WorldWideScience

Sample records for electric transit bus

  1. Hybrid Electric Transit Bus

    Science.gov (United States)

    Viterna, Larry A.

    1997-01-01

    A government, industry, and university cooperative is developing an advanced hybrid electric city transit bus. Goals of this effort include doubling the fuel economy compared to current buses and reducing emissions to one-tenth of current EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors as an energy storage system, and a planned natural gas fueled turbogenerator developed from a small jet engine. Power from both the generator and energy storage system is provided to a variable speed electric motor attached to the rear axle. At over 15000 kg gross weight, this is the largest vehicle of its kind ever built using ultra-capacitor energy storage. This paper describes the overall power system architecture, the evolution of the control strategy, and its performance over industry standard drive cycles.

  2. Foothill Transit Battery Electric Bus Demonstration Results

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Prohaska, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kelly, Kenneth [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-01-27

    Foothill Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) to evaluate its fleet of Proterra battery electric buses (BEBs) in revenue service. The focus of this evaluation is to compare performance of the BEBs to that of conventional technology and to track progress over time toward meeting performance targets. This project has also provided an opportunity for DOE to conduct a detailed evaluation of the BEBs and charging infrastructure. This report provides data on the buses from April 2014 through July 2015. Data are provided on a selection of compressed natural gas buses as a baseline comparison.

  3. Foothill Transit Battery Electric Bus Demonstration Results: Second Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jeffers, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-06-28

    This report summarizes results of a battery electric bus (BEB) evaluation at Foothill Transit, located in the San Gabriel and Pomona Valley region of Los Angeles County, California. Foothill Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory to evaluate its fleet of Proterra BEBs in revenue service. The focus of this evaluation is to compare performance of the BEBs to that of conventional technology and to track progress over time toward meeting performance targets. This project has also provided an opportunity for DOE to conduct a detailed evaluation of the BEBs and charging infrastructure. This is the second report summarizing the results of the BEB demonstration at Foothill Transit and it provides data on the buses from August 2015 through December 2016. Data are provided on a selection of compressed natural gas buses as a baseline comparison.

  4. Massachusetts Fuel Cell Bus Project: Demonstrating a Total Transit Solution for Fuel Cell Electric Buses in Boston

    Energy Technology Data Exchange (ETDEWEB)

    2017-05-22

    The Federal Transit Administration's National Fuel Cell Bus Program focuses on developing commercially viable fuel cell bus technologies. Nuvera is leading the Massachusetts Fuel Cell Bus project to demonstrate a complete transit solution for fuel cell electric buses that includes one bus and an on-site hydrogen generation station for the Massachusetts Bay Transportation Authority (MBTA). A team consisting of ElDorado National, BAE Systems, and Ballard Power Systems built the fuel cell electric bus, and Nuvera is providing its PowerTap on-site hydrogen generator to provide fuel for the bus.

  5. Air-pollution and economics: diesel bus versus electric bus

    OpenAIRE

    Adheesh, SR; Vasisht, Shravanth M; Ramasesha, Sheela K

    2016-01-01

    The Bangalore Metropolitan Transport Corporation (BMTC) took an initiative to check the overall benefits of introducing electric buses as a suitable replacement for the diesel buses to tackle the burgeoning pollution in the city of Bengaluru, India. For a trial run of three months, an electric bus was procured from a Chinese company `Build Your Dreams' (BYD). Data were collected by BMTC on the operation and maintenance of the bus. This new initiative, if rightly guided, could have a direct im...

  6. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus Preliminary Evaluation Results

    Science.gov (United States)

    2008-10-16

    This report describes operations at Connecticut Transit (CTTRANSIT) in Hartford for one prototype fuel cell bus and three new diesel buses operating from the same location. The report discusses the planned fuel cell bus demonstration and equipment us...

  7. Electrical system architecture having high voltage bus

    Science.gov (United States)

    Hoff, Brian Douglas [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL

    2011-03-22

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  8. Clean air program : design guidelines for bus transit systems using electric and hybrid electric propulsion as an alternative fuel

    Science.gov (United States)

    2003-03-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including : Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG), and : Methanol/Ethanol, are already being used. At presen...

  9. Understanding & modeling bus transit driver availability.

    Science.gov (United States)

    2014-07-01

    Bus transit agencies are required to hire extraboard (i.e. back-up) operators to account for unexpected absences. Incorrect sizing of extra driver workforce is problematic for a number of reasons. Overestimating the appropriate number of extraboard o...

  10. Scenario-based electric bus operation: A case study of Putrajaya, Malaysia

    Directory of Open Access Journals (Sweden)

    Lay Eng Teoh

    2018-03-01

    Full Text Available Globally, transportation sector has emerged as one of the major sources of air pollution. Correspondingly, green mobility (with electric bus is gaining increasing attention as an essential step to mitigate emission concern. As such, a proper electric bus network design and fleet planning is important especially for bus operator to acquire an adequate number of electric bus, right on time, in order to operate electric bus system viably. Thus, this paper aims to examine the possibility to operate electric bus as a replacement for the conventional bus operation (with natural gas buses for the study area in Putrajaya, Malaysia. In order to determine a proper-designed electric bus operating system in terms of electric bus route, service frequency and quantity, the proposed methodology is developed with the aid of a traffic modeling software to cater various scenarios. Based on the existing (conventional traffic and transit system in Putrajaya, the developed electric bus operating model is calibrated accordingly by considering various operational concerns including battery capacity and charging facility. The resultant findings revealed that the developed electric bus operating system in Putrajaya outperforms the conventional bus operation, not only in generating a higher profit margin for the bus operator, but also satisfying the passengers in a better manner (by carrying more passengers per unit of bus with a lower energy consumption.

  11. Fuel Cell Electric Bus Evaluations | Hydrogen and Fuel Cells | NREL

    Science.gov (United States)

    Bus Evaluations Fuel Cell Electric Bus Evaluations NREL's technology validation team evaluates fuel cell electric buses (FCEBs) to provide comprehensive, unbiased evaluation results of fuel cell bus early transportation applications for fuel cell technology. Buses operate in congested areas where

  12. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Preliminary Evaluation Results

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2008-10-01

    This report provides preliminary results from a National Renewable Energy Laboratory evaluation of a protoptye fuel cell transit bus operating at Connecticut Transit in Hartford. Included are descriptions of the planned fuel cell bus demonstration and equipment; early results and agency experience are also provided.

  13. BC Transit Fuel Cell Bus Project: Evaluation Results Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    This report evaluates a fuel cell electric bus demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. This evaluation report covers two years of revenue service data on the buses from April 2011 through March 2013.

  14. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Third Evaluation Report and Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2010-01-01

    This report describes operations at Connecticut Transit (CTTRANSIT) in Hartford for one prototype fuel cell bus and three new diesel buses operating from the same location. The prototype fuel cell bus was manufactured by Van Hool and ISE Corp. and features an electric hybrid drive system with a UTC Power PureMotion 120 Fuel Cell Power System and ZEBRA batteries for energy storage. The fuel cell bus started operation in April 2007, and evaluation results through October 2009 are provided in this report.

  15. BC Transit Fuel Cell Bus Project Evaluation Results: Second Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Post, M.

    2014-09-01

    Second report evaluating a fuel cell electric bus (FCEB) demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. NREL published its first report on the demonstration in February 2014. This report is an update to the previous report; it covers 3 full years of revenue service data on the buses from April 2011 through March 2014 and focuses on the final experiences and lessons learned.

  16. Brazilian hybrid electric fuel cell bus

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, P.E.V.; Carreira, E.S. [Coppe-Federal Univ. of Rio de Janeiro (Brazil). Hydrogen Lab.

    2010-07-01

    The first prototype of a hybrid electric fuel cell bus developed with Brazilian technology is unveiled. It is a 12 m urban-type, low-floor, air-conditioned bus that possesses three doors, air suspension, 29 seats and reversible wheelchair site. The bus body was built based on a double-deck type monoblock vehicle that is able to sustain important load on its roof. This allowed positioning of the type 3 hydrogen tanks and the low weight traction batteries on the roof of the vehicles without dynamic stabilization problems. A novel hybrid energy configuration was designed in such a way that the low-power (77 kWe) fuel cell works on steady-state operation mode, not responding directly to the traction motor load demand. The rate of kinetic energy regeneration upon breaking was optimized by the use of an electric hybrid system with predominance of batteries and also by utilizing supercapacitors. The electric-electronic devices and the security control softwares for the auxiliary and traction systems were developed in-house. The innovative hybrid-electric traction system configuration led to the possibility to decrease the fuel cell power, with positive impact on weight and system volume reduction, as well as to significantly decrease the hydrogen consumption. (orig.)

  17. Bus bar electrical feedthrough for electrorefiner system

    Science.gov (United States)

    Williamson, Mark; Wiedmeyer, Stanley G; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2013-12-03

    A bus bar electrical feedthrough for an electrorefiner system may include a retaining plate, electrical isolator, and/or contact block. The retaining plate may include a central opening. The electrical isolator may include a top portion, a base portion, and a slot extending through the top and base portions. The top portion of the electrical isolator may be configured to extend through the central opening of the retaining plate. The contact block may include an upper section, a lower section, and a ridge separating the upper and lower sections. The upper section of the contact block may be configured to extend through the slot of the electrical isolator and the central opening of the retaining plate. Accordingly, relatively high electrical currents may be transferred into a glovebox or hot-cell facility at a relatively low cost and higher amperage capacity without sacrificing atmosphere integrity.

  18. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2013-01-01

    SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and help determine the progress toward technology readiness. NREL has previously published three reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from February 2012 through November 2012.

  19. Development of a multi-mode hybrid electric bus

    Energy Technology Data Exchange (ETDEWEB)

    Shemmans, M.J. [Overland Custom Coach, Thorndale, ON (Canada); Bland, C. [BET Services Inc., Mississauga, ON (Canada)

    2004-04-01

    This paper describes the development of an energy efficient, low floor, 28 foot hybrid electric bus for use as an airport shuttle bus or other specialized transit operations. A multi-mode concept was also adopted to include the capability of operating in battery-only drive, engine-only drive or a range of hybrid electric drive modes. The electric drivetrain was powered by a battery pack or a combination of a battery pack and an internal combustion engine-powered electric generator. The participating companies in this project include Overland Custom Coach, BET Services Inc., Siemens and Transport Canada. The technical feasibility study was described with reference to duty cycles, performance issues, vehicle weight, mechanical drive issues, brakes, suspension, powertrain cooling, heating, ventilation, electrical system, batteries and control system. The commercial feasibility was also described in terms of capital and operating costs. Results of the prototype tests validate the possibilities of zero or reduced emission transit in real world applications. 25 tabs., 32 figs.

  20. Elimination of bus voltage impact on temperature sensitive electrical parameter during turn-on transition for junction temperature estimation of high-power IGBT modules

    DEFF Research Database (Denmark)

    Luo, Haoze; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    Junction temperature is of great importance to safe operating area of IGBT modules. Various information of the IGBT operating state is reflected on electrical characteristics during turn-on transient. A unified extraction method for internal junction temperature via dynamic thermo......-sensitive electrical parameters (DTSEP) during turn-on transient is proposed. Two DTSEP, turn-on delay time (tdon) and the maximum increasing rate of collector current dic/dt(max), are combined to eliminate the bus voltage impact. Using the inherent emitter-auxiliary inductor LeE in high-power modules, the temperature......-dependent DTSEPs can be converted into a low-voltage and measurable signal. Finally, experiment results are exhibited to verify the effectiveness of proposed method....

  1. Optimization of transit bus fleet's life cycle assessment impacts with alternative fuel options

    International Nuclear Information System (INIS)

    Ercan, Tolga; Zhao, Yang; Tatari, Omer; Pazour, Jennifer A.

    2015-01-01

    Public transportation is one of the most promising transportation modes to reduce the environmental emissions of the transportation sector in the U.S. In order to mitigate the environmental impacts brought by the transit bus system, new energy buses are introduced into the vehicle market. The goal of this study is to find an optimal bus fleet combination for different driving conditions to minimize life cycle cost, greenhouse gas emissions, and conventional air pollutant emission impacts. For this purpose, a Multi-Objective Linear Programming approach is used to select the optimum bus fleet combinations. Given different weight scenarios, this method could effectively provide solutions for decision makers with various budget constraints or emission reduction requirements. The results indicate that in heavily congested driving cycles such as the Manhattan area, the battery electric bus is the dominant vehicle type, while the hybrid bus has more balanced performances in most scenarios because of its lower initial investment comparing to battery electric buses. Petroleum powered buses have seldom been selected by the model. The trade-off analysis shows that the overall greenhouse gas impact performance is sensitive to the life cycle cost after certain points, which could provide valuable information for the bus fleet combination planning. - Highlights: • Hybrid-Life Cycle Assessment analysis approach for transit bus operations. • Optimizing the economic and sustainability impacts of transit bus fleet operation. • CO 2 emissions and other air pollutants related health and environmental damage cost. • Trade-offs between CO 2 emissions and cost of transit bus fleet operation.

  2. Transit bus applications of lithium ion batteries : progress and prospects

    Science.gov (United States)

    2012-12-31

    This report provides an overview of diverse transit bus applications of advanced Lithium Ion Batteries (LIBs). The report highlights and illustrates several FTA programs that fostered the successful development, demonstration, and deployment of fuel-...

  3. King County Metro Battery Electric Bus Demonstration: Preliminary Project Results

    Energy Technology Data Exchange (ETDEWEB)

    2017-05-22

    The U.S. Federal Transit Administration (FTA) funds a variety of research projects that support the commercialization of zero-emission bus technology. To evaluate projects funded through these programs, FTA has enlisted the help of the National Renewable Energy Laboratory (NREL) to conduct third-party evaluations of the technologies deployed under the FTA programs. NREL works with the selected agencies to evaluate the performance of the zero-emission buses compared to baseline conventional buses in similar service. The evaluation effort will advance the knowledge base of zero-emission technologies in transit bus applications and provide 'lessons learned' to aid other fleets in incrementally introducing next generation zero-emission buses into their operations. This report provides preliminary performance evaluation results from a demonstration of three zero-emission battery electric buses at King County Metro in King County, Washington. NREL developed this preliminary results report to quickly disseminate evaluation results to stakeholders. Detailed evaluation results will be published in future reports.

  4. Transition to a hydrogen fuel cell transit bus fleet for Canadian urban transit system

    International Nuclear Information System (INIS)

    Ducharme, P.

    2004-01-01

    'Full text:' The Canadian Transportation Fuel Cell Alliance (CTFCA), created by the Canadian Government as part of its 2000 Climate Change Action Plan, has commissioned MARCON-DDM's Hydrogen Intervention Team (HIT) to provide a roadmap for urban transit systems that wish to move to hydrogen fuel cell-powered bus fleets. HIT is currently in the process of gathering information from hydrogen technology providers, bus manufacturers, fuelling system providers and urban transit systems in Canada, the US and Europe. In September, HIT will be in a position to provide a preview of its report to the CTFCA, due for October 2004. The planned table of contents includes: TOMORROW'S FUEL CELL (FC) URBAN TRANSIT BUS - Powertrain, on-board fuel technologies - FC engine system manufacturers - Bus technical specifications, performances, operating characteristics - FC bus manufacturers TOMORROW'S FC TRANSIT PROPERTY - Added maintenance, facilities and fuelling infrastructure requirements - Supply chain implications - Environmental and safety issues - Alternative operational concepts PATHWAYS TO THE FUTURE - Choosing the future operational concept - 'Gap' assessment - how long from here to there? - Facilities and fleet adjustments, including fuelling infrastructure - Risk mitigation, code compliance measures TRANSITIONAL CONSIDERATIONS - Cost implications - Transition schedule (author)

  5. Regenerative Braking System for Series Hybrid Electric City Bus

    OpenAIRE

    Zhang, Junzhi; Lu, Xin; Xue, Junliang; Li, Bos

    2008-01-01

    Regenerative Braking Systems (RBS) provide an efficient method to assist hybrid electric buses achieve better fuel economy while lowering exhaust emissions. This paper describes the design and testing of three regenerative braking systems, one of which is a series regenerative braking system and two of which are parallel regenerative braking systems. The existing friction based Adjustable Braking System (ABS) on the bus is integrated with each of the new braking systems in order to ensure bus...

  6. Scenario-based electric bus operation: A case study of Putrajaya, Malaysia

    OpenAIRE

    Lay Eng Teoh; Hooi Ling Khoo; Siew Yoke Goh; Lai Mun Chong

    2018-01-01

    Globally, transportation sector has emerged as one of the major sources of air pollution. Correspondingly, green mobility (with electric bus) is gaining increasing attention as an essential step to mitigate emission concern. As such, a proper electric bus network design and fleet planning is important especially for bus operator to acquire an adequate number of electric bus, right on time, in order to operate electric bus system viably. Thus, this paper aims to examine the possibility to oper...

  7. Economic impacts of bus rapid transit in southeast Michigan.

    Science.gov (United States)

    2015-12-01

    In recent years, Bus Rapid Transit (BRT) has generated great interest across the United States. There are more than 20 BRT : systems in existence, and more are in the planning stage (including in Detroit). Within the next few years, BRT will be plann...

  8. Bus Rapid Transit and Socioeconomic Condition of Bus Commuters in Lagos State

    Directory of Open Access Journals (Sweden)

    Owolabi L. Kuye

    2017-10-01

    Full Text Available Road transport is one of the most common means of transportation across the world. Bus transportation in Nigeria had witnessed many problems for the past decades considering the growing population with the attendant loss of lives and properties in most cities like Lagos in Nigeria. This paper focuses on the adequacy of services provided by Bus Rapid Transit (BRT in Lagos State with respect to the extent to which it influences the socioeconomic conditions of bus commuters. It examines the effect of services rendered by BRT on cost reduction potential, income and safety. Multistage sampling technique was used to select 20 samples each from all respondents in all local government area in Lagos State to reach a total of three hundred and thirty (330 samples. The data collection instrument was the questionnaire which was validated. Data collected were analysed with the use of descriptive statistics such as means, percentages and standard deviation and inferential statistics such as regression and analysis of variance techniques. Findings showed that BRT services has reduced the cost of bus commuters and also increased safety and security thereby increasing the socioeconomic condition of Lagosians. The study recommends improvements in BRT services through the deployment of technology as it had been used in developed countries.

  9. Energy efficient motion control of the electric bus on route

    Science.gov (United States)

    Kotiev, G. O.; Butarovich, D. O.; Kositsyn, B. B.

    2018-02-01

    At present, the urgent problem is the reduction of energy costs of urban motor transport. The article proposes a method of solving this problem by developing an energy-efficient law governing the movement of an electric bus along a city route. To solve this problem, an algorithm is developed based on the dynamic programming method. The proposed method allows you to take into account the constraints imposed on the phase coordinates, control action, as well as on the time of the route. In the course of solving the problem, the model of rectilinear motion of an electric bus on a horizontal reference surface is considered, taking into account the assumptions that allow it to be adapted for the implementation of the method. For the formation of a control action in the equations of motion dynamics, an algorithm for changing the traction / braking torque on the wheels of an electric bus is considered, depending on the magnitude of the control parameter and the speed of motion. An optimal phase trajectory was obtained on a selected section of the road for the prototype of an electric bus. The article presents the comparison of simulation results obtained with the optimal energy efficient control law with the results obtained by a test driver. The comparison proved feasibility of the energy efficient control law for the automobile city electric transport.

