Synthesis and Characterization of Perovskite Type La1-xSrxAlO3-sigma(0<=X<=0.3) by Co-Precipitation Method

International Nuclear Information System (INIS)

Mahmoud, O.; Abderezak, G.

2015-01-01

This work shows the electrochemical activity of O/sub 2/ evolution reaction in KOH of perovskite type- aluminate oxide (La/sub 1-x/Sr/sub x/AlO/sub 3-sigma/ with x = 0, 0.1, 0.2, 0.3). La/sub 1-x/Sr/sub x/AlO/sub 3-sigma/ (03) was prepared by co-precipitation method. The white precipitates were then washed in distilled water by centrifugation, and calcined at 1000/degree C/ for 6h, the pure phase was characterized by X-ray diffraction (XRD), thermal gravimetric analysis and differential thermal (TG/DSC), Fourier transform infrared spectroscopy (FTIR), specific surface area (BET). The MEB micrographs are shown of the spherical grains and uniform agglomeration of the grains. The oxide powders were used as the films to form a support on Ni/oxides. Oxygen evolution on each oxide catalyst was signed in the cyclic voltammetry with +- 15 V range and the electrochemical impedance in the equivalent of 100 kHz. The results point out the electrode activity and stability of the x = 0.3 composition. (author)

Strings as multi-particle states of quantum sigma-models

International Nuclear Information System (INIS)

Gromov, Nikolay; Kazakov, Vladimir; Sakai, Kazuhiro; Vieira, Pedro

2007-01-01

We study the quantum Bethe ansatz equations in the O(2n) sigma-model for physical particles on a circle, with the interaction given by the Zamolodchikovs'S-matrix, in view of its application to quantization of the string on the S 2n-1 xR t space. For a finite number of particles, the system looks like an inhomogeneous integrable O(2n) spin chain. Similarly to OSp(2m+n|2m) conformal sigma-model considered by Mann and Polchinski, we reproduce in the limit of large density of particles the finite gap Kazakov-Marshakov-Minahan-Zarembo solution for the classical string and its generalization to the S 5 xR t sector of the Green-Schwarz-Metsaev-Tseytlin superstring. We also reproduce some quantum effects: the BMN limit and the quantum homogeneous spin chain similar to the one describing the bosonic sector of the one-loop N=4 super-Yang-Mills theory. We discuss the prospects of generalization of these Bethe equations to the full superstring sigma-model

Locally supersymmetric D=3 non-linear sigma models

International Nuclear Information System (INIS)

Wit, B. de; Tollsten, A.K.; Nicolai, H.

1993-01-01

We study non-linear sigma models with N local supersymmetries in three space-time dimensions. For N=1 and 2 the target space of these models is riemannian or Kaehler, respectively. All N>2 theories are associated with Einstein spaces. For N=3 the target space is quaternionic, while for N=4 it generally decomposes, into two separate quaternionic spaces, associated with inequivalent supermultiplets. For N=5, 6, 8 there is a unique (symmetric) space for any given number of supermultiplets. Beyond that there are only theories based on a single supermultiplet for N=9, 10, 12 and 16, associated with coset spaces with the exceptional isometry groups F 4(-20) , E 6(-14) , E 7(-5) and E 8(+8) , respectively. For N=3 and N ≥ 5 the D=2 theories obtained by dimensional reduction are two-loop finite. (orig.)

Sigma models on supercosets

Energy Technology Data Exchange (ETDEWEB)

Mitev, Vladimir

2010-08-15

The purpose of this thesis is to deepen our understanding of the fundamental properties and defining features of non-linear sigma models on superspaces. We begin by presenting the major concepts that we have used in our investigation, namely Lie superalgebras and supergroups, non-linear sigma models and two dimensional conformal field theory. We then exhibit a method, called cohomological reduction, that makes use of the target space supersymmetry of non-linear sigma models to compute certain correlation functions. We then show how the target space supersymmetry of Ricci flat Lie supergroups simplifies the perturbation theory of suitable deformed Wess-Zumino-Witten models, making it possible to compute boundary conformal weights to all orders. This is then applied to the OSP (2S+2 vertical stroke 2S) Gross-Neveu Model, leading to a dual description in terms of the sigma model on the supersphere S{sup 2S+1} {sup vertical} {sup stroke} {sup 2S}. With this results in mind, we then turn to the similar, yet more intricate, theory of the non-linear sigma model on the complex projective superspaces CP{sup N-1} {sup vertical} {sup stroke} {sup N}. The cohomological reduction allows us to compute several important quantities non-perturbatively with the help of the system of symplectic fermions. Combining this with partial perturbative results for the whole theory, together with numerical computations, we propose a conjecture for the exact evolution of boundary conformal weights for symmetry preserving boundary conditions. (orig.)

Sigma models on supercosets

International Nuclear Information System (INIS)

Mitev, Vladimir

2010-08-01

The purpose of this thesis is to deepen our understanding of the fundamental properties and defining features of non-linear sigma models on superspaces. We begin by presenting the major concepts that we have used in our investigation, namely Lie superalgebras and supergroups, non-linear sigma models and two dimensional conformal field theory. We then exhibit a method, called cohomological reduction, that makes use of the target space supersymmetry of non-linear sigma models to compute certain correlation functions. We then show how the target space supersymmetry of Ricci flat Lie supergroups simplifies the perturbation theory of suitable deformed Wess-Zumino-Witten models, making it possible to compute boundary conformal weights to all orders. This is then applied to the OSP (2S+2 vertical stroke 2S) Gross-Neveu Model, leading to a dual description in terms of the sigma model on the supersphere S 2S+1 vertical stroke 2S . With this results in mind, we then turn to the similar, yet more intricate, theory of the non-linear sigma model on the complex projective superspaces CP N-1 vertical stroke N . The cohomological reduction allows us to compute several important quantities non-perturbatively with the help of the system of symplectic fermions. Combining this with partial perturbative results for the whole theory, together with numerical computations, we propose a conjecture for the exact evolution of boundary conformal weights for symmetry preserving boundary conditions. (orig.)

Quantization of O(N) non-linear sigma models as the stochastic motion on Ssup(N-1)

International Nuclear Information System (INIS)

Aldazabal, G.; Parga, N.

1983-09-01

We obtain the Langevin equations for the stochastic quantization of the O(N) non-linear sigma model by studying the random (Gaussian) motion on the sphere Ssup(N-1). We prove the equivalence of this procedure with a different one where the random forces are elements of the O(N) algebra. A proof that our approach yields in the equilibrium regime the quantum field theory is also given. (author)

Aplicação da metodologia Lean Six Sigma para melhoria de um processo produtivo

OpenAIRE

Augusto Schaffer

2016-01-01

O Lean Six Sigma é a metodologia originada a partir da integração das metodologias Lean e Six Sigma. O Lean Six Sigma procura eliminar as perdas e reduzir os defeitos, agregando os benefícios de cada uma das duas metodologias que a dão origem. O objetivo deste trabalho é aplicar a metodologia Lean Six Sigma para melhoria de um processo produtivo. Neste trabalho é apresentada uma revisão bibliográfica sobre as metodologias Lean e Six Sigma, buscando a compreensão das origens do Lean Six Sigma,...

S-matrix regularities of two-dimensional sigma-models of Stiefel manifolds

International Nuclear Information System (INIS)

Flume-Gorczyca, B.

1980-01-01

The S-matrices of the two-dimensional nonlinear O(n + m)/O(n) and O(n + m)/O(n) x O(m) sigma-models corresponding to Stiefel and Grassmann manifolds, respectively, are compared in leading order in 1/n. It is shown, that after averaging over O(m) labels of the incoming and outgoing particles, the S-matrices of both models become identical. This result explains why commonly expected regularities of the Grassmann models, in particular absence of particle production, are found, modulo an O(m) average, also in Stiefel models. (orig.)

Adoção do Six Sigma pelas 500 Maiores Empresas em PortugalUse of the Six Sigma by the 500 Largent Companies in PortugalAdopción del Six Sigma por las 500 Mayores Empresas de Portugal

Directory of Open Access Journals (Sweden)

CONCEIÇÃO, Ana Cristina Mendes da

2011-09-01

Full Text Available RESUMOO Six Sigma teve sua gênese em empresas industriais de grande porte que o implementaram como uma ferramenta para redução de falhas na área de produção. Seu sucesso inicial estimulou o emprego desta ferramenta em organizações de outros setores em outras áreas além da de produção. O resultado exitoso destas experiências conferiram ao Six Sigma um status de ferramenta de gestão. O objetivo deste estudo é investigar em que medida o Six Sigma está presente nas 500 maiores empresas não-financeiras portuguesas. A coleta de dados deu-se por intermédio de questionário. Os resultados revelam que o êxito na implementação do Six Sigma está condicionado ao envolvimento dos diversos níveis organizacionais. Além disto, os resultados reportam que a implementação do Six Sigma vem acompanhada de ganhos produtividade e, em geral, de uma maior satisfação dos clientes externos. Constatou-se ainda que há pequena expressão nas empresas analisadas embora o interesse pelo mesmo, como ferramenta de gestão, seja apenas suplantado pela ISO 9001 e o Balanced Scorecard.ABSTRACTThe Six Sigma had its genesis in big industrial companies that have implemented it as a tool for reducing defects. The initial success encouraged its application in other areas and we see today successful implementation in other sectors such as services, and within their own organizations in other areas beyond production, setting; this has contributed to Six Sigma being recognized as a new management model. In order to determine the extent to which Six Sigma is present in Portuguese companies, a questionnaire has been designed to target the 500 largest, non-financial companies, operating in Portugal. From the analysis of the results, we can conclude that top management support and the level of involvement of employees in developing and implementing Six Sigma projects are perceived as critical factors in successful implementations. In terms of impact on the

The exact mass-gap of the supersymmetric O(N) sigma model

CERN Document Server

Evans, J M; Evans, Jonathan M; Hollowood, Timothy J

1995-01-01

A formula for the mass-gap of the supersymmetric O(N) sigma model (N>4) in two dimensions is derived: m/\\Lambda_{\\overline{\\rm MS}}=2^{2\\Delta}\\sin(\\pi\\Delta)/(\\pi\\Delta), where \\Delta=1/(N-2) and m is the mass of the fundamental vector particle in the theory. This result is obtained by comparing two expressions for the free-energy density in the presence of a coupling to a conserved charge; one expression is computed from the exact S-matrix of Shankar and Witten via the the thermodynamic Bethe ansatz and the other is computed using conventional perturbation theory. These calculations provide a stringent test of the S-matrix, showing that it correctly reproduces the universal part of the beta-function and resolving the problem of CDD ambiguities.

Heterotic sigma models and non-linear strings

International Nuclear Information System (INIS)

Hull, C.M.

1986-01-01

The two-dimensional supersymmetric non-linear sigma models are examined with respect to the heterotic string. The paper was presented at the workshop on :Supersymmetry and its applications', Cambridge, United Kingdom, 1985. The non-linear sigma model with Wess-Zumino-type term, the coupling of the fermionic superfields to the sigma model, super-conformal invariance, and the supersymmetric string, are all discussed. (U.K.)

Some examples of instantons in sigma models

International Nuclear Information System (INIS)

Kogan, Ya.; Markushevich, D.; Morozov, A.; Ol'shanetskya, M.; Perelomov, A.; Roslij, A.

1988-01-01

Instantons on some manifolds of type K3 are described. Zero modes in two-dimensional sigma models on such manifolds are counted. The necessary facts on K3 manifolds are exposed in monographs. Instanton configurations are described

Precision Islands in the Ising and $O(N)$ Models

CERN Document Server

Kos, Filip; Simmons-Duffin, David; Vichi, Alessandro

2016-01-01

We make precise determinations of the leading scaling dimensions and operator product expansion (OPE) coefficients in the 3d Ising, $O(2)$, and $O(3)$ models from the conformal bootstrap with mixed correlators. We improve on previous studies by scanning over possible relative values of the leading OPE coefficients, which incorporates the physical information that there is only a single operator at a given scaling dimension. The scaling dimensions and OPE coefficients obtained for the 3d Ising model, $(\\Delta_{\\sigma}, \\Delta_{\\epsilon},\\lambda_{\\sigma\\sigma\\epsilon}, \\lambda_{\\epsilon\\epsilon\\epsilon}) = (0.5181489(10), 1.412625(10), 1.0518537(41), 1.532435(19))$, give the most precise determinations of these quantities to date.

Supersymmetric sigma models

International Nuclear Information System (INIS)

Bagger, J.A.

1984-09-01

We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model

Supersymmetric sigma models

Energy Technology Data Exchange (ETDEWEB)

Bagger, J.A.

1984-09-01

We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model.

Classically integrable boundary conditions for symmetric-space sigma models

International Nuclear Information System (INIS)

MacKay, N.J.; Young, C.A.S.

2004-01-01

We investigate boundary conditions for the non-linear sigma model on the compact symmetric space G/H. The Poisson brackets and the classical local conserved charges necessary for integrability are preserved by boundary conditions which correspond to involutions which commute with the involution defining H. Applied to SO(3)/SO(2), the non-linear sigma model on S 2 , these yield the great circles as boundary submanifolds. Applied to GxG/G, they reproduce known results for the principal chiral model

Casimir squared correction to the standard rotator Hamiltonian for the O( n) sigma-model in the delta-regime

Science.gov (United States)

Niedermayer, F.; Weisz, P.

2018-05-01

In a previous paper we found that the isospin susceptibility of the O( n) sigma-model calculated in the standard rotator approximation differs from the next-to-next-to leading order chiral perturbation theory result in terms vanishing like 1 /ℓ, for ℓ = L t /L → ∞ and further showed that this deviation could be described by a correction to the rotator spectrum proportional to the square of the quadratic Casimir invariant. Here we confront this expectation with analytic nonperturbative results on the spectrum in 2 dimensions, by Balog and Hegedüs for n = 3 , 4 and by Gromov, Kazakov and Vieira for n = 4, and find good agreement in both cases. We also consider the case of 3 dimensions.

On a discrete version of the CP 1 sigma model and surfaces immersed in R3

International Nuclear Information System (INIS)

Grundland, A M; Levi, D; Martina, L

2003-01-01

We present a discretization of the CP 1 sigma model. We show that the discrete CP 1 sigma model is described by a nonlinear partial second-order difference equation with rational nonlinearity. To derive discrete surfaces immersed in three-dimensional Euclidean space a 'complex' lattice is introduced. The so-obtained surfaces are characterized in terms of the quadrilateral cross-ratio of four surface points. In this way we prove that all surfaces associated with the discrete CP 1 sigma model are of constant mean curvature. An explicit example of such discrete surfaces is constructed

Two-dimensional sigma models: modelling non-perturbative effects of gauge theories

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.

1984-01-01

The review is devoted to a discussion of non-perturbative effects in gauge theories and two-dimensional sigma models. The main emphasis is put on supersymmetric 0(3) sigma model. The instanton-based method for calculating the exact Gell-Mann-Low function and bifermionic condensate is considered in detail. All aspects of the method in simplifying conditions are discussed. The basic points are: the instanton measure from purely classical analysis; a non-renormalization theorem in self-dual external fields; existence of vacuum condensates and their compatibility with supersymmetry

Reactions of small negative ions with O2(a 1[Delta]g) and O2(X 3[Sigma]g-)

Science.gov (United States)

Midey, Anthony; Dotan, Itzhak; Seeley, J. V.; Viggiano, A. A.

2009-02-01

The rate constants and product ion branching ratios were measured for the reactions of various small negative ions with O2(X 3[Sigma]g-) and O2(a 1[Delta]g) in a selected ion flow tube (SIFT). Only NH2- and CH3O- were found to react with O2(X) and both reactions were slow. CH3O- reacted by hydride transfer, both with and without electron detachment. NH2- formed both OH-, as observed previously, and O2-, the latter via endothermic charge transfer. A temperature study revealed a negative temperature dependence for the former channel and Arrhenius behavior for the endothermic channel, resulting in an overall rate constant with a minimum at 500 K. SF6-, SF4-, SO3- and CO3- were found to react with O2(a 1[Delta]g) with rate constants less than 10-11 cm3 s-1. NH2- reacted rapidly with O2(a 1[Delta]g) by charge transfer. The reactions of HO2- and SO2- proceeded moderately with competition between Penning detachment and charge transfer. SO2- produced a SO4- cluster product in 2% of reactions and HO2- produced O3- in 13% of the reactions. CH3O- proceeded essentially at the collision rate by hydride transfer, again both with and without electron detachment. These results show that charge transfer to O2(a 1[Delta]g) occurs readily if the there are no restrictions on the ion beyond the reaction thermodynamics. The SO2- and HO2- reactions with O2(a) are the only known reactions involving Penning detachment besides the reaction with O2- studied previously [R.S. Berry, Phys. Chem. Chem. Phys., 7 (2005) 289-290].

Nonlinear sigma models with compact hyperbolic target spaces

Energy Technology Data Exchange (ETDEWEB)

Gubser, Steven [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Saleem, Zain H. [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States); National Center for Physics, Quaid-e-Azam University Campus,Islamabad 4400 (Pakistan); Schoenholz, Samuel S. [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States); Stoica, Bogdan [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Stokes, James [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States)

2016-06-23

We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the O(2) model V.L. Berezinskii, Destruction of long-range order in one-dimensional and two-dimensional systems having a continuous symmetry group II. Quantum systems, Sov. Phys. JETP 34 (1972) 610. J.M. Kosterlitz and D.J. Thouless, Ordering, metastability and phase transitions in two-dimensional systems, J. Phys. C 6 (1973) 1181 [http://inspirehep.net/search?p=find+J+%22J.Phys.,C6,1181%22]. . Unlike in the O(2) case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggests that our model is only the simplest example of a broad class of statistical mechanical models whose main features can be understood essentially in geometric terms.

Nonlinear sigma models with compact hyperbolic target spaces

International Nuclear Information System (INIS)

Gubser, Steven; Saleem, Zain H.; Schoenholz, Samuel S.; Stoica, Bogdan; Stokes, James

2016-01-01

We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the O(2) model V.L. Berezinskii, Destruction of long-range order in one-dimensional and two-dimensional systems having a continuous symmetry group II. Quantum systems, Sov. Phys. JETP 34 (1972) 610. J.M. Kosterlitz and D.J. Thouless, Ordering, metastability and phase transitions in two-dimensional systems, J. Phys. C 6 (1973) 1181 [http://inspirehep.net/search?p=find+J+%22J.Phys.,C6,1181%22]. . Unlike in the O(2) case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggests that our model is only the simplest example of a broad class of statistical mechanical models whose main features can be understood essentially in geometric terms.

Six Sigma Driven Enterprise Model Transformation

Directory of Open Access Journals (Sweden)

Raymond Vella

2009-10-01

Full Text Available Enterprise architecture methods provide a structured system to understand enterprise activities. However, existing enterprise modelling methodologies take static views of the enterprise and do not naturally lead to a path of improvement during enterprise model transformation. This paper discusses the need for a methodology to facilitate changes for improvement in an enterprise. The six sigma methodology is proposed as the tool to facilitate progressive and continual Enterprise Model Transformation to allow businesses to adapt to meet increased customer expectation and global competition. An alignment of six sigma with phases of GERAM life cycle is described with inclusion of Critical-To-Satisfaction (CTS requirements. The synergies of combining the two methodologies are presented in an effort to provide a more culturally embedded framework for Enterprise Model Transformation that builds on the success of six sigma.

Some examples of instantons in sigma models

International Nuclear Information System (INIS)

Kogan, Ya.I.; Markushevich, D.G.; Morozov, A.Yu.; Ol'shanetskii, M.A.; Perelomov, A.M.; Roslyi, A.A.

1989-01-01

The paper considers (supersymmetric) sigma models in which the fields are defined on a Riemann surface of genus p and take values on a Kaehlerian manifold. Some mathematical methods for finding instantons and their zero modes in such sigma models are explained. Only holomorphic instantons are considered

Dissipative quantum dynamics and nonlinear sigma-model

International Nuclear Information System (INIS)

Tarasov, V.E.

1992-01-01

Sedov variational principle which is the generalization of the least action principle for the dissipative and irreversible processes and the classical dissipative mechanics in the phase space is considered. Quantum dynamics for the dissipative and irreversible processes is constructed. As an example of the dissipative quantum theory the nonlinear two-dimensional sigma-model is considered. The conformal anomaly of the energy momentum tensor trace for closed bosonic string on the affine-metric manifold is investigated. The two-loop metric beta-function for nonlinear dissipative sigma-model was calculated. The results are compared with the ultraviolet two-loop conterterms for affine-metric sigma model. 71 refs

Large-N limit of the gradient flow in the 2D O(N) nonlinear sigma model

International Nuclear Information System (INIS)

Makino, Hiroki; Sugino, Fumihiko; Suzuki, Hiroshi

2015-01-01

The gradient flow equation in the 2D O(N) nonlinear sigma model with lattice regularization is solved in the leading order of the 1/N expansion. By using this solution, we analytically compute the thermal expectation value of a lattice energy–momentum tensor defined through the gradient flow. The expectation value reproduces thermodynamic quantities obtained by the standard large-N method. This analysis confirms that the above lattice energy–momentum tensor restores the correct normalization automatically in the continuum limit, in a system with a non-perturbative mass gap

On D-branes from gauged linear sigma models

International Nuclear Information System (INIS)

Govindarajan, S.; Jayaraman, T.; Sarkar, T.

2001-01-01

We study both A-type and B-type D-branes in the gauged linear sigma model by considering worldsheets with boundary. The boundary conditions on the matter and vector multiplet fields are first considered in the large-volume phase/non-linear sigma model limit of the corresponding Calabi-Yau manifold, where we find that we need to add a contact term on the boundary. These considerations enable to us to derive the boundary conditions in the full gauged linear sigma model, including the addition of the appropriate boundary contact terms, such that these boundary conditions have the correct non-linear sigma model limit. Most of the analysis is for the case of Calabi-Yau manifolds with one Kaehler modulus (including those corresponding to hypersurfaces in weighted projective space), though we comment on possible generalisations

Comments on Nonlinear Sigma Models Coupled to Supergravity arXiv

CERN Document Server

Ferrara, Sergio

2017-12-10

N=1 , D=4 nonlinear sigma models, parametrized by chiral superfields, usually describe Kählerian geometries, provided that Einstein frame supergravity is used. The sigma model metric is no longer Kähler when local supersymmetry becomes nonlinearly realized through the nilpotency of the supergravity auxiliary fields. In some cases the nonlinear realization eliminates one scalar propagating degree of freedom. This happens when the sigma model conformal-frame metric has co-rank 2. In the geometry of the inflaton, this effect eliminates its scalar superpartner. We show that the sigma model metric remains semidefinite positive in all cases, due the to positivity properties of the conformal-frame sigma model metric.

Inclusive $\\Sigma^{+}$ and $\\Sigma^{0}$ Production in Hadronic Z Decays

CERN Document Server

Acciarri, M.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Ambrosi, G.; Anderhub, H.; Andreev, Valery P.; Angelescu, T.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, L.; Balandras, A.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Barone, L.; Bartalini, P.; Basile, M.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Bhattacharya, S.; Biasini, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brigljevic, V.; Brochu, F.; Buffini, A.; Buijs, A.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Campanelli, Mario; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.M.; Casaus, J.; Castellini, G.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Cesaroni, F.; Chamizo, M.; Chang, Y.H.; Chaturvedi, U.K.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Civinini, C.; Clare, I.; Clare, R.; Coignet, G.; Colijn, A.P.; Colino, N.; Costantini, S.; Cotorobai, F.; Cozzoni, B.; de la Cruz, B.; Csilling, A.; Cucciarelli, S.; Dai, T.S.; van Dalen, J.A.; D'Alessandro, R.; de Asmundis, R.; Deglon, P.; Degre, A.; Deiters, K.; della Volpe, D.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; van Dierendonck, D.; Di Lodovico, F.; Dionisi, C.; Dittmar, M.; Dominguez, A.; Doria, A.; Dova, M.T.; Duchesneau, D.; Dufournaud, D.; Duinker, P.; Duran, I.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Erne, F.C.; Extermann, P.; Fabre, M.; Faccini, R.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisk, I.; Forconi, G.; Fredj, L.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gau, S.S.; Gentile, S.; Gheordanescu, N.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hasan, A.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hidas, P.; Hirschfelder, J.; Hofer, H.; Holzner, G.; Hoorani, H.; Hou, S.R.; Hu, Y.; Iashvili, I.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Khan, R.A.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, D.; Kim, J.K.; Kirkby, Jasper; Kiss, D.; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopp, A.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Krenz, W.; Kruger, A.; Kunin, A.; Ladron Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lassila-Perini, K.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, H.J.; Le Goff, J.M.; Leiste, R.; Leonardi, Emanuele; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Lubelsmeyer, K.; Luci, C.; Luckey, David; Lugnier, L.; Luminari, L.; Lustermann, W.; Ma, W.G.; Maity, M.; Malgeri, L.; Malinin, A.; Mana, C.; Mangeol, D.; Mans, J.; Marchesini, P.; Marian, G.; Martin, J.P.; Marzano, F.; Massaro, G.G.G.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; von der Mey, M.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Molnar, P.; Monteleoni, B.; Moulik, T.; Muanza, G.S.; Muheim, F.; Muijs, A.J.M.; Musy, M.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nisati, A.; Kluge, Hannelies; Organtini, G.; Oulianov, A.; Palomares, C.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Paramatti, R.; Park, H.K.; Park, I.H.; Pascale, G.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Pothier, J.; Produit, N.; Prokofev, D.O.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M.A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Raspereza, A.; Raven, G.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; van Rhee, T.; Riemann, S.; Riles, Keith; Robohm, A.; Rodin, J.; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Rubio, J.A.; Ruschmeier, D.; Rykaczewski, H.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Sanders, M.P.; Sarakinos, M.E.; Schafer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schopper, H.; Schotanus, D.J.; Schwering, G.; Sciacca, C.; Sciarrino, D.; Seganti, A.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Smith, B.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stone, A.; Stone, H.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Suter, H.; Swain, J.D.; Szillasi, Z.; Sztaricskai, T.; Tang, X.W.; Tauscher, L.; Taylor, L.; Tellili, B.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Uchida, Y.; Ulbricht, J.; Valente, E.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobov, A.A.; Vorvolakos, A.; Wadhwa, M.; Wallraff, W.; Wang, M.; Wang, X.L.; Wang, Z.M.; Weber, A.; Weber, M.; Wienemann, P.; Wilkens, H.; Wu, S.X.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Ye, J.B.; Yeh, S.C.; Zalite, A.; Zalite, Yu.; Zhang, Z.P.; Zhu, G.Y.; Zhu, R.Y.; Zichichi, A.; Zilizi, G.; Zoller, M.

2000-01-01

We report on measurements of the inclusive production rate of $\\Sigma^+$ and $\\Sigma^0$ baryons in hadronic Z decays collected with the L3 detector at LEP. The $\\Sigma^+$ baryons are detected through the decay $\\Sigma^+ \\rightarrow {\\rm p} \\pi^0$, while the $\\Sigma^0$ baryons are detected via the decay mode $\\Sigma^0 \\rightarrow \\Lambda \\gamma$. The average numbers of $\\Sigma^+$ and $\\Sigma^0$ per hadronic Z decay are measured to be: \\begin{eqnarray*} \\left + \\left & = & 0.114 \\pm 0.011_{\\mbox{\\it \\small stat}} \\pm 0.009_{\\mbox{\\it \\small syst}} \\\\ \\left + \\left & = & 0.095 \\pm 0.015_{\\mbox{\\it \\small stat}} \\pm 0.013_{\\mbox{\\it \\small syst}} \\ \\mbox{.} \\end{eqnarray*} These rates are found to be higher than the predictions from Monte Carlo hadronization models and analytical parameterizations of strange baryon production.

Twining genera of (0,4) supersymmetric sigma models on K3

International Nuclear Information System (INIS)

Harrison, Sarah; Kachru, Shamit; Paquette, Natalie M.

2014-01-01

Conformal field theories with (0,4) worldsheet supersymmetry and K3 target can be used to compactify the E 8 ×E 8 heterotic string to six dimensions in a supersymmetric manner. The data specifying such a model includes an appropriate configuration of 24 gauge instantons in the E 8 ×E 8 gauge group to satisfy the constraints of anomaly cancellation. In this note, we compute twining genera — elliptic genera with appropriate insertions of discrete symmetry generators in the trace — for (0,4) theories with various instanton embeddings. We do this by constructing linear sigma models which flow to the desired conformal field theories, and using the techniques of localization. We present several examples of such twining genera which are consistent with a moonshine relating these (0,4) models to the finite simple sporadic group M 24

Sigma-2 receptor ligands QSAR model dataset

Directory of Open Access Journals (Sweden)

Antonio Rescifina

2017-08-01

Full Text Available The data have been obtained from the Sigma-2 Receptor Selective Ligands Database (S2RSLDB and refined according to the QSAR requirements. These data provide information about a set of 548 Sigma-2 (σ2 receptor ligands selective over Sigma-1 (σ1 receptor. The development of the QSAR model has been undertaken with the use of CORAL software using SMILES, molecular graphs and hybrid descriptors (SMILES and graph together. Data here reported include the regression for σ2 receptor pKi QSAR models. The QSAR model was also employed to predict the σ2 receptor pKi values of the FDA approved drugs that are herewith included.

Semi-doubled sigma models for five-branes

International Nuclear Information System (INIS)

Kimura, Tetsuji

2016-01-01

We study two-dimensional N=(2,2) gauge theory and its dualized system in terms of complex (linear) superfields and their alternatives. Although this technique itself is not new, we can obtain a new model, the so-called “semi-doubled” GLSM. Similar to doubled sigma model, this involves both the original and dual degrees of freedom simultaneously, whilst the latter only contribute to the system via topological interactions. Applying this to the N=(4,4) GLSM for H-monopoles, i.e., smeared NS5-branes, we obtain its T-dualized systems in quite an easy way. As a bonus, we also obtain the semi-doubled GLSM for an exotic 5_2"3-brane whose background is locally nongeometric. In the low energy limit, we construct the semi-doubled NLSM which also generates the conventional string worldsheet sigma models. In the case of the NLSM for 5_2"3-brane, however, we find that the Dirac monopole equation does not make sense any more because the physical information is absorbed into the divergent part via the smearing procedure. This is nothing but the signal which indicates that the nongeometric feature emerges in the considering model.

High-accuracy critical exponents for O(N) hierarchical 3D sigma models

International Nuclear Information System (INIS)

Godina, J. J.; Li, L.; Meurice, Y.; Oktay, M. B.

2006-01-01

The critical exponent γ and its subleading exponent Δ in the 3D O(N) Dyson's hierarchical model for N up to 20 are calculated with high accuracy. We calculate the critical temperatures for the measure δ(φ-vector.φ-vector-1). We extract the first coefficients of the 1/N expansion from our numerical data. We show that the leading and subleading exponents agree with Polchinski equation and the equivalent Litim equation, in the local potential approximation, with at least 4 significant digits

A construction of observables for AKSZ sigma models

OpenAIRE

Mnev, Pavel

2012-01-01

A construction of gauge-invariant observables is suggested for a class of topological field theories, the AKSZ sigma-models. The observables are associated to extensions of the target Q-manifold of the sigma model to a Q-bundle over it with additional Hamiltonian structure in fibers.

Study of the reactions $\\bar{p}p \\rightarrow \\bar{\\Lambda} \\Lambda , \\bar{\\Lambda} \\Sigma^{0}$ or $\\bar{\\Sigma^{0}} \\Lambda , \\bar{\\Sigma^{+}} \\Sigma^{+}$ at 3.6 GeV/c

CERN Document Server

Atherton, Henry W; Moebes, J P; Quercigh, Emanuele

1974-01-01

The reactions $\\bar{p}p \\rightarrow \\bar{\\Lambda} \\Lambda , \\bar{\\Lambda} \\Sigma^{0}$ or $\\bar{\\Sigma^{0}} \\Lambda , \\bar{\\Sigma^{+}} \\Sigma^{+}$ are studied at an incident momentum of 3.6 GeV/c in a 35.4 event/$\\mu$ b experiment performed in the CERN 2m HBC. Total and differential cross sections are presented. The polarization of the hyperons is measured as a function of $t$ and for the reaction $\\bar{p}p \\rightarrow \\bar{\\Lambda} \\Lambda$ the complete spin correlation matrix is given. (23 refs).

sigma model approach to the heterotic string theory

International Nuclear Information System (INIS)

Sen, A.

1985-09-01

Relation between the equations of motion for the massless fields in the heterotic string theory, and the conformal invariance of the sigma model describing the propagation of the heterotic string in arbitrary background massless fields is discussed. It is emphasized that this sigma model contains complete information about the string theory. Finally, we discuss the extension of the Hull-Witten proof of local gauge and Lorentz invariance of the sigma-model to higher order in α', and the modification of the transformation laws of the antisymmetric tensor field under these symmetries. Presence of anomaly in the naive N = 1/2 supersymmetry transformation is also pointed out in this context. 12 refs

Lectures on nonlinear sigma-models in projective superspace

Energy Technology Data Exchange (ETDEWEB)

Kuzenko, Sergei M, E-mail: kuzenko@cyllene.uwa.edu.a [School of Physics M013, University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia)

2010-11-05

N= 2 supersymmetry in four spacetime dimensions is intimately related to hyperkaehler and quaternionic Kaehler geometries. On one hand, the target spaces for rigid supersymmetric sigma-models are necessarily hyperkaehler manifolds. On the other hand, when coupled to N= 2 supergravity, the sigma-model target spaces must be quaternionic Kaehler. It is known that such manifolds of restricted holonomy are difficult to generate explicitly. Projective superspace is a field-theoretic approach to construct general N= 2 supersymmetric nonlinear sigma-models, and hence to generate new hyperkaehler and quaternionic Kaehler metrics. Intended for a mixed audience consisting of both physicists and mathematicians, these lectures provide a pedagogical introduction to the projective-superspace approach. (topical review)

Lectures on nonlinear sigma-models in projective superspace

International Nuclear Information System (INIS)

Kuzenko, Sergei M

2010-01-01

N= 2 supersymmetry in four spacetime dimensions is intimately related to hyperkaehler and quaternionic Kaehler geometries. On one hand, the target spaces for rigid supersymmetric sigma-models are necessarily hyperkaehler manifolds. On the other hand, when coupled to N= 2 supergravity, the sigma-model target spaces must be quaternionic Kaehler. It is known that such manifolds of restricted holonomy are difficult to generate explicitly. Projective superspace is a field-theoretic approach to construct general N= 2 supersymmetric nonlinear sigma-models, and hence to generate new hyperkaehler and quaternionic Kaehler metrics. Intended for a mixed audience consisting of both physicists and mathematicians, these lectures provide a pedagogical introduction to the projective-superspace approach. (topical review)

Non-perturbative aspects of nonlinear sigma models

Energy Technology Data Exchange (ETDEWEB)

Flore, Raphael

2012-12-07

The aim of this thesis was the study and further development of non-perturbative methods of quantum field theory by means of their application to nonlinear sigma models. While a large part of the physical phenomena of quantum field theory can be successfully predicted by the perturbation theory, some aspects in the region of large coupling strengths are not definitively understood and require suited non-perturbative methods for its analysis. This thesis is concentrated on two approaches, the numerical treatment of field theories on discrete space-time lattices and the functional renormalization group (FRG) as description of the renormalization flux of effective actions. Considerations of the nonlinear O(N) models have shown that for the correct analysis of the critical properties in the framework of the FRG an approach must be chosen, which contained fourth-derivation orders. For this a covariant formalism was developed, which is based on a background-field expansion and the development of a heat kernel. Apart from a destabilizing coupling the results suggest a nontrivial fixed point and by this a non-perturbative renormalizability of these models. The resulting flow diagrams were finally still compared with the results of a numerical analysis of the renormalization flow by means of the Monte-Carlo renormalization group, and hereby qualitative agreement was found. Furthermore an alternative formulation of the FRG in phase-space coordinates was studied and their consistency tested on simple examples. Beyond this an alternative expansion of the effective action in orders of the canonical momenta was applied to the nonlinear O(N) models with the result of a stable non-trivial fixed point, the critical properties of which however show not the expected N-dependence. By means of the FRG finally still the renormalization of topological operators was studied by means of the winding number of the O(3){approx_equal}CP{sup 1} model. By the generalization of the topological

Non-perturbative aspects of nonlinear sigma models

International Nuclear Information System (INIS)

Flore, Raphael

2012-01-01

The aim of this thesis was the study and further development of non-perturbative methods of quantum field theory by means of their application to nonlinear sigma models. While a large part of the physical phenomena of quantum field theory can be successfully predicted by the perturbation theory, some aspects in the region of large coupling strengths are not definitively understood and require suited non-perturbative methods for its analysis. This thesis is concentrated on two approaches, the numerical treatment of field theories on discrete space-time lattices and the functional renormalization group (FRG) as description of the renormalization flux of effective actions. Considerations of the nonlinear O(N) models have shown that for the correct analysis of the critical properties in the framework of the FRG an approach must be chosen, which contained fourth-derivation orders. For this a covariant formalism was developed, which is based on a background-field expansion and the development of a heat kernel. Apart from a destabilizing coupling the results suggest a nontrivial fixed point and by this a non-perturbative renormalizability of these models. The resulting flow diagrams were finally still compared with the results of a numerical analysis of the renormalization flow by means of the Monte-Carlo renormalization group, and hereby qualitative agreement was found. Furthermore an alternative formulation of the FRG in phase-space coordinates was studied and their consistency tested on simple examples. Beyond this an alternative expansion of the effective action in orders of the canonical momenta was applied to the nonlinear O(N) models with the result of a stable non-trivial fixed point, the critical properties of which however show not the expected N-dependence. By means of the FRG finally still the renormalization of topological operators was studied by means of the winding number of the O(3)≅CP 1 model. By the generalization of the topological operator and the

A perturbative approach to mass-generation - the non-linear sigma model

International Nuclear Information System (INIS)

Davis, A.C.; Nahm, W.

1985-01-01

A calculational scheme is presented to include non-perturbative effects into the perturbation expansion. As an example we use the O(N + 1) sigma model. The scheme uses a natural parametrisation such that the lagrangian can be written in a form normal-ordered with respect to the O(N + 1) symmetric vacuum plus vacuum expectation values, the latter calculated by symmetry alone. Including such expectation values automatically leads to the inclusion of a mass-gap in the perturbation series. (orig.)

14-3-3{sigma} controls corneal epithelial cell proliferation and differentiation through the Notch signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Xin, Ying [Stem Cell Institute, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Lu, Qingxian [Tumor Immunobiology Group, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Li, Qiutang, E-mail: q.li@louisville.edu [Stem Cell Institute, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States)

2010-02-19

14-3-3{sigma} (also called stratifin) is specifically expressed in the stratified squamous epithelium and its function was recently shown to be linked to epidermal stratification and differentiation in the skin. In this study, we investigated its role in corneal epithelium cell proliferation and differentiation. We showed that the 14-3-3{sigma} mutation in repeated epilation (Er) mutant mice results in a dominant negative truncated protein. Primary corneal epithelial cells expressing the dominant negative protein failed to undergo high calcium-induced cell cycle arrest and differentiation. We further demonstrated that blocking endogenous 14-3-3{sigma} activity in corneal epithelial cells by overexpressing dominative negative 14-3-3{sigma} led to reduced Notch activity and Notch1/2 transcription. Significantly, expression of the active Notch intracellular domain overcame the block in epithelial cell differentiation in 14-3-3{sigma} mutant-expressing corneal epithelial cells. We conclude that 14-3-3{sigma} is critical for regulating corneal epithelial proliferation and differentiation by regulating Notch signaling activity.

Electrical conduction of glasses in the system Fe2O3-Sb2O3-TeO2; Fe2O3-Sb2O3-TeO2 kei garasu no denki dendo

Energy Technology Data Exchange (ETDEWEB)

Qiu, Honghua; Mori, H; Sakata, H; Hirayama, T [Tokai Univ., Tokyo (Japan). Faculty of Engineering

1995-01-01

In this study, taking into consideration that TeO2 is a component of the glass network and Sb2O3 shows the redox effect in the glasses reducing its possibility of transformation of Sb{sup 3+} to Sb{sup 5+} as well as glass basicity, highly conductive tellurite based glasses have been prepared by the press-quenching method selecting the Fe2O3-Sb2O3-TeO2 system, and the electroconductive mechanism of the glasses has been examined by measuring its D.C. conductivity {sigma}. Part of the obtained information is as follows; the glass formation range of the Fe2O3-Sb2O3-TeO2 system has been 0 {le} Fe2O3 {le} 15mol%, 0 {le} Sb2O3 {le} 18mol% and 78 {le} TeO2 {le} 100mol% and about 15mol% of the additional amount of Fe2O3 has been the limit of glass formation. As the amount of Fe2O3 has increased, C{sub Fe} has also increased and with this, the linear electroconductivity of the glasses has increased from 1.86 {times} 10{sup -7}S{center_dot}cm{sup -1} to 1.62 {times} 10{sup -6}S{center_dot}cm{sup -1} and the glasses have been confirmed as the n-type semiconductor. The factor determining {sigma} of the glasses has been C{sub Fe} which has increased as the amount of Fe2O3 has increased. 34 refs., 8 figs., 2 tabs.

Adoção do Six Sigma pelas 500 Maiores Empresas em Portugal

Use of the Six Sigma by the 500 Largent Companies in Portugal

Adopción del Six Sigma por las 500 Mayores Empresas de Portugal

OpenAIRE

CONCEIÇÃO, Ana Cristina Mendes da; MAJOR, Maria João Martins Ferreira

2011-01-01

RESUMOO Six Sigma teve sua gênese em empresas industriais de grande porte que o implementaram como uma ferramenta para redução de falhas na área de produção. Seu sucesso inicial estimulou o emprego desta ferramenta em organizações de outros setores em outras áreas além da de produção. O resultado exitoso destas experiências conferiram ao Six Sigma um status de ferramenta de gestão. O objetivo deste estudo é investigar em que medida o Six Sigma está presente nas 500 maiores empresas não-financ...

Supersymmetric sigma models and the heterotic string

International Nuclear Information System (INIS)

Hull, C.M.; Witten, E.

1989-01-01

The authors define the (1 + 1)-dimensional supersymmetry algebra of type (p, q) to be that generated by p right-handed Majorana-Weyl supercharges and q left-handed ones. They construct the non-linear sigma models with supersymmetry of type (1, 0) and (2, 0) and discuss their geometry and their relevance to compactifications of the heterotic superstring. The sigma-model anomalies can be canceled by a mechanism closely related to that used by Green and Schwarz to cancel gravitational and Yang-Mills anomalies for the superstring

Relação entre sistemas de medição de desempenho e projetos Seis Sigma: estudo de caso múltiplo The relationship between performance measurement systems and Six Sigma projects: multiple case study

Directory of Open Access Journals (Sweden)

Ricardo Coser Mergulhão

2008-01-01

Full Text Available O objetivo deste artigo é investigar a relação existente entre sistemas de medição de desempenho e desenvolvimento dos projetos seis sigma por meio de estudo de caso múltiplo. O relacionamento mútuo estabelecido a partir do referencial teórico foi observado na pesquisa de campo. Além disto, observou-se que existe um caráter temporal nessa relação. O sistema de medição de desempenho exerce influência primeiro. O relacionamento se dá por meio de fatores que exercem influência positiva e negativa sobre o desenvolvimento dos projetos. Já os projetos seis sigma atuam como alavancas externas na reflexão após o uso do sistema nos projetos levando a modificações no sistema de medição de desempenho.This paper aims to investigate the relationship between performance measurement systems and development of six sigma projects. Five case studies were carried out in Brazilian companies. The empirical findings supported the mutual relationship established after the literature review. Furthermore, a delay was observed in the relationship. The performance measurement system influences first the development of projects. There are factors which exerts both negative and positive influences on projects. In other hand, the six sigma projects play a role of external leverage during the reflection of using performance measurement system which leads to change of such systems.

Doubly graded sigma model with torsion

International Nuclear Information System (INIS)

Kowalski-Glikman, J.

1986-08-01

Using the Hull-Witten construction we show how to introduce torsion to the doubly graded sigma model. This construction enables us to find a link between this model and the ten-dimensional supergravity theory in superspace. (Auth.)

Introduction to sigma model anomalies

International Nuclear Information System (INIS)

Nelson, P.

1985-01-01

This paper presents results dealing with the specific case in which a sigma model with fermions arises as a result of dynamical symmetry breakdown from some group G to a subgroup H. H may contain chiral symmetries protecting some fermions in a representation ρ H of H. In this case it may be impossible to quantize the remaining fermions in a way which reproduces the anomalous Ward identities of any underlying strongly-interacting gauge theory. The author concludes that this pattern of symmetry breakdown will not be realized in any such theory. The criterion in this case is local in character, since roughly speaking once the sigma model in question behaves for field configurations close to the vacuum base point in the internal mainfold is known, symmetry can be used to find how it behaves everywhere else

A new class of superconformal sigma models with the Wess-Zumino action

International Nuclear Information System (INIS)

Ivanov, E.A.; Krivonos, S.O.

1987-01-01

Nonlinear sigma models are constructed for infinite-dimensional N-extended D=2 superconformal symmetries (of the type (N,N)). These are classically integrable and naturally incorporate conformally invariant bosonic Wess-Zumino sigma model defined on the supersymmetry automorphism group SO - (N)xSO + (N). A finite set of basic Nambu-Goldstone superfields is singled out by imposing infinitely many covariant constraints on the relevant Cartan 1-forms. The resulting superfield equations of motion and off-shell irreducibility conditions have a universal for any N. The N3 and N=4 models are examined in detail

Squashed Toric Sigma Models and Mock Modular Forms

Science.gov (United States)

Gupta, Rajesh Kumar; Murthy, Sameer

2018-05-01

We study a class of two-dimensional N}=(2,2)} sigma models called squashed toric sigma models, using their Gauged Linear Sigma Models (GLSM) description. These models are obtained by gauging the global {U(1)} symmetries of toric GLSMs and introducing a set of corresponding compensator superfields. The geometry of the resulting vacuum manifold is a deformation of the corresponding toric manifold in which the torus fibration maintains a constant size in the interior of the manifold, thus producing a neck-like region. We compute the elliptic genus of these models, using localization, in the case when the unsquashed vacuum manifolds obey the Calabi-Yau condition. The elliptic genera have a non-holomorphic dependence on the modular parameter {τ} coming from the continuum produced by the neck. In the simplest case corresponding to squashed {C / Z_{2 the elliptic genus is a mixed mock Jacobi form which coincides with the elliptic genus of the {N=(2,2)} {SL(2,R) / U(1)} cigar coset.

Quasicomplex N=2, d=1 Supersymmetric Sigma Models

Directory of Open Access Journals (Sweden)

Evgeny A. Ivanov

2013-11-01

Full Text Available We derive and discuss a new type of N=2 supersymmetric quantum mechanical sigma models which appear when the superfield action of the (1,2,1 multiplets is modified by adding an imaginary antisymmetric tensor to the target space metric, thus completing the latter to a non-symmetric Hermitian metric. These models are not equivalent to the standard de Rham sigma models, but are related to them through a certain special similarity transformation of the supercharges. On the other hand, they can be obtained by a Hamiltonian reduction from the complex supersymmetric N=2 sigma models built on the multiplets (2,2,0 and describing the Dolbeault complex on the manifolds with proper isometries. We study in detail the extremal two-dimensional case, when the target space metric is defined solely by the antisymmetric tensor, and show that the corresponding quantum systems reveal a hidden N=4 supersymmetry.

The Effect of the Spin-Forbidden Co((sup 1) Sigma plus) plus O((sup 3) P) Yields CO2 (1 Sigma (sub G) plus) Recombination Reaction on Afterbody Heating of Mars Entry Vehicles

Science.gov (United States)

Xu, Lu T.; Jaffe, Richard L.; Schwenke, David W.; Panesi, Marco

2017-01-01

Vibrationally excited CO2, formed by two-body recombination from CO((sup 1) sigma plus) and O((sup 3) P) in the wake behind spacecraft entering the Martian atmosphere reaction, is potentially responsible for the higher than anticipated radiative heating of the backshell, compared to pre-flight predictions. This process involves a spin-forbidden transition of the transient triplet CO2 molecule to the longer-lived singlet. To accurately predict the singlet-triplet transition probability and estimate the thermal rate coefficient of the recombination reaction, ab initio methods were used to compute the first singlet and three lowest triplet CO2 potential energy surfaces and the spin-orbit coupling matrix elements between these states. Analytical fits to these four potential energy surfaces were generated for surface hopping trajectory calculations, using Tully's fewest switches surface hopping algorithm. Preliminary results for the trajectory calculations are presented. The calculated probability of a CO((sup 1) sigma plus) and O((sup 3) P) collision leading to singlet CO2 formation is on the order of 10 (sup -4). The predicted flowfield conditions for various Mars entry scenarios predict temperatures in the range of 1000 degrees Kelvin - 4000 degrees Kelvin and pressures in the range of 300-2500 pascals at the shoulder and in the wake, which is consistent with a heavy-particle collision frequency of 10 (sup 6) to 10 (sup 7) per second. Owing to this low collision frequency, it is likely that CO((sup 1) sigma plus) molecules formed by this mechanism will mostly be frozen in a highly nonequilibrium rovibrational energy state until they relax by photoemission.

