uma liga amorfa: Topics by WorldWideScience.org

A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

2007-08-14

Sulphate addition of Fe-Nb, Co-Nb and Ni-Nb alloys in mixtures H{sub 2}-H{sub 2} S at 800 deg C; Sulfetacao de ligas Fe-Nb, Co-Nb e Ni-Nb em misturas H{sub 2}-H{sub 2} S a 800 C

Energy Technology Data Exchange (ETDEWEB)

Short communication

1993-12-31

P-LIGA: 3D-integration of microstructures with curved surfaces by deep ion irradiation

International Nuclear Information System (INIS)

Using the advantage that the projected range of ions in matter is sharply limited, a new technique for the production of three-dimensional microstructures has been developed. Based on the P-LIGA technique (Proton-Lithographie, Galvanoformung, Abformung) this process allows the generation of structures with surfaces of almost any shape having a root mean square roughness of about #lambda#/50 for visible light wavelengths. An ion beam with diameters between 2 and 50 #mu#m is directly writing the structures and the shape is varied by geometrical manipulation of the sample in three axes during the exposure. Practically, structures have been written using protons with an energy of 1.8 MeV in a provisional experimental setup with beam diameters of 10 and 50 #mu#m, respectively. After irradiation, the parts exposed were dissolved in a liquid developer without affecting the nonirradiated parts. The shape and the rms roughness of the resulting structures were estimated by ...

1998-04-01

Electric induction on a trolley bus contact line, running parallel to a 138 KV overhead transmission line; Inducao em linha de contato de trolebus paralela a uma linha de transmissao de 138 kV

Energy Technology Data Exchange (ETDEWEB)

Results obtained on induced current and voltage caused by a high voltage transmission lines running parallel at a trolley bus contact lines, are presented. A computer program in Basic language, was developed to calculate the electric induction, problems of safety, a theoretical development and mathematical model of the electric factors between two lines (inductor and induced) are also discussed. 11 figs., 1 tab., 8 refs.

1991-12-31

Development of a synchronous key to controlled energization of three-phase transformers; Desenvolvimento de uma chave sincrona para energizacao controlada de transformadores trifasicos

Energy Technology Data Exchange (ETDEWEB)

This work describes the development of a synchronous key based on micro controller to the switching of three-phase power transformers, which makes possible the achievement of tests to register the inrush current, and the previous establishment of the instantaneous values of the voltage firstly applied to different phases of the energy process. This key is a value tool to the development electric power system projects and to the teaching and researching activities at the laboratory related to transitory phenomena and electric system protection.

2009-07-01

Determination of the semi-empiric relationship among the physical density, the concentration and rate between hydrogen and manganese atoms, and a manganese sulfate solution; Determinacao da relacao semi-empirica entre a densidade fisica, concentracao e razao entre atomos de hidrogenio e manganes em uma solucao de sulfato de manganes

Energy Technology Data Exchange (ETDEWEB)

The bath of a manganese sulfate (BMS) is a system for absolute standardization of the neutron sources. This work establishes a functional relationship based on semi-empirical methods for the theoretical prediction of physical density values, concentration and rate between the hydrogen and manganese atoms presents in the solution of the BMS

2009-07-01

A contribution to the study of the thermal behavior and of the electric performance of squirrel-cage induction motors; Uma contribuicao ao estudo do comportamento termico e do desempenho eletrico de motores de inducao com rotor em gaiola

Energy Technology Data Exchange (ETDEWEB)

A thermal-electric mathematical model for a squirrel cage induction motors which permits to specify the best motor for specific drive, under thermal and electric aspects based, only on manufacturer technical bulletins and technical information is presented. Changes of rotor parameters due Skin Effect and changes of winding resistances (both stator and rotor) with the temperature are considered. The accuracy of this model is appraised using experimental results. The thermal behavior and electric performance for some motors are obtained for continuos and intermittent duties with sinusoidal and non-sinusoidal voltages. (author)

1992-03-01

Re-potentiation of hydro-generators: a proposal of analysis and implementation methodology; Repotenciacao de hidrogeradores: uma proposta de metodologia de analise e implantacao