  10. Departure Interval Optimization of Electric Bus Rapid Transit Considering Level of Service%考虑服务水平的纯电动快速公交发车间隔优化研究

    Institute of Scientific and Technical Information of China (English)

    王雪然; 刘文峰; 李斌; 张沫

    2017-01-01

    With the electric vehicles applied in the field of bus rapid transit,due to the special operational needs of charging or battery swap for electric vehicles,the traditional methods of departure interval optimization are no longer applicable.Considering the level of service and charging time constraints,this paper studies the departure interval optimization of electric bus rapid transit.Firstly,the service level evaluation system associated with energy consumption is established by analyzing the correlation between service level indexes and energy consumption;secondly,considering the level of service and charging time constraints,the departure interval optimization model is established by setting energy consumption as the objective function;finally,taking line 1 of Jinhua E-BRT as an example to examine the effect of the optimization model,the optimization results demonstrate that compared with the current operation plans the energy consumption is saved by 6.21% under the premise of the same level of service.Therefore,the departure interval optimization method of electric bus rapid transit considering level of service established in this paper has certain practical significance and provides an important guidance for reducing the energy consumption under a certain service level.%随着电动汽车被引入城市快速公交领域,由于其充换电等特殊的运营调度需求,在发车间隔计划等制定过程中传统方法不再适用.本文在综合考虑服务水平和车辆充电时间约束条件下,对纯电动快速公交(E-BRT)发车间隔优化进行了研究.根据分析服务水平指标项与车辆能耗的相关性,建立了面向能耗评估的服务水平评价体系;综合考虑服务水平和充电时间约束条件,以车辆运营能耗为目标函数,建立了发车间隔优化模型;基于金华市E-BRT1号线运营数据进行实例验证,结果表明,在满足相同服务水平情况下,本文提出的优化模型可以节约能耗6.21%.

  11. Developing a viable electric bus service: the Milton Keynes demonstration project

    OpenAIRE

    Miles, John; Potter, Stephen

    2014-01-01

    Buses can be a serious source of city centre air pollution. Electric buses deliver zero emissions but, because of the time required to recharge, more buses are needed for a given timetable than diesel counterparts, so making mainstream electric bus operations prohibitively expensive.\\ud \\ud Early 2014 saw the implementation in Milton Keynes of an electric bus service designed to overcome this problem. An entire bus route has been converted to electric operation with inductive charging at bus ...

  12. American fuel cell bus project : first analysis report.

    Science.gov (United States)

    2013-06-01

    This report summarizes the experience and early results from the American Fuel Cell Bus Project, a fuel cell electric bus demonstration : funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by CALST...

  13. Discharging a DC bus capacitor of an electrical converter system

    Science.gov (United States)

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  14. Safety evaluation of a hydrogen fueled transit bus

    Energy Technology Data Exchange (ETDEWEB)

    Coutts, D.A.; Thomas, J.K.; Hovis, G.L.; Wu, T.T. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-12-31

    Hydrogen fueled vehicle demonstration projects must satisfy management and regulator safety expectations. This is often accomplished using hazard and safety analyses. Such an analysis has been completed to evaluate the safety of the H2Fuel bus to be operated in Augusta, Georgia. The evaluation methods and criteria used reflect the Department of Energy`s graded approach for qualifying and documenting nuclear and chemical facility safety. The work focused on the storage and distribution of hydrogen as the bus motor fuel with emphases on the technical and operational aspects of using metal hydride beds to store hydrogen. The safety evaluation demonstrated that the operation of the H2Fuel bus represents a moderate risk. This is the same risk level determined for operation of conventionally powered transit buses in the United States. By the same criteria, private passenger automobile travel in the United States is considered a high risk. The evaluation also identified several design and operational modifications that resulted in improved safety, operability, and reliability. The hazard assessment methodology used in this project has widespread applicability to other innovative operations and systems, and the techniques can serve as a template for other similar projects.

  15. Economic Optimization Analysis of Chengdu Electric Community Bus Operation

    Science.gov (United States)

    Yidong, Wang; Yun, Cai; Zhengping, Tan; Xiong, Wan

    2018-03-01

    In recent years, the government has strongly supported and promoted electric vehicles and has given priority to demonstration and popularization in the field of public transport. The economy of public transport operations has drawn increasing attention. In this paper, Chengdu wireless charging pure electric community bus is used as the research object, the battery, air conditioning, driver’s driving behavior and other economic influence factors were analyzed, and optimizing the operation plan through case data analysis, through the reasonable battery matching and mode of operation to help businesses effectively save operating costs and enhance economic efficiency.

  16. Electric bus migration in Bengaluru with dynamic charging technologies

    Directory of Open Access Journals (Sweden)

    Ankit Kumar Begwani

    2017-12-01

    Full Text Available Rapid but unplanned urban development coupled with economic growth has resulted in congestion and pollution concerns in Indian cities. This forced India consider taking concrete steps towards design policies that would help stir the nation towards a more sustainable future. India, along with other bigger Asian economies like China, needs to address the growing global concerns over climate change and design their framework and policies to help cut down the greenhouse gas emissions. Transportation is a major source of pollution. A shift towards a pro-public transport policy would solve the traffic congestion problems and address the emission concerns. India has a significantly higher modal share of public transportation in its major cities. Public bus transport system acts as a lifeline to the India’s poor and middle class citizens. The following study focuses on the need for a replacement of conventional fossil fuel dependent buses with Electric buses in the existing public transport bus fleet in the city of Bengaluru. A design has been developed to utilize wireless charging technologies to realize electric bus migration in Bengaluru.

  17. Electric bus fleet size and mix problem with optimization of charging infrastructure

    DEFF Research Database (Denmark)

    Rogge, Matthias; van der Hurk, Evelien; Larsen, Allan

    2018-01-01

    Battery electric buses are seen as a well-suited technology for the electrification of road-based public transport. However, the transition process from conventional diesel to electric buses faces major hurdles caused by range limitations and required charging times of battery buses. This work...... addresses these constraints and provides a methodology for the cost-optimized planning of depot charging battery bus fleets and their corresponding charging infrastructure. The defined problem covers the scheduling of battery buses, the fleet composition, and the optimization of charging infrastructure...... in a joint process. Vehicle schedule adjustments are monetized and evaluated together with the investment and operational costs of the bus system. The resulting total cost of ownership enables a comparison of technical alternatives on a system level, which makes this approach especially promising...

  18. Successfulness of bus rapid transit systems in Asia. Ex-post evaluation

    NARCIS (Netherlands)

    Kogdenko, Nadja

    2010-01-01

    SUMMARY Bus Rapid Transit (BRT) can be defined as “a bus-based mass transit system that delivers fast, comfortable, and cost-effective urban mobility”. It offers the opportunity to create a high-quality mass transit system at affordable costs, which is p

  19. Optimal energy management for a series-parallel hybrid electric bus

    International Nuclear Information System (INIS)

    Xiong Weiwei; Zhang Yong; Yin Chengliang

    2009-01-01

    This paper aims to present a new type of series-parallel hybrid electric bus and its energy management strategy. This hybrid bus is a post-transmission coupled system employing a novel transmission as the series-parallel configuration switcher. In this paper, the vehicle architecture, transmission scheme and numerical models are presented. The energy management system governs the mode switching between the series mode and the parallel mode as well as the instantaneous power distribution. In this work, two separated controllers using fuzzy logic called Mode Decision and Parallel-driving Energy Management are employed to fulfill these two tasks. The energy management strategy and the applications of fuzzy logic are described. The strategy is validated by a forward-facing simulation program based on the software Matlab/Simulink. The results show that the energy management strategy is effective to control the engine operating in a high-efficiency region as well as to sustain the battery charge state while satisfy the drive ability. The energy consumption is theoretically reduced by 30.3% to that of the conventional bus under transit bus driving cycle. In addition, works need future study are also presented.

  20. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  1. Evolution of weighted complex bus transit networks with flow

    Science.gov (United States)

    Huang, Ailing; Xiong, Jie; Shen, Jinsheng; Guan, Wei

    2016-02-01

    Study on the intrinsic properties and evolutional mechanism of urban public transit networks (PTNs) has great significance for transit planning and control, particularly considering passengers’ dynamic behaviors. This paper presents an empirical analysis for exploring the complex properties of Beijing’s weighted bus transit network (BTN) based on passenger flow in L-space, and proposes a bi-level evolution model to simulate the development of transit routes from the view of complex network. The model is an iterative process that is driven by passengers’ travel demands and dual-controlled interest mechanism, which is composed of passengers’ spatio-temporal requirements and cost constraint of transit agencies. Also, the flow’s dynamic behaviors, including the evolutions of travel demand, sectional flow attracted by a new link and flow perturbation triggered in nearby routes, are taken into consideration in the evolutional process. We present the numerical experiment to validate the model, where the main parameters are estimated by using distribution functions that are deduced from real-world data. The results obtained have proven that our model can generate a BTN with complex properties, such as the scale-free behavior or small-world phenomenon, which shows an agreement with our empirical results. Our study’s results can be exploited to optimize the real BTN’s structure and improve the network’s robustness.

  2. An evaluation of a lane support system for bus rapid transit on narrow shoulders and the relation to bus driver mental workload

    NARCIS (Netherlands)

    Ward, Nicholas J.; Shankwitz, Craig; Gorgestani, Alec; Donath, Max; De Waard, Dick; Boer, Erwin R.

    2006-01-01

    The use of dedicated bus shoulders is a key method for implementing bus rapid transit (BRT) in areas that do not have the space for additional infrastructure. However, the narrow width of the bus shoulder and the need to anticipate traffic hazards in the adjacent lane can both be significant

  3. Bus rapid transit and development : policies and practices that affect development around transit.

    Science.gov (United States)

    2009-12-01

    The development of Bus Rapid Transit (BRT) systems is relatively recent in the United States, but several systems are in operation and more are advancing. There is a need for a more comprehensive understanding of the relationship between land use and...

  4. SunLine Transit Agency Fuel Cell Transit Bus: Fourth Evaluation Report (Report and Appendices)

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2009-01-01

    This report describes operations at SunLine Transit Agency for a prototype fuel cell bus and five new compressed natural gas (CNG) buses. This is the fourth evaluation report for this site, and it describes results and experiences from April 2008 through October 2008. These results are an addition to those provided in the previous three evaluation reports.

  5. SunLine Transit Agency Fuel Cell Transit Bus: Fifth Evaluation Report (Report and Appendices)

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2009-08-01

    This report describes operations at SunLine Transit Agency for a prototype fuel cell bus and five compressed natural gas (CNG) buses. This is the fifth evaluation report for this site, and it describes results and experiences from October 2008 through June 2009. These results are an addition to those provided in the previous four evaluation reports.

  6. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Second Evaluation Report and Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2009-05-01

    This report describes operations at Connecticut Transit (CTTRANSIT) in Hartford for one prototype fuel cell bus and three new diesel buses operating from the same location. The evaluation period in this report (January 2008 through February 2009) has been chosen to coincide with a UTC Power propulsion system changeout that occurred on January 15, 2008.

  7. Kajian Implementasi Graph Database pada Rute Bus Rapid Transit

    Directory of Open Access Journals (Sweden)

    Panji Wisnu Wirawan

    2017-12-01

    Full Text Available Bus Rapid Transit (BRT merupakan salah satu sarana transportasi publik yang memiliki rute perjalanan tertentu atau disebut sebagai koridor. Satu koridor BRT dengan koridor yang lain bukanlah koridor yang terpisah, melainkan saling terhubung. Dalam melakukan perjalanan, penumpang BRT boleh jadi melakukan perpindahan koridor melalui shelter. Informasi tersebut perlu didapatkan seorang calon penumpang sebelum melakukan perjalanan supaya tidak terjadi perpindahan koridor yang salah. Teknologi informasi memungkinkan representasi informasi pencarian koridor yang tepat ketika penumpang akan melakukan sebuah perjalanan, terlebih dengan hadirnya graph database. Graph Database memungkinkan representasi BRT yang baik karena sifat graph yang secara standar telah menunjukkan node dan relationship. Artikel ini mengkaji penerapan graph database untuk data pada BRT. Selain itu, artikel ini mendesain sebuah algoritma pencarian koridor BRT. Harapannya, algoritma tersebut dapat digunakan untuk membangun aplikasi yang memanfaatkan data pada graph database. Hasil kajian menunjukkan bahwa graph database dapat diterapkan untuk data BRT dan algoritma yang dibangun dapat digunakan untuk menyajikan informasi rute sekaligus menyampaikan informasi perpindahan koridor.

  8. Multi Bus DC-DC Converter in Electric Hybrid Vehicles

    Science.gov (United States)

    Krithika, V.; Subramaniam, C.; Sridharan, R.; Geetha, A.

    2018-04-01

    This paper is cotncerned with the design, simulation and fabrication of the prototype of a Multi bus DC- DC converter operating from 42V DC and delivering 14V DC and 260V DC. As a result, three DC buses are interconnected through a single power electronic circuitry. Such a requirement is energized in the development of a hybrid electric automobile which uses the technology of fuel cell. This is implemented by using a Bidirectional DC-DC converter configuration which is ideally suitable for multiple outputs with mutual electrical isolation. For the sake of reduced size and cost of step-up transformer, selection of a high frequency switching cycle at 10 KHz was done.

  9. National Fuel Cell Bus Program: Accelerated Testing Evaluation Report and Appendices, Alameda-Contra Costa Transit District (AC Transit)

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2009-01-01

    This is an evaluation of hydrogen fuel cell transit buses operating at AC Transit in revenue service since March 20, 2006 compared to similar diesel buses operating from the same depot. This evaluation report includes results from November 2007 through October 2008. Evaluation results include implementation experience, fueling station operation, fuel cell bus operations at Golden Gate Transit, and evaluation results at AC Transit (bus usage, availability, fuel economy, maintenance costs, and roadcalls).

  10. Analysis of a diesel-electric hybrid urban bus system

    Science.gov (United States)

    Marr, W. W.; Sekar, R. R.; Ahlheim, M. C.

    A hybrid bus powered by a diesel engine and a battery pack was analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, were evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

  11. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Third Results Reports

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2012-05-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. NREL has previously published two reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from July 2011 through January 2012.

  12. Research on a Novel Hydraulic/Electric Synergy Bus

    Directory of Open Access Journals (Sweden)

    Kegang Zhao

    2017-12-01

    Full Text Available In recent years, increasing concerns regarding environmental pollution and requirements for lower fossil fuel consumption have increased interest in alternative hybrid powertrains. As a result, this paper presents a novel hydraulic/electric synergy powertrain with multiple working modes. The three energy sources (i.e., engine, battery, and hydraulic accumulator in this configuration are regulated by a dual planetary gear set to achieve optimal performances. This paper selects the component sizes of a hybrid electric vehicle (HEV, a hydraulic hybrid vehicle (HHV, and a hydraulic/electric synergy vehicle (HESV, based on the dynamic performance of a target vehicle (TV. In addition, this paper develops the forward simulation models of the four aforementioned vehicles in the MATLAB/Simulink/Driveline platform, in which the fuel economy simulations are carried out in relation to the Chinese urban bus cycle. The simulation results show that the fuel consumption of the three hybrid vehicles is similar, but much better than, that of the TV. Finally, based on the operating cost calculations over a five-year working period, the lowest cost ranges of the three hybrid vehicles are determined, which provides a method for choosing the optimal hybrid scheme.

  13. Bus Operation Monitoring Oriented Public Transit Travel Index System and Calculation Models

    Directory of Open Access Journals (Sweden)

    Jiancheng Weng

    2013-01-01

    Full Text Available This study proposed a two-dimensional index system which is concerned essentially with urban travel based on travel modes and user satisfaction. First, the public transit was taken as an example to describe the index system establishing process. In consideration of convenience, rapid, reliability, comfort, and safety, a bus service evaluation index system was established. The indicators include the N-minute coverage of bus stops, average travel speed, and fluctuation of travel time between stops and bus load factor which could intuitively describe the characteristics of public transport selected to calculate bus travel indexes. Then, combined with the basic indicators, the calculation models of Convenience Index (CI, Rapid Index (RI, Reliability Index (RBI, and Comfort Index (CTI were established based on the multisource data of public transit including the real-time bus GPS data and passenger IC card data. Finally, a case study of Beijing bus operation evaluation and analysis was conducted by taking real bus operation data including GPS data and passenger transaction recorder (IC card data. The results showed that the operation condition of the public transit was well reflected and scientifically classified by the bus travel index models.

  14. The Development and Verification of a Novel ECMS of Hybrid Electric Bus

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2014-01-01

    Full Text Available This paper presents the system modeling, control strategy design, and hardware-in-the-loop test for a series-parallel hybrid electric bus. First, the powertrain mathematical models and the system architecture were proposed. Then an adaptive ECMS is developed for the real-time control of a hybrid electric bus, which is investigated and verified in a hardware-in-the-loop simulation system. The ECMS through driving cycle recognition results in updating the equivalent charge and discharge coefficients and extracting optimized rules for real-time control. This method not only solves the problems of mode transition frequently and improves the fuel economy, but also simplifies the complexity of control strategy design and provides new design ideas for the energy management strategy and gear-shifting rules designed. Finally, the simulation results show that the proposed real-time A-ECMS can coordinate the overall hybrid electric powertrain to optimize fuel economy and sustain the battery SOC level.

  15. City of Fresno peer exchange on bus rapid transit : a TPCB peer exchange

    Science.gov (United States)

    2013-09-11

    This report highlights key recommendations and best practices identified at the peer exchange on Bus Rapid Transit (BRT), held on May 21 and May 22, 2013, in Fresno, California. This event was sponsored by the Transportation Planning Capacity Buildin...

  16. State and Federal project development procedures for bus rapid transit : managing differences and reducing implementation delays

    Science.gov (United States)

    2011-08-01

    This report documents an investigation into the transportation project development process in the : context of the implementation of bus rapid transit systems on the State Highway System as well as such : systems being part of the Federal New Starts ...

  17. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2011-10-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

  18. Optimizing Bus Frequencies under Uncertain Demand: Case Study of the Transit Network in a Developing City

    Directory of Open Access Journals (Sweden)

    Zhengfeng Huang

    2013-01-01

    Full Text Available Various factors can make predicting bus passenger demand uncertain. In this study, a bilevel programming model for optimizing bus frequencies based on uncertain bus passenger demand is formulated. There are two terms constituting the upper-level objective. The first is transit network cost, consisting of the passengers’ expected travel time and operating costs, and the second is transit network robustness performance, indicated by the variance in passenger travel time. The second term reflects the risk aversion of decision maker, and it can make the most uncertain demand be met by the bus operation with the optimal transit frequency. With transit link’s proportional flow eigenvalues (mean and covariance obtained from the lower-level model, the upper-level objective is formulated by the analytical method. In the lower-level model, the above two eigenvalues are calculated by analyzing the propagation of mean transit trips and their variation in the optimal strategy transit assignment process. The genetic algorithm (GA used to solve the model is tested in an example network. Finally, the model is applied to determining optimal bus frequencies in the city of Liupanshui, China. The total cost of the transit system in Liupanshui can be reduced by about 6% via this method.