Sigma phase transformation in super duplex steel in the range of 900-1050 oC

International Nuclear Information System (INIS)

Garin, J.L; Manheim, R.L; Rios, D

2012-01-01

The embrittlement phenomenon observed in duplex stainless steels obeys to the presence of intermediate phases in the microstructure, principally the so-called sigma-phase, which preferently arises by heating over the range of 540 to 850 o C. The present article describes the dissolution of sigma-phase in welded joints of cast super duplex stainless steels (ASTM A890), at temperatures from 900 to 1050 o C. The experimental procedure utilized usual techniques of quantitative metallography and X-ray diffraction. Annealing of the samples at 850 o C yielded starting contents of sigma of 40,4 % (vol) in the fusion zone and 45,4 % (vol) in the heat-affected zone. The dissolution of the compound was observed after annealing of the specimens at 900, 950, 1.000 and 1.050 o C, with a moderate kinetics at lesser temperatures, while the transformation became fully achieved at 1.050 o C

Sigma models with purely Wess-Zumino-Witten actions

International Nuclear Information System (INIS)

Floreanini, R.; Percacci, R.; Sezgin, E.

1988-11-01

We study the dynamics of sigma models in arbitrary dimensions with purely Wess-Zumino-Witten actions (i.e. without kinetic terms), both from the Lagrangian and Hamiltonian point of view. These models have nontrivial gauge groups which contain the diffeomorphisms of space-time, as well as symmetry groups which in many cases turn out to be infinite dimensional. We give examples in 1,2,3 and 4 space-time dimensions.(author). 9 refs

Landau-Lifshitz sigma-models, fermions and the AdS/CFT correspondence

OpenAIRE

Stefanski Jr, B.

2007-01-01

We define Landau-Lifshitz sigma models on general coset space $G/H$, with $H$ a maximal stability sub-group of $G$. These are non-relativistic models that have $G$-valued N\\"other charges, local $H$ invariance and are classically integrable. Using this definition, we construct the $PSU(2,2|4)/PS(U(2|2)^2)$ Landau-Lifshitz sigma-model. This sigma model describes the thermodynamic limit of the spin-chain Hamiltonian obtained from the complete one-loop dilatation operator of the N=4 super Yang-M...

Massive (p,q)-supersymmetric sigma models revisited

International Nuclear Information System (INIS)

Papadopoulos, G.

1994-06-01

We recently obtained the conditions on the couplings of the general two-dimensional massive sigma-model required by (p,q)-supersymmetry. Here wer compute the Poisson bracket algebra of the supersymmetry and central Noether charges, and show that the action is invariant under the automorphism group of this algebra. Surprisingly, for the (4,4) case the automorphism group is always a subgroup of SO(3), rather than SO(4). We also re-analyse the conditions for (2,2) and 4,4) supersymmetry of the zero torsion models without assumptions about the central charge matrix. (orig.)

Soliton surfaces associated with sigma models: differential and algebraic aspects

International Nuclear Information System (INIS)

Goldstein, P P; Grundland, A M; Post, S

2012-01-01

In this paper, we consider both differential and algebraic properties of surfaces associated with sigma models. It is shown that surfaces defined by the generalized Weierstrass formula for immersion for solutions of the CP N-1 sigma model with finite action, defined in the Riemann sphere, are themselves solutions of the Euler–Lagrange equations for sigma models. On the other hand, we show that the Euler–Lagrange equations for surfaces immersed in the Lie algebra su(N), with conformal coordinates, that are extremals of the area functional, subject to a fixed polynomial identity, are exactly the Euler–Lagrange equations for sigma models. In addition to these differential constraints, the algebraic constraints, in the form of eigenvalues of the immersion functions, are systematically treated. The spectrum of the immersion functions, for different dimensions of the model, as well as its symmetry properties and its transformation under the action of the ladder operators are discussed. Another approach to the dynamics is given, i.e. description in terms of the unitary matrix which diagonalizes both the immersion functions and the projectors constituting the model. (paper)

Strategic management applied to the Six-Sigma suitability appraisal for R&D in FMCG companies = Gestão estratégica aplicada à avaliação da adequação do Six-Sigma para P&D em empresas de bens de consumo

Directory of Open Access Journals (Sweden)

Davidson Lütkenhaus

2016-01-01

Full Text Available This research assesses the suitability of the Six-sigma program for R&D in FMCG companies. The study also includes an analysis of its potential advantages and challenges for this business area. This was performed through data acquisition using a web-based survey targeting large scale multinational companies. Results showed that most R&D personnel within FMCG companies see Six-sigma as a positive methodology for their sector. Roughly 80% of the participants selected time saving and better knowledge allocation as the main advantages of the Six-sigma system. Almost 90% of the survey contributors believe that the series of potential benefits could lead to important scientific breakthroughs. A financial challenge is expected with the implementation and it was said to be the main concern of R&D personnel, especially from those with managerial backgrounds. Cultural changes and scientific obstacles were not reported as imminent threats to the new system. In light of the above, Six-sigma was found to be suitable for R&D in FMCG companies requiring only a few modifications in its standards and a well-defined strategic implementation plan. = Esta pesquisa avalia a adequação do programa Six-Sigma para o setor de P&D em empresas de bens de consumo. O estudo também inclui uma análise das vantagens potenciais e dos desafios para esta área de negócio. Este estudo foi realizado por meio da aquisição de dados, utilizando um questionário online direcionado à profissionais de grandes empresas multinacionais. Os resultados mostraram que a maior parte dos profissionais de P&D nas empresas de FMCG veem o Six-Sigma como uma metodologia positiva para este setor. Cerca de 80% dos participantes selecionados apontam a economia de tempo e a melhor alocação de conhecimento como as principais vantagens do sistema Six-sigma. Quase 90% dos colaboradores da pesquisa acreditam que a série de benefícios potenciais podem levar a descobertas científicas importantes

Aplicação do seis sigma em recursos humanos: um estudo de caso em uma empresa eletro-eletrônica

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Renato Luis de Boer

2010-06-01

Full Text Available Este trabalho apresenta um caso de aplicação da metodologia Seis Sigma na área de recursos humanos de uma empresa de manufatura de componentes eletrônicos. Objetivou-se analisar como a metodologia Seis Sigma foi aplicada e que adaptações se fizeram necessárias para um resultado eficaz. O projeto de Seis Sigma em análise tinha por objetivo a redução da rotatividade de pessoal, ou seja, reduzir o turn over de afastamento. O estudo de caso foi o método de pesquisa utilizado. A estrutura DMAIC (define, measure, analyse, improve and control foi utilizada no desenvolvimento deste projeto de Seis Sigma. As ferramentas foram apropriadas para dados qualitativos. As principais dificuldades relacionaram-se a incoerência entre dados provenientes de diversas fontes, receio de atribuição de culpa pela alta rotatividade de certas funções da empresa e apreensão quanto ao uso de ferramentas típicas do Seis Sigma, fortemente baseadas em estatística e análise quantitativa. O projeto Seis Sigma atingiu as metas estabelecidas além de gerar envolvimento de diversas áreas da empresa com a gestão de pessoas.

Analysis of CPN-1 sigma models via projective structures

International Nuclear Information System (INIS)

Post, S; Grundland, A M

2012-01-01

This paper represents a study of projector solutions to the Euclidean CP N-1 sigma model in two dimensions and their associated surfaces immersed in the su(N) Lie algebra. Any solution for the CP N-1 sigma model defined on the extended complex plane with finite action can be written as a raising operator acting on a holomorphic one. Here the proof is formulated in terms rank-1 projectors so it is explicitly gauge invariant. We apply these results to the analysis of surfaces associated with the CP N-1 models defined using the generalized Weierstrass formula for immersion. We show that the surfaces are conformally parametrized by the Lagrangian density, with finite area equal to the action of the model, and express several other geometrical characteristics of the surface in terms of the physical quantities of the model. Finally, we provide necessary and sufficient conditions that a surface be related to a CP N-1 sigma model

Connection between Einstein equations, nonlinear sigma models, and self-dual Yang-Mills theory

International Nuclear Information System (INIS)

Sanchez, N.; Whiting, B.

1986-01-01

The authors analyze the connection between nonlinear sigma models self-dual Yang-Mills theory, and general relativity (self-dual and non-self-dual, with and without killing vectors), both at the level of the equations and at the level of the different type of solutions (solitons and calorons) of these theories. They give a manifestly gauge invariant formulation of the self-dual gravitational field analogous to that given by Yang for the self-dual Yang-Mills field. This formulation connects in a direct and explicit way the self-dual Yang-Mills and the general relativity equations. They give the ''R gauge'' parametrization of the self-dual gravitational field (which corresponds to modified Yang's-type and Ernst equations) and analyze the correspondence between their different types of solutions. No assumption about the existence of symmetries in the space-time is needed. For the general case (non-self-dual), they show that the Einstein equations contain an O nonlinear sigma model. This connection with the sigma model holds irrespective of the presence of symmetries in the space-time. They found a new class of solutions of Einstein equations depending on holomorphic and antiholomorphic functions and we relate some subclasses of these solutions to solutions of simpler nonlinear field equations that are well known in other branches of physics, like sigma models, SineGordon, and Liouville equations. They include gravitational plane wave solutions. They analyze the response of different accelerated quantum detector models, compare them to the case when the detectors are linterial in an ordinary Planckian gas at a given temperature, and discuss the anisotropy of the detected response for Rindler observers

Topological sigma models on supermanifolds

Energy Technology Data Exchange (ETDEWEB)

Jia, Bei, E-mail: beijia@physics.utexas.edu

2017-02-15

This paper concerns constructing topological sigma models governing maps from semirigid super Riemann surfaces to general target supermanifolds. We define both the A model and B model in this general setup by defining suitable BRST operators and physical observables. Using supersymmetric localization, we express correlation functions in these theories as integrals over suitable supermanifolds. In the case of the A model, we obtain an integral over the supermoduli space of “superinstantons”. The language of supergeometry is used extensively throughout this paper.

Dilaton gravity, Poisson sigma models and loop quantum gravity

International Nuclear Information System (INIS)

Bojowald, Martin; Reyes, Juan D

2009-01-01

Spherically symmetric gravity in Ashtekar variables coupled to Yang-Mills theory in two dimensions and its relation to dilaton gravity and Poisson sigma models are discussed. After introducing its loop quantization, quantum corrections for inverse triad components are shown to provide a consistent deformation without anomalies. The relation to Poisson sigma models provides a covariant action principle of the quantum-corrected theory with effective couplings. Results are also used to provide loop quantizations of spherically symmetric models in arbitrary D spacetime dimensions.

Multi-Agent Modeling in Managing Six Sigma Projects

Directory of Open Access Journals (Sweden)

K. Y. Chau

2009-10-01

Full Text Available In this paper, a multi-agent model is proposed for considering the human resources factor in decision making in relation to the six sigma project. The proposed multi-agent system is expected to increase the acccuracy of project prioritization and to stabilize the human resources service level. A simulation of the proposed multiagent model is conducted. The results show that a multi-agent model which takes into consideration human resources when making decisions about project selection and project team formation is important in enabling efficient and effective project management. The multi-agent modeling approach provides an alternative approach for improving communication and the autonomy of six sigma projects in business organizations.

The algebra of non-local charges in non-linear sigma models

International Nuclear Information System (INIS)

Abdalla, E.; Abdalla, M.C.B.; Brunelli, J.C.; Zadra, A.

1994-01-01

It is derived the complete Dirac algebra satisfied by non-local charges conserved in non-linear sigma models. Some examples of calculation are given for the O(N) symmetry group. The resulting algebra corresponds to a saturated cubic deformation (with only maximum order terms) of the Kac-Moody algebra. The results are generalized for when a Wess-Zumino term be present. In that case the algebra contains a minor order correction (sub-saturation). (author). 1 ref

Supersymmetric sigma models and composite Yang-Mills theory

International Nuclear Information System (INIS)

Lukierski, J.

1980-04-01

We describe two types of supersymmetric sigma models: with field values in supercoset space and with superfields. The notion of Riemannian symmetric pair (H,G/H) is generalized to supergroups. Using the supercoset approach the superconformal-invariant model of composite U(n) Yang-Mills fields in introduced. In the framework of the superfield approach we present with some details two versions of the composite N=1 supersymmetric Yang-Mills theory in four dimensions with U(n) and U(m) x U(n) local invariance. We argue that especially the superfield sigma models can be used for the description of pre-QCD supersymmetric dynamics. (author)

5D-QSAR for spirocyclic sigma1 receptor ligands by Quasar receptor surface modeling.

Science.gov (United States)

Oberdorf, Christoph; Schmidt, Thomas J; Wünsch, Bernhard

2010-07-01

Based on a contiguous and structurally as well as biologically diverse set of 87 sigma(1) ligands, a 5D-QSAR study was conducted in which a quasi-atomistic receptor surface modeling approach (program package Quasar) was applied. The superposition of the ligands was performed with the tool Pharmacophore Elucidation (MOE-package), which takes all conformations of the ligands into account. This procedure led to four pharmacophoric structural elements with aromatic, hydrophobic, cationic and H-bond acceptor properties. Using the aligned structures a 3D-model of the ligand binding site of the sigma(1) receptor was obtained, whose general features are in good agreement with previous assumptions on the receptor structure, but revealed some novel insights since it represents the receptor surface in more detail. Thus, e.g., our model indicates the presence of an H-bond acceptor moiety in the binding site as counterpart to the ligands' cationic ammonium center, rather than a negatively charged carboxylate group. The presented QSAR model is statistically valid and represents the biological data of all tested compounds, including a test set of 21 ligands not used in the modeling process, with very good to excellent accuracy [q(2) (training set, n=66; leave 1/3 out) = 0.84, p(2) (test set, n=21)=0.64]. Moreover, the binding affinities of 13 further spirocyclic sigma(1) ligands were predicted with reasonable accuracy (mean deviation in pK(i) approximately 0.8). Thus, in addition to novel insights into the requirements for binding of spirocyclic piperidines to the sigma(1) receptor, the presented model can be used successfully in the rational design of new sigma(1) ligands. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Expression of the sigma35 and cry2AB genes involved in Bacillus thuringiensis virulence Expressão dos genes sigma35 e cry2AB envolvidos na virulência de Bacillus thuringiensis

Directory of Open Access Journals (Sweden)

Ana Maria Guidelli-Thuler

2009-06-01

Full Text Available There are several genes involved in Bacillus thuringiensis sporulation. The regulation and expression of these genes results in an upregulation in Cry protein production, and this is responsible for the death of insect larvae infected by Bacillus thuringiensis. Gene expression was monitored in Bacillus thuringiensis during three developmental phases. DNA macroarrays were constructed for selected genes whose sequences are available in the GenBank database. These genes were hybridized to cDNA sequences from B. thuringiensis var. kurstaki HD-1. cDNA probes were synthesized by reverse transcription from B. thuringiensis RNA templates extracted during the exponential (log growth, stationary and sporulation phases, and labeled with 33PadCTP. Two genes were differentially expressed levels during the different developmental phases. One of these genes is related to sigma factor (sigma35, and the other is a cry gene (cry2Ab. There were differences between the differential levels of expression of various genes and among the expression detected for different combinations of the sigma factor and cry2Ab genes. The maximum difference in expression was observed for the gene encoding sigma35 factor in the log phase, which was also expressed at a high level during the sporulation phase. The cry2Ab gene was only expressed at a high level in the log phase, but at very low levels in the other phases when compared to the sigma35.Muitos genes estão envolvidos nos mecanismos de esporulação da bactéria Bacillus thuringiensis. A regulação e expressão desses genes resultam em uma produção massiva da proteína Cry, responsável pela morte das larvas de muitos insetos. Neste trabalho monitorou-se a expressão de genes de Bacillus thuringiensis, ao longo de três fases de seu desenvolvimento. Foram construídos macroarrays de DNA dos genes selecionados, cujas seqüências estão disponibilizadas no GenBank. Estes genes foram hibridizados com cDNAs obtidos de B

Investigation of N2O Production from 266 and 532 nm Laser Flash Photolysis of O3/N2/O2 Mixtures

Science.gov (United States)

Estupinan, E. G.; Nicovich, J. M.; Li, J.; Cunnold, D. M.; Wine, P. H.

2002-01-01

Tunable diode laser absorption spectroscopy has been employed to measure the amount of N2O produced from laser flash photolysis of O3/N2/O2 mixtures at 266 and 532 nm. In the 532 nm photolysis experiments very little N2O is observed, thus allowing an upper limit yield of 7 x 10(exp -8) to be established for the process O3 + N2 yield N2O + O2, where O3 is nascent O3 that is newly formed via O(3P(sub J)) + O2 recombination (with vibrational excitation near the dissociation energy of O3). The measured upper limit yield is a factor of approx. 600 smaller than a previous literature value and is approximately a factor of 10 below the threshold for atmospheric importance. In the 266 nm photolysis experiments, significant N2O production is observed and the N2O quantum yield is found to increase linearly with pressure over the range 100 - 900 Torr in air bath gas. The source of N2O in the 266 nm photolysis experiments is believed to be the addition reaction O(1D(sub 2)) + N2 + M yields (k(sub sigma)) N2O + M, although reaction of (very short-lived) electronically excited O3 with N2 cannot be ruled out by the available data. Assuming that all observed N2O comes from the O(1D(sub 2)) + N2 + M reaction, the following expression describes the temperature dependence of k(sub sigma) (in its third-order low-pressure limit) that is consistent with the N2O yield data: k(sub sigma) = (2.8 +/- 0.1) x 10(exp -36)(T/300)(sup -(0-88+0.36)) cm(sup 6) molecule(sup -2)/s, where the uncertainties are 2(sigma) and represent precision only. The accuracy of the reported rate coefficients at the 95% confidence level is estimated to be 30 - 40% depending on the temperature. Model calculations suggest that gas phase processes initiated by ozone absorption of a UV photon represent about 1.4% of the currently estimated global source strength of atmospheric N2O. However, these processes could account for a significant fraction of the oxygen mass-independent enrichment observed in atmospheric N2O, and

Dynamical simulation of a linear sigma model near the critical point

Energy Technology Data Exchange (ETDEWEB)

Wesp, Christian; Meistrenko, Alex; Greiner, Carsten [Institut fuer Theoretische Physik, Goethe-Universitaet Frankfurt, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany); Hees, Hendrik van [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, D-60438 Frankfurt (Germany)

2014-07-01

The intention of this study is the search for signatures of the chiral phase transition. To investigate the impact of fluctuations, e.g. of the baryon number, on the transition or a critical point, the linear sigma model is treated in a dynamical 3+1D numerical simulation. Chiral fields are approximated as classical fields, quarks are described by quasi particles in a Vlasov equation. Additional dynamic is implemented by quark-quark and quark-sigma-field interaction. For a consistent description of field-particle interactions, a new Monte-Carlo-Langevin-like formalism has been developed and is discussed.

Can a Linear Sigma Model Describe Walking Gauge Theories at Low Energies?

Science.gov (United States)

Gasbarro, Andrew

2018-03-01

In recent years, many investigations of confining Yang Mills gauge theories near the edge of the conformal window have been carried out using lattice techniques. These studies have revealed that the spectrum of hadrons in nearly conformal ("walking") gauge theories differs significantly from the QCD spectrum. In particular, a light singlet scalar appears in the spectrum which is nearly degenerate with the PNGBs at the lightest currently accessible quark masses. This state is a viable candidate for a composite Higgs boson. Presently, an acceptable effective field theory (EFT) description of the light states in walking theories has not been established. Such an EFT would be useful for performing chiral extrapolations of lattice data and for serving as a bridge between lattice calculations and phenomenology. It has been shown that the chiral Lagrangian fails to describe the IR dynamics of a theory near the edge of the conformal window. Here we assess a linear sigma model as an alternate EFT description by performing explicit chiral fits to lattice data. In a combined fit to the Goldstone (pion) mass and decay constant, a tree level linear sigma model has a Χ2/d.o.f. = 0.5 compared to Χ2/d.o.f. = 29.6 from fitting nextto-leading order chiral perturbation theory. When the 0++ (σ) mass is included in the fit, Χ2/d.o.f. = 4.9. We remark on future directions for providing better fits to the σ mass.

Estudo da variabilidade da viscosidade na produção de lotes de tintas : um projeto Seis Sigma

OpenAIRE

Vivian Sebben Adami

2002-01-01

Este trabalho de conclusão tem como tema a Qualidade Seis Sigma e a produção de tintas, com foco no parâmetro viscosidade. O objetivo principal é o estudo da variabilidade da viscosidade das tintas, com vistas à diminuição do número de desvios de viscosidade de lotes de produção e, conseqüentemente, do retrabalho e lead-time fabril. Inicialmente, foi realizada uma revisão bibliográfica sobre a metodologia Seis Sigma, suas principais ferramentas, e sobre os processos de produção de tintas, sua...

Finiteness of Ricci flat supersymmetric non-linear sigma-models

International Nuclear Information System (INIS)

Alvarez-Gaume, L.; Ginsparg, P.

1985-01-01

Combining the constraints of Kaehler differential geometry with the universality of the normal coordinate expansion in the background field method, we study the ultraviolet behavior of 2-dimensional supersymmetric non-linear sigma-models with target space an arbitrary riemannian manifold M. We show that the constraint of N=2 supersymmetry requires that all counterterms to the metric beyond one-loop order are cohomologically trivial. It follows that such supersymmetric non-linear sigma-models defined on locally symmetric spaces are super-renormalizable and that N=4 models are on-shell ultraviolet finite to all orders of perturbation theory. (orig.)

Loop calculations in quantum-mechanical non-linear sigma models sigma models with fermions and applications to anomalies

NARCIS (Netherlands)

Boer, Jan de; Peeters, Bas; Skenderis, Kostas; Nieuwenhuizen, Peter van

1995-01-01

We construct the path integral for one-dimensional non-linear sigma models, starting from a given Hamiltonian operator and states in a Hilbert space. By explicit evaluation of the discretized propagators and vertices we find the correct Feynman rules which differ from those often assumed. These

Análise comparativa da aplicação do programa Seis Sigma em processos de manufatura e serviços Comparative analyses of Six-Sigma program application in manufacturing and services process

Directory of Open Access Journals (Sweden)

Luis Ricardo Galvani

2013-01-01

Full Text Available O programa Seis Sigma nasceu e evoluiu em ambiente de manufatura, mas também pode ser utilizado em processos de serviços. Porém sua utilização nesse ambiente tem sido feita de forma mais modesta, com menor participação de empresas e, consequentemente, menor número de casos e relatos divulgados. Este trabalho buscou comparar e analisar a aplicação do programa Seis Sigma em manufatura e serviços, por meio de revisão da literatura, análise de projetos vivenciados pelo autor e pesquisa de campo em empresas praticantes do programa. Apesar da limitação da amostra, os resultados mostram fortes indícios de diferenças significativas cuja melhor compreensão pode ajudar a obter melhores resultados em aplicações em serviços.The Six-sigma program has its roots in the manufacturing field, but it can be applied to a service process. However, this application has been done in a modest manner, with the participation of few companies and, as a consequence, few cases, projects, and papers have been exposed. This paper presents a comparative analysis of Six-sigma program application in manufacturing and services process by literature review, comparative analyses of Six-sigma projects experienced by the author, and case studies with companies that apply the program in the manufacturing and services field. Even with sample restriction, the results show key differences that can lead to benefits to services application.

Harmonicity in supermanifolds and sigma models

International Nuclear Information System (INIS)

Munoz-Masque, Jaime; Vallejo, Jose A.

2009-01-01

We show that given an odd metric G on a supermanifold (M, A) and its associated Laplacian Δ, it is possible to interpret harmonic superfunctions (i.e., those f is an element of A such that Δf = 0) as solutions to a variational problem describing a supersymmetric sigma model.

Integrability of a family of quantum field theories related to sigma models

Energy Technology Data Exchange (ETDEWEB)

Ridout, David [Australian National Univ., Canberra, ACT (Australia). Dept. of Theoretical Physics; DESY, Hamburg (Germany). Theory Group; Teschner, Joerg [DESY, Hamburg (Germany). Theory Group

2011-03-15

A method is introduced for constructing lattice discretizations of large classes of integrable quantum field theories. The method proceeds in two steps: The quantum algebraic structure underlying the integrability of the model is determined from the algebra of the interaction terms in the light-cone representation. The representation theory of the relevant quantum algebra is then used to construct the basic ingredients of the quantum inverse scattering method, the lattice Lax matrices and R-matrices. This method is illustrated with four examples: The Sinh-Gordon model, the affine sl(3) Toda model, a model called the fermionic sl(2 vertical stroke 1) Toda theory, and the N=2 supersymmetric Sine-Gordon model. These models are all related to sigma models in various ways. The N=2 supersymmetric Sine-Gordon model, in particular, describes the Pohlmeyer reduction of string theory on AdS{sub 2} x S{sup 2}, and is dual to a supersymmetric non-linear sigma model with a sausage-shaped target space. (orig.)

Sphaleron in a non-linear sigma model

International Nuclear Information System (INIS)

Sogo, Kiyoshi; Fujimoto, Yasushi.

1989-08-01

We present an exact classical saddle point solution in a non-linear sigma model. It has a topological charge 1/2 and mediates the vacuum transition. The quantum fluctuations and the transition rate are also examined. (author)

Sigma models in (4,4) harmonic superspace

International Nuclear Information System (INIS)

Ivanov, E.; Joint Inst. for Nuclear Research, Dubna; Sutulin, A.

1994-04-01

We define basics of (4,4) 2D harmonic superspace with two independent sets of SU(2) harmonic variables and apply it to construct new superfield actions of (4,4) supersymmetric two-dimensional sigma models with torsion and mutually commuting left and right complex structures, as well as of their massive deformations. We show that the generic off-shell sigma model action is the general action of constrained analytic superfields q (1,1) representing twisted N=4 multiplets in (4,4) harmonic superspace. The massive term of q (1,1) is shown to be unique; it generates a scalar potential the form of which is determined by the metric on the target bosonic manifold. We discuss in detail (4,4) supersymmetric group manifold SU(2)xU(1) WZNW sigma model and its Liouville deformation. A deep analogy of the relevant superconformally invariant analytic superfield action to that of the improved tensor N=2 4D multiplet is found. We define (4,4) duality transformation and find new off-shell dual representations of the previously constructed actions via unconstrained analytic (4,4) superfields. The main peculiarities of the (4,4) duality transformation are: (i) It preserves manifest (4,4) supersymmetry; (ii) dual actions reveal a gauge invariance needed for the onshell equivalence to the original description; (iii) in the actions dual to the massive ones 2D supersymmetry is modified off shell by SU(2) tensor central charges. The dual representation suggests some hints of how to describe (4,4) models with non-commuting complex structures in the harmonic superspace. (orig.)

Classical solutions of non-linear sigma-models and their quantum fluctuations

International Nuclear Information System (INIS)

Din, A.M.

1980-05-01

I study the properties of O(N) and CPsup(n-1) non-linear sigma-models in the two dimensional Euclidean space. All classical solutions of the equations of motion can be characterized and in the CPsup(n-1) model they can be expressed in a simple and explicit way in terms of holomorphic vectors. The topological winding number and the action of the general CPsup(n-1) solution can be evaluated and the latter turns out always to be a integer multiple of 2π. I further discuss the stability of the solutions and the problem of one-loop calculations of quantum fluctuations around classical solutions

Background field method in gauge theories and on linear sigma models

International Nuclear Information System (INIS)

van de Ven, A.E.M.

1986-01-01

This dissertation constitutes a study of the ultraviolet behavior of gauge theories and two-dimensional nonlinear sigma-models by means of the background field method. After a general introduction in chapter 1, chapter 2 presents algorithms which generate the divergent terms in the effective action at one-loop for arbitrary quantum field theories in flat spacetime of dimension d ≤ 11. It is demonstrated that global N = 1 supersymmetric Yang-Mills theory in six dimensions in one-loop UV-finite. Chapter 3 presents an algorithm which produces the divergent terms in the effective action at two-loops for renormalizable quantum field theories in a curved four-dimensional background spacetime. Chapter 4 presents a study of the two-loop UV-behavior of two-dimensional bosonic and supersymmetric non-linear sigma-models which include a Wess-Zumino-Witten term. It is found that, to this order, supersymmetric models on quasi-Ricci flat spaces are UV-finite and the β-functions for the bosonic model depend only on torsionful curvatures. Chapter 5 summarizes a superspace calculation of the four-loop β-function for two-dimensional N = 1 and N = 2 supersymmetric non-linear sigma-models. It is found that besides the one-loop contribution which vanishes on Ricci-flat spaces, the β-function receives four-loop contributions which do not vanish in the Ricci-flat case. Implications for superstrings are discussed. Chapters 6 and 7 treat the details of these calculations

Note on off-shell relations in nonlinear sigma model

International Nuclear Information System (INIS)

Chen, Gang; Du, Yi-Jian; Li, Shuyi; Liu, Hanqing

2015-01-01

In this note, we investigate relations between tree-level off-shell currents in nonlinear sigma model. Under Cayley parametrization, all odd-point currents vanish. We propose and prove a generalized U(1) identity for even-point currents. The off-shell U(1) identity given in http://dx.doi.org/10.1007/JHEP01(2014)061 is a special case of the generalized identity studied in this note. The on-shell limit of this identity is equivalent with the on-shell KK relation. Thus this relation provides the full off-shell correspondence of tree-level KK relation in nonlinear sigma model.

Branes in Poisson sigma models

International Nuclear Information System (INIS)

Falceto, Fernando

2010-01-01

In this review we discuss possible boundary conditions (branes) for the Poisson sigma model. We show how to carry out the perturbative quantization in the presence of a general pre-Poisson brane and how this is related to the deformation quantization of Poisson structures. We conclude with an open problem: the perturbative quantization of the system when the boundary has several connected components and we use a different pre-Poisson brane in every component.

The point of 6 sigma

International Nuclear Information System (INIS)

An, Yeong Jin

2000-07-01

This book gives descriptions of the point of 6 sigma. These are the titles of this : what 6 sigma is, sigma conception, motor roller 3.4 ppm, centering error, 6 sigma purpose, 6 sigma principle, eight steps of innovation strategy, 6 sigma innovation strategy of easy system step, measurement standard of 6 sigma outcome, the main role of 6 sigma, acknowledgment and reword, 6 sigma characteristic, 6 sigma effect, 6 sigma application and problems which happen when 6 sigma introduces.

LEAN SIX SIGMA – MULTIPLE CASE STUDY

Directory of Open Access Journals (Sweden)

Delvio Venanzi

2017-12-01

Full Text Available Lean Six Sigma é uma gestão focada na qualidade e desempenho produtivo em sistemas operacionais. Este artigo discute os fundamentos desta metodologia através de duas diferentes concepções de gestão, Lean Manufacturing e Six Sigma. Primeiro, o artigo explica o DMAIC (definir, medir, analisar, melhorar e controlar e suas respectivas fases, após a filosofia Lean com o sipoc e técnicas de mapeamento de fluxo de valor. O artigo pretende mostrar a integração destes dois conceitos e seus resultados. A metodologia consistiu em uma teoria baseada em uma pesquisa bibliográfica de pesquisa exploratória que consistiu de três estudos de caso em empresas de diferenças localizadas em Sorocaba, São Paulo. Neste artigo estuda a aplicação de Lean Seis Sigma e seus resultados.

Some examples of instantons in sigma models

International Nuclear Information System (INIS)

Kogan, Ya.; Markushevich, D.; Morozov, A.; Ol'shanetskij, M.; Perelomov, A.; Roslyj, A.

1988-01-01

Holomorphic instantons of arbitrary generation in manifolds and their boson and fermion zero modes are determined within the scope of the sigma model. General formulae for their quantitative evaluation are presented. Zero modes of spherical and toroidal instantons are discussed in detail

Adoção do Six Sigma pelas 500 Maiores Empresas em Portugal

OpenAIRE

Conceição, A.; Major, M.

2011-01-01

The Six Sigma had its genesis in big industrial companies that have implemented it as a tool for reducing defects. The initial success encouraged its application in other areas and we see today successful implementation in other sectors such as services, and within their own organizations in other areas beyond production, setting; this has contributed to Six Sigma being recognized as a new management model. In order to determine the extent to which Six Sigma is present in Portuguese companies...

Cohomological reduction of sigma models

Energy Technology Data Exchange (ETDEWEB)

Candu, Constantin; Mitev, Vladimir; Schomerus, Volker [DESY, Hamburg (Germany). Theory Group; Creutzig, Thomas [North Carolina Univ., Chapel Hill, NC (United States). Dept. of Physics and Astronomy

2010-01-15

This article studies some features of quantum field theories with internal supersymmetry, focusing mainly on 2-dimensional non-linear sigma models which take values in a coset superspace. It is discussed how BRST operators from the target space super- symmetry algebra can be used to identify subsectors which are often simpler than the original model and may allow for an explicit computation of correlation functions. After an extensive discussion of the general reduction scheme, we present a number of interesting examples, including symmetric superspaces G/G{sup Z{sub 2}} and coset superspaces of the form G/G{sup Z{sub 4}}. (orig.)

New classical r-matrices from integrable non-linear sigma-models

International Nuclear Information System (INIS)

Laartz, J.; Bordemann, M.; Forger, M.; Schaper, U.

1993-01-01

Non-linear sigma models on Riemannian symmetric spaces constitute the most general class of classical non-linear sigma models which are known to be integrable. Using the current algebra structure of these models their canonical structure is analyzed and it is shown that their non-ultralocal fundamental Poisson bracket relation is governed by a field dependent non antisymmetric r-matrix obeying a dynamical Yang Baxter equation. The fundamental Poisson bracket relations and the r-matrix are derived explicitly and a new kind of algebra is found that is supposed to replace the classical Yang Baxter algebra governing the canonical structure of ultralocal models. (Author) 9 refs

Topological Poisson Sigma models on Poisson-Lie groups

International Nuclear Information System (INIS)

Calvo, Ivan; Falceto, Fernando; Garcia-Alvarez, David

2003-01-01

We solve the topological Poisson Sigma model for a Poisson-Lie group G and its dual G*. We show that the gauge symmetry for each model is given by its dual group that acts by dressing transformations on the target. The resolution of both models in the open geometry reveals that there exists a map from the reduced phase of each model (P and P*) to the main symplectic leaf of the Heisenberg double (D 0 ) such that the symplectic forms on P, P* are obtained as the pull-back by those maps of the symplectic structure on D 0 . This uncovers a duality between P and P* under the exchange of bulk degrees of freedom of one model with boundary degrees of freedom of the other one. We finally solve the Poisson Sigma model for the Poisson structure on G given by a pair of r-matrices that generalizes the Poisson-Lie case. The Hamiltonian analysis of the theory requires the introduction of a deformation of the Heisenberg double. (author)

The coupling of Poisson sigma models to topological backgrounds

Energy Technology Data Exchange (ETDEWEB)

Rosa, Dario [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of)

2016-12-13

We extend the coupling to the topological backgrounds, recently worked out for the 2-dimensional BF-model, to the most general Poisson sigma models. The coupling involves the choice of a Casimir function on the target manifold and modifies the BRST transformations. This in turn induces a change in the BRST cohomology of the resulting theory. The observables of the coupled theory are analyzed and their geometrical interpretation is given. We finally couple the theory to 2-dimensional topological gravity: this is the first step to study a topological string theory in propagation on a Poisson manifold. As an application, we show that the gauge-fixed vectorial supersymmetry of the Poisson sigma models has a natural explanation in terms of the theory coupled to topological gravity.

Heterotic non-linear sigma models with anti-de Sitter target spaces

International Nuclear Information System (INIS)

Michalogiorgakis, Georgios; Gubser, Steven S.

2006-01-01

We calculate the beta function of non-linear sigma models with S D+1 and AdS D+1 target spaces in a 1/D expansion up to order 1/D 2 and to all orders in α ' . This beta function encodes partial information about the spacetime effective action for the heterotic string to all orders in α ' . We argue that a zero of the beta function, corresponding to a worldsheet CFT with AdS D+1 target space, arises from competition between the one-loop and higher-loop terms, similarly to the bosonic and supersymmetric cases studied previously in [J.J. Friess, S.S. Gubser, Non-linear sigma models with anti-de Sitter target spaces, Nucl. Phys. B 750 (2006) 111-141]. Various critical exponents of the non-linear sigma model are calculated, and checks of the calculation are presented

Differential labeling of dopamine and sigma sites by [3H]nemonapride and [3H]raclopride in postmortem human brains.

Science.gov (United States)

Tang, S W; Helmeste, D M; Fang, H; Li, M; Vu, R; Bunney, W; Potkin, S; Jones, E G

1997-08-08

The difference between the binding of [3H]nemonapride and [3H]raclopride has been used to quantify dopamine D4 receptors in postmortem schizophrenic brain studies. Recent work, however, has suggested that at least part of the differential between [3H]nemonapride and [3H]raclopride binding may represent sigma rather than D4 receptor sites. We applied the nemonapride-raclopride subtraction method to postmortem, non-schizophrenic human striatum to examine the variation in dopaminergic receptor binding labeled by these ligands. Variation in sigma receptor binding labeled by [3H]nemonapride was studied in frontal cortex, striatum and cerebellum. Specific binding was defined by sulpiride (dopamine receptor ligand), PPAP (sigma receptor ligand) and haloperidol (mixed dopaminergic/sigma agent), respectively. Haloperidol defined a combination of sites, which were approximately the sum of the dopaminergic and sigma components defined by sulpiride and PPAP, respectively. Significant inter-individual variation in the amount of specific binding for dopaminergic and sigma receptor sites was observed. However, no significant nor consistent observation of striatal dopamine D4 receptors or D4-like binding sites was observed in the striatum even though two independent sets of tissues, with different dissections were used. The inconsistencies in some previous postmortem studies appear to be at least partially explained by the inclusion of both sigma and dopaminergic components in [3H]nemonapride binding and the inherent high inter-individual variability of the different components.

Generalized Mathai-Quillen Topological Sigma Models

OpenAIRE

Llatas, Pablo M.

1995-01-01

A simple field theoretical approach to Mathai-Quillen topological field theories of maps $X: M_I \\to M_T$ from an internal space to a target space is presented. As an example of applications of our formalism we compute by applying our formulas the action and Q-variations of the fields of two well known topological systems: Topological Quantum Mechanics and type-A topological Sigma Model.

Baryon and meson phenomenology in the extended Linear Sigma Model

Energy Technology Data Exchange (ETDEWEB)

Giacosa, Francesco; Habersetzer, Anja; Teilab, Khaled; Eshraim, Walaa; Divotgey, Florian; Olbrich, Lisa; Gallas, Susanna; Wolkanowski, Thomas; Janowski, Stanislaus; Heinz, Achim; Deinet, Werner; Rischke, Dirk H. [Institute for Theoretical Physics, J. W. Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Kovacs, Peter; Wolf, Gyuri [Institute for Particle and Nuclear Physics, Wigner Research Center for Physics, Hungarian Academy of Sciences, H-1525 Budapest (Hungary); Parganlija, Denis [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)

2014-07-01

The vacuum phenomenology obtained within the so-called extended Linear Sigma Model (eLSM) is presented. The eLSM Lagrangian is constructed by including from the very beginning vector and axial-vector d.o.f., and by requiring dilatation invariance and chiral symmetry. After a general introduction of the approach, particular attention is devoted to the latest results. In the mesonic sector the strong decays of the scalar and the pseudoscalar glueballs, the weak decays of the tau lepton into vector and axial-vector mesons, and the description of masses and decays of charmed mesons are shown. In the baryonic sector the omega production in proton-proton scattering and the inclusion of baryons with strangeness are described.

The classical r-matrix method for nonlinear sigma-model

OpenAIRE

Sevostyanov, Alexey

1995-01-01

The canonical Poisson structure of nonlinear sigma-model is presented as a Lie-Poisson r-matrix bracket on coadjoint orbits. It is shown that the Poisson structure of this model is determined by some `hidden singularities' of the Lax matrix.

Description of surfaces associated with Grassmannian sigma models on Minkowski space

International Nuclear Information System (INIS)

Grundland, A.M.; Snobl, L.

2005-01-01

We construct and investigate smooth orientable surfaces in su(N) algebras. The structural equations of surfaces associated with Grassmannian sigma models on Minkowski space are studied using moving frames adapted to the surfaces. The first and second fundamental forms of these surfaces as well as the relations between them as expressed in the Gauss-Weingarten and Gauss-Codazzi-Ricci equations are found. The scalar curvature and the mean curvature vector expressed in terms of a solution of Grassmanian sigma model are obtained

Brane solutions of a spherical sigma model in six dimensions

International Nuclear Information System (INIS)

Lee, Hyun Min; Papazoglou, Antonios

2005-01-01

We explore solutions of six-dimensional gravity coupled to a non-linear sigma model, in the presence of codimension-two branes. We investigate the compactifications induced by a spherical scalar manifold and analyze the conditions under which they are of finite volume and singularity free. We discuss the issue of single-valuedness of the scalar fields and provide some special embedding of the scalar manifold to the internal space which solves this problem. These brane solutions furnish some self-tuning features, however they do not provide a satisfactory explanation of the vanishing of the effective four-dimensional cosmological constant. We discuss the properties of this model in relation with the self-tuning example based on a hyperbolic sigma model

Observation of the Heavy Baryons Sigma b and Sigma b*.

Science.gov (United States)

Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

2007-11-16

We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.

The algebra of non-local charges in non-linear sigma models

International Nuclear Information System (INIS)

Abdalla, E.; Abdalla, M.C.B.; Brunelli, J.C.; Zadra, A.

1993-07-01

We obtain the exact Dirac algebra obeyed by the conserved non-local charges in bosonic non-linear sigma models. Part of the computation is specialized for a symmetry group O(N). As it turns out the algebra corresponds to a cubic deformation of the Kac-Moody algebra. The non-linear terms are computed in closed form. In each Dirac bracket we only find highest order terms (as explained in the paper), defining a saturated algebra. We generalize the results for the presence of a Wess-Zumino term. The algebra is very similar to the previous one, containing now a calculable correction of order one unit lower. (author). 22 refs, 5 figs

Phase diagram and EXAFS study of La sub 0 sub . sub 7 Ca sub 0 sub . sub 3 sub - sub x Ba sub x MnO sub 3 manganites

CERN Document Server

Ulyanov, A N; Yang, D S

2003-01-01

The phase diagram and local structure of La sub 0 sub . sub 7 Ca sub 0 sub . sub 3 sub - sub x Ba sub x MnO sub 3 (x=0; 0.03; 0.06; ... 0.3) lanthanum manganites were studies. The Curie temperature, T sub c , of the compositions showed a sharp change near the concentrational structural orthorhombic-rhombohedral phase transition. Maximums of dispersion, sigma sub M sub n sub - sub O sup 2 , and asymmetry, sigma M sub n sub - sub O sup 3 , of pair distribution function for the Mn-O bond distances of MnO sub 6 octahedron on x-dependence were observed by extended X-ray absorption fine structure (EXAFS) analysis. The maximum of sigma sub M sub n sub - sub O sup 2 is caused by increase of dynamic rms displacements of Mn-O bond distances near the T sub c. The observed x dependence of sigma sub M sub n sub - sub O sup 3 reflects the reduction of charge carriers mobility at approaching to T sub c. (author)

Low-energy limit of the extended Linear Sigma Model

Energy Technology Data Exchange (ETDEWEB)

Divotgey, Florian [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Kovacs, Peter [Wigner Research Center for Physics, Hungarian Academy of Sciences, Institute for Particle and Nuclear Physics, Budapest (Hungary); GSI Helmholtzzentrum fuer Schwerionenforschung, ExtreMe Matter Institute, Darmstadt (Germany); Giacosa, Francesco [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Jan-Kochanowski University, Institute of Physics, Kielce (Poland); Rischke, Dirk H. [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); University of Science and Technology of China, Interdisciplinary Center for Theoretical Study and Department of Modern Physics, Hefei, Anhui (China)

2018-01-15

The extended Linear Sigma Model is an effective hadronic model based on the linear realization of chiral symmetry SU(N{sub f}){sub L} x SU(N{sub f}){sub R}, with (pseudo)scalar and (axial-)vector mesons as degrees of freedom. In this paper, we study the low-energy limit of the extended Linear Sigma Model (eLSM) for N{sub f} = flavors by integrating out all fields except for the pions, the (pseudo-)Nambu-Goldstone bosons of chiral symmetry breaking. The resulting low-energy effective action is identical to Chiral Perturbation Theory (ChPT) after choosing a representative for the coset space generated by chiral symmetry breaking and expanding it in powers of (derivatives of) the pion fields. The tree-level values of the coupling constants of the effective low-energy action agree remarkably well with those of ChPT. (orig.)

Sigma-model formulation of the Yang-Mills theory on four-dimensional hypersphere

International Nuclear Information System (INIS)

Ivanov, E.A.; Krivonos, S.O.

1981-01-01

The bilocal sigma-model representation is constructed for the Yang-Mills theory in the simplest conformally flat hyperspherical spaces So(1,4)/SO(1,3), SO(2,3)/SO(1,3) and SO(5)/SO(4). Like in the case of Minkowski and Euclidean spaces, Yang-Mills potential is defined as bsub(μ)(x)=dsub(μ)sup(y)b(x,y)|y=0 , b(x,y) being a bilocal Goldstone field which takes values in the gauge group algebra and is subjected to certain covariant constraints. The minimal version of these constraints results in the ''string'' representation for b(x,y) through the P-exponential of bsub(μ)(x) along the fixed paths coinciding with geodesics. Due to the presence of closed geodesics, the contour fuctionals naturally appear in the theory, with contours being the circles with the hypersphere radius. The sigma-model representation is shown to be Weyl-covariant: its formulations indifferent conformally flat spaces are related by transformations of ysup(rho). The geometric meaning of ysup(rho) and minimal constraints is explained, and the conformal group gransformation for ysup(rho) is found [ru

Sigma-model formulation of the Yang-Mills theory on four-dimensional hypersphere

International Nuclear Information System (INIS)

Ivanov, E.A.; Krivonos, S.O.

1983-01-01

The bilocal sigma-model representation is constructed for Yang-Mills theory in the simplest conformally flat hyperspherical spases SO(1, 4)/SO(1, 3), SO(2, 3)/SO(1, 3) and SO(5)/SO(4) (for the Euclidean Yang-Mills). Like in the case of Minkowski and Euclidean spaces, Yang-Mills potential is defined as bsub(μ)(x)=dsub(μ)sup(y)b(x, y)sub(y=0), b(x, y) being a bilocal Goldstone field which takes values in the gauge group algebra and is subjected to certain covariant constraints. The minimal version of these constraints results in the ''string'' representation for b(x, y) through the P exponential of bsub(μ)(x) along the fixed paths coinciding with geodesics. Due to the presence of closed geodesics, the contour functional naturally appear in the theory, with contours being the circles with the hypersphere radius. The sigma-model representation is shown to be Weyl-covariant: its formulations in different conformally flat spaces are related by transformations of ysup(rho). The geometric meaning ysup(rho) and minimal constraints is explained, and the conformal group transofrmation of ysup(rho) is found

The hyper-Kaehler supersymmetric sigma-model in six dimensions

International Nuclear Information System (INIS)

Sierra, G.; Townsend, P.K.

1983-01-01

The maximally supersymmetric, hyper-Kaehler, sigma-model is given in six-dimensional superfield form. The hyper-Kaehler condition follows from the requirements that the equations of motion be derivable from an action. (orig.)

Structure of the discrete Dirac vacuum in the sigma + omega model

International Nuclear Information System (INIS)

Miller, L.D.

1989-01-01

The sigma + omega model potentials imply that any moderate to large nucleus should have thousands of discrete negative-energy nucleon states. Theoretical predictions of structure in this discrete island of the nuclear Dirac sea are presented in this paper. This structure is related to the spectral functions that will emerge in high energy electron- and hardon-induced reactions on nuclei. These high-energy reaction studies should supplement our understanding of the saturation mechanism of the sigma + omega model. They could also identify the threshold for observable quantum chromo-dynamics (QCD) effects in nuclei

General classical solutions of the complex Grassmannian and CP sub(N-1) sigma models

International Nuclear Information System (INIS)

Sasaki, Ryu.

1983-05-01

General classical solutions are constructed for the complex Grassmannian non-linear sigma models in two euclidean dimensions in terms of holomorphic functions. The Grassmannian sigma models are a simple generalization of the well known CP sup(N-1) model in two dimensions and they share various interesting properties; existence of (anti-) instantons, an infinite number of conserved quantities and complete integrability. (author)

Current algebra of classical non-linear sigma models

International Nuclear Information System (INIS)

Forger, M.; Laartz, J.; Schaeper, U.

1992-01-01

The current algebra of classical non-linear sigma models on arbitrary Riemannian manifolds is analyzed. It is found that introducing, in addition to the Noether current j μ associated with the global symmetry of the theory, a composite scalar field j, the algebra closes under Poisson brackets. (orig.)

A review of Lean Six Sigma deployment and maturity models

NARCIS (Netherlands)

Lameijer, B.A.; de Mast, J.; Does, R.J.M.M.

2017-01-01

For guidance in implementing Lean Six Sigma (LSS), both the academic and the practitioners’ literature offer deployment models and models for assessing the implementation’s maturity. This paper makes a critical appraisal of the quality and usefulness of a sample of 19 such models. The appraisal

Algebraic Structure of tt * Equations for Calabi-Yau Sigma Models

Science.gov (United States)

Alim, Murad

2017-08-01

The tt * equations define a flat connection on the moduli spaces of {2d, \\mathcal{N}=2} quantum field theories. For conformal theories with c = 3 d, which can be realized as nonlinear sigma models into Calabi-Yau d-folds, this flat connection is equivalent to special geometry for threefolds and to its analogs in other dimensions. We show that the non-holomorphic content of the tt * equations, restricted to the conformal directions, in the cases d = 1, 2, 3 is captured in terms of finitely many generators of special functions, which close under derivatives. The generators are understood as coordinates on a larger moduli space. This space parameterizes a freedom in choosing representatives of the chiral ring while preserving a constant topological metric. Geometrically, the freedom corresponds to a choice of forms on the target space respecting the Hodge filtration and having a constant pairing. Linear combinations of vector fields on that space are identified with the generators of a Lie algebra. This Lie algebra replaces the non-holomorphic derivatives of tt * and provides these with a finer and algebraic meaning. For sigma models into lattice polarized K3 manifolds, the differential ring of special functions on the moduli space is constructed, extending known structures for d = 1 and 3. The generators of the differential rings of special functions are given by quasi-modular forms for d = 1 and their generalizations in d = 2, 3. Some explicit examples are worked out including the case of the mirror of the quartic in {\\mathbbm{P}^3}, where due to further algebraic constraints, the differential ring coincides with quasi modular forms.

