How the Polyakov loop and the regularization affect strangeness and restoration of symmetries at finite T

The effects of the Polyakov loop and of a regularization procedure that allows the presence of high momentum quark states at finite temperature is investigated within the Polyakov-loop extended Nambu--Jona-Lasinio model. The characteristic temperatures, as well as the behavior of observables that signal deconfinement and restoration of chiral and axial symmetries, are analyzed, paying special attention to the behavior of strangeness degrees of freedom. We observe that the cumulative effects of the Polyakov loop and of the regularization procedure contribute to a better description of the thermodynamics, as compared with lattice estimations. We find a faster partial restoration of chiral symmetry and the restoration of the axial symmetry appears as a natural consequence of the full recovering of the chiral symmetry that was dynamically broken. These results show the relevance of the effects of the interplay among the Polyakov loop dynamics, the high momentum quark sates and the restoration of the chiral and axial symmetries at finite temperature.Comment: Talk given at XIII International Conference on Hadron Spectroscopy (Hadron 2009), Tallahassee, Florida, USA, 29 Nov - 4 Dec, 200

An approach to enacting business process models in support of the life cycle of integrated manufacturing systems

The complexity of enterprise engineering processes requires the application of reference architectures as means of guiding the achievement of an adequate level of business integration. This research aims to address important aspects of this requirement by associating the formalism of reference architectures to various life cycle phases of integrating manufacturing systems (IMS) and enabling their use in addressing contemporary system engineering issues. In pursuit of this aim, the following research activities were carried out: (1) to devise a framework which supports key phases of the IMS life cycle and (2) to populate part of this framework with an initial combination of architectures which can be encapsulated into a computer-aided systems engineering environment. This has led to the creation of a workbench capable of providing support for modelling, analysis, simulation, rapid-prototyping, configuration and run-time operation of an IMS, based on a consistent set of models associated with the engineering processes involved. The research effort concentrated on selecting and investigating the use of appropriate formalisms which underpin a selection of architectures and tools (i. e. CIM-OSA, Petrinets, object-oriented methods and CIM-BIOSYS), this by designing, implementing, applying and testing the workbench. The main contribution of this research is to demonstrate that it is possible to retain an adequate level of formalism, via computational structures and models, which extend through the IMS life cycle from a conceptual description of the system through to actions that the system performs when operating. The underlying methodology which supported this contribution is based on enacting models of system behaviour which encode important coordination aspects of manufacturing systems. The strategy for demonstrating the incorporation of formalism to the IMS life cycle was to enable the aggregation into a workbench of knowledge of 'what' the system is expected to achieve (i. e. 'problems' to be addressed) and 'how' the system can achieve it (i. e possible 'solutions'). Within the workbench, such a knowledge is represented through an amalgamation of business process modelling and object-oriented modelling approaches which, when adequately manipulated, can lead to business integration

Potencial agrícola do solo para o cultivo da cebola.

No Nordeste, o cultivo da cebola é realizado durante o ano todo, com concentração de plantio nos meses de janeiro a março e colheitas de maio a julho (120 dias), para atender à demanda dos mercados consumidores das regiões Sul e Sudeste

Potencial agrícola do solo para o cultivo da melancia.

A melancia (Citrullus lanatus (Thunb.)Matsum & nakai), pertence à família das cucurbitáceas, sendo originária do continente africano. É uma planta anual, de crescimento rasteiro, com várias ramificações que alcançam até 5 m de comprime nto. É cultivada em vários países do mundo, com uma produção total de, aproximadamente, 47 milhões de toneladas de frutos (Doorenbos & Kassam, 1994). No Brasil segundo dados Agrianual (2004), a área plantada em 2000 superou 80.000 ha, com produção total de 2.267.880 toneladas de frutos e rendimento da ordem de 28 t/ha, sendo o Nordeste responsável por 35,17% dessa produção destacando-se os Estados da Bahia (427.720 t),. Pernambuco (122.360 t) e Maranhão (94.020 t). A cultura da melancia tem grande importância socio-econômica no Nordeste brasileiro, por ser cultivada principalmente por pequenos agricultores, sob condições irrigadas e de chuva, devido ao seu fácil manejo e menor custo de produção, quando comparada a outras hortaliças

Potencial agrícola do solo para cultivo da melancia.

A cultura da melancia tem grande importância socio-econômica no Nordeste brasileiro, por ser cultivada principalmente por pequenos agricultores, sob condições irrigadas e de chuva, devido ao seu fácil manejo e menor custo de produção, quando comparada a outras hortaliças

Numerical simulation of the internal plasma dynamics of post-flare loops

We integrate the MHD ideal equations of a slender flux tube to simulate the internal plasma dynamics of coronal post-flare loops. We study the onset and evolution of the internal plasma instability to compare with observations and to gain insight into physical processes and characteristic parameters associated with flaring events. The numerical approach uses a finite-volume Harten-Yee TVD scheme to integrate the 1D1/2 MHD equations specially designed to capture supersonic flow discontinuities. We could reproduce the observational sliding down and upwardly propagating of brightening features along magnetic threads of an event occurred on October 1st, 2001. We show that high--speed downflow perturbations, usually interpreted as slow magnetoacoustic waves, could be better interpreted as slow magnetoacoustic shock waves. This result was obtained considering adiabaticity in the energy balance equation. However, a time--dependent forcing from the basis is needed to reproduce the reiteration of the event which resembles observational patterns -commonly known as quasi--periodic pulsations (QPPs)- which are related with large scale characteristic longitudes of coherence. This result reinforces the interpretation that the QPPs are a response to the pulsational flaring activity.Comment: Accepted MNRAS, 10 pages, 14 figures, 1 tabl

A Deformation Quantization Theory for Non-Commutative Quantum Mechanics

We show that the deformation quantization of non-commutative quantum mechanics previously considered by Dias and Prata can be expressed as a Weyl calculus on a double phase space. We study the properties of the star-product thus defined, and prove a spectral theorem for the star-genvalue equation using an extension of the methods recently initiated by de Gosson and Luef.Comment: Submitted for publicatio