Attenuation of upstream-generated low frequency noise by gas turbines

The acoustic transfer functions of low frequency (below 3500 Hz) noise through aircraft turbines were investigated. Model test results were compared with theoretical predictions in order to assess the validity of the theory. Component tests were conducted on both high pressure and low pressure model turbines. The influence of inlet temperature and turbine speed attenuation was evaluated, while the effects of turbine pressure ratio, blade-row choking, and additional downstream stages were determined. Preliminary identification of pertinent aeroacoustic correlating parameters was made

Network classifiers based on social learning

This work proposes a new way of combining independently trained classifiers over space and time. Combination over space means that the outputs of spatially distributed classifiers are aggregated. Combination over time means that the classifiers respond to streaming data during testing and continue to improve their performance even during this phase. By doing so, the proposed architecture is able to improve prediction performance over time with unlabeled data. Inspired by social learning algorithms, which require prior knowledge of the observations distribution, we propose a Social Machine Learning (SML) paradigm that is able to exploit the imperfect models generated during the learning phase. We show that this strategy results in consistent learning with high probability, and it yields a robust structure against poorly trained classifiers. Simulations with an ensemble of feedforward neural networks are provided to illustrate the theoretical results

Expression of Democracy: Local Elections in Petorca, Chile

The municipal elections of Chile were held on April 2,1967. On April 3, in Santiago, spokesmen from the national committees of the five major parties --the Christian Democrats, the Radicals, the Communists, the Nationalists, and the Socialists--all proclaimed that the results showed that their political aggregation had been victorious on the previous day. The debate concerning who had won the election raged for several weeks in the press, in Congress and in spirited social conversation. The Christian Democrats argued that although their percentage of the national vote dropped from forty-two per cent to thirty-five per cent, they had increased their strength in the municipal councils by over two hundred representatives to six hundred and forty-nine councilmen, a new record for any single political party in all of Chile\u27s history. The leftist coalition of FRAP (Communist-Socialist) boasted that they reflected the coming wave in Chilean politics by gathering nearly twenty-eight per cent of the total vote, an increase of six per cent from 1965. The Radicals announced with relief that they had retained second place in party percentages (sixteen per cent), and that their vote represented a vehement renunciation of the whole Christian Democratic movement. The National Party, perhaps the most surprised by its strong showing (fourteen per cent), predicted that the Right was not a dead letter in Chile, and that a new awakening was imminent

Utilização de um delineamento composto central rotacional para avaliação microbiológica de polpas de açaí pasteurizadas.

O açaí é um fruto nativo da região Amazônica brasileira, cuja polpa tem sido amplamente comercializada no mundo. Sendo altamente perecível pelas suas características intrínsecas e de pré-processamento, o processo de pasteurização torna-se essencial. Dessa forma, o objetivo deste trabalho foi investigar como o binômio tempo e temperatura influencia nas características microbiológicas da polpa, e, através de um delineamento experimental determinar as melhores condições de processo visando à segurança do produto. Utilizou-se polpa de açaí proveniente de Belém, Pará e um sistema de pasteurização tubular. O planejamento adotado foi do tipo composto central rotacional 22 e como respostas foram realizadas análises de bactérias mesófilas e bolores e leveduras. A avaliação estatística do planejamento mostrou que, para bactérias, as variáveis temperatura e tempo, linear e quadrática, foram significativas (p?0,05). Porém, quando submetidos à análise de variância, os resultados foram considerados insatisfatórios para geração de um modelo preditivo (R2 = 0,39; Fcalculado/Ftabelado0,10). Entretanto, os gráficos de tendência indicaram que a variável tempo exerceu maior influência no processo. Para bolores e leveduras, observou-se destruição em sua totalidade, com contagens finais de <10 UFC/g (est.). De acordo com o conjunto de resultados obtidos, sugere-se a adoção de um tempo mínimo de 35s e temperatura acima de 75ºC para a pasteurização da polpa de açaí