Measurement of the ratio of inclusive cross sections sigma(p(p)over-bar -> Z plus b-quark jet)/sigma(p(p)over-bar -> Z plus jet) at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A theoretical study of the A(2)Sigma(+)-X-2 Pi system of the SiP molecule

The A (2)Sigma(+) and X(2)Pi electronic states of the SiP species have been investigated theoretically at a very high level of correlation treatment (CASSCF/MRSDCI). Very accurate potential energy curves are presented for both states, as well as the associated spectroscopic constants as derived from the vib-rotational energy levels determined by means of the numerical solution of the radial Schrodinger equation. Electronic transition moment function, oscillator strengths, Einstein coefficients for spontaneous emission, and Franck-Condon factors for the A(2)Sigma(+)-X(2)Pi system have been calculated. Dipole moment functions and radiative lifetimes for both states have also been determined. Spin-orbit coupling constants are also reported. The radiative lifetimes for the A(2)Sigma(+) state, taking into account the spin-orbit diagonal correction to the X(2)Pi state, decrease from a value of 138 ms at v' = 0 to 0.48 ms at v' = 8, and, for the X(2)Pi state, from 2.32 s at v = 1 to 0.59 s at v = 5. Vibrational and rotational transitions are expected to be relatively strong.

Contribuições do Seis Sigma: estudos de caso em multinacionais

A literatura sugere que o Seis Sigma trouxe contribuições sob vários aspectos, tanto no âmbito da gestão da qualidade como também da gestão estratégica. No entanto, ainda há certa escassez de informações sobre esse assunto no cenário organizacional brasileiro. Este artigo visa reduzir essa carência da literatura, mostrando uma visão prática sobre as contribuições decorrentes dos investimentos no Seis Sigma para empresas do Brasil. A relevância de requisitos essenciais - como conceito de qualidade; combinação das abordagens estatística e estratégica; sistematização metodológica; formação de especialistas; e gestão de projetos - é discutida tanto em âmbito teórico-conceitual como prático. O método do estudo de caso foi aplicado para obter o embasamento empírico da pesquisa. Os investimentos no Seis Sigma feitos por duas subsidiárias brasileiras de empresas multinacionais norte-americanas (uma de manufatura e uma de serviços) são apresentados e reforçam a relevância dos requisitos supracitados.

Modelo de referência para estruturar o Seis Sigma nas organizações

Este artigo apresenta o modelo de referência para estruturar o Seis Sigma, o qual é resultante da incorporação de teorias que contribuem para aumentar o potencial estratégico do Seis Sigma no sentido de incrementar o desempenho organizacional. em sua proposta, o modelo de referência engloba um direcionamento sobre certos requisitos primordiais para o sucesso do programa Seis Sigma. A base teórica de sustentação do modelo de referência foi construída a partir de estudos sobre a influência dos seguintes fatores: orientação estratégica e alinhamento estratégico; medição e gerenciamento do desempenho organizacional; uso de estatística (pensamento estatístico); capacitação/especialização de pessoas; implementação e gerenciamento de projetos; e uso de tecnologia de informação. Complementando a proposição do modelo, o artigo traz evidências empíricas acerca da contribuição dos fatores identificados na formulação do modelo de referência, expondo resultados decorrentes de estudos de caso realizados em quatro subsidiárias brasileiras de multinacionais de grande porte. A análise dos dados forneceu evidências positivas de que os fatores mencionados influenciam de forma efetiva o sucesso e a consolidação do Seis Sigma nas empresas estudadas.

Ghost poles in the nucleon propagator in the linear sigma model approach and its role in pi N low-energy theorems

Complex mass poles, or ghost poles, are present in the Hartree-Fock solution of the Schwinger-Dyson equation for the nucleon propagator in renormalizable models with Yukawa-type meson-nucleon couplings, as shown many years ago by Brown, Puff and Wilets (BPW), These ghosts violate basic theorems of quantum field theory and their origin is related to the ultraviolet behavior of the model interactions, Recently, Krein et.al, proved that the ghosts disappear when vertex corrections are included in a self-consistent way, softening the interaction sufficiently in the ultraviolet region. In previous studies of pi N scattering using ''dressed'' nucleon propagator and bare vertices, did by Nutt and Wilets in the 70's (NW), it was found that if these poles are explicitly included, the value of the isospin-even amplitude A((+)) is satisfied within 20% at threshold. The absence of a theoretical explanation for the ghosts and the lack of chiral symmetry in these previous studies led us to re-investigate the subject using the approach of the linear sigma-model and study the interplay of low-energy theorems for pi N scattering and ghost poles. For bare interaction vertices we find that ghosts are present in this model as well and that the A((+)) value is badly described, As a first approach to remove these complex poles, we dress the vertices with phenomenological form factors and a reasonable agreement with experiment is achieved, In order to fix the two cutoff parameters, we use the A((+)) value for the chiral limit (m(pi) --> 0) and the experimental value of the isoscalar scattering length, Finally, we test our model by calculating the phase shifts for the S waves and we find a good agreement at threshold. (C) 1997 Elsevier B.V. B.V.

