janeiro usando redes: Topics by WorldWideScience.org

... The high resolution imagery , collected over Rio de Janeiro, Brazil, included a mixture of large commercial buildings and private houses, as well as the airport and some community parks. 10/08/11 Read more Top EU R&D companies expect a 5% ...

7

Monitoring drinking water networks by data telemanagement; Telegestion de datos para control de redes de agua potable

Energy Technology Data Exchange (ETDEWEB)

The WIT telemanagement system simply, reliably and efficient by makes available to us in real time processed, ordered and managed data. Such information has been used to optimise the performance of the drinking water distribution networks on a number of housing estates. This has led to major saving in consumption and on equipment maintenance, thereby improving customer service and obtaining a more rational use of piped water. (Author)

1997-04-01

8

Velocity control in three-phase induction motors using PIC; Controle de velocidade de motor de inducao trifasico usando PIC

Energy Technology Data Exchange (ETDEWEB)

This paper presents a technique for speed control three-phase induction motor using the pulse width modulation (PWM), in open loop while maintaining the tension for constant frequency. The technique is adapted from a thesis entitled 'Control of the three-phase induction motor, using discrete PWM generation, optimized and synchronized', where studies are presented aimed at their application in home appliances, to eliminate mechanical parts, replaced by low cost electronic control, thus having a significant reduction in power consumption. Initially the experiment was done with the Intel 80C31 micro controller. In this paper, the PWM modulation is implemented using a PIC micro controller, and the speed control kept a low profile, based on tables, synchronized with transitions and reduced generation of harmonics in the network. Confirmations were made using the same process of building tables, but takes advantage of the program of a RISC device.

2009-07-01

9

Treatment of produced water using hydrocyclones; Tratamento de agua produzida usando hidrociclone

Energy Technology Data Exchange (ETDEWEB)

Beyond a great number of applications in mineral process, the hydrocyclone separation has been used recently in an increasing number of fields, such as: environmental engineering, petrochemical engineering, food engineering, electrochemical engineering, pulp bioengineering, processes and paper industries, among others. Nowadays, the produced water is treated and then reinjected in the surface and also in return to the formation. In the offshore platforms, the produced water can be directly discarded in the ocean, since the dispersed phase concentration (oil) is according to Brazilian regulating agency limits. The basic principle used in hydrocyclone separation is the centrifugal sedimentation machine: the suspended particles are submitted to centrifugal acceleration, which separates them from the fluid. The basic geometry of a hydrocyclone consists of four parts: a cylindrical section for feeding, a conical section for swirling, an overflow and an under flow. The project depends on the ...

2008-07-01

10

The biofuels excellence network; Rede de excelencia em biocombustiveis

Energy Technology Data Exchange (ETDEWEB)

The organization of the Biofuels Excellence Network, inside PROMINP - the Program of Mobilization of the National Industry of Oil and Natural Gas, has the objective of improving the actions of technical innovation and management in the chain of Oil, Gas Natural and Biofuels, through the optimized use of physical, financial, technological resources, of information and staff, with maximum qualification in areas of the human knowledge, whose purpose is to make decisions on specific problems of improvement of processes and/or products, besides promoting actions for the development and reinforcement of the markets of ethanol and biodiesel. The organization of the Biofuels Excellence Network became necessary, in order to enable Brazil to reach vanguard standards in biofuels (ethanol and biodiesel) in a sustainable, competitive and environmentally responsible way. Among the main reasons for the creation of the Biofuels Excellence Network are: to speed up the acquisition of knowledge and ...

2008-07-01

11

Radiolytic stabilization of poly(methyl methacrylate) using commercial additives; Estabilizacao radiolitica do poli(metacrilato de metila) usando aditivos comerciais

Energy Technology Data Exchange (ETDEWEB)

Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub g}) of PMMA (no ...

2000-04-01

12

Adaptive power system stabilizer with previous programming of parameters and artificial neural network; Estabilizador de sistemas de potencia adaptativo com pre-programacao de parametros e rede neural artificial

Energy Technology Data Exchange (ETDEWEB)

This work presents a digital adaptive Power System Stabilizer (PSS) which operates in a gain scheduling scheme. It`s parameters are designed for a lot of different operating regions in a P x Q plane (active and reactive powers), and saved in a microcomputer real time control. During working, the PSS identifies the present region of operation, and synthesizes its damping signal in accordance with the parameters for that region. As an extension of the method, a neural PSS, which uses the set of parameters of each region as a standard set to train a neural network to form this PSS, is also proposed. The tests presented show good performance for both PSS, when compared to a conventional (non adaptive) one. (author) 10 refs., 5 figs., 1 tab.; e-mail: jalb at guama.cpgee.ufpa.br

1997-12-31

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A method for the optimal design of networks of drinking water distribution; Un metodo para el diseno optimo de redes de distribucion de agua potable

Energy Technology Data Exchange (ETDEWEB)

A method to select, among several commercial diameter options, the most economic combination of pipeline networks is presented. These networks comply with the discharge conditions in the pipes and pressure in the knots. It is applied a static method for the hydraulics analysis of the Engineering Institute of the Universidad Nacional Autonoma de Mexico (UNAM) and an optimization technique to reduce the number of calculations. [Spanish] Se presenta un metodo para seleccionar, de entre varias opciones de diametros comerciales, la combinacion que forma la red de tuberias mas economica que satisface las condiciones de gasto en los tubos y de presion en los nudos de la misma. Para el analisis hidraulico se emplea un metodo estatico del Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM) y se aplica una tecnica de optimacion para reducir el numero de calculos y alcanzar la solucion.

1998-12-01

14

Against a wintry sky, a few swallows

Energy Technology Data Exchange (ETDEWEB)

The disappointing progress in toxic emission reductions and sustainable economic development the world over, has been reviewed five years after the Rio de Janeiro Environmental Summit. The author`s conclusion is that there has been no progress at all, and that politicians, once again, seized on the language of sustainable development while emptying it of meaning. Sustainable development requires market regulation and the subordination of economic objectives to social need. Instead, there has been a rise of neo-liberalism. This is a type of historical counter-current that has been developing over the past two decades. It advocates unlimited deregulation, the weakening of governments, and the primacy of economic interests focused on the search for profits. It is the view of this author that so long as the conflict between sustainable development and extreme liberalism is not recognized and discussed, there is little chance that we can advance appreciably. Moreover, ...

1997-09-01

15

A smart location system

Energy Technology Data Exchange (ETDEWEB)

Details of a novel intelligent pipeline anomaly location system were presented. The system was based on the emission and reception of extra low frequencies(ELF) disposed close to a pipeline that were then logged in the memory of an in-line inspection (ILI) tool to provide a more precise reference than time-based above-ground marker systems for the location of pipeline anomalies. The system consisted of 2 pairs of transmitter (TX) and receiving (RX) circuits working at low and varied frequencies. An additional module was installed in the front section of an ILI tool, which contained a frequency transmitter whose signals are transmitted through cabling to an external transmitter and retransmitted simultaneously to a receiver installed in the rear section of an additional module of the tool in order to guarantee that the signal recorded by the tool corresponded to the smart location system. The system was used to detect anomalies in a subsea pipeline near Rio de ...

2004-07-01

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