Energy Technology Data Exchange (ETDEWEB)

The hydro-generators suffer during its operative useful life a combination of stresses of nature thermal, electric, mechanics and environmental. With the time, they are going losing the capacity to support those stresses and the power plants suffer, more and more frequently, undesirable stops for repair services and maintenance. In function of the high costs incurred with these stopped, the operation of the power plant can be economically impracticable. That unavailability of the generation for the electric system, it results in reduction of the reliability, burdening the politics of load ruling. The re-potentiation is a proposal that seeks to extend the useful life of hydro-generators, at the same time that it try to rescue the reliability and the readiness of the plant, with larger power. The power increase is usually made possible, or for the surplus of the hydro resources in excess, or for the reduction of the losses of all the components of the energy flow. That work proposes a ...

1996-07-01

Atmospheric emissions as a tool in evaluation of sustainability research in oil industry; Emissao atmosferica como uma ferramenta na avaliacao do desenvolvimento sustentavel na industria do petroleo

Energy Technology Data Exchange (ETDEWEB)

This work is directly to analysis of atmosphere surrounding Ipiranga Refinery; witch is located in the city of Rio Grande, in estate of Rio Grande do Sul. The refinery is surrounded by neighborhood, witch are impacted by atmospheric emissions of refinery. The objective of this work is correlating the refinery to the inhabitants that lives near the refinery, using an environmental sustainability index. This work will be achieve by analysis of Polycyclic Aromatic Hydrocarbons (PAH) bounded in particulate matter with diameter of 100 {mu}m (PTS), the acquisition of health data on the city hospitals and correlation of this data with PAH concentrations in Particulate Matter. The Samples were obtain by FEPAM, witch have three samples sites in the center of city. The samples was obtained by a High Volume Sampler equipped with quartz fiber filters. The meteorological data important to this work, like wind direction and speed, will be obtain in Meteorological Station on FURG. The results expect ...

2008-07-01

Novel silicon fabrication process for high-aspect-ratio micromachined parts

Energy Technology Data Exchange (ETDEWEB)

Bulk micromachining generally refers to processes involving wet chemical etching of structures formed out of the silicon substrate and so is limited to fairly large, crude structures. Surface micromachining allows intricate patterning of thin films of polysilicon and other materials to form essentially two-dimensional layered parts (since the thickness of the parts is limited by the thickness of the deposited films). There is a third type of micromachining in which the part is formed by filling a mold which was defined by photolithographic means. Historically micromachining molds have been formed in some sort of photopolymer, be it with x-ray lithography (``LIGA``) or more conventional UV lithography, with the aim of producing piece parts. Recently, however, several groups including ours at Sandia have independently come up with the idea of forming the mold for mechanical parts by etching into the silicon substrate itself. In Sandia`s mold process, the mold is ...

1995-08-01

Mechanodynamical analysis of nickel-titanium alloys for orthodontics application; Analise mecanodinamica de ligas de niquel-titanio para aplicacao ortodontica

Energy Technology Data Exchange (ETDEWEB)

Nickel-titanium alloys may coexist in more than one crystalline structure. There is a high temperature phase, austenite, and a low temperature phase, martensite. The metallurgical basis for the superelasticity and the shape memory effect relies in the ability of these alloys to transform easily from one phase to another. There are three essential factors for the orthodontist to understand nickel-titanium alloys behaviour: stress; deflection; and temperature. These three factors are related to each other by the stress-deflection, stress-temperature and deflection-temperature diagrams. This work was undertaken with the objective to analyse commercial nickel-titanium alloys for orthodontics application, using the dynamical mechanical analyser - DMA. Four NiTi 0,017 X 0,025'' archwires were studied. The archwires were Copper NiTi 35 deg C (Ormco), Neo Sentalloy F200 (GAC), Nitinol Superelastic (Unitek) and NiTi (GAC). The different mechanodynamical properties such as ...