  19. Cloud computing-based energy optimization control framework for plug-in hybrid electric bus

    International Nuclear Information System (INIS)

    Yang, Chao; Li, Liang; You, Sixiong; Yan, Bingjie; Du, Xian

    2017-01-01

    Considering the complicated characteristics of traffic flow in city bus route and the nonlinear vehicle dynamics, optimal energy management integrated with clustering and recognition of driving conditions in plug-in hybrid electric bus is still a challenging problem. Motivated by this issue, this paper presents an innovative energy optimization control framework based on the cloud computing for plug-in hybrid electric bus. This framework, which includes offline part and online part, can realize the driving conditions clustering in offline part, and the energy management in online part. In offline part, utilizing the operating data transferred from a bus to the remote monitoring center, K-means algorithm is adopted to cluster the driving conditions, and then Markov probability transfer matrixes are generated to predict the possible operating demand of the bus driver. Next in online part, the current driving condition is real-time identified by a well-trained support vector machine, and Markov chains-based driving behaviors are accordingly selected. With the stochastic inputs, stochastic receding horizon control method is adopted to obtain the optimized energy management of hybrid powertrain. Simulations and hardware-in-loop test are carried out with the real-world city bus route, and the results show that the presented strategy could greatly improve the vehicle fuel economy, and as the traffic flow data feedback increases, the fuel consumption of every plug-in hybrid electric bus running in a specific bus route tends to be a stable minimum. - Highlights: • Cloud computing-based energy optimization control framework is proposed. • Driving cycles are clustered into 6 types by K-means algorithm. • Support vector machine is employed to realize the online recognition of driving condition. • Stochastic receding horizon control-based energy management strategy is designed for plug-in hybrid electric bus. • The proposed framework is verified by simulation and hard

  20. Biobjective Optimization and Evaluation for Transit Signal Priority Strategies at Bus Stop-to-Stop Segment

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-01-01

    Full Text Available This paper proposes a new optimization framework for the transit signal priority strategies in terms of green extension, red truncation, and phase insertion at the stop-to-stop segment of bus lines. The optimization objective is to minimize both passenger delay and the deviation from bus schedule simultaneously. The objective functions are defined with respect to the segment between bus stops, which can include the adjacent signalized intersections and downstream bus stops. The transit priority signal timing is optimized by using a biobjective optimization framework considering both the total delay at a segment and the delay deviation from the arrival schedules at bus stops. The proposed framework is evaluated using a VISSIM model calibrated with field traffic volume and traffic signal data of Caochangmen Boulevard in Nanjing, China. The optimized TSP-based phasing plans result in the reduced delay and improved reliability, compared with the non-TSP scenario under the different traffic flow conditions in the morning peak hour. The evaluation results indicate the promising performance of the proposed optimization framework in reducing the passenger delay and improving the bus schedule adherence for the urban transit system.

  1. Thermo-electric Analysis of the Interconnection of the LHC main Superconducting Bus Bars

    CERN Document Server

    Granieri, P P; Casali, M; Bottura, L; Siemko, A

    2013-01-01

    Spurred by the question of the maximum allowable energy for the operation of the Large Hadron Collider (LHC), we have progressed in the understanding of the thermo-electric behavior of the 13 kA superconducting bus bars interconnecting its main magnets. A deep insight of the underlying mechanisms is required to ensure the protection of the accelerator against undesired effects of resistive transitions. This is especially important in case of defective interconnections which can jeopardize the operation of the whole LHC. In this paper we present a numerical model of the interconnections between the main dipole and quadrupole magnets, validated against experimental tests of an interconnection sample with a purposely built-in defect. We consider defective interconnections featuring a lack of bonding among the superconducting cables and the copper stabilizer components, such as those that could be present in the machine. We evaluate the critical defect length limiting the maximum allowable current for powering th...

  2. Transit experience with hydrogen fueled hybrid electric buses

    International Nuclear Information System (INIS)

    Scott, P.B.; Mazaika, D.M.; Levin, J.; Edwards, T.

    2006-01-01

    Both AC Transit and SunLine Transit operate hybrid electric hydrogen fueled buses in their transit service. ACT presently operates three fuel cell buses in daily revenue service, and SunLine operates a fuel cell bus and a HHICE (Hybrid Hydrogen Internal Combustion Engine) bus. All these buses use similar electric drive train and electric accessories, although the detailed design differs notably between the fuel cell and the hybrid ICE buses. The fuel cell buses use a 120kW UTC fuel cell and a Van Hool Chassis, whereas the HHICE bus uses a turbocharged Ford engine which is capable of 140kW generator output in a New Flyer Chassis. The HHICE bus was the first in service, and has been subjected to both winter testing in Manitoba, Canada and summer testing in the Palm Springs, CA region. The winter testing included passenger sampling using questionnaires to ascertain passenger response. The fuel cell buses were introduced to service at the start of 2006. All five buses are in daily revenue service use. The paper will describe the buses and the experience of the transit properties in operating the buses. (author)

  3. Ecodriving for Reduction of Bus Transit Emission with Vehicle’s Hybrid Dynamic Model

    Directory of Open Access Journals (Sweden)

    Xiuzheng Zheng

    2015-01-01

    Full Text Available This paper formulates a global ecodriving optimal control to advise the green driving speed for bus transit to minimize the exhaust emission using Vehicle-to-Infrastructure (V2I communication. Assuming communication between vehicles and infrastructure (V2I and knowledge of traffic signal timings and waiting passengers at stations are known, an optimal driving speed is proposed to minimize the total vehicle emissions of the bus route. The dwell time of the bus transit at each station which includes two parts is proposed. A traffic lights timing model is employed as constraints to control the formation of the green wave band. Vehicle specific power (VSP model is further applied to evaluate the exhaust emission level linked with the speed and acceleration of the bus transit. An approximate sixteen-kilometer traffic network including fourteen intersections and fifteen stations of Beijing bus transit line 1 in Chaoyang District, Beijing, is chosen to investigate the performance of the developed ecodriving approach.

  4. Savannah River bus project

    Energy Technology Data Exchange (ETDEWEB)

    Summers, W.A. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1998-08-01

    The H2Fuel Bus is the world`s first hybrid hydrogen electric transit bus. It was developed through a public/private partnership involving several leading technology and industrial organizations in the Southeast, with primary funding and program management provided by the Department of Energy. The primary goals of the project are to gain valuable information on the technical readiness and economic viability of hydrogen buses and to enhance the public awareness and acceptance of emerging hydrogen technologies. The bus has been operated by the transit agency in Augusta, Georgia since April, 1997. It employs a hybrid IC engine/battery/electric drive system, with onboard hydrogen fuel storage based on the use of metal hydrides. Initial operating results have demonstrated an overall energy efficiency (miles per Btu) of twice that of a similar diesel-fueled bus and an operating range twice that of an all-battery powered electric bus. Tailpipe emissions are negligible, with NOx less than 0.2 ppm. Permitting, liability and insurance issues were addressed on the basis of extensive risk assessment and safety analyses, with the inherent safety characteristic of metal hydride storage playing a major role in minimizing these concerns. Future plans for the bus include continued transit operation and use as a national testbed, with potential modifications to demonstrate other hydrogen technologies, including fuel cells.

  5. Environmental impact assessment of bus rapid transit (BRT in the Metropolitan City of Tehran

    Directory of Open Access Journals (Sweden)

    F. Salehi

    2016-01-01

    Full Text Available Bus rapid transit is an innovative, high capacity, lower cost public transit solution in metropolitan cities. Idea is to dedicate lanes for quick and efficient transport of passengers to their destinations. In the present investigation the environmental impact assessment of bus rapid transit  in Tehran metropolitan city is brought out. For this purpose bus rapid transit Lane No. 10 is investigated. The bus rapid transit Lane No.10 is about 10 km in distance that moves up and down between Azadi and Simon Bolivar Squares. About 77500 passengers using 50 buses are transited per day in lane No. 10. These 50 buses cover a distance of 9600 km/day. The results of present study showed that about 6.5 million liters of fuel is saved annually. It should be pointed out that environmental costs are also reduced for about US$ 1.7 million/yr. The overall score of environmental impact assessment stands at +10 that is indicative of Lane No. 10 compatibility with the environmental considerations.

  6. Effects of transit bus interior configuration on performance of wheeled mobility users during simulated boarding and disembarking.

    Science.gov (United States)

    D'Souza, Clive; Paquet, Victor; Lenker, James A; Steinfeld, Edward

    2017-07-01

    The emergence of low-floor bus designs and related regulatory standards in the U.S. have resulted in substantial improvements in public transit accessibility. However, passengers using wheeled mobility devices still experience safety concerns and inefficiencies in boarding, disembarking, and interior circulation on low-floor buses. This study investigates effects of low-floor bus interior configuration and passenger crowding on boarding and disembarking efficiency and safety. Users of manual wheelchairs (n = 18), powered wheelchairs (n = 21) and electric scooters (n = 9) simulated boarding and disembarking in three interior layout configurations at low and high passenger crowding conditions on a full-scale laboratory mock-up of a low-floor bus. Dependent measures comprised task times and critical incidents during access ramp use, fare payment, and movement to and from the doorway and wheeled mobility securement area. Individual times for unassisted boarding ranged from 15.2 to 245.3 s and for disembarking ranged from 9.1 to 164.6 s across layout and passenger crowding conditions. Nonparametric analysis of variance showed significant differences and interactions across vehicle design conditions, passenger load and mobility device type on user performance. The configuration having electronic on-board fare payment, rear-bus entrance doorways and adjacent device securement areas demonstrated greatest efficiency and safety. High passenger load adversely impacted efficiency and frequency of critical incidents during on-board circulation across all three layouts. Findings have broader implications for improving transit system efficiency and quality of service across the spectrum of transit users. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Plug-in vs. wireless charging: Life cycle energy and greenhouse gas emissions for an electric bus system

    International Nuclear Information System (INIS)

    Bi, Zicheng; Song, Lingjun; De Kleine, Robert; Mi, Chunting Chris; Keoleian, Gregory A.

    2015-01-01

    Graphical abstract: In this study, plug-in and wireless charging for an all-electric bus system are compared from the life cycle energy and greenhouse gas (GHG) emissions perspectives. The comparison of life cycle GHG emissions is shown in the graph below. The major differences between the two systems, including the charger, battery and use-phase electricity consumption, are modeled separately and compared aggregately. In the base case, the wireless charging system consumes 0.3% less energy and emits 0.5% less greenhouse gases than plug-in charging system in the total life cycle. To further improve the energy and environmental performance of the wireless charging system, key parameters including grid carbon intensity and wireless charging efficiency are analyzed and discussed in this paper. - Highlights: • Compared life cycle energy and GHG emissions of wireless to plug-in charging. • Modeled a transit bus system to compare both charging methods as a case study. • Contrasted tradeoffs of infrastructure burdens with lightweighting benefits. • The wireless battery can be downsized to 27–44% of a plug-in charged battery. • Explored sensitivity of wireless charging efficiency & grid carbon intensity. - Abstract: Wireless charging, as opposed to plug-in charging, is an alternative charging method for electric vehicles (EVs) with rechargeable batteries and can be applicable to EVs with fixed routes, such as transit buses. This study adds to the current research of EV wireless charging by utilizing the Life Cycle Assessment (LCA) to provide a comprehensive framework for comparing the life cycle energy demand and greenhouse gas emissions associated with a stationary wireless charging all-electric bus system to a plug-in charging all-electric bus system. Life cycle inventory analysis of both plug-in and wireless charging hardware was conducted, and battery downsizing, vehicle lightweighting and use-phase energy consumption were modeled. A bus system in Ann Arbor

  8. Increasing throughput of multiplexed electrical bus in pipe-lined architecture

    Science.gov (United States)

    Asaad, Sameh; Brezzo, Bernard V; Kapur, Mohit

    2014-05-27

    Techniques are disclosed for increasing the throughput of a multiplexed electrical bus by exploiting available pipeline stages of a computer or other system. For example, a method for increasing a throughput of an electrical bus that connects at least two devices in a system comprises introducing at least one signal hold stage in a signal-receiving one of the two devices, such that a maximum frequency at which the two devices are operated is not limited by a number of cycles of an operating frequency of the electrical bus needed for a signal to propagate from a signal-transmitting one of the two devices to the signal-receiving one of the two devices. Preferably, the signal hold stage introduced in the signal-receiving one of the two devices is a pipeline stage re-allocated from the signal-transmitting one of the two devices.

  9. National Fuel Cell Bus Program : Accelerated Testing Report, AC Transit

    Science.gov (United States)

    2009-01-01

    This is an evaluation of hydrogen fuel cell transit buses operating at AC Transit in revenue service since March 20, 2006 compared to similar diesel buses operating from the same depot. This evaluation report includes results from November 2007 throu...

  10. Impacts of bus rapid transit (BRT) on surrounding residential property values : final report.

    Science.gov (United States)

    2017-07-01

    As bus rapid transit (BRT) grows in popularity in the United States, a better understanding of the modes impacts on land uses and property values is needed. Economic theory suggests, and literature has shown, that people are willing to pay higher ...

  11. Modeling commuter preferences for the proposed bus rapid transit in Dar-es-Salaam

    NARCIS (Netherlands)

    Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; van Maarseveen, M.F.A.M.

    2012-01-01

    The paper analyzes individual commuter preferences towards the proposed bus rapid transit (BRT) system in Dar-es-Salaam, Tanzania. The objective of the survey was to identify how commuters perceive and value the proposed BRT service quality attributes. A stated preference survey of potential users

  12. Enabling Bus Transit Service Quality Co-Monitoring Through Smartphone-Based Platform

    DEFF Research Database (Denmark)

    Li, Corinna; Zegras, P. Christopher; Zhao, Fang

    2017-01-01

    ’ word, meaning “agencies using public feedback to supplement official monitoring and regulation.”] bus service quality. The pilot project adapted a smartphone-based travel survey system, Future Mobility Sensing, to collect real-time customer feedback and objective operational measurements on specific...... monitoring through a more real-time, customer-centric perspective. The pilot project operated publicly for 3 months on the Silver Line bus rapid transit in Boston, Massachusetts. Seventy-six participants completed the entrance survey; half of them actively participated and completed more than 500...

  13. Ultra-Capacitor Energy Storage in a Large Hybrid Electric Bus

    Science.gov (United States)

    Viterna, L. A.

    1997-01-01

    The power requirements for inner city transit buses are characterized by power peaks about an order of magnitude larger than the average power usage of the vehicle. For these vehicles, hybrid power trains can offer significantly improved fuel economy and exhaust emissions. A critical design challenge, however, has been developing the energy storage and power management system to respond to these rapid power variations. Most hybrid vehicles today use chemical energy storage batteries to supplement the power from the fuel burning generator unit. Chemical storage batteries however, present several difficulties in power management and control. These difficulties include (1) inadequate life, (2) limited current delivery as well as absorption during regenerative braking, (3) inaccurate measurement of state of charge, and (4) stored energy safety issues. Recent advances in ultra-capacitor technology create an opportunity to address these concerns. The NASA Lewis Research Center, in cooperation with industry and academia, has developed an advanced hybrid electric transit bus using ultra-capacitors as the primary energy storage system. At over 15,000-kg gross weight, this is the largest vehicle of its kind ever built using this advanced energy storage technology. Results of analyses show that the vehicle will match the performance of an equivalent conventionally powered vehicle over typical inner city drive cycles. This paper describes the overall power system architecture, the evolution of the control strategy, and analysis of power flow and vehicle performance.

  14. Design of belt conveyor electric control device based on CC-link bus

    Science.gov (United States)

    Chen, Goufen; Zhan, Minhua; Li, Jiehua

    2016-01-01

    In view of problem of the existing coal mine belt conveyor is no field bus communication function, two levels belt conveyor electric control system design is proposed based on field bus. Two-stage belt conveyor electric control system consists of operation platform, PLC control unit, various sensors, alarm device and the water spraying device. The error protection is realized by PLC programming, made use of CC-Link bus technology, the data share and the cooperative control came true between host station and slave station. The real-time monitor was achieved by the touch screen program. Practical application shows that the system can ensure the coalmine production, and improve the automatic level of the coalmine transport equipment.

  15. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  16. Braking energy regeneration control of a fuel cell hybrid electric bus

    International Nuclear Information System (INIS)

    Zhang, Junzhi; Lv, Chen; Qiu, Mingzhe; Li, Yutong; Sun, Dongsheng

    2013-01-01

    Highlights: • A braking energy regeneration system has been designed for a fuel cell bus. • Control strategy coordinating energy efficiency and brake safety is proposed. • The system and control strategy proposed are experimentally verified. • Based on test results, energy efficiency of the FCB is improved greatly. - Abstract: This paper presents the braking energy regeneration control of a fuel cell hybrid electric bus. The configuration of the regenerative braking system based on a pneumatic braking system was proposed. To recapture the braking energy and improve the fuel economy, a control strategy coordinating the regenerative brake and the pneumatic brake was designed and applied in the FCHB. Brake safety was also guaranteed by the control strategy when the bus encounters critical driving situations. Fuel economy tests were carried out under China city bus typical driving cycle. And hardware-in-the-loop tests of the brake safety of the FCHB under proposed control strategy were also accomplished. Test results indicate that the present approach provides an improvement in fuel economy of the fuel cell hybrid electric bus and guarantees the brake safety in the meantime

  17. Hydrogen and Fuel Cell Transit Bus Evaluations : Joint Evaluation Plan for the U.S. Department of Energy and the Federal Transit Administration

    Science.gov (United States)

    2008-05-01

    This document describes the hydrogen transit bus evaluations performed by the National Renewable Energy Laboratory (NREL) and funded by the U.S. Department of Energy (DOE) and the U.S. Department of Transportations Federal Transit Administration (...

  18. Ramp-related incidents involving wheeled mobility device users during transit bus boarding/alighting.

    Science.gov (United States)

    Frost, Karen L; Bertocci, Gina; Smalley, Craig

    2015-05-01

    To estimate the prevalence of wheeled mobility device (WhMD) ramp-related incidents while boarding/alighting a public transit bus and to determine whether the frequency of incidents is less when the ramp slope meets the proposed Americans with Disabilities Act (ADA) maximum allowable limit of ≤9.5°. Observational study. Community public transportation. WhMD users (N=414) accessing a public transit bus equipped with an instrumented ramp. Not applicable. Prevalence of boarding/alighting incidents involving WhMD users and associated ramp slopes; factors affecting incidents. A total of 4.6% (n=35) of WhMD users experienced an incident while boarding/alighting a transit bus. Significantly more incidents occurred during boarding (6.3%, n=26) than during alighting (2.2%, n=9) (Pboard/alight when the ramp slope exceeded the proposed ADA maximum allowable ramp slope was 5.1 (95% confidence interval, 2.9-9.0; P9.5° and ramps deployed to street level are associated with a higher frequency of incidents and provision of assistance. Transit agencies should increase awareness among bus operators of the effect kneeling and deployment location (street/sidewalk) have on the ramp slope. In addition, ramp components and the built environment may contribute to incidents. When prescribing WhMDs, skills training must include ascending/descending ramps at slopes encountered during boarding/alighting to ensure safe and independent access to public transit buses. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. A Feeder-Bus Dispatch Planning Model for Emergency Evacuation in Urban Rail Transit Corridors

    Science.gov (United States)

    Wang, Yun; Yan, Xuedong; Zhou, Yu; Zhang, Wenyi

    2016-01-01

    The mobility of modern metropolises strongly relies on urban rail transit (URT) systems, and such a heavy dependence causes that even minor service interruptions would make the URT systems unsustainable. This study aims at optimally dispatching the ground feeder-bus to coordinate with the urban rails’ operation for eliminating the effect of unexpected service interruptions in URT corridors. A feeder-bus dispatch planning model was proposed for the collaborative optimization of URT and feeder-bus cooperation under emergency situations and minimizing the total evacuation cost of the feeder-buses. To solve the model, a concept of dummy feeder-bus system is proposed to transform the non-linear model into traditional linear programming (ILP) model, i.e., traditional transportation problem. The case study of Line #2 of Nanjing URT in China was adopted to illustrate the model application and sensitivity analyses of the key variables. The modeling results show that as the evacuation time window increases, the total evacuation cost as well as the number of dispatched feeder-buses decrease, and the dispatched feeder-buses need operate for more times along the feeder-bus line. The number of dispatched feeder-buses does not show an obvious change with the increase of parking spot capacity and time window, indicating that simply increasing the parking spot capacity would cause huge waste for the emergent bus utilization. When the unbalanced evacuation demand exists between stations, the more feeder-buses are needed. The method of this study will contribute to improving transportation emergency management and resource allocation for URT systems. PMID:27676179

  20. Thermo-electric analysis of the interconnection of the LHC main superconducting bus bars

    Science.gov (United States)

    Granieri, P. P.; Breschi, M.; Casali, M.; Bottura, L.; Siemko, A.

