Dyonic Integrable Models

A class of non abelian affine Toda models arising from the axial gauged two-loop WZW model is presented. Their zero curvature representation is constructed in terms of a graded Kac-Moody algebra. It is shown that the discrete multivacua structure of the potential together with non abelian nature of the zero grade subalgebra allows soliton solutions with non trivial electric and topological charges. The dressing transformation is employed to explicitly construct one and two soliton solutions and their bound states in terms of the tau functions. A discussion of the classical spectra of such solutions and the time delays are given in detail.Comment: Latex 30 pages, corrected some typo

T-duality of axial and vector dyonic integrable models

A general construction of affine Non Abelian (NA) - Toda models in terms of axial and vector gauged two loop WZNW model is discussed. They represent {\it integrable perturbations} of the conformal $\sigma$-models (with tachyons included) describing (charged) black hole type string backgrounds. We study the {\it off-critical} T-duality between certain families of axial and vector type of integrable models for the case of affine NA- Toda theories with one global U(1) symmetry. In particular we find the Lie algebraic condition defining a subclass of {\it T-selfdual} torsionless NA Toda models and their zero curvature representation.Comment: 20 pages, latex, no figures,improvments in the text of Sects.1,2 and 6;typos corrected,references added, to appear in Ann. of Physics (NY

Multicharged Dyonic Integrable Models

We introduce and study new integrable models of A_n^{(1)}-Non-Abelian Toda type which admit U(1)\otimes U(1) charged topological solitons. They correspond to the symmetry breaking SU(n+1) \to SU(2)\otimes SU(2)\otimes U(1)^{n-2} and are conjectured to describe charged dyonic domain walls of N=1 SU(n+1) SUSY gauge theory in large n limit. It is shown that this family of relativistic IMs corresponds to the first negative grade q={-1} member of a dyonic hierarchy of generalized cKP type. The explicit relation between the 1-soliton solutions (and the conserved charges as well) of the IMs of grades q=-1 and q=2 is found. The properties of the IMs corresponding to more general symmetry breaking SU(n+1) \to SU(2)^{\otimes p}\otimes U(1)^{n-p} as well as IM with global SU(2) symmetries are discussed.Comment: 48pages, latex, v2. typos in eqns. (1.7) and (3.20) corrected, small improvements in subsection 2.2, new reference added;v3. improvements in text of Sect. 1,2 and 6; new Sect 7 and new refs. added; version to appear in Nucl. Phys.

T-duality in Massive Integrable Field Theories: The Homogeneous and Complex sine-Gordon Models

The T-duality symmetries of a family of two-dimensional massive integrable field theories defined in terms of asymmetric gauged Wess-Zumino-Novikov-Witten actions modified by a potential are investigated. These theories are examples of massive non-linear sigma models and, in general, T-duality relates two different dual sigma models perturbed by the same potential. When the unperturbed theory is self-dual, the duality transformation relates two perturbations of the same sigma model involving different potentials. Examples of this type are provided by the Homogeneous sine-Gordon theories, associated with cosets of the form G/U(1)^r where G is a compact simple Lie group of rank r. They exhibit a duality transformation for each element of the Weyl group of G that relates two different phases of the model. On-shell, T-duality provides a map between the solutions to the equations of motion of the dual models that changes Noether soliton charges into topological ones. This map is carefully studied in the complex sine-Gordon model, where it motivates the construction of Bogomol'nyi-like bounds for the energy that provide a novel characterisation of the already known one-solitons solutions where their classical stability becomes explicit.Comment: 29 pages, LaTe

T-Duality in 2-D Integrable Models

The non-conformal analog of abelian T-duality transformations relating pairs of axial and vector integrable models from the non abelian affine Toda family is constructed and studied in detail.Comment: 14 pages, Latex, v.2 misprints corrected, reference added, to appear in J. Phys.

The complex Sine-Gordon equation as a symmetry flow of the AKNS Hierarchy

It is shown how the complex sine-Gordon equation arises as a symmetry flow of the AKNS hierarchy. The AKNS hierarchy is extended by the ``negative'' symmetry flows forming the Borel loop algebra. The complex sine-Gordon and the vector Nonlinear Schrodinger equations appear as lowest negative and second positive flows within the extended hierarchy. This is fully analogous to the well-known connection between the sine-Gordon and mKdV equations within the extended mKdV hierarchy. A general formalism for a Toda-like symmetry occupying the ``negative'' sector of sl(N) constrained KP hierarchy and giving rise to the negative Borel sl(N) loop algebra is indicated.Comment: 8 pages, LaTeX, typos corrected, references update