Global Gauge Anomalies in Two-Dimensional Bosonic Sigma Models

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Gawȩdzki, Krzysztof; Suszek, Rafał R.; Waldorf, Konrad

2011-03-01

We revisit the gauging of rigid symmetries in two-dimensional bosonic sigma models with a Wess-Zumino term in the action. Such a term is related to a background closed 3-form H on the target space. More exactly, the sigma-model Feynman amplitudes of classical fields are associated to a bundle gerbe with connection of curvature H over the target space. Under conditions that were unraveled more than twenty years ago, the classical amplitudes may be coupled to the topologically trivial gauge fields of the symmetry group in a way which assures infinitesimal gauge invariance. We show that the resulting gauged Wess-Zumino amplitudes may, nevertheless, exhibit global gauge anomalies that we fully classify. The general results are illustrated on the example of the WZW and the coset models of conformal field theory. The latter are shown to be inconsistent in the presence of global anomalies. We introduce a notion of equivariant gerbes that allow an anomaly-free coupling of the Wess-Zumino amplitudes to all gauge fields, including the ones in non-trivial principal bundles. Obstructions to the existence of equivariant gerbes and their classification are discussed. The choice of different equivariant structures on the same bundle gerbe gives rise to a new type of discrete-torsion ambiguities in the gauged amplitudes. An explicit construction of gerbes equivariant with respect to the adjoint symmetries over compact simply connected simple Lie groups is given.

Six Sigma software development

CERN Document Server

Tayntor, Christine B

2002-01-01

Since Six Sigma has had marked success in improving quality in other settings, and since the quality of software remains poor, it seems a natural evolution to apply the concepts and tools of Six Sigma to system development and the IT department. Until now however, there were no books available that applied these concepts to the system development process. Six Sigma Software Development fills this void and illustrates how Six Sigma concepts can be applied to all aspects of the evolving system development process. It includes the traditional waterfall model and in the support of legacy systems,

Anomalies of hidden local chiral symmetries in sigma-models and extended supergravities

International Nuclear Information System (INIS)

Vecchia, P. di; Ferrara, S.; Girardello, L.

1985-01-01

Non-linear sigma-models with hidden gauge symmetries are anomalous, at the quantum level, when coupled to chiral fermions in not anomaly free representations of the hidden chiral symmetry. These considerations generally apply to supersymmetric kaehlerian sigma-models on coset spaces with hidden chiral symmetries as well as to extended supergravities in four dimensions with local SU(N) symmetry. The presence of the anomaly implies that the scenario of dynamical generation of gauge vector bosons has to be reconsidered in these theories. (orig.)

Ward Identity and Scattering Amplitudes for Nonlinear Sigma Models

Science.gov (United States)

Low, Ian; Yin, Zhewei

2018-02-01

We present a Ward identity for nonlinear sigma models using generalized nonlinear shift symmetries, without introducing current algebra or coset space. The Ward identity constrains correlation functions of the sigma model such that the Adler's zero is guaranteed for S -matrix elements, and gives rise to a subleading single soft theorem that is valid at the quantum level and to all orders in the Goldstone decay constant. For tree amplitudes, the Ward identity leads to a novel Berends-Giele recursion relation as well as an explicit form of the subleading single soft factor. Furthermore, interactions of the cubic biadjoint scalar theory associated with the single soft limit, which was previously discovered using the Cachazo-He-Yuan representation of tree amplitudes, can be seen to emerge from matrix elements of conserved currents corresponding to the generalized shift symmetry.

Sigma and opioid receptors in human brain tumors

International Nuclear Information System (INIS)

Thomas, G.E.; Szuecs, M.; Mamone, J.Y.; Bem, W.T.; Rush, M.D.; Johnson, F.E.; Coscia, C.J.

1990-01-01

Human brain tumors and nude mouse-borne human neuroblastomas and gliomas were analyzed for sigma and opioid receptor content. Sigma binding was assessed using [ 3 H] 1, 3-di-o-tolylguanidine (DTG), whereas opioid receptor subtypes were measured with tritiated forms of the following: μ, [D-ala 2 , mePhe 4 , gly-ol 5 ] enkephalin (DAMGE); κ, ethylketocyclazocine (EKC) or U69,593; δ, [D-pen 2 , D-pen 5 ] enkephalin (DPDPE) or [D-ala 2 , D-leu 5 ] enkephalin (DADLE) with μ suppressor present. Binding parameters were estimated by homologous displacement assays followed by analysis using the LIGAND program. Sigma binding was detected in 15 of 16 tumors examined with very high levels found in a brain metastasis from an adenocarcinoma of lung and a human neuroblastoma (SK-N-MC) passaged in nude mice. κ opioid receptor binding was detected in 4 of 4 glioblastoma multiforme specimens and 2 of 2 human astrocytoma cell lines tested but not in the other brain tumors analyzed

Running Head: Implementing Six Sigma Efforts

Science.gov (United States)

Lindsay, Jamie Eleaitia Mae

2005-01-01

Six Sigma is an organization wide program that provides common set of goals, language, and methodology for improving the overall quality of the processes within the organization (Davis & Heineke 2004). Six Sigma main concern is for the customer. What will the customers want? Need? Six Sigma has a model that helps Sigma get implemented DMAIC model…

In vitro and in vivo characterisation of [{sup 3}H]ANSTO-14 binding to the {sigma}{sub 1} binding sites

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Vu H. E-mail: V.H.Nguyen@ansto.gov.au; Mardon, Karine; Kassiou, Michael; Christie, MacDonald J

1999-02-01

ABSTRACT. N-(4-phenylbutyl)-3-hydroxy-4-azahexacyclo[5.4.1.0{sup 2,6}.0{sup 3,10}.0{sup 5,9}.0{sup 8}= {sup ,11}]dodecane (ANSTO-14) showed the highest activity for the {sigma}{sub 1} site ( K{sub i}=9.4 nM) and 19-fold {sigma}{sub 1}/{sigma}{sub 2} selectivity. The present study showed that [{sup 3}H]ANSTO-14 binds to a single high-affinity site in guinea pig brain membranes with an equilibrium K{sub d} of 8.0 {+-} 0.3 nM, in good agreement with the kinetic studies ( K{sub d}=13.3{+-}5.4 nM, n=4), and a B{sub max} of 3,199 {+-} 105 fmol/mg protein ( n=4). The in vivo biodistribution of [{sup 3}H]ANSTO-14 showed a high uptake in the diencephalon. Pretreatment of rats with {sigma} ligands including (+)-pentazocine ({sigma}{sub 1}), ANSTO-14 ({sigma}{sub 1}), and DTG ({sigma}{sub 1} and {sigma}{sub 2}) did not significantly reduce radiotracer uptake in the brain, but did in the spleen. A labelled metabolite was found in the liver and brain. Due to its insensitivity to {sigma} ligands, the accumulation of [{sup 3}H]ANSTO-14 in the brain indicates high nonspecific binding. Therefore, [{sup 3}H]ANSTO-14 is a suitable ligand for labelling {sigma}{sub 1} sites in vitro but is not suitable for brain imaging of {sigma} binding sites in vivo.

(4,0) supersymmetric sigma-model and t-duality

International Nuclear Information System (INIS)

Lhallabi, T.

1997-08-01

The conserved supercurrents J ++ and J -- are deduced for the (4,0) supersymmetric sigma model on harmonic superspace with arbitrary background gauge connection. These are introduced in the Lagrangian density of the model by their couplings to the analytic gauge superfields Γ -- and Γ ++ . The T-duality transformations are obtained by integrating out the analytic gauge superfields. Finally the (4,0) supersymmetric anomaly is derived. (author). 20 refs

On the 1/N expansion of the two-dimensional non-linear sigma-model: The vestige of chiral geometry

International Nuclear Information System (INIS)

Flume, R.

1978-11-01

We investigate the functioning of the O(N)-symmetry of the non-linear two-dimensional sigma-model using the 1/N expansion. The mechanism of O(N)-symmetry restoration is made explicit. We show that the O(N) invariant operators are in a one to one correspondance with the (c-number) invariants of the classical model. We observe a phenomenon, important in the context of the symmetry restoration, which might be called 'transmutation of anomalies'. That is, an anomaly of the equations of motion appearing before a summation of graphs contributing to the leading order of 1/N as a short distance effect becomes, after the summation, a long-distance effect. (orig.) [de

Non-linear sigma model on the fuzzy supersphere

International Nuclear Information System (INIS)

Kurkcuoglu, Seckin

2004-01-01

In this note we develop fuzzy versions of the supersymmetric non-linear sigma model on the supersphere S (2,2) . In hep-th/0212133 Bott projectors have been used to obtain the fuzzy C P 1 model. Our approach utilizes the use of supersymmetric extensions of these projectors. Here we obtain these (super)-projectors and quantize them in a fashion similar to the one given in hep-th/0212133. We discuss the interpretation of the resulting model as a finite dimensional matrix model. (author)

Baryons as solitonic solutions of the chiral sigma model

International Nuclear Information System (INIS)

Bentz, W.; Hartmann, J.; Beck, F.

1996-01-01

Self-consistent solitonic solutions with baryon number one are obtained in the chiral quark sigma model. The translational invariant vacuum is stabilized by a Landau ghost subtraction procedure based on the requirement of the Kaellacute en-Lehmann (KL) representation for the meson propagators. The connection of this ghost free model (KL model) to the more popular Nambu-Jona-Lasinio (NJL) model is discussed in detail. copyright 1996 The American Physical Society

Generalized complex geometry, generalized branes and the Hitchin sigma model

International Nuclear Information System (INIS)

Zucchini, Roberto

2005-01-01

Hitchin's generalized complex geometry has been shown to be relevant in compactifications of superstring theory with fluxes and is expected to lead to a deeper understanding of mirror symmetry. Gualtieri's notion of generalized complex submanifold seems to be a natural candidate for the description of branes in this context. Recently, we introduced a Batalin-Vilkovisky field theoretic realization of generalized complex geometry, the Hitchin sigma model, extending the well known Poisson sigma model. In this paper, exploiting Gualtieri's formalism, we incorporate branes into the model. A detailed study of the boundary conditions obeyed by the world sheet fields is provided. Finally, it is found that, when branes are present, the classical Batalin-Vilkovisky cohomology contains an extra sector that is related non trivially to a novel cohomology associated with the branes as generalized complex submanifolds. (author)

2D Poisson sigma models with gauged vectorial supersymmetry

Energy Technology Data Exchange (ETDEWEB)

Bonezzi, Roberto [Dipartimento di Fisica ed Astronomia, Università di Bologna and INFN, Sezione di Bologna,via Irnerio 46, I-40126 Bologna (Italy); Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile); Sundell, Per [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile); Torres-Gomez, Alexander [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile); Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile-UACh,Valdivia (Chile)

2015-08-12

In this note, we gauge the rigid vectorial supersymmetry of the two-dimensional Poisson sigma model presented in arXiv:1503.05625. We show that the consistency of the construction does not impose any further constraints on the differential Poisson algebra geometry than those required for the ungauged model. We conclude by proposing that the gauged model provides a first-quantized framework for higher spin gravity.

Euclidean supersymmetry, twisting and topological sigma models

International Nuclear Information System (INIS)

Hull, C.M.; Lindstroem, U.; Santos, L. Melo dos; Zabzine, M.; Unge, R. von

2008-01-01

We discuss two dimensional N-extended supersymmetry in Euclidean signature and its R-symmetry. For N = 2, the R-symmetry is SO(2) x SO(1, 1), so that only an A-twist is possible. To formulate a B-twist, or to construct Euclidean N = 2 models with H-flux so that the target geometry is generalised Kahler, it is necessary to work with a complexification of the sigma models. These issues are related to the obstructions to the existence of non-trivial twisted chiral superfields in Euclidean superspace.

Sv-map between type I and heterotic sigma models

Science.gov (United States)

Fan, Wei; Fotopoulos, A.; Stieberger, S.; Taylor, T. R.

2018-05-01

The scattering amplitudes of gauge bosons in heterotic and open superstring theories are related by the single-valued projection which yields heterotic amplitudes by selecting a subset of multiple zeta value coefficients in the α‧ (string tension parameter) expansion of open string amplitudes. In the present work, we argue that this relation holds also at the level of low-energy expansions (or individual Feynman diagrams) of the respective effective actions, by investigating the beta functions of two-dimensional sigma models describing world-sheets of open and heterotic strings. We analyze the sigma model Feynman diagrams generating identical effective action terms in both theories and show that the heterotic coefficients are given by the single-valued projection of the open ones. The single-valued projection appears as a result of summing over all radial orderings of heterotic vertices on the complex plane representing string world-sheet.

Naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein partially purified from rat liver and rat brain membranes: an opioid/sigma receptor?

Science.gov (United States)

Tsao, L I; Su, T P

1997-02-01

A naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein was partially purified from rat liver and rat brain membranes in an affinity chromatography originally designed to purify sigma receptors. Detergent-solubilized extracts from membranes were adsorbed to Sephadex G-25 resin containing an affinity ligand for sigma receptors: N-(2- 3,4-dichlorophenyl]ethyl)-N-(6-aminohexyl)-(2-[1-pyrrolidinyl]) ethylamine (DAPE). After eluting the resin with haloperidol, a protein that bound [3H](+)SKF-10047 was detected in the eluates. However, the protein was not the sigma receptor. [3H](+)SKF-10047 binding to the protein was inhibited by the following compounds in the order of decreasing potency: (+)pentazocine > (-) pentazocine > (+/-)cyclazocine > (-)morphine > (-)naloxone > haloperidol > (+)SKF-10047 > DADLE > (-)SKF-10047. Further, the prototypic sigma receptor ligands, such as 1,3-di-o-tolylguanidine (DTG), (+)3-PPP, and progesterone, bound poorly to the protein. Tryptic digestion and heat treatment of the affinity-purified protein abolished radioligand binding. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE) of the partially-purified protein from the liver revealed a major diffuse band with a molecular mass of 31 kDa, a polypeptide of 65 kDa, and another polypeptide of > 97 kDa. This study demonstrates the existence of a novel protein in the rat liver and rat brain which binds opioids, benzomorphans, and haloperidol with namomolar affinity. The protein resembles the opioid/sigma receptor originally proposed by Martin et al. [(1976): J. Pharmacol. Exp. Ther., 197:517-532.]. A high degree of purification of this protein has been achieved in the present study.

Sigma-delta modulator modeling analysis and design

International Nuclear Information System (INIS)

Ge Binjie; Wang Xin'an; Zhang Xing; Feng Xiaoxing; Wang Qingqin

2010-01-01

This paper introduces a new method for SC sigma-delta modulator modeling. It studies the integrator's different equivalent circuits in the integrating and sampling phases. This model uses the OP-AMP input pair's tail current (I 0 ) and overdrive voltage (v on ) as variables. The modulator's static and dynamic errors are analyzed. A group of optimized I 0 and v on for maximum SNR and power x area ratio can be obtained through this model. As examples, a MASH21 modulator for digital audio and a second order modulator for RFID baseband are implemented and tested, and they can achieve 91 dB and 72 dB respectively, which verifies the modeling and design criteria. (semiconductor integrated circuits)

Poisson sigma model with branes and hyperelliptic Riemann surfaces

International Nuclear Information System (INIS)

Ferrario, Andrea

2008-01-01

We derive the explicit form of the superpropagators in the presence of general boundary conditions (coisotropic branes) for the Poisson sigma model. This generalizes the results presented by Cattaneo and Felder [''A path integral approach to the Kontsevich quantization formula,'' Commun. Math. Phys. 212, 591 (2000)] and Cattaneo and Felder ['Coisotropic submanifolds in Poisson geometry and branes in the Poisson sigma model', Lett. Math. Phys. 69, 157 (2004)] for Kontsevich's angle function [Kontsevich, M., 'Deformation quantization of Poisson manifolds I', e-print arXiv:hep.th/0101170] used in the deformation quantization program of Poisson manifolds. The relevant superpropagators for n branes are defined as gauge fixed homotopy operators of a complex of differential forms on n sided polygons P n with particular ''alternating'' boundary conditions. In the presence of more than three branes we use first order Riemann theta functions with odd singular characteristics on the Jacobian variety of a hyperelliptic Riemann surface (canonical setting). In genus g the superpropagators present g zero mode contributions

Sigma and opioid receptors in human brain tumors

Energy Technology Data Exchange (ETDEWEB)

Thomas, G.E.; Szuecs, M.; Mamone, J.Y.; Bem, W.T.; Rush, M.D.; Johnson, F.E.; Coscia, C.J. (St. Louis Univ. School of Medicine, MO (USA))

1990-01-01

Human brain tumors and nude mouse-borne human neuroblastomas and gliomas were analyzed for sigma and opioid receptor content. Sigma binding was assessed using ({sup 3}H) 1, 3-di-o-tolylguanidine (DTG), whereas opioid receptor subtypes were measured with tritiated forms of the following: {mu}, (D-ala{sup 2}, mePhe{sup 4}, gly-ol{sup 5}) enkephalin (DAMGE); {kappa}, ethylketocyclazocine (EKC) or U69,593; {delta}, (D-pen{sup 2}, D-pen{sup 5}) enkephalin (DPDPE) or (D-ala{sup 2}, D-leu{sup 5}) enkephalin (DADLE) with {mu} suppressor present. Binding parameters were estimated by homologous displacement assays followed by analysis using the LIGAND program. Sigma binding was detected in 15 of 16 tumors examined with very high levels found in a brain metastasis from an adenocarcinoma of lung and a human neuroblastoma (SK-N-MC) passaged in nude mice. {kappa} opioid receptor binding was detected in 4 of 4 glioblastoma multiforme specimens and 2 of 2 human astrocytoma cell lines tested but not in the other brain tumors analyzed.

Excitation functions of pion reactions on 14N, 16O, and 19F through the (3,3) resonance

International Nuclear Information System (INIS)

Jacob, N.P. Jr.; Markowitz, S.S.

1976-01-01

Cross sections for pion-induced reactions of the form (π,πN) and more complex spallation reactions of the form (π,X) have been measured from 50--550 MeV on the target nuclei 14 N, 16 O, and 19 F using the secondary pion beams at the Lawrence Berkeley Laboratory 184-inch synchrocyclotron and the Clinton P. Anderson Meson Physics Facility. The dominance of the (3,3) free-particle resonance is seen in all excitation functions determined in this work. Relative to the 12 C(π/sup plus-or-minus/,πN) 11 C reactions, the (π/sup plus-or-minus/,πN) reactions on 14 N, 16 O, and 19 F have magnitudes of 0.2, 1, and 0.7, respectively. The cross section ratio R=sigma (π - ,π - n)/sigma (π + ,π N) =1.68+-0.18 for 14 N at 188+-15 MeV, 1.68+-0.05 for 16 O at 188+-9 MeV, and 1.68+-0.03 for 19 F at 178+-2 MeV incident pion energy. The results from this work are compared to previous pion work, analogous proton-induced reactions, Monte Carlo intranuclear cascade-evaporation calculations, and to a semiclassical nucleon charge-exchange model which convincingly explains the (π,πN) reaction mechanism in the (3,3) resonance region

String Sigma Models on Curved Supermanifolds

Directory of Open Access Journals (Sweden)

Roberto Catenacci

2018-04-01

Full Text Available We use the techniques of integral forms to analyze the easiest example of two-dimensional sigma models on a supermanifold. We write the action as an integral of a top integral form over a D = 2 supermanifold, and we show how to interpolate between different superspace actions. Then, we consider curved supermanifolds, and we show that the definitions used for flat supermanifolds can also be used for curved supermanifolds. We prove it by first considering the case of a curved rigid supermanifold and then the case of a generic curved supermanifold described by a single superfield E.

The Lie-Poisson structure of integrable classical non-linear sigma models

International Nuclear Information System (INIS)

Bordemann, M.; Forger, M.; Schaeper, U.; Laartz, J.

1993-01-01

The canonical structure of classical non-linear sigma models on Riemannian symmetric spaces, which constitute the most general class of classical non-linear sigma models known to be integrable, is shown to be governed by a fundamental Poisson bracket relation that fits into the r-s-matrix formalism for non-ultralocal integrable models first discussed by Maillet. The matrices r and s are computed explicitly and, being field dependent, satisfy fundamental Poisson bracket relations of their own, which can be expressed in terms of a new numerical matrix c. It is proposed that all these Poisson brackets taken together are representation conditions for a new kind of algebra which, for this class of models, replaces the classical Yang-Baxter algebra governing the canonical structure of ultralocal models. The Poisson brackets for the transition matrices are also computed, and the notorious regularization problem associated with the definition of the Poisson brackets for the monodromy matrices is discussed. (orig.)

Teoria das Restrições, Lean Manufacturing e Seis Sigma: limites e possibilidades de integração

Directory of Open Access Journals (Sweden)

Diego Augusto de Jesus Pacheco

2014-12-01

Full Text Available O principal objetivo deste estudo foi analisar os pontos de convergência e as divergências entre a Teoria das Restrições, o Lean Manufacturing e o Seis Sigma quando usados de maneira integrada para a melhoria contínua operacional de sistemas produtivos. O eixo principal de discussão desse estudo foi buscar identificar na literatura características de exclusão e similaridades entre as três abordagens quando aplicadas de maneira integrada em sistemas produtivos. Para conduzir essa pesquisa, fez-se uma ampla pesquisa bibliográfica, entre 1995 e 2011, nas principais bases de dados nacionais e internacionais, em busca do estado da arte sobre o tema. Os resultados desse estudo sugerem que Teoria das Restrições, Lean Manufacturing e Seis Sigma possuem diversos elementos complementares que se sobrepõem aos pontos divergentes e que há um vasto campo de pesquisa a ser explorado sobre o tema. Como resultado, o presente estudo apresenta a análise crítica comparativa de 28 critérios relevantes à compreensão das três abordagens assim como uma agenda de pesquisa sobre o tema identificada a partir das lacunas encontradas.

Unitary-model-operator approach to Λ17O and lambda-nucleon effective interaction

International Nuclear Information System (INIS)

Fujii, Shinichiro; Okamoto, Ryoji; Suzuki, Kenji

1998-01-01

The unitary-model-operator approach (UMOA) is applied to Λ 17 O. A lambda-nucleon effective interaction is derived, taking the coupling of the sigma-nucleon channel into account. The lambda single-particle energies are calculated for the Os 1/2 , Op 3/2 and Op 1/2 states employing the Nijmegen soft-core potential. (author)

Modeling of structural and thermodynamics properties of sigma-phase for the Fe-Cr system

Directory of Open Access Journals (Sweden)

Udovskya A.

2012-01-01

Full Text Available The three- sub-lattice model (3SLM for description of atom’s distribution of two components with different coordination numbers (12, 14 and 15, into s-phase structure depended on composition and temperature is depictured in this paper. Energetic parameters of 3SLM were calculated by fitting procedure fixed to results obtained by ab-initio calculations conducted for paramagnetic states of differently ordered complexes stayed at the sigma-phase’s crystal structure for Fe-Cr system at 0 K. Respective algorithm and computer program have allowed to calculate an atom distribution of components upon the sub-lattices of s-phase at 300 - 1100 K. There is satisfactory agreement between calculated results and the experimental data obtained by neutron and structural research methods. Obtained results demonstrate satisfactory agreement between calculated and experimental data of BCC solutions and sigma - phase of the Fe-Cr system stayed at an equilibrium state.

Nambu sigma model and effective membrane actions

Energy Technology Data Exchange (ETDEWEB)

Jurco, Branislav, E-mail: jurco@karlin.mff.cuni.cz [Mathematical Institute, Charles University, Prague 186 75 (Czech Republic); Schupp, Peter, E-mail: p.schupp@jacobs-university.de [Jacobs University Bremen, 28759 Bremen (Germany); Maxwell Institute for Mathematical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, Scotland (United Kingdom)

2012-07-09

We propose an effective action for a p{sup Prime }-brane with open p-branes ending on it. The action has dual descriptions similar to the commutative and non-commutative ones of the DBI action for D-branes and open strings. The Poisson structure governing the non-commutativity of the D-brane is replaced by a Nambu structure and the open-closed string relations are generalized to the case of p-branes utilizing a novel Nambu sigma model description of p-branes. In the case of an M5-brane our action interpolates between M5-actions already proposed in the literature and matrix-model like actions involving Nambu structures.

Nambu sigma model and effective membrane actions

International Nuclear Information System (INIS)

Jurčo, Branislav; Schupp, Peter

2012-01-01

We propose an effective action for a p ′ -brane with open p-branes ending on it. The action has dual descriptions similar to the commutative and non-commutative ones of the DBI action for D-branes and open strings. The Poisson structure governing the non-commutativity of the D-brane is replaced by a Nambu structure and the open-closed string relations are generalized to the case of p-branes utilizing a novel Nambu sigma model description of p-branes. In the case of an M5-brane our action interpolates between M5-actions already proposed in the literature and matrix-model like actions involving Nambu structures.

Universality for 1d Random Band Matrices: Sigma-Model Approximation

Science.gov (United States)

Shcherbina, Mariya; Shcherbina, Tatyana

2018-02-01

The paper continues the development of the rigorous supersymmetric transfer matrix approach to the random band matrices started in (J Stat Phys 164:1233-1260, 2016; Commun Math Phys 351:1009-1044, 2017). We consider random Hermitian block band matrices consisting of W× W random Gaussian blocks (parametrized by j,k \\in Λ =[1,n]^d\\cap Z^d ) with a fixed entry's variance J_{jk}=δ _{j,k}W^{-1}+β Δ _{j,k}W^{-2} , β >0 in each block. Taking the limit W→ ∞ with fixed n and β , we derive the sigma-model approximation of the second correlation function similar to Efetov's one. Then, considering the limit β , n→ ∞, we prove that in the dimension d=1 the behaviour of the sigma-model approximation in the bulk of the spectrum, as β ≫ n , is determined by the classical Wigner-Dyson statistics.

The SigmaR1 chaperone drives breast and colorectal cancer cell migration by tuning SK3-dependent Ca2+ homeostasis.

Science.gov (United States)

Gueguinou, M; Crottès, D; Chantôme, A; Rapetti-Mauss, R; Potier-Cartereau, M; Clarysse, L; Girault, A; Fourbon, Y; Jézéquel, P; Guérin-Charbonnel, C; Fromont, G; Martin, P; Pellissier, B; Schiappa, R; Chamorey, E; Mignen, O; Uguen, A; Borgese, F; Vandier, C; Soriani, O

2017-06-22

The remodeling of calcium homeostasis contributes to the cancer hallmarks and the molecular mechanisms involved in calcium channel regulation in tumors remain to be characterized. Here, we report that SigmaR1, a stress-activated chaperone, is required to increase calcium influx by triggering the coupling between SK3, a Ca 2+ -activated K + channel (KCNN3) and the voltage-independent calcium channel Orai1. We show that SigmaR1 physically binds SK3 in BC cells. Inhibition of SigmaR1 activity, either by molecular silencing or by the use of sigma ligand (igmesine), decreased SK3 current and Ca 2+ entry in breast cancer (BC) and colorectal cancer (CRC) cells. Interestingly, SigmaR1 inhibition diminished SK3 and/or Orai1 levels in lipid nanodomains isolated from BC cells. Analyses of tissue microarray from CRC patients showed higher SigmaR1 expression levels in cancer samples and a correlation with tumor grade. Moreover, the exploration of a cohort of 4937 BC patients indicated that high expression of SigmaR1 and Orai1 channels was significantly correlated to a lower overall survival. As the SK3/Orai1 tandem drives invasive process in CRC and bone metastasis progression in BC, our results may inaugurate innovative therapeutic approaches targeting SigmaR1 to control the remodeling of Ca 2+ homeostasis in epithelial cancers.

Off-shell dynamics of the O(3) NLS model beyond Monte Carlo and perturbation theory

International Nuclear Information System (INIS)

Balog, J.; Niedermaier, M.

1997-01-01

The off-shell dynamics of the O(3) non-linear sigma model is probed in terms of spectral densities and two-point functions by means of the form factor approach. The exact form factors of the spin field, Noether current, EM tensor and the topological charge density are computed up to six particles. The corresponding n≤6 particle spectral densities are used to compute the two-point functions, and are argued to deviate at most a few per mille from the exact answer in the entire energy range below 10 3 in units of the mass gap. To cover yet higher energies we propose an extrapolation scheme to arbitrary particle numbers based on a novel scaling hypothesis for the spectral densities. It yields candidate results for the exact two-point functions at all energy scales and allows us to exactly determine the values of two, previously unknown, non-perturbative constants. (orig.)

Sigma-delta modulator modeling analysis and design

Energy Technology Data Exchange (ETDEWEB)

Ge Binjie; Wang Xin' an; Zhang Xing; Feng Xiaoxing; Wang Qingqin, E-mail: wangxa@szpku.edu.c [Key Laboratory of Integrated Microsystem Science and Engineering Applications, Shenzhen Graduate School of Peking University, Shenzhen 518055 (China)

2010-09-15

This paper introduces a new method for SC sigma-delta modulator modeling. It studies the integrator's different equivalent circuits in the integrating and sampling phases. This model uses the OP-AMP input pair's tail current (I{sub 0}) and overdrive voltage (v{sub on}) as variables. The modulator's static and dynamic errors are analyzed. A group of optimized I{sub 0} and v{sub on} for maximum SNR and power x area ratio can be obtained through this model. As examples, a MASH21 modulator for digital audio and a second order modulator for RFID baseband are implemented and tested, and they can achieve 91 dB and 72 dB respectively, which verifies the modeling and design criteria. (semiconductor integrated circuits)

Orientifolds and D-branes in N=2 gauged linear sigma models

CERN Document Server

Brunner, Ilka

We study parity symmetries and boundary conditions in the framework of gauged linear sigma models. This allows us to investigate the Kaehler moduli dependence of the physics of D-branes as well as orientifolds in a Calabi-Yau compactification. We first determine the parity action on D-branes and define the set of orientifold-invariant D-branes in the linear sigma model. Using probe branes on top of orientifold planes, we derive a general formula for the type (SO vs Sp) of orientifold planes. As applications, we show how compactifications with and without vector structure arise naturally at different real slices of the Kaehler moduli space of a Calabi-Yau compactification. We observe that orientifold planes located at certain components of the fixed point locus can change type when navigating through the stringy regime.

Sigma-1 receptor agonists directly inhibit Nav1.2/1.4 channels.

Directory of Open Access Journals (Sweden)

Xiao-Fei Gao

Full Text Available (+-SKF 10047 (N-allyl-normetazocine is a prototypic and specific sigma-1 receptor agonist that has been used extensively to study the function of sigma-1 receptors. (+-SKF 10047 inhibits K(+, Na(+ and Ca2+ channels via sigma-1 receptor activation. We found that (+-SKF 10047 inhibited Na(V1.2 and Na(V1.4 channels independently of sigma-1 receptor activation. (+-SKF 10047 equally inhibited Na(V1.2/1.4 channel currents in HEK293T cells with abundant sigma-1 receptor expression and in COS-7 cells, which barely express sigma-1 receptors. The sigma-1 receptor antagonists BD 1063,BD 1047 and NE-100 did not block the inhibitory effects of (+-SKF-10047. Blocking of the PKA, PKC and G-protein pathways did not affect (+-SKF 10047 inhibition of Na(V1.2 channel currents. The sigma-1 receptor agonists Dextromethorphan (DM and 1,3-di-o-tolyl-guanidine (DTG also inhibited Na(V1.2 currents through a sigma-1 receptor-independent pathway. The (+-SKF 10047 inhibition of Na(V1.2 currents was use- and frequency-dependent. Point mutations demonstrated the importance of Phe(1764 and Tyr(1771 in the IV-segment 6 domain of the Na(V1.2 channel and Phe(1579 in the Na(V1.4 channel for (+-SKF 10047 inhibition. In conclusion, our results suggest that sigma-1 receptor agonists directly inhibit Na(V1.2/1.4 channels and that these interactions should be given special attention for future sigma-1 receptor function studies.

Nonabelian Gauged Linear Sigma Model

Institute of Scientific and Technical Information of China (English)

Yongbin RUAN

2017-01-01

The gauged linear sigma model (GLSM for short) is a 2d quantum field theory introduced by Witten twenty years ago.Since then,it has been investigated extensively in physics by Hori and others.Recently,an algebro-geometric theory (for both abelian and nonabelian GLSMs) was developed by the author and his collaborators so that he can start to rigorously compute its invariants and check against physical predications.The abelian GLSM was relatively better understood and is the focus of current mathematical investigation.In this article,the author would like to look over the horizon and consider the nonabelian GLSM.The nonabelian case possesses some new features unavailable to the abelian GLSM.To aid the future mathematical development,the author surveys some of the key problems inspired by physics in the nonabelian GLSM.

The low-energy constants of the extended linear sigma model

Energy Technology Data Exchange (ETDEWEB)

Divotgey, Florian; Giacosa, Francesco; Kovacs, Peter; Rischke, Dirk H. [Institut fuer Theoretische Physik, Goethe-Universitaet Frankfurt am Main (Germany)

2016-07-01

The low-energy dynamics of Quantum Chromodynamics (QCD) is fully determined by the interactions of the (pseudo-) Nambu-Goldstone bosons of spontaneous chiral symmetry breaking, i.e., for two quark flavors, the pions. Pion dynamics is described by the low-energy effective theory of QCD, chiral perturbation theory (ChPT), which is based on the nonlinear realization of chiral symmetry. An alternative description is provided by the Linear Sigma Model, where chiral symmetry is linearly realized. An extended version of this model, the so-called extended Linear Sigma Model (eLSM) was recently developed which incorporates all J{sup P}=0{sup ±}, 1{sup ±} anti qq mesons up to 2 GeV in mass. A fit of the coupling constants of this model to experimentally measured masses and decay widths has a surprisingly good quality. In this talk, it is demonstrated that the low-energy limit of the eLSM, obtained by integrating out all fields which are heavier than the pions, assumes the same form as ChPT. Moreover, the low-energy constants (LECs) of the eLSM agree with those of ChPT.

Geometry of surfaces associated to Grassmannian sigma models

International Nuclear Information System (INIS)

Delisle, L; Hussin, V; Zakrzewski, W J

2015-01-01

We investigate the geometric characteristics of constant Gaussian curvature surfaces obtained from solutions of the G(m, n) sigma model. Most of these solutions are related to the Veronese sequence. We show that we can distinguish surfaces with the same Gaussian curvature using additional quantities like the topological charge and the mean curvature. The cases of G(1,n) = CP n-1 and G(2,n) are used to illustrate these characteristics. (paper)

Mucosal vaccination by adenoviruses displaying reovirus sigma 1

Energy Technology Data Exchange (ETDEWEB)

Weaver, Eric A. [Department of Internal Medicine, Division of Infectious Diseases, Translational Immunovirology and Biodefense Program, Mayo Clinic, Rochester, MN 55902 (United States); Camacho, Zenaido T. [Department of Cell Biology, Department of Natural Sciences, Western New Mexico University, Silver City, NM 88062 (United States); Hillestad, Matthew L. [Nephrology Training Program, Mayo Clinic, Rochester, MN 55902 (United States); Crosby, Catherine M.; Turner, Mallory A.; Guenzel, Adam J.; Fadel, Hind J. [Virology and Gene Therapy Graduate Program, Mayo Clinic, Rochester, MN 55902 (United States); Mercier, George T. [Department of Physics, University of Houston, Houston, TX 77004 (United States); Barry, Michael A., E-mail: mab@mayo.edu [Department of Internal Medicine, Division of Infectious Diseases, Translational Immunovirology and Biodefense Program, Mayo Clinic, Rochester, MN 55902 (United States); Department of Immunology and Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55902 (United States)

2015-08-15

We developed adenovirus serotype 5 (Ad5) vectors displaying the sigma 1 protein from reovirus as mucosal vaccines. Ad5-sigma retargets to JAM-1 and sialic acid, but has 40-fold reduced gene delivery when compared to Ad5. While weaker at transduction, Ad5-sigma generates stronger T cell responses than Ad5 when used for mucosal immunization. In this work, new Ad5-fiber-sigma vectors were generated by varying the number of fiber β-spiral shaft repeats (R) between the fiber tail and sigma. Increasing chimera length led to decreasing insertion of these proteinsAd5 virions. Ad-R3 and R14 vectors effectively targeted JAM-1 in vitro while R20 did not. When wereused to immunize mice by the intranasal route, Ad5-R3-sigma produced higher serum and vaginal antibody responses than Ad5. These data suggest optimized Ad-sigma vectors may be useful vectors for mucosal vaccination. - Highlights: • Constructed adenoviruses (Ads) displaying different reovirus sigma 1 fusion proteins. • Progressively longer chimeras were more poorly encapsidated onto Ad virions. • Ad5-R3-sigma mediated better systemic and mucosal immune responses than Ad5.

Mucosal vaccination by adenoviruses displaying reovirus sigma 1

International Nuclear Information System (INIS)

Weaver, Eric A.; Camacho, Zenaido T.; Hillestad, Matthew L.; Crosby, Catherine M.; Turner, Mallory A.; Guenzel, Adam J.; Fadel, Hind J.; Mercier, George T.; Barry, Michael A.

2015-01-01

We developed adenovirus serotype 5 (Ad5) vectors displaying the sigma 1 protein from reovirus as mucosal vaccines. Ad5-sigma retargets to JAM-1 and sialic acid, but has 40-fold reduced gene delivery when compared to Ad5. While weaker at transduction, Ad5-sigma generates stronger T cell responses than Ad5 when used for mucosal immunization. In this work, new Ad5-fiber-sigma vectors were generated by varying the number of fiber β-spiral shaft repeats (R) between the fiber tail and sigma. Increasing chimera length led to decreasing insertion of these proteinsAd5 virions. Ad-R3 and R14 vectors effectively targeted JAM-1 in vitro while R20 did not. When wereused to immunize mice by the intranasal route, Ad5-R3-sigma produced higher serum and vaginal antibody responses than Ad5. These data suggest optimized Ad-sigma vectors may be useful vectors for mucosal vaccination. - Highlights: • Constructed adenoviruses (Ads) displaying different reovirus sigma 1 fusion proteins. • Progressively longer chimeras were more poorly encapsidated onto Ad virions. • Ad5-R3-sigma mediated better systemic and mucosal immune responses than Ad5

Development of a system dynamics model based on Six Sigma methodology

Directory of Open Access Journals (Sweden)

José Jovani Cardiel Ortega

2017-01-01

Full Text Available A dynamic model to analyze the complexity associated with the manufacturing systems and to improve the performance of the process through the Six Sigma philosophy is proposed. The research focuses on the implementation of the system dynamics tool to comply with each of the phases of the DMAIC methodology. In the first phase, define, the problem is articulated, collecting data, selecting the variables, and representing them in a mental map that helps build the dynamic hypothesis. In the second phase, measure, model is formulated, equations are developed, and Forrester diagram is developed to carry out the simulation. In the third phase, analyze, the simulation results are studied. For the fourth phase, improving, the model is validated through a sensitivity analysis. Finally, in control phase, operation policies are proposed. This paper presents the development of a dynamic model of the system of knitted textile production knitted developed; the implementation was done in a textile company in southern Guanajuato. The results show an improvement in the process performance by increasing the level of sigma allowing the validation of the proposed approach.

Usulan Perbaikan Kualitas Penggulungan Benang Nilon Dengan Menggunakan Metode Six Sigma di PT. XYZ

Directory of Open Access Journals (Sweden)

I Wayan Sukania

2016-07-01

Full Text Available Abstrak: PT. XYZ merupakan perusahaan yang bergerak dibidang textil yang memproduksi benang jahit. Perusahaan selalu berusaha meningkatkan kualitas produknya dalam penanganan produk yang cacat yang terjadi pada proses produksi karena jumlah cacat yang timbul cukup banyak. Untuk itu perlu dilakukan tindakan perbaikan dalam menurunkan tingkat cacat yang terjadi. Pada penelitian ini, penulis menggunakan metode six sigma dengan model perbaikian Define-Measure-Analyze-Improve-Control (DMAIC dan Failure Mode and Effect Analysis (FMEA untuk menganalisis kinerja proses dan produk yang dihasilkan. Penerapan metode tersebut diharapakan mampu meningkatkan kualitas perusahaan yang sekarang pada level sigma 3,8 menuju tingkat kinerja kualitas 6 Sigma. Kata kunci: Six Sigma, FMEA Abstract: PT. XYZ is a company engaged in textile-producing sewing thread. The company is always trying to improve the quality of products due to quite a lot of products defects occur in the production process. It is necessary for corrective action in reducing the level of defects that occur. In this research, the six sigma with Define-Measure Analyze-Improve-Control (DMAIC and Failure Mode and Effect Analysis (FMEA models were used to analyze the performance of processes and products. Application of those methods are expected to be able to improve the quality of company that are now at the level of sigma 3,8 to 6 sigma level of quality performance . Keywords: Six Sigma, FMEA

6 sigma quality performance

International Nuclear Information System (INIS)

Yu, Yeong Hak

2000-03-01

This deals with 6 sigma quality performance introducing company which has 6 sigma quality management, 6 sigma quality activity and customer, secret of success of 6 sigma quality management, what 6 sigma is, 6 sigma quality management propel system 5 propel steps of project like point of 6 sigma, flow of problem solution, tool for propel of project, performance of CTQ and total customer satisfaction, and quality management system and 6 sigma quality.

Adoção do Programa Seis Sigma em um Fornecedor Automotivo: Análise de Fatores Relevantes na Implementação

Directory of Open Access Journals (Sweden)

Miguel, Paulo Augusto Cauchick

2012-12-01

Full Text Available Since the development of the Six Sigma concept by Motorola in the 80’s many changes have made the market more competitive and demanding, especially in the automotive sector. The present work aims to describe the results of a case study of the Six Sigma program in an automotive company in the state of São Paulo. This paper seeks to identify characteristics about the use of Six Sigma, such as implementation tools, project selection, training and the results obtained with the projects. In the end, besides identifying if the critical factors to the success of the program that the theory presents match with the reality of the company. As the main conclusion, the study shows that the company has used many of the theory recommendations in its application. Concerning training, the efforts were higher than the literature recommends, and it may be one of the main reasons for the success of the program.

Quantitative application of sigma metrics in medical biochemistry.

Science.gov (United States)

Nanda, Sunil Kumar; Ray, Lopamudra

2013-12-01

Laboratory errors are result of a poorly designed quality system in the laboratory. Six Sigma is an error reduction methodology that has been successfully applied at Motorola and General Electric. Sigma (σ) is the mathematical symbol for standard deviation (SD). Sigma methodology can be applied wherever an outcome of a process has to be measured. A poor outcome is counted as an error or defect. This is quantified as defects per million (DPM). A six sigma process is one in which 99.999666% of the products manufactured are statistically expected to be free of defects. Six sigma concentrates, on regulating a process to 6 SDs, represents 3.4 DPM (defects per million) opportunities. It can be inferred that as sigma increases, the consistency and steadiness of the test improves, thereby reducing the operating costs. We aimed to gauge performance of our laboratory parameters by sigma metrics. Evaluation of sigma metrics in interpretation of parameter performance in clinical biochemistry. The six month internal QC (October 2012 to march 2013) and EQAS (external quality assurance scheme) were extracted for the parameters-Glucose, Urea, Creatinine, Total Bilirubin, Total Protein, Albumin, Uric acid, Total Cholesterol, Triglycerides, Chloride, SGOT, SGPT and ALP. Coefficient of variance (CV) were calculated from internal QC for these parameters. Percentage bias for these parameters was calculated from the EQAS. Total allowable errors were followed as per Clinical Laboratory Improvement Amendments (CLIA) guidelines. Sigma metrics were calculated from CV, percentage bias and total allowable error for the above mentioned parameters. For parameters - Total bilirubin, uric acid, SGOT, SGPT and ALP, the sigma values were found to be more than 6. For parameters - glucose, Creatinine, triglycerides, urea, the sigma values were found to be between 3 to 6. For parameters - total protein, albumin, cholesterol and chloride, the sigma values were found to be less than 3. ALP was the best

Topological sigma B model in 4-dimensions

International Nuclear Information System (INIS)

Jun, Hyun-Keun; Park, Jae-Suk

2008-01-01

We propose a 4-dimensional version of topological sigma B-model, governing maps from a smooth compact 4-manifold M to a Calabi-Yau target manifold X. The theory depends on complex structure of X, while is independent of Kaehler metric of X. The theory is also a 4-dimensional topological field theory in the sense that the theory is independent of variation of Riemannian metric of the source 4-manifold M, potentially leading to new smooth invariant of 4-manifolds. We argue that the theory also comes with a topological family parametrized by the extended moduli space of complex structures.

Mutations in type 3 reovirus that determine binding to sialic acid are contained in the fibrous tail domain of viral attachment protein sigma1.

Science.gov (United States)

Chappell, J D; Gunn, V L; Wetzel, J D; Baer, G S; Dermody, T S

1997-03-01

The reovirus attachment protein, sigma1, determines numerous aspects of reovirus-induced disease, including viral virulence, pathways of spread, and tropism for certain types of cells in the central nervous system. The sigma1 protein projects from the virion surface and consists of two distinct morphologic domains, a virion-distal globular domain known as the head and an elongated fibrous domain, termed the tail, which is anchored into the virion capsid. To better understand structure-function relationships of sigma1 protein, we conducted experiments to identify sequences in sigma1 important for viral binding to sialic acid, a component of the receptor for type 3 reovirus. Three serotype 3 reovirus strains incapable of binding sialylated receptors were adapted to growth in murine erythroleukemia (MEL) cells, in which sialic acid is essential for reovirus infectivity. MEL-adapted (MA) mutant viruses isolated by serial passage in MEL cells acquired the capacity to bind sialic acid-containing receptors and demonstrated a dependence on sialic acid for infection of MEL cells. Analysis of reassortant viruses isolated from crosses of an MA mutant virus and a reovirus strain that does not bind sialic acid indicated that the sigma1 protein is solely responsible for efficient growth of MA mutant viruses in MEL cells. The deduced sigma1 amino acid sequences of the MA mutant viruses revealed that each strain contains a substitution within a short region of sequence in the sigma1 tail predicted to form beta-sheet. These studies identify specific sequences that determine the capacity of reovirus to bind sialylated receptors and suggest a location for a sialic acid-binding domain. Furthermore, the results support a model in which type 3 sigma1 protein contains discrete receptor binding domains, one in the head and another in the tail that binds sialic acid.

Superstring sigma models from spin chains: the SU(1,1 vertical bar 1) case

International Nuclear Information System (INIS)

Bellucci, S.; Casteill, P.-Y.; Morales, J.F.

2005-01-01

We derive the coherent state representation of the integrable spin chain Hamiltonian with non-compact supersymmetry group G=SU(1,1 vertical bar 1). By passing to the continuous limit, we find a spin chain sigma model describing a string moving on the supercoset G/H, H being the stabilizer group. The action is written in a manifestly G-invariant form in terms of the Cartan forms and the string coordinates in the supercoset. The spin chain sigma model is shown to agree with that following from the Green-Schwarz action describing two-charged string spinning on AdS 5 xS 5

T^{\\sigma}_{\\rho}(G) Theories and Their Hilbert Series

CERN Document Server

Cremonesi, Stefano; Mekareeya, Noppadol; Zaffaroni, Alberto

2015-01-01

We give an explicit formula for the Higgs and Coulomb branch Hilbert series for the class of 3d N=4 superconformal gauge theories T^{\\sigma}_{\\rho}(G) corresponding to a set of D3 branes ending on NS5 and D5-branes, with or without O3 planes. Here G is a classical group, \\sigma is a partition of G and \\rho a partition of the dual group G^\\vee. In deriving such a formula we make use of the recently discovered formula for the Hilbert series of the quantum Coulomb branch of N=4 superconformal theories. The result can be expressed in terms of a generalization of a class of symmetric functions, the Hall-Littlewood polynomials, and can be interpreted in mathematical language in terms of localization. We mainly consider the case G=SU(N) but some interesting results are also given for orthogonal and symplectic groups.

Thermodynamic modeling of La2O3-SrO-Mn2O3-Cr2O3 for solid oxide fuel cell applications

DEFF Research Database (Denmark)

Povoden-Karadeniz, E.; Chen, Ming; Ivas, Toni

2012-01-01

The thermodynamic La–Sr–Mn–Cr–O oxide database is obtained as an extension of thermodynamic descriptions of oxide subsystems using the calculation of phase diagrams approach. Concepts of the thermodynamic modeling of solid oxide phases are discussed. Gibbs energy functions of SrCrO4, Sr2.67Cr2O8......, Sr2CrO4, and SrCr2O4 are presented, and thermodynamic model parameters of La–Sr–Mn–Chromite perovskite are given. Experimental solid solubilities and nonstoichiometries in La1xSrxCrO3d and LaMn1xCrxO3d are reproduced by the model. The presented oxide database can be used for applied computational...... thermodynamics of traditional lanthanum manganite cathode with Cr-impurities. It represents the fundament for extensions to higher orders, aiming on thermodynamic calculations in noble symmetric solid oxide fuel cells...