    2013-01-01

    Spurred by the question of the maximum allowable energy for the operation of the Large Hadron Collider (LHC), we have progressed in the understanding of the thermo-electric behavior of the 13 kA superconducting bus bars interconnecting its main magnets. A deep insight of the underlying mechanisms is required to ensure the protection of the accelerator against undesired effects of resistive transitions. This is especially important in case of defective interconnections which can jeopardize the operation of the whole LHC. In this paper we present a numerical model of the interconnections between the main dipole and quadrupole magnets, validated against experimental tests of an interconnection sample with a purposely built-in defect. We consider defective interconnections featuring a lack of bonding among the superconducting cables and the copper stabilizer components, such as those that could be present in the machine. We evaluate the critical defect length limiting the maximum allowable current for powering the magnets. We determine the dependence of the critical defect length on different parameters as the heat transfer towards the cooling helium bath, the quality of manufacturing, the operating conditions and the protection system parameters, and discuss the relevant mechanisms.

  1. Analysis, operation and maintenance of a fuel cell/battery series-hybrid bus for urban transit applications

    Energy Technology Data Exchange (ETDEWEB)

    Bubna, Piyush; Brunner, Doug; Gangloff, John J. Jr.; Advani, Suresh G.; Prasad, Ajay K. (Center for Fuel Cell Research, Department of Mechanical Engineering, University of Delaware, Newark, DE 19716 United States)

    2010-06-15

    The fuel cell hybrid bus (FCHB) program was initiated at the University of Delaware in 2005 to demonstrate the viability of fuel cell vehicles for transit applications and to conduct research and development to facilitate the path towards their eventual commercialization. Unlike other fuel cell bus programs, the University of Delaware's FCHB design features a battery-heavy hybrid which offers multiple advantages in terms of cost, performance and durability. The current fuel cell hybrid bus is driven on a regular transit route at the University of Delaware. The paper describes the baseline specifications of the bus with a focus on the fuel cell and the balance of plant. The fuel cell/battery series-hybrid design is well suited for urban transit routes and provides key operational advantages such as hydrogen fuel economy, efficient use of the fuel cell for battery recharging, and regenerative braking. The bus is equipped with a variety of sensors including a custom-designed cell voltage monitoring system which provide a good understanding of bus performance under normal operation. Real-time data collection and analysis have yielded key insights for fuel cell bus design optimization. Results presented here illustrate the complex flow of energy within the various subsystems of the fuel cell hybrid bus. A description of maintenance events has been included to highlight the issues that arise during general operation. The paper also describes several modifications that will facilitate design improvements in future versions of the bus. Overall, the fuel cell hybrid bus demonstrates the viability of fuel cells for urban transit applications in real world conditions. (author)

  2. Analysis, operation and maintenance of a fuel cell/battery series-hybrid bus for urban transit applications

    Science.gov (United States)

    Bubna, Piyush; Brunner, Doug; Gangloff, John J.; Advani, Suresh G.; Prasad, Ajay K.

    The fuel cell hybrid bus (FCHB) program was initiated at the University of Delaware in 2005 to demonstrate the viability of fuel cell vehicles for transit applications and to conduct research and development to facilitate the path towards their eventual commercialization. Unlike other fuel cell bus programs, the University of Delaware's FCHB design features a battery-heavy hybrid which offers multiple advantages in terms of cost, performance and durability. The current fuel cell hybrid bus is driven on a regular transit route at the University of Delaware. The paper describes the baseline specifications of the bus with a focus on the fuel cell and the balance of plant. The fuel cell/battery series-hybrid design is well suited for urban transit routes and provides key operational advantages such as hydrogen fuel economy, efficient use of the fuel cell for battery recharging, and regenerative braking. The bus is equipped with a variety of sensors including a custom-designed cell voltage monitoring system which provide a good understanding of bus performance under normal operation. Real-time data collection and analysis have yielded key insights for fuel cell bus design optimization. Results presented here illustrate the complex flow of energy within the various subsystems of the fuel cell hybrid bus. A description of maintenance events has been included to highlight the issues that arise during general operation. The paper also describes several modifications that will facilitate design improvements in future versions of the bus. Overall, the fuel cell hybrid bus demonstrates the viability of fuel cells for urban transit applications in real world conditions.

  3. Simulating Study on Drive System Performance for Hybrid Electric Bus Based on ADVISOR

    Directory of Open Access Journals (Sweden)

    Wang Xingxing

    2017-01-01

    Full Text Available Hybrid electric bus has a number of advantages when compared with ordinary passenger cars, but in the dynamic matching and the vehicle performance are difficult to detect, thus limits its development process. In this paper, combined with the actual models, the hybrid electric bus module parameters were modified in the software of ADVISOR (Advanced Vehicle Simulator, main including: module of the vehicle, the wheel module, motor module, a battery module and engine module, three kinds of bus models for A, B and C were established, and the related performance that need to be analyzed was set up, such as acceleration, gradability, emissions and energy utilization and so on, in order to ensure the vehicle running in the same environment and convenient for comparison, a fixed vehicle driving cycles was chose, then the simulation results was analyzed, and the various performance was compared with the dynamic indicators and economic indicators which determined by referencing of traditional city bus standard and each other, and finally, the performance optimal model of B was chose out which can meet the demand, its related performance parameters of the simulation results are as follows: the best gradability is 26%, maximum speed is 72.7km/h, maximum acceleration is 1.7m/s2, 0~50km/h acceleration time is 9.5s and fuel consumption is 25L/km.

  4. Compressed Natural Gas (CNG) Transit Bus Experience Survey: April 2009--April 2010

    Energy Technology Data Exchange (ETDEWEB)

    Adams, R.; Horne, D. B.

    2010-09-01

    This survey was commissioned by the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) to collect and analyze experiential data and information from a cross-section of U.S. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience. This information will be used to assist DOE and NREL in determining areas of success and areas where further technical or other assistance might be required, and to assist them in focusing on areas judged by the CNG transit community as priority items.

  5. Transit experience with hydrogen fueled hybrid electric buses

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.B.; Mazaika, D.M. [ISE Corp., Poway, CA (United States)

    2006-07-01

    Mass transit buses are ideal candidates for hydrogen implementation due to their capability of carrying 30 to 60 kg of hydrogen. ISE Corporation is a supplier of hydrogen fueled buses, including the first hybrid electric fuel cell bus which was commercialized in 2002, the hybrid electric fuel cell bus, and the hybrid hydrogen internal combustion engine (HHICE) bus which was commercialized in 2004. The configuration of a HHICE bus was illustrated with reference to its engine, control system, energy storage, generator, drive motor, inverter and accessories. Although these vehicles are expensive, the cost is amortized over a large base of hours used and passengers carried. The buses are operated primarily in urban areas where quiet and clean operation is needed the most. ISE has established a joint venture with Thor industries to develop a series of fuel cell buses equipped with a 60 kW PEM fuel cell. A schematic illustrating the energy flow in HHICE bus was also presented. It was shown that regenerative braking recovers the energy of motion. When using regenerative braking, most of the braking energy is saved in the battery. ISE drive systems convert 30 per cent or more of the bus energy to electrical energy to be used in later acceleration. Reduced fuel consumption also reduces the vehicle emissions. Testing of HHICE buses in both summer and winter operating conditions have shown that the range needs to be improved along with engine component reliability and durability. Fuel supply is also a major issue. A comparison with a fuel cell hybrid system was also presented. In the United States, more than 100,000 miles have been logged for the use of hydrogen hybrid buses, fuel cell buses and HHICE buses. The HHICE bus offers low capital cost, familiar technologies, but some NOx. CAT absorber technology offers the possibility of near zero emission capability. The fuel cell bus was found to be more fuel efficient, and can travel nearly twice as far per unit energy as

  6. Operational demands as determining factor for electric bus charging infrastructure

    NARCIS (Netherlands)

    Beekman, R.; Van Den Hoed, R.

    2016-01-01

    Many cities in Europe have ambitious goals when it comes to making their public transport buses emission free. This article outlines the reasoning behind the choices made in the city of Amsterdam with regards to charging infrastructure for electric buses. Emphasising the importance of operational

  7. Frame analysis of UNNES electric bus chassis construction using finite element method

    Science.gov (United States)

    Nugroho, Untoro; Anis, Samsudin; Kusumawardani, Rini; Khoiron, Ahmad Mustamil; Maulana, Syahdan Sigit; Irvandi, Muhammad; Mashdiq, Zia Putra

    2018-03-01

    Designing the chassis needs to be done element simulation analysis to gain chassis strength on an electric bus. The purpose of this research is to get the results of chassis simulation on an electric bus when having load use FEM (Finite element method). This research was conduct in several stages of process, such as modeling chassis by Autodesk Inventor and finite element simulation software. The frame is going to be simulated with static loading by determine fixed support and then will be given the vertical force. The fixed on the frame is clamped at both the front and rear suspensions. After the simulation based on FEM it can conclude that frame is still under elastic zone, until the frame design is safe to use.

  8. Optimizing Performance of at-grade Intersection with Bus Rapid Transit Corridor and Heterogeneous Traffic

    Directory of Open Access Journals (Sweden)

    Hemant Kumar Sharma

    2012-06-01

    Full Text Available Bus Rapid Transit (BRT has emerged as a preferred mode of public transport in various countries all over the world for its cost effectiveness in construction as well as in operation and maintenance. The rapid transit feature of BRT is seen as a solution to many traffic problems in these countries. However, in developing countries like India, the right -of-way for most of the roads is restricted and traffic is heterogeneous in nature. Provision of BRT in existing right -of-way reduces the capacity available for other motorized traffic. As the buses travel with a certain frequency on dedicated bus- ways, the dedicated corridor remains unused for most of the period when other traffic on motorized vehicle (MV lanes suffers from congestion. The problem gets severe at intersections. However, if buses are operated in mixed traffic it is no more rapid transit. Hence, a solution is required to address this problem and optimize the performance of traffic as a whole. This paper presents the effect if dedicated bus-ways end at a reasonable distance before the stop line at a busy signalized at-grade intersection, and bus lanes (beyond that are made available to all the motorized vehicular traffic (heterogeneous traffic at intersection. The performance evaluation is done in terms of average queue length, maximum queue length, average delay time per vehicle, vehicle throughput, average speed in network and emission of Carbon monoxide CO, mono-nitrogen oxides NOx and Volatile organic compounds (VOC. It is observed that availability of bus lanes to other motorized traffic for a reasonable distance before intersection considerably reduces the average queue length, maximum queue length, average delay time per vehicle and emission per vehicle, while there is an increase in vehicle throughput and average speed of all the vehicles in the network. Thus it results in reduction of congestion and performance enhancement of at-grade intersections and network. Results of

  9. Relationships of working conditions, health problems and vehicle accidents in bus rapid transit (BRT) drivers.

    Science.gov (United States)

    Gómez-Ortiz, Viviola; Cendales, Boris; Useche, Sergio; Bocarejo, Juan P

    2018-04-01

    The aim of this study was to estimate accident risk rates and mental health of bus rapid transit (BRT) drivers based on psychosocial risk factors at work leading to increased stress and health problems. A cross-sectional research design utilized a self-report questionnaire completed by 524 BRT drivers. Some working conditions of BRT drivers (lack of social support from supervisors and perceived potential for risk) may partially explain Bogota's BRT drivers' involvement in road accidents. Drivers' mental health problems were associated with higher job strain, less support from co-workers, fewer rewards and greater signal conflict while driving. To prevent bus accidents, supervisory support may need to be increased. To prevent mental health problems, other interventions may be needed such as reducing demands, increasing job control, reducing amount of incoming information, simplifying current signals, making signals less contradictory, and revising rewards. © 2018 Wiley Periodicals, Inc.

  10. Implementation of Bus Rapid Transit in Copenhagen: A Mesoscopic Model Approach

    DEFF Research Database (Denmark)

    Ingvardson, Jesper Bláfoss; Kornerup Jensen, Jonas

    2012-01-01

    Bus Rapid Transit(BRT) has shown to be an efficient and cost-effective mode of public transport, and has gained popularity in many cities around the world.To optimise the operations and infrastructure it is advantageous to deploy transportmodels. However, microscopic models are very inefficient...... upgrades (busways and enhanced stations) ensure a reduction to traveltime whereas no improvements to reliability occur. Upgrades to technology and serviceplanning (pre-paid fare collection, boarding and alighting from all doors, special BRT vehicles, ITS, and active bus control) ensure an increase...... in service reliability whereas only small reductions to travel time are observed. By combining all BRT elements it is possible to obtain synergies where the improved reliability due to planning and technology elements makes it possible to utilise the infrastructure optimally. Hence, it is possible...

  11. Assessment of alternative fuel and powertrain transit bus options using real-world operations data: Life-cycle fuel and emissions modeling

    International Nuclear Information System (INIS)

    Xu, Yanzhi; Gbologah, Franklin E.; Lee, Dong-Yeon; Liu, Haobing; Rodgers, Michael O.; Guensler, Randall L.

    2015-01-01

    Highlights: • We present a practical fuel and emissions modeling tool for alternative fuel buses. • The model assesses well-to-wheels emissions impacts of bus fleet decisions. • Mode-based approach is used to account for duty cycles and local conditions. • A case study using real-world operations data from Atlanta, GA is presented. • Impacts of alternative bus options depend on operating and geographic features. - Abstract: Hybrid and electric powertrains and alternative fuels (e.g., compressed natural gas (CNG), biodiesel, or hydrogen) can often reduce energy consumption and emissions from transit bus operations relative to conventional diesel. However, the magnitude of these energy and emissions savings can vary significantly, due to local conditions and transit operating characteristics. This paper introduces the transit Fuel and Emissions Calculator (FEC), a mode-based life-cycle emissions modeling tool for transit bus and rail technologies that compares the performance of multiple alternative fuels and powertrains across a range of operational characteristics and conditions. The purpose of the FEC is to provide a practical, yet technically sophisticated tool for regulatory agencies and policy analysts in assessing transit fleet options. The FEC’s modal modeling approach estimates emissions as a function of engine load, which in turn is a function of transit service parameters, including duty cycle (idling and speed-acceleration profile), road grade, and passenger loading. This approach allows for customized assessments that account for local conditions. Direct emissions estimates are derived from the scaled tractive power (STP) operating mode bins and emissions factors employed in the U.S. EPA’s MOVES (MOtor Vehicle Emissions Simulator) model. Life-cycle emissions estimates are calculated using emissions factors from the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model. The case study presented in this paper

  12. Advanced Intelligent System Application to Load Forecasting and Control for Hybrid Electric Bus

    Science.gov (United States)

    Momoh, James; Chattopadhyay, Deb; Elfayoumy, Mahmoud

    1996-01-01

    The primary motivation for this research emanates from providing a decision support system to the electric bus operators in the municipal and urban localities which will guide the operators to maintain an optimal compromise among the noise level, pollution level, fuel usage etc. This study is backed up by our previous studies on study of battery characteristics, permanent magnet DC motor studies and electric traction motor size studies completed in the first year. The operator of the Hybrid Electric Car must determine optimal power management schedule to meet a given load demand for different weather and road conditions. The decision support system for the bus operator comprises three sub-tasks viz. forecast of the electrical load for the route to be traversed divided into specified time periods (few minutes); deriving an optimal 'plan' or 'preschedule' based on the load forecast for the entire time-horizon (i.e., for all time periods) ahead of time; and finally employing corrective control action to monitor and modify the optimal plan in real-time. A fully connected artificial neural network (ANN) model is developed for forecasting the kW requirement for hybrid electric bus based on inputs like climatic conditions, passenger load, road inclination, etc. The ANN model is trained using back-propagation algorithm employing improved optimization techniques like projected Lagrangian technique. The pre-scheduler is based on a Goal-Programming (GP) optimization model with noise, pollution and fuel usage as the three objectives. GP has the capability of analyzing the trade-off among the conflicting objectives and arriving at the optimal activity levels, e.g., throttle settings. The corrective control action or the third sub-task is formulated as an optimal control model with inputs from the real-time data base as well as the GP model to minimize the error (or deviation) from the optimal plan. These three activities linked with the ANN forecaster proving the output to the

  13. Power-balancing instantaneous optimization energy management for a novel series-parallel hybrid electric bus

    Science.gov (United States)

    Sun, Dongye; Lin, Xinyou; Qin, Datong; Deng, Tao

    2012-11-01

    Energy management(EM) is a core technique of hybrid electric bus(HEB) in order to advance fuel economy performance optimization and is unique for the corresponding configuration. There are existing algorithms of control strategy seldom take battery power management into account with international combustion engine power management. In this paper, a type of power-balancing instantaneous optimization(PBIO) energy management control strategy is proposed for a novel series-parallel hybrid electric bus. According to the characteristic of the novel series-parallel architecture, the switching boundary condition between series and parallel mode as well as the control rules of the power-balancing strategy are developed. The equivalent fuel model of battery is implemented and combined with the fuel of engine to constitute the objective function which is to minimize the fuel consumption at each sampled time and to coordinate the power distribution in real-time between the engine and battery. To validate the proposed strategy effective and reasonable, a forward model is built based on Matlab/Simulink for the simulation and the dSPACE autobox is applied to act as a controller for hardware in-the-loop integrated with bench test. Both the results of simulation and hardware-in-the-loop demonstrate that the proposed strategy not only enable to sustain the battery SOC within its operational range and keep the engine operation point locating the peak efficiency region, but also the fuel economy of series-parallel hybrid electric bus(SPHEB) dramatically advanced up to 30.73% via comparing with the prototype bus and a similar improvement for PBIO strategy relative to rule-based strategy, the reduction of fuel consumption is up to 12.38%. The proposed research ensures the algorithm of PBIO is real-time applicability, improves the efficiency of SPHEB system, as well as suite to complicated configuration perfectly.

  14. Morphology of single inhalable particle inside public transit biodiesel fueled bus.

    Science.gov (United States)

    Shandilya, Kaushik K; Kumar, Ashok

    2010-01-01

    In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry (SEM/EDS). Particle size analysis found bimodal distribution at 0.2 and 0.5 microm. The particle morphology was characterized by 14 different shape clusters: square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick, and unknown, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or sticks are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.

  15. Analysis of On-Board Photovoltaics for a Battery Electric Bus and Their Impact on Battery Lifespan

    Directory of Open Access Journals (Sweden)

    Kevin R. Mallon

    2017-07-01

    Full Text Available Heavy-duty electric powertrains provide a potential solution to the high emissions and low fuel economy of trucks, buses, and other heavy-duty vehicles. However, the cost, weight, and lifespan of electric vehicle batteries limit the implementation of such vehicles. This paper proposes supplementing the battery with on-board photovoltaic modules. In this paper, a bus model is created to analyze the impact of on-board photovoltaics on electric bus range and battery lifespan. Photovoltaic systems that cover the bus roof and bus sides are considered. The bus model is simulated on a suburban bus drive cycle on a bus route in Davis, CA, USA for a representative sample of yearly weather conditions. Roof-mounted panels increased vehicle driving range by 4.7% on average annually, while roof and side modules together increased driving range by 8.9%. However, variations in weather conditions meant that this additional range was not reliably available. For constant vehicle range, rooftop photovoltaic modules extended battery cycle life by up to 10% while modules on both the roof and sides extended battery cycle life by up to 19%. Although side-mounted photovoltaics increased cycle life and range, they were less weight- and cost-effective compared to the roof-mounted panels.

  16. Microbial air quality in mass transport buses and work-related illness among bus drivers of Bangkok Mass Transit Authority.

