21 resultados para Naval gunnery.


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After years of stagnation, the naval construction industry in Brazil has been experiencing a period of recovery caused by investments in the oil and gas sector and the implementation of governmental programs that aimed to regenerate it. However, efforts in learning and innovations are needed in order to reinsert the country in this activity and achieve international levels of competitiveness. Based on literature about learning processes and continuous improvement practices and their impact in the innovative and productive processes, this paper aims to identify the main tendencies, mechanisms and procedures to improve the construction and management processes in the Brazilian naval construction industry. The methodology used for the data analysis classifies obtained information from magazines and annals of congresses of the sector, according to the established analysis categories (phenomena). Such categories study information related to the productive and technological processes of the industry, the main internal and external relations of the industrial park, the management of resources and processes, policies, investments, etc. The data was collected in the period 2004-2010, and more than 500 registers that show a dominance of the investment phenomenon, especially in the increase of productive capacity, were catalogued. In addition to this, there is evidence of modernization in the manufacturing plan and the equipment, diverse forms of cooperation, implementation of human resources management practices and engineering or processes and products. Hence, a process of catching up governs and is guided by modernization and increase training in this industry.

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A concepção filosófica do mundo se inicia com os gregos sintetizados por Platão e Aristóteles. Para o primeiro o mundo físico é aparente e para se chegar à verdade é preciso se lembrar das idéias originais que determinam seu significado. Para o segundo as coisas físicas são dirigidas pelas idéias e para entendê-las é preciso a lógica. Durante o helenismo a escola de Alexandria elabora o neoplatonismo, a base da Patrística. Após a queda de Roma, os filósofos bizantinos guardam a herança clássica. A Igreja constrói uma visão neoplatônica da cristandade, a Escolástica. No oriente os persas também sofreram a influência grega. Entre os árabes do Oriente o pensamento neoplatônico orienta filósofos e religiosos de forma que para eles a razão e a fé não se separam. Aí a ciências se desenvolvem na física, na alquimia, na botânica, na medicina, na matemática e na lógica, até serem subjugadas pela doutrina conservadora dos otomanos. Na Espanha mulçumana sem as restrições da teologia, a filosofia de Aristóteles é mais bem compreendida do que no resto do Islã. Também aí todas as ciências se desenvolvem rápido. Mas a Espanha sucumbe aos cristãos. Os árabes e judeus apresentam Aristóteles à Europa Ocidental que elabora um Aristóteles cristão. A matemática, a física experimental, a alquimia e a medicina dos árabes influenciam intensamente o Ocidente. Os artesãos constroem instrumentos cada vez mais precisos, os navegadores constroem navios e mapas mais eficientes e minuciosos, os armeiros calculam melhor a forma de lançamento e pontaria de suas armas e os agrimensores melhor elaboram a medida de sua área de mapeamento. Os artistas principalmente italianos, a partir dos clássicos gregos e árabes, criam a perspectiva no desenho, possibilitando a matematização do espaço. Os portugueses, junto com cientistas árabes, judeus e italianos, concluem um projeto de expansão naval e ampliam os horizontes do mundo. Os pensadores italianos, como uma reação à Escolástica, constroem um pensamento humanista influenciado pelo pensamento grego clássico original e pelos últimos filósofos bizantinos. Por todas essas mudanças se inicia a construção de um novo universo e de um novo método, que viria décadas mais tarde.

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The scientific and technological development in the area of new materials contributed to several applications of niobium and its alloys in nuclear power plants as well as in aerospace, aeronautics, automobile and naval industries. This paper presents the interstitial diffusion coefficients of nitrogen in solid solution in the Nb-1.0wt%Zr alloy using internal friction measurements obtained by mechanical spectroscopy, which uses a torsion pendulum operating at an oscillation frequency between 1.0 Hz and 10.0 Hz. The temperature range varies from 300K to 700K, at a heating rate of 1 K/min and vacuum better than 2 x 10(-6) Torr. The results showed an increase of the interstitial diffusion coefficient of nitrogen that was correlated with configurational considerations for the octahedral interstitials.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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The transfer formulas are used to compute hourly values of sensible and latent heat exchanges for the period July 29 to July 31, 1974. Also, values of eddy shearing stress at the sea surface, Bowen's ratio and dissipation of kinetic energy are computed. The data used cover part of the GATE period for station 20 occupied by the Brazilian Naval Ship R/V Sirius in the Equatorial Atlantic (0730 N 4000 W). The variations in the computed values are studied in relation to rainfall and the synoptic situation. © 1980 D. Reidel Publishing Co.

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This paper describes the design and development of a high input power-factor (HPF) AC to AC converter for naval applications using Permanent Magnet Generator (PMG). The proposed converter comprises an isolated three-phase uncontrolled multipulse rectification stage directly connected to a single-phase inverter stage, without the use of DC to DC intermediary stage, resulting in more simplicity for the overall circuitry, assuring robustness, reliability and reduced costs. Furthermore, the multipulse rectifier stage is capable to provide high power factor and input currents with low total harmonic distortion (THD). The output voltage of the PMG varies from 260V rms (220 Hz) to 380V rms (360 Hz), depending on load conditions. The output single-phase inverter stage was designed to operate with wide range of DC bus voltage, maintaining 120V rms, 60 Hz output. Measured total harmonic distortion for the AC output voltage represents less than 2%, at 3.6kW nominal linear load. © 2010 IEEE.

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This paper proposes and describes a high power factor AC-AC converter for naval applications using Permanent Magnet Generator (PMG). The three-phase output voltages of the PMG vary from 260 Vrms (220 Hz) to 380 Vrms (360 Hz), depending on load conditions. The proposed converter consists of a Y-/ΔY power transformer, which provides electrical isolation between the PMG and remaining stages, and a twelve-pulse uncontrolled rectifier stage directly connected to a single-phase inverter stage, without the use of an intermediary DC-DC topology. This proposal results in more simplicity for the overall circuitry, assuring robustness, reliability and reduced costs. Furthermore, the multipulse rectifier stage is capable to provide high power factor and low total harmonic distortion for the input currents of the converter. The single-phase inverter stage was designed to operate with wide range of DC bus voltage, maintaining 120 Vrms, 60 Hz output. The control philosophy, implemented in a digital signal processor (DSP) which also contains protection routines, alows series connections between two identical converters, achieving 240 Vrms, 60 Hz total output voltage. Measured total harmonic distortion for the AC output voltage is lower than 2% and the input power factor is 0.93 at 3.6kW nominal load. © 2010 IEEE.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Ciência da Informação - FFC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Relações Internacionais (UNESP - UNICAMP - PUC-SP) - FFC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)