Does the {sigma}(1580)((3)/(2)){sup -} resonance exist?

Energy Technology Data Exchange (ETDEWEB)

Olmsted, J.; Prakhov, S.; Manley, D.M.; Allgower, C.E.; Bekrenev, V.S.; Briscoe, W.J.; Clajus, M.; Comfort, J.R.; Craig, K.; Grosnick, D.; Isenhower, D.; Knecht, N.; Koetke, D.D.; Kozlenko, N.G.; Kruglov, S.; Kulbardis, A.A.; Lolos, G.; Lopatin, I.V.; Manweiler, R.; Marusic, A.; McDonald, S.; Nefkens, B.M.K.; Papandreou, Z.; Peaslee, D.C.; Phaisangittisakul, N.; Price, J.W.; Ramirez, A.F.; Sadler, M.; Shafi, A.; Spinka, H.; Stanislaus, T.D.S.; Starostin, A.; Staudenmaier, H.M.; Strakovsky, I.I.; Supek, I.; Tippens, W.B

2004-05-20

Precise new data for the reaction K{sup -}p{yields}{pi}{sup 0}{lambda} are presented in the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new light on claims for the {sigma}(1580)((3)/(2)){sup -} resonance, which (if it exists with the specified quantum numbers) must be an exotic baryon because of its very low mass. Our results show no evidence for this state.

[Reducing patient waiting time for the outpatient phlebotomy service using six sigma].

Science.gov (United States)

Kim, Yu Kyung; Song, Kyung Eun; Lee, Won Kil

2009-04-01

One of the challenging issues of the outpatient phlebotomy services at most hospitals is that patients have a long wait. The outpatient phlebotomy team of Kyungpook National University Hospital applied six sigma breakthrough methodologies to reduce the patient waiting time. The DMAIC (Define, Measure, Analyze, Improve, and Control) model was employed to approach the project. Two hundred patients visiting the outpatient phlebotomy section were asked to answer the questionnaires at inception of the study to ascertain root causes. After correction, we surveyed 285 patients for same questionnaires again to follow-up the effects. A defect was defined as extending patient waiting time so long and at the beginning of the project, the performance level was 2.61 sigma. Using fishbone diagram, all the possible reasons for extending patient waiting time were captured, and among them, 16 causes were proven to be statistically significant. Improvement plans including a new receptionist, automatic specimen transport system, and adding one phlebotomist were put into practice. As a result, the number of patients waited more than 5 min significantly decreased, and the performance level reached 3.0 sigma in December 2007 and finally 3.35 sigma in July 2008. Applying the six sigma, the performance level of waiting times for blood drawing exceeding five minutes were improved from 2.61 sigma to 3.35 sigma.

Phase-Field Modeling of Sigma-Phase Precipitation in 25Cr7Ni4Mo Duplex Stainless Steel

Science.gov (United States)

Malik, Amer; Odqvist, Joakim; Höglund, Lars; Hertzman, Staffan; Ågren, John

2017-10-01

Phase-field modeling is used to simulate the formation of sigma phase in a model alloy mimicking a commercial super duplex stainless steel (SDSS) alloy, in order to study precipitation and growth of sigma phase under linear continuous cooling. The so-called Warren-Boettinger-McFadden (WBM) model is used to build the basis of the multiphase and multicomponent phase-field model. The thermodynamic inconsistency at the multiple junctions associated with the multiphase formulation of the WBM model is resolved by means of a numerical Cut-off algorithm. To make realistic simulations, all the kinetic and the thermodynamic quantities are derived from the CALPHAD databases at each numerical time step, using Thermo-Calc and TQ-Interface. The credibility of the phase-field model is verified by comparing the results from the phase-field simulations with the corresponding DICTRA simulations and also with the empirical data. 2D phase-field simulations are performed for three different cooling rates in two different initial microstructures. A simple model for the nucleation of sigma phase is also implemented in the first case. Simulation results show that the precipitation of sigma phase is characterized by the accumulation of Cr and Mo at the austenite-ferrite and the ferrite-ferrite boundaries. Moreover, it is observed that a slow cooling rate promotes the growth of sigma phase, while a higher cooling rate restricts it, eventually preserving the duplex structure in the SDSS alloy. Results from the phase-field simulations are also compared quantitatively with the experiments, performed on a commercial 2507 SDSS alloy. It is found that overall, the predicted morphological features of the transformation and the composition profiles show good conformity with the empirical data.

Masses and sigma terms of doubly charmed baryons up to O (p4) in manifestly Lorentz-invariant baryon chiral perturbation theory

Science.gov (United States)

Yao, De-Liang

2018-02-01

We calculate the masses and sigma terms of the doubly charmed baryons up to next-to-next-to-next-to-leading order [i.e., O (p4) ] in a covariant baryon chiral perturbation theory by using the extended-on-mass-shell renormalization scheme. Their expressions both in infinite and finite volumes are provided for chiral extrapolation in lattice QCD. As a first application, our chiral results of the masses are confronted with the existing lattice QCD data in the presence of finite-volume corrections. Up to O (p3) , all relevant low-energy constants can be well determined. As a consequence, we obtain the physical values for the masses of Ξc c and Ωc c baryons by extrapolating to the physical limit. Our determination of the Ξc c mass is consistent with the recent experimental value by LHCb Collaboration, however, larger than the one by SELEX Collaboration. In addition, we predict the pion-baryon and strangeness-baryon sigma terms, as well as the mass splitting between the Ξc c and Ωc c states. Their quark mass dependences are also discussed. The numerical procedure can be applied to the chiral results of O (p4) order, where more unknown constants are involved, when more data are available for unphysical pion masses.

Applying a Hybrid MCDM Model for Six Sigma Project Selection

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Fu-Kwun Wang

2014-01-01

Full Text Available Six Sigma is a project-driven methodology; the projects that provide the maximum financial benefits and other impacts to the organization must be prioritized. Project selection (PS is a type of multiple criteria decision making (MCDM problem. In this study, we present a hybrid MCDM model combining the decision-making trial and evaluation laboratory (DEMATEL technique, analytic network process (ANP, and the VIKOR method to evaluate and improve Six Sigma projects for reducing performance gaps in each criterion and dimension. We consider the film printing industry of Taiwan as an empirical case. The results show that our study not only can use the best project selection, but can also be used to analyze the gaps between existing performance values and aspiration levels for improving the gaps in each dimension and criterion based on the influential network relation map.

Transport property of novel sono-catalysed LiCF sub 3 SO sub 3 doped SiO sub 2 -PEG ormolyte

CERN Document Server

Jung, H Y; Wi, C J; Whang, C M

2003-01-01

Transport property of a novel sono-catalysed LiCF sub 3 SO sub 3 doped SiO sub 2 -10 wt% PEG ormolyte is reported. The ormolyte was synthesized by sol-gel method by varying the LiCF sub 3 SO sub 3 concentration [Li/O] from 0 to 0.1 in mole. The composition with [Li/O] = 0.05 exhibited the highest conductivity (sigma sub 2 sub 5 sub d eg sub C = 2.4x10 sup - sup 4 S cm sup - sup 1) with an enhancement of 10 sup 3 from that of the host matrix: SiO sub 2 -10 wt% PEG sono gel and has been referred to as 'optimum conducting composition (OCC)'. The direct determination of Li sup + ion mobility (mu)/mobile ion concentration (n) indicated that the enhancement was due to the increase in mu and n both. The temperature dependence of sigma, mu and n were carried out for the OCC samples in order to evaluate the respective energies involved in different thermally activated processes and to understand the ion transport mechanism. The ion transference number (t sub i sub o sub n) measurement inferred the ions as the sole cha...

Development of a Mathematical Model for Multivariate Process by Balanced Six Sigma

Directory of Open Access Journals (Sweden)

Díaz-Castellanos Elizabeth Eugenia

2015-07-01

Full Text Available The Six Sigma methodology is widely used in business to improve quality, increase productivity and lower costs, impacting on business improvement. However, today the challenge is to use those tools for improvements that will have a direct impact on the differentiation of value, which requires the alignment of Six Sigma with the competitive strategies of the organization.Hence the importance of a strategic management system to measure, analyze, improve and control corporate performance, while setting out responsibilities of leadership and commitment. The specific purpose of this research is to provide a mathematical model through the alignment of strategic objectives (Balanced Scorecard and tools for productivity improvement (Six Sigma for processes with multiple answers, which is sufficiently robust so that it can serve as basis for application in manufacturing and thus effectively link strategy performance and customer satisfaction. Specifically we worked with a case study: Córdoba, Ver. The model proposes that is the strategy, performance and customer satisfaction are aligned, the organization will benefit from the intense relationship between process performance and strategic initiatives. These changes can be measured by productivity and process metrics such as cycle time, production rates, production efficiency and percentage of reprocessing, among others.

Expression and Prognostic Significance of 14-3-3sigma and ERM Family Protein Expression in Periampullary Neoplasms

NARCIS (Netherlands)

Hustinx, Steven R.; Fukushima, Noriyoshi; Zahurak, Marianna L.; Riall, Taylor Sohn; Maitra, Anirban; Brosens, Lodewijk; Cameron, John L.; Yeo, Charles J.; Offerhaus, G. Johan A.; Hruban, Ralph H.; Goggins, Michael

2005-01-01

Aberrant gene expression in pancreatic ductal adenocarcinomas contributes to the dismal outcome of patients who develop this disease. The 5' region of 14-3-3sigma (stratifin) is hypomethylated in pancreatic adenocarcinomas and is associated with gene overexpression. In multiple experimental systems,

Comparative Analysis between Lean, Six Sigma and Lean Six Sigma Concepts

OpenAIRE

Alexandra Mirela Cristina MUNTEANU

2017-01-01

This paper analyzes the benefits of Lean Six Sigma in comparison with Lean and Six Sigma, traditional improvement methodologies. The introduction highlights the appearance of Lean Six Sigma, early 2000s, as well as the benefits brought by the integrated approach. The following parts of the study emphasize the main differences between methodologies and their commonalities based on their synergy. Finally the advantages of Lean Six Sigma versus Lean and Six Sigma are analyzed and systematized by...

Non-renormalizability of supersymmetric non-linear sigma models in four dimensions

International Nuclear Information System (INIS)

Spence, B.

1985-01-01

The one-loop, on-shell, ultraviolet-divergent part of the effective action is calculated for the N=1 and 2 supersymmetric non-linear sigma models in four dimensions. These infinities cannot be absorbed into a redefinition of the bare Kaehler potential and the theories are not renormalizable. (orig.)

Electromagnetic axial anomaly in a generalized linear sigma model

Science.gov (United States)

Fariborz, Amir H.; Jora, Renata

2017-06-01

We construct the electromagnetic anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four-quark content. We compute in the leading order of this framework the decays into two photons of six pseudoscalars: π0(137 ), π0(1300 ), η (547 ), η (958 ), η (1295 ) and η (1760 ). Our results agree well with the available experimental data.

Genetic parameters estimates for gestation length in beef cattle Componentes de variância para o período de gestação em bovinos de corte

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J.C.M.C. Rocha

2005-12-01

Full Text Available Variance components were estimated for gestation length fitting the additive direct effect of calf, maternal genetic effect and sire effect as random effects. The statistical models also included the fixed effects of contemporary group, that included the date of breeding (AI, date of birth, and sex of calf, and the covariate age of dam at calving (linear and quadratic. Two different models were used, model 1 considering GL as a trait of the calf, and model 2 considering GL as a trait of the dam. The means of gestation length for the purebred animals were 294.55 days (males and 293.34 days (females, while for the crossbred animals they were 292.49 days (males and 292.55 days (females. Variance components for the purebred animals, fitting model 1, were 14.47, 72.78 and 57.31, for the additive genetic (sigma2a, total phenotypic (sigma2p and residual (sigma2e effects, respectively, with a heritability estimate of 0.21. For the crossbred animals, variance components for sigma2a, sigma2p, sigma2e were 90.40, 127.35 and 36.95, respectively, with a heritability of 0.71. Fitting model 2, the estimated variance components for the purebred animals were 12.78, 5.01, 74.84 and 57.05 for sigma2a , sire of calf (sigma ²asire, sigma2p, and sigma2e , respectively. The sire effect accounted for 0.07 (c² of the phenotypic variance and the coefficient of repeatability was 0.17. For the crossbred animals, the variance components were 22.11 (sigma2a , 22.97 (sigma ²asire , 127.70 (sigma2p and 82.61 (sigma2e, while c² was 0.18 and repeatability was 0.17. Therefore, regarding selection of beef cattle, it is suggested to use the heritability estimate obtained by model 1, where GL is considered as a trait of the calf.Estimaram-se os componentes de variância do período de gestação (PG considerando-se o efeito direto do bezerro e os efeitos direto da vaca e aleatório do touro (pai do bezerro. Além dos efeitos aleatórios, os modelos estatísticos incluíram os

Comparative Analysis between Lean, Six Sigma and Lean Six Sigma Concepts

Directory of Open Access Journals (Sweden)

Alexandra Mirela Cristina MUNTEANU

2017-06-01

Full Text Available This paper analyzes the benefits of Lean Six Sigma in comparison with Lean and Six Sigma, traditional improvement methodologies. The introduction highlights the appearance of Lean Six Sigma, early 2000s, as well as the benefits brought by the integrated approach. The following parts of the study emphasize the main differences between methodologies and their commonalities based on their synergy. Finally the advantages of Lean Six Sigma versus Lean and Six Sigma are analyzed and systematized by author in order to reveal Lean Six Sigma’s benefits.

Production quality improvement analysis of grey cambric using Six Sigma Method

Directory of Open Access Journals (Sweden)

Shafira Yosa Permata

2018-01-01

Full Text Available Quality has an important role in business. A good quality means it is able to meet the required standards. The concept of quality must be comprehensive, whether the quality of the product or its process. PT Textile Yogyakarta is still having a high rate of defect products. The Waste Assessment Model (WAM was used to identify the wastes that frequently occur by scoring each type of waste. The results show the waste rank are defect 26.12%, inventory 20.36%, motion 15.26%, transportation 14.51%, over production 12.91%, waiting 7.17%, and process 3.67%. While using the Six Sigma from the 4 CTQ process, the result of sigma level is 3.3. It means that the sigma level of PT Textile Yogyakarta is still under the average sigma level in Japan which is 5 Sigma. As for the improvement part, FMEA AHP was used and the results show that the first rank is the uncleaned woof residue, the second rank is the uncut thread which has an RPN value of 8.04 that was caused when the operator did not clean the machine from the woof residue, and the third rank is the malfunctioned machine which has an RPN value of 7.32 that was caused by broken kleting.

Evidence for the decay sigma+ --> pmu+ mu-.

Science.gov (United States)

Park, H K; Burnstein, R A; Chakravorty, A; Chen, Y C; Choong, W S; Clark, K; Dukes, E C; Durandet, C; Felix, J; Fu, Y; Gidal, G; Gustafson, H R; Holmstrom, T; Huang, M; James, C; Jenkins, C M; Jones, T; Kaplan, D M; Lederman, L M; Leros, N; Longo, M J; Lopez, F; Lu, L C; Luebke, W; Luk, K B; Nelson, K S; Perroud, J-P; Rajaram, D; Rubin, H A; Volk, J; White, C G; White, S L; Zyla, P

2005-01-21

We report the first evidence for the decay Sigma(+)-->pmu(+)mu(-) from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(Sigma(+)-->pmu(+)mu(-))=[8.6(+6.6)(-5.4)(stat)+/-5.5(syst)]x10(-8). The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma(+)-->pP(0),P0-->mu(+)mu(-) with a P0 mass of 214.3+/-0.5 MeV/c(2) and branching ratio B(Sigma(+)-->pP(0),P0-->mu(+)mu(-))=[3.1(+2.4)(-1.9)(stat)+/-1.5(syst)]x10(-8).

Seis Sigma: Fatores Críticos de Sucesso para sua Implantação

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Antonio Cesar Amaru Maximiano

2009-10-01

Full Text Available This article describes an investigation of critical success factors to implement Six Sigma in organizations operating in the Brazilian market place. Besides that, a secondary objective was to investigate the relationship between aspects like success perception among those companies which implemented Six Sigma, company size, company nationality, time of Six Sigma of implementation, continuous training, communication level between professionals, full-time and part-time Black Belts, project completion, project duration and project savings. Data were collected through an Internet questionnaire, distributed by email and sent to discussion groups involving Six Sigma professionals. Questionnaire development included a literature review and interviews with experienced Six Sigma professionals. The results indicated eight critical success factors for Six Sigma implementation: (a Leadership, (b Projects, (c Training, (d Communication and Review, (e Managerial Process, (f Black Belts Profile, (g Project Teams and (h Previous Quality Initiatives.

Dynamical generation of gauge bosons of hidden local symmetries in nonlinear sigma models

International Nuclear Information System (INIS)

Koegerler, R.; Lucha, W.; Neufeld, H.; Stremnitzer, H.

1988-01-01

We demonstrate how quantum corrections generate a kinetic term for the (at tree-level non-propagating) gauge fields of hidden local symmetries in nonlinear sigma models in four space-time dimensions. (orig.)

Structural influence of aluminium, gallium and indium metal oxides by means of dielectric and spectroscopic properties of CaO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system

Energy Technology Data Exchange (ETDEWEB)

Srinivasa Reddy, M. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India); Naga Raju, G. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India); Nagarjuna, G. [Department of Chemistry, Acharya Nagarjuna University, Nagarjunanagar, AP (India); Veeraiah, N. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India)]. E-mail: nvr8@rediffmail.com

2007-07-12

Dielectric constant ({epsilon}'), loss (tan {delta}), ac conductivity ({sigma}) of CaO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3}:M{sub 2}O{sub 3} (Al{sub 2}O{sub 3}, Ga{sub 2}O{sub 3} and In{sub 2}O{sub 3}) glasses with varying concentrations of M{sub 2}O{sub 3} (0-5 mol%), were measured as a function of frequency and temperature over moderately wide ranges. The analysis of results of these studies along with IR, Raman and optical absorption spectra and also DTA studies indicated that in the concentration ranges, 0 {<=} Al{sub 2}O{sub 3} {<=} 4, 0 {<=} Ga{sub 2}O{sub 3} {<=} 2 and 1 {<=} In{sub 2}O{sub 3} {<=} 5, Al{sup 3+}, Ga{sup 3+} ions occupy tetrahedral positions whereas In{sup 3+} ions take up octahedral substitutional positions, cross-link with the other structural units in the glass network and increase the rigidity of the glass network.

2D sigma models and differential Poisson algebras

International Nuclear Information System (INIS)

Arias, Cesar; Boulanger, Nicolas; Sundell, Per; Torres-Gomez, Alexander

2015-01-01

We construct a two-dimensional topological sigma model whose target space is endowed with a Poisson algebra for differential forms. The model consists of an equal number of bosonic and fermionic fields of worldsheet form degrees zero and one. The action is built using exterior products and derivatives, without any reference to a worldsheet metric, and is of the covariant Hamiltonian form. The equations of motion define a universally Cartan integrable system. In addition to gauge symmetries, the model has one rigid nilpotent supersymmetry corresponding to the target space de Rham operator. The rigid and local symmetries of the action, respectively, are equivalent to the Poisson bracket being compatible with the de Rham operator and obeying graded Jacobi identities. We propose that perturbative quantization of the model yields a covariantized differential star product algebra of Kontsevich type. We comment on the resemblance to the topological A model.

The clinicopathological and prognostic impact of 14-3-3 sigma expression on vulvar squamous cell carcinomas

OpenAIRE

Wang, Zhihui; Tropè, Claes G; Suo, Zhenhe; Trøen, Gunhild; Yang, Guanrui; Nesland, Jahn M; Holm, Ruth

2008-01-01

Background 14-3-3 sigma (σ) promotes G2/M cell cycle arrest by sequestering cyclin B1-CDC2 complex in cytoplasm. Down-regulation of 14-3-3σ, which has been demonstrated in various carcinomas, may contribute to malignant transformation. However, the exact role of 14-3-3σ in the pathogenesis of vulvar carcinoma is not fully characterized, and the prognostic impact of 14-3-3σ protein expression is still unknown. Methods ...

Stabilization of He2(A(sup 3)Sigma(sub u)(+)) molecules in liquid helium by optical pumping for vacuum UV laser

Science.gov (United States)

Zmuidzinas, J. S. (Inventor)

1978-01-01

A technique is disclosed for achieving large populations of metastable spin-aligned He2(a 3 Sigma u +) molecules in superfluid helium to obtain lasing in the vacuum ultraviolet wavelength regime around 0.0800 micron m by electronically exciting liquid (superfluid) helium with a comparatively low-current electron beam and spin aligning the metastable molecules by means of optical pumping with a modestly-powered (100mW) circularly-polarized continuous wave laser operating at, for example, 0.9096 or 0.4650 micron m. Once a high concentration of spin-aligned He2 (a 3 Sigma u +) is achieved with lifetimes of a few milliseconds, a strong microwave signal destroys the spin alignment and induces a quick collisional transition of He2 (a 3 Sigma u +) molecules to the a 1 Sigma u + state and thereby a lasing transition to the X 1 Sigma g + state.

Inference of sigma factor controlled networks by using numerical modeling applied to microarray time series data of the germinating prokaryote.

Science.gov (United States)

Strakova, Eva; Zikova, Alice; Vohradsky, Jiri

2014-01-01

A computational model of gene expression was applied to a novel test set of microarray time series measurements to reveal regulatory interactions between transcriptional regulators represented by 45 sigma factors and the genes expressed during germination of a prokaryote Streptomyces coelicolor. Using microarrays, the first 5.5 h of the process was recorded in 13 time points, which provided a database of gene expression time series on genome-wide scale. The computational modeling of the kinetic relations between the sigma factors, individual genes and genes clustered according to the similarity of their expression kinetics identified kinetically plausible sigma factor-controlled networks. Using genome sequence annotations, functional groups of genes that were predominantly controlled by specific sigma factors were identified. Using external binding data complementing the modeling approach, specific genes involved in the control of the studied process were identified and their function suggested.

Walls of massive K\\"ahler sigma models on SO(2N)/U(N) and Sp(N)/U(N)

OpenAIRE

Arai, Masato; Shin, Sunyoung

2011-01-01

We study the Bogomol'nyi-Prasad-Sommerfield wall solutions in massive K\\"ahler nonlinear sigma models on SO(2N)/U(N) and Sp(N)/U(N) in three-dimensional spacetime. We show that SO(2N)/U(N) and Sp(N)/U(N) models have 2^{N-1} and 2^N discrete vacua, respectively. We explicitly construct the exact BPS multiwall solutions for N\\le 3.

Study of the quasi-two body processes including {sigma}(1385) production in {pi}{sup -}p and K{sup -} reactions at 4 GeV/c; Estudio de procesos cuasi-dos cuerpos con produccion de {sigma} (1385) en interacciones {pi}{sup -}p y K{sup p} A 4 GeV/c

Energy Technology Data Exchange (ETDEWEB)

Aguilar-Benitez, M; Salicio, J

1981-07-01

An analysis of (1385) production in reactions of the type 0{sup +} 1/z 4 +{yields}>-1{sup +} 3+/2 and 0{sup -} + 1/2+{yields} 0{sup -} + 3*/2 is presented. A determination of the {sigma}(1385) production parameters Is performed and the results are compared with the predictions from several models. A transversity amplitudes reconstruction describing the processes {pi} {sup p} ->K(890) {sigma}(1385) and K{sup -}p {yields} 3{yields}{phi}(1385), {zeta}{sup -}{sigma}(1385) is obtained in a model independent way. We observe dominance of unnatural partly exchange in the production mechanisms. Exchanges of exotic quantum numbers are established by the study of {pi}p {yields} K{sup 0}+ {sigma}(1385)s and K{sup -} p{yields}>{pi}+{sigma}(1385){+-} processes. Additive quark model predictions are reasonable agreement with the experimental data. (Author)

Nonlinear sigma-models and their gauging in and out of superspace

International Nuclear Information System (INIS)

Hull, C.M.; California Univ., Santa Barbara; Karlhede, A.; Lindstroem, U.; Rocek, M.

1986-01-01

We analyze and generalize bosonic nonlinear sigma-models and their N=1,2 supersymmetric extensions in (4 spacetime-dimensional) N=1 superspace. We give a general construction of nonminimal kinetic terms for gauge fields and of N=1,2 gauging of isometries on Kaehler and hyper-Kaehler manifolds. In particular, we study the gauging of noncompact groups. We derive the complete component action and supertrace formula. For N=2 models, the supertrace always vanishes. (orig.)

Beta functions and central charge of supersymmetric sigma models with torsion

International Nuclear Information System (INIS)

Guadagnini, E.; Mintchev, M.

1987-01-01

We present a method for the computation of the renormalization group β-functions and the central charge in two-dimensional supersymmetric sigma models in a gravitational background. The two-loops results are exhibited. We use the Pauli-Villars regularization which preserves supersymmetry and permits an unambiguous treatment of the model with torsion. The central charge we derive for a general manifold is in agreement with the expression found on group manifolds. (orig.)

On the structure on non-local conservation laws in the two-dimensional non-linear sigma-model

International Nuclear Information System (INIS)

Zamolodchikov, Al.B.

1978-01-01

The non-local conserved charges are supposed to satisfy a special multiplicative law in the space of asymptotic states of the non-linear sigma-model. This supposition leads to factorization equations for two-particle scattering matrix elements and determines to some extent the action of these charges in the asymptotic space. Their conservation turns out to be consistent with the factorized S-matrix of the non-linear sigma-model. It is shown also that the factorized sine-Gordon S-matrix is consistent with a similar family of conservation laws

Marginal deformations of heterotic G 2 sigma models

Science.gov (United States)

Fiset, Marc-Antoine; Quigley, Callum; Svanes, Eirik Eik

2018-02-01

Recently, the infinitesimal moduli space of heterotic G 2 compactifications was described in supergravity and related to the cohomology of a target space differential. In this paper we identify the marginal deformations of the corresponding heterotic nonlinear sigma model with cohomology classes of a worldsheet BRST operator. This BRST operator is nilpotent if and only if the target space geometry satisfies the heterotic supersymmetry conditions. We relate this to the supergravity approach by showing that the corresponding cohomologies are indeed isomorphic. We work at tree-level in α' perturbation theory and study general geometries, in particular with non-vanishing torsion.

Superfield Lax formalism of supersymmetric sigma model on symmetric spaces

International Nuclear Information System (INIS)

Saleem, U.; Hassan, M.

2006-01-01

We present a superfield Lax formalism of the superspace sigma model based on the target space G/H and show that a one-parameter family of flat superfield connections exists if the target space G/H is a symmetric space. The formalism has been related to the existence of an infinite family of local and non-local superfield conserved quantities. A few examples have been given to illustrate the results. (orig.)

On the chiral phase transition in the linear sigma model

International Nuclear Information System (INIS)

Tran Huu Phat; Nguyen Tuan Anh; Le Viet Hoa

2003-01-01

The Cornwall- Jackiw-Tomboulis (CJT) effective action for composite operators at finite temperature is used to investigate the chiral phase transition within the framework of the linear sigma model as the low-energy effective model of quantum chromodynamics (QCD). A new renormalization prescription for the CJT effective action in the Hartree-Fock (HF) approximation is proposed. A numerical study, which incorporates both thermal and quantum effect, shows that in this approximation the phase transition is of first order. However, taking into account the higher-loop diagrams contribution the order of phase transition is unchanged. (author)

Torsion-induced gauge superfield mass generation for gauge-invariant non-linear. sigma. -models

Energy Technology Data Exchange (ETDEWEB)

Helayel-Neto, J.A. (Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro Universidade Catolica de Petropolis, RJ (Brazil)); Mokhtari, S. (International Centre for Theoretical Physics, Trieste (Italy)); Smith, A.W. (Universidade Catolica de Petropolis, RJ (Brazil))

1989-12-21

It is shown that the explicit breaking of (1,0)-supersymmetry by means of a torsion-like term yields dynamical mass generation for the gauge superfields which couple to a (1,0)-supersymmetric non-linear {sigma}-model. (orig.).

The gauge-invariant N=2 supersymmetric sigma-model with general scalar potential

International Nuclear Information System (INIS)

Sierra, G.; Townsend, P.K.

1984-01-01

We construct the supersymmetric sigma-model, in six dimensions, for an arbitrary hyper-Kaehler manifold, and its minimal coupling to super-Yang-Mills theory. Non-trivial reduction to five or four dimensions yields the corresponding five- or four-dimensional N=2 supersymmetric model with general scalar potential. We discuss briefly the coupling to supergravity in six dimensions and we give the on-shell supergravity torsion constraints. (orig.)

SIGMA without effort

International Nuclear Information System (INIS)

Hagedorn, R.; Reinfelds, J.

1978-01-01

SIGMA (System for Interactive Graphical Analysis) is an interactive computing language with automatic array handling and graphical facilities. It is designed as a tool for mathematical problem solving. The SIGMA language is simple, almost obvious, yet flexible and powerful. This tutorial introduces the beginner to SIGMA. It is supposed to be used at a graphics terminal having access to SIGMA. The user will learn the language in dialogue with the system in sixteen sessions of about one hour. The first session enables him already to compute and display functions of one or two variables. (Auth.)

Conformally parametrized surfaces associated with CPN-1 sigma models

International Nuclear Information System (INIS)

Grundland, A M; Hereman, W A; Yurdusen, I-dot

2008-01-01

Two-dimensional parametrized surfaces immersed in the su(N) algebra are investigated. The focus is on surfaces parametrized by solutions of the equations for the CP N-1 sigma model. The Lie-point symmetries of the CP N-1 model are computed for arbitrary N. The Weierstrass formula for immersion is determined and an explicit formula for a moving frame on a surface is constructed. This allows us to determine the structural equations and geometrical properties of surfaces in R N 2 -1 . The fundamental forms, Gaussian and mean curvatures, Willmore functional and topological charge of surfaces are given explicitly in terms of any holomorphic solution of the CP 2 model. The approach is illustrated through several examples, including surfaces immersed in low-dimensional su(N) algebras

Bound state solution of the Grassmannian nonlinear sigma model with fermions

International Nuclear Information System (INIS)

Abdalla, E.; Lima-Santos, A.

1987-11-01

We construct the s matrix for bound state (gauge-invariant) scattering for nonlinear sigma models defined on the manifold SU(N)/S(U(p)x (lower casex)U(n-p)) with fermions. It is not possible to compute gauge non-singlet matrix elements. In the present language they are not submitted to sufficiently many constraints derived from higher conservation laws. (author) [pt

Heterogeneous binding of sigma radioligands in the rat brain and liver

International Nuclear Information System (INIS)

Ross, S.B.

1991-01-01

The binding of four sigma receptor ligands, 3 H-(+)-N-allyl-N-normetazocine ( 3 H-(+)-SKF 10,047), 3 H-(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ( 3 H-(+)-3-PPP), 3 H-haloperidol and 3 H-N,N'-di(o-totyl)guanidine ( 3 H-DTG), and the cytochrome P450IID6 ligand and dopamine uptake inhibitor 3 H-1-[2-(diphenylmethoxy)ethyl]-4-(3-phenylpropyl)piperazine ( 3 H-GBR 12935) to membranal preparations of rat liver or whole rat brain was examined regarding kinetical properties and inhibition by various compounds with affinity for sigma binding sites or cytochrome P-450. In rat brain the density of binding sites was increased in order (+)-SKF 10,047 3 H-(+)-SKF 10,047 there were quite marked differences between the ligands studied. Multiple binding sites were also indicated by the low Hill coefficients found for most of the compounds studied. It was found that the cytochrome P-450 inhibitor proadifen (SKF 525A), like haloperidol, was a potent inhibitor of the binding of 3 H-(+)-SKF 10,047, 3 H-(+)-3-PPP and 3 H-haloperidol to the liver and brain preparations, less active in inhibiting the binding of 3 H-DTG and least effective on the binding of 3 H-GBR 12935. Another cytochrome P-450 inhibitor, L-lobeline, was particularly potent in inhibiting the binding of 3 H-DTG but was also quite potent inhibitor of the binding of the other sigma ligands. It was less potent in inhibiting the binding of 3 H-GBR 12935. The binding of the latter ligand was potently inhibited by the analogous compound GBR 12909 but of the other compounds examined only L-lobeline, proadifen, haloperidol, DTG and (+)-3-PPP had IC50 values below 10 μM. The possibility that the sigma binding sites are identical with some subforms of cytochrome P-450 is discussed. (author)

Análise da utilização de técnicas e ferramentas no programa Seis Sigma a partir de um levantamento tipo survey Analysis on the usage of techniques and tools from the Six-Sigma program on a survey-type assessment

Directory of Open Access Journals (Sweden)

Eduardo Guilherme Satolo

2009-01-01

Full Text Available O programa Seis Sigma é uma iniciativa adotada atualmente por muitas empresas e seu uso ocorre por meio de um processo altamente disciplinado e orientado, no qual são aplicadas diversas técnicas e ferramentas, que objetivam a geração de um ciclo de melhoria contínua. Diante desse fato e considerando a relevância do assunto, foi conduzido um levantamento tipo survey com o intuito de identificar e analisar as técnicas e ferramentas usadas nas etapas do método DMAIC e a sua comparação com a prescrição da literatura. Buscou-se levantar as técnicas e ferramentas mais e menos empregadas pelas empresas, permitindo-se confrontar estes resultados com outros levantamentos já realizados no exterior. Cabe destacar também que os resultados confirmaram o indicado pela literatura, os quais apontam que o programa Seis Sigma necessita apoiar-se em dados mensuráveis e confiáveis, evidenciando assim que o emprego das técnicas e ferramentas é indispensável junto ao método de melhoria DMAIC.The Six-Sigma program is an approach currently adopted by many companies and its usage occurs through a highly disciplined and guided process, in which several techniques and tools are applied, trYing to generate a continuous improvement cycle. Facing this fact and considering the relevance of the subject, a survey-based research was carried out. One of the objectives was to identify and analyse the techniques and tools used in the phases of the DMAIC and their comparison with the literature. The results consisted in assessing the techniques and tools most and least used by the companies, enabling to confront those with other previous research. It is also worthy highlighting that these results confirmed the indications of other publications, which state that the Six Sigma programme needs to be supported by measurable and trustworthy data. This makes evident that the usage of techniques and tools is indispensable for the DMAIC improvement method.

A healthcare Lean Six Sigma System for postanesthesia care unit workflow improvement.

Science.gov (United States)

Kuo, Alex Mu-Hsing; Borycki, Elizabeth; Kushniruk, Andre; Lee, Te-Shu

2011-01-01

The aim of this article is to propose a new model called Healthcare Lean Six Sigma System that integrates Lean and Six Sigma methodologies to improve workflow in a postanesthesia care unit. The methodology of the proposed model is fully described. A postanesthesia care unit case study is also used to demonstrate the benefits of using the Healthcare Lean Six Sigma System model by combining Lean and Six Sigma methodologies together. The new model bridges the service gaps between health care providers and patients, balances the requirements of health care managers, and delivers health care services to patients by taking the benefits of the Lean speed and Six Sigma high-quality principles. The full benefits of the new model will be realized when applied at both strategic and operational levels. For further research, we will examine how the proposed model is used in different real-world case studies.

Sigma A recognition sites in the Bacillus subtilis genome

DEFF Research Database (Denmark)

Jarmer, Hanne Østergaard; Larsen, Thomas Schou; Krogh, Anders Stærmose

2001-01-01

A hidden Markov model of sigma (A) RNA polymerase cofactor recognition sites in Bacillus subtilis, containing either the common or the extended -10 motifs, has been constructed based on experimentally verified sigma (A) recognition sites. This work suggests that more information exists...... at the initiation site of transcription in both types of promoters than previously thought. When tested on the entire B. subtilis genome, the model predicts that approximately half of the sigma (A) recognition sites are of the extended type. Some of the response-regulator aspartate phosphatases were among...

Lean Six Sigma implementation and organizational culture.

Science.gov (United States)

Knapp, Susan

2015-01-01

The purpose of this paper is to examine the relationship between four organizational cultural types defined by the Competing Values Framework and three Lean Six Sigma implementation components - management involvement, use of Lean Six Sigma methods and Lean Six Sigma infrastructure. The study involved surveying 446 human resource and quality managers from 223 hospitals located in Maine, New Hampshire, Vermont, Massachusetts and Rhode Island using the Organizational Culture Assessment Instrument. Findings - In total, 104 completed responses were received and analyzed using multivariate analysis of variance. Follow-up analysis of variances showed management support was significant, F(3, 100)=4.89, p cultures having significant interactions with management support. The relationship between organizational culture and Lean Six Sigma in hospitals provides information on how specific cultural characteristics impact the Lean Six Sigma initiative key components. This information assists hospital staff who are considering implementing quality initiatives by providing an understanding of what cultural values correspond to effective Lean Six Sigma implementation. Managers understanding the quality initiative cultural underpinnings, are attentive to the culture-shared values and norm's influence can utilize strategies to better implement Lean Six Sigma.

The sigma model on complex projective superspaces

Energy Technology Data Exchange (ETDEWEB)

Candu, Constantin; Mitev, Vladimir; Schomerus, Volker [DESY, Hamburg (Germany). Theory Group; Quella, Thomas [Amsterdam Univ. (Netherlands). Inst. for Theoretical Physics; Saleur, Hubert [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Physique Theorique; USC, Los Angeles, CA (United States). Physics Dept.

2009-08-15

The sigma model on projective superspaces CP{sup S-1} {sup vertical} {sup stroke} {sup S} gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle {theta}. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we propose a spin chain regularization of the CP{sup S-1} {sup vertical} {sup stroke} {sup S} model with open boundary conditions and use it to determine the spectrum at the conformal fixed point. The numerical results are in remarkable agreement with the continuum analysis. (orig.)

The sigma model on complex projective superspaces

International Nuclear Information System (INIS)

Candu, Constantin; Mitev, Vladimir; Schomerus, Volker; Quella, Thomas; Saleur, Hubert; USC, Los Angeles, CA

2009-08-01

The sigma model on projective superspaces CP S-1 vertical stroke S gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle θ. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we propose a spin chain regularization of the CP S-1 vertical stroke S model with open boundary conditions and use it to determine the spectrum at the conformal fixed point. The numerical results are in remarkable agreement with the continuum analysis. (orig.)

Application of Six Sigma Model to Evaluate the Analytical Quality of Four HbA1c Analyzers.

Science.gov (United States)

Maesa, Jos Eacute M; Fern Aacute Ndez-Riejos, Patricia; S Aacute Nchez-Mora, Catalina; Toro-Crespo, Mar Iacute A De; Gonz Aacute Lez-Rodriguez, Concepci Oacute N

2017-01-01

The Six Sigma Model is a global quality management system applicable to the determination of glycated hemoglobin (HbA1c). In addition, this model can ensure the three characteristics influencing the patient risk: the correct performance of the analytical method with low inaccuracy and bias, the quality control strategy used by the laboratory, and the necessary quality of the analyte. The aim of this study is to use the Six Sigma Model for evaluating quality criteria in the determination of glycated hemoglobin HbA1c and its application to assess four different HbA1c analyzers. Four HbA1c analyzers were evaluated: HA-8180V®, D-100®, G8®, and Variant II Turbo®. For 20 consecutive days, two levels of quality control (high and low) provided by the manufacturers were measured in each of the instruments. Imprecision (CV), bias, and Sigma values (σ) were calculated with the data obtained and a method decision chart was developed considering a range of quality requirements (allowable total error, TEa). For a TEa = 3%, HA-8180V = 1.54 σ, D-100 = 1.63 σ, G8 = 2.20 σ, and Variant II Turbo = -0.08 σ. For a TEa = 4%, HA-8180V = 2.34 σ, D-100 = 2.32 σ, G8 = 3.74 σ, and Variant II Turbo = 0.16 σ. For a TEa = 10%, HA8180V = 7.12 σ, D-100 = 6.46 σ, G8 = 13.0 σ, and Variant II Turbo = 1.56 σ. Applying the Stockholm consensus and its subsequent Milan review to the results: the maximum level in quality requirements for HbA1c is an allowable total error (TEa) = 3%, G8 is located in region 2 σ (2.20), which is a poor result, and HA-8180V and D-100 are both in region 1 σ (1.54 and 1.63, respectively), which is an unacceptable analytical performance.

Reactions of sigma-bonded organochromium(III)complexes

International Nuclear Information System (INIS)

Leslie, J.P. II.

1975-12-01

Three projects were carried out, each dealing with the kinetics and mechanism of reactions of sigma-bonded organochromium(III) complexes of the form (H 2 O) 5 CrR 2+ . Part I describes the kinetics of the reaction of dichloromethylchromium(III) ion with chromium(II) ion in aqueous acid. Part II deals with the radioexchange of 4-pyridinomethylchromium(III) ion with 51 Cr 2+ and the kinetics of formation of the organochromium species at 55 0 in 1 M H + . Part III deals with the reactions of Hg 2+ and CH 3 Hg + with a series of (H 2 O) 5 CrR 2+ complexes, in which R is an aliphatic alkyl group, a haloalkyl group, or an aralkyl group

Kinks, chains, and loop groups in the CPn sigma models

International Nuclear Information System (INIS)

Harland, Derek

2009-01-01

We consider topological solitons in the CP n sigma models in two space dimensions. In particular, we study 'kinks', which are independent of one coordinate up to a rotation of the target space, and 'chains', which are periodic in one coordinate up to a rotation of the target space. Kinks and chains both exhibit constituents, similar to monopoles and calorons in SU(n) Yang-Mills-Higgs and Yang-Mills theories. We examine the constituent structure using Lie algebras.

All (4,1): Sigma models with (4,q) off-shell supersymmetry

Energy Technology Data Exchange (ETDEWEB)

Hull, Chris [The Blackett Laboratory, Imperial College London,Prince Consort Road London SW7 @AZ (United Kingdom); Lindström, Ulf [The Blackett Laboratory, Imperial College London,Prince Consort Road London SW7 @AZ (United Kingdom); Department of Physics and Astronomy, Division of Theoretical Physics,Uppsala University, Box 516, SE-751 20 Uppsala (Sweden)

2017-03-08

Off-shell (4,q) supermultiplets in 2-dimensions are constructed for q=1,2,4. These are used to construct sigma models whose target spaces are hyperkähler with torsion. The off-shell supersymmetry implies the three complex structures are simultaneously integrable and allows us to construct actions using extended superspace and projective superspace, giving an explicit construction of the target space geometries.

Sigma Terms and Strangeness Contents of Baryon Octet in Modified Chiral Perturbation Theory

Institute of Scientific and Technical Information of China (English)

LI Xiao-Ya; L(U) Xiao-Fu

2006-01-01

In the frame work of chiral perturbation theory, a modified effective Lagrangian for meson-baryon system is constructed, where the SU(3) breaking effect for meson is considered. The difference between physical and chiral limit decay constants is taken into account. Calculated to one loop at O(p3), the sigma terms and strangeness contents of baryon octet are obtained.

BTZ black hole from Poisson–Lie T-dualizable sigma models with spectators

Directory of Open Access Journals (Sweden)

A. Eghbali

2017-09-01

Full Text Available The non-Abelian T-dualization of the BTZ black hole is discussed in detail by using the Poisson–Lie T-duality in the presence of spectators. We explicitly construct a dual pair of sigma models related by Poisson–Lie symmetry. The original model is built on a 2+1-dimensional manifold M≈O×G, where G as a two-dimensional real non-Abelian Lie group acts freely on M, while O is the orbit of G in M. The findings of our study show that the original model indeed is canonically equivalent to the SL(2,R Wess–Zumino–Witten (WZW model for a given value of the background parameters. Moreover, by a convenient coordinate transformation we show that this model describes a string propagating in a spacetime with the BTZ black hole metric in such a way that a new family of the solutions to low energy string theory with the BTZ black hole vacuum metric, constant dilaton field and a new torsion potential is found. The dual model is built on a 2+1-dimensional target manifold M˜ with two-dimensional real Abelian Lie group G˜ acting freely on it. We further show that the dual model yields a three-dimensional charged black string for which the mass M and axion charge Q per unit length are calculated. After that, the structure and asymptotic nature of the dual space–time including the horizon and singularity are determined.

Long-Term Haloperidol Treatment Prolongs QT Interval and Increases Expression of Sigma 1 and IP3 Receptors in Guinea Pig Hearts.

Science.gov (United States)

Stracina, Tibor; Slaninova, Iva; Polanska, Hana; Axmanova, Martina; Olejnickova, Veronika; Konecny, Petr; Masarik, Michal; Krizanova, Olga; Novakova, Marie

2015-07-01

Haloperidol is a neuroleptic drug used for a medication of various psychoses and deliria. Its administration is frequently accompanied by cardiovascular side effects, expressed as QT interval prolongation and occurrence of even lethal arrhythmias. Despite these side effects, haloperidol is still prescribed in Europe in clinical practice. Haloperidol binds to sigma receptors that are coupled with inositol 1,4,5-trisphosphate (IP3) receptors. Sigma receptors are expressed in various tissues, including heart muscle, and they modulate potassium channels. Together with IP3 receptors, sigma receptors are also involved in calcium handling in various tissues. Therefore, the present work aimed to study the effects of long-term haloperidol administration on the cardiac function. Haloperidol (2 mg/kg once a day) or vehiculum was administered by intraperitoneal injection to guinea pigs for 21 consecutive days. We measured the responsiveness of the hearts isolated from the haloperidol-treated animals to additional application of haloperidol. Expression of the sigma 1 receptor and IP3 receptors was studied by real time-PCR and immunohistochemical analyses. Haloperidol treatment caused the significant decrease in the relative heart rate and the prolongation of QT interval of the isolated hearts from the haloperidol-treated animals, compared to the hearts isolated from control animals. The expression of sigma 1 and IP3 type 1 and type 2 receptors was increased in both atria of the haloperidol-treated animals but not in ventricles. The modulation of sigma 1 and IP3 receptors may lead to altered calcium handling in cardiomyocytes and thus contribute to changed sensitivity of cardiac cells to arrhythmias.

Solution of the equations of motion for a super non-Abelian sigma model in curved background by the super Poisson-Lie T-duality

International Nuclear Information System (INIS)

Eghbali, Ali

2015-01-01

The equations of motion of a super non-Abelian T-dual sigma model on the Lie supergroup (C_1"1+A) in the curved background are explicitly solved by the super Poisson-Lie T-duality. To find the solution of the flat model we use the transformation of supercoordinates, transforming the metric into a constant one, which is shown to be a supercanonical transformation. Then, using the super Poisson-Lie T-duality transformations and the dual decomposition of elements of Drinfel’d superdouble, the solution of the equations of motion for the dual sigma model is obtained. The general form of the dilaton fields satisfying the vanishing β−function equations of the sigma models is found. In this respect, conformal invariance of the sigma models built on the Drinfel’d superdouble ((C_1"1+A) , I_(_2_|_2_)) is guaranteed up to one-loop, at least.

How the early sporulation sigma factor sigmaF delays the switch to late development in Bacillus subtilis.

Science.gov (United States)

Karmazyn-Campelli, Céline; Rhayat, Lamya; Carballido-López, Rut; Duperrier, Sandra; Frandsen, Niels; Stragier, Patrick

2008-03-01

Sporulation in Bacillus subtilis is a primitive differentiation process involving two cell types, the forespore and the mother cell. Each cell implements two successive transcription programmes controlled by specific sigma factors. We report that activity of sigma(G), the late forespore sigma factor, is kept in check by Gin, the product of csfB, a gene controlled by sigma(F), the early forespore sigma factor. Gin abolishes sigma(G) transcriptional activity when sigma(G) is artificially synthesized during growth, but has no effect on sigma(F). Gin interacts strongly with sigma(G) but not with sigma(F) in a yeast two-hybrid experiment. The absence of Gin allows sigma(G) to be active during sporulation independently of the mother-cell development to which it is normally coupled. Premature sigma(G) activity leads to the formation of slow-germinating spores, and complete deregulation of sigma(G) synthesis is lethal when combined with gin inactivation. Gin allows sigma(F) to delay the switch to the late forespore transcription programme by preventing sigma(G) to take over before the cell has reached a critical stage of development. A similar strategy, following a completely unrelated route, is used by the mother cell.

Juego de rol Lean Six Sigma para empresas

OpenAIRE

Moldon Garrido, David; Porqueras Vila, Olga

2015-01-01

El objetivo del presente trabajo es la creación de un juego de rol que sirva a las empresas como formación. El fin de este juego es concienciar y formar a los trabajadores en la metodología Lean Six Sigma. Lean Six Sigma es una metodología centrada en la mejora continua para reducir los costes de la no calidad. Estos costes son aquellos generados por la producción de material o servicios que no cumplen los requerimientos del cliente. Creamos un juego de rol en el que los participantes form...

Six sigma quality for fuel manufacturing

International Nuclear Information System (INIS)

Gabbani, M.D.; Onderwater, T.

