINA JOVIĆ-STOŠIĆ

    2008-03-01

    Full Text Available Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 µm is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases.

  17. Potential indirect effects of aerosol on tropical cyclone development

    Science.gov (United States)

    Krall, Geoffrey

    storm. This study examines the physical mechanisms that could potentially alter a tropical cyclone (TC) in intensity and dynamics upon ingesting elevated levels of CCN.

  18. Potential Effects of Disruptive Political Trends in International Tourism Market

    Directory of Open Access Journals (Sweden)

    Ali Öztüren

    2017-05-01

    Full Text Available The purpose of this paper is to discuss the prospective effects of the latest political incidences on the international tourism market. In this context, the arguments are based on the implications of the USA elections and the Brexit. The methodology of this paper comprises the discussion of the debates related to the recent political experiences. International tourism activities cannot be isolated from the political environment. It is clear that the new political incidences will require novel insights and strategies in conducting international tourism business globally. This paper provides a viewpoint of the today’s political scenarios that will certainly affect the international tourism market. It can be used to comprehend insights that can be used to plan the tourism futures.

  19. Potentially lethal effects of astrophysical high energy explosive events

    International Nuclear Information System (INIS)

    Zarauza, Dario; Martin, Osmel; Rolando Cardenas

    2007-01-01

    In this work we compare the biological extinction risks posed by different types of high energy explosive events, if they occur at distances close enough to inhabited planets. These events are several kinds of supernovae and gamma ray bursts. We mainly consider the ozone depletion, leaving other effects, as photon retransmission and muon showers, for future work. In order to estimate the damage on ozonosphere, we use a simple analytical model for ozone depletion. We also mention some hints to look for the signatures of these events on Earth biogeochemical record, and evaluate the possibility of applying these results to the astrobiologically interesting sample of stars gathered by Porto de Mello, del Peloso and Ghezzi. (Author)

  20. Plant effects on soil denitrification - a review of potential mechanisms

    Science.gov (United States)

    Malique, Francois; Butterbach-Bahl, Klaus; Dannenmann, Michael

    2017-04-01

    Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils. This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates (mainly with regard to the terminal product N2) and the denitrification nitrogen gas product ratios (NO:N2O:N2), Plants may affect denitrification through a myriad of mechanisms such as e.g., competition for nitrate and water, through oxygen consumption, by regulating litter quality and changing soil pH, and via the exudation of labile carbon or secondary plant compounds involved in shaping the rhizospheric microbial community. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years. We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification, e.g. to improve N use efficiency in agricultural ecosystems and to minimize soil nitrous oxide emissions.

  1. Olive Oil and its Potential Effects on Alzheimer's Disease

    Science.gov (United States)

    Antony, Shan; Zhang, G. P.

    Alzheimer's disease is a neuro-degenerative brain disease that is responsible for affecting the lives of hundreds of thousands of people every year. There has been no evidence to suggest a cure for the disease and the only existing treatments have very low rates of success in trial patients. This is largely due to the fact that the brain is one of the most undiscovered parts of the human body. Brain chemistry is highly complex and responds to its environment in random and radical ways. My research includes testing the reactionary outcomes of combining compounds of olive oil with the 20 basic amino acids. Regions around the world with olive oil based diets show a direct correlation to lower rates of Alzheimer's. Testing few compounds of olive oil with chemicals already found in the brain may yield to a better understanding as to why that is. I took the compounds tyrosol, hydroxytyrosol, and oleocanthal, and combined them with the 20 basic amino acids and calculated the total energy of the new molecule. The molecules produced with acceptably low energy values will be the center of further research. These molecules could lead to truly understanding olive oil's effect on the brain, and ultimately, the cure or prevention of Alzheimer's disease.

  2. Potential Positive Effects of Pesticides Application on (Walker (Lepidoptera: Insecta

    Directory of Open Access Journals (Sweden)

    Guo-Qing Yang

    2014-01-01

    Full Text Available In China, the pink stem borer (PSB Sesamia inferens (Walker (Lepidoptera: Noctuidae has become a rice pest in some rice-producing regions. The cause of this shift from secondary to major pest is unknown. The major purpose of this study was to examine the effect of five commonly used pesticides in rice fields on reproduction of PSB and on biochemical substances of rice plants. The results showed that the weight of pupae developed from 1st instar larvae treated with 2 mg/L triazophos and the number of eggs laid by emerged females from the treatment were significantly greater than those of the control, increasing by 26.2% and 47%, respectively. In addition, a nontarget insecticide, pymetrozine 100 mg/L, and a target insecticide, chlorantraniliprole 2 mg/L, stimulated reproduction of PSB. Biochemical measurement showed that foliar sprays of these pesticides resulted in significant reductions of contents of resistant substances, flavonoids and phenolic acids, in rice plants. For example, flavonoids and phenolic acids of rice plants treated with triazophos reduced by 48.5% and 22.4%, respectively, compared to the control. Therefore, we predicted that the application of some pesticides, eg triazophos and chlorantraniliprole, may be the cause of the increase in the population numbers of PSB in rice fields.

  3. The potential chondroprotective effect of propolis in irradiated rats

    International Nuclear Information System (INIS)

    Abd El-Naby, D.H.

    2009-01-01

    Rheumatoid arthritis is a chronic syndrome of unknown etiology and is characterized by non-specific inflammation of the peripheral joints with joint swelling morning stiffness , destruction of articular tissues and joint deformities. It affects nearly 1% of the population worldwide. Ionizing radiation has been shown to exaggerate inflammatory responses, enhance the release of inflammatory mediators, increase oxygen consumption and produce oxygen-free radicals. The exaggerated inflammatory response to irradiation was found to be subdued by propolis, a resinous substance manufactured by honeybees that contains a variety of flavonoids, organic acids, phenols, various enzymes, vitamins and minerals. Propolis has previously been shown to possess antioxidant, anti-inflammatory and immunomodulatory properties. Many of the underlying mechanisms in its multi-faceted properties are interrelated with those that could play a role in arthritis. Since the cartilage breakdown is an essential feature of arthritis, it was therefore of interest to investigate whether or not propolis could have a protective role in this respect. Adjuvant-induced arthritis model in rats was chosen as an established one for chronic inflammation . It is intended to study the effect of whole body exposure to ionizing radiation on cartilage degradation with and without induction of arthritis. The parameters to be studied include glycosaminoglycan and hydroxyproline content in the femoral head cartilage, cartilage oligomeric matrix protein in serum as marker for cartilage destruction as well as pro-inflammatory cytokines (TNF-α, IL-6) and the oxidative stress bio markers (nitric oxide, reduced glutathione and malondialdehyde).

  4. Potential effects of reward and loss avoidance in overweight adolescents.

    Science.gov (United States)

    Reyes, Sussanne; Peirano, Patricio; Luna, Beatriz; Lozoff, Betsy; Algarín, Cecilia

    2015-08-01

    Reward system and inhibitory control are brain functions that exert an influence on eating behavior regulation. We studied the differences in inhibitory control and sensitivity to reward and loss avoidance between overweight/obese and normal-weight adolescents. We assessed 51 overweight/obese and 52 normal-weight 15-y-old Chilean adolescents. The groups were similar regarding sex and intelligence quotient. Using Antisaccade and Incentive tasks, we evaluated inhibitory control and the effect of incentive trials (neutral, loss avoidance, and reward) on generating correct and incorrect responses (latency and error rate). Compared to normal-weight group participants, overweight/obese adolescents showed shorter latency for incorrect antisaccade responses (186.0 (95% CI: 176.8-195.2) vs. 201.3 ms (95% CI: 191.2-211.5), P reward (41.0 (95% CI: 34.5-47.5) vs. 49.8% (95% CI: 43.0-55.1), P reward and loss avoidance trials. These findings could suggest that an imbalance of inhibition and reward systems influence their eating behavior.

  5. Potential effects of invasive Pterois volitans in coral reefs

    Directory of Open Access Journals (Sweden)

    Banamali Maji

    2016-01-01

    Full Text Available The invasion of predatory lionfish (Pterois volitans represents a major threat to the western Atlantic coral reef ecosystems. The proliferation of venomous, fast reproducing and aggressive P. volitans in coral reefs causes severe declines in the abundance and diversity of reef herbivores. There is also widespread cannibalism amongst P. volitans populations. A mathematical model is proposed to study the effects of predation on the biomass of herbivorous reef fishes by considering two life stages and intraguild predation of P. volitans population with harvesting of adult P. volitans. The system undergoes a supercritical Hopf bifurcation when the invasiveness of P. volitans crosses a certain critical value. It is observed that cannibalism of P. volitans induces stability in the system even with high invasiveness of adult P. volitans. The dynamic instability of the system due to higher invasiveness of P. volitans can be controlled by increasing the rate of harvesting of P. volitans. It is also proven that P. volitans goes extinct when the harvest rate is greater than some critical threshold value. These results indicate that the dynamical behaviour of the model is very sensitive to the harvesting of P. volitans, which in turn is useful in the conservation of reef herbivores.

  6. BISPHENOL A AND ITS POTENTIAL TOXIC EFFECTS ON LIVING ORGANISMS

    Directory of Open Access Journals (Sweden)

    Irena Šutiaková

    2012-10-01

    Full Text Available Bisphenol A (BPA, 2, 2,-bis (4-hydroxyphenyl propane, CAS No. 80-05-7, is an industrial chemical that is made by combining acetone and phenol. Food is acknowledged to be a main source of exposure to BPA as a consequence of BPA migration from food containers. Several studies have reported BPA migrations from can surface coatings or plastics into foods and food-simulating liquids at high temperatures, and with repeated use of plastic products. Evaluation of BPA confirmed a no-observable adverse effect level (NOAEL of 5 mg/kg/body weight/day and established a maximum total daily intake (TDI of 0.05 mg/kg body weight. A metabolism of BPA is characterized mainly by phase II conjugation reactions in the gastrointestinal tract and in the liver. The presence of BPA in the environment can cause serious health problems (endocrine disruptions, neurotoxic, genotoxic and other problems. However, there are controversial opinions about BPA. Based on current knowledge of literature the need for further experimental studies in addressing health of human and animal populations living in different ecosystems may be still useful.