2002-07-01

Uranium hexafluoride production plant decommissioning; Descomissionamento de uma usina de producao de hexafluoreto de uranio

Energy Technology Data Exchange (ETDEWEB)

The Institute of Energetic and Nuclear Research - IPEN is a research and development institution, located in a densely populated area, in the city of Sao Paulo. The nuclear fuel cycle was developed from the Yellow Cake to the enrichment and reconversion at IPEN. After this phase, all the technology was transferred to private enterprises and to the Brazilian Navy (CTM/SP). Some plants of the fuel cycle were at semi-industrial level, with a production over 20 kg/h. As a research institute, IPEN accomplished its function of the fuel cycle, developing and transferring technology. With the necessity of space for the implementation of new projects, the uranium hexafluoride (UF{sub 6}) production plant was chosen, since it had been idle for many years and presented potential leaking risks, which could cause environmental aggression and serious accidents. This plant decommission required accurate planning, as this work had not been carried out in Brazil before, for this type of facility, and ...

2008-07-01

Occupational exposure prevention program to oil and gas industry; Antecipacao, reconhecimento, avaliacao e controle dos riscos ambientais em uma planta de petroleo e gas

Energy Technology Data Exchange (ETDEWEB)

PETROBRAS/TRANSPETRO Pipelines and Terminals have 500 regular employees and 5.064 out sourced workers in its Southeast Division. The out sourced employees work under 125 contracts involving a wide range of activities such as maintenance, pipeline operation, pipeline launching, engineering, administrative and auxiliary services. Among these workers, 1.200 peoples are subjected to occupational exposure, which may be present in the industrial process or in the products transported in our pipelines, e.g. industrial noise, sulfidric gas, toluene, xylene and benzene (recognized as a carcinogen according to ACGIH and Brazilian Ministry of Labour). Our PPRA (acronym in Portuguese for Occupational Exposure Prevention Program) involves the workforce and fosters health by anticipation, recognition, evaluation and control of the situations that may result in injuries. Further actions include the procurement of equipment for detection of these agents not only in the air but also diluted in liquids ...

2005-07-01

1 2

Markov random fields simulation: an introduction to the stochastic modelling of petroleum reservoirs; Simulacao de campos aleatorios markovianos: uma introducao voltada a modelagem estocastica de reservatorios de petroleo

Energy Technology Data Exchange (ETDEWEB)

Stochastic simulation has been employed in petroleum reservoir characterization as a modeling tool able to reconcile information from several different sources. It has the ability to preserve the variability of the modeled phenomena and permits transference of geological knowledge to numerical models of flux, whose predictions on reservoir constitute the main basis for reservoir management decisions. Several stochastic models have been used and/or suggested, depending on the nature of the phenomena to be described. Markov Random Fields (MRFs) appear as an alternative for the modeling of discrete variables, mainly reservoirs with mosaic architecture of facies. In this dissertation, the reader is introduced to the stochastic modeling by MRFs in a generic sense. The main aspects of the technique are reviewed. MRF Conceptual Background is described: its characterization through the Markovian property and the equivalence to Gibbs distributions. The framework for generic modeling of MRFs is ...

1998-02-01

Characterisation of thin films on rough steel substrates by FTIR microscopy and imaging

International Nuclear Information System (INIS)

Complete text of publication follows. According to the new European regulations (Restrictions of Hazardous Substance Directive), there is an emerging demand for environmental friendly metal treatments instead on formerly used chromate conversion coating technique. The aim of the present investigations was to characterise and compare silicon containing protective thin layers on roughened galvanized steel surfaces (with average roughness of 0.7 microns), using FTIR microscopy and imaging techniques. The silicon containing coatings were produced either by Chemical Vapour Deposition (CVD) or by wet chemical treatment using liquid silane. FTIR techniques offer new possibilities in the characterisations and chemical mapping of differently coated thin films, besides SEM+EDS, AFM, nanoindentation, XPS measurements (P. Nemeth et al., Materials Science Forum, 589 (2008) 433-438). All measurements were carried out by a Varian FTS-7000 spectrometer with a 'Stingray' microscope configuration ...

1 2

Sample records for uma liga amorfa from WorldWideScience.org