1997-01-01

It is widely recognized that operational performance in product manufacturing is largely determined by understanding and maintaining process capability. By definition, Six Sigma is a statistical unit of measure reflecting process capability that yields less' than 6.8 defects per million product produced. Statistically, this translates into obtaining a long term manufacturing process capability of ± 4.5 standard deviations about the mean within specification limits. The heart of the Six Sigma program developed by the Six Sigma Academy is what we refer to as the Breakthrough Strategy. This rigorous analytical methodology is the driving force in obtaining world class performance of Six Sigma. The methodology applies statistical and practical tools in resolving a problem or improving a product or process. The application of Six Sigma focuses on attacking process input variables (independent) rather than the output variables. Focusing on these independent variables (temperature, power, force, etc.) and the variation in the end product they create, enables us to get to the root of the problem rather than react to the symptoms of the problem. In this manner we prevent defects from occurring rather than inspecting and monitoring the product. Why the need for such an ambitious program? It is estimated that the cost of failure (rework, scrap, warranties, etc.) can be as high as 15% of sales for companies typically operating at 3-4 sigma. In achieving Six Sigma, costs of failure are typically less than 5%. The thought of reducing business costs while achieving the recognition of being our customer's premier choice provides enormous incentive to reach such status. (author)

Integrando a promoção das metodologias Lean Manufacturing e Six Sigma na busca de produtividade e qualidade numa empresa fabricante de autopeças Integrating the promotion of Lean Manufacturing and Six Sigma methodologies in search of productivity and quality in an auto parts manufacturer

Directory of Open Access Journals (Sweden)

Iris Bento da Silva

2011-01-01

Full Text Available Dentre os diversos fatores críticos de sucesso que as empresas devem considerar, destaca-se a busca por padrões cada vez mais elevados de produtividade e qualidade. Neste contexto, o objetivo deste trabalho é apresentar uma iniciativa de integrar a promoção das metodologias Lean Manufacturing e Six Sigma na busca de um melhor desempenho operacional. Essa integração combina a aplicação de elementos de Lean Manufacturing, que visa à racionalização dos fluxos de valor por meio da redução de desperdícios, com elementos de Six Sigma, que visa à sistematização do processo de análise e controle da variação em processos para se obter qualidade superior. O trabalho é baseado num estudo de caso sobre as mudanças realizadas para a acomodação desta abordagem numa empresa fabricante de autopeças. São investigados a estrutura adotada para sua promoção bem como o modo em que os projetos de melhoria são desenvolvidos por meio dela. Os resultados obtidos indicam que a iniciativa de conciliar a aplicação destas duas metodologias pode contribuir para aprimorar e tornar mais abrangente e efetivo o processo de melhoria contínua.Among the diverse critical success factors that the firms must consider, the pursuit of increasingly higher standards of productivity and quality stands out. In this context, the purpose of this article is to present an initiative to integrate the promotion of the Lean Manufacturing and Six Sigma methodologies in seeking enhanced operational performance. This integration combines the application of Lean Manufacturing elements that aim at the streamlining of value streams by the elimination of wastes with Six Sigma elements which aim at the systematization of the analysis and control of process variation for accomplishing superior quality. This work is based on a case study on the changes undertaken for the implementation of this approach in an auto parts manufacturer. The organizational structure which was

Nonlinear consider covariance analysis using a sigma-point filter formulation

Science.gov (United States)

Lisano, Michael E.

2006-01-01

The research reported here extends the mathematical formulation of nonlinear, sigma-point estimators to enable consider covariance analysis for dynamical systems. This paper presents a novel sigma-point consider filter algorithm, for consider-parameterized nonlinear estimation, following the unscented Kalman filter (UKF) variation on the sigma-point filter formulation, which requires no partial derivatives of dynamics models or measurement models with respect to the parameter list. It is shown that, consistent with the attributes of sigma-point estimators, a consider-parameterized sigma-point estimator can be developed entirely without requiring the derivation of any partial-derivative matrices related to the dynamical system, the measurements, or the considered parameters, which appears to be an advantage over the formulation of a linear-theory sequential consider estimator. It is also demonstrated that a consider covariance analysis performed with this 'partial-derivative-free' formulation yields equivalent results to the linear-theory consider filter, for purely linear problems.

Measurement of $\\sigma_{t\\bar{t}b\\bar{b}}/\\sigma_{t\\bar{t}jj}$ ratio at 13 TeV with the CMS Detector

CERN Document Server

Jo, Young-kwon

2016-01-01

The measurement of the cross section ratio $\\sigma_{t\\bar{t}b\\bar{b}}/\\sigma_{t\\bar{t}jj}$ is presented using a data sample corresponding to an integrated luminosity of 2.3~$\\rm{fb}^{-1}$ collected in pp collisions at \\\\ $\\sqrt{s}$ = 13TeV with the CMS detector at the LHC. Events with two leptons and at least four reconstructed jets, including at least two identified as b quark jets, in the final state are selected. The measured ratio is $0.022 \\pm 0.003$(stat.)$\\pm0.006$(syst.) in the full phase space. The measured cross section $\\sigma_{t\\bar{t}b\\bar{b}}$ is $3.9 \\pm 0.6$(stat.)$\\pm1.3$(syst.) pb and $\\sigma_{t\\bar{t}jj}$ is $176 \\pm 5$(stat.)$ \\pm 33 $(syst.) pb.

Crystallography of sigma phase precipitation in superaustenitic Fe-22Cr-21Ni-6Mo-0.3N stainless steels

International Nuclear Information System (INIS)

Lee, Tae Ho; Jung, Yun Chul; Kim, Sung Joon

1999-01-01

The crystallographic features of sigma phase precipitation in super austenitic Fe-22Cr-21Ni-6Mo-(0.3N) stainless steels during isothermal aging were investigated utilizing transmission electron microscopy. The sigma phase precipitated along the austenite grain boundaries even after solution treatment due to higher Mo contents and remained stable throughout aging at 900 .deg. C up to 168 hours. The sigma phase observed in this study was found to be ternary Fe-Cr-Mo sigma phase and had tetragonal structure with lattice parameters of a=9.17A and c=4.74A. The orientation relationships between the sigma phase and austenite were determined from the analyses of selected area diffraction patterns taken by various zone axes and stereo graphic analyses. The orientation relationships between sigma and austenite phases obtained in this study were as follows; 1) (110) γ ll (110) σ , [111] γ ll [001] σ and (112) γ ll (110) σ , [111] γ ll [001] σ and 2) (110) γ ll (110) σ , [112] γ ll [113] σ and (111) γ ll (332) σ , [112] γ ll [113] σ . However, the former orientation relationship was predominant throughout aging and the latter orientation relationship was scarcely observed in very limited aging condition

The SIGMA plants economic behavior

International Nuclear Information System (INIS)

Rivarola, Martin E.; Bergallo, Juan E.

1999-01-01

In this work, the economical behavior of the Uranium Enrichment Plants, built using the Gaseous Isotopic Separation using Advanced Methods (SIGMA) (Separacion Isotopica Gaseosa por Metodos Avanzados) technology is analyzed. The calculations were made using an integrated computer code, where the cost of each main component of the plant is estimated. The program computes the production cost for several configurations of enrichment cascades, each one corresponding to a production rate. The program also includes a numerical optimizer and it seeks the SIGMA optimal configuration for a given set of design parameters. The present work does not contemplate the model and calculation of the auxiliary system costs. The total amortization cost is obtained by using the cascade capital cost and assuming that the auxiliary system represents a fixed part of the total cost.The results obtained show that the SIGMA technology for Enrichment Uranium Plants could achieve economical competition in a much lower production scale than the conventional Gaseous Diffusion Enrichment Plants. (author)

Identification of D3 and sigma receptors in the rat striatum and nucleus accumbens using (+/-)-7-hydroxy-N,N-di-n-[3H]propyl-2-aminotetralin and carbetapentane.

Science.gov (United States)

Wallace, D R; Booze, R M

1995-02-01

Cross-reactions between dopamine D3 and sigma receptor ligands were investigated using (+/-)-7-hydroxy-N,N-di-n-[3H]propyl-2-aminotetralin [(+/-)-7-OH-[3H]-DPAT], a putative D3-selective radioligand, in conjunction with the unlabeled sigma ligands 1,3-di(2-tolyl)guanidine (DTG), carbetapentane, and R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane [R(-)-PPAP]. In transfected CCL1.3 mouse fibroblasts expressing the human D3 receptor, neither DTG nor carbetapentane (0.1 microM) displaced (+/-)-7-OH-[3H]DPAT binding. R(-)-PPAP (0.1 microM) displaced 39.6 +/- 1.0% of total (+/-)-7-OH-[3H]DPAT binding. In striatal and nucleus accumbens homogenates, (+/-)-7-OH-[3H]DPAT labeled a single site (15-20 fmol/mg of protein) with high (1 nM) affinity. Competition analysis with carbetapentane defined both high- and low-affinity sites in striatal (35 and 65%, respectively) and nucleus accumbens (59 and 41%, respectively) tissue, yet R(-)-PPAP identified two sites in equal proportion. Carbetapentane and R(-)-PPAP (0.1 microM) displaced approximately 20-50% of total (+/-)-7-OH-[3H]DPAT binding in striatum, nucleus accumbens, and olfactory tubercle in autoradiographic studies, with the nucleus accumbens shell subregion exhibiting the greatest displacement. To determine directly (+)-7-OH-[3H]DPAT binding to sigma receptors, saturation analysis was performed in the cerebellum while masking D3 receptors with 1 microM dopamine. Under these conditions (+)-7-OH-[3H]DPAT labeled sigma receptors with an affinity of 24 nM. These results suggest that (a) (+/-)-7-OH-[3H]DPAT binds D3 receptors with high affinity in rat brain and (b) a significant proportion of (+/-)-7-OH-[3H]DPAT binding consists of sigma 1 sites and the percentages of these sites differ among the subregions of the striatum and nucleus accumbens.

Quality and Competitiveness: A Lean Six Sigma Approach

Directory of Open Access Journals (Sweden)

Irina-Virginia Drăgulănescu

2015-11-01

Full Text Available Originally developed to improve the quality and production efficiency, Lean Six Sigma is now widely adopted in other non-manufacturing sectors such as financial, trade, services, etc. The methodology known as Lean Six Sigma combines the Six Sigma techniques, ‒ which allow companies to reduce manufacturing defects ‒ and the Lean Manufacturing principles, ‒ which help companies benefit from faster processing for lower costs and with superior quality. As a result of the research, the authors observed that, despite growing popularity and impressive outcomes obtained by some companies, the Lean Six Sigma model does not always offer the expected results. However, the research has shown that the analysed company, operating in the field of courier services has managed to boost productivity and competitiveness by implementing measures that generated added value.

Assessing precision, bias and sigma-metrics of 53 measurands of the Alinity ci system.

Science.gov (United States)

Westgard, Sten; Petrides, Victoria; Schneider, Sharon; Berman, Marvin; Herzogenrath, Jörg; Orzechowski, Anthony

2017-12-01

Assay performance is dependent on the accuracy and precision of a given method. These attributes can be combined into an analytical Sigma-metric, providing a simple value for laboratorians to use in evaluating a test method's capability to meet its analytical quality requirements. Sigma-metrics were determined for 37 clinical chemistry assays, 13 immunoassays, and 3 ICT methods on the Alinity ci system. Analytical Performance Specifications were defined for the assays, following a rationale of using CLIA goals first, then Ricos Desirable goals when CLIA did not regulate the method, and then other sources if the Ricos Desirable goal was unrealistic. A precision study was conducted at Abbott on each assay using the Alinity ci system following the CLSI EP05-A2 protocol. Bias was estimated following the CLSI EP09-A3 protocol using samples with concentrations spanning the assay's measuring interval tested in duplicate on the Alinity ci system and ARCHITECT c8000 and i2000 SR systems, where testing was also performed at Abbott. Using the regression model, the %bias was estimated at an important medical decisions point. Then the Sigma-metric was estimated for each assay and was plotted on a method decision chart. The Sigma-metric was calculated using the equation: Sigma-metric=(%TEa-|%bias|)/%CV. The Sigma-metrics and Normalized Method Decision charts demonstrate that a majority of the Alinity assays perform at least at five Sigma or higher, at or near critical medical decision levels. More than 90% of the assays performed at Five and Six Sigma. None performed below Three Sigma. Sigma-metrics plotted on Normalized Method Decision charts provide useful evaluations of performance. The majority of Alinity ci system assays had sigma values >5 and thus laboratories can expect excellent or world class performance. Laboratorians can use these tools as aids in choosing high-quality products, further contributing to the delivery of excellent quality healthcare for patients

Performance specifications and six sigma theory: Clinical chemistry and industry compared.

Science.gov (United States)

Oosterhuis, W P; Severens, M J M J

2018-04-11

Analytical performance specifications are crucial in test development and quality control. Although consensus has been reached on the use of biological variation to derive these specifications, no consensus has been reached which model should be preferred. The Six Sigma concept is widely applied in industry for quality specifications of products and can well be compared with Six Sigma models in clinical chemistry. However, the models for measurement specifications differ considerably between both fields: where the sigma metric is used in clinical chemistry, in industry the Number of Distinct Categories is used instead. In this study the models in both fields are compared and discussed. Copyright © 2018. Published by Elsevier Inc.

Six sigma and total quality management:different day, same soup?

OpenAIRE

Klefsjö, Bengt; Bergquist, Bjarne; Edgeman, R. L.

2006-01-01

  For decades now TQM has been a dominant management concept for improving competitiveness and financial results. In recent years, however, TQM seems to have lost some of its nimbus with other concepts and approaches such as lean enterprise and six sigma launched and increasingly in vogue. The aim of this paper is to look at TQM and six sigma, their backgrounds, definitions and ingredients, and their similarities and differences to see whether the two concepts really are different dishes o...

Twisted sigma-model solitons on the quantum projective line

Science.gov (United States)

Landi, Giovanni

2018-04-01

On the configuration space of projections in a noncommutative algebra, and for an automorphism of the algebra, we use a twisted Hochschild cocycle for an action functional and a twisted cyclic cocycle for a topological term. The latter is Hochschild-cohomologous to the former and positivity in twisted Hochschild cohomology results into a lower bound for the action functional. While the equations for the critical points are rather involved, the use of the positivity and the bound by the topological term lead to self-duality equations (thus yielding twisted noncommutative sigma-model solitons, or instantons). We present explicit nontrivial solutions on the quantum projective line.

Interaction of sigma factor sigmaN with Escherichia coli RNA polymerase core enzyme.

Science.gov (United States)

Scott, D J; Ferguson, A L; Gallegos, M T; Pitt, M; Buck, M; Hoggett, J G

2000-12-01

The equilibrium binding and kinetics of assembly of the DNA-dependent RNA polymerase (RNAP) sigma(N)-holoenzyme has been investigated using biosynthetically labelled 7-azatryptophyl- (7AW)sigma(N). The spectroscopic properties of such 7AW proteins allows their absorbance and fluorescence to be monitored selectively, even in the presence of high concentrations of other tryptophan-containing proteins. The 7AWsigma(N) retained its biological activity in stimulating transcription from sigma(N)-specific promoters, and in in vitro gel electrophoresis assays of binding to core RNAP from Escherichia coli. Furthermore, five Trp-->Ala single mutants of sigma(N) were shown to support growth under conditions of nitrogen limitation, and showed comparable efficiency in activating the sigma(N)-dependent nifH promoter in vivo, indicating that none of the tryptophan residues were essential for activity. The equilibrium binding of 7AWsigma(N) to core RNAP was examined by analytical ultracentrifugation. In sedimentation equilibrium experiments, absorbance data at 315 nm (which reports selectively on the distribution of free and bound 7AWsigma(N)) established that a 1:1 complex was formed, with a dissociation constant lower than 2 microM. The kinetics of the interaction between 7AWsigma(N) and core RNAP was investigated using stopped-flow spectrofluorimetry. A biphasic decrease in fluorescence intensity was observed when samples were excited at 280 nm, whereas only the slower of the two phases was observed at 315 nm. The kinetic data were analysed in terms of a mechanism in which a fast bimolecular association of sigma(N) with core RNAP is followed by a relatively slow isomerization step. The consequences of these findings on the competition between sigma(N) and the major sigma factor, sigma(70), in Escherichia coli are discussed.

Sigma virus and mutation in Drosophila melanogaster

International Nuclear Information System (INIS)

Paquin, S.L.A.

1977-01-01

- The objectives of these experiments have been (1) to verify and evidence more fully the action of sigma in causing recessive lethal mutation on the X chromosome of Drosophila, both in the male and the female germ line; (2) to extend the study of sigma-induced recessive lethal mutation to the Drosophila autosomes; (3) to explore the possibility that this mutagenesis is site-directed; (4) to study the effects of sigma virus in conjunction with radiation in increasing non-disjunction and dominant lethality. The virus increases the rate of radiation-induced nondisjunction by altering meiotic chromosomal behavior. Percentage of non-disjunction with 500 rads of x-rays in the virus-free flies was 0.176, while in sigma-containing lines it was 0.333. With high doses of either x or neutron radiation, the presence of the virus enhances the frequency of dominant lethality. The difference is especially significant with the fast neutrons. The results indicate that sigma, and presumably other viruses, are indeed environmental mutagens and are, therefore, factors in the rate of background or spontaneous mutation

X-Ray Diffraction (XRD) Characterization Methods for Sigma=3 Twin Defects in Cubic Semiconductor (100) Wafers

Science.gov (United States)

Park, Yeonjoon (Inventor); Kim, Hyun Jung (Inventor); Skuza, Jonathan R. (Inventor); Lee, Kunik (Inventor); King, Glen C. (Inventor); Choi, Sang Hyouk (Inventor)

2017-01-01

An X-ray defraction (XRD) characterization method for sigma=3 twin defects in cubic semiconductor (100) wafers includes a concentration measurement method and a wafer mapping method for any cubic tetrahedral semiconductor wafers including GaAs (100) wafers and Si (100) wafers. The methods use the cubic semiconductor's (004) pole figure in order to detect sigma=3/{111} twin defects. The XRD methods are applicable to any (100) wafers of tetrahedral cubic semiconductors in the diamond structure (Si, Ge, C) and cubic zinc-blend structure (InP, InGaAs, CdTe, ZnSe, and so on) with various growth methods such as Liquid Encapsulated Czochralski (LEC) growth, Molecular Beam Epitaxy (MBE), Organometallic Vapor Phase Epitaxy (OMVPE), Czochralski growth and Metal Organic Chemical Vapor Deposition (MOCVD) growth.

Solubility Modeling of the Binary Systems Fe(NO3)3–H2O, Co(NO3)2–H2O and the Ternary System Fe(NO3)3–Co(NO3)2–H2O with the Extended Universal Quasichemical (UNIQUAC) Model

DEFF Research Database (Denmark)

Arrad, Mouad; Kaddami, Mohammed; Goundali, Bahija El

2016-01-01

Solubility modeling in the binary system Fe(NO3)3–H2O, Co(NO3)2–H2O and the ternary system Fe(NO3)3–Co(NO3)2–H2O is presented. The extended UNIQUAC model was applied to the thermodynamic assessment of the investigated systems. The model parameters obtained were regressed simultaneously using...... the available databank but with more experimental points, recently published in the open literature. A revision of previously published parameters for the cobalt ion and new parameters for the iron(III) nitrate system are presented. Based on this set of parameters, the equilibrium constants of hydrates...

Renormalized trajectory for non-linear sigma model and improved scaling behaviour

International Nuclear Information System (INIS)

Guha, A.; Okawa, M.; Zuber, J.B.

1984-01-01

We apply the block-spin renormalization group method to the O(N) Heisenberg spin model. Extending a previous work of Hirsch and Shenker, we find the renormalized trajectory for O(infinite) in two dimensions. Four finite N models, we choose a four-parameter action near the large-N renormalized trajectory and demonstrate a remarkable improvement in the approach to continuum limit by performing Monte Carlo simulation of O(3) and O(4) models. (orig.)

$\\Lambda$ and $\\Sigma^{0}$ Pair Production in Two-Photon Collisions at LEP

CERN Document Server

Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Echenard, B.; Eline, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Ewers, A.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hakobyan, R.S.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Krenz, W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Lubelsmeyer, K.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mangeol, D.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nisati, A.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Palomares, C.; Pandoulas, D.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.O.; Prokofiev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M.A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Roux, B.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Sanders, M.P.; Schafer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schopper, H.; Schotanus, D.J.; Schwering, G.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wallraff, W.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, A.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zilizi, G.; Zimmermann, B.; Zoller, M.

2002-01-01

Strange baryon pair production in two-photon collisions is studied with the L3 detector at LEP. The analysis is based on data collected at e+e- centre-of-mass energies from 91 GeV to 208 GeV, corresponding to an integrated luminosity of 844 pb-1. The processes gamma gamma -> Lambda Anti-lambda and gamma gamma -> Sigma0 Anti-sigma0 are identified. Their cross sections as a function of the gamma gamma centre-of-mass energy are measured and results are compared to predictions of the quark-diquark model.

(-)PPAP: a new and selective ligand for sigma binding sites.

Science.gov (United States)

Glennon, R A; Battaglia, G; Smith, J D

1990-11-01

Most agents employed for the investigation of sigma (sigma) binding sites display relatively low affinity for these sites, bind both at sigma sites and at either phencyclidine (PCP) sites or dopamine receptors with similar affinity, and/or produce some dopaminergic activity in vivo. We describe a new agent, (-)PPAP or R(-)-N-(3-phenyl-n-propyl)-1-phenyl-2-aminopropane hydrochloride, that binds with high affinity and selectivity at sigma (IC50 = 24 nM) versus either PCP sites (IC50 greater than 75,000 nM) or D1 and D2 dopamine receptors (IC50 greater than 5,000 nM). The sigma affinity of this agent is comparable to that of the standard ligands (+)-3-PPP and DTG. Furthermore, although (-)PPAP is structurally related to amphetamine, it neither produces nor antagonizes amphetamine-like stimulus effect in rats trained to discriminate 1 mg/kg of S(+)amphetamine from saline.

Auriacusite, Fe[superscript 3+]Cu[superscript 2+]AsO[subscript 4]O, the first M[superscript 3+] member of the olivenite group, from the Black Pine mine, Montana, USA

Energy Technology Data Exchange (ETDEWEB)

Mills, Stuart J.; Kampf, Anthony R.; Poirier, Glenn; Raudsepp, Mati; Steele, Ian M. (CMN); (NHM-LA); (UC); (UBC)

2011-08-16

Auriacusite, ideally Fe{sup 3+}Cu{sup 2+}AsO{sub 4}O, is a new arsenate mineral (IMA2009-037) and the Fe{sup 3+} analogue of olivenite, from the Black Pine mine, 14.5 km NW of Philipsburg, Granite Co., Montana, USA. It occurs lining quartz vughs and coating quartz crystals and is associated with segnitite, brochantite, malachite, tetrahedrite and pyrite. Auriacusite forms fibrous crystals up to about 5 {micro}m in width and up to about 100 {micro}m in length, which are intergrown to form fibrous mats. Individual crystals are a brownish golden yellow, whilst the fibrous mats are ochreous yellow. The crystals have a silky lustre and a brownish yellow streak. Mohs hardness is about 3 (estimated). The fracture is irregular and the tenacity is brittle. Auriacusite crystals are biaxial (+), with {alpha} = 1.830(5), {beta} = 1.865(5) and {gamma} = 1.910(5), measured using white light, and with 2V{sub meas.} = 83(3){sup o} and 2V{sub calc.} = 84.6{sup o}. Orientation: X = a, Y = c, Z = b. Crystals are nonpleochroic or too weakly so to be observed. The empirical formula (based on 5 O atoms) is (Fe{sub 1.33}{sup 3+}Cu{sub 0.85}Zn{sub 0.03}){sub {Sigma}2.21}(As{sub 0.51}Sb{sub 0.27}Si{sub 0.04}S{sub 0.02}Te{sub 0.01}){sub {Sigma}0.85}O{sub 5}. Auriacusite is orthorhombic, space group Pnnm, a = 8.6235(7), b = 8.2757(7), c = 5.9501(5) {angstrom}, V = 424.63(6) {angstrom}{sup 3}, Z = 4. The five strongest lines in the powder X-ray diffraction pattern are [d{sub obs} in {angstrom}/(I)/hkl]: 4.884/(100)/101, 001; 2.991/(92)/220; 2.476/(85)/311; 2.416/(83)/022; 2.669/(74)/221. The crystal structure was solved from single-crystal X-ray diffraction data utilising synchrotron radiation and refined to R{sub 1} = 0.1010 on the basis of 951 unique reflections with F {alpha} > 4{sigma}F. Auriacusite is identified as a member of the olivenite group with Fe{sup 3+} replacing Zn{sup 2+} or Cu{sup 2+} in trigonal bipyramidal coordination. Evidence suggests that auriacusite is an intermediate

Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

Science.gov (United States)

Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

2017-02-01

NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

Spectroscopic properties and thermal stability of Er3+ -doped TeO2-B2O3-Nb2O5-ZnO glass for potential WDM amplifier.

Science.gov (United States)

Xu, Tiefeng; Zhang, Xudong; Li, Guangpo; Dai, Shixun; Nie, Qiuhua; Shen, Xiang; Zhang, Xianghua

2007-06-01

A series of novel 70TeO2-(15-x)B2O3-xNb2O5-15ZnO-1wt.% Er2O3 (TBN x=0, 3, 6, 9, 12 and 15 mol%) tellurite glasses were prepared. The thermal stability, absorption spectra, emission spectra, and the lifetime of the (4)I(13/2) level of Er(3+) ions were measured and investigated. Three Judd-Ofelt intensity parameters Omega(t) (t=2, 4 and 6) (Omega(2)=(5.42-6.76)x10(-20)cm(2); Omega(4)=(1.37-1.73)x10(-20)cm(2); Omega(6)=(0.70-0.94)x10(-20)cm(2)) of Er(3+) ions were calculated by Judd-Ofelt theory. It is found that the Omega(6) first increases with the increase of Nb2O5 content from 0 to 6 mol% and then decreases, which is mainly affected by the number of non-bridging oxygen ions of the glass network. The high peak of stimulated emission cross-section (sigma(e)(peak)=(0.77-0.91)x10(-20)cm(2)) of Er(3+): (4)I(13/2)-->(4)I(15/2) transition were obtained according to McCumber theory and broad full width at half maximum (FWHM=65-73 nm) of the (4)I(13/2)-->(4)I(15/2) transition of Er(3+) ions were measured. The results indicate that these new TBN glasses can be used as a candidate host material for potential broadband optical amplifiers.

Tripod sigma: results of a pro-active work stress-survey

NARCIS (Netherlands)

Nelemans, R.; Wiezer, N.; Vaas, F.; Gort, J.; Groeneweg, J.

2003-01-01

Work related stress is an important causes of disability and absenteeism. TNO Work and Employment has developed an instrument, called Tripod Sigma, that identifies risks to work stress and provides tools for remedying these risks. The Tripod Sigma model is developed analogous to the Tripod

Peningkatan performansi produksi dengan pendekatan lean six sigma

Directory of Open Access Journals (Sweden)

H. Harisupriyanto

2018-01-01

Full Text Available Abstrak Persaingan pasar tidak sekedar menjual produk akan tetapi membutuhkan kualitas produk yang semakin baik. Kondisi tersebut semakin penting bila dihubungkan dengan permintaan produk yang semakin tinggi. Untuk itu diperlukan pengolahan sumber daya yang semakin efisiensi dan effektif. Sering terjadi proses produksi berhenti dan ditaksir kerugian finansial yang tinggi. Terdapat aktifitas yang bersifat non value added. Aktifitas tersebut menyebabkan timbulnyalosses. Diperlukan cara untuk menelusuri penyebab terjadinya waste atau losses pada aktivitas produksi dengan pendekatan lean six sigma. Tools yang dipakai untuk mengidentifikasi permasalahan adalah E-DOWNTIME waste, RCA (root cause Analisys dan FMEA (Failure modes and effect analysis. Diperoleh hasil bahwavalue added activity sebesar 22%, necessary but non value added activity yaitu 44% dan nonvalue added activity sebesar 34%. Diperoleh tiga waste kritis yaitu waiting, defect dan excess processing waste. Nilai sigma awal pada defect waste yaitu sebesar 2.70;nilai sigma ini merupakan permasalahan. Rekomendasi perbaikan adalah pembuatan dan pengawasan SOP dan pengadaan pelatihan guna meningkatkan kemampuan dan keterampilan tenaga kerja. Terjadi kenaikan nilai sigma sampai 3.10 dan terjadi pengurangan biaya sampai 25%. Kata Kunci: Losses, activity, RCA, Lean, six-sigma Abstract The market competition is not just selling a product but needs a better product quality. That condition increasingly important when associated with higher product demand. It required the processing resources more efficient and effective.The production process often stops and estimated financial loss is high. There were indications of activities nonvalue added. These activities cause losses. Need a way to explore the causes of waste or losses in production activities with lean six- sigma approach.Tools used to identify the problem are E-DOWNTIME waste, RCA (root cause Analisys and FMEA (Failure modes and effects

CMOS sigma-delta converters practical design guide

CERN Document Server

De la Rosa, Jose M

2013-01-01

A comprehensive overview of Sigma-Delta Analog-to-Digital Converters (ADCs) and a practical guide to their design in nano-scale CMOS for optimal performance. This book presents a systematic and comprehensive compilation of sigma-delta converter operating principles, the new advances in architectures and circuits, design methodologies and practical considerations - going from system-level specifications to silicon integration, packaging and measurements, with emphasis on nanometer CMOS implementation. The book emphasizes practical design issues - from high-level behavioural modelling i

Optical spectroscopy of lanthanide ions in ZnO-TeO2 glasses.

Science.gov (United States)

Rolli, R; Wachtler, K; Wachtler, M; Bettinelli, M; Speghini, A; Ajò, D

2001-09-01

Zinc tellurite glasses of compositions 19ZnO-80TeO2-1Ln2O3 with Ln = Eu, Er, Nd and Tm were prepared by melt quenching. The absorption spectra were measured and from the experimental oscillator strengths of the f-->f transitions the Judd-Ofelt parameters ohm(lambda) were obtained. The values of the ohm(lambda) parameters are in the range usually observed for oxide glasses. For Nd3+ and Er3+, luminescence spectra in the near infrared were measured and the stimulated emission cross sections sigma(p) were evaluated for some laser transitions. The high values of sigma(p), especially for Nd3+, make them possible candidates for optical applications. Fluorescence line narrowing (FLN) spectra of the Eu3+ doped glass were measured at 20 K, and the energies of the Stark components of the 7F1 and 7F2 states were obtained. A crystal field analysis was carried out assuming a C2v site symmetry. The behaviour of the crystal field ratios B22/B20 and B44/B40 agrees reasonably well with the values calculated using the geometric model proposed by Brecher and Riseberg. The crystal field strength at the Eu3+ sites appears to be very low compared to other oxide glasses.

The structure of the .sigma.-ideal of .sigma.-porous sets

Czech Academy of Sciences Publication Activity Database

Zelený, M.; Pelant, Jan

2004-01-01

Roč. 45, č. 1 (2004), s. 37-72 ISSN 0010-2628 R&D Projects: GA ČR GA201/97/1161; GA ČR GA201/97/0216; GA ČR GA201/00/1466; GA AV ČR KSK1019101 Institutional research plan: CEZ:AV0Z1019905 Keywords : .sigma. proposity * descriptive set theory * .sigma.-ideal Subject RIV: BA - General Mathematics

The alternative sigma factor sigma B of Staphylococcus aureus modulates virulence in experimental central venous catheter-related infections.

Science.gov (United States)

Lorenz, Udo; Hüttinger, Christian; Schäfer, Tina; Ziebuhr, Wilma; Thiede, Arnulf; Hacker, Jörg; Engelmann, Susanne; Hecker, Michael; Ohlsen, Knut

2008-03-01

The impact of the alternative sigma factor sigma B (SigB) on pathogenesis of Staphylococcus aureus is not conclusively clarified. In this study, a central venous catheter (CVC) related model of multiorgan infection was used to investigate the role of SigB for the pathogenesis of S. aureus infections and biofilm formation in vivo. Analysis of two SigB-positive wild-type strains and their isogenic mutants revealed uniformly that the wild-type was significantly more virulent than the SigB-deficient mutant. The observed difference in virulence was apparently not linked to the capability of the strains to form biofilms in vivo since wild-type and mutant strains were able to produce biofilm layers inside of the catheter. The data strongly indicate that the alternative sigma factor SigB plays a role in CVC-associated infections caused by S. aureus.

DO3SE model applicability and O3 flux performance compared to AOT40 for an O3-sensitive tropical tree species (Psidium guajava L. 'Paluma').

Science.gov (United States)

Assis, Pedro I L S; Alonso, Rocío; Meirelles, Sérgio T; Moraes, Regina M

2015-07-01

Phytotoxic ozone (O3) levels have been recorded in the Metropolitan Region of São Paulo (MRSP). Flux-based critical levels for O3 through stomata have been adopted for some northern hemisphere species, showing better accuracy than with accumulated ozone exposure above a threshold of 40 ppb (AOT40). In Brazil, critical levels for vegetation protection against O3 adverse effects do not exist. The study aimed to investigate the applicability of O3 deposition model (Deposition of Ozone for Stomatal Exchange (DO3SE)) to an O3-sensitive tropical tree species (Psidium guajava L. 'Paluma') under the MRSP environmental conditions, which are very unstable, and to assess the performance of O3 flux and AOT40 in relation to O3-induced leaf injuries. Stomatal conductance (g s) parameterization for 'Paluma' was carried out and used to calculate different rate thresholds (from 0 to 5 nmol O3 m(-2) projected leaf area (PLA) s(-1)) for the phytotoxic ozone dose (POD). The model performance was assessed through the relationship between the measured and modeled g sto. Leaf injuries were analyzed and associated with POD and AOT40. The model performance was satisfactory and significant (R (2) = 0.56; P < 0.0001; root-mean-square error (RMSE) = 116). As already expected, high AOT40 values did not result in high POD values. Although high POD values do not always account for more injuries, POD0 showed better performance than did AOT40 and other different rate thresholds for POD. Further investigation is necessary to improve our model and also to check if there is a critical level of ozone in which leaf injuries arise. The conclusion is that the DO3SE model for 'Paluma' is applicable in the MRSP as well as in temperate regions and may contribute to future directives.

Developmental Changes in Sleep Spindle Characteristics and Sigma Power across Early Childhood

Directory of Open Access Journals (Sweden)

Ian J. McClain

2016-01-01

Full Text Available Sleep spindles, a prominent feature of the non-rapid eye movement (NREM sleep electroencephalogram (EEG, are linked to cognitive abilities. Early childhood is a time of rapid cognitive and neurophysiological maturation; however, little is known about developmental changes in sleep spindles. In this study, we longitudinally examined trajectories of multiple sleep spindle characteristics (i.e., spindle duration, frequency, integrated spindle amplitude, and density and power in the sigma frequency range (10–16 Hz across ages 2, 3, and 5 years (n=8; 3 males. At each time point, nocturnal sleep EEG was recorded in-home after 13-h of prior wakefulness. Spindle duration, integrated spindle amplitude, and sigma power increased with age across all EEG derivations (C3A2, C4A1, O2A1, and O1A2; all ps < 0.05. We also found a developmental decrease in mean spindle frequency (p<0.05 but no change in spindle density with increasing age. Thus, sleep spindles increased in duration and amplitude but decreased in frequency across early childhood. Our data characterize early developmental changes in sleep spindles, which may advance understanding of thalamocortical brain connectivity and associated lifelong disease processes. These findings also provide unique insights into spindle ontogenesis in early childhood and may help identify electrophysiological features related to healthy and aberrant brain maturation.

Pion--nucleon sigma-commutator

International Nuclear Information System (INIS)

Banerjee, M.K.; Cammarata, J.B.

1977-07-01

The reasons for the large discrepancies in the magnitude of the πN sigma-commutator, sigma(πN), obtained by several authors are discussed using dynamic theory of the πN scattering amplitude. With sigma(πN) approximately 25 MeV this theory reproduces reasonably well both the experimental S-wave phase shifts at low energies and the amplitudes C approximately/sup(+)/(ν=0,t less than or equal to 0) determined by Langbein. In the method of Cheng and Dashen the value of sigma(πN) is obtained from these amplitudes by extrapolation to t = 2m 2 /sub π/. A study of the experimental D-wave ''scattering lengths'' implies that the coefficient of the term quadratic in t in the Hoehler expansion of C approximately/sup(+)/(0,t) is negative. Adding such a term to the results of the S-wave theory will tend to improve the agreement for C approximately/sup (+)/(0,t less than or equal to 0). These results suggest that the large ''world value'' sigma(πN) = 65 +- 5 MeV obtained using the Cheng-Dashen method is a consequence of errors in the extrapolation of amplitudes to the unphysical point ν = 0, t = 2m 2 /sub π/. Only the smaller value sigma(πN) approximately 25 MeV appears to be consistent with the experimental data and theoretical constraints

Kinetics of sigma phase formation in a Duplex Stainless Steel

Directory of Open Access Journals (Sweden)

Rodrigo Magnabosco

2009-09-01

Full Text Available This work determines the kinetics of sigma phase formation in UNS S31803 Duplex Stainless Steel (DSS, describing the phase transformations that occur in isothermal aging between 700 and 900 ºC for time periods up to 1032 hours, allowing the determination of the Time-Temperature-Precipitation (TTP diagram for sigma phase and proposing a model to predict the kinetics of sigma phase formation using a Johnson-Mehl-Avrami (JMA type expression. The higher kinetics of sigma phase formation occurs at 850 ºC. However, isothermal aging between 700 and 900 ºC for time periods up to 1032 hours are not sufficient to the establishment of thermodynamic equilibrium. Activation energy for both nucleation and growth of sigma phase is determined (185 kJ.mol-1 and its value is equivalent to the activation energy for Cr diffusion in ferrite, indicating that diffusion of Cr is probably the major thermally activated process involved in sigma phase formation. The determined JMA type expression presents good fit with experimental data between 700 and 850 ºC.

DEVELOPMENT OF MATHEMATICAL MODELS FOR OPTIMAL PREVENTIVE MAINTENANCE POLICY IN A STEEL INDUSTRY : SIX SIGMA APPROACH

Directory of Open Access Journals (Sweden)

N. V. R. Naidu

2011-09-01

Full Text Available This paper deals with a critical evaluation of the Preventive Maintenance system in steel industry. This study helps in implementing Six Sigma solutions to reduce the down time of two critical machines i.e., Electric Arc Furnace (EAF and Billet Casting Machine (BCM. It is clear from the analysis of EAF and BCM respectively that, variations in output are quite possible because the machines output not only depend on maintenance time but also on several other variables. Further, the objective is to design a preventive maintenance programme on the same equipment situated in the plant using Six Sigma. The breakdown of these equipments could very well affect the production rate. For this, the mathematical models have been developed and these models are used to obtain the optimum preventive maintenance frequency for minimizing the down time and maximizing the profits.

Continuous time sigma delta ADC design and non-idealities analysis

International Nuclear Information System (INIS)

Yuan Jun; Chen Zhenhai; Yang Yintang; Zhang Zhaofeng; Wu Jun; Wang Chao; Qian Wenrong

2011-01-01

A wide bandwidth continuous time sigma delta ADC is implemented in 130 nm CMOS. A detailed non-idealities analysis (excess loop delay, clock jitter, finite gain and GBW, comparator offset and DAC mismatch) is performed developed in Matlab/Simulink. This design is targeted for wide bandwidth applications such as video or wireless base-stations. Athird-order continuous time sigma delta modulator comprises a third-order RC operational-amplifier-based loop filter and 3-bit internal quantizer operated at 512 MHz clock frequency. The sigma delta ADC achieves 60 dB SNR and 59.3 dB SNDR over a 16-MHz signal band at an OSR of 16. The power consumption of the CT sigma delta modulator is 22 mW from the 1.2-V supply. (semiconductor integrated circuits)

Decays of open charmed mesons in the extended Linear Sigma Model

Directory of Open Access Journals (Sweden)

Eshraim Walaa I.

2014-01-01

Full Text Available We enlarge the so-called extended linear Sigma model (eLSM by including the charm quark according to the global U(4r × U(4l chiral symmetry. In the eLSM, besides scalar and pseudoscalar mesons, also vector and axial-vector mesons are present. Almost all the parameters of the model were fixed in a previous study of mesons below 2 GeV. In the extension to the four-flavor case, only three additional parameters (all of them related to the bare mass of the charm quark appear.We compute the (OZI dominant strong decays of open charmed mesons. The results are compatible with the experimental data, although the theoretical uncertainties are still large.

sigma opiates and certain antipsychotic drugs mutually inhibit (+)-[3H]SKF 10,047 and [3H]haloperidol binding in guinea pig brain membranes

International Nuclear Information System (INIS)

Tam, S.W.; Cook, L.

1984-01-01

The relationship between binding of antipsychotic drugs and sigma psychotomimetic opiates to binding sites for the sigma agonist (+)-[ 3 H]SKF 10,047 (N-allylnormetazocine) and to dopamine D 2 sites was investigated. In guinea pig brain membranes, (+)-[ 3 H]SKF 10,047 bound to single class of sites with a K/sub d/ of 4 x 10 -8 M and a B/sub max/ of 333 fmol/mg of protein. This binding was different from μ, kappa, or delta opiate receptor binding. It was inhibited by opiates that produce psychotomimetic activities but not by opiates that lack such activities. Some antipsychotic drugs inhibited (+)-[ 3 H]SKF 10,047 binding with high to moderate affinities in the following order of potency: haloperidol > perphenazine > fluphenazine > acetophenazine > trifluoperazine > molindone greater than or equal to pimozide greater than or equal to thioridazine greater than or equal to chlorpromazine greater than or equal to triflupromazine. However, there were other antipsychotic drugs such as spiperone and clozapine that showed low affinity for the (+)-[ 3 H]SKF 10,047 binding sites. Affinities of antipsychotic drugs for (+)-[ 3 H]SKF 10,047 binding sites did not correlate with those for [ 3 H]spiperone (dopamine D 2 ) sites. [ 3 H]-Haloperidol binding in whole brain membranes was also inhibited by the sigma opiates pentazocine, cyclazocine, and (+)-[ 3 H]SKF 10,047. In the striatum, about half of the saturable [ 3 H]haloperidol binding was to [ 3 H]spiperone (D 2 ) sites and the other half was to sites similar to (+)-[ 3 H]SKF 10,047 binding sites. 15 references, 4 figures, 1 table

Narrow Sigma -hypernuclear states

CERN Document Server

Gal, A

1980-01-01

It is shown that the spin-isospin dependence of low-energy Sigma N to Lambda N conversion leads to substantial quenching of nuclear-matter estimates of the widths of some Sigma -hypernuclear states produced in (K/sup -/, pi ) reactions, to a level below 10 MeV. The estimated widths compare favorably with those of the Sigma -hypernuclear peaks recently observed at CERN for /sup 7/Li, /sup 9/Be, and /sup 12/C. Tentative quantum number assignments are suggested for these states. (10 refs).

Design of the 12-bit Delta-Sigma Modulator using SC Technique for Vibration Sensor Output Processing

Directory of Open Access Journals (Sweden)

M. Pavlik

2012-04-01

Full Text Available The work deals with the design of the 12-bit Delta-Sigma modulator using switched capacitors (SC technique. The modulator serves to vibration sensor output processing. The first part describes the Delta-Sigma modulator parameters definition. Results of the proposed topology ideal model were presented as well. Next, the Delta-Sigma modulator circuitry on the transistor level was done. The ONSemiconductor I2T100 0.7 um CMOS technology was used for design. Then, the Delta-Sigma modulator nonidealities were simulated and implemented into the MATLAB ideal model of the modulator. The model of real Delta-Sigma modulator was derived. Consequently, modulator coefficients were optimized. Finally, the corner analysis of the Delta-Sigma modulator with the optimized coefficients was simulated. The value of SNDR = 82.2 dB (ENOB = 13.4 bits was achieved.

Genome-scale reconstruction of the sigma factor network in Escherichia coli: topology and functional states

DEFF Research Database (Denmark)

Cho, Byung-Kwan; Kim, Donghyuk; Knight, Eric M.

2014-01-01

Background: At the beginning of the transcription process, the RNA polymerase (RNAP) core enzyme requires a sigma-factor to recognize the genomic location at which the process initiates. Although the crucial role of sigma-factors has long been appreciated and characterized for many individual...... to transcription units (TUs), representing an increase of more than 300% over what has been previously reported. The reconstructed network was used to investigate competition between alternative sigma-factors (the sigma(70) and sigma(38) regulons), confirming the competition model of sigma substitution...

A study of the reactions $\\pi^{-}p\\rightarrow K^{*}X, K^{*}\\Sigma$ and $K^{*}Y1^{*}$ (1385) at 3.93 GeV/c

CERN Document Server

Yaffe, D; Chaloupka, V; Ferrando, A; Korkea-Aho, M K; Losty, Michael J; Montanet, Lucien; Paul, E; Zatz, J; Zieminski, Z; Abramovich, M no 1; Chaloupka, V no 1; Ferrando, A no 1; Korkea-Aho, M no 1; Losty, M J no 1; Montanet, L no 1; Paul, E no 1; Zatz, J no 1; Zieminski, Z no 1; Yaffe, D no 1

1974-01-01

The authors have investigated the final states K*/sup 0/(890) Lambda , K*/sup 0/(890) Sigma /sup 0/ and K*/sup 0/(890) Y/sub 1/*/sup 0/(1385) produced in pi /sup -/p interactions at 3.93 GeV/c. They present the differential cross sections and spin density matrix elements for the resonances as functions of momentum transfer, as well as the Lambda and Sigma /sup 0/ polarizations. The Sigma /sup 0/ polarization is found to be positive and maximal. An amplitude analysis is performed for the K* Lambda and K* Sigma /sup 0/ reactions, and it is found that one natural parity transversity amplitude is dominant for the latter. (15 refs).

Bond breaking and bond making in tetraoxygen: analysis of the O2(X3Sigma(g)-) + O2(X3Sigma(g)-) O4 reaction using the electron pair localization function.

Science.gov (United States)

Scemama, Anthony; Caffarel, Michel; Ramírez-Solís, Alejandro

2009-08-06

We study the nature of the electron pairing at the most important critical points of the singlet potential energy surface of the 2O2 O4 reaction and its evolution along the reaction coordinate using the electron pair localization function (EPLF) [Scemama, A.; Chaquin, P.; Caffarel, M. J. Chem. Phys. 2004, 121, 1725]. To do that, the 3D topology of the EPLF calculated with quantum Monte Carlo (at both variational and fixed-node-diffusion Monte Carlo levels) using Hartree-Fock, multiconfigurational CASSCF, and explicitly correlated trial wave functions is analyzed. At the O4 equilibrium geometry the EPLF analysis reveals four equivalent covalent bonds and two lone pairs on each oxygen atom. Along the reaction path toward dissociation it is found that the two oxygen-oxygen bonds are not broken simultaneously but sequentially, and then the lone pairs are rearranged. In a more general perspective, the usefulness of the EPLF as a unique tool to analyze the topology of electron pairing in nontrivial chemical bonding situations as well as to visualize the major steps involved in chemical reactivity is emphasized. In contrast with most standard schemes to reveal electron localization (atoms in molecules, electron localization function, natural bond orbital, etc.), the newly introduced EPLF function gives a direct access to electron pairings in molecules.

arXiv Evidence for the rare decay $\\Sigma^+ \\to p \\mu^+ \\mu^-$

CERN Document Server

Aaij, Roel; LHCb Collaboration; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Alfonso Albero, Alejandro; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Atzeni, Michele; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Baranov, Alexander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Beiter, Andrew; Bel, Lennaert; Beliy, Nikita; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Beranek, Sarah; Berezhnoy, Alexander; Bernet, Roland; Berninghoff, Daniel; Bertholet, Emilie; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Birnkraut, Alex; Bizzeti, Andrea; Bjørn, Mikkel; Blake, Thomas; Blanc, Frederic; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bordyuzhin, Igor; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brodzicka, Jolanta; Brundu, Davide; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Byczynski, Wiktor; Cadeddu, Sandro; Cai, Hao; Calabrese, Roberto; Calladine, Ryan; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Chapman, Matthew George; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu Faye; Chitic, Stefan-Gabriel; Chobanova, Veronika; Chrzaszcz, Marcin; Chubykin, Alexsei; Ciambrone, Paolo; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collins, Paula; Colombo, Tommaso; Comerma-Montells, Albert; Contu, Andrea; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Da Silva, Cesar Luiz; Dall'Occo, Elena; Dalseno, Jeremy; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Del Buono, Luigi; Dembinski, Hans Peter; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Nezza, Pasquale; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Douglas, Lauren; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Durante, Paolo; Durham, John Matthew; Dutta, Deepanwita; Dzhelyadin, Rustem; Dziewiecki, Michal; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fazzini, Davide; Federici, Luca; Ferguson, Dianne; Fernandez, Gerard; Fernandez Declara, Placido; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Lopes, Lino; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gabriel, Emmy; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Govorkova, Ekaterina; Grabowski, Jascha Peter; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greim, Roman; Griffith, Peter; Grillo, Lucia; Gruber, Lukas; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hancock, Thomas Henry; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Hasse, Christoph; Hatch, Mark; He, Jibo; Hecker, Malte; Heinicke, Kevin; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hopchev, Plamen Hristov; Hu, Wenhua; Huang, Wenqian; Huard, Zachary; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Ibis, Philipp; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kazeev, Nikita; Kecke, Matthieu; Keizer, Floris; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kim, Kyung Eun; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Klimkovich, Tatsiana; Koliiev, Serhii; Kolpin, Michael; Kopecna, Renata; Koppenburg, Patrick; Kosmyntseva, Alena; Kotriakhova, Sofia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreps, Michal; Kress, Felix Johannes; Krokovny, Pavel; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Pei-Rong; Li, Tenglin; Li, Yiming; Li, Zhuoming; Liang, Xixin; Likhomanenko, Tatiana; Lindner, Rolf; Lionetto, Federica; Lisovskyi, Vitalii; Liu, Xuesong; Loh, David; Loi, Angelo; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Macko, Vladimir; Mackowiak, Patrick; Maddrell-Mander, Samuel; Maev, Oleg; Maguire, Kevin; Maisuzenko, Dmitrii; Majewski, Maciej Witold; Malde, Sneha; Malecki, Bartosz; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Marangotto, Daniele; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Mead, James Vincent; Meadows, Brian; Meaux, Cedric; Meier, Frank; Meinert, Nis; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Millard, Edward James; Minard, Marie-Noelle; Minzoni, Luca; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Mombächer, Titus; Monroy, Igancio Alberto; Monteil, Stephane; Morandin, Mauro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Ossowska, Anna; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palutan, Matteo; Panshin, Gennady; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Pereima, Dmitrii; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pietrzyk, Guillaume; Pikies, Malgorzata; Pinci, Davide; Pisani, Flavio; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poli Lener, Marco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Ponce, Sebastien; Popov, Alexander; Popov, Dmitry; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Pullen, Hannah Louise; Punzi, Giovanni; Qian, Wenbin; Qin, Jia-Jia; Quagliani, Renato; Quintana, Boris; Rachwal, Bartlomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Ravonel Salzgeber, Melody; Reboud, Meril; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Robbe, Patrick; Robert, Arnaud; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Ruiz Vidal, Joan; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarpis, Gediminas; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schreiner, HF; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepulveda, Eduardo Enrique; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavomira; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stepanova, Margarita; Stevens, Holger; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Stramaglia, Maria Elena; Straticiuc, Mihai; Straumann, Ulrich; Strokov, Sergey; Sun, Jiayin; Sun, Liang; Swientek, Krzysztof; Syropoulos, Vasileios; Szumlak, Tomasz; Szymanski, Maciej Pawel; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Tourinho Jadallah Aoude, Rafael; Tournefier, Edwige; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Usachov, Andrii; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagner, Alexander; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Verlage, Tobias Anton; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Walsh, John; Wang, Jianchun; Wang, Yilong; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Weisser, Constantin; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Winn, Michael Andreas; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wyllie, Kenneth; Xie, Yuehong; Xu, Menglin; Xu, Qingnian; Xu, Zehua; Xu, Zhirui; Yang, Zhenwei; Yang, Zishuo; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zonneveld, Jennifer Brigitta; Zucchelli, Stefano

2018-06-01

A search for the rare decay $\\Sigma^+ \\to p \\mu^+ \\mu^-$ is performed using $pp$ collision data recorded by the LHCb experiment at centre-of-mass energies $\\sqrt{s} = 7$ and $8$ TeV, corresponding to an integrated luminosity of $3 fb^{-1}$. An excess of events is observed with respect to the background expectation, with a signal significance of 4.1 standard deviations. No significant structure is observed in the dimuon invariant mass distribution, in contrast with a previous result from the HyperCP experiment. The measured $\\Sigma^+ \\to p \\mu^+ \\mu^-$ branching fraction is $(2.2\\,^{+\\,1.8}_{-\\,1.3})\\times 10^{-8}$, where statistical and systematic uncertainties are included, which is consistent with the Standard Model prediction.