  7. Ab initio effective core potentials for molecular calculations. Potentials for K to Au including the outermost core orbitals

    International Nuclear Information System (INIS)

    Hay, P.J.; Wadt, W.R.

    1985-01-01

    Ab initio effective core potentials (ECP's) have been generated to replace the innermost core electron for third-row (K--Au), fourth-row (Rb--Ag), and fifth-row (Cs--Au) atoms. The outermost core orbitals: corresponding to the ns 2 np 6 configuration for the three rows here: are not replaced by the ECP but are treated on an equal footing with the nd, (n+1)s and (n+1)p valence orbitals. These ECP's have been derived for use in molecular calculations where these outer core orbitals need to be treated explicitly rather than to be replaced by an ECP. The ECP's for the forth and fifth rows also incorporate the mass--velocity and Darwin relativistic effects into the potentials. Analytic fits to the potentials are presented for use in multicenter integral evaluation. Gaussian orbital valence basis sets are developed for the (3s, 3p, 3d, 4s, 4p), (4s, 4p, 4d, 5s, 5p), and (5s, 5p, 5d, 6s, 6p) ortibals of the three respective rows

  8. Effect of Zeta Potential on the Properties of Nano-Drug Delivery ...

    African Journals Online (AJOL)

    Zeta potential is a scientific term for electrokinetic potential in colloidal systems which has a major effect on the various properties of nano-drug delivery systems. Presently, colloidal nano-carriers are growing at a remarkable rate owing to their strong potential for overcoming old challenges such as poor drug solubility and ...

  9. Effects of beam, target and substrate potentials in ion beam processing

    International Nuclear Information System (INIS)

    Harper, J.M.E.

    1982-01-01

    Ion beam etching and deposition are normally carried out with beam, target and substrate potentials near ground potential. In this paper, the effects of intentional or unintentional changes in these potentials are described. Examples include beam neutralization, a single extraction grid, substrate bias, and target bias. Each example is described in terms of beam plasma parameters. (Auth.)

  10. On the potential cost effectiveness of scientific audits.

    Science.gov (United States)

    Click, J L

    1989-09-01

    inefficient process for uncovering scientific fraud (5, 6, 9). Data from a survey of university scientists was also presented, indicating ". . . a reluctance to take prompt, corrective action not only when an investigator suspects another of misconduct but also should the investigator discover flaws in his or her own published reports-whether the flaws were the result of honest error or fraud"; (10). The uncritical acceptance by established scientists that the self-correcting process works compounds the problem. The Editor of Science has written that";. . . 99.9999 percent of reports are accurate and truthful. . ."; (8). If indeed only 0.0001% of published reports were inaccurate or untruthful, there would be little justification for scientific audits. However, congressional testimony from the National Institutes of Health (NIH) revealed that";. . . the NIH Director's office has handled an average of 15-20 allegations and reports of misconduct annually in its extramural programs, which supports the work of approximately 50,000 scientists"; (11). As I shall attempt to demonstrate, since NIH alone receives fraud-related complaints concerning the work of at least 0.03% of scientists it supports in other institutions, and since evidence indicates that the incidence of fraud is considerably greater than 0.03% (10, 12), the need to audit data is justifiable on the basis of being cost effective.

  11. [Effects of dauricine on action potentials and slow inward currents of guinea pig ventricular papillary muscles].

    Science.gov (United States)

    Li, S N; Zhang, K Y

    1992-11-01

    Effects of dauricine (Dau) on the action potentials (AP), the slow action potentials (SAP), and the slow inward currents (Isi) of guinea pig ventricular papillary muscles were observed by means of intracellular microelectrode and single sucrose gap voltage clamp technique. In the early stage, Dau shortened action potential duration 100 (APD100) and effective refractory period (ERP) (ERP/APD ERP, and APD20, significantly decreased action potential amplitude (APA), maximum velocity (Vmax), and overshot (OS) (ERP/APD > 1; P SAP induced by isoprenaline (P < 0.01), and remarkably inhibited Isi (P < 0.01). The results suggested that Dau exerted an inhibitory effect on Na+, Ca2+, and K+ channels.

  12. Non-standard perturbative methods for the effective potential in λφ4 QFT

    International Nuclear Information System (INIS)

    Okopinska, A.

    1986-07-01

    The effective potential in scalar QFT is calculated in the non-standard perturbative methods and compared with the conventional loop expansion. In the space time dimensions 0 and 1 the results are compared with the ''exact'' effective potential obtained numerically. In 4 dimensions we show that λφ 4 theory is non-interacting. (author)

  13. Effective potential in the problem of scattering of three charged particles

    International Nuclear Information System (INIS)

    Kvitsinskii, A.A.; Merkur'ev, S.P.

    1988-01-01

    We study the effective interaction potential in the scattering of a charged particle by a bound state of two other charged particles. Scattering by both the ground and excited states of the target is considered. Explicit representations describing the asymptotic structure of effective potentials are proved

  14. Effects of piezoelectric potential on the transport characteristics of metal-ZnO nanowire-metal field effect transistor

    KAUST Repository

    Gao, Zhiyuan; Zhou, Jun; Gu, Yudong; Fei, Peng; Hao, Yue; Bao, Gang; Wang, Zhong Lin

    2009-01-01

    We have investigated the effects of piezoelectric potential in a ZnO nanowire on the transport characteristics of the nanowire based field effect transistor through numerical calculations and experimental observations. Under different straining

  15. Scalar potential from de Sitter brane in 5D and effective cosmological constant

    International Nuclear Information System (INIS)

    Ito, Masato

    2004-01-01

    We derive the scalar potential in zero mode effective action arising from a de Sitter brane embedded in five dimensions with bulk cosmological constant Λ. The scalar potential for a scalar field canonically normalized is given by the sum of exponential potentials. In the case of Λ = 0 and Λ > 0, we point out that the scalar potential has an unstable maximum at the origin and exponentially vanishes for large positive scalar field. In the case of Λ < 0, the scalar potential has an unstable maximum at the origin and a local minimum. It is shown that the positive cosmological constant in dS brane is reduced by negative potential energy of scalar at minimum and that effective cosmological constant depends on a dimensionless quantity. Furthermore, we discuss the fate of our universe including the potential energy of the scalar. (author)

  16. The Potential Neurotoxic Effects of Low-Dose Sarin Exposure in a Guinea Pig Model

    Science.gov (United States)

    2002-01-01

    1 THE POTENTIAL NEUROTOXIC EFFECTS OF LOW-DOSE SARIN EXPOSURE IN A GUINEA PIG MODEL Melinda R. Roberson, PhD, Michelle B. Schmidt...Proving Ground, MD 21010 USA ABSTRACT This study is assessing the effects in guinea pigs of repeated low-dose exposure to the nerve...COVERED - 4. TITLE AND SUBTITLE The Potential Neurotoxic Effects Of Low-Dose Sarin Exposure In A Guinea Pig Model 5a. CONTRACT NUMBER 5b

  17. Structure of the optimized effective Kohn-Sham exchange potential and its gradient approximations

    International Nuclear Information System (INIS)

    Gritsenko, O.; Van Leeuwen, R.; Baerends, E.J.

    1996-01-01

    An analysis of the structure of the optimized effective Kohn-Sham exchange potential v, and its gradient approximations is presented. The potential is decomposed into the Slater potential v s and the response of v s to density variations, v resp . The latter exhibits peaks that reflect the atomic shell structure. Kohn-Sham exchange potentials derived from current gradient approaches for the exchange energy are shown to be quite reasonable for the Slater potential, but they fail to approximate the response part, which leads to poor overall potentials. Improved potentials are constructed by a direct fit of v x with a gradient-dependent Pade approximant form. The potentials obtained possess proper asymptotic and scaling properties and reproduce the shell structure of the exact v x . 44 refs., 7 figs., 4 tabs

  18. Coulomb effect in the tri nucleon system in an optical potential model

    International Nuclear Information System (INIS)

    Adhikari, S.K.; Delfino, A.; Maryland Univ., College Park, MD

    1993-02-01

    A Saxon-Woods type nucleon-deuteron optical potential in suggested and applied numerically to the study of the static Coulomb effect in the low-energy tri nucleon system. In particular, the observed correlations between the static Coulomb energy of 3 He and the triton binding energy, and that between the neutron-deuteron and the proton-deuteron scattering lengths are simulated with this optical potential. In view of this study and a previous one employing two other effective potentials its is unlikely that a a study of the usual static Coulomb effect in the tri nucleon system will reveal new and meaningful physics. (author). 12 refs, 2 figs

  19. Polaron effects on nonlinear optical rectification in asymmetrical Gaussian potential quantum wells with applied electric fields

    International Nuclear Information System (INIS)

    Wu, Jinghe; Guo, Kangxian; Liu, Guanghui

    2014-01-01

    Polaron effects on nonlinear optical rectification in asymmetrical Gaussian potential quantum wells are studied by the effective mass approximation and the perturbation theory. The numerical results show that nonlinear optical rectification coefficients are strongly dependent on the barrier hight V 0 of the Gaussian potential quantum wells, the range L of the confinement potential and the electric field F. Besides, the numerical results show that no matter how V 0 , L and F change, taking into consideration polaron effects, the optical rectification coefficients χ 0 (2) get greatly enhanced.

  20. NUMERICAL STUDY ON COOLING EFFECT POTENTIAL FROM VAPORIZER DEVICE OF LPG VEHICLE

    Directory of Open Access Journals (Sweden)

    MUJI SETIYO

    2017-07-01

    Full Text Available Over fuel consumption and increased exhaust gas due to the A/C system have become a serious problem. On the other hand, the LPG-fueled vehicle provides potential cooling from LPG phase changes in the vaporizer. Therefore, this article presents the potential cooling effect calculation from 1998 cm3 spark ignition (SI engine. A numerical study is used to calculate the potential heat absorption of latent and sensible heat transfer during LPG is expanded in the vaporizer. Various LPG compositions are also simulated through the engine speed range from 1000 to 6000 rpm. The result shows that the 1998 cm3 engine capable of generating the potential cooling effect of about 1.0 kW at 1000 rpm and a maximum of up to 1.8 kW at 5600 rpm. The potential cooling effects from the LPG vaporizer contributes about 26% to the A/C system works on eco-driving condition.