    Science.gov (United States)

    Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

    2004-06-01

    The air quality in mass transport buses, especially air-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok Mass Transit Authority were randomly selected to investigate for microbial air quality. Nine air-conditioned buses and 2-4 open-air buses for each number of the bus (36 air-conditioned buses and 12 open-air buses) were included. Five points of in-bus air samples in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 air samples collected from air-conditioned buses and open-air buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results revealed that the mean +/- SD of bacterial counts in the studied open-air buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied air-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied air samples were analyzed in detail, it was found that 33.33% of the air samples from open-air buses and 6.11% of air samples from air-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of air samples from open-air buses and 2.78% of air samples from air-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-air bus drivers and 57.28% of air-conditioned bus drivers had

  17. Intelligent Bus Stops in the Flexible Bus Systems

    OpenAIRE

    Razi Iqbal; Muhammad Usman Ghani

    2014-01-01

    The purpose of this paper is to discuss Intelligent Bus Stops in a special Demand Responsive Transit (DRT), the Flexible Bus System. These Intelligent Bus Stops are more efficient and information rich than Traditional Bus Stops. The real time synchronization of the Flexible Bus System makes it unique as compared to Traditional Bus Systems. The Main concern is to make Bus Stops intelligent and information rich. Buses are informed about the no. of passengers waiting at the upcoming ...

  18. Electrical engineering unit for the reactive power control of the load bus at the voltage instability

    Science.gov (United States)

    Kotenev, A. V.; Kotenev, V. I.; Kochetkov, V. V.; Elkin, D. A.

    2018-01-01

    For the purpose of reactive power control error reduction and decrease of the voltage sags in the electric power system caused by the asynchronous motors started the mathematical model of the load bus was developed. The model was built up of the sub-models of the following elements: a transformer, a transmission line, a synchronous and an asynchronous loads and a capacitor bank load, and represents the automatic reactive power control system taking into account electromagnetic processes of the asynchronous motors started and reactive power changing of the electric power system elements caused by the voltage fluctuation. The active power/time and reactive power/time characteristics based on the recommended procedure of the equivalent electric circuit parameters calculation were obtained. The derived automatic reactive power control system was shown to eliminate the voltage sags in the electric power system caused by the asynchronous motors started.

  19. Electrical Conductivity in Transition Metals

    Science.gov (United States)

    Talbot, Christopher; Vickneson, Kishanda

    2013-01-01

    The aim of this "Science Note" is to describe how to test the electron-sea model to determine whether it accurately predicts relative electrical conductivity for first-row transition metals. In the electron-sea model, a metal crystal is viewed as a three-dimensional array of metal cations immersed in a sea of delocalised valence…

  20. Preferensi Konsumen Terhadap Transportasi Publik (Studi Kasus Bus Rapid Transit (BRT Kota Semarang

    Directory of Open Access Journals (Sweden)

    Ichwinsyah Azali

    2018-01-01

    Abstract Semarang as the capital city of Central Java Province has a population density of 4.269 per square kilometer in 2015. Due to high population density, communities’ mobility will also be increasing. Government arranged the policy related to traffic and public transportation in the Law Number 22 Year 2009 article 158 paragraph 1, the government of Semarang City has guaranteed the availability of road-based transportation in Urban Areas by providing public transportation namely Bus Rapid Transit (BRT Trans Semarang. This research aims to analyze communities’ preference in terms of price, convenience, reliability, accessibility, and safety toward the possibility of BRT and Non BRT transportation modes selection. This research uses 100 respondents by Purposive Sampling. Binary Logistic Regression model is applied to determine the effect of independent variable towards dependent variable of BRT and Non BRT transportation modes selection. The result of this research indicated that BRT and Non BRT transportation modes selection in Semarang City are dominated by 82 respondents of BRT users and 18 respondents of Non BRT users. BRT and Non BRT transportation modes selection are affected by the factor of price, convenience, reliability, accessibility, and safety. Keywords: Modes selection, Bus Rapid Transit (BRT Trans Semarang, Principal Component Analysis, Binary Logistic Regression.

  1. GO Bus impact analysis.

    Science.gov (United States)

    2013-08-01

    NJ TRANSIT launched two relatively new enhanced bus services: GO 25 serving the : Springfield Avenue corridor in 2008 and GO 28 serving the Bloomfield Avenue corridor in 2009. : As an enhanced but not full Bus Rapid Transit (BRT) service, GO Bus feat...

  2. CRADA Final Report for CRADA Number ORNL98-0521 : Development of an Electric Bus Inverter Based on ORNL Auxiliary Resonant Tank (ART) Soft-Switching Technology; TOPICAL

    International Nuclear Information System (INIS)

    Ayers, C.W.

    2001-01-01

    The Power Electronics and Electric Machinery Research Center (PEEMRC) of Oak Ridge National Laboratory (ORNL) has for many years been developing technologies for power converters for motor drives and many other applications. Some of the research goals are to improve efficiency and reduce audible and electromagnetic interference noise generation for inverters and the driven loads. The converters are being required to produce more power with reduced weight and volume, which requires improvements in heat removal from the electronics, as well as improved circuit designs that have fewer electrical losses. PEEMRC has recently developed and patented a soft-switching inverter topology called an Auxiliary Resonant Tank (ART), and this design has been tested and proven at ORNL using a 10-kW laboratory prototype. The objective of this project was to develop, test, and install the ART inverter technology in an electric transit bus with the final goal of evaluating performance of the ORNL inverter under field conditions in a vehicle. A scaled-up inverter with the capacity to drive a 22-e bus was built based on the 10-kW ORNL laboratory prototype ART soft-switching inverter. Most (if not all) commercially available inverters for traction drive and other applications use hard-switching inverters. A Cooperative Research and Development Agreement was established with the Chattanooga Area Regional Transit Authority (CARTA), the Electric Transit Vehicle Institute (ETVI), and Advanced Vehicle Systems (AVS), all of Chattanooga, along with ORNL. CARTA, which maintains and operates the public transit system in Chattanooga, provided an area for testing the vehicle alongside other similar vehicles in the normal operating environment. ETVI offers capabilities in standardized testing and reporting and also provides exposure in the electric transit vehicle arena for ORNL's technologies. The third Chattanooga partner, (AVS) manufactures all-electric and hybrid electric transit buses using

  3. Very-low-frequency and low-frequency electric and magnetic fields associated with electric shuttle bus wireless charging

    International Nuclear Information System (INIS)

    Tell, R. A.; Kavet, R.; Bailey, J. R.; Halliwell, J.

    2014-01-01

    Tests conducted to date at the University of Tennessee at Chattanooga (UTC) indicate that wireless charging of the Chattanooga Area Regional Transportation Authority's (CARTA) downtown shuttle bus, currently operating with off-board battery charging technology, offers significant improvements in performance and cost. The system operates at a frequency of 20 kHz and a peak power of 60 kW. Because the system's wireless charging is expected to occur during a nominal 3-min charging period with passengers on-board, the magnetic and electric fields associated with charging were characterised at UTC's Advanced Vehicle Test Facility and compared with established human exposure limits. The two most prominent exposure limits are those published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute for Electrical and Electronic Engineers (IEEE). Both organisations include limits for groups who are trained (workers in specific industries) to be aware of electromagnetic environments and their potential hazards, as well as a lower set of limits for the general public, who are assumed to lack such awareness. None of the magnetic or electric fields measured either within or outside the bus during charging exceeded either the ICNIRP or the IEEE exposure limits for the general public. (authors)

  4. Developing a Natural Gas-Powered Bus Rapid Transit Service: A Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.

    2015-11-03

    The Roaring Fork Transit Authority (RFTA) and its VelociRFTA Bus Rapid Transit (BRT) program are unique in many ways. For example, VelociRFTA was the first rural BRT system in the United States and the operational environment of the VelociRFTA BRT is one of the most severe in the country, with extreme winter temperatures and altitudes close to 8,000 feet. RFTA viewed high altitude operation as the most challenging characteristic when it began considering the use of natural gas. RFTA is the second-largest public transit system in Colorado behind Denver's Regional Transportation District (RTD), and it is one of the largest rural public transit systems in the country. In 2013, RFTA accepted delivery of 22 new compressed natural gas (CNG) buses that went into service after completion of maintenance and refueling facilities earlier that year. This paper examines the lessons learned from RFTA's experience of investigating--and ultimately choosing--CNG for their new BRT program and focuses on the unique environment of RFTA's BRT application; the decision process to include CNG fueling in the project; unforeseen difficulties encountered in the operation of CNG buses; public perception; cost comparison to competing fuels; and considerations for indoor fueling facilities and project funding.

  5. Developing a Natural Gas-Powered Bus Rapid Transit Service. A Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, George [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-01

    The Roaring Fork Transit Authority (RFTA) and its VelociRFTA Bus Rapid Transit (BRT) program are unique in many ways. For example, VelociRFTA was the first rural BRT system in the United States and the operational environment of the VelociRFTA BRT is one of the most severe in the country, with extreme winter temperatures and altitudes close to 8,000 feet. RFTA viewed high altitude operation as the most challenging characteristic when it began considering the use of natural gas. RFTA is the second-largest public transit system in Colorado behind Denver's Regional Transportation District (RTD), and it is one of the largest rural public transit systems in the country. In 2013, RFTA accepted delivery of 22 new compressed natural gas (CNG) buses that went into service after completion of maintenance and refueling facilities earlier that year. This paper examines the lessons learned from RFTA's experience of investigating--and ultimately choosing--CNG for their new BRT program and focuses on the unique environment of RFTA's BRT application; the decision process to include CNG fueling in the project; unforeseen difficulties encountered in the operation of CNG buses; public perception; cost comparison to competing fuels; and considerations for indoor fueling facilities and project funding.

  6. Modeling the Equilibrium Bus Line Choice Behavior and Transit System Design with Oblivious Users

    Directory of Open Access Journals (Sweden)

    Chuan-Lin Zhao

    2014-01-01

    Full Text Available In most of transportation literature, users are assumed to be perfectly rational in minimizing their own travel costs or perceived travel costs. However, users may not be perfectly rational in implementing their choices in reality. There exists a kind of boundedly rational users, that is, oblivious users. These oblivious users make their route choices by simple criteria, for example, selecting the shortest (or the most direct route only based on physical distance or simply following routes recommended by a GPS system. This paper investigates how the existence of oblivious users affects the equilibrium bus line choice behavior in a public transit system. And we propose a method to design a more realistic system.

  7. Trip-oriented stochastic optimal energy management strategy for plug-in hybrid electric bus

    International Nuclear Information System (INIS)

    Du, Yongchang; Zhao, Yue; Wang, Qinpu; Zhang, Yuanbo; Xia, Huaicheng

    2016-01-01

    A trip-oriented stochastic optimal energy management strategy for plug-in hybrid electric bus is presented in this paper, which includes the offline stochastic dynamic programming part and the online implementation part performed by equivalent consumption minimization strategy. In the offline part, historical driving cycles of the fixed route are divided into segments according to the position of bus stops, and then a segment-based stochastic driving condition model based on Markov chain is built. With the segment-based stochastic model obtained, the control set for real-time implemented equivalent consumption minimization strategy can be achieved by solving the offline stochastic dynamic programming problem. Results of stochastic dynamic programming are converted into a 3-dimensional lookup table of parameters for online implemented equivalent consumption minimization strategy. The proposed strategy is verified by both simulation and hardware-in-loop test of real-world driving cycle on an urban bus route. Simulation results show that the proposed method outperforms both the well-tuned equivalent consumption minimization strategy and the rule-based strategy in terms of fuel economy, and even proved to be close to the optimal result obtained by dynamic programming. Furthermore, the practical application potential of the proposed control method was proved by hardware-in-loop test. - Highlights: • A stochastic problem was formed based on a stochastic segment-based driving condition model. • Offline stochastic dynamic programming was employed to solve the stochastic problem. • The instant power split decision was made by the online equivalent consumption minimization strategy. • Good performance in fuel economy of the proposed method was verified by simulation results. • Practical application potential of the proposed method was verified by the hardware-in-loop test results.

  8. Parameters Design for a Parallel Hybrid Electric Bus Using Regenerative Brake Model

    Directory of Open Access Journals (Sweden)

    Zilin Ma

    2014-01-01

    Full Text Available A design methodology which uses the regenerative brake model is introduced to determine the major system parameters of a parallel electric hybrid bus drive train. Hybrid system parameters mainly include the power rating of internal combustion engine (ICE, gear ratios of transmission, power rating, and maximal torque of motor, power, and capacity of battery. The regenerative model is built in the vehicle model to estimate the regenerative energy in the real road conditions. The design target is to ensure that the vehicle meets the specified vehicle performance, such as speed and acceleration, and at the same time, operates the ICE within an expected speed range. Several pairs of parameters are selected from the result analysis, and the fuel saving result in the road test shows that a 25% reduction is achieved in fuel consumption.

  9. A STUDY ON THE INTRODUCTION OF BUS RAPID TRANSIT SYSTEM IN ASIAN DEVELOPING CITIES

    Directory of Open Access Journals (Sweden)

    Thaned SATIENNAM

    2006-01-01

    Full Text Available Bus Rapid Transit (BRT has increasingly become an attractive urban transit alternative in many Asian developing cities due to its cost-effective and flexible implementation. However, it still seems to be difficult to introduce BRT to these cities because almost all of their city structures have been developed under solely a road transport development city plan and weakness of land use control gives rise to many problems, such as urban sprawl, traffic congestion, and air pollution. The purpose of this study was to introduce several strategies to support BRT implementation in Asian developing cities, such as a strategy to appropriately integrate the paratransit system into BRT system as being a feeder along a BRT corridor to supply demand. These proposed strategies were evaluated by applying demand forecasting and emission models to the BRT project plan of Bangkok Metropolitan Administration (BMA in Thailand. It was demonstrated that the proposed strategies could effectively improve the BRT ridership, traffic conditions, and air pollution emission of the entire system in Bangkok. This study could be further extended to include strategy recommendation if a BRT system were to be introduced to other Asian developing cities.

  10. Optimal Charging Schedule Planning and Economic Analysis for Electric Bus Charging Stations

    Directory of Open Access Journals (Sweden)

    Rong-Ceng Leou

    2017-04-01

    Full Text Available The battery capacity of electric buses (EB used for public transportation is greater than that of electric cars, and the charging power is also several times greater than that used in electric cars; this can result in high energy consumption and negatively impact power distribution networks. This paper proposes a framework to determine the optimal contracted power capacity and charging schedule of an EB charging station in such a way that energy costs can be reduced. A mathematical model of controlled charging, which includes the capacity and energy charges of the station, was developed to minimize costs. The constraints of the model include the charging characteristics of an EB and the operational guidelines of the bus company. A practical EB charging station was used to verify the proposed model. The financial viability of this EB charging station is also studied in this paper. The economic analysis model for this charging station considers investment and operational costs, and the operational revenue. Sensitivity analyses with respect to some key parameters are also performed in this paper. Based on actual operational routes and EB charging schemes, test results indicate that the EB charging station investment is feasible, and the planning model proposed can be used to determine optimal station power capacity and minimize energy costs.

  11. Longevity-conscious dimensioning and power management of the hybrid energy storage system in a fuel cell hybrid electric bus

    International Nuclear Information System (INIS)

    Hu, Xiaosong; Johannesson, Lars; Murgovski, Nikolce; Egardt, Bo

    2015-01-01

    Highlights: • Hybrid energy storage system is optimally sized and controlled for a hybrid bus. • Dynamic battery health model is incorporated in the optimization. • Convex programming is efficient for optimizing hybrid propulsion systems. • Optimal battery replacement strategy is explored. • Comparison to the battery-only option is made in the health-aware optimization. - Abstract: Energy storage systems (ESSs) play an important role in the performance and economy of electrified vehicles. Hybrid energy storage system (HESS) combining both lithium-ion cells and supercapacitors is one of the most promising solutions. This paper discusses the optimal HESS dimensioning and energy management of a fuel cell hybrid electric bus. Three novel contributions are added to the relevant literature. First, efficient convex programming is used to simultaneously optimize the HESS dimension (including sizes of both the lithium-ion battery pack and the supercapacitor stack) and the power allocation between the HESS and the fuel cell system (FCS) of the hybrid bus. In the combined plant/controller optimization problem, a dynamic battery State-of-Health (SOH) model is integrated to quantitatively examine the impact of the battery replacement strategy on both the HESS size and the bus economy. Second, the HESS and the battery-only ESS options are systematically compared in the proposed optimization framework. Finally, the battery-health-perceptive HESS optimization outcome is contrasted to the ideal one neglecting the battery degradation (assuming that the battery is durable over the bus service period without deliberate power regulation)

  12. KAJIAN AWAL SIMULASI KOMPUTER MODEL KEBIJAKAN PENENTUAN JUMLAH OPTIMAL ARMADA BUS RAPID TRANSIT (BRT SEMARANG

    Directory of Open Access Journals (Sweden)

    Wiwik Budiawan

    2016-04-01

    Full Text Available Keberadaan Bus Rapid Transit (BRT di Kota Semarang diharapkan dapat menjadi salah satu solusi akan permasalahan kemacetan, adanya BRT ini terutama pada trayek perjalanan koridor II, ternyata mendapatkan tanggapan positif dari masyarakat pengguna, terbukti dari meningkatnya permintaan yang terjadi dari tahun 2012 hingga 2013 yakni hampir menyentuh angka 90% dari tahun sebelumnya. Dari hasil pengamatan pada trayek perjalanan Koridor II yang telah dilakukan, ternyata diketahui bahwa pada beberapa shelter (halte terjadi permintaan yang cukup tinggi, dan akhirnya pada saat peak hour armada BRT tidak mampu menampung seluruh permintaan yang terjadi, sehingga mengakibatkan penumpang harus menunggu lebih lama untuk dilayani oleh armada tersebut. Hal tersebut memicu permasalahan baru yakni kurang optimalnya jumlah armada yang beroperasi dan juga jadwal antar keberangkatan armada yang kurang menyesuaikan kondisi ketika tingginya permintaan pada setiap halte. Adapun metode yang digunakan adalah dengan melakukan pendekatan sistem, yang selanjutnya melakukan pemodelan sistem transportasi dan simulasi computer yang terjadi pada rute perjalanan tersebut. Hasil dari penelitian ini adalah rancangan model simulasi dalam bentuk model matematis dan simulasi komputer. Variabel pengendali pada model matematis dan simulasi komputer adalah frekuensi waktu antar kedatangan armada BRT, sehingga diharapkan mengurangi panjang antrian penumpang. Kata kunci: sistem transportasi, pemodelan sistem, simulasi komputer.

  13. Modification and tuning of diesel bus engine for biogas electricity production

    Directory of Open Access Journals (Sweden)

    Sittiboon Siripornakarachai

    2007-11-01

    Full Text Available This study is to convert and tune a bus diesel engine for electricity production in a farm using biogas as fuel. The engine under study is a Hino K-13CTI 13,000 cc 24 valve turbocharged engine coupled to a 3 phase 4 pole induction motor to produce electricity at 50 Hz. Modifications include an addition of biogas carburetor for air-fuel mixing, replacing the fuel injection system with spark ignition system, reduction of compression ratio from the original 16:1 to 8:1 using a cylinder head spacer, and modification of the turbocharger waste gate so the boost pressure can be adjusted. When the induction motor is synchronized to the power grid, the running speed of the engine is 1,500 rpm. Optimal engine efficiency was achieved at 28.6% by setting the lambda factor at 1.097, ignition timing at 54o before top dead center, and the turbocharger boost at 56 kPa. With this setting, the generator power output is 134.20 kilowatt with emission of CO and NOX being 1,154 and 896 ppm respectively.

  14. Intelligent Bus Stops in the Flexible Bus Systems

    Directory of Open Access Journals (Sweden)

    Razi Iqbal

    2014-09-01

    Full Text Available The purpose of this paper is to discuss Intelligent Bus Stops in a special Demand Responsive Transit (DRT, the Flexible Bus System. These Intelligent Bus Stops are more efficient and information rich than Traditional Bus Stops. The real time synchronization of the Flexible Bus System makes it unique as compared to Traditional Bus Systems. The Main concern is to make Bus Stops intelligent and information rich. Buses are informed about the no. of passengers waiting at the upcoming Bus Stops. If there are no passengers to ride or get off on upcoming Bus Stop, the Bus can skip that Bus Stop and head towards the next Bus Stop where passenger is waiting, which will decrease the ride time of the passengers on the Bus and also the wait time of the passengers waiting on the upcoming Bus Stops. Providing more information at Bus Stops about the Destination (Time to Destination, Distance to Destination etc. and Buses (Bus Location, Arrival Time of Bus etc. makes it easier for the passengers to decide whether to ride a particular Bus or not.