Aplicação do programa Seis Sigma em uma indústria de abate de frangos - doi: 10.4025/actascitechnol.v32i2.527

Directory of Open Access Journals (Sweden)

Roselis Natalina Mazzuchetti

2010-07-01

Full Text Available Nos últimos anos, a indústria de abate de frango busca fortalecer seus processos, visando atender às necessidades de mercado e, para contribuir com o desenvolvimento desses processos, novos métodos têm sido implantados, entre os quais se destaca o programa Seis Sigma. O presente estudo mostra a utilização deste Programa em um abatedouro de frangos com o objetivo de demonstrar as melhores práticas para a definição e condução de um projeto centrado na melhoria da qualidade dos processos. Para tanto, foram definidos a metodologia e os critérios para a identificação de problemas e a seleção de projetos, além de se ter aplicado o programa Seis Sigma com a utilização do DMAIC em um projeto previamente selecionado, buscando-se demonstrar o desenvolvimento do Programa e utilizando-se mapa de raciocínio. A aplicação do projeto é demonstrada em seis fases, por meio de um mapa de raciocínio para cada fase ou etapa do programa, que detalha as técnicas estatísticas utilizadas até a fase do plano de ação. As fases de verificação e padronização dos processos não são contempladas neste estudo. Os resultados finais demonstram os benefícios da utilização do Programa e a importância da manutenção de banco de dados com o envolvimento das pessoas para o seu sucesso.

On the algebraic structure of self-dual gauge fields and sigma models

International Nuclear Information System (INIS)

Bais, F.A.; Sasaki, R.

1983-01-01

An extensive and detailed analysis of self-dual gauge fields, in particular with axial symmetry, is presented, culminating in a purely algebraic procedure to generate solutions. The method which is particularly suited for the construction of multimonopole solutions for a theory with arbitrary G, is also applicable to a wide class of non-linear sigma models. The relevant symmetries as well as the associated linear problems which underly the exact solubility of the problem, are constructed and discussed in detail. (orig.)

Edge states and conformal boundary conditions in super spin chains and super sigma models

International Nuclear Information System (INIS)

Bondesan, Roberto; Jacobsen, Jesper L.; Saleur, Hubert

2011-01-01

The sigma models on projective superspaces CP N+M-1|N with topological angle θ=πmod2π flow to non-unitary, logarithmic conformal field theories in the low-energy limit. In this paper, we determine the exact spectrum of these theories for all open boundary conditions preserving the full global symmetry of the model, generalizing recent work on the particular case M=0 [C. Candu et al., JHEP 1002 (2010) 015]. In the sigma model setting, these boundary conditions are associated with complex line bundles, and are labelled by an integer, related with the exact value of θ. Our approach relies on a spin chain regularization, where the boundary conditions now correspond to the introduction of additional edge states. The exact values of the exponents then follow from a lengthy algebraic analysis, a reformulation of the spin chain in terms of crossing and non-crossing loops (represented as a certain subalgebra of the Brauer algebra), and earlier results on the so-called one- and two-boundary Temperley-Lieb algebras (also known as blob algebras). A remarkable result is that the exponents, in general, turn out to be irrational. The case M=1 has direct applications to the spin quantum Hall effect, which will be discussed in a sequel.

Edge states and conformal boundary conditions in super spin chains and super sigma models

Energy Technology Data Exchange (ETDEWEB)

Bondesan, Roberto, E-mail: roberto.bondesan@cea.f [LPTENS, Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris (France); Institute de Physique Theorique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Jacobsen, Jesper L. [LPTENS, Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris (France); Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris (France); Saleur, Hubert [Institute de Physique Theorique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Physics Department, USC, Los Angeles, CA 90089-0484 (United States)

2011-08-11

The sigma models on projective superspaces CP{sup N+M-1{vert_bar}N} with topological angle {theta}={pi}mod2{pi} flow to non-unitary, logarithmic conformal field theories in the low-energy limit. In this paper, we determine the exact spectrum of these theories for all open boundary conditions preserving the full global symmetry of the model, generalizing recent work on the particular case M=0 [C. Candu et al., JHEP 1002 (2010) 015]. In the sigma model setting, these boundary conditions are associated with complex line bundles, and are labelled by an integer, related with the exact value of {theta}. Our approach relies on a spin chain regularization, where the boundary conditions now correspond to the introduction of additional edge states. The exact values of the exponents then follow from a lengthy algebraic analysis, a reformulation of the spin chain in terms of crossing and non-crossing loops (represented as a certain subalgebra of the Brauer algebra), and earlier results on the so-called one- and two-boundary Temperley-Lieb algebras (also known as blob algebras). A remarkable result is that the exponents, in general, turn out to be irrational. The case M=1 has direct applications to the spin quantum Hall effect, which will be discussed in a sequel.

Multiple pathways of sigma(1) receptor ligand uptakes into primary cultured neuronal cells.

Science.gov (United States)

Yamamoto, H; Karasawa, J; Sagi, N; Takahashi, S; Horikomi, K; Okuyama, S; Nukada, T; Sora, I; Yamamoto, T

2001-08-03

Although many antipsychotics have affinities for sigma receptors, the transportation pathway of exogenous sigma(1) receptor ligands to intracellular type-1 sigma receptors are not fully understood. In this study, sigma(1) receptor ligand uptakes were studied using primary cultured neuronal cells. [(3)H](+)-pentazocine and [(3)H](R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), used as a selective sigma(1) receptor ligands, were taken up in a time-, energy- and temperature-dependent manner, suggesting that active transport mechanisms were involved in their uptakes. sigma(1) receptor ligands taken up into primary cultured neuronal cells were not restricted to agonists, but also concerned antagonists. The uptakes of these ligands were mainly Na(+)-independent. Kinetic analysis of [(3)H](+)-pentazocine and [(3)H]MS-377 uptake showed K(m) values (microM) of 0.27 and 0.32, and V(max) values (pmol/mg protein/min) of 17.4 and 9.4, respectively. Although both ligands were incorporated, the pharmacological properties of these two ligands were different. Uptake of [(3)H](+)-pentazocine was inhibited in the range 0.4-7.1 microM by all the sigma(1) receptor ligands used, including N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethylamine monohydrochloride (NE-100), a selective sigma(1) receptor ligand. In contrast, the inhibition of [(3)H]MS-377 uptake was potently inhibited by haloperidol, characterized by supersensitivity (IC(50), approximately 2 nM) and was inhibited by NE-100 with low sensitivity (IC(50), 4.5 microM). Moreover, kinetic analysis revealed that NE-100 inhibited [(3)H]MS-377 uptake in a noncompetitive manner, suggesting that NE-100 acted at a site different from the uptake sites of [(3)H]MS-377. These findings suggest that there are at least two uptake pathways for sigma(1) receptor ligands in primary cultured neuronal cells (i.e. a haloperidol-sensitive pathway and another, unclear, pathway). In

Lean Six Sigma in financial services

NARCIS (Netherlands)

de Koning, H.; Does, R.J.M.M.; Bisgaard, S.

2008-01-01

Lean Thinking and Six Sigma are typically considered as separate approaches to process innovation, with complementary strengths. When combined as Lean Six Sigma, this approach provides a unified framework for systematically developing innovations. Lean Six Sigma can also bring about significant

Synthesis–property relationship in thermoelectric Sr 1− x Yb x TiO 3− δ ceramics

KAUST Repository

Bhattacharya, S

2014-08-22

The electronic transport properties of a series of Sr1-xYbxTiO3-delta (x = 0.05, 0.1) ceramics are investigated as a function of solid-state reaction (SSR) parameters, specifically calcination steps. It was found that the electrical conductivity (sigma) increases almost by a factor of 6, through the optimization of SSR parameters. The enhancement in the electrical conductivity leads to an enhancement in the thermoelectric power factor by a factor of 3. In addition, the lattice thermal conductivity (k(L)) of the Sr1-xYbxTiO3-delta ceramics is suppressed with increasing Yb-doping, supposedly due to heavier atomic mass of Yb substituted at the Sr site and a smaller ionic radii of Yb+3 with respect to Sr+2 ions. However, our model calculations indicate that strain-field effect, which occurs due to the difference in ionic radii, is the more prominent phonon scattering mechanism in the Yb-doped SrTiO3. This work is an extension of our previous study on the underlying phonon scattering mechanisms in the Y-doped SrTiO3, which would provide new insight into thermal transport in doped SrTiO3 and could be used as a guideline for more effective material synthesis.

Correlation holography: imaging of atoms when sigma/sub inelastic//sup >>sigma/elastic

International Nuclear Information System (INIS)

Csonka, P.L.

1979-01-01

Atomic-scale resolution of details is possible with this method, even if protons interact with the atoms overwhelmingly inelastically, i.e. when sigma/sub inelastic/ >>sigma/sub elastic/. Observation of small objects is compatible with quantum mechanics even if the disturbance of the object caused by the observation process is arbitrarily small

Design for six sigma: A review

Directory of Open Access Journals (Sweden)

Kouroush Jenab

2018-01-01

Full Text Available Six Sigma is recognized as an essential tool for continuous improvement of quality. A large num-ber of publications by various authors reflect the interest in this technique. Reviews of literature on Six Sigma have been done in the past by a few authors. However, considering the contributions in the recent times, a more comprehensive review is attempted here. The authors have examined vari-ous papers and have proposed a different scheme of classification. In addition, certain gaps that would provide hints for further research in Six Sigma have been identified. As a results the rela-tionship between Six Sigma, Design for Six Sigma (DFSS, and how these two concepts support the quality system for organizational learning and innovation performance have been discussed that would help researchers, academicians and practitioners to take a closer look at the growth, devel-opment and applicability of Six Sigma in Design.

(2,0)-Super-Yang-Mills coupled to non-linear {sigma}-model

Energy Technology Data Exchange (ETDEWEB)

Goes-Negrao, M.S.; Penna-Firme, A.B. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Negrao, M.R. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

1999-07-01

Considering a class of (2,0)-super yang-Mills multiplets that accommodate a pair of independent gauge potentials in connection with a single symmetry group, we present here their coupling to ordinary matter to non-linear {sigma}-models in (2,0)-superspace. The dynamics and the coupling of the gauge potentials are discussed and the interesting feature that comes out is a sort of chirality for one of the gauge potentials are discussed and the interesting feature that comes out is a sort of chirality for one of the gauge potentials once light-cone coordinates are chosen. (author)

DESIGN FOR SIX SIGMA

Directory of Open Access Journals (Sweden)

Liem Ferryanto

2007-01-01

Full Text Available This article provides a step by step process of executing analytical or computer based Design for Six Sigma using a Sliding Door project as an example. It comprises of identification of Voice Of the Customer (VOC, transformation of VOC to what it is called Critical To Quality characteristics (CTQs, modeling of system transfers function, optimal and robust solutions, and tolerance design approach

Magnetic properties of three-dimensional Hubbard-sigma model

International Nuclear Information System (INIS)

Yamamoto, Hisashi; Ichinose, Ikuo; Tatara, Gen; Matsui, Tetsuo.

1989-11-01

It is broadly viewed that the magnetism may play an important role in the high-T c superconductivity in the lamellar CuO 2 materials. In this paper, based on a Hubbard-inspired CP 1 or S 2 nonlinear σ model, we give a quantitative study of some magnetic properties in and around the Neel ordered state of three-dimensional quantum antiferromagnets such as La 2 CuO 4 with and without small hole doping. Our model is a (3+1) dimensional effective field theory describing the low energy spin dynamics of a three-dimensional Hubbard model with a very weak interlayer coupling. The effect of hole dynamics is taken into account in the leading approximation by substituting the CP 1 coupling with an 'effective' one determined by the concentration and the one-loop correction of hole fermions. A stationary-phase equation for the one-loop effective potential of S 2 model is analyzed numerically. The behavior of Neel temperature, magnetization (long range Neel order), spin correlation length, etc as functions of anisotropic parameter, temperature, hole concentrations, etc are investigated in detail. A phase diagram is also supported by the renormlization group analysis. The results show that our anisotropic field theory model with certain values of parameters could give a reasonably well description of the magnetic properties indicated by some experiments on pure and doped La 2 CuO 4 . (author)

Observation of out-of-phase bilayer plasmons in $YBa_{2}Cu_{3}O_{7-delta}$

NARCIS (Netherlands)

Grüninger, M.; Marel, D. van der; Tsvetkov, A. A.; Erb, A.

1999-01-01

Published in: Phys. Rev. Lett. 84 (2000) 1575 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: The temperature dependence of the c-axis optical conductivity sigma(ømega) of optimally and overdoped YBa_2Cu_3O_x (x=6.93 and 7) is reported in the far- (FIR) and

Getting the sigma in the M_BH - sigma relation right

Science.gov (United States)

van der Marel, Roeland

2017-08-01

The relation between the mass of the central supermassive black hole (M_BH) and the velocity dispersion of its host spheroid (sigma) is fundamental for our understanding of galaxy evolution and its relation to their nuclei. Correspondingly many HST orbits have been invested in determining accurate M_BH masses. Surprisingly little has been done on standardizing the other axis, i.e. sigma measurements. These values are often derived from various long-slit datasets at different physical radii of the galaxy and no homogeneous definition has been given. We propose to remedy this situation by using our dataset of MUSE and PPAK kinematic maps out to 1 R_e of galaxies with a secure black hole mass. These data are useful for large scale kinematics, however, obtaining velocity dispersions at small radii is not possible. To measure velocity dispersions at small radii we require high-spatial resolution spectroscopy as provided by HST/STIS. In addtion, high-resolution photometric data is needed to define consistent apertures in each galaxy. We therefore propose to use the unique capabilities of HST and harvest years of efforts to collect archival spectroscopic and imaging data for BH host galaxies. This will allow creating a catalog of sigma values, calculated in various ways and at various radii and to re-calibrate the M_BH - sigma relation.

Nonlinear integral equations for the sausage model

Science.gov (United States)

Ahn, Changrim; Balog, Janos; Ravanini, Francesco

2017-08-01

The sausage model, first proposed by Fateev, Onofri, and Zamolodchikov, is a deformation of the O(3) sigma model preserving integrability. The target space is deformed from the sphere to ‘sausage’ shape by a deformation parameter ν. This model is defined by a factorizable S-matrix which is obtained by deforming that of the O(3) sigma model by a parameter λ. Clues for the deformed sigma model are provided by various UV and IR information through the thermodynamic Bethe ansatz (TBA) analysis based on the S-matrix. Application of TBA to the sausage model is, however, limited to the case of 1/λ integer where the coupled integral equations can be truncated to a finite number. In this paper, we propose a finite set of nonlinear integral equations (NLIEs), which are applicable to generic value of λ. Our derivation is based on T-Q relations extracted from the truncated TBA equations. For a consistency check, we compute next-leading order corrections of the vacuum energy and extract the S-matrix information in the IR limit. We also solved the NLIE both analytically and numerically in the UV limit to get the effective central charge and compared with that of the zero-mode dynamics to obtain exact relation between ν and λ. Dedicated to the memory of Petr Petrovich Kulish.

Barriers of six sigma in healthcare organizations

Directory of Open Access Journals (Sweden)

Serkan Deniz

2018-09-01

Full Text Available Six Sigma approach is based on decreasing defects and variations in the products and processes, and it provides important benefits to healthcare organizations. This study aims to identify managers’ opinions, who work in private healthcare organizations, about the reasons behind not using Six Sigma in their organizations. The research was performed between December 2016 and March 2018 in private healthcare organizations (private hospitals and medical centers operating in Turkey and not using Six Sigma approach. Data were collected from managers, who have knowledge about Six Sigma, through using surveys. In this study, survey methodology was used to collect data. According to the results, the biggest barrier related to not using Six Sigma is based on the lack of knowledge about Six Sigma. The other important barrier about the diffusion of Six Sigma within this organizations is related to the lack of support from top management and leaders. Another finding about the reasons of not applying Six Sigma approach is that there is not a statistically significant difference among managers in terms of their managerial position. In order to overcome the lack of knowledge about Six Sigma, it is advised that managers should take steps in the direction of promoting Six Sigma within their current organization, and provide necessary support and leadership about the process.

Isomorphism and the #betta#-function of the non-linear sigma model in symmetric spaces

International Nuclear Information System (INIS)

Hikami, S.

1983-01-01

The renormalization group #betta#-function of the non-linear sigma model in symmetric spaces is discussed via the isomorphic relation and the reciprocal relation about a parameter α. The four-loop term is investigated and the symmetric properties of the #betta#-function are studied. The four-loop term in the #betta#-function is shown to be vanishing for the orthogonal Anderson localization problem. (orig.)

Evolution of metastable state molecules N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) in a nanosecond pulsed discharge: A particle-in-cell/Monte Carlo collisions simulation

Energy Technology Data Exchange (ETDEWEB)

Gao Liang; Sun Jizhong; Feng Chunlei; Bai Jing; Ding Hongbin [School of Physics and Optical Electronic Technology, Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Chinese Ministry of Education, Dalian University of Technology, Dalian 116024 (China)

2012-01-15

A particle-in-cell plus Monte Carlo collisions method has been employed to investigate the nitrogen discharge driven by a nanosecond pulse power source. To assess whether the production of the metastable state N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) can be efficiently enhanced in a nanosecond pulsed discharge, the evolutions of metastable state N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) density and electron energy distribution function have been examined in detail. The simulation results indicate that the ultra short pulse can modulate the electron energy effectively: during the early pulse-on time, high energy electrons give rise to quick electron avalanche and rapid growth of the metastable state N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) density. It is estimated that for a single pulse with amplitude of -9 kV and pulse width 30 ns, the metastable state N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) density can achieve a value in the order of 10{sup 9} cm{sup -3}. The N{sub 2}(A{sup 3}{Sigma}{sub u}{sup +}) density at such a value could be easily detected by laser-based experimental methods.

Reducción de gasto energético eléctrico usando seis sigma

OpenAIRE

Morato Orozco, Juan Sebastián

2009-01-01

The application of Six Sigma to the models of energy management is vital because it brings a continuous improvement, optimizes the efficient consumption of energy and strengthens the conservation culture. This article shows an example of the application of the Six Sigma methodology in the energy management models used for the “Reduction of Energy Waste” in the Sumicol-Corona industrial park in Sabaneta, Antioquia. La aplicación de Seis Sigma a los modelos de gestión energética ...

A 8X Oversampling Ratio, 14bit, 5-MSamples/s Cascade 3-1 Sigma-delta Modulator

Directory of Open Access Journals (Sweden)

Y. Yin

2005-01-01

Full Text Available A 14-b, 5-MHz output-rate cascaded 3-1 sigma-delta analog-to-digital converters (ADC has been developed for broadband communication applications, and a novel 4th-order noise-shaping is obtained by using the proposed architecture. At a low oversampling ratio (OSR of 8, the ADC achieves 91.5dB signal-to-quantization ratio (SQNR, in contrast to 71.8dB of traditional 2-1-1 cascaded sigma-delta ADC in 2.5-MHz bandwidth and over 80dB signal-to-noise and distortion (SINAD even under assumptions of awful circuit non-idealities and opamp non-linearity. The proposed architecture can potentially operates at much more high frequencies with scaled IC technology, to expand the analog-to-digital conversion rate for high-resolution applications.

Neuroprotective targets through which 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79), a sigma receptor ligand, mitigates the effects of methamphetamine in vitro

Science.gov (United States)

Kaushal, Nidhi; Robson, Matthew J.; Rosen, Abagail; McCurdy, Christopher R.; Matsumoto, Rae R.

2014-01-01

Exposure to high or repeated doses of methamphetamine can cause hyperthermia and neurotoxicity, which are thought to increase the risk of developing a variety of neurological conditions. Sigma receptor antagonism can prevent methamphetamine-induced hyperthermia and neurotoxicity, but the underlying cellular targets through which the neuroprotection is conveyed remain unknown. Differentiated NG108-15 cells were thus used as a model system to begin elucidating the neuroprotective mechanisms targeted by sigma receptor antagonists to mitigate the effects of methamphetamine. In differentiated NG108-15 cells, methamphetamine caused the generation of reactive oxygen/nitrogen species, an increase in PERK-mediated endoplasmic reticulum stress and the activation of caspase-3, -8 and -9, ultimately resulting in apoptosis at micromolar concentrations, and necrotic cell death at higher concentrations. The sigma receptor antagonist, 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79), attenuated methamphetamine-induced increases in reactive oxygen/nitrogen species, activation of caspase-3,-8 and-9 and accompanying cellular toxicity. In contrast, 1,3-di(2-tolyl)-guanidine (DTG), a sigma receptor agonist, shifted the dose response curve of methamphetamine-induced cell death towards the left. To probe the effect of temperature on neurotoxicity, NG108-15 cells maintained at an elevated temperature (40 °C) exhibited a significant and synergistic increase in cell death in response to methamphetamine, compared to cells maintained at a normal cell culture temperature (37 °C). SN79 attenuated the enhanced cell death observed in the methamphetamine-treated cells at 40 °C. Together, the data demonstrate that SN79 reduces methamphetamine-induced reactive oxygen/nitrogen species generation and caspase activation, thereby conveying neuroprotective effects against methamphetamine under regular and elevated temperature conditions. PMID:24380829

The fourth-order non-linear sigma models and asymptotic freedom in four dimensions

International Nuclear Information System (INIS)

Buchbinder, I.L.; Ketov, S.V.

1991-01-01

Starting with the most general Lagrangian of the fourth-order non-linear sigma model in four space-time dimensions, we calculate the one-loop, on-shell ultra-violet-divergent part of the effective action. The formalism is based on the background field method and the generalised Schwinger-De Witt technique. The multiplicatively renormalisable case is investigated in some detail. The renormalisation group equations are obtained, and the conditions for a realisation of asymptotic freedom are considered. (orig.)

Synthesis and evaluation of fluorine-18-labeled SA4503 as a selective sigma1 receptor ligand for positron emission tomography

International Nuclear Information System (INIS)

Kawamura, Kazunori; Tsukada, Hideo; Shiba, Kazuhiro; Tsuji, Chieko; Harada, Norihiro; Kimura, Yuichi; Ishiwata, Kiichi

2007-01-01

The [ 18 F]fluoromethyl analog of the sigma 1 selective ligand 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) ([ 18 F]FM-SA4503) was prepared and its potential evaluated for the in vivo measurement of sigma 1 receptors with positron emission tomography (PET). FM-SA4503 had selective affinity for the sigma 1 receptor ( K i for sigma 1 receptor, 6.4 nM; K i for sigma 2 receptor, 250 nM) that was compatible with the affinity of SA4503 ( K i for sigma 1 receptor, 4.4 nM; K i for sigma 2 receptor, 242 nM). [ 18 F]FM-SA4503 was synthesized by 18 F-fluoromethylation of O-demethyl SA4503 in the radiochemical yield of 2.9-16.6% at the end of bombardment with a specific activity of 37.8-283 TBq/mmol at the end of synthesis. In mice, the uptake of [ 18 F]FM-SA4503 in the brain was gradually increased for 30 min after injection, and then decreased. In the blocking study, brain uptake was significantly decreased by co-injection of haloperidol to 32% of control, and FM-SA4503 to 52% of control. In PET study of the monkey brain, high uptake was found in the cerebral cortex, thalamus and striatum. The radioactivity level of [ 18 F]FM-SA4503 in the brain regions gradually increased over a period of 120 min after injection, followed by a stable plateau phase until 180 min after injection. In pretreatment with haloperidol measurement of the monkey brain, the radioactivity level was 22-32% and 11-25% of the baseline at 60 and 180 min, respectively, after injection, suggesting high receptor-specific binding. [ 18 F]FM-SA4503 showed specific binding to sigma 1 receptors in mice and monkeys; therefore, [ 18 F]FM-SA4503 has the potential for mapping sigma 1 receptors in the brain

Nucleon mass and sigma term from lattice QCD with two light fermion flavors

Energy Technology Data Exchange (ETDEWEB)

Bali, G.S.; Bruns, P.C.; Collins, S. [Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)

2012-06-15

We analyze N{sub f}=2 nucleon mass data with respect to their dependence on the pion mass down to m{sub {pi}}=157 MeV and compare it with predictions from covariant baryon chiral perturbation theory (BChPT). A novel feature of our approach is that we fit the nucleon mass data simultaneously with the directly obtained pion-nucleon {sigma}-term. Our lattice data below m{sub {pi}}=435 MeV is well described by O(p{sup 4}) BChPT and we find {sigma} 37(8)(6)MeV for the {sigma}-term at the physical point. Using the nucleon mass to set the scale we obtain a Sommer parameter of r{sub 0}=0.501(10)(11) fm. (orig.)

Six Sigma in Education

Science.gov (United States)

LeMahieu, Paul G.; Nordstrum, Lee E.; Cudney, Elizabeth A.

2017-01-01

Purpose: This paper is one of seven in this volume that aims to elaborate different approaches to quality improvement in education. It delineates a methodology called Six Sigma. Design/methodology/approach: The paper presents the origins, theoretical foundations, core principles and a case study demonstrating an application of Six Sigma in a…

sigma receptor ligands attenuate N-methyl-D-aspartate cytotoxicity in dopaminergic neurons of mesencephalic slice cultures.

Science.gov (United States)

Shimazu, S; Katsuki, H; Takenaka, C; Tomita, M; Kume, T; Kaneko, S; Akaike, A

2000-01-28

We investigated the potential neuroprotective effects of several sigma receptor ligands in organotypic midbrain slice cultures as an excitotoxicity model system. When challenged with 100-microM N-methyl-D-aspartate (NMDA) for 24 h, dopaminergic neurons in midbrain slice cultures degenerated, and this was prevented by (5R, 10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]-cyclohepten-5, 10-imine (MK-801; 1-10 microM). Concomitant application of ifenprodil (1-10 microM) or haloperidol (1-10 microM), both of which are high-affinity sigma receptor ligands, significantly attenuated the neurotoxicity of 100 microM NMDA. The sigma(1) receptor-selective ligand (+)-N-allylnormetazocine ((+)-SKF 10047; 1-10 microM) was also effective in attenuating the toxicity of NMDA. The effect of R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane hydrochloride ((-)-PPAP), a sigma receptor ligand with negligible affinity for the phencyclidine site of NMDA receptors, was also examined. (-)-PPAP (3-100 microM) caused a concentration-dependent reduction of NMDA cytotoxicity, with significant protection at concentrations of 30 and 100 microM. In contrast, (+)-SKF 10047 (10 microM) and (-)-PPAP (100 microM) showed no protective effects against cell death induced by the Ca(2+) ionophore ionomycin (1-3 microM). These results indicate that sigma receptor ligands attenuate the cytotoxic effects of NMDA on midbrain dopaminergic neurons, possibly via inhibition of NMDA receptor functions.

STELLAR CORONAE, SOLAR FLARES: A DETAILED COMPARISON OF {sigma} GEM, HR 1099, AND THE SUN IN HIGH-RESOLUTION X-RAYS

Energy Technology Data Exchange (ETDEWEB)

Huenemoerder, David P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Phillips, Kenneth J. H. [Visiting Scientist, Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Sylwester, Janusz; Sylwester, Barbara, E-mail: dph@space.mit.edu, E-mail: kennethjhphillips@yahoo.com, E-mail: js@cbk.pan.wroc.pl, E-mail: bs@cbk.pan.wroc.pl [Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland)

2013-05-10

The Chandra High Energy Transmission Grating Spectrometer (HETG) spectra of the coronally active binary stars {sigma} Gem and HR 1099 are among the highest fluence observations for such systems taken at high spectral resolution in X-rays with this instrument. This allows us to compare their properties in detail to solar flare spectra obtained with the Russian CORONAS-F spacecraft's RESIK instrument at similar resolution in an overlapping bandpass. Here we emphasize the detailed comparisons of the 3.3-6.1 A region (including emission from highly ionized S, Si, Ar, and K) from solar flare spectra to the corresponding {sigma} Gem and HR 1099 spectra. We also model the larger wavelength range of the HETG, from 1.7 to 25 A - having emission lines from Fe, Ca, Ar, Si, Al, Mg, Ne, O, and N-to determine coronal temperatures and abundances. {sigma} Gem is a single-lined coronally active long-period binary which has a very hot corona. HR 1099 is a similar, but shorter period, double-lined system. With very deep HETG exposures we can even study emission from some of the weaker species, such as K, Na, and Al, which are important since they have the lowest first ionization potentials, a parameter well known to be correlated with elemental fractionation in the solar corona. The solar flare temperatures reach Almost-Equal-To 20 MK, comparable to the {sigma} Gem and HR 1099 coronae. During the Chandra exposures, {sigma} Gem was slowly decaying from a flare and its spectrum is well characterized by a collisional ionization equilibrium plasma with a broad temperature distribution ranging from 2 to 60 MK, peaking near 25 MK, but with substantial emission from 50 MK plasma. We have detected K XVIII and Na XI emission which allow us to set limits on their abundances. HR 1099 was also quite variable in X-rays, also in a flare state, but had no detectable K XVIII. These measurements provide new comparisons of solar and stellar coronal abundances, especially at the lowest first

Defect and electrical transport properties of Nb-doped SrTiO₃

DEFF Research Database (Denmark)

Blennow Tullmar, Peter; Hagen, Anke; Kammer Hansen, Kent

2008-01-01

analyzed with SEM, XRD, TGA, and XANES. The electrical conductivity of Nb-doped strontium titanate (Sr0.94Ti0.9Nb0.1O3 - sintered in 9% H-2/N-2 at 1400 degrees C for 12 h) decreased with increasing temperature and showed a phonon scattering conduction mechanism with (sigma>120 S/cm at 1000 degrees C (in 9...

EVIDENCE FOR LOW BLACK HOLE SPIN AND PHYSICALLY MOTIVATED ACCRETION MODELS FROM MILLIMETER-VLBI OBSERVATIONS OF SAGITTARIUS A*

Energy Technology Data Exchange (ETDEWEB)

Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Fish, Vincent L; Doeleman, Sheperd S [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Loeb, Abraham [Institute for Theory and Computation, Harvard University, Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-07-10

Millimeter very long baseline interferometry (mm-VLBI) provides the novel capacity to probe the emission region of a handful of supermassive black holes on sub-horizon scales. For Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, this provides access to the region in the immediate vicinity of the horizon. Broderick et al. have already shown that by leveraging spectral and polarization information as well as accretion theory, it is possible to extract accretion-model parameters (including black hole spin) from mm-VLBI experiments containing only a handful of telescopes. Here we repeat this analysis with the most recent mm-VLBI data, considering a class of aligned, radiatively inefficient accretion flow (RIAF) models. We find that the combined data set rules out symmetric models for Sgr A*'s flux distribution at the 3.9{sigma} level, strongly favoring length-to-width ratios of roughly 2.4:1. More importantly, we find that physically motivated accretion flow models provide a significantly better fit to the mm-VLBI observations than phenomenological models, at the 2.9{sigma} level. This implies that not only is mm-VLBI presently capable of distinguishing between potential physical models for Sgr A*'s emission, but further that it is sensitive to the strong gravitational lensing associated with the propagation of photons near the black hole. Based upon this analysis we find that the most probable magnitude, viewing angle, and position angle for the black hole spin are a = 0.0{sup +0.64+0.86}, {theta}=68{sup o+5o+9o}{sub -20}{sup o}{sub -28}{sup o}, and {xi}=-52{sup o+17o+33o}{sub -15}{sup o}{sub -24}{sup o} east of north, where the errors quoted are the 1{sigma} and 2{sigma} uncertainties.

Use of the Six Sigma by the 500 Largent Companies in Portugal

OpenAIRE

Mendes da Conceição, Ana Cristina; Martins Ferreira Major, Maria João

2011-01-01

The Six Sigma had its genesis in big industrial companies that have implemented it as a tool for reducing defects. The initial success encouraged its application in other areas and we see today successful implementation in other sectors such as services, and within their own organizations in other areas beyond production, setting; this has contributed to Six Sigma being recognized as a new management model. In order to determine the extent to which Six Sigma is present in Portuguese companies...

Bose-Einstein condensation and chiral phase transition in linear sigma model

International Nuclear Information System (INIS)

Shu Song; Li Jiarong

2005-01-01

With the linear sigma model, we have studied Bose-Einstein condensation and the chiral phase transition in the chiral limit for an interacting pion system. A μ-T phase diagram including these two phenomena is presented. It is found that the phase plane has been divided into three areas: the Bose-Einstein condensation area, the chiral symmetry broken phase area and the chiral symmetry restored phase area. Bose-Einstein condensation can occur either from the chiral symmetry broken phase or from the restored phase. We show that the onset of the chiral phase transition is restricted in the area where there is no Bose-Einstein condensation

Quantum non-local charges and absence of particle production in the two-dimensional non-linear sigma-model

International Nuclear Information System (INIS)

Luescher, M.

1977-12-01

Conserved non-local charges are shown to exist in the quantum non-linear sigma-model by a non-perturbative method. They imply the absence of particle production and the 'factorization equations' for the two particle S-matrix, which can then be calculated explicitly. (Auth.)

Labeling by [3H]1,3-di(2-tolyl)guanidine of two high affinity binding sites in guinea pig brain: Evidence for allosteric regulation by calcium channel antagonists and pseudoallosteric modulation by sigma ligands

International Nuclear Information System (INIS)

Rothman, R.B.; Reid, A.; Mahboubi, A.; Kim, C.H.; De Costa, B.R.; Jacobson, A.E.; Rice, K.C.

1991-01-01

Equilibrium binding studies with the sigma receptor ligand [ 3 H]1,3-di(2-tolyl)guanidine ([ 3 H]DTG) demonstrated two high affinity binding sites in membranes prepared from guinea pig brain. The apparent Kd values of DTG for sites 1 and 2 were 11.9 and 37.6 nM, respectively. The corresponding Bmax values were 1045 and 1423 fmol/mg of protein. Site 1 had high affinity for (+)-pentazocine, haloperidol, (R)-(+)-PPP, carbepentane, and other sigma ligands, suggesting a similarity with the dextromethorphan/sigma 1 binding site described by Musacchio et al. [Life Sci. 45:1721-1732 (1989)]. Site 2 had high affinity for DTG and haloperidol (Ki = 36.1 nM) and low affinity for most other sigma ligands. Kinetic experiments demonstrated that [ 3 H]DTG dissociated in a biphasic manner from both site 1 and site 2. DTG and haloperidol increased the dissociation rate of [ 3 H]DTG from site 1 and site 2, demonstrating the presence of pseudoallosteric interactions. Inorganic calcium channel blockers such as Cd2+ selectively increased the dissociation rate of [ 3 H]DTG from site 2, suggesting an association of this binding site with calcium channels

Commutative $C^*$-algebras and $\\sigma$-normal morphisms

OpenAIRE

de Jeu, Marcel

2003-01-01

We prove in an elementary fashion that the image of a commutative monotone $\\sigma$-complete $C^*$-algebra under a $\\sigma$-normal morphism is again monotone $\\sigma$-complete and give an application of this result in spectral theory.

Study of the defect structure of ''pure'' and doped nonstoichiometric CeO2

International Nuclear Information System (INIS)

Blumenthal, R.N.

1975-09-01

Electrical conductivity and thermogravimetric measurements were made on Ta 2 O 5 -doped nonstoichiometric CeO 2 (i.e. Ce/sub 1-y/Ta/sub y/O/sub 2-x/ ) as a function of temperature and oxygen partial pressure. Over a limited range of temperature and nonstoichiometry, the isothermal dependence of the electrical conductivity on nonstoichiometry may be described by the equation sigma = A + Bx, where A is the electronic conductivity associated with the electronic defects produced by doping CeO 2 with Ta 2 O 5 . The electronic conductivity resulting from the nonstoichiometric defect reaction O/sup x/ + 2Ce/sub Ce//sup x/ = V 0 + 2Ce'sub Ce/ + 1 / 2 O 2 (g) is equal to Bx. The ionic conductivity may be described by the relation sigma/sub i/ = B[y+x]eμ'/sub V 0 / exp (--E/sub i//kT), and the electronic conductivity by the isothermal expressions sigma/sub e/ proportional to P/sub O 2 //sup -1/4/ and sigma/sub e/ proportional to x; x less than 3 x 10 -2 . These results are consistent with defect models involving doubly ionized oxygen vacancies. An empirical expression (i.e. Δ anti H/sub O 2 / proportional to y/2 or z/4) was obtained relating the dependence of Δ anti H/sub O 2 / on the dopant concentration of lower valent foreign cations (e.g. y/2 for Ce/sub 1-y/M/sub y/O/sub 2-y-x/ and z/4 for Ce/sub 1-z/M/sub z/O/sub 2-z/2-x/ where M = Ca, Sr and M' = Y, La). (auth)

Synthesis and evaluation of fluorine-18-labeled SA4503 as a selective sigma{sub 1} receptor ligand for positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Kazunori [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan) and Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Niigata 951-8585 (Japan)]. E-mail: kawamurak@bri.niigata-u.ac.jp; Tsukada, Hideo [Central Research Laboratory, Hamamatsu Photonics, K.K., Hamamatsu, Shizuoka 434-8601 (Japan); Shiba, Kazuhiro [Advanced Science Research Center, Kanazawa University, Kanazawa, Ishikawa 920-8640 (Japan); Tsuji, Chieko [NARD Institute, Ltd., Amagasaki, Hyogo 660-0805 (Japan); Harada, Norihiro [Central Research Laboratory, Hamamatsu Photonics, K.K., Hamamatsu, Shizuoka 434-8601 (Japan); Kimura, Yuichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); Ishiwata, Kiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan)

2007-07-15

The [{sup 18}F]fluoromethyl analog of the sigma{sub 1} selective ligand 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) ([{sup 18}F]FM-SA4503) was prepared and its potential evaluated for the in vivo measurement of sigma{sub 1} receptors with positron emission tomography (PET). FM-SA4503 had selective affinity for the sigma{sub 1} receptor ( K {sub i} for sigma{sub 1} receptor, 6.4 nM; K {sub i} for sigma{sub 2} receptor, 250 nM) that was compatible with the affinity of SA4503 ( K {sub i} for sigma{sub 1} receptor, 4.4 nM; K {sub i} for sigma{sub 2} receptor, 242 nM). [{sup 18}F]FM-SA4503 was synthesized by {sup 18}F-fluoromethylation of O-demethyl SA4503 in the radiochemical yield of 2.9-16.6% at the end of bombardment with a specific activity of 37.8-283 TBq/mmol at the end of synthesis. In mice, the uptake of [{sup 18}F]FM-SA4503 in the brain was gradually increased for 30 min after injection, and then decreased. In the blocking study, brain uptake was significantly decreased by co-injection of haloperidol to 32% of control, and FM-SA4503 to 52% of control. In PET study of the monkey brain, high uptake was found in the cerebral cortex, thalamus and striatum. The radioactivity level of [{sup 18}F]FM-SA4503 in the brain regions gradually increased over a period of 120 min after injection, followed by a stable plateau phase until 180 min after injection. In pretreatment with haloperidol measurement of the monkey brain, the radioactivity level was 22-32% and 11-25% of the baseline at 60 and 180 min, respectively, after injection, suggesting high receptor-specific binding. [{sup 18}F]FM-SA4503 showed specific binding to sigma{sub 1} receptors in mice and monkeys; therefore, [{sup 18}F]FM-SA4503 has the potential for mapping sigma{sub 1} receptors in the brain.

SU-E-T-760: Tolerance Design for Site-Specific Range in Proton Patient QA Process Using the Six Sigma Model

International Nuclear Information System (INIS)

Lah, J; Shin, D; Kim, G

2015-01-01

Purpose: To show how tolerance design and tolerancing approaches can be used to predict and improve the site-specific range in patient QA process in implementing the Six Sigma. Methods: In this study, patient QA plans were selected according to 6 site-treatment groups: head &neck (94 cases), spine (76 cases), lung (89 cases), liver (53 cases), pancreas (55 cases), and prostate (121 cases), treated between 2007 and 2013. We evaluated a model of the Six Sigma that determines allowable deviations in design parameters and process variables in patient-specific QA, where possible, tolerance may be loosened, then customized if it necessary to meet the functional requirements. A Six Sigma problem-solving methodology is known as DMAIC phases, which are used stand for: Define a problem or improvement opportunity, Measure process performance, Analyze the process to determine the root causes of poor performance, Improve the process by fixing root causes, Control the improved process to hold the gains. Results: The process capability for patient-specific range QA is 0.65 with only ±1 mm of tolerance criteria. Our results suggested the tolerance level of ±2–3 mm for prostate and liver cases and ±5 mm for lung cases. We found that customized tolerance between calculated and measured range reduce that patient QA plan failure and almost all sites had failure rates less than 1%. The average QA time also improved from 2 hr to less than 1 hr for all including planning and converting process, depth-dose measurement and evaluation. Conclusion: The objective of tolerance design is to achieve optimization beyond that obtained through QA process improvement and statistical analysis function detailing to implement a Six Sigma capable design

SU-E-T-760: Tolerance Design for Site-Specific Range in Proton Patient QA Process Using the Six Sigma Model

Energy Technology Data Exchange (ETDEWEB)

Lah, J [Myongji Hospital, Goyang, Gyeonggi-do (Korea, Republic of); Shin, D [National Cancer Center, Goyang-si, Gyeonggi-do (Korea, Republic of); Kim, G [University of California, San Diego, La Jolla, CA (United States)

2015-06-15

Purpose: To show how tolerance design and tolerancing approaches can be used to predict and improve the site-specific range in patient QA process in implementing the Six Sigma. Methods: In this study, patient QA plans were selected according to 6 site-treatment groups: head &neck (94 cases), spine (76 cases), lung (89 cases), liver (53 cases), pancreas (55 cases), and prostate (121 cases), treated between 2007 and 2013. We evaluated a model of the Six Sigma that determines allowable deviations in design parameters and process variables in patient-specific QA, where possible, tolerance may be loosened, then customized if it necessary to meet the functional requirements. A Six Sigma problem-solving methodology is known as DMAIC phases, which are used stand for: Define a problem or improvement opportunity, Measure process performance, Analyze the process to determine the root causes of poor performance, Improve the process by fixing root causes, Control the improved process to hold the gains. Results: The process capability for patient-specific range QA is 0.65 with only ±1 mm of tolerance criteria. Our results suggested the tolerance level of ±2–3 mm for prostate and liver cases and ±5 mm for lung cases. We found that customized tolerance between calculated and measured range reduce that patient QA plan failure and almost all sites had failure rates less than 1%. The average QA time also improved from 2 hr to less than 1 hr for all including planning and converting process, depth-dose measurement and evaluation. Conclusion: The objective of tolerance design is to achieve optimization beyond that obtained through QA process improvement and statistical analysis function detailing to implement a Six Sigma capable design.

Lean Six Sigma in financial services

OpenAIRE

de Koning, H.; Does, R.J.M.M.; Bisgaard, S.

2008-01-01

Lean Thinking and Six Sigma are typically considered as separate approaches to process innovation, with complementary strengths. When combined as Lean Six Sigma, this approach provides a unified framework for systematically developing innovations. Lean Six Sigma can also bring about significant results and breakthrough improvements in financial services, as demonstrated with four case studies from Dutch multinational insurance companies. These cases demonstrate the importance of incremental i...

Proposta de um modelo de gestão da qualidade para micro e pequenas empresas integrando a estratégia seis sigma à NBR ISO 9001

OpenAIRE

Costa, Filipe Cunha Reges da

2009-01-01

Este trabalho tem como principal objetivo propor um modelo de Gestão da Qualidade para micro e pequenas empresas integrando os modelos de gestão: estratégia Seis Sigma e NBR ISO 9001:2000. É desenvolvida uma pesquisa exploratória para levantamento das informações técnicas e bibliográficas existentes sobre as duas propostas, com ênfase em sua integração. Em seguida, procede-se a uma pesquisa de opinião, por meio de questionário, realizada com 65 analistas/consultores de Sistemas de Gestão d...

Polymorphism of the Hereditary Sigma Virus in Natural Populations of DROSOPHILA MELANOGASTER.

Science.gov (United States)

Fleuriet, A

1980-06-01

Previous studies have shown that, in natural French populations of Drosophila melanogaster, 10 to 20% of the flies are infected by the noncontagious, hereditary rhabdovirus sigma responsible for CO(2) sensitivity. These populations are also polymorphic for two alleles [ref(2)P(o) and ref(2)P(p)] of a gene for resistance to the sigma virus. Evidence is given here that two viral genetic types, differing in their response to the ref(2)P(p) allele, are present in these populations of flies; the most common type is only slightly sensitive to the ref(2)P(p) allele.

Sigma beta decay

International Nuclear Information System (INIS)

Newman, D.E.

1975-01-01

Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

Labeling by ( sup 3 H)1,3-di(2-tolyl)guanidine of two high affinity binding sites in guinea pig brain: Evidence for allosteric regulation by calcium channel antagonists and pseudoallosteric modulation by sigma ligands

Energy Technology Data Exchange (ETDEWEB)

Rothman, R.B.; Reid, A.; Mahboubi, A.; Kim, C.H.; De Costa, B.R.; Jacobson, A.E.; Rice, K.C. (National Institute of Mental Health, Bethesda, MD (USA))

1991-02-01

Equilibrium binding studies with the sigma receptor ligand ({sup 3}H)1,3-di(2-tolyl)guanidine (({sup 3}H)DTG) demonstrated two high affinity binding sites in membranes prepared from guinea pig brain. The apparent Kd values of DTG for sites 1 and 2 were 11.9 and 37.6 nM, respectively. The corresponding Bmax values were 1045 and 1423 fmol/mg of protein. Site 1 had high affinity for (+)-pentazocine, haloperidol, (R)-(+)-PPP, carbepentane, and other sigma ligands, suggesting a similarity with the dextromethorphan/sigma 1 binding site described by Musacchio et al. (Life Sci. 45:1721-1732 (1989)). Site 2 had high affinity for DTG and haloperidol (Ki = 36.1 nM) and low affinity for most other sigma ligands. Kinetic experiments demonstrated that ({sup 3}H)DTG dissociated in a biphasic manner from both site 1 and site 2. DTG and haloperidol increased the dissociation rate of ({sup 3}H)DTG from site 1 and site 2, demonstrating the presence of pseudoallosteric interactions. Inorganic calcium channel blockers such as Cd2+ selectively increased the dissociation rate of ({sup 3}H)DTG from site 2, suggesting an association of this binding site with calcium channels.

