Sobre um método assemelhado ao de Francis para a determinação de autovalores de matrizes

Pós-graduação em Matemática - IBILCE

As vozes e as coisas: a poesia em prosa de Murilo Mendes e Francis Ponge

O livro compara duas importantes obras de poesia em prosa das literaturas brasileira e francesa, o Poliedro, de Murilo Mendes e o Le parti pris des choses, de Francis Ponge, publicadas respectivamente em 1972 e 1942. Para a autora, a aproximação se justifica pelo foco dado nas duas obras aos objetos mais cotidianos possíveis e, ainda, pelo posicionamento diferente dos sujeitos líricos muriliano (menos objetivo) e pongiano (mais objetivo) diante das coisas simples do mundo. O brasileiro e o francês também partilhariam de uma determinada comunidade de interesses históricos, literários e sociais, ainda que as obras em questão estejam separadas por um intervalo de publicação de trinta anos e, neste intervalo, tenham ocorrido acontecimentos políticos, sociais e artísticos que reverberaram inevitavelmente na literatura desses poetas. Para a autora, a própria escolha da forma do poema em prosa pelos dois autores também os uniria, na medida em que este formato contribuiu enormemente para a construção singular dos objetos, bem como das duas vozes líricas tão particulares

Thermodynamic analysis and comparison of downdraft gasifiers integrated with gas turbine, spark and compression ignition engines for distributed power generation

The objective of the present article is to assess and compare the performance of electricity generation systems integrated with downdraft biomass gasifiers for distributed power generation. A model for estimating the electric power generation of internal combustion engines and gas turbines powered by syngas was developed. First, the model determines the syngas composition and the lower heating value; and second, these data are used to evaluate power generation in Otto, Diesel, and Brayton cycles. Four synthesis gas compositions were tested for gasification with: air; pure oxygen; 60% oxygen with 40% steam; and 60% air with 40% steam. The results show a maximum power ratio of 0.567 kWh/Nm(3) for the gas turbine system, 0.647 kWh/Nm(3) for the compression ignition engine, and 0.775 kWh/Nm(3) for the spark-ignition engine while running on synthesis gas which was produced using pure oxygen as gasification agent. When these three systems run on synthesis gas produced using atmospheric air as gasification agent, the maximum power ratios were 0.274 kWh/Nm(3) for the gas turbine system, 0.302 kWh/Nm(3) for CIE, and 0.282 kWh/Nm(3) for SIE. The relationship between power output and synthesis gas flow variations is presented as is the dependence of efficiency on compression ratios. Since the maximum attainable power ratio of CIE is higher than that of SIE for gasification with air, more research should be performed on utilization of synthesis gas in CIE. (C) 2014 Elsevier Ltd. All rights reserved.

Performance and emissions of a gas turbine engine using ox tallow ethyl-ester blended with kerosene

The performance and emissions behavior of a Rover 1S/60 turboshaft engine when operated with several blends of aviation kerosene and ox tallow ethyl-ester are shown in this article. The tests were performed with a compressor shaft coupled to an hydraulic dynamometer where data of power and mass fuel flow were collected to determine the brake specific fuel consumption. A flue gas analyzer was positioned at the exhaust duct to collect oxygen, carbon dioxide, carbon monoxide and nitrous oxides. An increase in the specific fuel consumption was observed due to the lesser lower heating value of the most oxygenated blends. However, reductions of CO, CO2 and NO (x) have been observed and no-significant ill effects have occurred in the turbine operation.

Murilo Mendes, Francis Ponge e o poema em prosa

The present paper aims to discuss the configuration of the prose poem both in the works of Murilo Mendes' Poliedro (1972) and Francis Ponge's Le parti pris des choses (1942). From the beginning, the similarity between both works is explained by the impulse of focusing on daily objects and also the diverse positioning of the lyrical subjects in Murilo Mendes (less objective) and Francis Ponge (more objective) when they establish a relation with the simple things they wish to marvel. In accordance, the form of the prose poem helps to build this specific and singular view of the objects. Using this background to dialogue with the critical scholarly resources on both writers, we briefly analyse some poems and set out to reflect on the prose poem, which holds the works of the Brazilian and the French poets open to comparison.

Tradução anotada, autor-tradutor invisível: Richard Francis Burton na Brasiliana

The aim of this paper is to analyze the translation of the work by the translator-traveller Richard Francis Burton, Explorations of the Highlands of the Brazil, with a full account of the gold and diamond mines, made by Américo Jacobina Lacombe, trying to relate the work of the latter to the editorial goals of the Brasiliana Collection. As a subseries of the Biblioteca Pedagógica Brasileira [Brazilian Pedagogical Library] published by Companhia Editora Nacional, Brasiliana was conceived in agreement with the 1930s and 1940s policies to expand lay education and make it possible for Brazilians to get to better know the greatness of their country. The paper will focus on the numerous translator’s notes, since many of them reveal Lacombe’s didactic purpose of informing readers about Brazilian history and geography. The analysis also examines the effacement of Burton’s translations from Portuguese into English in his book.

Thermodynamic, Economic and Emissions Analysis of a Micro Gas Turbine Cogeneration System operating on Biofuels

Pós-graduação em Engenharia Mecânica - FEG

A swirler stabilized combustion chamber for a micro-gas turbine fuelled with natural gas

Micro-gas turbines are a good alternative for on-site power generation, since their operation is very reliable. The possibility of operating with various fuels increases versatility and, as a result, the usage of these devices. Focusing on a performance improvement of a tri-fuel low-cost micro-gas turbine, this work presents investigations of the inner flow of its combustion chamber. The aim of this analysis was the characterization of the flame structure by the temperature field of the chamber inner flow. The chamber was fuelled with natural gas. In the current chamber, a swirler and a reversed flow configuration were utilized to provide flame stabilization. The inner flow investigations were done with numerical analysis, which were compared to experimental data. The analysis of the inner flow was done with numerical simulations, which used the RSM turbulence model. A β-PDF equilibrium model was adopted to account for the turbulent combustion process. Different models of heat transfer were compared. Thermal radiation and specially heat conduction in the liner walls played significant roles on results.

Metodologie e procedure per la verifica del rendimento delle turbine eoliche in condizioni operative ed orografia complessa

La tesi verte sulle procedure di verifica delle prestazioni di potenza degli aerogeneratori. Si è realizzato un test di verifica su una centrale eolica in esercizio, sito nella provincia di Salerno, utilizzando diverse metodologie di verifica, delineate dai più importanti centri di ricerca internazionali, al fine di valutare l'affidabilità di ognuna di esse.

Progetto e modellazione CAD di micro turbine eoliche

Progetto di due turbine eoliche di piccola potenza per alimentare utenze remote. Sia la turbina ad asse verticale che quella ad asse orizzontale sono state dimensionate andando ad ottimizzare il funzionamento per un vento di 7.5 m/s ed un carico dato da un alternatore da 500W. Entrambe le turbine sono poi state modellate al CAD e sono stati realizzati i disegni costruttivi di alcuni elementi delle stesse.