  1. Effective nucleus-nucleus potentials derived from the generator coordinate method

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, H; Canto, L F [Oxford Univ. (UK). Dept. of Theoretical Physics

    1977-11-07

    The equivalence of the generator coordinate method (GCM) and the resonating group method (RGM) and the formal equivalence of the RGM and the orthogonality condition model (OCM) lead to a relation connecting the effective nucleus-nucleus potentials of the OCM with matrix elements of the GCM. This relation may be used to derive effective nucleus-nucleus potentials directly from GCM matrix elements without explicit reference to the potentials of the RGM. In a first application local and l-independent effective potentials are derived from diagonal GCM matrix elements which represent the energy surfaces of a two-centre shell model. Using these potentials the OCM can reproduce the results of a full RGM calculation very well for the elastic scattering of two ..cap alpha..-particles and fairly well for elastic /sup 16/O-/sup 16/O scattering.

  2. Potential impacts on groundwater resources of deep CO2 storage: natural analogues for assessing potential chemical effects

    Science.gov (United States)

    Lions, J.; Gale, I.; May, F.; Nygaard, E.; Ruetters, H.; Beaubien, S.; Sohrabi, M.; Hatzignatiou, D. G.; CO2GeoNet Members involved in the present study Team

    2011-12-01

    Carbon dioxide Capture and Storage (CCS) is considered as one of the promising options for reducing atmospheric emissions of CO2 related to human activities. One of the main concerns associated with the geological storage of CO2 is that the CO2 may leak from the intended storage formation, migrate to the near-surface environment and, eventually, escape from the ground. This is a concern because such leakage may affect aquifers overlying the storage site and containing freshwater that may be used for drinking, industry and agriculture. The IEA Greenhouse Gas R&D Programme (IEAGHG) recently commissioned the CO2GeoNet Association to undertake a review of published and unpublished literature on this topic with the aim of summarizing 'state of the art' knowledge and identifying knowledge gaps and research priorities in this field. Work carried out by various CO2GeoNet members was also used in this study. This study identifies possible areas of conflict by combining available datasets to map the global and regional superposition of deep saline formations (DSF) suitable for CO2 storage and overlying fresh groundwater resources. A scenario classification is developed for the various geological settings where conflict could occur. The study proposes two approaches to address the potential impact mechanisms of CO2 storage projects on the hydrodynamics and chemistry of shallow groundwater. The first classifies and synthesizes changes of water quality observed in natural/industrial analogues and in laboratory experiments. The second reviews hydrodynamic and geochemical models, including coupled multiphase flow and reactive transport. Various models are discussed in terms of their advantages and limitations, with conclusions on possible impacts on groundwater resources. Possible mitigation options to stop or control CO2 leakage are assessed. The effect of CO2 pressure in the host DSF and the potential effects on shallow aquifers are also examined. The study provides a review of

  3. Chemical Potential Dependence of the Dressed-Quark Propagator from an Effective Quark-Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; PING Jia-Lun; SUN Wei-Min; CHANG Chao-Hsi; WANG Fan

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagatorfrom an effective quark-quark interaction model. Within this approach we explore the chemical potential dependenceof the dressed-quark propagator, which provides a means of determining the behavior of the chiral and deconfinementorder parameters. A comparison with the results of previous researches is given.

  4. Investigating transfer gate potential barrier by feed-forward effect measurement

    NARCIS (Netherlands)

    Xu, Y.; Ge, X.; Theuwissen, A.J.P.

    2015-01-01

    In a 4T pixel, the transfer gate (TG) “OFF” surface potential is one of the important parameters, which determines the pinned photodiode (PPD) full well capacity. The feed-forward effect measurement is a powerful tool to characterize the relationship of the PPD injection potential and the

  5. Effective potential for equatorial motion in the Tomimatsu-Sato space-times

    Energy Technology Data Exchange (ETDEWEB)

    Calvani, M [Padua Univ. (Italy). Ist. di Astronomia

    1978-01-28

    We give general rules to draw the effective potential curves for equatorial motion in the T-S space-times either with am. Some general properties of the potentials are pointed out and few examples shown.

  6. The effects of variant descriptors on the potential effectiveness of plain packaging.

    Science.gov (United States)

    Borland, Ron; Savvas, Steven

    2014-01-01

    To examine the effects that variant descriptor labels on cigarette packs have on smokers' perceptions of those packs and the cigarettes contained within. As part of two larger web-based studies (each involved 160 young adult ever-smokers 18-29 years old), respondents were shown a computer image of a plain cigarette pack and sets of related variant descriptors. The sets included terms that varied in terms of descriptors of colours as names, flavour strength, degrees of filter venting, filter types, quality, type of cigarette and numbers. For each set, respondents rated the highest and lowest of two or three of the following four characteristics: quality, strongest or weakest in taste, delivers most or least tar/nicotine, and most or least level of harm. There were significant differences on all four ratings. Quality ratings were the least differentiated. Except for colour descriptors, where 'Gold' rated high in quality but medium in other ratings, ratings of quality, harm, strength and delivery were all positively associated when rated on the same descriptors. Descriptor labels on cigarette packs, can affect smokers' perceptions of the characteristics of the cigarettes contained within. Therefore, they are a potential means by which product differentiation can occur. In particular, having variants differing in perceived strength while not differing in deliveries of harmful ingredients is particularly problematic. Any packaging policy should take into account the possibility that variant descriptors can mislead smokers into making inappropriate product attributions.

  7. Quantum Nuclear Extension of Electron Nuclear Dynamics on Folded Effective-Potential Surfaces

    DEFF Research Database (Denmark)

    Hall, B.; Deumens, E.; Ohrn, Y.

    2014-01-01

    A perennial problem in quantum scattering calculations is accurate theoretical treatment of low energy collisions. We propose a method of extracting a folded, nonadiabatic, effective potential energy surface from electron nuclear dynamics (END) trajectories; we then perform nuclear wave packet...

  8. On the tunneling time of arbitrary continuous potentials and the Hartman effect

    International Nuclear Information System (INIS)

    Yin Cheng; Wu Zhi-Jing; Wang Xian-Ping; Sun Jing-Jing; Cao Zhuang-Qi

    2010-01-01

    This paper obtains a generalized tunneling time of one-dimensional potentials via time reversal invariance. It also proposes a simple explanation for the Hartman effect using the useful concept of the scattered subwaves

  9. Heat Stress in Tunisia: Effects on dairy cows and potential means ...

    African Journals Online (AJOL)

    Heat Stress in Tunisia: Effects on dairy cows and potential means. ... The objectives of this work were to characterize the environmental conditions to which Holstein ... Maintaining cow performance under hot conditions requires the adoption of ...

  10. Agglomeration Determines Effects of Carbonaceous Nanomaterials on Soybean Nodulation, Dinitrogen Fixation Potential, and Growth in Soil

    Science.gov (United States)

    The potential effects of carbonaceous nanomaterials (CNMs) on agricultural plants are of concern. However, little research has been performed using plants cultivated to maturity in soils contaminated with various CNMs at different concentrations. Here, we grew soybean for 39 days...

  11. Finite-temperature effective potential of a system with spontaneously broken symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zemskov, E.P. [Yaroslavl State Technical Univ. (Russian Federation)

    1995-12-01

    A quantum-mechanical system with spontaneously broken symmetry is considered the effective potential is determined, and it is shown that with reduction of temperature the system undergoes a phase transition of the first kind.

  12. Post-Gaussian Effective Potential of Double sine-Gordon Field

    International Nuclear Information System (INIS)

    Cai Weiran; Lou Senyue

    2005-01-01

    In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-ordering prescription. Within the range of convergence, we make a comparison among the classical and the effective potential of the first and second order. The numerical analysis shows that the DsG post-Gaussian EP possesses some fine global properties and makes a substantial and a concordant quantum correction to the features of the classical potential.

  13. Effect of exchange correlation potential on dispersion properties of lower hybrid wave in degenerate plasma

    Science.gov (United States)

    Rimza, Tripti; Sharma, Prerana

    2017-05-01

    The dispersion properties of lower hybrid wave are studied in electron-iondegenerate plasma with exchange effect in non-relativistic regime. It is found that the combined effect of Bohm potential and exchange correlation potential significantly modifies the dispersion properties of lower hybrid wave. The graphical results explicitly show the influence of degeneracy pressure, Bohm force and exchange correlation potential on the frequency of the lower hybrid mode. Present work should be of relevance for the dense astrophysical environments like white dwarfs and for laboratory experiments.

  14. Effects of tacrolimus on action potential configuration and transmembrane ion currents in canine ventricular cells.

    Science.gov (United States)

    Szabó, László; Szentandrássy, Norbert; Kistamás, Kornél; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Horváth, Balázs; Magyar, János; Bányász, Tamás; Pál, Balázs; Nánási, Péter P

    2013-03-01

    Tacrolimus is a commonly used immunosuppressive agent which causes cardiovascular complications, e.g., hypertension and hypertrophic cardiomyopathy. In spite of it, there is little information on the cellular cardiac effects of the immunosuppressive agent tacrolimus in larger mammals. In the present study, therefore, the concentration-dependent effects of tacrolimus on action potential morphology and the underlying ion currents were studied in canine ventricular cardiomyocytes. Standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques were applied in myocytes enzymatically dispersed from canine ventricular myocardium. Tacrolimus (3-30 μM) caused a concentration-dependent reduction of maximum velocity of depolarization and repolarization, action potential amplitude, phase-1 repolarization, action potential duration, and plateau potential, while no significant change in the resting membrane potential was observed. Conventional voltage clamp experiments revealed that tacrolimus concentrations ≥3 μM blocked a variety of ion currents, including I(Ca), I(to), I(K1), I(Kr), and I(Ks). Similar results were obtained under action potential voltage clamp conditions. These effects of tacrolimus developed rapidly and were fully reversible upon washout. The blockade of inward currents with the concomitant shortening of action potential duration in canine myocytes is the opposite of those observed previously with tacrolimus in small rodents. It is concluded that although tacrolimus blocks several ion channels at higher concentrations, there is no risk of direct interaction with cardiac ion channels when applying tacrolimus in therapeutic concentrations.

