Caracterização morfológica da corrosão por pite da liga AL2024 em soluções contendo cloretos e molibdatos

A very new method application for digital image processing and analysis to classify shape and evaluate size and morphology parameters of pit corrosion is used in this paper. This method seems to be very effective to analysis surfaces with low or high degree of pitting formation. Pits formed on 2024 alloy surface by chloride and by chloride + molibdate anions have similar mean area, are found to be widther than deeper and exhibit predominantly conical or near-conical and irregular geometries.

Estudo das características morfológicas dos pites nos materiais resistentes à corrosão

This paper has as a purpose a new alternative technique development to characterize pitting corrosion evolution, aiming classification, size and determination of morphological parameters which rule pits increase. In this case, the method will be applied to the 304 ABNT stainless steel, thermally treated and exposed to different times in salt spray. Different 304 steel conditions, rolled and thermally treated have exhibited similar geometry, predominantly conic, near-conic and irregular pits. On rolled steel, pits width increases faster than height; however, on thermally treated steel, pits are found to increase in height.

Análise térmica do processo de incineração de resíduos aquosos com chamas enriquecidas

The use of oxygen to enrich the combustion air can be an attractive technique to increase capacity of an incinerator originally designed to operate with air. If incinerator parameters such as operation temperature, turbulence level and residence time are fixed for a certain fuel supply rate, it is possible to increase the residue consumption rate using enriched air. This paper presents the thermal analysis for operation with enriched air of an aqueous residue experimental incinerator. The auxiliary fuel was diesel oil. The theoretical results showed that there is a considerable increase in the incineration ratio up to approximately 50 % of O 2 in the oxidiser. The tendency was confirmed experimentally. Thermal analysis was demonstrated to be an important tool to predict possible incinerator capacity increase.

Eficácia das terapias convencionais (Pentoxifilina e Nicotinamida/Alopurinol) comparadas a metilprednisolona intravenosa no tratamento da oftalmopatia de Graves

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Comportamentos e situações de risco e de segurança para acidente com material biológico durante estágio curricular de enfermagem

Pós-graduação em Educação - FFC

Interstitial oxygen's influence on the corrosion behavior of Ti-9Mo alloys

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

DNA for nano-bio scale computation of chemical formalisms using Higher Order Logic (HOL) and analysis using an interdisciplinary approach

Bio-molecular computing, 'computations performed by bio-molecules', is already challenging traditional approaches to computation both theoretically and technologically. Often placed within the wider context of ´bio-inspired' or 'natural' or even 'unconventional' computing, the study of natural and artificial molecular computations is adding to our understanding of biology, physical sciences and computer science well beyond the framework of existing design and implementation paradigms. In this introduction, We wish to outline the current scope of the field and assemble some basic arguments that, bio-molecular computation is of central importance to computer science, physical sciences and biology using HOL - Higher Order Logic. HOL is used as the computational tool in our R&D work. DNA was analyzed as a chemical computing engine, in our effort to develop novel formalisms to understand the molecular scale bio-chemical computing behavior using HOL. In our view, our focus is one of the pioneering efforts in this promising domain of nano-bio scale chemical information processing dynamics.

Theoretical investigation of geometric configurations and vibrational spectra in citric acid complexes

The performance of advanced electronic ceramics is directly related to the synthesis route employed. Sol-gel methods are widely used for this purpose. However, the physicochemical intermediate steps are still not well understood. Better understanding and control of these processes can improve the final quality of samples. In this work, we studied theoretically the formation of metal complexes between citric acid and lithium or barium metal cations with different citric acid/metal proportions, using Density Functional Theory electronic structure calculations. Infrared and Raman scattering spectra were simulated for the more stable geometric configurations. Using this methodology, we identified some features of complexes formed in the synthesis process. Our results show that the complexes can be distinguished by changes in the bands assigned to C=O, COH-, and COO- group vibrations. An estimate of the most stable complexes is made based on total energy.

