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Módulo elástico como ferramenta para o acompanhamento de transformações in situ e desenvolvimento de concretos refratários
(Universidade Federal de São Carlos, 2012-09-12) Souza, Tiago Marcolino de; Pandolfelli, Victor Carlos; https://lattes.cnpq.br/7369376873984839; https://lattes.cnpq.br/6302194006113059
Refractory castables are multiphase materials usually exhibiting complex heterogeneous microstructures, which have their mechanical strength affected by chemical and structural changes. These microstructural changes directly affect the Young s modulus, as this property is strongly dependent on the chemical bonds, crystalline structure and flaws, such as porosity and cracks. For the Al2O3-MgO system, two transformations can be highlighted: the volumetric expansion associated with the magnesia hydration and the in situ spinel formation, both can play a role by increasing or decreasing the castable s embrittlement depending on the resulting expansion. Considering this aspect, the addition of MgO sources with different reactivity in refractory castables was evaluated during curing and drying steps. As a result, different routes for magnesia s sources addition to the castables, without the usual damage caused by MgO hydration, are presented in this work. The addition of acetic acid sped up the brucite precipitation, inducing the formation of a resilient structure able to inhibit the stresses generation. Additionally, the effect of mineralizing or densification compounds on spinel-forming castables and the microstructural evolution of refractory castables containing different MgO sources, colloidal binders or high-carbon content were assessed during the thermal treatment by hot Young s modulus measurements using the resonance bar technique. The attained results highlight the technique s broad feature and accuracy for the development of refractory materials. The MgF2 and magnesium borate addition sped up the spinel formation, whereas TiO2 led to lower expansion values and greater rigidity at high temperatures, all of them as promising alternatives to master the castable s microstructure design. For the nano-bonded castables, the sintering additive addition further enhanced the Young s modulus resulting in high-performance refractories. Additionally, the elastic modulus measurements were able to evaluate the antioxidants effect in high-carbon containing castables and to identify the mechanisms of crack healing (during heating) and opening (during cooling).
Monitoramento de Ambientes Virtuais Distribuídos com suporte a clientes sob projeção única e multiprojeção
(Universidade Federal de São Carlos, 2012-09-12) Penteado, Maurício Giacomini; Trevelin, Luis Carlos; https://lattes.cnpq.br/5082419783043736; https://lattes.cnpq.br/3558493336659272
Immersive, interactive, and collaborative distributed applications, due to their real time and multi-platform characteristics, require a monitoring structure of their functionalities during the development period, which is not fully available in the current monitoring systems, which are usually specific of the languages and platforms in which they are made available. Monitoring systems that require synchronism of distributed objects during the processing is a complex task. Especially in distributed systems from multi-projection where timing is critical to its operation. It is often difficult to check the correct execution of the system. It might be useful for developers and users of such systems to have the ability of identifying, for example, if the reason for the system delay is due to the abusive use of a resource or due to programming mistakes; the identification of which object has crashed, compromising the system as a whole. Distributed object systems, also known as SOA (Service Oriented Architecture), generally use middleware of the broker type in their infrastructure and can have a dynamic number of connected clients or servers when running. There are, in the literature, several tools for the monitoring of performance, resources, debugging, and support, among others, of such systems. Nevertheless, the tools available in the literature are limited to programming languages or platforms that are able to process the monitoring agents related to them. In this work, a tool for the monitoring of distributed object systems is proposed, based on communication described in XML documents, which allows language and platform independence in the such systems development. A structure for the design of tools for the monitoring of distributed object systems is proposed, based on communication described in XML documents, which allows language and platform independence in the such systems development. In addition to the structure that is theoretically founded, the conception of a tool is structured in the manner described and proven in monitoring data from a case study.