  15. The effect of interatomic potential in molecular dynamics simulation of low energy ion implantation

    International Nuclear Information System (INIS)

    Chan, H.Y.; Nordlund, K.; Peltola, J.; Gossmann, H.-J.L.; Ma, N.L.; Srinivasan, M.P.; Benistant, F.; Chan, Lap

    2005-01-01

    Being able to accurately predict dopant profiles at sub-keV implant energies is critical for the microelectronic industry. Molecular Dynamics (MD), with its capability to account for multiple interactions as energy lowers, is an increasingly popular simulation method. We report our work on sub-keV implantation using MD and investigate the effect of different interatomic potentials on the range profiles. As an approximation, only pair potentials are considered in this work. Density Functional Theory (DFT) is used to calculate the pair potentials for a wide range of dopants (B, C, N, F, Si, P, Ga, Ge, As, In and Sb) in single crystalline silicon. A commonly used repulsive potential is also included in the study. Importance of the repulsive and attractive regions of the potential has been investigated with different elements and we show that a potential depicting the right attractive forces is especially important for heavy elements at low energies

  16. Gravity-driven groundwater flow and slope failure potential: 1. Elastic effective-stress model

    Science.gov (United States)

    Iverson, Richard M.; Reid, Mark E.

    1992-01-01

    Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, we formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes do not influence effective stresses. We implement the model using two finite element codes. As an illustrative case, we calculate the groundwater flow field, total body force field, and effective stress field in a straight, homogeneous hillslope. The total body force and effective stress fields show that groundwater flow can influence shear stresses as well as effective normal stresses. In most parts of the hillslope, groundwater flow significantly increases the Coulomb failure potential Φ, which we define as the ratio of maximum shear stress to mean effective normal stress. Groundwater flow also shifts the locus of greatest failure potential toward the slope toe. However, the effects of groundwater flow on failure potential are less pronounced than might be anticipated on the basis of a simpler, one-dimensional, limit equilibrium analysis. This is a consequence of continuity, compatibility, and boundary constraints on the two-dimensional flow and stress fields, and it points to important differences between our elastic continuum model and limit equilibrium models commonly used to assess slope stability.

  17. Scaling analysis of the optimized effective potentials for the multiplet states of multivalent 3d ions

    International Nuclear Information System (INIS)

    Hamamoto, N; Satoko, C

    2006-01-01

    We apply the optimized effective potential method (OPM) to the multivalent 3d n (n = 2, ..., 8) ions; M ν+ (ν = 2, ..., 8). The total energy functional is approximated by the single-configuration Hartree-Fock. The exchange potential for the average energy configuration is decomposed into the potentials derived from F 2 (3d, 3d) and F 4 (3d, 3d) Slater integrals. To investigate properties of the density-functional potential, we have checked the scaling properties of several physical quantities such as the density, the 3d orbital and these potentials. We find that the potentials of the Slater integrals do not have the scaling property. Instead, the weighted potential V i (r) of an ion i, which is the potential of the Slater integrals times the 3d-orbital density, satisfies the scaling property q 3d i V i (r) ∼ q 3d j λ 4 V j (λr) where q i 3d is the occupation number of the 3d-orbital R 3d (r) for ion i. Furthermore, the weighted potential can be approximated by the ion-independent functional of the 3d-orbital density c k R 8/3 3d (r)/q 3d where c 2 = 0.366 and c 4 0.223. This suggests that the weighted potential can be expressed as a functional of the 3d-orbital density

  18. Does low-energy physics depend on the potential of a heavy Higgs-particle?

    International Nuclear Information System (INIS)

    Bij, J.J. van der.

    1985-01-01

    The two-loop corrections to vectorboson-propagators and vertices are calculated in the limit of large Higgs-mass for a model with one Higgs-doublet but arbitrary gauge-invariant potential. The corrections are finite even for a non-renormalizable potential. By a suitable choice of the φ 6 term in the potential the corrections due to the Higgs self-coupling are cancelled. (Auth.)

  19. The method of effective potentials in the quantum-statistical theory of plasmas

    International Nuclear Information System (INIS)

    Ebeling, W; Filinov, A; Bonitz, M; Filinov, V; Pohl, T

    2006-01-01

    We provide a survey of the concept and several successful applications of effective potentials. After introducing Kelbg's expression we discuss several useful approximations and additional generalizations including non-diagonal expressions. Finally, we present the recent results concerning non-diagonal contributions and the relation to effective interactions arising from the dynamics of Gaussian wave packets

  20. Identifying potentially cost effective chronic care programs for people with COPD

    NARCIS (Netherlands)

    L.M.G. Steuten (Lotte); K.M.M. Lemmens (Karin); A.P. Nieboer (Anna); H.J.M. Vrijhoef (Hubertus)

    2009-01-01

    textabstractObjective: To review published evidence regarding the cost effectiveness of multi-component COPD programs and to illustrate how potentially cost effective programs can be identified. Methods: Systematic search of Medline and Cochrane databases for evaluations of multicomponent disease

  1. Effect of Glucuronidation on the Potential of Kaempferol to Inhibit Serine/Threonine Protein Kinases

    NARCIS (Netherlands)

    Beekmann, Karsten; Haan, De Laura H.J.; Actis-Goretta, Lucas; Bladeren, Van Peter J.; Rietjens, Ivonne M.C.M.

    2016-01-01

    To study the effect of metabolic conjugation of flavonoids on the potential to inhibit protein kinase activity, the inhibitory effects of the dietary flavonol kaempferol and its major plasma conjugate kaempferol-3-O-glucuronide on protein kinases were studied. To this end, the inhibition of the

  2. Observability of the effects of curl-free magnetic vector potential on ...

    Indian Academy of Sciences (India)

    We discuss here the prediction, based on a formalism by the author, on the observable effects of a curl-free magnetic vector potential on the macroscale as against the microscale of the Aharonov–Bohm effect. A new quantum concept – the 'transition amplitude wave' – postulated in the formalism has already been shown to ...

  3. Effects of climate oscillations on wildland fire potential in the continental United States

    Science.gov (United States)

    Shelby A. Mason; Peter E. Hamlington; Benjamin D. Hamlington; W. Matt Jolly; Chad M. Hoffman

    2017-01-01

    The effects of climate oscillations on spatial and temporal variations in wildland fire potential in the continental U.S. are examined from 1979 to 2015 using cyclostationary empirical orthogonal functions (CSEOFs). The CSEOF analysis isolates effects associated with the modulated annual cycle and the El Niño–Southern Oscillation (ENSO). The results show that, in early...

  4. Differential effects of thioridazine enantiomers on action potential duration in rabbit papillary muscle

    DEFF Research Database (Denmark)

    Jensen, Ask Schou; Pennisi, Cristian Pablo; Sevcencu, Cristian

    2015-01-01

    with (+)-thioridazine. In this study we for the first time investigate the cardiotoxicity of the isolated thioridazine enantiomers and show their effects on ventricular repolarization. The effects of (+)-thioridazine, (-)-thioridazine, and racemate on the rabbit ventricular action potential duration (APD) were...... investigated in a randomized controlled blinded experiment. Action potentials were measured in papillary muscles isolated from 21 female rabbits, and the drug effect on 90% APD in comparison with control (DeltaDelta-APD90) was evaluated. Increasing concentrations of (+)-thioridazine and the racemate caused...

  5. Chiral effective potential in N = {1/2} non-commutative Wess-Zumino model

    International Nuclear Information System (INIS)

    Banin, A.T.; Buchbinder, I.L.; Pletnev, N.G.

    2004-01-01

    We study a structure of holomorphic quantum contributions to the effective action for N = {1/2} noncommutative Wess-Zumino model. Using the symbol operator techniques we present the one-loop chiral effective potential in a form of integral over proper time of the appropriate heat kernel. We prove that this kernel can be exactly found. As a result we obtain the exact integral representation of the one-loop effective potential. Also we study the expansion of the effective potential in a series in powers of the chiral superfield φ and derivative D 2 φ and construct a procedure for systematic calculation of the coefficients in the series. We show that all terms in the series without derivatives can be summed up in an explicit form. (author)

  6. Non-perturbative effective potential: Lower bounds on the Higgs mass and dynamical applications

    International Nuclear Information System (INIS)

    Faivre, H.

    2006-01-01

    The purpose of this work was to assess the benefits of using non-perturbative methods to phenomenological issues in field theory. The exact equations of the Wilson renormalization group (RG) and the effective action have been used, we have computed the energy gap between the first 2 levels in double-well potential. We get a very good agreement with exact solutions inferring from the numerical solving of the Schroedinger equation. RG equations lead to a convex effective potential that is consistent with theory. We have considered the Higgs sector of the standard model. It is commonly acknowledged that the Yukawa coupling between the top quark and the Higgs boson generates the instability of the electroweak vacuum at high energy. We show that this instability does not exist, it is a mere consequence of the extrapolation of the RG equations beyond their validity range. We have also used the effective potential for the description of the time history of the mean value of the quantum field. We have defined the conditions under which the dynamics of the mean value can be described in the local potential approximation by classical equations of motion in which the effective potential replaces the classical potential. (A.C.)

  7. Influence of interface potential on the effective mass in Ge nanostructures

    International Nuclear Information System (INIS)

    Barbagiovanni, E. G.; Cosentino, S.; Terrasi, A.; Mirabella, S.; Lockwood, D. J.; Costa Filho, R. N.