Utilization of teflon and aluminum oxide for wheel cleaning in Minimum Quantity Lubrication (MQL) grinding

Researches concerning cooling-lubrication optimization in grinding have been conducted to contribute to a more sustainable process. An alternative to flood coolant is minimum quantity lubrication (MQL), which spray oil droplets in a compressed air jet. However, problems related to wheel cleaning were reported, due to wheel loading by a mixture of chips and oil, resulting in worsening of surface quality. This work aims to evaluate the viability of Teflon and aluminum oxide for wheel cleaning, compared to MQL without cleaning and MQL with cleaning by compressed air, through the following output variables: surface roughness, roundness, wheel wear, grinding power and acoustic emission. Vickers microhardness measurements and optical microscopy were also carried out. The results showed that both materials were efficient in cleaning the wheel, compared to MQL without cleaning, but not as satisfactory as compressed air. Much work is to be done in order to select the right material for wheel cleaning.

Experimental RTM manufacturing analysis of carbon/epoxy composites for aerospace application

The success of manufacturing composite parts by liquid composite molding processes with RTM depends on tool designs, efficient heat system, a controlled injection pressure, a stabilized vacuum system, besides of a suitable study of the preform lay-up and the resin system choice. This paper reports how to assemble a RTM system in a laboratory scale by specifying heat, injection and vacuum system. The design and mold material were outlined by pointing out its advantages and disadvantages. Four different carbon fiber fabrics were used for testing the RTM system. The injection pressure was analyzed regarding fiber volume content, preform compression and permeability, showing how these factors can affect the process parameters. The glass transition temperature (Tg) around 203 ºC matched with the aimed temperature of the mold which ensured good distribution of the heat throughout the upper and lower mold length. The void volume fraction in a range of 2% confirmed the appropriate RTM system and parameters choice.

Microwave-assisted hydrothermal synthesis of magnetite nanoparticles with potential use as anode in lithium ion batteries

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of different methods of cooling-lubrication in cylindrical grinding of advanced ceramic dip

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Feasibility of RF Sputtering and PIIID for production of thin films from red mud

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of the length of alkyl side chains in the electronic structure of conjugated polymers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação dos efeitos renais do extrato aquoso de Agaricus blazei Murrill em ratos Wistar in vivo

O Agaricus balzei Murrill (ABM), comumente conhecido como cogumelo-do-sol, tornou-se popular, devido sua utilização no tratamento de diversas doenças, uma vez que a populaçao em geral lhe atribui diversos efeitos benéficos. Sendo assim, o cogumelo em questão é bastante estudado pelos pesquisadores, na tentativa de validar esses possíveis efeitos medicinais. O presente trabalho pretendeu avaliar os efeitos renais e adicionalmente os parâmetros cardiovasculares, analisando os efeitos do extrato aquoso de ABM em ratos Wistar in vivo. Estes estudos foram realizados em gaiolas metabólicas e os animais divididos em dois grupos: controle (n=8), onde os ratos recebiam uma picada para simular a injeção e experimental (n=10),onde os ratos recebiam 1mL de extrato aquoso à 2% por via intraperitoneal, ao longo do período tratado. Foram avaliados: o fluxo urinário de 24h, carga excretada de sódio (Qe Na+) e carga excretada de potássio (Qe K+) durante o período basal (30dias) e o período tratado (60 dias). Já os parâmetros cardiovasculares foram mensurados (com o sistema BIOPAC), ao fim do período de 60dias de tratamento. Por meio destas análises foi possível registrar uma queda aguda de pressão arterial nos ratos do grupo experimental, durante 15min, nesses ratos. Também foram observadas as respostas barorreflexas e a resposta bradicárdia foi menos acentuadas no grupo experimetal após a administração de fenilefrina (5μg/kg) em comparação ao grupo controle (p<0,05). Os resultados de fluxo urinário de 24h, Qe Na+ e Qe K+ demostraram que o extrato aquoso de ABM foi capaz de promover um aumento significativo (p<0,05) de 36%, 20% e 22%, respectivamente. Os resultados aqui apresentados, indicam que esse extrato tem princípios ativos natriuréticos e, além disso, o extrato apresentou uma redução acentuada após 15min da injeção... (Resumo completo, clicar acesso eletrônico abaixo)