  15. COMPARISON OF PARALLEL AND SERIES HYBRID POWERTRAINS FOR TRANSIT BUS APPLICATION

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhiming [ORNL; Daw, C Stuart [ORNL; Smith, David E [ORNL; Jones, Perry T [ORNL; LaClair, Tim J [ORNL; Parks, II, James E [ORNL

    2016-01-01

    The fuel economy and emissions of both conventional and hybrid buses equipped with emissions aftertreatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicate that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar CO and HC tailpipe emissions but were also predicted to have reduced NOx tailpipe emissions compared to the conventional bus in higher speed cycles. For the New York bus cycle (NYBC), which has the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus, while the parallel hybrid bus had significantly lower tailpipe emissions. All three bus powertrains were found to require periodic active DPF regeneration to maintain PM control. Plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed due to the relatively large battery capacity that is typical of the series hybrid configuration.

  16. Impact of Spanish electricity mix, over the period 2008–2030, on the Life Cycle energy consumption and GHG emissions of Electric, Hybrid Diesel-Electric, Fuel Cell Hybrid and Diesel Bus of the Madrid Transportation System

    International Nuclear Information System (INIS)

    García Sánchez, Juan Antonio; López Martínez, José María; Lumbreras Martín, Julio; Flores Holgado, María Nuria; Aguilar Morales, Hansel

    2013-01-01

    Highlights: • We assess the performance of 4 buses that run on different alternative fuel types and technologies. • The buses assessed are Fuel Cell-Hybrid Bus, Hybrid Diesel-Electric Bus, Battery Electric Bus, and a Diesel Bus. • We examine the environmental impact caused by the Life Cycle of each vehicle technology, fossil fuel and energy carrier. • Life Cycle of Battery Electric Bus shows that it has a big potential of improvement in terms of environmental impact. - Abstract: In spite of the advanced research in automotive technology, and the improvement of fuels, the road transport sector continues to be an environmental concern, since the increase in transport demand is offsetting the effects of these technological improvements. Therefore, this poses the following question: what combination of technology and fuel is more efficient in terms of energy consumption and green house gas (GHG) emissions? To fully address this question it is necessary to carry out a Life Cycle Assessment (LCA). This paper presents a global LCA of 4 buses that run on the following fuel types and technologies: (1) Fuel Cell- Hybrid Bus, (2) Hybrid Diesel-Electric Bus (series configuration), (3) Battery Electric Bus and (4) Combustion Ignition Engine Bus. The impact categories assessed are: primary energy consumption, fossil energy and GHG emissions. Among the principal results, we can conclude that the Global LCA of buses (3) and (1) (which are the more sensitive pathways to the electricity mix variation) have for the 2008–2030 period a room for improvement of 25.62% and 28.16% in terms of efficiency of fossil energy consumption and a potential GHG emission reduction of 28.70% and 30.88% respectively

  17. Preliminary concept for statewide intercity bus and rail transit system : priority corridor ranking and analysis.

    Science.gov (United States)

    2009-03-01

    This product summarizes the preliminary concept and priority corridors for development of a potential : statewide intercity bus and rail network. The concept is based upon the results of Tasks 1 through 5 of Texas : Department of Transportation Proje...

  18. Modeling transit bus fuel consumption on the basis of cycle properties.

    Science.gov (United States)

    Delgado, Oscar F; Clark, Nigel N; Thompson, Gregory J

    2011-04-01

    A method exists to predict heavy-duty vehicle fuel economy and emissions over an "unseen" cycle or during unseen on-road activity on the basis of fuel consumption and emissions data from measured chassis dynamometer test cycles and properties (statistical parameters) of those cycles. No regression is required for the method, which relies solely on the linear association of vehicle performance with cycle properties. This method has been advanced and examined using previously published heavy-duty truck data gathered using the West Virginia University heavy-duty chassis dynamometer with the trucks exercised over limited test cycles. In this study, data were available from a Washington Metropolitan Area Transit Authority emission testing program conducted in 2006. Chassis dynamometer data from two conventional diesel buses, two compressed natural gas buses, and one hybrid diesel bus were evaluated using an expanded driving cycle set of 16 or 17 different driving cycles. Cycle properties and vehicle fuel consumption measurements from three baseline cycles were selected to generate a linear model and then to predict unseen fuel consumption over the remaining 13 or 14 cycles. Average velocity, average positive acceleration, and number of stops per distance were found to be the desired cycle properties for use in the model. The methodology allowed for the prediction of fuel consumption with an average error of 8.5% from vehicles operating on a diverse set of chassis dynamometer cycles on the basis of relatively few experimental measurements. It was found that the data used for prediction should be acquired from a set that must include an idle cycle along with a relatively slow transient cycle and a relatively high speed cycle. The method was also applied to oxides of nitrogen prediction and was found to have less predictive capability than for fuel consumption with an average error of 20.4%.

  19. Modelling and Simulation of Cooperative Control for Bus Rapid Transit Vehicle Platoon in a Connected Vehicle Environment

    Directory of Open Access Journals (Sweden)

    Jiahui Liu

    2017-02-01

    Full Text Available The aim of this paper is to develop a cooperative control model for improving the operational efficiency of Bus Rapid Transit (BRT vehicles. The model takes advantage of the emerging connected vehicle technology. A connected vehicle centre is established to assign a specific reservation time interval and transmit the corresponding dynamic speed guidance to each BRT vehicle. Furthermore, a set of constraints have been set up to avoid bus queuing and waiting phenomena in downstream BRT stations. Therefore, many BRT vehicles are strategically guided to form a platoon, which can pass through an intersection with no impedance. An actual signalized intersection along the Guangzhou BRT corridor is employed to verify and assess the cooperative control model in various traffic conditions. The simulation-based evaluation results demonstrate that the proposed approach can reduce delays, decrease the number of stops, and improve the sustainability of the BRT vehicles.

  20. Enabling Bus Transit Service Quality Co-Monitoring Through Smartphone-Based Platform

    DEFF Research Database (Denmark)

    Li, Corinna; Zegras, P. Christopher; Zhao, Fang

    2017-01-01

    ’ word, meaning “agencies using public feedback to supplement official monitoring and regulation.”] bus service quality. The pilot project adapted a smartphone-based travel survey system, Future Mobility Sensing, to collect real-time customer feedback and objective operational measurements on specific...

  1. Public perception related to a hydrogen hybrid internal combustion engine transit bus demonstration and hydrogen fuel

    International Nuclear Information System (INIS)

    Hickson, Allister; Phillips, Al; Morales, Gene

    2007-01-01

    Hydrogen has been widely considered as a potentially viable alternative to fossil fuels for use in transportation. In addition to price competitiveness with fossil fuels, a key to its adoption will be public perceptions of hydrogen technologies and hydrogen fuel. This paper examines public perceptions of riders of a hydrogen hybrid internal combustion engine bus and hydrogen as a fuel source

  2. Bus systems in motor vehicles; Bussysteme im Kfz

    Energy Technology Data Exchange (ETDEWEB)

    Schule, Roland

    2008-07-01

    There is hardly any modern vehicle without a bus system. This interactive learning software explains why electric and electronic systems in motor vehicles should be linked and uses various bus types to illustrate the various alternatives, bus structures, and data types. The physical side of bus systems is gone into, the data structure is explained, and the various bus typologies are outlined. From the fundamentals of bus systems, the software proceeds to present the most important bus systems and their main properties. Subjects: Diagnosis bus, LIN bus, CAN bus, MOST bus, Bluetooth. The bus systems EIA-485, LVDS, D{sup 2}B, byteflight, and Flexray are briefly characterised. (orig.)

  3. Method for in-use measurement and evaluation of the activity, fuel use, electricity use, and emissions of a plug-in hybrid diesel-electric school bus.

    Science.gov (United States)

    Choi, Hyung-Wook; Frey, H Christopher

    2010-05-01

    The purpose of this study is to demonstrate a methodology for characterizing at high resolution the energy use and emissions of a plug-in parallel-hybrid diesel-electric school bus (PHSB) to support assessments of sensitivity to driving cycles and comparisons to a conventional diesel school bus (CDSB). Data were collected using onboard instruments for a first-of-a-kind prototype PHSB and a CDSB of the same chassis and engine, operated on actual school bus routes. The engine load was estimated on the basis of vehicle specific power (VSP) and an empirically derived relationship between VSP and engine manifold absolute pressure (MAP). VSP depends on speed, acceleration, and road grade. For the PHSB, the observed electrical discharge or recharge to the traction motor battery was characterized on the basis of VSP. The energy use and emission rates of the PHSB from tailpipe and electricity use were estimated for five real-world driving cycles and compared to the engine fuel use and emissions of the CDSB. The PHSB had the greatest advantage on arterial routes and less advantage on highway or local routes. The coupled VSP-MAP modeling approach enables assessment of a wide variety of driving conditions and comparisons of vehicles with different propulsion technologies.

  4. Electric Monopole Transition Strengths in 62Ni

    Directory of Open Access Journals (Sweden)

    Evitts L. J.

    2016-01-01

    Full Text Available Excited states in 62Ni were populated with a (p, p’ reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0, were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77−34+23 × 10−3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0 value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0 values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0 value for the 22+ to 21+ transition.

  5. Electric Monopole Transition Strengths in 62Ni

    Science.gov (United States)

    Evitts, L. J.; Garnsworthy, A. B.; Kibédi, T.; Moukaddam, M.; Alshahrani, B.; Eriksen, T. K.; Holt, J. D.; Hota, S. S.; Lane, G. J.; Lee, B. Q.; McCormick, B. P.; Palalani, N.; Reed, M. W.; Stroberg, S. R.; Stuchbery, A. E.

    2016-09-01

    Excited states in 62Ni were populated with a (p, p') reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0), were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77-34+23 × 10-3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0) value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0) values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0) value for the 22+ to 21+ transition.

  6. Miniature JPL Universal Instrument Bus

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a Universal Digital Processor Bus architecture using state of the art commercial packaging technologies. This work will transition commercial advanced- yet...

  7. Minimization of Construction Costs for an All Battery-Swapping Electric-Bus Transportation System: Comparison with an All Plug-In System

    Directory of Open Access Journals (Sweden)

    Shyang-Chyuan Fang

    2017-06-01

    Full Text Available The greenhouse gases and air pollution generated by extensive energy use have exacerbated climate change. Electric-bus (e-bus transportation systems help reduce pollution and carbon emissions. This study analyzed the minimization of construction costs for an all battery-swapping public e-bus transportation system. A simulation was conducted according to existing timetables and routes. Daytime charging was incorporated during the hours of operation; the two parameters of the daytime charging scheme were the residual battery capacity and battery-charging energy during various intervals of daytime peak electricity hours. The parameters were optimized using three algorithms: particle swarm optimization (PSO, a genetic algorithm (GA, and a PSO–GA. This study observed the effects of optimization on cost changes (e.g., number of e-buses, on-board battery capacity, number of extra batteries, charging facilities, and energy consumption and compared the plug-in and battery-swapping e-bus systems. The results revealed that daytime charging can reduce the construction costs of both systems. In contrast to the other two algorithms, the PSO–GA yielded the most favorable optimization results for the charging scheme. Finally, according to the cases investigated and the parameters of this study, the construction cost of the plug-in e-bus system was shown to be lower than that of the battery-swapping e-bus system.

  8. Using agent based modeling to assess the effect of increased Bus Rapid Transit system infrastructure on walking for transportation.

    Science.gov (United States)

    Lemoine, Pablo D; Cordovez, Juan Manuel; Zambrano, Juan Manuel; Sarmiento, Olga L; Meisel, Jose D; Valdivia, Juan Alejandro; Zarama, Roberto

    2016-07-01

    The effect of transport infrastructure on walking is of interest to researchers because it provides an opportunity, from the public policy point of view, to increase physical activity (PA). We use an agent based model (ABM) to examine the effect of transport infrastructure on walking. Particular relevance is given to assess the effect of the growth of the Bus Rapid Transit (BRT) system in Bogotá on walking. In the ABM agents are assigned a home, work location, and socioeconomic status (SES) based on which they are assigned income for transportation. Individuals must decide between the available modes of transport (i.e., car, taxi, bus, BRT, and walking) as the means of reaching their destination, based on resources and needed travel time. We calibrated the model based on Bogota's 2011 mobility survey. The ABM results are consistent with previous empirical findings, increasing BRT access does indeed increase the number of minutes that individuals walk for transportation, although this effect also depends on the availability of other transport modes. The model indicates a saturation process: as more BRT lanes are added, the increment in minutes walking becomes smaller, and eventually the walking time decreases. Our findings on the potential contribution of the expansion of the BRT system to walking for transportation suggest that ABMs may prove helpful in designing policies to continue promoting walking. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Comparison of PMAC Machines for Starter-Generator Application in a Series Hybrid-Electric Bus

    OpenAIRE

    Sinisa Jurkovic; Elias G. Strangas

    2011-01-01

    This paper presents a comparative study of outer rotor PMAC machine candidates for starter-generator application in hybrid bus with series power train configuration. PMAC machines with interior and surface mount permanent magnets are considered and compared, although a complete analysis is only carried out for the SPM. Different design aspects such as concentrated versus distributed windings as well as interior and exterior rotor structures are evaluated. Different slot numbers per pole per p...

  10. Orientation Assistance for Visually Impaired Passengers within a Bus Rapid Transit System (Transmilenio, using Satellite Geolocation

    Directory of Open Access Journals (Sweden)

    Julián Camargo

    2017-05-01

    Results: 100% of the users were able to reach their destination successfully in the pilot test. In regards to the usability perception, users highlighted features such as sound indications for setting the device and orientation guidance throughout the journey. On the other hand, one of the main difficulties found was to correctly identify the bus approaching the stop and similarly locating the corresponding boarding door, as multiple bus routes may alight in the same door. Conclusions: The device was built incorporating low-cost technologies intended to make it affordable in an eventual mass—scale production. Likewise, a discreet design was chosen so as to lessen the risk of robbery, which unfortunately is a frequent issue in the Transmilenio system due to overcrowding of buses and stations. Additionally, we remark that the prototype can be made smaller by using special—purpose circuit boards. Policy-makers may take into account these considerations for an eventual wide implementation as part of governments’ plans for mobility inclusion in mass-transport systems for disabled people, in comparison with other alternatives such as smart cell phones Language: Spanish.

  11. Economic Benefit of Introducing a Bus Rapid Transit (BRT) in Kano State Nigeria

    Science.gov (United States)

    Ahmad, K. A.; Afolabi, S.; Nda, M.; Daura, H. A.

    2018-04-01

    The objective of this study is to know the variables use in quantifying economic benefits of public transport project, contribution of public transport to economic productivity This paper attempts to provide a Road User Cost (RUC) comparison of current usage of Buses and Cars in three different stages which are the present time, do nothing and the introduction of new modes. Vehicle operating cost (VOC), value of time (VOT), pollution cost, accident cost and environmental cost are calculated in other to know the benefits for their abilities to ensure accessibility and mobility, reduce accidents and reduce environmental loss. The study stretch involves an 11.1 km of 2-lane divided carriageway road connecting Kabuga bus stop to Janguza market. Social costs which included accident costs, accident cost of cars (private modes) were found to be 50 times the accident cost of bus accidents. California Air Resource Board (CARB) model was adopted to evaluate Environmental costs. The total road user costs were then obtained to provide comparative evaluation among the study modes. Furthermore, the multiple future scenarios were created to provide understanding about the need for inclusion of other modes. In this regard, this paper provided a framework for the cost evaluation for an urban area and results indicate that buses are more cost-effective in transportation of equivalent number of passengers.

  12. Bus Rapid Transit system’s influence on urban development: An inquiry to Boston and Seoul BRT systems’ technical characteristics

    Science.gov (United States)

    Prayogi, Lutfi

    2018-03-01

    This article explores the relation between bus rapid transit (BRT) system and urban development. This article was written through a multi-staged comprehensive literature review. It includes a general overview of widely acknowledged BRT technical characteristics. It explains the approach taken in understanding the relation between BRT system provision and urban development around the system. Findings regarding the influence of Boston Silver Line 4 and 5 and Seoul BRT systems on urban development around the systems are quoted and used as case studies. Investigation on the technical characteristics of Boston SL4/5 and Seoul BRT systems are provided. This article shows that the two BRT systems that influence urban development around the systems have technical characteristics that enable the BRT systems to have high performance. However, while the quoted BRT systems can influence urban development, they have significantly different performance.

  13. Land use impacts of bus rapid transit : phase II -- effects of BRT station proximity on property values along the Boston silver line Washington Street Corridor.

    Science.gov (United States)

    2012-07-01

    The development of Bus Rapid Transit (BRT) systems is relatively recent in the U.S.; however, several systems are operating and many : more are being planned. A comprehensive understanding of the relationship between land uses and BRT systems is need...

  14. Investigating the determining factors for transit travel demand by bus mode in US metropolitan statistical areas.

    Science.gov (United States)

    2015-05-01

    Proper understanding of the nature of the transit travel demand is at the heart of transportation policy making and the success of : transit systems. Unfortunately, most of the existing studies have focused on a single or few transit systems or metro...

  15. Cost Effectiveness Analysis of Quasi-Static Wireless Power Transfer for Plug-In Hybrid Electric Transit Buses: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijuan; Gonder, Jeff; Burton, Evan; Brooker, Aaron; Meintz, Andrew; Konan, Arnaud

    2015-11-11

    This study evaluates the costs and benefits associated with the use of a plug-in hybrid electric bus and determines the cost effectiveness relative to a conventional bus and a hybrid electric bus. A sensitivity sweep analysis was performed over a number of a different battery sizes, charging powers, and charging stations. The net present value was calculated for each vehicle design and provided the basis for the design evaluation. In all cases, given present day economic assumptions, the conventional bus achieved the lowest net present value while the optimal plug-in hybrid electric bus scenario reached lower lifetime costs than the hybrid electric bus. The study also performed parameter sensitivity analysis under low market potential assumptions and high market potential assumptions. The net present value of plug-in hybrid electric bus is close to that of conventional bus.

  16. The electricity market in transition: a decoding

    International Nuclear Information System (INIS)

    Mathieu, Mathilde; Schwarz, Virginie; Chapon, Antoine; Fouquet, Doerte; Joos, Marine; Jedliczka, Marc; Siess, Damien

    2015-01-01

    A set of article proposes a discussion of the main challenges for energy transition for the architecture of the European electricity market, an interview of the responsible of the energy department within the French ministry of ecology (she addresses the issues of market, electricity system, renewable energies), a discussion of the first lessons learned from the integration of renewable energies in the electricity market, a comment on hazardous evolutions for independent producers, a discussion of the pilot stage for bidding in Germany, a discussion of false ideas and true challenges in the relationship between demand management and integration, a comment on the evolution towards a complete reform of the support system for renewable energies, and a discussion of the perspectives beyond 40 per cent of renewable energies in the French electricity mix

  17. Practical experience with IEEE 1588 high precision time synchronization in electrical substation based on IEC 61850 process bus

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.; Goraj, M.J.; McGhee, J. [RuggedCom Inc., Concord, ON (Canada)

    2010-07-01

    This paper discussed a time synchronization and dynamic multicast filtering procedure conducted on an IEC 61850 process bus. The Institute of Electrical and Electronic (IEEE) 1588 time synchronization and dynamic multicast filtering procedure was conducted at a substation equipped with non-conventional instrument transformers (NCIT) and intelligent circuit breakers. The process bus interconnected IEDs within a bay that included a real time sampled value (SV) measurement system. The system was designed to reduce the use of copper wiring and to eliminate high energy signal processes. Digitized sampled measured values were sent from the electronic instrument transformers to protect and control relays. A merging unit was used to enable the transmission of the digitized current and voltage measurements across an ethernet network. Two sampling rates were supplied for power system monitoring and protection applications. The merging units continuously sent sampling values of current and voltages acquired from primary equipment. Precision time protocol systems were discussed, and issues related to time synchronization were reviewed. A network topology was provided. 4 refs., 4 figs.