    2015-01-01

    The role of the interface potential on the effective mass of charge carriers is elucidated in this work. We develop a new theoretical formalism using a spatially dependent effective mass that is related to the magnitude of the interface potential. Using this formalism, we studied Ge quantum dots (QDs) formed by plasma enhanced chemical vapour deposition (PECVD) and co-sputtering (sputter). These samples allowed us to isolate important consequences arising from differences in the interface potential. We found that for a higher interface potential, as in the case of PECVD QDs, there is a larger reduction in the effective mass, which increases the confinement energy with respect to the sputter sample. We further understood the action of O interface states by comparing our results with Ge QDs grown by molecular beam epitaxy. It is found that the O states can suppress the influence of the interface potential. From our theoretical formalism, we determine the length scale over which the interface potential influences the effective mass

  8. Comparison of the effect of soft-core potentials and Coulombic potentials on bremsstrahlung during laser matter interaction

    Science.gov (United States)

    Pandit, Rishi R.; Becker, Valerie R.; Barrington, Kasey; Thurston, Jeremy; Ramunno, Lora; Ackad, Edward

    2018-04-01

    An intense, short laser pulse incident on rare-gas clusters can produce nano-plasmas containing energetic electrons. As these electrons undergo scattering, from both phonons and ions, they emit bremsstrahlung radiation. Here, we compare a theory of bremsstrahlung emission appropriate for the interaction of intense lasers with matter using soft-core potentials and Coulombic potentials. A new scaling for the radiation cross-section and the radiated power via bremsstrahlung is derived for a soft-core potential (which depends on the potential depth) and compared with the Coulomb potential. Calculations using the new scaling are performed for electrons in vacuum ultraviolet, infrared and mid-infrared laser pulses. The radiation cross-section and the radiation power via bremsstrahlung are found to increase rapidly with increases in the potential depth of up to around 200 eV and then become mostly saturated for larger depths while remaining constant for the Coulomb potential. In both cases, the radiation cross-section and the radiation power of bremsstrahlung decrease with increases in the laser wavelength. The ratio of the scattering amplitude for the soft-core potential and that for the Coulombic potential decreases exponentially with an increase in momentum transfer. The bremsstrahlung emission by electrons in plasmas may provide a broadband light source for diagnostics.

  9. Effective potential in the strong-coupling lattice QCD with next-to-next-to-learning order effects

    International Nuclear Information System (INIS)

    Nakano, Takashi Z.; Miura, Kohtaroh; Ohnishi, Akira

    2010-01-01

    We derive an analytic expression of the effective potential at finite temperature (T) and chemical potential (μ) in the strong-coupling lattice QCD for color SU(3) including next-to-next-to-leading order (NNLO) effects in the strong coupling expansion. NNLO effective action terms are systematically evaluated in the leading order of the large dimensional (1/d) expansion, and are found to come from some types of connected two-plaquette configurations. We apply the extended Hubbard-Stratonovich transformation and a gluonic-dressed fermion technique to the effective action, and obtain the effective potential as a function of T, μ, and two order parameters: chiral condensate and vector potential field. The next-to-leading order (NLO) and NNLO effects result in modifications of the wave function renormalization factor, quark mass, and chemical potential. We find that T c,μ =0 and μ c,T =0 are similar to the NLO results, whereas the position of the critical point is sensitive to NNLO corrections. (author)

  10. Effect of potential attraction term on surface tension of ionic liquids

    Science.gov (United States)

    Vaziri, N.; Khordad, R.; Rezaei, G.

    2018-03-01

    In this work, we have studied the effect of attraction term of molecular potential on surface tension of ionic liquids (ILs). For this purpose, we have introduced two different potential models to obtain analytical expressions for the surface tension of ILs. The introduced potential models have different attraction terms. The obtained surface tensions in this work have been compared with other theoretical methods and also experimental data. Using the calculated surface tension, the sound velocity is also estimated. We have studied the structural effects on the surface tensions of imidazolium-based ionic liquids. It is found that the cation alkyl chain length and the anion size play important roles to the surface tension of the selected ionic liquids. The calculated surface tensions show a good harmony with experimental data. It is clear that the attraction term of molecular potential has an important role on surface tension and sound velocity of our system.

  11. The Effectiveness of Positive Coping Program on Reduction of Addiction Potential in Students

    Directory of Open Access Journals (Sweden)

    Fatemeh Nematollahi

    2010-02-01

    Full Text Available Objective: This study aimed to study the effectiveness of positive coping program on reduction of addiction potential in dormitory girl students. Method: The research method was semi experimental method namely: pre test-post test with witness group. In selection of sample, first addiction potential scale administered among 160 dormitory girl students, and 20 of them who were scored higher than cutoff score on addiction potential scale selected and divided to two experimental and witness groups. Experimental group received 10 sessions training which each session was 90 minutes. Positive coping program was based on three components of Bob Murray’s theory namely: social relationships, goal setting and spirituality. After finishing of training Post test were administered in both experimental and witness groups. Results: The results showed positive coping training was significantly reduced students’ addiction potential. Conclusion: The training of positive coping can be affect on reduction of girl students’ addiction potential.

  12. Compensation of the skin effect in low-frequency potential drop measurements

    OpenAIRE

    Corcoran, J; Nagy, PB

    2016-01-01

    Potential drop measurements are routinely used in the non-destructive evaluation of component integrity. Potential drop measurements use either direct current (DC) or alternating current (AC), the latter will have superior noise performance due to the ability to perform phase sensitive detection and the reduction of flicker noise. AC measurements are however subject to the skin effect where the current is electromagnetically constricted to the surface of the component. Unfortunately, the skin...

  13. Effect of pH on Pulp Potential and Sulphide Mineral Flotation

    OpenAIRE

    GÖKTEPE, Ferihan

    2014-01-01

    Control of pH is one of the most widely applied methods for the modulation of mineral flotation. In this study the effect of pH on potential in solution and sulphur minerals flotation is discussed with various electrodes. The electrodes were platinum, gold, chalcopyrite, pyrite and galena. In solution, potentials were linearly dependent on pH with a different slope for each electrode. Chalcopyrite, pyrite, sphalerite and galena minerals flotation tests were performed in a microflot...

  14. Gender moderates valence effects on the late positive potential to emotional distracters

    OpenAIRE

    Syrjänen, Elmeri

    2013-01-01

    Attention is captured more strongly by emotional pictures than by neutral pictures. This allocation of attention to emotional pictures is commonly indexed by the late positive potential (LPP), an event-related potential (ERP) that is larger for negative and positive pictures than for neutral pictures. However, findings are mixed in regards to valence effects, that is, whether the LPP is larger for negative pictures than for positive pictures (negativity bias) or vice versa (positivity bias). ...

  15. Reflection effect of localized absorptive potential on non-resonant and resonant tunneling

    International Nuclear Information System (INIS)

    Rubio, A.; Kumar, N.

    1992-06-01

    The reflection due to absorptive potential (-iV i ) for resonant and non-resonant tunneling has been considered. We show that the effect of reflection leads to a non-monotonic dependence of absorption on the strength V i with a maximum absorption of typically 0.5. This has implications for the operation of resonant tunneling devices. General conceptual aspects of absorptive potentials are discussed. (author). 9 refs, 2 figs

  16. Effect of an improved molecular potential on strong-field tunneling ionization of molecules

    International Nuclear Information System (INIS)

    Zhao Songfeng; Jin Cheng; Le, Anh-Thu; Lin, C. D.

    2010-01-01

    We study the effect of one-electron model potentials on the tunneling ionization rates of molecules in strong fields. By including electron correlation using the modified Leeuwen-Baerends (LB α) model, the binding energies of outer shells of molecules are significantly improved. However, we show that the tunneling ionization rates from the LB α do not differ much from the earlier calculations [Phys. Rev. A 81, 033423 (2010)], in which the local correlation potential was neglected.

  17. Investigating CSI: portrayals of DNA testing on a forensic crime show and their potential effects.

    Science.gov (United States)

    Ley, Barbara L; Jankowski, Natalie; Brewer, Paul R

    2012-01-01

    The popularity of forensic crime shows such as CSI has fueled debate about their potential social impact. This study considers CSI's potential effects on public understandings regarding DNA testing in the context of judicial processes, the policy debates surrounding crime laboratory procedures, and the forensic science profession, as well as an effect not discussed in previous accounts: namely, the show's potential impact on public understandings of DNA and genetics more generally. To develop a theoretical foundation for research on the "CSI effect," it draws on cultivation theory, social cognitive theory, and audience reception studies. It then uses content analysis and textual analysis to illuminate how the show depicts DNA testing. The results demonstrate that CSI tends to depict DNA testing as routine, swift, useful, and reliable and that it echoes broader discourses about genetics. At times, however, the show suggests more complex ways of thinking about DNA testing and genetics.

  18. Three-loop Standard Model effective potential at leading order in strong and top Yukawa couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Santa Barbara, KITP

    2014-01-08

    I find the three-loop contribution to the effective potential for the Standard Model Higgs field, in the approximation that the strong and top Yukawa couplings are large compared to all other couplings, using dimensional regularization with modified minimal subtraction. Checks follow from gauge invariance and renormalization group invariance. I also briefly comment on the special problems posed by Goldstone boson contributions to the effective potential, and on the numerical impact of the result on the relations between the Higgs vacuum expectation value, mass, and self-interaction coupling.

  19. Vilkovisky-DeWitt effective potential for Einstein gravity coupled to scalars

    International Nuclear Information System (INIS)

    Cho, H.T.; Department of Physics, Ohio State University, Columbus, Ohio 43210)

    1989-01-01

    The Vilkovisky-DeWitt one-loop effective potential is constructed for Einstein gravity coupled nonminimally to scalars, and is proved explicitly to be independent of gauge choice, for a class of covariant gauges. Explicit forms of the effective potential in three cases are given. The first two cases are used to show that the Vilkovisky-DeWitt formalism is not just a gauge-fixed version of the conventional one in general. The last case concerns the possibility of inducing Einstein gravity dynamically in a Brans-Dicke-type model

  20. Effects of Growth Environment and Ulking Rate on Cyanogenic Potential of Cassava Tuerous Roots

    International Nuclear Information System (INIS)

