According to Brazilian reports of large trucks accidents on Federal Highway, fatigue and speeding are the major contributors to those accidents in which drivers are trying to meet short delivery deadlines for long hau...According to Brazilian reports of large trucks accidents on Federal Highway, fatigue and speeding are the major contributors to those accidents in which drivers are trying to meet short delivery deadlines for long hauls. A new federal law has been approved to limit truck drivers＇ working times, including maximum continuous driving time and maximum daily and weekly on-duty time. We present a study that aims at analyzing whether the existing resting areas on federal highways have sufficient capacity to meet current and future demand for truck stops. We have established the following method： In the first step, we review and study different models found in the literature and evaluate their potential application to Brazilian conditions; In the next step, we develop our own model and, finally, validate it using data from BR-101 Federal Highway, in Santa Catarina State. Tests made using part of collected data （which were subjected to statistical treatment） showed satisfactory results, indicating that the demand behavior was consistent with that observed in the field and the answers provided by truck drivers in the interviews. The research has yet to complete processing all data and it also must be repeated in other regions with different characteristics.展开更多
The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focu...The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focuses on the importance of implementing minimum efficiency standards in Brazil and elsewhere and presents the state of the art in domestic and international legislation and standards pertaining to induction motors. It also covers advancements in motor technology, by means of an analysis of motors currently on the market, and trends in said technology, with particular emphasis on the search for new materials for permanent magnet manufacturing. The results of experimental testing of a permanent-magnet motor and a premium-efficiency induction motor are presented and discussed, with the objective of contributing to definition of the IE4 （Efficiency Level from International Electrotechnical Commission） standard and to the goal-oriented Brazilian efficiency program. The present article described the results of experimental testing with an induction motor and a line-start permanent-magnet motor and concluded that permanent-magnet motors are superior in performance to induction motors at loads between half and full, with an efficiency advantage of up to 6.7%. However, in applications with wide variations in load, with motor operation below half load, use of permanent-magnet motors is not economically feasible, as the current cost of these motors exceeds that of induction motors. Another relevant finding concerns the current harmonic distortion observed during testing. The tested permanent-magnet motor exhibited a distortion of up to 13.5%, exceeding Institute of Electrical and Electronics Engineers Standard 519/1992 recommended limits. This behavior must be clearly specified and taken into account by future standards that define the super premium class, lest the impact of harmonic distortion prove to be detrimental to industries that adopt these motors for their processes.展开更多
文摘According to Brazilian reports of large trucks accidents on Federal Highway, fatigue and speeding are the major contributors to those accidents in which drivers are trying to meet short delivery deadlines for long hauls. A new federal law has been approved to limit truck drivers＇ working times, including maximum continuous driving time and maximum daily and weekly on-duty time. We present a study that aims at analyzing whether the existing resting areas on federal highways have sufficient capacity to meet current and future demand for truck stops. We have established the following method： In the first step, we review and study different models found in the literature and evaluate their potential application to Brazilian conditions; In the next step, we develop our own model and, finally, validate it using data from BR-101 Federal Highway, in Santa Catarina State. Tests made using part of collected data （which were subjected to statistical treatment） showed satisfactory results, indicating that the demand behavior was consistent with that observed in the field and the answers provided by truck drivers in the interviews. The research has yet to complete processing all data and it also must be repeated in other regions with different characteristics.
文摘The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focuses on the importance of implementing minimum efficiency standards in Brazil and elsewhere and presents the state of the art in domestic and international legislation and standards pertaining to induction motors. It also covers advancements in motor technology, by means of an analysis of motors currently on the market, and trends in said technology, with particular emphasis on the search for new materials for permanent magnet manufacturing. The results of experimental testing of a permanent-magnet motor and a premium-efficiency induction motor are presented and discussed, with the objective of contributing to definition of the IE4 （Efficiency Level from International Electrotechnical Commission） standard and to the goal-oriented Brazilian efficiency program. The present article described the results of experimental testing with an induction motor and a line-start permanent-magnet motor and concluded that permanent-magnet motors are superior in performance to induction motors at loads between half and full, with an efficiency advantage of up to 6.7%. However, in applications with wide variations in load, with motor operation below half load, use of permanent-magnet motors is not economically feasible, as the current cost of these motors exceeds that of induction motors. Another relevant finding concerns the current harmonic distortion observed during testing. The tested permanent-magnet motor exhibited a distortion of up to 13.5%, exceeding Institute of Electrical and Electronics Engineers Standard 519/1992 recommended limits. This behavior must be clearly specified and taken into account by future standards that define the super premium class, lest the impact of harmonic distortion prove to be detrimental to industries that adopt these motors for their processes.