THE ALGEBRA OF NONLOCAL CHARGES IN NONLINEAR SIGMA-MODELS

We obtain the exact classical 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. We generalize the results for the presence of a Wess-Zumino term. The algebra is very similar to the previous one, now containing a calculable correction of order one unit lower. The relation with Yangians and the role of the results in the context of Lie-Poisson algebras are also discussed.

Measurement of the differential cross section d sigma/dt in elastic p(p)over-bar scattering at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bound state solution of the grassmannian nonlinear sigma model with fermions

We construct the S-matrix for bound state (gauge-invariant) scattering for nonlinear sigma models defined on the manifold SU(n) S(U(p)⊗U(n-p)) with fermions. It is not possible to compute gauge non-singlet matrix elements. In the present language, constraints from higher conservation laws determine the bound state solution. An alternative derivation is also presented. © 1988.

N = 2 sigma models for Ramond-Ramond backgrounds

Using the U(4) hybrid formalism, manifestly N = (2,2) worldsheet supersymmetric sigma models are constructed for the type-IIB superstring in Ramond-Ramond backgrounds. The Kahler potential in these N = 2 sigma models depends on four chiral and antichiral bosonic superfields and two chiral and antichiral fermionic superfields. When the Kahler potential is quadratic, the model is a free conformal field theory which describes a flat ten-dimensional target space with Ramond-Ramond flux and non-constant dilaton. For more general Kahler potentials, the model describes curved target spaces with Ramond-Ramond flux that are not plane-wave backgrounds. Ricci-flatness of the Kahler metric implies the on-shell conditions for the background up to the usual four-loop conformal anomaly. © SISSA/ISAS 2002.

Environmental management and operational performance in automotive companies in Brazil: The role of human resource management and lean manufacturing

The main objective of this study is to verify the influence of Environmental Management (EM) on Operational Performance (OP) in Brazilian automotive companies, analyzing whether Lean Manufacturing (LM) and Human Resources (HR) interfere in the greening of these companies. Therefore, a conceptual framework listing these concepts was proposed, and three research hypotheses were presented. A questionnaire was elaborated based on this theoretical background and sent to respondents occupying the highest positions in the production/operations areas of Brazilian automotive companies. The data, collected from 75 companies, were analyzed using structural equation modeling. The main results are as follows: (a) the model tested revealed an adequate goodness of fit, showing that overall, the relations proposed between EM and OP and between HR, LM and EM tend to be statistically valid; (b) EM tends to influence OP in a positive and statistically weak manner; (c) LM has a greater influence on EM when compared to the influence HR has over EM; (d) HR has a positive relationship over EM, but the statistical significance of this relationship is less than that of the other evaluated relationships. The originality of this paper lies in its gathering the concepts of EM, LM, HR and OP in a single study, as they generally tend not to be treated jointly. This paper also provided valid empirical evidence for a littlestudied context: the Brazilian automotive sector. © 2012 Elsevier Ltd. All rights reserved.

Lean and green? Evidências empíricas do setor automotivo brasileiro

The aim of this paper is to verify whether the practices of lean manufacturing are positively associated with the adoption of environmental management practices in Brazilian companies in the automotive sector to test the hypothesis that by being lean the business tends to become green. To this purpose, a framework associating these concepts with the research hypothesis was proposed. The data collected from 75 companies were analyzed using Structural Equation Modeling. The main results show that lean manufacturing (LM) is positively associated with environmental management (EM), but the explanation power of LM over EM is considered weak/moderate. In fact, being lean also means being green, but other organizational variables not considered in this study may influence the greening of organizations.

Integralismo e ideologia autocrática chauvinista regressiva: crítica aos herdeiros do sigma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do processo de gestão de portfólio de projetos seis sigma em indústrias brasileiras do setor automotivo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aumento da produtividade: utilizando a metodologia Six Sigma e Lógica Fuzzy, um estudo de caso em uma empresa do Pólo Industrial de Manaus – PIM

Este trabalho utiliza a metodologia six sigma com o objetivo de aumentar a produtividade da Linha de LCD (Liquid Crystal Display) em uma fábrica do Pólo Industrial de Manaus - PIM e um sistema de inferência fuzzy para mensurar o aumento dessa produtividade, onde foram identificados vários parâmetros baseados na metodologia six sigma. Dentre os quais, conforme grau de relevância dos especialistas deste estudo, pode-se destacar: desperdícios, capacidade produtiva e estudo de tempos. Ressaltando ainda que o sistema proposto seja de grande importância para profissionais e pesquisadores da gestão da produção, os quais desejam resultados que reduzam custos e conseqüentemente aumente os lucros da organização.