  18. Electric dipole transitions of heavy quarkonium

    Energy Technology Data Exchange (ETDEWEB)

    Pietrulewicz, Piotr [Universitaet Wien (Austria)

    2012-07-01

    In this talk we present the theoretical treatment of electric dipole transitions of heavy quarkonia within an effective field theory formalism. Inside the effective field theory called potential nonrelativistic QCD (pNRQCD) we account for the relativistic corrections to the decay rate in a systematic and model-independent way. Former results from potential model calculations are scrutinized, and a phenomenological analysis in relation to the experimental data is presented.

  19. Rethinking impact evaluation and carbon reduction analysis on electric bus vehicles in China

    Science.gov (United States)

    Li, Zhenyu; Li, Chao; Liao, Kai; Yin, Zhifang

    2018-02-01

    New energy bus vehicles (NEBVs) are expanding in China, but they have some problems such as technology, high cost and safety etc., thus NEBVs should be comprehensively evaluated from costs, technologies, environment, and based on the evaluation results, some changes should be improved. This paper firstly analyses the current status of both vehicle development and existing policies, identifies the main characteristics and the main problems in term of the economic, standard, policy, etc., by scenario analysis, forecasts the future growth from now to 2030 and calculates the emission reduction in low level scenario and high level scenario. In 2020 and 2030, 6 million and 24 million ton of CO2 emission will be reduced respectively. Finally, the paper makes a conclusion of Chinese experiences and gives some measures for the future development.

  20. Design Guidelines for Bus Transit Systems Using Liquefied Petroleum Gas (LPG) as an Alternative Fuel.

    Science.gov (United States)

    1996-09-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Methanol/Ethanol, are already being used in buses. At present, there do not exist co...

  1. Modelling multimodal transit networks : integration of bus networks with walking and cycling

    NARCIS (Netherlands)

    Brand, Judith; Hoogendoorn, S.P.; van Oort, N.; Schalkwijk, Bart

    2017-01-01

    Demand for (public) transportation is subject to dynamics affected by technological, spatial, societal and demographic aspects. The political environment, together with financial and spatial constraints limit the possibilities to address transit issues arising from growing demand through the

  2. San Antonio's 1983 Bus Passenger Survey

    Science.gov (United States)

    1983-10-01

    Many transit operators routinely collect ridership data in order to provide a : basis for the planning of bus services. Often a survey is conducted of bus : riders to determine their riding habits, their views about the quality of : current service, ...

  3. American Fuel Cell Bus Project Evaluation. Second Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses operating in the Coachella Valley area of California. The prototype AFCB was developed as part of the Federal Transit Administration's (FTA's) National Fuel Cell Bus Program. Through the non-profit consortia CALSTART, a team led by SunLine Transit Agency and BAE Systems developed a new fuel cell electric bus for demonstration. SunLine added two more AFCBs to its fleet in 2014 and another in 2015. FTA and the AFCB project team are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory to evaluate the buses in revenue service. This report summarizes the performance results for the buses through June 2015.

  4. Bus transit operational efficiency resulting from passenger boardings at park-and-ride facilities.

    Science.gov (United States)

    2016-08-01

    In order to save time and money by not driving to an ultimate destination, some urban commuters drive themselves a few miles to specially designated parking lots built for transit customers and located where trains or buses stop. The focus of this pa...

  5. Bus fuel consumption model

    Energy Technology Data Exchange (ETDEWEB)

    Zargari, S.A. [Iran Univ. of Science and Technology, Teheran (Iran, Islamic Republic of); Khan, A.M. [Carleton Univ., Ottawa, ON (Canada). Dept. of Civil and Environmental Engineering

    2000-07-01

    The interest in rapid bus transit has increased sharply with the realization that modern metropolitan areas rely on public transit to provide for strong economies and communities. As a prevention tool against traffic congestion, deteriorating air quality and rising greenhouse gas emissions, this study of bus fuel consumption was designed to assist in the planning and management of rapid bus transit. The Australian Road Research Board's (ARRB) Road Fuel Consumption Model was used as a starting point. The estimations required were realized with the help of Newtonian Mechanics. The four states of vehicular traffic were examined: acceleration, cruise, deceleration, and idle. The estimated total power required from the engine to overcome resistance forces, to run vehicle accessories and overcome internal engine friction was calculated. The data for the standard and articulated bus was obtained from OC Transpo in Ottawa. The study permitted the authors to conclude that the estimations for the parameters for power requirements and fuel consumption for heavy duty vehicles are appropriate. The methodology for the estimation of fuel consumption on the Transitway, which is part of the rapid bus transit system, proved adequate. In addition, the methodology was useful to estimate fuel savings resulting from demand management strategies with potential for modal shift. 9 refs., 6 tabs.

  6. Model predictive control-based efficient energy recovery control strategy for regenerative braking system of hybrid electric bus

    International Nuclear Information System (INIS)

    Li, Liang; Zhang, Yuanbo; Yang, Chao; Yan, Bingjie; Marina Martinez, C.

    2016-01-01

    Highlights: • A 7-degree-of-freedom model of hybrid electric vehicle with regenerative braking system is built. • A modified nonlinear model predictive control strategy is developed. • The particle swarm optimization algorithm is employed to solve the optimization problem. • The proposed control strategy is verified by simulation and hardware-in-loop tests. • Test results verify the effectiveness of the proposed control strategy. - Abstract: As one of the main working modes, the energy recovered with regenerative braking system provides an effective approach so as to greatly improve fuel economy of hybrid electric bus. However, it is still a challenging issue to ensure braking stability while maximizing braking energy recovery. To solve this problem, an efficient energy recovery control strategy is proposed based on the modified nonlinear model predictive control method. Firstly, combined with the characteristics of the compound braking process of single-shaft parallel hybrid electric bus, a 7 degrees of freedom model of the vehicle longitudinal dynamics is built. Secondly, considering nonlinear characteristic of the vehicle model and the efficiency of regenerative braking system, the particle swarm optimization algorithm within the modified nonlinear model predictive control is adopted to optimize the torque distribution between regenerative braking system and pneumatic braking system at the wheels. So as to reduce the computational time of modified nonlinear model predictive control, a nearest point method is employed during the braking process. Finally, the simulation and hardware-in-loop test are carried out on road conditions with different tire–road adhesion coefficients, and the proposed control strategy is verified by comparing it with the conventional control method employed in the baseline vehicle controller. The simulation and hardware-in-loop test results show that the proposed strategy can ensure vehicle safety during emergency braking

  7. Application-Oriented Optimal Shift Schedule Extraction for a Dual-Motor Electric Bus with Automated Manual Transmission

    Directory of Open Access Journals (Sweden)

    Mingjie Zhao

    2018-02-01

    Full Text Available The conventional battery electric buses (BEBs have limited potential to optimize the energy consumption and reach a better dynamic performance. A practical dual-motor equipped with 4-speed Automated Manual Transmission (AMT propulsion system is proposed, which can eliminate the traction interruption in conventional AMT. A discrete model of the dual-motor-AMT electric bus (DMAEB is built and used to optimize the gear shift schedule. Dynamic programming (DP algorithm is applied to find the optimal results where the efficiency and shift time of each gear are considered to handle the application problem of global optimization. A rational penalty factor and a proper shift time delay based on bench test results are set to reduce the shift frequency by 82.5% in Chinese-World Transient Vehicle Cycle (C-WTVC. Two perspectives of applicable shift rule extraction methods, i.e., the classification method based on optimal operating points and clustering method based on optimal shifting points, are explored and compared. Eventually, the hardware-in-the-loop (HIL simulation results demonstrate that the proposed structure and extracted shift schedule can realize a significant improvement in reducing energy loss by 20.13% compared to traditional empirical strategies.

  8. Wayside charging and hydrogen hybrid bus : extending the range of electric shuttle buses.

    Science.gov (United States)

    2012-09-30

    This report documents the results completed by the Center for Energy, Transportation and the Environment (CETE) at the University of Tennessee at Chattanooga (UTC) under Federal Transit Administration Cooperative Agreement TN-26-7034. This research h...

  9. Effects of new bus and rail rapid transit systems – an international review

    DEFF Research Database (Denmark)

    Ingvardson, Jesper Bláfoss; Nielsen, Otto Anker

    2018-01-01

    areas surrounding the transit line with increasing property values. Such effects are traditionally associated with attractive rail-based public transport systems. However, a statistical comparison of 41 systems did not show significant deviations between effects on property values resulting from BRT...... time, ridership and modal shifts, and (ii) the indirect strategic effects in terms of effects on property values and urban development. The review confirms the existing literature suggesting that BRT can attract many passengers if travel time reductions are significantly high. This leads to attractive...

  10. National fuel cell bus program : proterra fuel cell hybrid bus report, Columbia demonstration.

    Science.gov (United States)

    2011-10-01

    This report summarizes the experience and early results from a fuel cell bus demonstration funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by the Center for Transportation and the Environment an...

  11. IMPACTS OF BUS STOP IMPROVEMENTS

    Science.gov (United States)

    2018-03-23

    Improving bus stops by providing shelters, seating, signage, and sidewalks is relatively inexpensive and popular among riders and local officials. Making such improvements, however, is not often a priority for U.S. transit providers because of compet...

  12. Impact Safety Control Strategy for the Battery System of an Example Electric Bus

    Directory of Open Access Journals (Sweden)

    Zhen-po Wang

    2015-01-01

    Full Text Available This paper proposes a side impact safety control strategy for the battery system, aiming at defusing the hazards of unacceptable behaviors of the battery system such as high-voltage hazards. Based on some collision identification metrics, a side impact discrimination algorithm and a side impact severity algorithm are developed for electric buses. Based on the study on the time to break for power battery, the side impact discrimination algorithm response time is about 20 ms posing a great challenge to the side impact discrimination algorithm. At the same time, the reliability of the impact safety control strategy developed in this paper is evaluated for other plausible side impact signals generated by finite element analysis. The results verify that the impact safety control strategy exhibits robust performance and is able to trigger a breaking signal for power battery system promptly and accurately.

  13. Work stress, fatigue and risk behaviors at the wheel: Data to assess the association between psychosocial work factors and risky driving on Bus Rapid Transit drivers

    Directory of Open Access Journals (Sweden)

    Sergio Useche

    2017-12-01

    Full Text Available This Data in Brief (DiB article presents a hierarchical multiple linear regression model that examine the associations between psychosocial work factors and risk behaviors at the wheel in Bus Rapid Transit (BRT drivers (n=524. The data were collected using a structured self-administrable questionnaire made of measurements of wok stress (job strain and effort- reward imbalance, fatigue (need for recovery and chronic fatigue, psychological distress and demographics (professional driving experience, hours driven per day and days working per week. The data contains 4 parts: descriptive statistics, bivariate correlations between the study variables and a regression model predicting risk behaviors at the wheel and the entire study dataset. For further information, it is convenient to read the full article entitled “Stress-related Psychosocial Factors at Work, Fatigue, and Risky Driving Behavior in Bus Rapid Transport (BRT Drivers”, published in Accident Analysis & Prevention. Keywords: Professional drivers, Work stress, Fatigue, Psychological distress, Risk behaviors, Bus Rapid Transport, BRT

  14. Research and Development of Hybrid Electric Vehicles CAN-Bus Data Monitor and Diagnostic System through OBD-II and Android-Based Smartphones

    Directory of Open Access Journals (Sweden)

    Yalian Yang

    2013-01-01

    Full Text Available With the rapid development of the smartphone market, future cars seem to have more connections with intelligent cell phone and Internet. Intelligent transportation system (ITS and telematics system have become research focus in recent years. There is an increasing demand for remote monitoring and diagnostic system as the further research of hybrid electric vehicle (HEV goes on. In this paper, a remote controller area network bus (CAN-Bus data monitor and diagnostic system for HEV is presented using on board diagnostic version-II (OBD-II and Android-based smartphone. It is low-cost, convenient, and extensible with smartphone used in the system to realize communication with ELM327 and remote monitoring center wirelessly. The prototype of client and server is developed in Java language, and it is proved by the test that the system works stably and the collected data have practical values.

  15. Transition countries in the light of electricity production

    International Nuclear Information System (INIS)

    Kolin, I.

    2000-01-01

    The fall of the Berlin Wall in 1989 could be closely considered as the beginning of transition in many countries. during this period, lasting for about ten years, unavoidable fluctuations and stoppages caused degradation of electricity production and economic decline as well. This can be mathematically evaluated by means of equation for electricity production, valid before the fall of the Berlin Wall. However, electricity decrease has not been the same in all the countries. Therefore, in order to investigate and evaluate the transition process in the light of electricity production, eight transition states, including croatia, are analysed and mutually compared. (author)

  16. Electrical valley filtering in transition metal dichalcogenides

    Science.gov (United States)

    Hsieh, Tzu-Chi; Chou, Mei-Yin; Wu, Yu-Shu

    2018-03-01

    This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and perform the study with both a k .p -based analytic method and a recursive Green's function-based numerical method. The study yields the transmission coefficient as a function of incident energy and transverse wave vector, for holes going through lateral quantum barriers oriented in either armchair or zigzag directions, in both homogeneous and heterogeneous systems. The main findings are the following: (1) The tunneling current valley polarization increases with increasing barrier width or height; (2) both the valley-orbit interaction and band structure warping contribute to valley-dependent tunneling, with the former contribution being manifest in structures with asymmetric potential barriers, and the latter being orientation dependent and reaching maximum for transmission in the armchair direction; and (3) for transmission ˜0.1 , a tunneling current valley polarization of the order of 10 % can be achieved.

  17. Impact of Distribution Feeders that do not have Voltage Regulators on the number of Charged Electric Vehicles using IEEE 34 Bus Test Feeder

    Energy Technology Data Exchange (ETDEWEB)

    Allehyani, Ahmed [University of Southern California, Department of Electrical Engineering; Beshir, Mohammed [University of Southern California, Department of Electrical Engineering

    2015-02-01

    Voltage regulators help maintain an acceptable voltage profile for the system. This paper discusses the effect of installing voltage regulators to the system to fix the voltage drop resulting from the electrical vehicles loading increase when they are being charged. The effect will be studied in the afternoon, when the peak load occurs, using the IEEE 34 bus test feeder. First, only one spot node is used to charge the electric vehicles while a voltage regulator is present. Second, five spot nodes are loaded at the same time to charge the electric vehicles while voltage regulators are installed at each node. After that, the impact of electric vehicles on distribution feeders that do not have voltage regulators will appear.

  18. Phonon-assisted transitions in crossed electric and magnetic fields

    International Nuclear Information System (INIS)

    Hassan, A.R.

    1980-05-01

    A theory of the effect of a crossed electric, E, and magnetic, H, fields in the indirect transitions in semiconductors is developed. A semi-classical treatment is adopted where the electric field is considered as a small perturbation. A numerical application to GaP gives the limiting values of E/H valid to this approach. (author)

  19. Global Optimal Energy Management Strategy Research for a Plug-In Series-Parallel Hybrid Electric Bus by Using Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2013-01-01

    Full Text Available Energy management strategy influences the power performance and fuel economy of plug-in hybrid electric vehicles greatly. To explore the fuel-saving potential of a plug-in hybrid electric bus (PHEB, this paper searched the global optimal energy management strategy using dynamic programming (DP algorithm. Firstly, the simplified backward model of the PHEB was built which is necessary for DP algorithm. Then the torque and speed of engine and the torque of motor were selected as the control variables, and the battery state of charge (SOC was selected as the state variables. The DP solution procedure was listed, and the way was presented to find all possible control variables at every state of each stage in detail. Finally, the appropriate SOC increment is determined after quantizing the state variables, and then the optimal control of long driving distance of a specific driving cycle is replaced with the optimal control of one driving cycle, which reduces the computational time significantly and keeps the precision at the same time. The simulation results show that the fuel economy of the PEHB with the optimal energy management strategy is improved by 53.7% compared with that of the conventional bus, which can be a benchmark for the assessment of other control strategies.

  20. Electricity in european economies in transition

    International Nuclear Information System (INIS)

    1994-01-01

    This study examines the electricity supply industries in the European members of the former Unified Power System/interconnected Power Systems (UPS/IPS): Belarus, Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Moldova, Poland, Romania, Russia, Slovakia and Ukraine. It explores the transformation process in the electricity sector over the past five years, its relationship to other changes in the region and possible future trends. Subjects covered include structure and regulation, demand, primary fuel availability, generating capacity, financing, tariffs, interconnections and trade

  1. Bus basics

    International Nuclear Information System (INIS)

    Dobinson, R.W.

    1983-01-01

    The aims of this course are: 1. To introduce the general concepts of buses used to interconnect processors, perpherals, and instrumentation. 2. To classify, albeit crudely, different types of bus systems. 3. To give some examples of past, present, and future buses as applied to the field of high-energy physics, including some details of software. 4. To provide references for further study. (orig.)

  2. Turmoil and transition: Electric utility industry trends

    International Nuclear Information System (INIS)

    1994-06-01

    In a review of electric utility industry trends, focusing on North America, it is noted that four critical influences are dominant: competition in the electricity supply business; technological advances; the recognized need for environmental protection; and a favoring of market economics and customer choice. As energy costs rose in the 1970s and 1980s, electricity usage growth rates decreased and demand side management became an accepted alternative to building new power plants. In large areas of Canada and the USA, substantial surplus generation capacity arose, transmission linkages improved, and regional electricity markets developed. Privatization measures in the British electric sector were closely studied in North America and electric markets in the USA were pushed toward more competition with the 1992 Energy Policy Act. Non-utility generators have entered the market, including industrial companies, pipeline companies, independent renewable-energy providers, and power companies set up by the utilities themselves. Power pools may evolve into regional transmission grids in which the transmission owning utilities would exchange their lines for an interest in the grid. California is likely to lead in opening access to transmission on a regional scale. Distribution systems are likely to remain a regulated monopoly as before. Substantial change is expected in customer services as functions such as power purchase and conservation are being performed by independent companies. Other possible developments in the industry include emissions trading and spot markets for power. The implications of these trends for British Columbia Hydro are discussed

  3. Electric grids and energy transition in Europe

    International Nuclear Information System (INIS)

    Cruciani, Michel

    2015-06-01

    Focussing on electricity, this report proposes an analysis of the main elements in favour of large investments in electric grids, while notably outlining technical or economic uncertainties as well as possible political consequences such as compatibility of a largely interconnected European network with a free choice of energy sources (as specified in the Lisbon Treaty), and responsibility for the States in terms of supply security. The author first describes the present situation: overview of the regulatory framework of the liberalization process. The second part addresses challenges which emerged with the European commitment in favour of renewable sources of electricity and the emergence of new needs, notably regarding electric vehicles. It also presents measures aimed at supporting the development of networks. The third part introduces a discussion about the relevancy of this development by highlighting, on the one hand, the fragility of economic perspectives, and on the other hand, the necessity to address future consequences of a major increase of interconnections within the European electric grid. Some recommendations are finally proposed. Examples and specific analysis more particularly concern Germany, Spain, France, Italy and the United-Kingdom

  4. Electricity storage - A challenge for energy transition

    International Nuclear Information System (INIS)

    Bart, Jean-Baptiste; Nekrasov, Andre; Pastor, Emmanuel; Benefice, Emmanuel; Brincourt, Thierry; Cagnac, Albannie; Brisse, Annabelle; Jeandel, Elodie; Lefebvre, Thierry; Penneau, Jean-Francois; Radvanyi, Etienne; Delille, Gautier; Hinchliffe, Timothee; Lancel, Gilles; Loevenbruck, Philippe; Soler, Robert; Stevens, Philippe; Torcheux, Laurent

    2017-01-01

    After a presentation of the energetic context and of its issues, this collective publication proposes presentations of various electricity storage technologies with a distinction between direct storage, thermal storage and hydrogen storage. As far as direct storage is concerned, the following options are described: pumped energy transfer stations or PETS, compressed air energy storage or CAES, flywheels, various types of electrochemical batteries (lead, alkaline, sodium, lithium), metal air batteries, redox flow batteries, and super-capacitors. Thermal storage comprises power-to-heat and heat-to-power technologies. Hydrogen can be stored under different forms (compressed gas, liquid), in saline underground cavities, or by using water electrolysis and fuel cells. The authors propose an overview of the different services provided by energy storage to the electricity system, and discuss the main perspectives and challenges for tomorrow's storage (electric mobility, integration of renewable energies, electrification of isolated areas, scenarios of development)

  5. Fuel cell bus operation, system investigation H2 bus

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The WP covers two tasks: - Prepartion of Technical Catalogue: In cooperation with ICIL, AR have compiled a technical catalogue, providing the impartial descriptions, both of existing technology and regulations, and the likely future developments of these, as to remedy the first problem faced by a potential hydrogen bus fleet operator viz the absence of an impartial description of the available vehicle and fuels systems together with the absence of a description of regulatory and safety factors which need consideration. - Fuel Cell Bus Operation - System Investigation H 2 Bus: The application of fuel cell electric generation systems to hybrid electrical buses or electrical busses without any storage system on board is considered. The task will cover safety and environmental aspects, a cost estimate and a market evaluation. (orig.)