    Githunguri, C.M

    2002-01-01

    Various abiotic factors affect the pattern of growth and accumulation of cyanogenic glucosides in cassava plants. Five cassava genotypes were planted in a wet and a dry agro-ecological zone and analyzed at 4, 6, 8, 10 and 12 months after planting for tuberous root bulking rate and cyanogenic potential. Cassava plants at Ibadan (the wetter zone) had higher tuberous roots bulking rate and lower cynogenic potential than those planted at Minjibir (the drier zone). Root bulking rate at Ibadan increased from 4 to 6 months after planting, fell to 10 months, and then levelled off thereafter. At Majorana, bulking rate increased from 4 to 6 months, levelling off u pto 8 months after planting, and then falling slightly u pto to 10 months, and rising gradually u pto 12 months after planting. At Minijibir, the 6-8 months after planting period coincided with drought and the highest root bulking rate but increasing cyanogenic potential. Similarly, at Ibadan the 6-8 months after planting period coincided with drought and the highest root bulking rate but increasing cyanogenic potential. Despite the onset of drought, bulking continued up to 8 months after planting, falling u pto 10 months and levelling off thereafter at both agro-ecological zones. However, whereas cyanogenic potential rose rapidly after 8 months to peak at 10 months, and levelling off up to 12 months at Minjibir, cyanogenic potential levelled of after 8 u pto 12 months at Ibadan. Correlation and regression analysis suggested that root bulking rate and cyanogenic potential were negatively associated, meaning that an increase in root bulking rate would lead to corresponding decrease in it's cyanogenic potential which is highly desirable. This study has demonstrated that whereas the plant age and genotypic effects are not important factors in determining tuberous roots bulking rate and cyanogenic potential of cassava, the agro-ecological zone effect is an important factor in determining them

  1. Effects of Acetylcholine and Noradrenalin on Action Potentials of Isolated Rabbit Sinoatrial and Atrial Myocytes

    Science.gov (United States)

    Verkerk, Arie O.; Geuzebroek, Guillaume S. C.; Veldkamp, Marieke W.; Wilders, Ronald

    2012-01-01

    The autonomic nervous system controls heart rate and contractility through sympathetic and parasympathetic inputs to the cardiac tissue, with acetylcholine (ACh) and noradrenalin (NA) as the chemical transmitters. In recent years, it has become clear that specific Regulators of G protein Signaling proteins (RGS proteins) suppress muscarinic sensitivity and parasympathetic tone, identifying RGS proteins as intriguing potential therapeutic targets. In the present study, we have identified the effects of 1 μM ACh and 1 μM NA on the intrinsic action potentials of sinoatrial (SA) nodal and atrial myocytes. Single cells were enzymatically isolated from the SA node or from the left atrium of rabbit hearts. Action potentials were recorded using the amphotericin-perforated patch-clamp technique in the absence and presence of ACh, NA, or a combination of both. In SA nodal myocytes, ACh increased cycle length and decreased diastolic depolarization rate, whereas NA decreased cycle length and increased diastolic depolarization rate. Both ACh and NA increased maximum upstroke velocity. Furthermore, ACh hyperpolarized the maximum diastolic potential. In atrial myocytes stimulated at 2 Hz, both ACh and NA hyperpolarized the maximum diastolic potential, increased the action potential amplitude, and increased the maximum upstroke velocity. Action potential duration at 50 and 90% repolarization was decreased by ACh, but increased by NA. The effects of both ACh and NA on action potential duration showed a dose dependence in the range of 1–1000 nM, while a clear-cut frequency dependence in the range of 1–4 Hz was absent. Intermediate results were obtained in the combined presence of ACh and NA in both SA nodal and atrial myocytes. Our data uncover the extent to which SA nodal and atrial action potentials are intrinsically dependent on ACh, NA, or a combination of both and may thus guide further experiments with RGS proteins. PMID:22754533

  2. Ranitidine Can Potentiate The Prokinetic Effect Of Itopride At Low Doses- An In Vitro Study.

    Science.gov (United States)

    Butt, Aroosa Ishtiaq; Khan, Bushra Tayyaba; Khan, Asma; Khan, Qamar-Uz-Zaman

    2017-01-01

    Gastroparesis and GERD occur concomitantly in 40 percent of the cases. Prokinetic drugs and acid blockers are employed as the main treatment modality. Ranitidine is an acid blocker with additional prokinetic activity and Itopride is a known prokinetic drug. This study was designed to observe the synergistic potentiating prokinetic effect of Ranitidine on itopride on isolated duodenum of rabbits. Ranitidine (10-5-10-3) and itopride (10-6-10-5) were added in increasing concentrations to isolated duodenum of rabbits and contractions were recorded on PowerLab Data acquisition unit AHK/214. Cumulative dose response curves were constructed. The potentiating prokinetic effect of Ranitidine on itopride was seen by using a fixed dose of ranitidine and cumulatively enhancing doses of itopride on iWorx. Ranitidine and itopride produced a dose dependent reversible contraction of the isolated tissue of rabbits with ranitidine showing a max response of 0.124mV and itopride showing a maximum response of 0.131mV. Ranitidine was able to potentiate the prokinetic effect of itopride at low doses but at high dose the effect began to wane off. Ranitidine and itopride produce a statistically significant synergistic potentiating prokinetic effect at low doses in vitro.

  3. Effects of nicotine on visuo-spatial selective attention as indexed by event-related potentials.

    Science.gov (United States)

    Meinke, A; Thiel, C M; Fink, G R

    2006-08-11

    Nicotine has been shown to specifically reduce reaction times to invalidly cued targets in spatial cueing paradigms. In two experiments, we used event-related potentials to test whether the facilitative effect of nicotine upon the detection of invalidly cued targets is due to a modulation of perceptual processing, as indexed by early attention-related event-related potential components. Furthermore, we assessed whether the effect of nicotine on such unattended stimuli depends upon the use of exogenous or endogenous cues. In both experiments, the electroencephalogram was recorded while non-smokers completed discrimination tasks in Posner-type paradigms after chewing a nicotine polacrilex gum (Nicorette 2 mg) in one session and a placebo gum in another session. Nicotine reduced reaction times to invalidly cued targets when cueing was endogenous. In contrast, no differential effect of nicotine on reaction times was observed when exogenous cues were used. Electrophysiologically, we found a similar attentional modulation of the P1 and N1 components under placebo and nicotine but a differential modulation of later event-related potential components at a frontocentral site. The lack of a drug-dependent modulation of P1 and N1 in the presence of a behavioral effect suggests that the effect of nicotine in endogenous visuo-spatial cueing tasks is not due to an alteration of perceptual processes. Rather, the differential modulation of frontocentral event-related potentials suggests that nicotine acts at later stages of target processing.

  4. Reproductive endocrine-disrupting effects of triclosan: Population exposure, present evidence and potential mechanisms

    International Nuclear Information System (INIS)

    Wang, Cai-Feng; Tian, Ying

    2015-01-01

    Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans. - Highlights: • Triclosan is widely detected in human urine, blood and breast milk. • Laboratory studies suggest reproductive endocrine-disrupting effects of triclosan. • Laboratory studies suggest estrogenic properties of triclosan. • There are three potential mechanisms regarding the estrogenic effect of triclosan. • Prospective epidemiological studies on vulnerable populations are needed. - This review summarizes current evidence on human exposure to triclosan, and its reproductive endocrine-disrupting effects and potential mechanisms.

  5. Effects of pioglitazone on cardiac ion currents and action potential morphology in canine ventricular myocytes.

    Science.gov (United States)

    Kistamás, Kornél; Szentandrássy, Norbert; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Bárándi, László; Horváth, Balázs; Szebeni, Andrea; Magyar, János; Bányász, Tamás; Kecskeméti, Valéria; Nánási, Péter P

    2013-06-15

    Despite its widespread therapeutical use there is little information on the cellular cardiac effects of the antidiabetic drug pioglitazone in larger mammals. In the present study, therefore, the concentration-dependent effects of pioglitazone on ion currents and action potential configuration were studied in isolated canine ventricular myocytes using standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques. Pioglitazone decreased the maximum velocity of depolarization and the amplitude of phase-1 repolarization at concentrations ≥3 μM. Action potentials were shortened by pioglitazone at concentrations ≥10 μM, which effect was accompanied with significant reduction of beat-to-beat variability of action potential duration. Several transmembrane ion currents, including the transient outward K(+) current (Ito), the L-type Ca(2+) current (ICa), the rapid and slow components of the delayed rectifier K(+) current (IKr and IKs, respectively), and the inward rectifier K(+) current (IK1) were inhibited by pioglitazone under conventional voltage clamp conditions. Ito was blocked significantly at concentrations ≥3 μM, ICa, IKr, IKs at concentrations ≥10 μM, while IK1 at concentrations ≥30 μM. Suppression of Ito, ICa, IKr, and IK1 has been confirmed also under action potential voltage clamp conditions. ATP-sensitive K(+) current, when activated by lemakalim, was effectively blocked by pioglitazone. Accordingly, action potentials were prolonged by 10 μM pioglitazone when the drug was applied in the presence of lemakalim. All these effects developed rapidly and were readily reversible upon washout. In conclusion, pioglitazone seems to be a harmless agent at usual therapeutic concentrations. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Effect of an educational game on university students' learning about action potentials.

    Science.gov (United States)

    Luchi, Kelly Cristina Gaviao; Montrezor, Luís Henrique; Marcondes, Fernanda K

    2017-06-01

    The aim of this study was to evaluate the effect of an educational game that is used for teaching the mechanisms of the action potentials in cell membranes. The game was composed of pieces representing the intracellular and extracellular environments, ions, ion channels, and the Na + -K + -ATPase pump. During the game activity, the students arranged the pieces to demonstrate how the ions move through the membrane in a resting state and during an action potential, linking the ion movement with a graph of the action potential. To test the effect of the game activity on student understanding, first-year dental students were given the game to play at different times in a series of classes teaching resting membrane potential and action potentials. In all experiments, students who played the game performed better in assessments. According to 98% of the students, the game supported the learning process. The data confirm the students' perception, indicating that the educational game improved their understanding about action potentials. Copyright © 2017 the American Physiological Society.

  7. Choice of single-particle potential and the convergence of the effective interaction

    International Nuclear Information System (INIS)

    Hjorth-Jensen, M.; Osnes, E.; Muether, H.; Schmid, K.W.