Study of Sigma /sup +or-/(1385) inclusive production in K/sup -/p interactions at 42 GeV/c

CERN Document Server

Barreiro, F; Blokzijl, R; Engelen, J J; Ganguli, S N; Gavillet, P; Hemingway, R J; Kittel, E W; Kluyver, J C; Shephard, W D; Wolters, G F

1977-01-01

Properties of Sigma /sup +or-/(1385) inclusively produced in 4.2 GeV/c K/sup -/p interactions are studied. Inclusive cross sections are presented together with differential cross sections as functions of x and p/sub t//sup 2/ for both Sigma /sup +/(1385) and Sigma /sup - /(1385). The complete density matrix for Sigma /sup +/(1385) production at small momentum transfer is studied as a function of t and of recoil mass MM/sup 2/. Substantial agreement with the predictions of the additive quark model is found. The Sigma /sup + /(1385) production in the target fragmentation region is studied in the framework of the triple-Regge model. (17 refs).

Lysosomal membrane permeabilization is an early event in Sigma-2 receptor ligand mediated cell death in pancreatic cancer.

Science.gov (United States)

Hornick, John R; Vangveravong, Suwanna; Spitzer, Dirk; Abate, Carmen; Berardi, Francesco; Goedegebuure, Peter; Mach, Robert H; Hawkins, William G

2012-05-02

Sigma-2 receptor ligands have been studied for treatment of pancreatic cancer because they are preferentially internalized by proliferating cells and induce apoptosis. This mechanism of apoptosis is poorly understood, with varying reports of caspase-3 dependence. We evaluated multiple sigma-2 receptor ligands in this study, each shown to decrease tumor burden in preclinical models of human pancreatic cancer. Fluorescently labeled sigma-2 receptor ligands of two classes (derivatives of SW43 and PB282) localize to cell membrane components in Bxpc3 and Aspc1 pancreatic cancer cells and accumulate in lysosomes. We found that interactions in the lysosome are critical for cell death following sigma-2 ligand treatment because selective inhibition of a protective lysosomal membrane glycoprotein, LAMP1, with shRNA greatly reduced the viability of cells following treatment. Sigma-2 ligands induced lysosomal membrane permeabilization (LMP) and protease translocation triggering downstream effectors of apoptosis. Subsequently, cellular oxidative stress was greatly increased following treatment with SW43, and the hydrophilic antioxidant N-acetylcysteine (NAC) gave greater protection against this than a lipophilic antioxidant, α-tocopherol (α-toco). Conversely, PB282-mediated cytotoxicity relied less on cellular oxidation, even though α-toco did provide protection from this ligand. In addition, we found that caspase-3 induction was not as significantly inhibited by cathepsin inhibitors as by antioxidants. Both NAC and α-toco protected against caspase-3 induction following PB282 treatment, while only NAC offered protection following SW43 treatment. The caspase-3 inhibitor DEVD-FMK offered significant protection from PB282, but not SW43. Sigma-2 ligand SW43 commits pancreatic cancer cells to death by a caspase-independent process involving LMP and oxidative stress which is protected from by NAC. PB282 however undergoes a caspase-dependent death following LMP protected by DEVD

THE LEAN AND SIX SIGMA SINERGY

Directory of Open Access Journals (Sweden)

Mirko Sokovic

2008-12-01

Full Text Available Many organizations, dealing with continuous improvement methods, have realized that Lean and Six Sigma methodologies complement each other. Lean manufacturing focuses on the remova l of waste so that all processes in the total system add value from the customers' perspectives. The main emphasis of Six Sigma is the application of statistical tools in a disciplined manner, which requires data-driven decision-making. The integration of Lean and Six Sigma provides a synergetic effect, a rapid process improvement strategy for attaining organizational goals. When separated, Lean manufacturing cannot bring a process under statistical control, and Six Sigma cannot dramatically improve cycle time or reduce invested capital. Together, synergistic qualities are created to maximize the potential for a process improvement. The paper deals with Lean and Six Sigma principles and approaches used in modern manufacturing for process improvements, and bring forward benefits that are gained when these two methodologies are integrated.

A contrast between DEMATEL-ANP and ANP methods for six sigma project selection: a case study in healthcare industry.

Science.gov (United States)

Ortíz, Miguel A; Felizzola, Heriberto A; Nieto Isaza, Santiago

2015-01-01

The project selection process is a crucial step for healthcare organizations at the moment of implementing six sigma programs in both administrative and caring processes. However, six-sigma project selection is often defined as a decision making process with interaction and feedback between criteria; so that it is necessary to explore different methods to help healthcare companies to determine the Six-sigma projects that provide the maximum benefits. This paper describes the application of both ANP (Analytic Network process) and DEMATEL (Decision Making trial and evaluation laboratory)-ANP in a public medical centre to establish the most suitable six sigma project and finally, these methods were compared to evaluate their performance in the decision making process. ANP and DEMATEL-ANP were used to evaluate 6 six sigma project alternatives under an evaluation model composed by 3 strategies, 4 criteria and 15 sub-criteria. Judgement matrixes were completed by the six sigma team whose participants worked in different departments of the medical centre. The improving of care opportunity in obstetric outpatients was elected as the most suitable six sigma project with a score of 0,117 as contribution to the organization goals. DEMATEL-ANP performed better at decision making process since it reduced the error probability due to interactions and feedback. ANP and DEMATEL-ANP effectively supported six sigma project selection processes, helping to create a complete framework that guarantees the prioritization of projects that provide maximum benefits to healthcare organizations. As DEMATEL- ANP performed better, it should be used by practitioners involved in decisions related to the implementation of six sigma programs in healthcare sector accompanied by the adequate identification of the evaluation criteria that support the decision making model. Thus, this comparative study contributes to choosing more effective approaches in this field. Suggestions of further work are also

The cognition-enhancing activity of E1R, a novel positive allosteric modulator of sigma-1 receptors

Science.gov (United States)

Zvejniece, L; Vavers, E; Svalbe, B; Vilskersts, R; Domracheva, I; Vorona, M; Veinberg, G; Misane, I; Stonans, I; Kalvinsh, I; Dambrova, M

2014-01-01

Background and Purpose Here, we describe the in vitro and in vivo effects of (4R,5S)-2-(5-methyl-2-oxo-4-phenyl-pyrrolidin-1-yl)-acetamide (E1R), a novel positive allosteric modulator of sigma-1 receptors. Experimental Approach E1R was tested for sigma receptor binding activity in a [3H](+)-pentazocine assay, in bradykinin (BK)-induced intracellular Ca2+ concentration ([Ca2+]i) assays and in an electrically stimulated rat vas deferens model. E1R's effects on cognitive function were tested using passive avoidance (PA) and Y-maze tests in mice. A selective sigma-1 receptor antagonist (NE-100), was used to study the involvement of the sigma-1 receptor in the effects of E1R. The open-field test was used to detect the effects of E1R on locomotion. Key Results Pretreatment with E1R enhanced the selective sigma-1 receptor agonist PRE-084's stimulating effect during a model study employing electrically stimulated rat vasa deferentia and an assay measuring the BK-induced [Ca2+]i increase. Pretreatment with E1R facilitated PA retention in a dose-related manner. Furthermore, E1R alleviated the scopolamine-induced cognitive impairment during the PA and Y-maze tests in mice. The in vivo and in vitro effects of E1R were blocked by treatment with the selective sigma-1 receptor antagonist NE-100. E1R did not affect locomotor activity. Conclusion and Implications E1R is a novel 4,5-disubstituted derivative of piracetam that enhances cognition and demonstrates efficacy against scopolamine-induced cholinergic dysfunction in mice. These effects are attributed to its positive modulatory action on the sigma-1 receptor and this activity may be relevant when developing new drugs for treating cognitive symptoms related to neurodegenerative diseases. PMID:24490863

Apparently noninvariant terms of nonlinear sigma models in lattice perturbation theory

International Nuclear Information System (INIS)

Harada, Koji; Hattori, Nozomu; Kubo, Hirofumi; Yamamoto, Yuki

2009-01-01

Apparently noninvariant terms (ANTs) that appear in loop diagrams for nonlinear sigma models are revisited in lattice perturbation theory. The calculations have been done mostly with dimensional regularization so far. In order to establish that the existence of ANTs is independent of the regularization scheme, and of the potential ambiguities in the definition of the Jacobian of the change of integration variables from group elements to 'pion' fields, we employ lattice regularization, in which everything (including the Jacobian) is well defined. We show explicitly that lattice perturbation theory produces ANTs in the four-point functions of the pion fields at one-loop and the Jacobian does not play an important role in generating ANTs.

Plastic Injection Quality Controlling Using the Lean Six Sigma and FMEA Method

Science.gov (United States)

Mansur, A.; Mu'alim; Sunaryo

2016-01-01

PT. Yogya Presisi Teknikatama Industri (PT. YPTI) is a mold, precision part, and plastic injection maker company. One of the obstacles faced by the company is the high level of nonconformity on its production results. The waste on production process can be identified and classified into four types, i.e.: a). during the process of injection molding machines, b). finishing and cutting processes, c). quality control process and d). the packaging process. The objectives of this research are minimizing the defective goods and reducing the waste using Lean Six Sigma and FMEA approaches, especially for Bush product. From the analysis result, defective types on Bush product can be classified into bubble, speckle, short shoot, sunken, sink mark, over-cut, flashing, and discolor. Based on the attributes data on Bush product, the DPMO score is 988.42 or the sigma level is 4.6, While the DPMO score on the variable data on each dimension i.e.: a). Slit width on the bottom side has DPMO score of 30119 (sigma level 3.37), b). Diameter of the circle on the top side has DPMO score of 392294 (sigma level 1.77), c). Product thickness on the top side has DPMO score of 70474 (sigma level 2.97), d). Product height has DPMO score of 82107 (sigma level 2.89), product thickness on the bottom side has DPMO score of 24448 (sigma level 3.47), and f). Diameter of the circle on the bottom side has DPMO score of 24448 (sigma level 3.47). The highest RPN score on the dominant types of product defects which needs improvement are the defective goods of bubble type has RPN score of 729, flashing and the molten material out on the heating channel has RPN score of 384, over cutting has RPN score of 324 and sink mark has RPN score of 270. The recommendations for improvement that can be given from this research are making checklist for maintenance and production monitoring, enhancing work supervision and inspection, as well as improving the environment and work stations.

Pure and entangled N=4 linear supermultiplets and their one-dimensional sigma-models

International Nuclear Information System (INIS)

Gonzales, Marcelo; Iga, Kevin; Khodaee, Sadi; Toppan, Francesco

2012-01-01

“Pure” homogeneous linear supermultiplets (minimal and non-minimal) of the N=4-extended one-dimensional supersymmetry algebra are classified. “Pure” means that they admit at least one graphical presentation (the corresponding graph/graphs are known as “Adinkras”). We further prove the existence of “entangled” linear supermultiplets which do not admit a graphical presentation, by constructing an explicit example of an entangled N=4 supermultiplet with field content (3, 8, 5). It interpolates between two inequivalent pure N=4 supermultiplets with the same field content. The one-dimensional N=4 sigma-model with a three-dimensional target based on the entangled supermultiplet is presented. The distinction between the notion of equivalence for pure supermultiplets and the notion of equivalence for their associated graphs (Adinkras) is discussed. Discrete properties such as “chirality” and “coloring” can discriminate different supermultiplets. The tools used in our classification include, among others, the notion of field content, connectivity symbol, commuting group, node choice group, and so on.

Excited scalar and pseudoscalar mesons in the extended linear sigma model

Energy Technology Data Exchange (ETDEWEB)

Parganlija, Denis [Technische Universitaet Wien, Institut fuer Theoretische Physik, Vienna (Austria); Giacosa, Francesco [Jan Kochanowski University, Institute of Physics, Kielce (Poland); Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany)

2017-07-15

We present an in-depth study of masses and decays of excited scalar and pseudoscalar anti qq states in the Extended Linear Sigma Model (eLSM). The model also contains ground-state scalar, pseudoscalar, vector and axial-vector mesons. The main objective is to study the consequences of the hypothesis that the f{sub 0}(1790) resonance, observed a decade ago by the BES Collaboration and recently by LHCb, represents an excited scalar quarkonium. In addition we also analyse the possibility that the new a{sub 0}(1950) resonance, observed recently by BABAR, may also be an excited scalar state. Both hypotheses receive justification in our approach although there appears to be some tension between the simultaneous interpretation of f{sub 0}(1790)/a{sub 0}(1950) and pseudoscalar mesons η(1295), π(1300), η(1440) and K(1460) as excited anti qq states. (orig.)

Six sigma for revenue retrieval.

Science.gov (United States)

Plonien, Cynthia

2013-01-01

Deficiencies in revenue retrieval due to failures in obtaining charges have contributed to a negative bottom line for numerous hospitals. Improving documentation practices through a Six Sigma process improvement initiative can minimize opportunities for errors through reviews and instill structure for compliance and consistency. Commitment to the Six Sigma principles with continuous monitoring of outcomes and constant communication of results to departments, management, and payers is a strong approach to reducing the financial impact of denials on an organization's revenues and expenses. Using Six Sigma tools can help improve the organization's financial performance not only for today, but also for health care's uncertain future.

Effect of phase interaction on catalytic CO oxidation over the SnO_2/Al_2O_3 model catalyst

International Nuclear Information System (INIS)

Chai, Shujing; Bai, Xueqin; Li, Jing; Liu, Cheng; Ding, Tong; Tian, Ye; Liu, Chang; Xian, Hui; Mi, Wenbo; Li, Xingang

2017-01-01

Highlights: • Activity for CO oxidation is greatly enhanced by interaction between SnO_2 and Al_2O_3. • Interaction between SnO_2 and Al_2O_3 phases can generate oxygen vacancies. • Oxygen vacancies play an import role for catalytic CO oxidation. • Sn"4"+ cations are the effective sites for catalytic CO oxidation. • Langmuir-Hinshelwood model is preferred for catalytic CO oxidation. - Abstract: We investigated the catalytic CO oxidation over the SnO_2/Al_2O_3 model catalysts. Our results show that interaction between the Al_2O_3 and SnO_2 phases results in the significantly improved catalytic activity because of the formation of the oxygen vacancies. The oxygen storage capacity of the SnO_2/Al_2O_3 catalyst prepared by the physically mixed method is nearly two times higher than that of the SnO_2, which probably results from the change of electron concentration on the interface of the SnO_2 and Al_2O_3 phases. Introducing water vapor to the feeding gas would a little decrease the activity of the catalysts, but the reaction rate could completely recover after removal of water vapor. The kinetics results suggest that the surface Sn"4"+ cations are effective CO adsorptive sites, and the surface adsorbed oxygen plays an important role upon CO oxidation. The reaction pathways upon the SnO_2-based catalysts for CO oxidation follow the Langmuir-Hinshelwood model.

$K^{\\pm}n$ forward dispersion relations and the KN$\\Sigma$ coupling constant

CERN Document Server

Baillon, Paul; Ferro-Luzzi, M; Jenni, Peter; Perreau, J M; Tripp, R D; Ypsilantis, Thomas; Déclais, Y; Séguinot, Jacques

1976-01-01

Recent measurements of the K/sup -/n forward scattering amplitude at 1.2, 1.4, 2.6 GeV/c are used in a once-subtracted dispersion relation to determine the value of the KN Sigma coupling constant. The result is g/sub Sigma //sup 2/=1.9+or-3.2, in agreement with the prediction of the SU(3) theory.

Potentiation of nerve growth factor-induced neurite outgrowth in PC12 cells by ifenprodil: the role of sigma-1 and IP3 receptors.

Directory of Open Access Journals (Sweden)

Tamaki Ishima

Full Text Available In addition to both the α1 adrenergic receptor and N-methyl-D-aspartate (NMDA receptor antagonists, ifenprodil binds to the sigma receptor subtypes 1 and 2. In this study, we examined the effects of ifenprodil on nerve growth factor (NGF-induced neurite outgrowth in PC12 cells. Ifenprodil significantly potentiated NGF-induced neurite outgrowth, in a concentration-dependent manner. In contrast, the α1 adrenergic receptor antagonist, prazosin and the NMDA receptor NR2B antagonist, Ro 25-6981 did not alter NGF-induced neurite outgrowth. Potentiation of NGF-induced neurite outgrowth mediated by ifenprodil was significantly antagonized by co-administration of the selective sigma-1 receptor antagonist, NE-100, but not the sigma-2 receptor antagonist, SM-21. Similarly, ifenprodil enhanced NGF-induced neurite outgrowth was again significantly reduced by the inositol 1,4,5-triphosphate (IP(3 receptor antagonists, xestospongin C and 2-aminoethoxydiphenyl borate (2-APB treatment. Furthermore, BAPTA-AM, a chelator of intracellular Ca(2+, blocked the effects of ifenprodil on NGF-induced neurite outgrowth, indicating the role of intracellular Ca(2+ in the neurite outgrowth. These findings suggest that activation at sigma-1 receptors and subsequent interaction with IP(3 receptors may mediate the pharmacological effects of ifenprodil on neurite outgrowth.

6 Sigma project advance

International Nuclear Information System (INIS)

2002-12-01

This book deals with 6 sigma project advance which introduces 6 sigma project in Changwon special steel, how is failure accepted? CTQ selection which is starting line, definition of performance standard, measurement system check on reliability of measurement data, check of process capacity for current level, establishment of target, optimal design and performance of application, practice of management system for maintain of improved result, CTQ selection, check of measurement system and practice of management system.

Lean sigma--will it work for healthcare?

Science.gov (United States)

Bahensky, James A; Roe, Janet; Bolton, Romy

2005-01-01

The manufacturing industry has been using Lean Sigma for years in pursuit of continuous improvement to obtain a competitive advantage. The objectives of these efforts are to use the Lean techniques for reducing cycle times and the Six Sigma concepts for reducing product defects. The Iowa Business Council with several advocates worked with the University of Iowa Hospital and Clinics (UIHC) and two other Iowa hospitals to determine whether Lean Sigma is adaptable in healthcare. A team of 15 people at UIHC used the Kaizen Breakthrough Methodology over a five-day period in an aggressive identification and elimination of non-value added activities in Radiology CT scanning. The results exceeded the initial project objectives and indicated that Lean Sigma is applicable in healthcare. Overall, the Lean Sigma project increased revenue by approximately $750,000 per year. The Kaizen process proved to be successful and interesting. Within three days, the team installed new work flow processes. This implementation-oriented approach is what differentiates Lean Sigma from other quality improvement processes.

Non Abelian T-duality in Gauged Linear Sigma Models

Science.gov (United States)

Bizet, Nana Cabo; Martínez-Merino, Aldo; Zayas, Leopoldo A. Pando; Santos-Silva, Roberto

2018-04-01

Abelian T-duality in Gauged Linear Sigma Models (GLSM) forms the basis of the physical understanding of Mirror Symmetry as presented by Hori and Vafa. We consider an alternative formulation of Abelian T-duality on GLSM's as a gauging of a global U(1) symmetry with the addition of appropriate Lagrange multipliers. For GLSMs with Abelian gauge groups and without superpotential we reproduce the dual models introduced by Hori and Vafa. We extend the construction to formulate non-Abelian T-duality on GLSMs with global non-Abelian symmetries. The equations of motion that lead to the dual model are obtained for a general group, they depend in general on semi-chiral superfields; for cases such as SU(2) they depend on twisted chiral superfields. We solve the equations of motion for an SU(2) gauged group with a choice of a particular Lie algebra direction of the vector superfield. This direction covers a non-Abelian sector that can be described by a family of Abelian dualities. The dual model Lagrangian depends on twisted chiral superfields and a twisted superpotential is generated. We explore some non-perturbative aspects by making an Ansatz for the instanton corrections in the dual theories. We verify that the effective potential for the U(1) field strength in a fixed configuration on the original theory matches the one of the dual theory. Imposing restrictions on the vector superfield, more general non-Abelian dual models are obtained. We analyze the dual models via the geometry of their susy vacua.

Z-contrast imaging of ordered structures in Pb(Mg1/3Nb2/3)O3 and Ba(Mg1/3Nb2/3)O3

International Nuclear Information System (INIS)

Yan, Y.; Pennycook, S.J.; Xu, Z.; Viehland, D.

1998-02-01

Lead-based cubic perovskites such as Pb(B 1/3 2+ B 2/3 5+ )O 3 (B 2+ Mg, Co, Ni, Zn; B 5+ = Nb, Ta) are relaxor ferroelectrics. Localized order and disorder often occur in materials of this type. In the Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) family, previous studies have proposed two models, space-charge and charge-balance models. In the first model, the ordered regions carry a net negative charge [Pb(Mg 1/2 Nb 1/2 )O 3 ], while in the second model it does not carry a net charge [Pb((Mg 2/3 Nb 1/3 ) 1/2 Nb 1/2 )O 3 ]. However, no direct evidence for these two models has appeared in the literature yet. In this paper the authors report the first direct observations of local ordering in undoped and La-doped Pb(Mg 1/3 Nb 2/3 )O 3 , using high-resolution Z-contrast imaging. Because the ordered structure in Ba(Mg 1/3 Nb 2/3 )O 3 is well known, the Z-contrast image from an ordered domain is used as a reference for this study

Guiding inpatient quality improvement: a systematic review of Lean and Six Sigma.

Science.gov (United States)

Glasgow, Justin M; Scott-Caziewell, Jill R; Kaboli, Peter J

2010-12-01

Two popular quality improvement (QI) approaches in health care are Lean and Six Sigma. Hospitals continue to adopt these QI approaches-or the hybrid Lean Sigma approach-with little knowledge on how well they produce sustainable improvements. A systematic literature review was conducted to determine whether Lean, Six Sigma, or Lean Sigma have been effectively used to create and sustain improvements in the acute care setting. Databases were searched for articles published in the health care, business, and engineering literatures. Study inclusion criteria required identification of a Six Sigma, Lean, or Lean Sigma project; QI efforts focused on hospitalized patients; descriptions of project improvements; and reported results. Depending on the quality of data reported, articles were classified as summary reports, pre-post observational studies, or time-series reports. Database searches identified 539 potential articles. After review of titles, abstracts, and full text, 47 articles met inclusion criteria--10 articles summarized multiple projects, 12 reported Lean projects, 20 reported Six Sigma projects, and 5 reported Lean Sigma projects. Generally, the studies provided limited data, with only 15 articles providing any sort of follow-up data; of the 15, only 3 report a follow-up period greater than two years. Lean, Six Sigma, and Lean Sigma as QI approaches can aid institutions in tackling a wide variety of problems encountered in acute care. However, the true impact of these approaches is difficult to judge, given that the lack of rigorous evaluation or clearly sustained improvements provides little evidence supporting broad adoption. There is still a need for future work that will improve the evidence base for understanding more about QI approaches and how to achieve sustainable improvement.

IMPROVING PERFORMANCE OF BISCUIT PRODUCTION PROCESS THROUGH LEAN SIX-SIGMA AT PT XYZ

Directory of Open Access Journals (Sweden)

Ahmad Mukti Almansur

2017-05-01

Full Text Available This research aims to analyze waste or loss using the 7-waste approach and value added/non value added activities in the production process at PT. XYZ. This research also aims to evaluate the production process capability and sigma values at PT. XYZ and used DMAIC technique (Define, Measure, Analysis, Improvement, and Control from Lean Six-sigma with an analysis using Failure Mode and Effect Analysis (FMEA. The results of the research obtained the values of Process Cycle Efficiency (PCE of 47.29%, CTQ (Critical to Quality and process capability value in the form of Cpm (Capability Index for each process stage and yield. Line-5 has DPMO (Defects per Million Opportunities value of 29,632,607 with a Sigma Score 3.39, and FMEA (Failure Mode and Effect Analysis analysis resulted in recommendations for improvement at each process stage.Keywords: process cycle efficiency, biscuit, lean six-sigma, CTQ, CpmABSTRAKPenelitian ini bertujuan melakukan analisis tingkat pemborosan (waste/loss dengan menggunakan pendekatan 7 waste dan value added/non value added activity dalam proses produksi di PT. XYZ. Selanjutnya, melakukan evaluasi terhadap nilai kapabilitas proses produksi dan nilai sigma di PT. XYZ. Penelitian ini menggunakan teknik DMAIC (Define, Measure, Analysis, Improvement, and Control dari Lean Six Sigma dengan Analisis menggunakan menggunakan alat Failure Mode and Effect Analysis (FMEA. Hasil Penelitian mendapati nilai Process Cycle Efficiency (PCE 47.29%, CTQ (Critical to Quality dan nilai kapabilitas proses berupa Cpm (Capability Index setiap tahapan proses dan Yield. Line-5 memiliki DPMO (Defects Per Million Opportunities sebesar 29632.607 dengan Sigma Score 3.39 Sigma, analisis FMEA(Failure Mode and Effect Analysis menghasilkan rekomendasi perbaikan di setiap tahapan proses.Kata kunci: process cycle efficiency, biskuit, lean six sigma, CTQ, Cpm

Does the HyperCP evidence for the decay Sigma+ -->pmu+mu- indicate a light pseudoscalar Higgs boson?

Science.gov (United States)

He, Xiao-Gang; Tandean, Jusak; Valencia, G

2007-02-23

The HyperCP Collaboration has observed three events for the decay Sigma+ -->p mu+mu- which may be interpreted as a new particle of mass 214.3 MeV. However, existing data from kaon and B-meson decays provide stringent constraints on the construction of models that support this interpretation. In this Letter we show that the "HyperCP particle" can be identified with the light pseudoscalar Higgs boson in the next-to-minimal supersymmetric standard model, the A10. In this model there are regions of parameter space where the A10 can satisfy all the existing constraints from kaon and B-meson decays and mediate Sigma+ -->p mu+mu- at a level consistent with the HyperCP observation.

Improving Self Service the Six Sigma Way at Newcastle University Library

Science.gov (United States)

Kumi, Susan; Morrow, John

2006-01-01

Purpose: To report on the collaborative project between Newcastle University Library and 3M which aimed to increase self-issue levels using six sigma methodology. Design/methodology/approach: The six-month long project is outlined and gives an insight into the process improvement methodology called six sigma. An explanation of why we ran the…

Topics in conformal invariance and generalized sigma models

International Nuclear Information System (INIS)

Bernardo, L.M.; Lawrence Berkeley National Lab., CA

1997-05-01

This thesis consists of two different parts, having in common the fact that in both, conformal invariance plays a central role. In the first part, the author derives conditions for conformal invariance, in the large N limit, and for the existence of an infinite number of commuting classical conserved quantities, in the Generalized Thirring Model. The treatment uses the bosonized version of the model. Two different approaches are used to derive conditions for conformal invariance: the background field method and the Hamiltonian method based on an operator algebra, and the agreement between them is established. The author constructs two infinite sets of non-local conserved charges, by specifying either periodic or open boundary conditions, and he finds the Poisson Bracket algebra satisfied by them. A free field representation of the algebra satisfied by the relevant dynamical variables of the model is also presented, and the structure of the stress tensor in terms of free fields (and free currents) is studied in detail. In the second part, the author proposes a new approach for deriving the string field equations from a general sigma model on the world sheet. This approach leads to an equation which combines some of the attractive features of both the renormalization group method and the covariant beta function treatment of the massless excitations. It has the advantage of being covariant under a very general set of both local and non-local transformations in the field space. The author applies it to the tachyon, massless and first massive level, and shows that the resulting field equations reproduce the correct spectrum of a left-right symmetric closed bosonic string

Sigma metric analysis for performance of creatinine with fresh frozen serum.

Science.gov (United States)

Kang, Fengfeng; Zhang, Chuanbao; Wang, Wei; Wang, Zhiguo

2016-01-01

Six sigma provides an objective and quantitative methodology to describe the laboratory testing performance. In this study, we conducted a national trueness verification scheme with fresh frozen serum (FFS) for serum creatinine to evaluate its performance in China. Two different concentration levels of FFS, targeted with reference method, were sent to 98 laboratories in China. Imprecision and bias of the measurement procedure were calculated for each participant to further evaluate the sigma value. Quality goal index (QGI) analysis was used to investigate the reason of unacceptable performance for laboratories with σ high concentration of creatinine had preferable sigma values. For the enzymatic method, 7.0% (5/71) to 45.1% (32/71) of the laboratories need to improve their measurement procedures (σ 1.2). Only 3.1-5.3% of the laboratories should improve both of the precision and trueness. Sigma metric analysis of the serum creatinine assays is disappointing, which was mainly due to the unacceptable analytical bias according to the QGI analysis. Further effort is needed to enhance the trueness of the creatinine measurement.

Sigma factors and promoters in Corynebacterium glutamicum

Czech Academy of Sciences Publication Activity Database

Pátek, Miroslav; Nešvera, Jan

2011-01-01

Roč. 154, 2-3 (2011), s. 101-113 ISSN 0168-1656 R&D Projects: GA ČR GC204/09/J015 Institutional research plan: CEZ:AV0Z50200510 Keywords : Corynebacterium glutamicum * Sigma factors * Promoters Subject RIV: EE - Microbiology, Virology Impact factor: 3.045, year: 2011

The microscopic model of BiFeO3

Science.gov (United States)

Fishman, R. S.

2018-05-01

Many years and great effort have been spent constructing the microscopic model for the room temperature multiferroic BiFeO3. However, earlier models implicitly assumed that the cycloidal wavevector q was confined to one of the three-fold symmetric axes in the hexagonal plane normal to the electric polarization. Because recent measurements indicate that q can be rotated by a magnetic field, it is essential to properly treat the anisotropy that confines q at low fields. We propose that the anisotropy energy -K3S6sin6 θ cos 6 ϕ confines the wavevectors q to the three-fold axis ϕ = 0 and ± 2 π / 3 within the hexagonal plane with θ = π / 2 .

First observation of the production and decay of the Sigma /sub c//sup +/

CERN Document Server

Calicchio, M; Azemoon, T; Baker, N J; Bartley, J H; Baton, Jean-Pierre; Belusevic, R; Bertrand, D; Bingham, H H; Brisson, V; Bullock, F W; Colley, D C; Cooper, A M; Erriquez, O; Fogli-Muciaccia, M T; François, T; Gerbier, G; Guy, J G; Iori, M; Jones, G T; Kochowski, Claude; Leutz, H; Marage, P; Michette, A G; Moreels, J; Natali, S; Neveu, M; Nuzzo, S; O'Neale, S W; Petiau, P; Romano, F; Ruggieri, F; Sacton, J; Sewell, S J; Tyndel, M; Van Doninck, W K; Vander Velde-Wilquet, C; Venus, W; Votruba, M F; Wenninger, H; Wilquet, G

1980-01-01

An event with the decay chain Sigma /sub c//sup +/ to Lambda /sub c //sup +/+ pi /sup 0/, Lambda /sub c//sup +/ to K/sup -/+p+ pi /sup +/, has been observed in an exposure of BEBC, equipped with a track sensitive target, to the wide band neutrino beam from the SPS at CERN. The event has a unique three constraint kinematic fit to the Delta S=- Delta Q reaction nu +p to mu /sup -/+p+K/sup -/+ pi /sup +/+ pi /sup + /+ pi /sup 0/ with both gammas from the pi /sup 0/ decay detected. The proton and other final state particles are identified. The masses are M( Lambda /sub c//sup +/)=2290+or-3 MeV/c/sup 2/, M( Sigma /sub c//sup +/)=2457+or-4 MeV/c/sup 2/ and M( Sigma /sub c//sup +/)-M( Lambda /sub c//sup +/)=168+or-3 MeV/c/sup 2/. Including other data one obtains M( Sigma /sub c//sup ++/)-M( Sigma /sub c//sup +/)=0+or-4 Mev/c/sup 2/. (7 refs).

Application of Six Sigma Robust Optimization in Sheet Metal Forming

International Nuclear Information System (INIS)

Li, Y.Q.; Cui, Z.S.; Ruan, X.Y.; Zhang, D.J.

2005-01-01

Numerical simulation technology and optimization method have been applied in sheet metal forming process to improve design quality and shorten design cycle. While the existence of fluctuation in design variables or operation condition has great influence on the quality. In addition to that, iterative solution in numerical simulation and optimization usually take huge computational time or endure expensive experiment cost In order to eliminate effect of perturbations in design and improve design efficiency, a CAE-based six sigma robust design method is developed in this paper. In the six sigma procedure for sheet metal forming, statistical technology and dual response surface approximate model as well as algorithm of 'Design for Six Sigma (DFSS)' are integrated together to perform reliability optimization and robust improvement. A deep drawing process of a rectangular cup is taken as an example to illustrate the method. The optimization solutions show that the proposed optimization procedure not only improves significantly the reliability and robustness of the forming quality, but also increases optimization efficiency with approximate model

Molecular imaging of {sigma} receptors: synthesis and evaluation of the potent {sigma}{sub 1} selective radioligand [{sup 18}F]fluspidine

Energy Technology Data Exchange (ETDEWEB)

Fischer, Steffen; Hiller, Achim; Deuther-Conrad, Winnie; Scheunemann, Matthias; Steinbach, Joerg; Brust, Peter [Institute of Radiopharmacy, Forschungszentrum Dresden-Rossendorf, Research Site Leipzig, Interdisciplinary Isotope Research, Leipzig (Germany); Wiese, Christian; Grosse Maestrup, Eva; Schepmann, Dirk; Wuensch, Bernhard [Institut fuer Pharmazeutische und Medizinische Chemie der Westfaelischen Wilhelms-Universitaet Muenster, Muenster (Germany)

2011-03-15

Neuroimaging of {sigma}{sub 1} receptors in the human brain has been proposed for the investigation of the pathophysiology of neurodegenerative and psychiatric diseases. However, there is a lack of suitable {sup 18}F-labelled PET radioligands for that purpose. The selective {sigma}{sub 1} receptor ligand [{sup 18}F]fluspidine (1'-benzyl-3-(2-[{sup 18}F]fluoroethyl)-3H-spiro[[2]benzofuran-1,4'-piperidine]) was synthesized by nucleophilic {sup 18}F{sup -} substitution of the tosyl precursor. In vitro receptor binding affinity and selectivity were assessed by radioligand competition in tissue homogenate and autoradiographic approaches. In female CD-1 mice, in vivo properties of [{sup 18}F]fluspidine were evaluated by ex vivo brain section imaging and organ distribution of intravenously administered radiotracer. Target specificity was validated by organ distribution of [{sup 18}F]fluspidine after treatment with 1 mg/kg i.p. of the {sigma} receptor antagonist haloperidol or the emopamil binding protein (EBP) inhibitor tamoxifen. In vitro metabolic stability and in vivo metabolism were investigated by LC-MS{sup n} and radio-HPLC analysis. [{sup 18}F]Fluspidine was obtained with a radiochemical yield of 35-45%, a radiochemical purity of {>=} 99.6% and a specific activity of 150-350 GBq/{mu}mol (n = 6) within a total synthesis time of 90-120 min. In vitro, fluspidine bound specifically and with high affinity to {sigma}{sub 1} receptors (K{sub i} = 0.59 nM). In mice, [{sup 18}F]fluspidine rapidly accumulated in brain with uptake values of 3.9 and 4.7%ID/g and brain to blood ratios of 7 and 13 at 5 and 30 min after intravenous application of the radiotracer, respectively. By ex vivo autoradiography of brain slices, resemblance between binding site occupancy of [{sup 18}F]fluspidine and the expression of {sigma}{sub 1} receptors was shown. The radiotracer uptake in the brain as well as in peripheral {sigma}{sub 1} receptor expressing organs was significantly

Bulanık Analitik Hiyerarşi Süreci ile Uygun Altı Sigma Metodolojisinin Seçimi(The Selection of Appropriate Six Sigma Methodology by Using Fuzzy Analytical Hierarchy Process

Directory of Open Access Journals (Sweden)

Çiğdem SOFYALIOĞLU

2009-01-01

Full Text Available Six sigma is considered as a business strategy that depends on the continuous improvement approach that tries to eliminate the process variability and aims to decrease the scrap in business processes by using statistical tools and techniques. In this study, first the differences between Six Sigma Improvement Model and Design for Six Sigma will be given and then the proper methodology for the business in order to achieve its goals will be determined by using fuzzy AHP which is one of the multicriteria decision making techniques.

3D modeling of effects of increased oxygenation and activity concentration in tumors treated with radionuclides and antiangiogenic drugs

Energy Technology Data Exchange (ETDEWEB)

Lagerloef, Jakob H.; Kindblom, Jon; Bernhardt, Peter [Department of Radiation Physics, Goeteborg University, Goeteborg 41345 (Sweden); Department of Oncology, Sahlgrenska University Hospital, Goeteborg 41345 (Sweden); Department of Radiation Physics, Goeteborg University, Goeteborg, Sweden and Department of Nuclear Medicine, Sahlgrenska University Hospital, Goeteborg 41345 (Sweden)

2011-08-15

Purpose: Formation of new blood vessels (angiogenesis) in response to hypoxia is a fundamental event in the process of tumor growth and metastatic dissemination. However, abnormalities in tumor neovasculature often induce increased interstitial pressure (IP) and further reduce oxygenation (pO{sub 2}) of tumor cells. In radiotherapy, well-oxygenated tumors favor treatment. Antiangiogenic drugs may lower IP in the tumor, improving perfusion, pO{sub 2} and drug uptake, by reducing the number of malfunctioning vessels in the tissue. This study aims to create a model for quantifying the effects of altered pO{sub 2}-distribution due to antiangiogenic treatment in combination with radionuclide therapy. Methods: Based on experimental data, describing the effects of antiangiogenic agents on oxygenation of GlioblastomaMultiforme (GBM), a single cell based 3D model, including 10{sup 10} tumor cells, was developed, showing how radionuclide therapy response improves as tumor oxygenation approaches normal tissue levels. The nuclides studied were {sup 90}Y, {sup 131}I, {sup 177}Lu, and {sup 211}At. The absorbed dose levels required for a tumor control probability (TCP) of 0.990 are compared for three different log-normal pO{sub 2}-distributions: {mu}{sub 1} = 2.483, {sigma}{sub 1} = 0.711; {mu}{sub 2} = 2.946, {sigma}{sub 2} = 0.689; {mu}{sub 3} = 3.689, and {sigma}{sub 3} = 0.330. The normal tissue absorbed doses will, in turn, depend on this. These distributions were chosen to represent the expected oxygen levels in an untreated hypoxic tumor, a hypoxic tumor treated with an anti-VEGF agent, and in normal, fully-oxygenated tissue, respectively. The former two are fitted to experimental data. The geometric oxygen distributions are simulated using two different patterns: one Monte Carlo based and one radially increasing, while keeping the log-normal volumetric distributions intact. Oxygen and activity are distributed, according to the same pattern. Results: As tumor pO{sub 2

Lysosomal Membrane Permeabilization is an Early Event in Sigma-2 Receptor Ligand Mediated Cell Death in Pancreatic Cancer

Directory of Open Access Journals (Sweden)

Hornick John R

2012-05-01

Full Text Available Abstract Background Sigma-2 receptor ligands have been studied for treatment of pancreatic cancer because they are preferentially internalized by proliferating cells and induce apoptosis. This mechanism of apoptosis is poorly understood, with varying reports of caspase-3 dependence. We evaluated multiple sigma-2 receptor ligands in this study, each shown to decrease tumor burden in preclinical models of human pancreatic cancer. Results Fluorescently labeled sigma-2 receptor ligands of two classes (derivatives of SW43 and PB282 localize to cell membrane components in Bxpc3 and Aspc1 pancreatic cancer cells and accumulate in lysosomes. We found that interactions in the lysosome are critical for cell death following sigma-2 ligand treatment because selective inhibition of a protective lysosomal membrane glycoprotein, LAMP1, with shRNA greatly reduced the viability of cells following treatment. Sigma-2 ligands induced lysosomal membrane permeabilization (LMP and protease translocation triggering downstream effectors of apoptosis. Subsequently, cellular oxidative stress was greatly increased following treatment with SW43, and the hydrophilic antioxidant N-acetylcysteine (NAC gave greater protection against this than a lipophilic antioxidant, α-tocopherol (α-toco. Conversely, PB282-mediated cytotoxicity relied less on cellular oxidation, even though α-toco did provide protection from this ligand. In addition, we found that caspase-3 induction was not as significantly inhibited by cathepsin inhibitors as by antioxidants. Both NAC and α-toco protected against caspase-3 induction following PB282 treatment, while only NAC offered protection following SW43 treatment. The caspase-3 inhibitor DEVD-FMK offered significant protection from PB282, but not SW43. Conclusions Sigma-2 ligand SW43 commits pancreatic cancer cells to death by a caspase-independent process involving LMP and oxidative stress which is protected from by NAC. PB282 however undergoes a

Scattering of massless lumps and non-local charges in the two-dimensional classical non-linear sigma-model

International Nuclear Information System (INIS)

Luescher, M.; Pohlmeyer, K.

1977-09-01

Finite energy solutions of the field equations of the non-linear sigma-model are shown to decay asymptotically into massless lumps. By means of a linear eigenvalue problem connected with the field equations we then find an infinite set of dynamical conserved charges. They, however, do not provide sufficient information to decode the complicated scattering of lumps. (orig.) [de

Thermodynamic modeling of neptunium(V) solubility in concentrated Na-CO3-HCO3-Cl-ClO4-H-OH-H2O systems

International Nuclear Information System (INIS)

Novak, C.F.; Roberts, K.E.

1994-01-01

Safety assessments of nuclear waste repositories often require estimation of actinide solubilities as a function of groundwater composition. Although considerable amount of research has been done on the solubility and speciation of actinides, relatively little has been done to unify these data into a model applicable to concentrate brines. Numerous authors report data on the aqueous chemical properties of Np(V) in NaClO 4 , Na 2 CO 3 , and NaCl media, but a consistent thermodynamic model for predicting these properties is not available. To meet this need, a model was developed to describe the solubility of Np(V) in Na-Cl-ClO 4 -CO 3 aqueous systems, based on the Pitzer activity coefficient formalism for concentrated electrolytes. Hydrolysis and/or carbonate complexation are the dominant aqueous reactions with neptunyl in these systems. Literature data for neptunyl extraction and solubility, and solubility data that the authors developed, are used to parameterize an integrated model for Np(V) solubility in the Np(V)-Na-CO 3 -HCO 3 -Cl-ClO 4 -H-OH-H 2 O system. The resulting model is tested against additional solubility data, and compared with Np(V) solubility experiments in complex synthetic brines

Measurement of the $\\Sigma \\pi$ photoproduction line shapes near the $\\Lambda(1405)$

Energy Technology Data Exchange (ETDEWEB)

Moriya, K; Adhikari, K P; Adikaram, D; Aghasyan, M; Anderson, M D; Anefalos Pereira, S; Ball, J; Baltzell, N A; Battaglieri, M; Batourine, V; Bedlinskiy, I; Bellis, M; Biselli, A S; Bono, J; Boiarinov, S; Briscoe, W J; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Cole, P L; Collins, P; Crede, V; D& #x27; Angelo, A; Dashyan, N; De Sanctis, E; De Vita, R; Deur, A; Dey, B; Djalali, C; Doughty, R; Dupre, R; Egiyan, H; El Fassi, L; Eugenio, P; Fedotov, G; Fegan, S; Fersch, R; Fleming, J A; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guidal, M; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Heddle, D; Hicks, K; Ho, D; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Keller, D; Khandaker, M; Khertarpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, A; Kubarovsky, V; Kuleshov, S V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I.J. D; Markov, N; Mayer, M; McCracken, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mineeva, T; Mokeev, V; Montgomery, R A; Munevar, E; Munoz Camacho, C; Nadel-Turonski, P; Nasseripour, R; Nepali, C S; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Phelps, E; Phillips, J J; Pisano, S; Pivnyuk, N; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Rimal, D; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatio, F; Saini, M S; Salgado, C; Schott, D; Seder, E; Seraydaryan, H; Sharabian, Y G; Smith, E S; Smith, G D; Sober, D I; Stepanyan, S S; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tang, W; Taylor, S; Taylor, C E; Tian, Ye; Tkachenko, S; Torayev, B; Ungaro, M; Vernarsky, B; Vlassov, A V; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P

2013-03-01

The reaction {gamma} + p -> K{sup +} + {Sigma} + {p}i was used to determine the invariant mass distributions or "line shapes" of the {Sigma}{sup +} {pi}{sup -}, {Sigma}{sup -} {pi}{sup +} and {Sigma}{sup 0} {pi}{sup 0} final states, from threshold at 1328 MeV/c^2 through the mass range of the {Lambda}(1405) and the {Lambda}(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W < 2.85 GeV. The three mass distributions differ strongly in the vicinity of the I=0 {Lambda}(1405), indicating the presence of substantial I=1 strength in the reaction. Background contributions to the data from the {Sigma}{sup 0}(1385) and from K* {Sigma} production were studied and shown to have negligible influence. To separate the isospin amplitudes, Breit-Wigner model fits were made that included channel-coupling distortions due to the Nkbar threshold. A best fit to all the data was obtained after including a phenomenological I=1, J{sup P} = 1/2{sup -} amplitude with a centroid at 1394\\pm20 MeV/c^2 and a second I=1 amplitude at 1413\\pm10 MeV/c^2. The centroid of the I=0 {Lambda}(1405) strength was found at the {Sigma} {pi} threshold, with the observed shape determined largely by channel-coupling, leading to an apparent overall peak near 1405 MeV/c^2.

On the zero mass limit of the non linear sigma model in four dimensions

International Nuclear Information System (INIS)

Gomes, M.; Koeberle, R.

The existence of the zero mass limit for the non-linear sigma-model in four dimensions is shown to all orders in renormalized perturbation theory. The main ingredient in the proof is the imposition of many current axial vector Ward identities and the tool used is Lowenstein's momentum-space subtraction procedure. Instead of introducing anisotropic symmetry breaking mass terms, which do not vanish in the symmetry limit, it is necessary to allow for 'soft' anisotropic derivative coupling in order to obtain the correct Ward indentities [pt

THE IMPROVEMENT OF PROCESSES’ QUALITY IN ORGANISATIONS USING THE SIX SIGMA CONCEPT

Directory of Open Access Journals (Sweden)

MĂDĂLINA BRUTU

2010-01-01

Full Text Available Six Sigma is a problem-solving methodology. In fact, it’s the most effective problem-solving methodology available for improving business and organizational performance. Bill Smith from Motorola first developed in 1986 the specific elements of Six Sigma. At the beginning, it was a set of practices which have been used in the manufacturing processes in order to eliminate the defects but, as time passed, the concept has been extended so as to be used in other types of businesses, too. The 6th Sigma level corresponds to a 99,9997% performance, respectively 3,4 defects per a million of occasions. A Six Sigma process is a redesigned business process and has three basic elements: Process Improvement; Designing/redesigning the process; The Process Management.

Naval Surface Warfare Center Dahlgren Division: application of Lean Six Sigma in the pre-award procurement process

OpenAIRE

Himes, Kristy M.; Salisbury, Constance M.

2008-01-01

Joint Applied Project This Project outlines Lean Six Sigma principles, provides examples of Lean Six Sigma events, and analyzes principles that can be applied to Navy acquisition and contracting. The objective of this project is to: (1) provide an overview of Lean Six Sigma principles in contracting and acquisition; (2) identify Navy contracting processes that have and can be analyzed using Lean Six Sigma principles; (3) explore how Lean Six Sigma can be applied to interpret and implem...

Design Principles of A Sigma-delta Flux-gate Magnetometer

Science.gov (United States)

Magnes, W.; Valavanoglou, A.; Pierce, D.; Frank, A.; Schwingenschuh, K.

A state-of-the-art flux-gate magnetometer is characterised by magnetic field resolution of several pT in a wide frequency range, low power consumption, low weight and high robustness. Therefore, flux-gate magnetometers are frequently used for ground-based Earth's field observation as well as for measurements aboard scientific space missions. But both traditional analogue and recently developed digital flux-gate magnetometers need low power and high-resolution analogue-to-digital converters for signal quan- tization. The disadvantage of such converters is the low radiation hardness. This fact has led to the idea of combining a traditional analogue flux-gate regulation circuit with that of a discretely realized sigma-delta converter in order to get a radiation hard and further miniaturized magnetometer. The name sigma-delta converter is derived from putting an integrator in front of a 1-bit delta modulator which forms the sigma-delta loop. It is followed by a digital decimation filter realized in a field-programmable gate array (FPGA). The flux-gate regulation and the sigma-delta loop are quite similar in the way of realizing the integrator and feedback circuit, which makes it easy to com- bine these two systems. The presented talk deals with the design principles and the results of a first bread board model.

Oxygen nonstoichiometry and ionic transport properties of La0.4Sr0.6CoO3-delta .

Science.gov (United States)

Sitte, W; Bucher, E; Benisek, A; Preis, W

2001-09-01

Homogeneous samples of La0.4Sr0.6CoO3-delta were obtained by the glycine nitrate process. The oxygen nonstoichiometry was determined from oxygen exchange measurements as a function of oxygen partial pressure (10(-4) bar PO2 PO2-range between 10(-4) and 10(-2) bar to yield D and the ionic conductivity sigma(i) from the long time solution of the diffusion equation. Values for D from polarization measurements at T= 775 degrees C and from oxygen exchange measurements at T= 725 degrees C are in good agreement with each other. D and sigma(1) increase with increasing PO2 (10(-4) to 10(-2) bar). The ionic conductivity shows a maximum at 3-delta approximately 2.82 and decreases with decreasing oxygen content indicating the possible formation of vacancy ordered structures.

The C-Terminal RpoN Domain of sigma54 Forms an unpredictedHelix-Turn-Helix Motif Similar to domains of sigma70

Energy Technology Data Exchange (ETDEWEB)

Doucleff, Michaeleen; Malak, Lawrence T.; Pelton, Jeffrey G.; Wemmer, David E.

