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Colisões atômicas controladas em eletrodinâmica quântica de cavidades : emaranhamento como medida da classicalidade do campo de radiação
(Universidade Federal de São Carlos, 2009-08-12) Gama, Otávio Fabris; Villas-Bôas, Celso Jorge; https://lattes.cnpq.br/5700887540085418; https://lattes.cnpq.br/9914995130055228
In this dissertation we presente a study on the entanglement between two identical and noninteracting two-level atoms, generated by their interaction with only a singl cavity filed mode. We also show how to calculate the intensity of correlation between thes atoms by Concurrence. Besides, was show the entanglement evolution for different field states and parameters for these states in two intaraction regimes: ressonant and dispersive, showing numerically how the maximum entanglement evolves form one regime to other for each cavity filed state. We are also abble to identify wich parameters influence the intensity and shape of entanglement, allowing us to define a non-classicality criterion for the radiation field.
Determinação voltamétrica de analitos de interesse farmacêutico utilizando um eletrodo de diamante dopado com boro
(Universidade Federal de São Carlos, 2009-08-12) Sartori, Elen Julciléia Romão; Fatibello Filho, Orlando; https://lattes.cnpq.br/9859737944357808; https://lattes.cnpq.br/4436300782833384
The development of electroanalytical procedures for acetylsalicylic acid (ASA), propranolol (PROP), atenolol and sildenafil (Viagra®) in pharmaceutical formulations using a boron doped diamond (BDD) electrode, square wave and differential pulse voltammetric techniques are described. ASA was directly determined in a 0.01 mol L-1 H2SO4 solution without the need of a previous alkaline hydrolysis step with the BDD electrode and square wave voltammetry (SWV). The analytical curve was linear in the ASA concentration range 2.5 × 10-6 to 1.0 × 10-4 mol L-1 with a detection limit of 2.0 × 10-6 mol L-1. Then, the analytical determination of PROP was carried out in a 0.1 mol L-1 H2SO4 solution using a cathodically pre-treated BDD electrode employing SWV. The analytical curve was linear in the PROP concentration range 2.0 × 10-7 to 9.0 × 10-6 mol L-1 with a detection limit of 1.8 × 10-7 mol L-1. The determination of atenolol was accomplished in 0.5 mol L-1 NaNO3 (pHcond 1.1 adjusted with concentrated HNO3) on a cathodically pre-treated BDD electrode employing SWV. The analytical curve was linear in the atenolol concentration range from 2.0 × 10-6 to 4.1 × 10-5 mol L-1 with a detection limit of 9.3 × 10-7 mol L-1. Finally, a procedure for the determination of sildenafil in 0.1 mol L-1 H2SO4 on a cathodically pre-treated BDD electrode employing differential pulse voltammetry was developed. The analytical curve was linear in the sildenafil concentration range 7.3 × 10-7 to 7.3 × 10-6 mol L-1 with a detection limit of 4.8 × 10-7 mol L-1.
Efeito dos materiais do backing bar na geometria e dureza de juntas soldadas por FSW em ligas de alumínio 6013 e 2024
(Universidade Federal de São Carlos, 2009-08-12) Rosales, Marcio José Cuccolo; Alcântara, Nelson Guedes de; https://lattes.cnpq.br/3123107570992184; https://lattes.cnpq.br/4022439112683922
Solid-state joining techniques such as Friction Stir Welding (FSW) are a natural choice to produce weld low heat input, limited slight distortion and low microstructural and mechanical degradation. Great effort has currently been devoted to the joining of Al-Cu-Mg and the Al-Mg-Si alloys because of their high strength, improved formability, and application in airframe structures. FSW is a continuous, hot shear, autogenous process involving a non-consumable and rotating tool plunged between two abutting workpieces. Classical or single sided friction stir welds utilize a steel backing bar, to support the workpieces but also to prevent material loss from the join. The backing bar plays an important role in heat transfer from the joint or stir zone, which can influence the weld microstructure as well as the consolidation of material in the root of the join. The influence of backing bar material on stir zone formation has been poorly investigated in the literature. This study aims at investigating issues concerning heat transfer and plastic deformation within the stir zone of friction stir welded aircraft aluminum alloys. This study has provided clear evidence that heat transfer conditions differ in accordance to alloy type (composition), process parameters during FSW and backing bar material. The influence of heat flow on mechanical properties and microstructural characteristics of the friction stir welded joints is primarily in response to the alloys resistance to plastic deformation. Thus this is the main cause why slip or stick occurs during contact of the tool with material in viscoplastic flow. For the FSW of the 2024-T351 alloy a slip condition dominates, while in the case of friction stir welds produced in the 6013-T6 alloy stick occurs in the interface of tool.