    1990-02-01

    The convergence of the expansion for the effective interaction is studied considering as example the shell model for the nuclei 18 O and 18 F. In this work the effective interaction is computed through third order in the Brueckner G matrix, using both a harmonic-oscillator (HO) basis and a Brueckner-Hartree-Fock (BHF) basis. The significant differences in the convergence behavior of the effective interaction in these two cases are reported. The results indicate that the choice of the BHF single-particle potential facilitates the convergence of the effective interaction in low-orders of the expansion, whereas the HO results exhibit a non-convergent behavior. The implications for the HO approach are discussed. All calculations have been performed considering a modern version of the Bonn one-boson-exchange potential for the nucleon-nucleon interaction. 23 refs., 4 figs., 2 tabs

  8. Study on evaluation method for potential effect of natural phenomena on a HLW disposal system

    International Nuclear Information System (INIS)

    Kawamura, Makoto; Makino, Hitoshi; Umeda, Koji; Osawa, Hideaki; Seo, Toshihiro; Ishimaru, Tsuneaki

    2005-01-01

    Evaluation for the potential effect of natural phenomena on a HLW disposal system is an important issue in safety assessment. A scenario construction method for the effects on a HLW disposal system condition and performance has been developed for two purposes: the first being effective elicitation and organization of information from investigators of natural phenomena and performance assessor and the second being, maintenance of traceability of scenario construction processes with suitable records. In this method, a series of works to construct scenarios is divided into pieces to facilitate and to elicit the features of potential effect of natural phenomena on a HLW disposal system and is organized to create reasonable scenarios with consistency, traceability and adequate conservativeness within realistic view. (author)

  9. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water

    Directory of Open Access Journals (Sweden)

    Guoo-Shyng Wang Hsu

    2017-10-01

    Full Text Available Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW. DOW was electrolyzed in a glass electrolyzing cell equipped with platinum–plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be.

  10. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

    Science.gov (United States)

    Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

    2017-10-01

    Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

  11. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Matsukawa, M., E-mail: mmatsuka@mail.doshisha.ac.jp [Wave Electronics Research Center, Laboratory of Ultrasonic Electronics, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan); Mizuno, K. [Underwater Technology Collaborative Research Center, Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Yanagitani, T. [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso cho, Showa-ku, Nagoya 466-8555 (Japan)

    2015-02-16

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  12. Intrinsic potential of cell membranes: opposite effects of lipid transmembrane asymmetry and asymmetric salt ion distribution

    DEFF Research Database (Denmark)

    Gurtovenko, Andrey A; Vattulainen, Ilpo

    2009-01-01

    Using atomic-scale molecular dynamics simulations, we consider the intrinsic cell membrane potential that is found to originate from a subtle interplay between lipid transmembrane asymmetry and the asymmetric distribution of monovalent salt ions on the two sides of the cell membrane. It turns out......Cl saline solution and the PE leaflet is exposed to KCl, the outcome is that the effects of asymmetric lipid and salt ion distributions essentially cancel one another almost completely. Overall, our study highlights the complex nature of the intrinsic potential of cell membranes under physiological...... that both the asymmetric distribution of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) lipids across a membrane and the asymmetric distribution of NaCl and KCl induce nonzero drops in the transmembrane potential. However, these potential drops are opposite in sign. As the PC leaflet faces a Na...

  13. Effect of quantity and composition of waste on the prediction of annual methane potential from landfills.

    Science.gov (United States)

    Cho, Han Sang; Moon, Hee Sun; Kim, Jae Young

    2012-04-01

    A study was conducted to investigate the effect of waste composition change on the methane production in landfills. An empirical equation for the methane potential of the mixed waste is derived based on the methane potential values of individual waste components and the compositional ratio of waste components. A correction factor was introduced in the equation and was determined from the BMP and lysimeter tests. The equation and LandGEM were applied for a full size landfill and the annual methane potential was estimated. Results showed that the changes in quantity of waste affected the annual methane potential from the landfill more than the changes of waste composition. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Effects of grid potentials and geometric dimensions on the multi-electrode probe measurements

    International Nuclear Information System (INIS)

    Elakshar, F.F.; Abdul El-Raoof, W.S.

    1986-01-01

    A hollow anode plasma source is used to produce low temperature plasma which is injected into a magnetic field. The effects of the grid potentials, collector potential and geometric dimensions on multi-electrode probe measurements, in the presence of a magnetic field, are investigated. It is found that the collector potential plays a substantial role in the measurement of temperatures and densities. The finite-size of the geometric dimensions of the probe influences the data and high values of temperature are obtained when a small ratio of the discriminator grid radius to the separation distance is used, providing that the repeller grid potentials is low. Reliable measurements can only be obtained if the multi-electrode probe is used in the presence of a magnetic field strong enough to reduce electron Larmor radii to less than the grid mesh radius. (author)

  15. The effect of empirical potential functions on modeling of amorphous carbon using molecular dynamics method

    International Nuclear Information System (INIS)

    Li, Longqiu; Xu, Ming; Song, Wenping; Ovcharenko, Andrey; Zhang, Guangyu; Jia, Ding

    2013-01-01

    Empirical potentials have a strong effect on the hybridization and structure of amorphous carbon and are of great importance in molecular dynamics (MD) simulations. In this work, amorphous carbon at densities ranging from 2.0 to 3.2 g/cm 3 was modeled by a liquid quenching method using Tersoff, 2nd REBO, and ReaxFF empirical potentials. The hybridization, structure and radial distribution function G(r) of carbon atoms were analyzed as a function of the three potentials mentioned above. The ReaxFF potential is capable to model the change of the structure of amorphous carbon and MD results are in a good agreement with experimental results and density function theory (DFT) at low density of 2.6 g/cm 3 and below. The 2nd REBO potential can be used when amorphous carbon has a very low density of 2.4 g/cm 3 and below. Considering the computational efficiency, the Tersoff potential is recommended to model amorphous carbon at a high density of 2.6 g/cm 3 and above. In addition, the influence of the quenching time on the hybridization content obtained with the three potentials is discussed.

  16. Effects of light and temperature on the growth rate of potentially ...

    African Journals Online (AJOL)

    Thalassiosira allenii is a potentially harmful marine diatom distributed along the Northern Aegean and Southern Black Sea coasts of Turkey. In order to better understand the effect of environmental factors on T. allenii, the effects of 6 different light intensities (6.5, 38.7, 77.5, 116.2, 15 and 193.7 mmol/m2s (PAR)) and 4 ...

  17. Potential Effect of Opium Consumption on Controlling Diabetes and Some Cardiovascular Risk Factors in Diabetic Patients

    OpenAIRE

    Rahimi, Najmeh; Gozashti, Mohamad Hossain; Najafipour, Hamid; Shokoohi, Mostafa; Marefati, Hamid

    2014-01-01

    Background Due to this belief that opium may have beneficial effects on diabetes or cardiovascular risk factors, the present study aimed to assess the potential and possible effects of opium consumption on diabetes control and some cardiovascular risk factors in diabetic patients. Methods This study enrolled 374 diabetic subjects from diabetes care centers in Kerman, Iran, including opium user group (n = 179) and a non-opium user group (n = 195). The data were collected through a questionnair...

  18. [Effect of pulse magnetic field on distribution of neuronal action potential].

    Science.gov (United States)

    Zheng, Yu; Cai, Di; Wang, Jin-Hai; Li, Gang; Lin, Ling

    2014-08-25

    The biological effect on the organism generated by magnetic field is widely studied. The present study was aimed to observe the change of sodium channel under magnetic field in neurons. Cortical neurons of Kunming mice were isolated, subjected to 15 Hz, 1 mT pulse magnetic stimulation, and then the currents of neurons were recorded by whole-cell patch clamp. The results showed that, under magnetic stimulation, the activation process of Na(+) channel was delayed, and the inactivation process was accelerated. Given the classic three-layer model, the polarization diagram of cell membrane potential distribution under pulse magnetic field was simulated, and it was found that the membrane potential induced was associated with the frequency and intensity of magnetic field. Also the effect of magnetic field-induced current on action potential was simulated by Hodgkin-Huxley (H-H) model. The result showed that the generation of action potential was delayed, and frequency and the amplitudes were decreased when working current was between -1.32 μA and 0 μA. When the working current was higher than 0 μA, the generation frequency of action potential was increased, and the change of amplitudes was not obvious, and when the working current was lower than -1.32 μA, the time of rising edge and amplitudes of action potential were decreased drastically, and the action potential was unable to generate. These results suggest that the magnetic field simulation can affect the distribution frequency and amplitude of action potential of neuron via sodium channel mediation.

  19. A simulation for predicting potential cooling effect on LPG-fuelled vehicles

    Science.gov (United States)

    Setiyo, M.; Soeparman, S.; Wahyudi, S.; Hamidi, N.

    2016-03-01

    Liquefied Petroleum Gas vehicles (LPG Vehicles) provide a potential cooling effect about 430 kJ/kg LPG consumption. This cooling effect is obtained from the LPG phase change from liquid to vapor in the vaporizer. In the existing system, energy to evaporate LPG is obtained from the coolant which is circulated around the vaporizer. One advantage is that the LPG (70/30 propane / butane) when expanded from 8 bar to at 1.2 bar, the temperature is less than -25 °C. These conditions provide opportunities to evaporate LPG with ambient air flow, then produce a cooling effect for cooling car's cabin. In this study, some LPG mix was investigated to determine the optimum condition. A simulation was carried out to estimate potential cooling effects of 2000 cc engine from 1000 rpm to 6000 rpm. In this case, the mass flow rate of LPG is a function of fuel consumption. The simulation result shows that the LPG (70/30 propane/butane) provide the greatest cooling effect compared with other mixtures. In conclusion, the 2000 cc engine fueled LPG at 3000 rpm provides potential cooling effect more than 1.3 kW, despite in the low engine speed (1000 rpm) only provides about 0.5 kW.

  20. Effects of inbreeding on potential and realized immune responses in Tenebrio molitor.

    Science.gov (United States)

    Rantala, Markus J; Viitaniemi, Heidi; Roff, Derek A

    2011-06-01

    Although numerous studies on vertebrates suggest that inbreeding reduces their resistance against parasites and pathogens, studies in insects have found contradictory evidence. In this study we tested the effect of 1 generation of brother-sister mating (inbreeding) on potential and realized immune responses and other life-history traits in Tenebrio molitor. We found that inbreeding reduced adult mass, pre-adult survival and increased development time, suggesting that inbreeding reduced the condition of the adults and thus potentially made them more susceptible to physiological stress. However, we found no significant effect of inbreeding on the potential immune response (encapsulation response), but inbreeding reduced the realized immune response (resistance against the entomopathogenic fungi, Beauveria bassiana). There was a significant family effect on encapsulation response, but no family effect on the resistance against the entomopathogenic fungi. Given that this latter trait showed significant inbreeding depression and that the sample size for the family-effect analysis was small it is likely that the lack of a significant family effect is due to reduced statistical power, rather than the lack of a heritable basis to the trait. Our study highlights the importance of using pathogens and parasites in immunoecological studies.

