884 resultados para Turning traffic.


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In this study, different methods of cutting fluid application are used in turning of a difficult-to-machine steel (SAE EV-8). Initially, a semisynthetic cutting fluid was applied using a conventional method (i.e. overhead flood cooling), minimum quantity of cutting fluid, and pulverization. A lubricant of vegetable oil (minimum quantity of lubricant) was also applied using the minimum quantity method. Thereafter, a cutting fluid jet under high pressure (3.0 MPa) was singly applied in the following regions: chip-tool interface, top surface of the chip (between workpiece and chip) and tool-workpiece contact. Moreover, two other methods were used: an interflow between conventional application and chip-tool interface jet (combined method) and, finally, three jets simultaneously applied. In order to carry out these tests, it was necessary to set up a high-pressure system using a piston pump for generating a cutting fluid jet, a venturi for fluid application (minimum quantity of cutting fluid and minimum quantity of lubricant) and a nozzle for cutting fluid pulverization. The output variables analyzed included tool life, surface roughness, cutting tool temperature, cutting force, chip form, chip compression rate and machined specimen microstructure. Among the results, it can be observed that the tool life increases and the cutting force decreases with the application of cutting fluid jet, mainly when it is directed to the chip-tool interface. Excluding the methods involving jet fluid, the conventional method seems to be more efficient than other methods of low pressure, such as minimum quantity of volume and pulverization, when considering just the cutting tool wear. © 2013 IMechE.

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Different methods of cutting fluid application are used on turning of a difficult-tomachine steel (SAE EV-8). A semi-synthetic cutting fluid was applied using a conventional method, minimum quantity of cutting fluid (MQCF), and pulverization. By the minimum quantity method was also applied a lubricant of vegetable oil (MQL). Thereafter, a cutting fluid jet under high pressure (3.0 MPa) was singly applied in the following regions: chip-tool interface; top surface of the chip; and tool-workpiece contact. Two other methods were used: an interflow between conventional application and chip-tool interface jet and, finally, three jets simultaneously applied. In order to carry out these tests, it was necessary to set up a high pressure system using a piston pump for generating a cutting fluid jet, a Venturi for fluid application (MQCF and MQL), and a nozzle for cutting fluid pulverization. The output variables analyzed included tool life, surface roughness, cutting tool temperature, cutting force, chip form, chip compression rate and machined specimen microstructure. It can be observed that the tool life increases and the cutting force decreases with the application of cutting fluid jet, mainly when it is directed to the chip-tool interface. Excluding the methods involving jet fluid, the conventional method seems to be more efficient than other methods of low pressure. © (2013) Trans Tech Publications, Switzerland.

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Includes bibliography

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Includes bibliography

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This paper presents simulation results of the DNP3 communication protocol over a TCP/IP network, for Smart Grid applications. The simulation was performed using the NS-2 network simulator. This study aimed to use the simulation to verify the performance of the DNP3 protocol in a heterogeneous LAN. Analyzing the results it was possible to verify that the DNP3 over a heterogeneous traffic network, with communication channel capacity between 60 and 85 percent, it works well with low packet loss and low delay, however, with traffic values upper 85 percent, the DNP3 usage becomes unfeasible because the information lost, re-transmissions and latency are significantly increased. © 2013 IEEE.

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Includes bibliography

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Traffic congestion has become a severe scourge in large cities, in both the industrialized and developing countries. Increasing demand for urban transport and transit has led to longer travel times, and a greater incidence of accidents, environmental problems and deterioration in the quality of life than is considered acceptable for citizens. A multidisciplinary approach is required in order to keep the negative effects of congestion under control and to ensure standards of living remain sustainable. In view of the seriousness of the problem, ECLAC with the support of the German Agency for Technical Cooperation (GTZ) is carrying out a project to study measures that contribute to traffic control. As part of this project, initiatives regarding the supply of, and the demand for, transport have been examined, and a programme to disseminate information is being conducted.For further information, please contact Mr Alberto Bull .

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Traffic congestion is nothing new in Latin American cities but has worsened in recent years. Eliminating it is a pipedream, but it should be brought under control. Many economists and transport planners think electronic road pricing would be the best way of tackling it, now that the appropriate technology for implementing it is available. On the other hand, experience shows that, for political reasons, it would be better to begin by adopting simpler methods. To start with, simple road pricing would seem to be the best option. But, over 20 years of experience in London and more than six in Santiago, Chile, made it clear that socio-political barriers have to be surmounted before even this option can be applied in practice. There is more political support for measures to control parking, due in part to the fact that the legal powers do not normally extend to restricting the number of parking spaces available to high-income and influential motorists who have the right to park near their offices and who cause a great deal of the congestion whilst getting there. In Latin America, the relative importance of taxis also diminishes the effectiveness of measures geared to parking, since taxis contribute to congestion although but they do not park. The problem of congestion cannot be solved by using tame measures. The time has come for something bolder, i.e., measures that, at the very least, exercise control over those parking spaces, which so far have been beyond the reach of governments and local authorities, ideally, simple road pricing systems would be even more effective.

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The principal objective of this issue of the FAL Bulletin is to look at investments made in the Spanish port system between 1993 and 2010 in order to determine whether there is a direct link between expansion of port facilities and the outcome of competition for traffic.