Vertex Operators and Soliton Solutions of Affine Toda Model with U(2) Symmetry

The symmetry structure of non-abelian affine Toda model based on the coset $SL(3)/SL(2)\otimes U(1)$ is studied. It is shown that the model possess non-abelian Noether symmetry closing into a q-deformed $SL(2)\otimes U(1)$ algebra. Specific two vertex soliton solutions are constructed.Comment: 17 pages, latex, misprints corrected, version to appear in J.Phys

Coronal microleakage of endodontically treated teeth with intracanal post exposed to fresh human saliva

OBJECTIVE: The aim of this study was to investigate the coronal microleakage of endodontically treated teeth prepared to receive an intracanal post and teeth with an intracanal post but without a prosthetic crown and exposed to contamination by fresh human saliva. MATERIAL AND METHODS: A mechanical-chemical preparation following the step-back technique was carried out in 35 extracted single-rooted human teeth. The teeth were randomly divided into five groups: G1=root canals instrumented, obturated, and prepared to receive an intracanal post (N=10); G2=root canals with cemented posts but without coronal sealing (N=10); PC1=positive control root canals instrumented and open (N=5); PC2=positive control 2 root canals without instrumentation and open (N=5); and NC=negative control healthy teeth (N=5). The crowns were removed except for the control group of intact teeth. The root canals were obturated and sterilized with cobalt 60 gamma irradiation and were then adapted in an apparatus using a Brain Heart Infusion (BHI) medium and fresh human saliva for contamination. Microbial growth was indicated by the presence of turbidity in the BHI liquid medium. RESULTS: Data were submitted to the Kaplan-Meier Survival Analysis and the Holm-Sidak statistic method, which observed an index of 90% of microleakage in root canals after 24 hours for G1 and 70% of microleakage in samples at the end of 40 days for G2. CONCLUSION: The results show that root canals with an intracanal post but without a prosthetic crown can be recontaminated when exposed to fresh human saliva in a short period

Piezoelectric co-axial filaments produced by co-extrusion of poly(vinylidene fluoride) and electrically conductive inner and outer layers

Article first published online: 3 APR 2014 : http://onlinelibrary.wiley.com/doi/10.1002/app.40710/abstract. DOI 10.1002/app.40710.The development of new thermoplastic polymer-based piezoelectric sensors with filament geometry is described. These filaments are appropriate for integration into textiles and provide new possibilities in the design and development of low cost flexible sensors produced at high rates. The developed three-layered piezoelectric monofilaments have been produced by co-extrusion using poly(vinylidene fluoride) and two different polypropylene-based electrically conductive polymers. Filaments with about 800 µm diameter, producing electrical signals proportional to the mechanical deformation applied, were obtained. The signal output has been found adequate for straightforward use with conventional piezoelectric signal conditioning systems. One of the conductive polymers tested allowed better filament geometry and process stability. This paper describes the co-extrusion production process and the results obtained in the electromechanical tests performed.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) by project PTDC/CTM/108801/2008 | FCOMP-01-0124-FEDER-009480 and in the framework of the Strategic Project PEst-C/FIS/UI607/20112011, PEst-C/CTM/LA0025/2013 (Strategic Project - LA 25 - 2013-2014) and PEst-C/CTM/UI0264/2011. Authors also thank the project Matepro –Optimizing Materials and Processes”, ref. NORTE-07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 – O Novo Norte), under the “Quadro de Referência Estratégico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER

Salmonella enterica prevalence, serotype diversity, antimicrobial resistance and control in the European pork production chain

Background: A risk assessment conducted by EFSA identified Salmonella enterica (Salmonella) as a high-risk hazard at the EU level in the context of meat inspection of swine. Despite pork being considered an important source of S. Typhimurium and its monophasic variant, Regulation (EC) No 2073/2005 does not set criteria for specific Salmonella serotypes. Enforcing specific criteria for Salmonella target serotypes could result in a reduction in the prevalence of Salmonella in the pork production chain, as has happened in broiler flocks. Scope and approach: This study gives an overview of Salmonella enterica in the European pork chain, discussing prevalence, serotype diversity, antimicrobial resistance and epidemiological importance during the last 20 years. Additionally, future trends and recommendations regarding control of Salmonella in the European pork production chain are introduced. Key findings and conclusions: The highest proportions of Salmonella-positive samples were observed at the fattening pig farm level, whereas the prevalence of Salmonella on pig carcasses was much lower. Among epidemiologically important serotypes, isolates of S. Typhimurium, and its monophasic variant were found to be resistant to ampicillin, sulfamethoxazole, streptomycin and tetracycline. Future Salmonella control in the pork production chain can preferably be conducted through a risk-based meat safety assurance system. In conclusion, a fit-for-purpose strategy applied to the pork production chain and adapted to the national epidemiological situation can deliver acceptable consumer safety