  1. Effect of SRT and temperature on biological conversions and the related scum-forming potential

    NARCIS (Netherlands)

    Halalsheh, M.M.I.; Koppes, J.; Elzen, den J.; Zeeman, G.; Fayyad, M.; Lettinga, G.

    2005-01-01

    Sludge flotation was reported to cause several operational problems in anaerobic systems including UASB reactors treating both strong domestic sewage and some industrial wastewater. This research is to investigate the effect of anaerobic digestion on scum-forming potential (SFP) of sludge and other

  2. Non-coulombic effective power-law potential for the heavy quarkoniums

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N; Jena, S N [Utkal Univ., Bhubaneswar (India). Dept. of Physics

    1980-12-01

    An effective power-law potential of the form V(r) = 6.08 r/sup 0/sup(.)/sup 106/ - 6.41 is found to describe satisfactorily the gross features of the mass spectra and the leptonic width ratios of the cc and bb systems in a flavour-independent manner.

  3. A non-coulombic effective power-law potential for the heavy quarkoniums

    International Nuclear Information System (INIS)

    Barik, N.; Jena, S.N.

    1980-01-01

    An effective power-law potential of the form V(r) = 6.08 r 0 sup(.) 106 - 6.41 is found to describe satisfactorily the gross features of the mass spectra and the leptonic width ratios of the cc and bb systems in a flavour-independent manner. (orig.)

  4. The effects of cortisol administration on approach-avoidance behavior: An event-related potential study

    NARCIS (Netherlands)

    Peer, J.M. van; Roelofs, K.; Rotteveel, M.; Dijk, J.G. van; Spinhoven, P.; Ridderinkhof, K.R.

    2007-01-01

    We investigated the effects of cortisol administration (50 mg) on approach and avoidance tendencies in low and high trait avoidant healthy young men. Event-related brain potentials (ERPs) were measured during a reaction time task, in which participants evaluated the emotional expression of

  5. Retracted: Effects of pro-inflammatory cytokines on mineralization potential of rat dental pulp stem cells

    NARCIS (Netherlands)

    Yang, X.; Walboomers, X.F.; Bian, Z.; Jansen, J.A.; Fan, M.

    2011-01-01

    The following article from the Journal of Tissue Engineering and Regenerative Medicine, 'Effects of Pro-inflammatory Cytokines on Mineralization Potential of Rat Dental Pulp Stem Cells' by Yang X, Walboomers XF, Bian Z, Jansen JA, Fan M, published online on 11 July 2011 in Wiley Online Library

  6. Effect of Zeta Potential on the Properties of Nano-Drug Delivery ...

    African Journals Online (AJOL)

    The zeta potential (ZP) of colloidal systems and nano-medicines, as well as their particle size exert a major effect on the various properties of nano-drug delivery systems. Not only the stability of dosage forms and their release rate are affected but also their circulation in the blood stream and absorption into body membranes ...

  7. Electron structure of molecules with very heavy atoms using effective core potentials

    International Nuclear Information System (INIS)

    Pitzer, K.S.

    1982-01-01

    Topics covered include effective potential, Hamiltonian for valence-electron motion, molecular calculations, spin-spin coupling, L-S coupling, numerical results of molecular calculations, and results of configuration-interaction Slater-orbital calculations in L-S coupling

  8. Effective potential in N=1, d=4 supergravity coupled to the Volkov-Akulov field

    International Nuclear Information System (INIS)

    Jasinschi, R.S.; Smith, A.W.

    1984-01-01

    The only-loop effective potential for N=1, d=4 supergravity theory coupled to the Volkov-Akulov field is calculated. Then it is shown that after an ajustment of some parameters the local supersymmetry is dynamically broken and as a consequence the gravitino acquires mass. (Author) [pt

  9. Effect of extradural morphine on somatosensory evoked potentials to dermatomal stimulation

    DEFF Research Database (Denmark)

    Lund, C; Selmar, P; Hansen, O B

    1987-01-01

    The effect of the extradural (L2-3) administration of morphine 6 mg on early (less than 0.5 s) somatosensory evoked cortical potentials (SEP) to electrical stimulation of the L1- and S1-dermatomes was examined in eight patients. Extradural morphine did not influence SEP amplitude. SEP latency did...

  10. Self-efficacy as a potential moderator of the effects of framed health messages

    NARCIS (Netherlands)

    Werrij, M.Q.; Ruiter, R.A.C.; Riet, van 't J.P.; Vries, de H.

    2011-01-01

    This study focuses on self-efficacy as a potential moderator of the effects of gain- and loss-framed health messages. Undergraduate students (N = 124) received a gain- or loss-framed message about consuming ecological meat. The data revealed that for participants high in self-efficacy, the

  11. The Effect of the Shape of Atomic Potential on the Diffraction Pattern ...

    African Journals Online (AJOL)

    We have simulated the diffraction patterns of both periodic and quasiperiodic monatomic chains using the code Laue (written by Silsbee and Drager) and investigated the effects of the shape of the atomic potential. Three fundamental differences between the diffraction patterns of periodic and quasiperiodic monatomic chain ...

  12. Developing Effective Earthquake Risk Reduction Strategies: The Potential Role of Academic Institutions in Lebanon

    Science.gov (United States)

    Baytiyeh, Hoda

    2015-01-01

    Lebanon faces the risk of powerful earthquakes with potentially devastating effects. However, the Lebanese people in general have not yet recognized this risk, as current educational programs and government officials have failed to inform them about it. This article discusses the essential role that Lebanese institutions of higher education should…

  13. Effect of surgery on sensory threshold and somatosensory evoked potentials after skin stimulation

    DEFF Research Database (Denmark)

    Lund, C; Hansen, O B; Kehlet, H

    1990-01-01

    We have studied the effect of surgical injury on cutaneous sensitivity and somatosensory evoked potentials (SSEP) to dermatomal electrical stimulation in 10 patients undergoing hysterectomy. Forty-eight hours after surgery, sensory threshold increased from 2.2 (SEM 0.3) mA to 4.4 (1.1) mA (P less...

  14. Shadow effect on photovoltaic potentiality analysis using 3D city models

    NARCIS (Netherlands)

    Alam, N.; Coors, V.; Zlatanova, S.; Van Oosterom, P.J.M.

    2012-01-01

    Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases

  15. Exoskeletons for industrial application and their potential effects on physical work load

    NARCIS (Netherlands)

    Looze, M.P. de; Bosch, T.; Krause, F.; Stadler, K.S.; O'Sullivan, L.W.

    2016-01-01

    The aim of this review was to provide an overview of assistive exoskeletons that have specifically been developed for industrial purposes and to assess the potential effect of these exoskeletons on reduction of physical loading on the body. The search resulted in 40 papers describing 26 different

  16. Effect of temperature on development and growth potential of axillary buds in roses

    NARCIS (Netherlands)

    Marcelis-van Acker, C.A.M.

    1995-01-01

    The effect of temperature during axillary bud formation on axillary bud development and subsequent shoot growth was investigated. Growth potential of the axillary buds was studied either in situ, by pruning the parent shoot above the bud, or in isolation, by grafting the bud or by culturing the bud

  17. The finite-temperature Gaussian effective potential from a variational principle

    International Nuclear Information System (INIS)

    Haugerud, H.; Ravndal, F.

    1990-08-01

    Writing the partition function for a scalar quantum field theory as a functional integral, it follows that the finite-temperature Gaussian effective potential is an upper limit to the free energy of the system. Explicit results are given for the anharmonic oscillator at finite temperature. 5 refs., 2 figs

  18. Effect of an Educational Game on University Students' Learning about Action Potentials

    Science.gov (United States)

    Luchi, Kelly Cristina Gaviao; Montrezor, Luís Henrique; Marcondes, Fernanda K.

    2017-01-01

    The aim of this study was to evaluate the effect of an educational game that is used for teaching the mechanisms of the action potentials in cell membranes. The game was composed of pieces representing the intracellular and extracellular environments, ions, ion channels, and the Na+-K+-ATPase pump. During the game activity, the students arranged…

  19. Comment on the accuracy of Rabitz' effective potential approximation for rotational excitation by collisions

    International Nuclear Information System (INIS)

    Green, S.

    1975-01-01

    Cross sections for rotational excitation of HCN by low energy collisions with He have been computed with the effective potential approximation of Rabitz and compared with accurate quantum close-coupling results. Elastic cross sections are found to agree to about 20%; inelastic cross sections agree in general magnitude but not in detailed values for specific quantum transitions

  20. The Rationale for Comparative Effectiveness of Tourist Potential Realization (Case Study of the Volga Region

    Directory of Open Access Journals (Sweden)

    Anna Nikolaevna Polukhina

    2016-11-01

    Full Text Available The article presents the analysis of long-term tourism development programs of the Volga Region. Great attention is given to the sector’s financing measures set out in development programs. Domestic and foreign tourist potential assessment methods are analyzed. Tourist potential dynamics of the Volga Region is studied based on expert opinion. Using econometric approach the authors study the correlation between tourism investments and incomes of the Volga Region for the past six years – from 2009 to 2014. The analysis was carried out using statistics provided by the Russian Tourism Association and the Federal State Statistics Service of the Russian Federation by category of profitability from paid tourist services and from hospitality and catering services. The conducted analysis helped construct the figures showing the differentiation of the Volga regions by tourism investment efficiency and tourist potential realization. It is shown that tourist potential of the territories and its realization are highly differentiated. The sub-regions of the Volga Region are divided into groups according to the effectiveness of potential realization. The effectiveness of implementation of natural recreational and historical and cultural potential is higher in the sub-regions where places of tourist accommodation and entertainment are developed enough, effective mechanisms for programs implementation control are formed and the indicators of expected effectiveness of measures implementation are elaborated. The study has revealed the need for the development of common indicators of expected final results of tourism development programs. The use of a unified system of standardized indicators should become the principle of monitoring the implementation of regional tourism development programs. Data obtained by the research will be useful for the improvement of the existing regional tourism development programs