Estudo da cinética de degradação da resina benzoxazina e seus compósitos nanoestruturados

The benzoxaxine resin is a new class of thermoset phenolic resin, which is presenting, in the lasts decades, a great application in the aircraft industry due mainly to its excellent mechanical and thermal properties. This resin associates the mechanical properties of epoxy resin with the thermal and flame retardant properties of phenolic resin. In this context, they are considered polymers of high performance and they are excellent candidates to replace the current thermoset matrices used in the processing of high performance composites. Thus, in this study nanostructured composites Benzoxazine/CNT were produced at different concentrations of functionalized and non-functionalized CNT (0,1%; 0,5% and 1,0% w/w). The thermal stability of the benzoxazine resin and its nanostructured composites was studied using thermogravimetry (TGA) and degradation kinetic model Ozawa-Wall-Flynn (O-W-F). The thermal characterization also included differential scanning calorimetry (DSC) and dynamic-mechanical analysis, infrared spectroscopy with Fourier transform (FTIR) and scanning electron microscopy (SEM).The introduction of non-functionalized CNT at low concentrations resulted in nanostructured composites with better thermal properties in relation to the neat resin. For all cases, however, the dispersion of CNT in the matrix was ineffective

A (des)construção da imagem do sujeito professor na mídia: evidências da materialização de valores sociais

The main objective of this study focuses on investigate how the style of the Conhecimento Prático Língua Portuguesa magazine, from Escala publisher, reveals a materialization, in its wordings, of social values that surround our society regarding the teaching class. Besides, we thought about the construction of an other - teacher - by means of the I speech (the enunciator). Furthermore, we reflected on how happens the genre opinion article handling and whether there is, when aimed to the teaching class. All these questions were discussed under the perspective of Bakhtin's theory, focusing our analysis in the wording notions, dialogism, style and speech genres. Our analysis indicates a materialization of social values in syntactic issues and a hybridization of genres when the addressee is a teacher

Usinagem do alumínio da classe 6005 com uso de ferramenta cerâmica

The machining process is so much important in the economic world. Many machining parameters have been studied to maximize results, in terms of cost and lifetime. (decrease of cutting tool wear, improved surface finish, among others). The objective of this study is to evaluate the wear of a ceramic tool in the machining of the aluminum alloy 6005 A. The analysis of the wear of the cutting tools is very important due to its big impact on the final finishing of the piece as a whole. The evaluation took place in two stages, first it was done a detailed study of the literature of the whole machining process, where the study of the formation and swarf classification were among the most important steps in this phase. The second step consisted in the machining of the piece of aluminum 6005 A with a ceramic cutting tool constituded of aluminum oxide and magnesium oxide with silicon carbide impregnation. The swarf generated in this process was then photographed with a Zeiss optical microscope and analyzed for its size and shape. Through this comparison it was concluded that the swarf are generated shear swarfs, shaped like a tangled, fragmented and arcs connected, thus classifying the material as medium difficulty machining. Through the image analysis tool it was concluded that the parameter of lower wear was the: Vc = 500m / min, f = 0.10mm / rev and ap = 0.5mm

Reestruturação e automação de processos: caso de um processo da área de compras e suprimentos de uma empresa brasileira do setor de mídia

Innovation in the field of Information Technology (IT) have made companies evaluate their processes and activity of its supply chain to conform to this new reality. In the supply chain management, one of the tools that revolutionized the activities was the use of management information systems such as ERP tool. This system allows greater integration of data from multiple areas of the enterprise and beyond, giving more activities to processes and activities. This work aims to analyze the results and impacts of the restructuring of an equipment leasing process in a Brazilian media company and verify that the gains and improvements that were targeted in the initial design of this restructuring have been achieved. Also the risks identified with this change will be studied, the reactions of those involved in this process and the performance of the chain as a whole. To carry out this work was carried out a single case study with data collection in the assessed company and literature related to supply chain and information systems