Fermion masses in a model for spontaneous parity breaking

In this paper we discuss a left-right symmetric model for elementary particles and their connection with the mass spectrum of elementary fermions. The model is based on the group $SU(2)_L\otimes SU(2)_R\otimes U(1)$. New mirror fermions and a minimal set of Higgs particles that breaks the symmetry down to $U(1)_{em}$ are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations. An important consequence of the model is that the connection between the left and right sectors can be done by the neutral vector gauge bosons Z and a new heavy Z'.Comment: 7 pages, 3 figures. Accepted in Eur. Phys. J.

Procedimento de operação, manutenção e verificação de thermomixer.

bitstream/CENARGEN/29576/1/ct060.pd

Key performance indicators for improving a CRM implementation

This document analyses the main pros and cons factors in the implementation and configuration of instances of a Customer Relationship Management tool (CRM) in a company, with the purpose of understanding if the establishment of key performance indicators (KPIs) could help achieving a higher success rate in its implantation on a new business.info:eu-repo/semantics/acceptedVersio

Procedimento de operação, manutenção e verificação da centrífuga refrigerada de bancada Eppendorf, Modelo 5810 R.

bitstream/CENARGEN/29583/1/ct063.pd

Procedimento de operação, manutenção e verificação da estufa ELETROLAB modelo 112FC.

bitstream/CENARGEN/29586/1/ct065.pd

Dynamical complexity of discrete time regulatory networks

Genetic regulatory networks are usually modeled by systems of coupled differential equations and by finite state models, better known as logical networks, are also used. In this paper we consider a class of models of regulatory networks which present both discrete and continuous aspects. Our models consist of a network of units, whose states are quantified by a continuous real variable. The state of each unit in the network evolves according to a contractive transformation chosen from a finite collection of possible transformations, according to a rule which depends on the state of the neighboring units. As a first approximation to the complete description of the dynamics of this networks we focus on a global characteristic, the dynamical complexity, related to the proliferation of distinguishable temporal behaviors. In this work we give explicit conditions under which explicit relations between the topological structure of the regulatory network, and the growth rate of the dynamical complexity can be established. We illustrate our results by means of some biologically motivated examples.Comment: 28 pages, 4 figure

Magnetism and Electronic Correlations in Quasi-One-Dimensional Compounds

In this contribution on the celebration of the 80th birthday anniversary of Prof. Ricardo Ferreira, we present a brief survey on the magnetism of quasi-one-dimensional compounds. This has been a research area of intense activity particularly since the first experimental announcements of magnetism in organic and organometallic polymers in the mid 80s. We review experimental and theoretical achievements on the field, featuring chain systems of correlated electrons in a special AB2 unit cell structure present in inorganic and organic compounds