2005-11-01

The ''{delta}'' subunit of prokaryotic RNA-polymerase allows gene-specific transcription initiation. Two {sigma} families have been identified, {sigma}{sup 70} and {sigma}{sup 54}, which use distinct mechanisms to initiate transcription and share no detectable sequence homology. Although the {sigma}{sup 70}-type factors have been well characterized structurally by x-ray crystallography, no high-resolution structural information is available for the {sigma}{sup 54}-type factors. Here we present the NMR derived structure of the C-terminal domain of {sigma}{sup 54} from Aquifex aeolicus. This domain (Thr323 to Gly389), which contains the highly conserved RpoN box sequence, consists of a poorly structured N-terminal tail followed by a three-helix bundle, which is surprisingly similar to domains of the {sigma}{sup 70}-type proteins. Residues of the RpoN box, which have previously been shown to be critical for DNA binding, form the second helix of an unpredicted helix-turn-helix motif. This structure's homology with other DNA binding proteins, combined with previous biochemical data, suggest how the C-terminal domain of {sigma}{sup 54} binds to DNA.

Application of Six Sigma towards improving surgical outcomes.

Science.gov (United States)

Shukla, P J; Barreto, S G; Nadkarni, M S

2008-01-01

Six Sigma is a 'process excellence' tool targeting continuous improvement achieved by providing a methodology for improving key steps of a process. It is ripe for application into health care since almost all health care processes require a near-zero tolerance for mistakes. The aim of this study is to apply the Six Sigma methodology into a clinical surgical process and to assess the improvement (if any) in the outcomes and patient care. The guiding principles of Six Sigma, namely DMAIC (Define, Measure, Analyze, Improve, Control), were used to analyze the impact of double stapling technique (DST) towards improving sphincter preservation rates for rectal cancer. The analysis using the Six Sigma methodology revealed a Sigma score of 2.10 in relation to successful sphincter preservation. This score demonstrates an improvement over the previous technique (73% over previous 54%). This study represents one of the first clinical applications of Six Sigma in the surgical field. By understanding, accepting, and applying the principles of Six Sigma, we have an opportunity to transfer a very successful management philosophy to facilitate the identification of key steps that can improve outcomes and ultimately patient safety and the quality of surgical care provided.

Generic Lean Six Sigma project definitions in publishing

NARCIS (Netherlands)

de Koning, H.; Does, R.J.M.M.; Groen, A.; Kemper, B.P.H.

2010-01-01

Purpose - Many companies in the publishing industry are facing the task of developing new business models and becoming more efficient and effective in execution. Lean Six Sigma (LSS) is a unified framework for systematically developing efficiency and quality improvements; it can help realize

Sistem Informasi Kinerja Layanan Laboratorium Medis dengan Metode Six Sigma

Directory of Open Access Journals (Sweden)

Anindita Kusumastuti Dewi

2016-01-01

Full Text Available Medical Laboratory currently holds a very important role in medicine. Evaluation of laboratory quality plays a very important to maintain accurate laboratory results. This study aims to design an information system performance based on the same perception of medical laboratory services from customers using Six Sigma methods and frameworks using ServQual questionnaire. Selection of Six Sigma itself is based on this method can measure the extent to which each process deviates from its purpose as well as to reduce the variation of each of the attributes.  Six Sigma DMAIC namely (Define, Measure, Analyze, Improve, Control preferred because the end result will not yield new products, but only improvements on existing processes. The results of this calculation will be presented in the form of a dashboard for easier management in understanding the results of the evaluation. From the system can be obtained an average value of consumer perceptions terhdap performance today is 2,883, consumer expectations on the performance of 3.3768, the gap between the perceptions and expectations of consumers is -0.4936, customer satisfaction will be the performance of the current 85.37%, the value of 423 360 DPMO and sigma value there at the 2.07664 level.   Keywords: Laboratory Performance; Six Sigma; Servqual; Dashboard

Structure of NaH/sub 2/As/sub 3/O/sub 9/: A new condensed arseniate anion

Energy Technology Data Exchange (ETDEWEB)

Driss, A.; Jouini, T.; Durif, A.; Averbuch-Pouchot, M.T.

1988-09-15

(NaH/sub 2/As/sub 3/O/sub 9/)/sub n/, M/sub r/=393.77, triclinic, Panti 1, a=7.167(1), b=7.575(1), c=7.850(1) A, ..cap alpha..=109.89(1), ..beta..=107.27(1), ..gamma..=106.15(1)/sup 0/, V=346.9 A/sup 3/, Z=2, D/sub m/=3.58, D/sub x/=3.77 g cm/sup -3/, F(000)=368, lambda(Mo K anti ..cap alpha..)=0.7107 A, ..mu..=142 cm/sup -1/, final R=0.034 and wR=0.039 for 1485 reflections with F > sigma(F). A new condensed arseniate anion is found. It consists of infinite (H/sub 2/As/sub 3/O/sub 9/)/sub n//sup n-/ chains built from As/sub 4/O/sub 14/ rings linked by bidentate bridging AsO/sub 4/ tetrahedra.

De praktijk van Lean Six Sigma

NARCIS (Netherlands)

Does, R.J.M.M.; de Koning, H.

2008-01-01

Zowel Lean als Six Sigma zijn benaderingen van kwaliteits- en efficiëntieverbetering die op dit moment sterk in de belangstelling staan van zowel de industrie als de dienstverlening. Lean Six Sigma integreert beide benaderingen. Ze wordt door sommigen gezien als panacee voor alle mogelijke

Lean Six Sigma in a hospital

NARCIS (Netherlands)

van den Heuvel, J.; Does, R.J.M.M.; de Koning, H.

2006-01-01

Abstract Hospitals today face major challenges. Patients demand quality of care to be improved continuously. Health insurance companies demand the lowest possible prices. Lean Six Sigma is a program that can help healthcare providers to achieve these (seemingly) conflicting goals. Lean Six Sigma is

SIGMA Experimental Facility; Facilidad Experimental SIGMA

Energy Technology Data Exchange (ETDEWEB)

Rivarola, Martin; Florido, Pablo; Gonzalez, Jose; Brasnarof, Daniel; Orellano, Pablo; Bergallo, Juan [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Grupo de Disenos Avanzados y Evaluacion Economica, Complejo Tecnologico Pilcaniyeu (Argentina)

2000-07-01

The SIGMA ( Separacion Isotopica Gaseosa por Metodos Avanzados) concept is outlined.The old gaseous diffusion process to enrich uranium has been updated to be economically competitive for small production volumes.Major innovations have been introduced in the membrane design and in the integrated design of compressors and diffusers.The use of injectors and gas turbines has been also adopted.The paper describes the demonstration facility installed by the Argentine Atomic Energy Commission.

CLC in packed beds using syngas and CuO/Al2O3: Model description and experimental validation

International Nuclear Information System (INIS)

Hamers, H.P.; Gallucci, F.; Cobden, P.D.; Kimball, E.; Sint Annaland, M. van

2014-01-01

Highlights: • CLC with CuO/Al 2 O 3 and syngas and air has been demonstrated experimentally. • Model predicts accurately only if kinetics describe the complete solid reduction. • CuO/Al 2 O 3 is proven to catalyze the reversed water gas shift reaction. • H 2 O is more effective to suppress carbon deposition on CuO/Al 2 O 3 than CO 2 . • The OC reaction rate is not permanently affected by exposure to H 2 S. - Abstract: The objective of this work is to study the performance of the oxygen carrier in a packed bed with periodic switching between oxidizing and reducing conditions. In this paper the performance of CuO/Al 2 O 3 as the oxygen carrier in a packed bed reactor with syngas as the fuel are investigated, while also studying the (possible) carbon deposition and the effect of sulphur impurities on the stability of the carrier. Both experiments and simulations are used in this work. Cyclic experiments (oxidation with air and reduction with syngas) have been carried out in a lab scale packed bed reactor with 13 wt% CuO/Al 2 O 3 . The experimental results were well described by a 1D reactor model, provided that critical attention was given to the reaction rate for the complete reduction reaction, including a dramatic decrease in reaction rate at high solid conversions. Feeding syngas (p H2 = p CO = 0.1 bar) resulted in 1.1% carbon deposition of the feed. Steam was proven to be more effective in reducing carbon deposition than CO 2 . Moreover, it has been found that CuO/Al 2 O 3 catalyzed the water gas shift reaction and the reaction rate was not permanently affected by exposure to H 2 S, two key factors for CLC operation. The results of this work imply that CuO/Al 2 O 3 is an effective oxygen carrier as the first packed bed reactor in a TSCLC process and that the developed model is able to describe the performance at larger scales accurately

The geometric background-field method, renormalization and the Wess-Zumino term in non-linear sigma-models

International Nuclear Information System (INIS)

Mukhi, S.

1986-01-01

A simple recursive algorithm is presented which generates the reparametrization-invariant background-field expansion for non-linear sigma-models on manifolds with an arbitrary riemannian metric. The method is also applicable to Wess-Zumino terms and to counterterms. As an example, the general-metric model is expanded to sixth order and compared with previous results. For locally symmetric spaces, we actually obtain a general formula for the nth order term. The method is shown to facilitate the study of models with Wess-Zumino terms. It is demonstrated that, for chiral models, the Wess-Zumino term is unrenormalized to all orders in perturbation theory even when the model is not conformally invariant. (orig.)

LEAN Y SEIS SIGMA EN LAS UNIVERSIDADES PÚBLICAS DE CASTILLA Y LEÓN

OpenAIRE

González de Diego, Clara Mª

2017-01-01

La metodología Lean Manufacturing y la filosofía Seis Sigma han cobrado un papel de vital importancia en el mundo de la industria y de la producción. Es por ello que, a partir de la propuesta lanzada por la Asociación Española para la Calidad (AEC), se ha decidido observar el grado de explicación de una serie de conceptos de calidad (conceptos básicos, diseño de experimentos, normas de calidad y Seis Sigma) y de producción (MRP, JIT y Lean Manufacturing) en las titulacione...

A new molybdenum trioxide hydrate MoO3.1/3H2O and a new monoclinic form of MoO3

International Nuclear Information System (INIS)

Harb, F.; Gerand, B.; Nowogrocki, G.; Figlarz, M.

1986-01-01

A new hydrate of molybdenum trioxide MoO 3 .1/3H 2 O has been obtained by hydrothermal treatment at 110 0 C of either aqueous suspensions of MoO 3 .2H 2 O or aqueous molybdic acid solutions. The hydrate crystallizes in the orthorhombic system, lattice parameters are given; a structural model is proposed by comparison with the isostructural WO 3 .1/3H 2 O phase. The dehydration of MoO 3 .1/3H 2 O leads to a new anhydrous molybdenum trioxide, monoclinic, the structure of which is of ReO 3 type [fr

THE SUBSTELLAR POPULATION OF {sigma} ORIONIS: A DEEP WIDE SURVEY

Energy Technology Data Exchange (ETDEWEB)

Bejar, V. J. S.; Rebolo, R. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Zapatero Osorio, M. R.; Martin, E. L. [Centro de Astrobiologia (INTA-CSIC), Crta. Ajalvir km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Caballero, J. A.; Barrado, D. [Centro de Astrobiologia (INTA-CSIC), ESAC campus, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Mundt, R.; Bailer-Jones, C. A. L., E-mail: vbejar@iac.es, E-mail: mosorio@cab.inta-csic.es, E-mail: ege@cab.inta-csic.es, E-mail: rrl@iac.es, E-mail: caballero@cab.inta-csic.es, E-mail: barrado@cab.inta-csic.es, E-mail: mundt@mpia.de, E-mail: calj@mpia.de [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)

2011-12-10

wavelengths longer than 5.8 {mu}m. These are probably related to the presence of disks, most of which are 'transition disks'. We have also calculated the initial mass spectrum (dN/dm) of {sigma} Orionis from very low mass stars ({approx}0.10 M{sub Sun }) to the deuterium-burning mass limit (0.012-0.013 M{sub Sun }), i.e., complete in the entire brown dwarf regime. This mass spectrum is a rising function toward lower masses and can be represented by a power-law distribution (dN/dm {proportional_to} m{sup -{alpha}}) with an exponent {alpha} of 0.7 {+-} 0.3 for an age of 3 Myr.

Formation, stability and crystal structure of the {sigma} phase in Mo-Re-Si alloys

Energy Technology Data Exchange (ETDEWEB)

Bei, H., E-mail: beih@ornl.gov [Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831 (United States); Yang, Y., E-mail: ying.yang@computherm.com [CompuTherm LLC, Madison, WI 53719 (United States); Viswanathan, G.B. [Air Force Research Laboratory, Wright-Patterson AFB, OH 45433 (United States); Rawn, C.J.; George, E.P. [Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831 (United States)] [University of Tennessee, Department of Materials Science and Engineering, Knoxville, TN 37996 (United States); Tiley, J. [Air Force Research Laboratory, Wright-Patterson AFB, OH 45433 (United States); Chang, Y.A. [CompuTherm LLC, Madison, WI 53719 (United States)] [University of Wisconsin-Madison, Madison, WI 53705 (United States)

2010-10-15

The formation, stability and crystal structure of the {sigma} phase in Mo-Re-Si alloys were investigated. Guided by thermodynamic calculations, six critically selected alloys were arc melted and annealed at 1600 deg. C for 150 h. Their as-cast and annealed microstructures, including phase fractions and distributions, the compositions of the constituent phases and the crystal structure of the {sigma} phase were analyzed by thermodynamic modeling coupled with experimental characterization by scanning electron microscopy, electron probe microanalysis, X-ray diffraction and transmission electron microscopy. Two key findings resulted from this work. One is the large homogeneity range of the {sigma} phase region, extending from binary Mo-Re to ternary Mo-Re-Si. The other is the formation of a {sigma} phase in Mo-rich alloys either through the peritectic reaction of liquid + Mo{sub ss} {yields} {sigma} or primary solidification. These findings are important in understanding the effects of Re on the microstructure and providing guidance on the design of Mo-Re-Si alloys.

Six Sigma: blauwdruk voor de kenniseconomie.

NARCIS (Netherlands)

Does, R.J.M.M.; de Mast, J.

2005-01-01

Abstract Six Sigma is zo langzamerhand een niet weg te denken programma voor kwaliteits- en efficiencyverbeteringen. Het heeft met name voor enorme successen gezorgd in productiebedrijven. Six Sigma ligt ook onder vuur: het zou een trend zijn die voorbij gaat. De auteurs van dit artikel zijn het van

Sigma meson in heavy ion collision

International Nuclear Information System (INIS)

Cristian, Ivan; Fuchs, Christian

2004-01-01

We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)

Magnetic properties of Hubbard-sigma model with three-dimensionality

International Nuclear Information System (INIS)

Yamamoto, Hisashi; Tatara, Gen; Ichinose, Ikuo; Matsui, Tetsuo.

1990-05-01

It has been broadly accepted that the magnetism may play an important role in the high-T c superconductivity in the lamellar CuO 2 materials. In this paper, based on a Hubbard-inspired CP 1 or S 2 nonlinear σ model, we give a quantitative study of some magnetic properties in and around the Neel ordered state of three-dimensional quantum antiferromagnets such as La 2 CuO 4 with and without small hole doping. Our model is a (3+1) dimensional effective field theory describing the low energy spin dynamics of a three-dimensional Hubbard model with a very weak interlayer coupling. The effect of hole dynamics is taken into account in the leading approximation by substituting the CP 1 coupling and the spin-wave velocity with 'effective' ones determined by the concentration and the one-loop correction of hole fermions. Stationary-phase equations for the one-loop effective potential of S 2 model are analyzed. Based on them, various magnetic properties of the system, such as the behavior of Neel temperature, spin correlation length, staggered magnetization, specific heat and susceptibility as functions of anisotropic parameter, temperature, etc. are investigated in detail. The results show that our anisotropic field theory model with certain values of parameters gives a good description of the magnetic properties in both the ordered and the disordered phases indicated by experiments on La 2 CuO 4 . The part of the above results is supported by the renormalization-group analysis. In the doped case it is observed that the existence of holes destroys the long-range order and their hopping effect is large. (author)

Analisis Pengendalian Kualitas Super Absorbent Polymer Dengan Menggunakan Metode Six Sigma

Directory of Open Access Journals (Sweden)

Rosihin Rosihin

2017-07-01

Full Text Available Quality control is an effort to increase customer satisfaction and minimize damage. Super Absorbent Polymer which is a product as a raw material for making baby diapers / elderly and sanitary napkins. In Super Absorbent Polymer, defects usually found in the colour contamination that there is a dark colour on the product, print labels mistakes and packaging defects. This study aims to determine the value of DPMO and sigma level, identify the efforts which is taken to reduce disability, identify the types of disability, and find the main factors causing disability. Six Sigma method is used to analyze data with define, measure, analyze, improve and control. The quantitative data obtained by direct observation of quality problems. By using the method of six sigma can be seen that the quality of the resulting product is quite good that is 3.07 sigma with a damage rate of 58,624 for a million production (DPMO. The three highest defect product causes are color contamination of 93.34%, misprint of 3.55%, and packaging damage as much as 3.11%. The main factor causing defects is the engine factor for the type of colour contamination defect,. The type of improper defects in the packaging labels and main factor for the packaging defects is the human factor.kecacatan rusaknya kemasan faktor utama ialah faktor manusia.

The Adler-Weisberger sum rule and the sigma-Commutator for the Kaon-Neutron system

International Nuclear Information System (INIS)

Rodriguez-Vargas, A.M.; Violini, G.

1980-01-01

The axial coupling constant is determined from Kp and Kn Adler-Weisberger sum rule, in correspondence with different anti K N unphysical region parameterizations. Moreover a new calculation of the sigma-term is presented. It is shown that by using Kn data it is possible to reduce considerably the error on sigma sup(KK)sub(NN) with respect to the analogous calculation for Kp, but that an accurate determination requires a good value for the psub(3/2) anti K N scattering length. By preferring the solutions which lead to a positive sigma-term, one obtains sigma sup(KK)sub(NN) = 638 +- 438 MeV. (orig.) 891 HSI/orig. 892 HIS

Little strings, quasi-topological sigma model on loop group, and toroidal Lie algebras

Directory of Open Access Journals (Sweden)

Meer Ashwinkumar

2018-03-01

Full Text Available We study the ground states and left-excited states of the Ak−1 N=(2,0 little string theory. Via a theorem by Atiyah [1], these sectors can be captured by a supersymmetric nonlinear sigma model on CP1 with target space the based loop group of SU(k. The ground states, described by L2-cohomology classes, form modules over an affine Lie algebra, while the left-excited states, described by chiral differential operators, form modules over a toroidal Lie algebra. We also apply our results to analyze the 1/2 and 1/4 BPS sectors of the M5-brane worldvolume theory.

Little strings, quasi-topological sigma model on loop group, and toroidal Lie algebras

Science.gov (United States)

Ashwinkumar, Meer; Cao, Jingnan; Luo, Yuan; Tan, Meng-Chwan; Zhao, Qin

2018-03-01

We study the ground states and left-excited states of the Ak-1 N = (2 , 0) little string theory. Via a theorem by Atiyah [1], these sectors can be captured by a supersymmetric nonlinear sigma model on CP1 with target space the based loop group of SU (k). The ground states, described by L2-cohomology classes, form modules over an affine Lie algebra, while the left-excited states, described by chiral differential operators, form modules over a toroidal Lie algebra. We also apply our results to analyze the 1/2 and 1/4 BPS sectors of the M5-brane worldvolume theory.

The six sigma program: an empirical study of brazilian companies.

OpenAIRE

Carvalho, Marly Monteiro de; Ho, Linda Lee; Pinto, Silvia Helena Boarin

2014-01-01

Purpose – The purpose of this paper is to assess the status of Six Sigma's status in Brazilian companies and understand the integration of this program with other quality management approaches. Additionally, the critical success factors (CSFs) for Six Sigma implementation and primary Six Sigma program characteristics were identified. Finally, the results of the used of Six Sigma were analysed. Design/methodology/approach – An extensive literature review illustrates the primary Six Sigma c...

Study of $\\Sigma$(1385) and $\\Xi$(1321) hyperon and antihyperon production in deep inelastic muon scattering

CERN Document Server

Adolph, C; Alexakhin, V.Yu; Alexandrov, Yu.; Alexeev, G D; Amoroso, A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Berlin, A; Bernhard, J; Bertini, R; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Buchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O.Yu; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M., Jr; Fischer, H; Franco, C; von Hohenesche, N. du Fresne; Friedrich, J M; Frolov, V; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Hoppner, Ch; Horikawa, N; d'Hose, N; Huber, S; Ishimoto, S; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu. A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kuchinski, N; Kunne, F.; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu. V; Miyachi, Y; Morreale, A; Nagaytsev, A; Nagel, T.; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Novy, J; Nowak, W D; Nunes, A.S.; Olshevsky, A G; Ostrick, M; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Reicherz, G; Rocco, E; Rodionov, V; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T.; Schmidt, A; Schmidt, K; Schmitt, L; Schmiden, H; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L.; Sinha, L; Sirtl, S; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Thibaud, F; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M

2013-01-01

Large samples of $\\Lambda$, $\\Sigma(1385)$ and $\\Xi(1321)$ hyperons produced in deep-inelastic muon scattering off a $^6$LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of $\\Sigma(1385)^+$, $\\Sigma(1385)^-$, $\\bar{\\Sigma}(1385)^-$, $\\bar{\\Sigma}(1385)^+$, $\\Xi(1321)^-$, and $\\bar{\\Xi}(1321)^+$ hyperons decaying into $\\Lambda(\\bar{\\Lambda})\\pi$ were measured. The heavy hyperon to $\\Lambda$ and heavy antihyperon to $\\bar{\\Lambda}$ yield ratios were found to be in the range 3.8% to 5.6% with a relative uncertainty of about 10%. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator.

IDENTIFICATION AND SELECTION OF SIX SIGMA PROJECTS

Directory of Open Access Journals (Sweden)

Abdalhkeim FA. Flifel

2017-04-01

Full Text Available Six Sigma is a well-structured and proven methodology for improving organizational performance. It helps achieving the goals of the organization through the use of project-driven approach. The implementation of Six sigma approach depends on proper identification and selection of projects, moreover, the selection of right Six sigma projects is one of the critical success factors of six sigma efforts. The paper provides the sources for the identification of potential projects, top down and bottom up approaches, the process of selection of projects, guidelines that assist the selection of appropriate projects, selection criteria which must be precisely chosen in accordance with the objectives, needs and capabilities of the organization as well as sophisticated techniques and tools recommended in the literature for the selection of projects.

TINJAUAN KUALITAS PADA AEROSOL CAN Ø 65 X 124 DENGAN PENDEKATAN METODE SIX SIGMA PADA LINE ABM 3 DEPARTEMEN ASSEMBLY

Directory of Open Access Journals (Sweden)

Mohammad Kholil

2017-02-01

Full Text Available Perkembangan dunia industri akan selalu terdapat persaingan. Kepuasan konsumen menjadi faktor utama yang mampu menentukan kemenangan dalam persaingan di dunia industri. Kepuasan konsumen dapat diraih salah satunya dengan menjaga kualitas produk yang dihasilkan. Hal inilah yang mendasari untuk terus melakukan perbaikan kualitas. Penelitian ini difokuskan pada penurunan tingkat reject  yang terdapat pada proses produksi Aerosol Can Ø65 X 124 dengan metode Six Sigma. Metode Six Sigma ini disusun berdasarkan sebuah metodologi penyelesaian masalah yang sederhana-DMAIC, yaitu: Define (merumuskan, Measure (mengukur, Analyze (menganalisa, Improve (memperbaiki dan Control (mengendalikan, yang menggabungkan bermacam – macam  perangkat statistik serta pendekatan perbaikan proses yang lainnya.Berdasarkan hasil penelitian diperoleh DPMO sebesar 22.749,787 dengan nilai sigma 3,50. Dengan Weld Problem sebagai jumlah reject terbesar yaitu sebanyak  311.226 pcs atau 37,91% dari total reject keseluruhan. Dari analisa Fishbone Diagram dan FMEA didapat  penyebab dari Weld Problem, yaitu: Ukuran material tidak standar, jenis Material yang berbeda-beda, kemampuan Operator kurang, SOP tidak dijalankan, profil Roll Weld aus dan kondisi mesin tidak normal, untuk itu perlu dilakukan perbaikan guna mengurangi jumlah kerusakan produk.

Involvement of direct inhibition of NMDA receptors in the effects of sigma-receptor ligands on glutamate neurotoxicity in vitro.

Science.gov (United States)

Nishikawa, H; Hashino, A; Kume, T; Katsuki, H; Kaneko, S; Akaike, A

2000-09-15

This study was performed to examine the roles of the N-methyl-D-aspartate (NMDA) receptor/phencyclidine (PCP) channel complex in the protective effects of sigma-receptor ligands against glutamate neurotoxicity in cultured cortical neurons derived from fetal rats. A 1-h exposure of cultures to glutamate caused a marked loss of viability, as determined by Trypan blue exclusion. This acute neurotoxicity of glutamate was prevented by NMDA receptor antagonists. Expression of sigma(1) receptor mRNA in cortical cultures was confirmed by reverse transcription polymerase chain reaction (RT-PCR). sigma Receptor ligands with affinity for NMDA receptor channels including the PCP site, such as (+)-N-allylnormetazocine ((+)-SKF10,047), haloperidol, and R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane ((-)-PPAP), prevented glutamate neurotoxicity in a concentration-dependent manner. In contrast, other sigma-receptor ligands without affinity for NMDA receptors, such as carbetapentane and R(+)-3-(3-hydroxyphenyl)-N-propylpiperidine ((+)-3-PPP), did not show neuroprotective effects. Putative endogenous sigma receptor ligands such as pregnenolone, progesterone, and dehydroepiandrosterone did not affect glutamate neurotoxicity. The protective effects of (+)-SKF10,047, haloperidol, and (-)-PPAP were not affected by the sigma(1) receptor antagonist rimcazole. These results suggested that a direct interaction with NMDA receptors but not with sigma receptors plays a crucial role in the neuroprotective effects of sigma receptor ligands with affinity for NMDA receptors.

The exact mass-gap of the supersymmetric CP$^{N-1}$ sigma model

CERN Document Server

Evans, J M; Evans, Jonathan M; Hollowood, Timothy J

1995-01-01

A formula for the mass-gap of the supersymmetric \\CP^{n-1} sigma model (n > 1) in two dimensions is derived: m/\\Lambda_{\\overline{\\rm MS}}=\\sin(\\pi\\Delta)/(\\pi\\Delta) where \\Delta=1/n and m is the mass of the fundamental particle multiplet. This result is obtained by comparing two expressions for the free-energy density in the presence of a coupling to a conserved charge; one expression is computed from the exact S-matrix of K\\"oberle and Kurak via the thermodynamic Bethe ansatz and the other is computed using conventional perturbation theory. These calculations provide a stringent test of the S-matrix, showing that it correctly reproduces the universal part of the beta-function and resolving the problem of CDD ambiguities.

Integration of six sigma with lean production: an analysis through multiple cases

Directory of Open Access Journals (Sweden)

Thiago Henrique Pinheiro

2013-08-01

Full Text Available The intense competition between markets has taken companies, regardless of their size, to implement one or more quality improvement programs. One of the main purposes of these programs is the enhancement of company effectiveness and efficiency. There is today a growing interested in a proposal named Lean Six Sigma. Their objective is to apply six sigma concepts integrated with Lean Production. A model named Lean Six Sigma has raised interest, once its objective is to apply the concepts of the Six Sigma program integrating them with the principles of Lean Production. Six Sigma contributes with methods for problem identification, measurement and analysis, and the Lean Production offers techniques and procedures applied to reduce waste in the production. In this context, this paper aims at demonstrating the results of a field research, from which purpose was to identify relevant factors for Six Sigma implementation combined with Lean Production. To meet these objectives, three organizations from different industrial sectors were investigated. It was verified that in two of those companies, the programs were successfully implemented. Based on data analysis, it is possible to identify that one of the major difficulties encountered by the program leaders is related to the company’s human resources infra-structure. It is necessary to take into account that the conclusions are limited to a small sample of three units of analysis. However, this work offers the possibility of an analytical generalization.

Redesigning a joint replacement program using Lean Six Sigma in a Veterans Affairs hospital.

Science.gov (United States)

Gayed, Benjamin; Black, Stephen; Daggy, Joanne; Munshi, Imtiaz A

2013-11-01

In April 2009, an analysis of joint replacement surgical procedures at the Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, revealed that total hip and knee replacements incurred $1.4 million in non-Veterans Affairs (VA) care costs with an average length of stay of 6.1 days during fiscal year 2008. The Joint Replacement Program system redesign project was initiated following the Vision-Analysis-Team-Aim-Map-Measure-Change-Sustain (VA-TAMMCS) model to increase efficiency, decrease length of stay, and reduce non-VA care costs. To determine the effectiveness of Lean Six Sigma process improvement methods applied in a VA hospital. Perioperative processes for patients undergoing total joint replacement were redesigned following the VA-TAMMCS model--the VA's official, branded method of Lean Six Sigma process improvement. A multidisciplinary team including the orthopedic surgeons, frontline staff, and executive management identified waste in the current processes and initiated changes to reduce waste and increase efficiency. Data collection included a 1-year baseline period and a 20-month sustainment period. The primary endpoint was length of stay; a secondary analysis considered non-VA care cost reductions. Length of stay decreased 36% overall, decreasing from 5.3 days during the preproject period to 3.4 days during the 20-month sustainment period (P Lean and Six Sigma process improvement initiatives in a surgical practice, producing a 36% sustained reduction in length of stay and completely eliminating non-VA care for total hip and knee replacements while increasing total joint replacement volume at this medical center.

Effects of a novel, selective, sigma1-ligand, MS-377, on phencyclidine-induced behaviour.

Science.gov (United States)

Takahashi, S; Takagi, K; Horikomi, K

2001-07-01

Phencyclidine (PCP)-induced head-weaving is inhibited by a novel selective sigma1-ligand, (R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), but not by dopamine D2 antagonists. In the present study, we examined the effects of two potent and selective sigma1-ligands, MS-377 and N,N-dipropyl-2-(4-methoxy-3-(2-phenylethoxy)phenyl) ethylamine (NE-100), on PCP-induced rearing behaviour, hyperlocomotion and ataxia in comparison with the currently available antipsychotic agents with affinity for D2 receptors, haloperidol, sultopride and risperidone. Male Wistar rats or ddY mice were administered MS-377, NE-100, haloperidol, sultopride or risperidone, and PCP was administered 60 min later (in the case of NE-100 10 min later). Rearing behaviour, hyperlocomotion and ataxia were examined 10 min after PCP administration. MS-377, haloperidol, sultopride and risperidone dose-dependently inhibited PCP-induced rearing and hyperlocomotion, but did not antagonize PCP-induced ataxia. In contrast, the other selective sigma1-ligand, NE-100, did not affect any of the PCP-induced behaviour patterns in this study. These results suggest that there are at least two types of ligands for sigma1-receptors and that some sigma1-ligands, including MS-377, have more comprehensive effects against PCP-induced abnormal behaviour than other sigma1-ligands or D2 antagonists.

Six sigma critical success factors in manufacturing industries

Science.gov (United States)

Mustafa, Zainol; Jamaluddin, Z.

2017-04-01

The success of Six Sigma implementation is known to depend on a number of contributing factors. The purpose of this paper is to explore Six Sigma critical success factors (CSFs) in the context of Malaysian manufacturing organizations. Although Six Sigma success factors have been abundantly researched in the global context, in this paper, a maiden attempt is made to identify, through an extensive literature review, the CSFs for Six Sigma implementation followed by their validation using primary data collection from Malaysian manufacturing companies. A total of 33 indicators have thus been compiled through an extensive literature review which then been grouped into 6 contributing factors. These contributing success factors are then validated through an empirical research of selected Malaysian manufacturing companies at various stages of implementation of the Six Sigma process improvement methodology. There has been an overemphasis on the role and commitment of the management in the success of a Six Sigma program. Though it is undoubted, certain other factors also play an equally important role in ensuring that the Six Sigma programs are successful. The factor analysis of CSFs of the Malaysian manufacturing organizations selected in this study demonstrates that the top factor is a composite factor showing combination of the ability of the project teams to use the process management on quality initiative and a training using a proper analysis in problem solving. The CSFs extracted through the factor analysis could provide a basis for manufacturing organizations embarking on the Six Sigma journey to look beyond just management involvement. Thus, one can develop an integrated framework of other factors as outlined and give them appropriate priority and focus.

Effect of six sigma program on the number of surgeries cancellation.

Science.gov (United States)

Gheysari, Esmat; Yousefi, Hojatollah; Soleymani, Hossain; Mojdeh, Soheila

2016-01-01

Today, the rate of surgeries is increasing, but surgeries are canceled due to various reasons. Unexpected cancellation of surgeries not only results in disorder in the operating room schedule, but also causes stress for patients and their family and increases costs. We determined the number and causes of surgery cancellations and areas for improvement. This outcome evaluation of Six Sigma program was conducted on 850 cases after the implementation of the program and compared to that of 850 cases which received routine care before the program. Cases were selected through easy sampling during the study. Before the implementation, the number of cancellations was recorded daily and their reasons were investigated. Then, Six Sigma program was implemented in accordance with the reasons for each category and necessary steps were taken to prevent the cancellation of surgeries. Data were collected for 3 months using a three-section data collection form. For data analysis, distribution and relative frequency and chi-square test were used. The three categories of patient, physician, and hospital system were identified as the main causes. The highest rate of cancellation was related to ENT surgeries (74.19%). No cancellations were made in orology surgeries. The implementation of the Six Sigma program caused a significant difference in surgery cancellation (P = 0.003); 31 (3.6%) cases of cancellation were reduced to 12 (1.4%) cases. The results showed that Six Sigma program is a pre-surgery care quality improvement program. Patient education and the implementation of the 6 sigma program can be effective in reducing the rate of cancellation of operations.

MS-377, a novel selective sigma(1) receptor ligand, reverses phencyclidine-induced release of dopamine and serotonin in rat brain.

Science.gov (United States)

Takahashi, S; Horikomi, K; Kato, T

2001-09-21

A novel selective sigma(1) receptor ligand, (R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), inhibits phencyclidine (1-(1-phenylcyclohexyl)piperidine; PCP)-induced behaviors in animal models. In this study, we measured extracellular dopamine and serotonin levels in the rat brain after treatment with MS-377 alone, using in vivo microdialysis. We also examined the effects of MS-377 on extracellular dopamine and serotonin levels in the rat medial prefrontal cortex after treatment with PCP. MS-377 itself had no significant effects on dopamine release in the striatum (10 mg/kg, p.o.) nor on dopamine or serotonin release in the medial prefrontal cortex (1 and 10 mg/kg, p.o.). PCP (3 mg/kg, i.p.) markedly increased dopamine and serotonin release in the medial prefrontal cortex. MS-377 (1 mg/kg, p.o.), when administered 60 min prior to PCP, significantly attenuated this effect of PCP. These results suggest that the inhibitory effects of MS-377 on PCP-induced behaviors are partly mediated by inhibition of the increase in dopamine and serotonin release in the rat medial prefrontal cortex caused by PCP.

A Structural Molar Volume Model for Oxide Melts Part I: Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 Melts—Binary Systems

Science.gov (United States)

Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho

2016-04-01

A structural molar volume model was developed to accurately reproduce the molar volume of molten oxides. As the non-linearity of molar volume is related to the change in structure of molten oxides, the silicate tetrahedral Q-species, calculated from the modified quasichemical model with an optimized thermodynamic database, were used as basic structural units in the present model. Experimental molar volume data for unary and binary melts in the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 system were critically evaluated. The molar volumes of unary oxide components and binary Q-species, which are model parameters of the present structural model, were determined to accurately reproduce the experimental data across the entire binary composition in a wide range of temperatures. The non-linear behavior of molar volume and thermal expansivity of binary melt depending on SiO2 content are well reproduced by the present model.

A Semiempirical Model for Sigma-Phase Precipitation in Duplex and Superduplex Stainless Steels

Science.gov (United States)

Ferro, P.; Bonollo, F.

2012-04-01

Sigma phase is known to reduce the mechanical properties and corrosion resistance of duplex and superduplex stainless steels. Therefore, heat treatments and welding must be carefully performed so as to avoid the appearance of such a detrimental phase, and clearly, models suitable to faithfully predict σ-phase precipitation are very useful tools. Most fully analytical models are based on thermodynamic calculations whose agreement with experimental results is not always good, so that such models should be used for qualitative purposes only. Alternatively, it is possible to exploit semiempirical models, where time-temperature-transformation (TTT) diagrams are empirically determined for a given alloy and the continuous-cooling-transformation (CCT) diagram is calculated from the TTT diagram. In this work, a semiempirical model for σ-phase precipitation in duplex and superduplex stainless steels, under both isothermal and unisothermal conditions, is proposed. Model parameters are calculated from empirical data and CCT diagrams are obtained by means of the additivity rule, whereas experimental measurements for model validation are taken from the literature. This model gives a satisfactory estimation of σ-phase precipitates during both isothermal aging and the continuous cooling process.

N-(N-benzylpiperidin-4-yl)-2-[{sup 18}F]fluorobenzamide: A potential ligand for PET imaging of {sigma} receptors

Energy Technology Data Exchange (ETDEWEB)

Chyngyann, Shiue; Shiue, Grace G; Zhang, Sue X; Wilder, Susan; Greenberg, Joel H; Benard, Francois; Wortman, Jeffrey A; Alavi, Abass A

1997-10-01

Four nitro- and fluorobenzamides (1-4) have been synthesized in good yields from nitro- and fluoro-substituted benzoyl chloride with 4-amino-1-benzylpiperidine. In vitro studies showed that these compounds have high affinities to {sigma} receptors. N-(N-Benzylpiperidin-4-yl)-2-fluorobenzamide (3), in particular, bound to {sigma} receptors with high affinity (K{sub i} = 3.4 nM, guinea pig brain membranes) and high selectivity ({sigma}-2/{sigma}-1 = 120). It was, therefore, labeled with {sup 18}F and evaluated as a {sigma} receptor radioligand. N-(N-Benzylpiperidin-4-yl)-2-[{sup 18}F]fluorobenzamide (3a) was synthesized in one step by nucleophilic substitution of the 2-nitro precursor (1) with [{sup 18}F]fluoride in DMSO at 140 deg. C for 20 min followed by purification with HPLC in 4-10% yield (decay corrected). The synthesis time was 90 min and the specific activity was 0.4-1.0 Ci/{mu}mol. Tissue distribution in mice revealed that the uptakes of 3a in the brain, heart, liver, lungs, spleen, kidneys and small intestine were high, and the radioactivity in these organs remained constant from 60 to 120 min post-injection. The radioactivity in the bone did not significantly increase, suggesting in vivo defluorination may not be the major route of metabolism of 3a in mice. Blocking studies with haloperidol in rats indicated that the uptake of compound 3a in the rat brain was selective to haloperidol-sensitive {sigma} sites. These results suggest that compound 3a is a potent {sigma} receptor radioligand and may be a potential ligand for PET imaging of {sigma} receptors in humans.

Electromechanical behavior of [001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

Science.gov (United States)

Yan, Yongke; Wang, Yu. U.; Priya, Shashank

2012-05-01

[001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ceramics were synthesized by using templated grain growth method. Significantly high [001] texture degree corresponding to 0.98 Lotgering factor was achieved at 1 vol. % BaTiO3 template. Electromechanical properties for [001]-textured PMN-PT ceramics with 1 vol. % BaTiO3 were found to be d33 = 1000 pC/N, d31 = 371 pC/N, ɛr = 2591, and tanδ = ˜0.6%. Elastoelectric composite based modeling results showed that higher volume fraction of template reduces the overall dielectric constant and thus has adverse effect on the piezoelectric response. Clamping effect was modeled by deriving the changes in free energy as a function of applied electric field and microstructural boundary condition.

Precipitation Mechanism of Sigma Phase in Super Duplex Stainless Steels

Science.gov (United States)

Nakade, Katsuyuki; Kuroda, Toshio

The influence of alloying elements on the precipitation behavior of sigma (σ) phase was investigated for conventional SAF2205 and SAF2507 super duplex stainless steel. Time-Temperature-Precipitation (T-T-P) diagram of sigma phase of SAF2507 were shifted toward to shorter times compared to SAF2205. The precipitation of sigma phase was accelerated with increasing Cr and Mo concentration. According to the microstructure observation, the sigma phase began to precipitate at ferrite (α) ⁄ austenite (γ) phase boundaries and grew into ferrite for SAF2507 and SAF2205 steel. In the as-received condition, Cr and Mo concentration in ferrite was clearly higher than that in austenite. Especially, it was found that Mo concentration in ferrite of SAF2507 was higher than that in ferrite of SAF2205. The result of EPMA-measurement showed that sigma phase was mainly Fe-Cr-Mo intermetallic compound and Mo was significantly enriched into sigma phase. The difference of Mo concentration in ferrite significantly affected to the sigma phase precipitation. The secondary austenite formation was also induced by sigma phase precipitation. Cr and Mo were ejected to the remained ferrite ⁄ austenite phase boundaries by secondary austenite formation. Consequently, sigma phase precipitation was more accelerated by the reheating.

SIGMA WEB INTERFACE FOR REACTOR DATA APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Pritychenko,B.; Sonzogni, A.A.

2010-05-09

We present Sigma Web interface which provides user-friendly access for online analysis and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The interface includes advanced browsing and search capabilities, interactive plots of cross sections, angular distributions and spectra, nubars, comparisons between evaluated and experimental data, computations for cross section data sets, pre-calculated integral quantities, neutron cross section uncertainties plots and visualization of covariance matrices. Sigma is publicly available at the National Nuclear Data Center website at http://www.nndc.bnl.gov/sigma.

Sigma Web Interface For Reactor Data Applications

International Nuclear Information System (INIS)

Pritychenko, B.; Sonzogni, A.A.

2010-01-01

We present Sigma Web interface which provides user-friendly access for online analysis and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The interface includes advanced browsing and search capabilities, interactive plots of cross sections, angular distributions and spectra, nubars, comparisons between evaluated and experimental data, computations for cross section data sets, pre-calculated integral quantities, neutron cross section uncertainties plots and visualization of covariance matrices. Sigma is publicly available at the National Nuclear Data Center website at http://www.nndc.bnl.gov/sigma.

Modeling tritium behavior in Li{sub 2}ZrO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Billone, M C [Argonne National Lab., IL (United States). Fusion Power Program

1998-03-01

Lithium metazirconate (Li{sub 2}ZrO{sub 3}) is a promising tritium breeder material for fusion reactors because of its excellent tritium release characteristics. In particular, for water-cooled breeding blankets (e.g., ITER), Li{sub 2}ZrO{sub 3} is appealing from a design perspective because of its good tritium release at low operating temperatures. The steady-state and transient tritium release/retention database for Li{sub 2}ZrO{sub 3} is reviewed, along with conventional diffusion and first-order surface desorption models which have been used to match the database. A first-order surface desorption model is recommended in the current work both for best-estimate and conservative (i.e., inventory upper-bound) predictions. Model parameters are determined and validated for both types of predictions, although emphasis is placed on conservative design predictions. The effects on tritium retention of ceramic microstructure, protium partial pressure in the purge gas and purge gas flow rate are discussed, along with other mechanisms for tritium retention which may not be dominant in the experiments, but may be important in blanket design analyses. The proposed tritium retention/release model can be incorporated into a transient thermal performance code to enable whole-blanket predictions of tritium retention/release during cyclic reactor operation. Parameters for the ITER driver breeding blanket are used to generate a numerical set of model predictions for steady-state operation. (author)

Study of {Sigma}(1385) and {Xi}(1321) hyperon and antihyperon production in deep inelastic muon scattering

Energy Technology Data Exchange (ETDEWEB)

Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Schmidt, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Alekseev, M.G.; Birsa, R.; Bravar, A.; Dalla Torre, S.; Dasgupta, S.S.; Gobbo, B.; Sozzi, F.; Steiger, L.; Tessaro, S.; Tessarotto, F. [Trieste Section of INFN, Trieste (Italy); Alexakhin, V.Y.; Alexeev, G.D.; Efremov, A.; Gavrichtchouk, O.P.; Gushterski, R.; Guskov, A.; Ivanshin, Y.; Kroumchtein, Z.V.; Kuchinski, N.; Meshcheryakov, G.; Nagaytsev, A.; Olshevsky, A.G.; Rodionov, V.; Rossiyskaya, N.S.; Sapozhnikov, M.G.; Savin, I.A.; Shevchenko, O.Y.; Zemlyanichkina, E.; Zhuravlev, N. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexandrov, Y. [Lebedev Physical Institute, Moscow (Russian Federation); Amoroso, A.; Balestra, F.; Bertini, R.; Chiosso, M.; Garfagnini, R.; Gnesi, I.; Grasso, A.; Kotzinian, A.M.; Parsamyan, B.; Piragino, G.; Sosio, S. [University of Turin, Department of Physics (Italy); Torino Section of INFN, Turin (Italy); Austregesilo, A.; Bicker, K. [CERN, Geneva 23 (Switzerland); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Badelek, B. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Barth, J.; Bieling, J.; Goertz, S.; Klein, F.; Panknin, R.; Pretz, J.; Windmolders, R. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Baum, G. [Universitaet Bielefeld, Fakultaet fuer Physik, Bielefeld (Germany); Bedfer, Y.; Burtin, E.; Capozza, L.; Ferrero, A.; Hose, N. d' ; Kunne, F.; Magnon, A.; Marchand, C.; Morreale, A.; Neyret, D.; Platchkov, S.; Thibaud, F.; Vandenbroucke, M.; Wollny, H. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Berlin, A.; Gautheron, F.; Hess, C.; Kisselev, Y.; Koivuniemi, J.H.; Meyer, W.; Reicherz, G.; Wang, L. [Universitaet Bochum, Institut fuer Experimentalphysik, Bochum (Germany); Bernhard, J.; Harrach, D. von; Jasinski, P.; Kabuss, E.; Kang, D.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Schmiden, H. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M. [LIP, Lisbon (Portugal); Bradamante, F.; Bressan, A.; Duic, V.; Elia, C.; Giorgi, M.; Levorato, S.; Martin, A.; Sbrizzai, G.; Schiavon, P. [University of Trieste, Department of Physics (Italy); Trieste Section of INFN, Trieste (Italy); Buechele, M.; Fischer, H.; Guthoerl, T.; Heinsius, F.H.; Herrmann, F.; Koenigsmann, K.; Nerling, F.; Nowak, W.D.; Schill, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Wolbeek, J. ter [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Hoeppner, C.; Huber, S.; Ketzer, B.; Kraemer, M.; Mann, A.; Nagel, T.; Neubert, S.; Paul, S.; Schmitt, L.; Uhl, S. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Cicuttin, A.; Crespo, M.L. [Abdus Salam ICTP, Trieste (Italy); Trieste Section of INFN, Trieste (Italy); Dasgupta, S.; Sarkar, S.; Sinha, L. [Matrivani Institute of Experimental Research and Education, Calcutta (India); Denisov, O.Y.; Maggiora, A.; Takekawa, S. [Torino Section of INFN, Turin (Italy); Donskov, S.V.; Filin, A.; Khaustov, G.V.; Khokhlov, Y.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D. [State Research Center of the Russian Federation, Institute for High Energy Physics, Protvino (Russian Federation); Doshita, N.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Suzuki, H. [Yamagata University, Yamagata (Japan); Duennweber, W.; Faessler, M.; Geyer, R.; Schlueter, T.; Uman, I. [Ludwig-Maximilians-Universitaet Muenchen, Department fuer Physik, Munich (Germany); Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Zaremba, K.; Ziembicki, M. [Warsaw University of Technology, Institute of Radioelectronics, Warsaw (Poland); Finger, M.; Finger, M.; Novy, J. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Du Fresne von Hohenesche, N. [CERN, Geneva 23 (Switzerland); Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Frolov, V.; Mallot, G.K.; Rocco, E.; Schoenning, K.; Schott, M. [CERN, Geneva 23 (Switzerland); Gerassimov, S.; Konorov, I. [Lebedev Physical Institute, Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Horikawa, N. [Nagoya University, Nagoya (Japan); Jary, V.; Virius, M. [Czech Technical University in Prague, Prague (Czech Republic); Klimaszewski, K.; Kurek, K.; Rondio, E.; Sandacz, A.; Sulej, R.; Sznajder, P.; Wislicki, W. [National Centre for Nuclear Research, Warsaw (Poland); Kouznetsov, O. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Lichtenstadt, J. [Tel Aviv University, School of Physics and Astronomy, Tel Aviv (Israel); Makke, N. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); University of Trieste, Department of Physics (IT); Trieste Section of INFN, Trieste (IT); Matsuda, T. [University of Miyazaki, Miyazaki (JP); Panzieri, D. [University of Eastern Piedmont, Alessandria (IT); Polak, J. [Technical University in Liberec, Liberec (CZ); University of Trieste, Department of Physics (IT); Trieste Section of INFN, Trieste (IT); Srnka, A. [AS CR, Institute of Scientific Instruments, Brno (CZ); Sulc, M. [Technical University in Liberec, Liberec (CZ); Zavertyaev, M. [Lebedev Physical Institute, Moscow (RU)

2013-10-15

Large samples of {Lambda}, {Sigma}(1385) and {Xi}(1321) hyperons produced in the deep-inelastic muon scattering off a {sup 6}LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of {Sigma}(1385){sup +}, {Sigma}(1385){sup -}, anti {Sigma}(1385){sup -}, anti {Sigma}(1385){sup +}, {Xi}(1321){sup -}, and anti {Xi}(1321){sup +} hyperons decaying into {Lambda}(anti {Lambda}){pi} were measured. The ratios of heavy-hyperon to {Lambda} and heavy-antihyperon to anti {Lambda} were found to be in the range 3.8 % to 5.6 % with a relative uncertainty of about 10 %. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator. (orig.)