  6. Planning ahead for livable communities along the Powell–Division Bus Rapid Transit : neighborhood conditions and change.

    Science.gov (United States)

    2017-07-04

    New transit investments can be a double-edged sword for disadvantaged communities (e.g., those included in environmental justice and Title VI protected classes). Transit investments improve communities mobility and access, and may improve health w...

  7. Examining Diverse World Examples in Transit Fare Collection Systems for Bus and a Model System for Ankara

    Directory of Open Access Journals (Sweden)

    Seda Hatipoğlu

    2017-12-01

    Full Text Available The migration from the rural to urban areas since Industrial Revolution up to present has resulted in a global and significant urbanization phenomenon. Transportation, due to the increasing population in the cities, stands out as one of the major problems. Convenient transportation in the cities depends primarily on an efficient and productive public transportation system. Enable to use public transportation system in efficient, pricing varieties and fare payment options/ medias are applied in the transportation are very important. In order public transportation system to be efficient pricing variations and fare payment collection methods should be considered. Pricing varieties increase demands for public transportation and the ease of fare payment increases speed and capacity of public transportation. In this study, bus pricing policies and fare payment options in the cities of Geneva, London, Tokyo and Curitiba which are prominent with successful public transportation policies are examined and practice proposals are presented for the city of Ankara City.

  8. Transition-cost issues for a restructuring US electricity industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Utilities regulators can use a variety of approaches to calculate transition costs. We categorized these approaches along three dimensions. The first dimension is the use of administrative vs. market procedures to value the assets in question. Administrative approaches use analytical techniques to estimate transition costs. Market valuation relies on the purchase price of particular assets to determine their market values. The second dimension concerns when the valuation is done, either before or after the restructuring of the electricity industry. The third dimension concerns the level of detail involved in the valuation, what is often called top-down vs. bottom-up valuation. This paper discusses estimation approaches, criteria to assess estimation methods, specific approaches to estimating transition costs, factors that affect transition-cost estimates, strategies to address transition costs, who should pay transition costs, and the integration of cost recovery with competitive markets.

  9. Energetic transition in the electric sector: Brazilian case

    International Nuclear Information System (INIS)

    Jannuzzi, Gilberto de Martino

    1999-01-01

    The Brazilian electric sector is essentially based on a source of renewable energy -hydroelectricity, and the national economy has increased its dependence of the electricity. The use of the electricity for unit of GDP increased in continuous form from 1970 and the country has serious difficulties in the financing of the expansion of the electric production. Energetic politics, in what concerns to the sustainable development in the Brazilian case, should direct its efforts toward a bigger investment in efficiency and energy conservation. a bigger use of supply options that they are renewable and decentralized will depend on high degree of the regulation of the electric sector during the privatization. The transition stage of the Brazilian electric sector will imply more efforts toward a handling based on the demand and a bigger efficiency

  10. A hybrid algorithm combining EKF and RLS in synchronous estimation of road grade and vehicle' mass for a hybrid electric bus

    Science.gov (United States)

    Sun, Yong; Li, Liang; Yan, Bingjie; Yang, Chao; Tang, Gongyou

    2016-02-01

    This paper proposes a novel hybrid algorithm for simultaneously estimating the vehicle mass and road grade for hybrid electric bus (HEB). First, the road grade in current step is estimated using extended Kalman filter (EKF) with the initial state including velocity and engine torque. Second, the vehicle mass is estimated twice, one with EKF and the other with recursive least square (RLS) using the estimated road grade. A more accurate value of the estimated mass is acquired by weighting the trade-off between EKF and RLS. Finally, the road grade and vehicle mass thus obtained are used as the initial states for the next step, and two variables could be decoupled from the nonlinear vehicle dynamics by performing the above procedure repeatedly. Simulation results show that in different starting conditions, the proposed algorithm provides higher accuracy and faster convergence speed, compared with the results using EKF or RLS alone.

  11. Electric field dependence of excess electrical conductivity below transition temperature in thin superconducting lead films

    Energy Technology Data Exchange (ETDEWEB)

    Ashwini Kumar, P K; Duggal, V P [Delhi Univ. (India). Dept. of Physics and Astrophysics

    1976-01-26

    Results of measurements of the electric field dependence of the excess electrical conductivity are reported in thin superconducting lead films below the transition temperature. It is observed that the normal state sheet resistance has some effect on the nonlinearity but the theory of Yamaji still fits well to the experimental data.

  12. A robust H∞ control-based hierarchical mode transition control system for plug-in hybrid electric vehicle

    Science.gov (United States)

    Yang, Chao; Jiao, Xiaohong; Li, Liang; Zhang, Yuanbo; Chen, Zheng

    2018-01-01

    To realize a fast and smooth operating mode transition process from electric driving mode to engine-on driving mode, this paper presents a novel robust hierarchical mode transition control method for a plug-in hybrid electric bus (PHEB) with pre-transmission parallel hybrid powertrain. Firstly, the mode transition process is divided into five stages to clearly describe the powertrain dynamics. Based on the dynamics models of powertrain and clutch actuating mechanism, a hierarchical control structure including two robust H∞ controllers in both upper layer and lower layer is proposed. In upper layer, the demand clutch torque can be calculated by a robust H∞controller considering the clutch engaging time and the vehicle jerk. While in lower layer a robust tracking controller with L2-gain is designed to perform the accurate position tracking control, especially when the parameters uncertainties and external disturbance occur in the clutch actuating mechanism. Simulation and hardware-in-the-loop (HIL) test are carried out in a traditional driving condition of PHEB. Results show that the proposed hierarchical control approach can obtain the good control performance: mode transition time is greatly reduced with the acceptable jerk. Meanwhile, the designed control system shows the obvious robustness with the uncertain parameters and disturbance. Therefore, the proposed approach may offer a theoretical reference for the actual vehicle controller.

  13. Lifecycle cost assessment and carbon dioxide emissions of diesel, natural gas, hybrid electric, fuel cell hybrid and electric transit buses

    International Nuclear Information System (INIS)

    Lajunen, Antti; Lipman, Timothy

    2016-01-01

    This paper evaluates the lifecycle costs and carbon dioxide emissions of different types of city buses. The simulation models of the different powertrains were developed in the Autonomie vehicle simulation software. The carbon dioxide emissions were calculated both for the bus operation and for the fuel and energy pathways from well to tank. Two different operating environment case scenarios were used for the primary energy sources, which were Finland and California (USA). The fuel and energy pathways were selected appropriately in relation to the operating environment. The lifecycle costs take into account the purchase, operating, maintenance, and possible carbon emission costs. Based on the simulation results, the energy efficiency of city buses can be significantly improved by the alternative powertrain technologies. Hybrid buses have moderately lower carbon dioxide emissions during the service life than diesel buses whereas fully-electric buses have potential to significantly reduce carbon dioxide emissions, by up to 75%. The lifecycle cost analysis indicates that diesel hybrid buses are already competitive with diesel and natural gas buses. The high costs of fuel cell and battery systems are the major challenges for the fuel cell hybrid buses in order to reduce lifecycle costs to more competitive levels. - Highlights: • Alternative powertrains can significantly improve energy efficiency of transit buses. • Operating environment has an important impact on the lifecycle costs of buses. • Diesel hybrid buses are already cost effective solution for public transportation. • The cost of fuel cell technology is the major challenge for fuel cell hybrid buses. • Fully-electric buses have potential to significantly reduce carbon dioxide emissions.

  14. Cubic to hexagonal phase transition induced by electric field

    Czech Academy of Sciences Publication Activity Database

    Giacomelli, F. C.; Silveira, N.; Nallet, F.; Černoch, Peter; Steinhart, Miloš; Štěpánek, Petr

    2010-01-01

    Roč. 43, č. 9 (2010), s. 4261-4267 ISSN 0024-9297 R&D Projects: GA ČR GAP208/10/1600 Institutional research plan: CEZ:AV0Z40500505 Keywords : order to order transition (OOT) * electric field * block copolymers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.838, year: 2010

  15. The Bus Station Spacing Optimization Based on Game Theory

    Directory of Open Access Journals (Sweden)

    Changjiang Zheng

    2015-01-01

    Full Text Available With the development of city, the problem of traffic is becoming more and more serious. Developing public transportation has become the key to solving this problem in all countries. Based on the existing public transit network, how to improve the bus operation efficiency, and reduce the residents transit trip cost has become a simple and effective way to develop the public transportation. Bus stop spacing is an important factor affecting passengers’ travel time. How to set up bus stop spacing has become the key to reducing passengers’ travel time. According to comprehensive traffic survey, theoretical analysis, and summary of urban public transport characteristics, this paper analyzes the impact of bus stop spacing on passenger in-bus time cost and out-bus time cost and establishes in-bus time and out-bus time model. Finally, the paper gets the balance best station spacing by introducing the game theory.

  16. Strategies to address transition costs in the electricity industry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L.; Hadley, S.; Hirst, E.

    1996-07-01

    Transition costs are the potential monetary losses that electric- utility shareholders, ratepayers, or other parties might experience because of structural changes in the electricity industry. Regulators, policy analysts, utilities, and consumer groups have proposed a number of strategies to address transition costs, such as immediately opening retail electricity markets or delaying retail competition. This report has 3 objectives: identify a wide range of strategies available to regulators and utilities; systematically examine effects of strategies; and identify potentially promising strategies that may provide benefits to more than one set of stakeholders. The many individual strategies are grouped into 6 major categories: market actions, depreciation options, rate-making actions, utility cost reductions, tax measures, and other options. Of the 34 individual strategies, retail ratepayers have primary or secondary responsibility for paying transition costs in 19 of the strategies, shareholders in 12, wheeling customers in 11, taxpayers in 8, and nonutility suppliers in 4. Most of the strategies shift costs among different segments of the economy, although utility cost reductions can be used to offset transition costs. Most of the strategies require cooperation of other parties, including regulators, to be implemented successfully; financial stakeholders must be engages in negotiations that hold the promise of shared benefits. Only by rejecting ``winner-take-all`` strategies will the transition-cost issue be expeditiously resolved.

  17. Clean air program : design guidelines for bus transit systems using compressed natural gas as an alternative fuel

    Science.gov (United States)

    1996-06-01

    This report documents design guidelines for the safe use of Compressed Natural Gas (CNG). The report is designed to provide guidance, information on safe industry practices, applicable national codes and standards, and reference data that transit age...

  18. Optimizing Tailored Bus Bridging Paths

    NARCIS (Netherlands)

    Gu, Wei; Yu, Jie; Ji, Yuxiong; van der Gun, J.P.T.; Pel, A.J.; Zhang, H. Michael; van Arem, B.

    2017-01-01

    Metro disruptions due to unexpected events reduce transit system reliability, resulting in significant productivity loss and long passenger delays. Bus bridging strategy is often used to connect stations affected by metro disruptions such that passengers could continue their journey. The literature

  19. Fuel Cell Buses in U.S. Transit Fleets : Current Status 2014

    Science.gov (United States)

    2014-12-03

    This report, published annually, summarizes the progress of fuel cell electric bus (FCEB) development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. Various stakeholders, including d...

  20. Fuel Cell Buses in U.S. Transit Fleets : Current Status 2015

    Science.gov (United States)

    2015-12-01

    This report, published annually, summarizes the progress of fuel cell electric bus (FCEB) development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of ...

  1. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2017

    Science.gov (United States)

    2017-11-01

    This report, published annually, summarizes the progress of fuel cell electric bus (FCEB) development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of ...

  2. The electric monopole transition: Nuclear structure, and nuclear spectroscopy

    International Nuclear Information System (INIS)

    Zganiar, E.F.

    1992-01-01

    The electric monopole (E0) transition process provides unique information on the structure of nuclei. For example, δI=0 transitions between nuclear configurations of different shape have enhanced EO components. The authors have observed I π→Iπ (I=0) transitions in 185 Pt and 184 Pt which are pure E0. This is unprecedented. Further, they have initiated searches for the location of the superdeformed band in 192 Hg utilizing internal conversion spectroscopy and, for the first time, internal pair spectroscopy. Additionally, the lifetime of the 0 + 2 level in 188 Hg was measured with a newly developed picosecond lifetime system which utilized the 0 + 2 →0 + 1 E0 internal conversion transition as an energy gate and its associated atomic X-ray as a fast trigger. The role of the E0 internal conversion process in the study of nuclear structure and as a tool in nuclear spectroscopy are discussed

  3. Europe’s electricity regime: restoration or thorough transition

    Directory of Open Access Journals (Sweden)

    Aviel Verbruggen

    2015-06-01

    Full Text Available Concerns about climate change, diminishing social acceptance of traditional fuels, and technological innovations have led several countries to pursue energy transition strategies, typically by massive diffusion of renewable electricity supplies. The German ‘Energiewende’ has been successful so far in terms of deploying renewable power, mainly by applying particular feed-in tariffs, and by bundling public, academic, industrial and political support. So far though, only few EU member states proceed with a similar transition. In March 2014 CEOs of Europe’s major energy companies publicly opposed a fast and thorough transformation of electricity supplies to become fully renewable. In April 2014 the European Commission published new state aid guidelines, generally mandating renewable energy support mechanisms (premiums, tenders of lesser performance than regularly adjusted, specific feed-in tariffs. The new guidelines are likely to be pernicious for the fast deployment of renewable electricity supplies. In light of these challenges, this position paper highlights two implications of power sector transitions. First, the engineering-economics theory of power generation systems needs fundamental revision, mainly since a growing share of power sources no longer function on command. Second, and based on the experience in Germany, the paper sketches out a strategy for a thorough transition of the power sector, which, in the end, also entails normative judgements. Deep changes in energy systems and associated ways of living require societal consensus building based on ethical considerations.

  4. Temperature-dependent electrical property transition of graphene oxide paper

    International Nuclear Information System (INIS)

    Huang Xingyi; Jiang Pingkai; Zhi Chunyi; Golberg, Dmitri; Bando, Yoshio; Tanaka, Toshikatsu

    2012-01-01

    Reduction of graphene oxide is primarily important because different reduction methods may result in graphene with totally different properties. For systematically exploring the reduction of graphene oxide, studies of the temperature-dependent electrical properties of graphene oxide (GO) are urgently required. In this work, for the first time, broadband dielectric spectroscopy was used to carry out an in situ investigation on the transition of the electrical properties of GO paper from −40 to 150 °C. The results clearly reveal a very interesting four-stage transition of electrical properties of GO paper with increasing temperature: insulator below 10 °C (stage 1), semiconductor at between 10 and 90 °C (stage 2), insulator at between 90 and 100 °C (stage 3), and semiconductor again at above 100 °C (stage 4). Subsequently, the transition mechanism was discussed in combination with detailed dielectric properties, microstructure and thermogravimetric analyses. It is suggested that the temperature-dependent transition of electronic properties of GO is closely associated with the ion mobility, water molecules removal and the reduction of GO in the GO paper. Most importantly, the present work clearly demonstrates the reduction of GO paper starts at above 100 °C. (paper)

  5. A Pontryagin Minimum Principle-Based Adaptive Equivalent Consumption Minimum Strategy for a Plug-in Hybrid Electric Bus on a Fixed Route

    Directory of Open Access Journals (Sweden)

    Shaobo Xie

    2017-09-01

    Full Text Available When developing a real-time energy management strategy for a plug-in hybrid electric vehicle, it is still a challenge for the Equivalent Consumption Minimum Strategy to achieve near-optimal energy consumption, because the optimal equivalence factor is not readily available without the trip information. With the help of realistic speeding profiles sampled from a plug-in hybrid electric bus running on a fixed commuting line, this paper proposes a convenient and effective approach of determining the equivalence factor for an adaptive Equivalent Consumption Minimum Strategy. Firstly, with the adaptive law based on the feedback of battery SOC, the equivalence factor is described as a combination of the major component and tuning component. In particular, the major part defined as a constant is applied to the inherent consistency of regular speeding profiles, while the second part including a proportional and integral term can slightly tune the equivalence factor to satisfy the disparity of daily running cycles. Moreover, Pontryagin’s Minimum Principle is employed and solved by using the shooting method to capture the co-state dynamics, in which the Secant method is introduced to adjust the initial co-state value. And then the initial co-state value in last shooting is taken as the optimal stable constant of equivalence factor. Finally, altogether ten successive driving profiles are selected with different initial SOC levels to evaluate the proposed method, and the results demonstrate the excellent fuel economy compared with the dynamic programming and PMP method.

  6. A High-Speed Target-Free Vision-Based Sensor for Bus Rapid Transit Viaduct Vibration Measurements Using CMT and ORB Algorithms

    Directory of Open Access Journals (Sweden)

    Qijun Hu

    2017-06-01

    Full Text Available Bus Rapid Transit (BRT has become an increasing source of concern for public transportation of modern cities. Traditional contact sensing techniques during the process of health monitoring of BRT viaducts cannot overcome the deficiency that the normal free-flow of traffic would be blocked. Advances in computer vision technology provide a new line of thought for solving this problem. In this study, a high-speed target-free vision-based sensor is proposed to measure the vibration of structures without interrupting traffic. An improved keypoints matching algorithm based on consensus-based matching and tracking (CMT object tracking algorithm is adopted and further developed together with oriented brief (ORB keypoints detection algorithm for practicable and effective tracking of objects. Moreover, by synthesizing the existing scaling factor calculation methods, more rational approaches to reducing errors are implemented. The performance of the vision-based sensor is evaluated through a series of laboratory tests. Experimental tests with different target types, frequencies, amplitudes and motion patterns are conducted. The performance of the method is satisfactory, which indicates that the vision sensor can extract accurate structure vibration signals by tracking either artificial or natural targets. Field tests further demonstrate that the vision sensor is both practicable and reliable.

  7. Network integration modelling of feeder and BRT(bus rapid transit) to reduce the usage of private vehicles in Palembang’s suburban area

    Science.gov (United States)

    Nur'afalia, D.; Afifa, F.; Rubianto, L.; Handayeni, K. D. M. E.

    2018-01-01

    The aim of this research is to determine the optimal feeder network route that integrates with BRT (Bus Rapid Transit). Palembang, a high growing population city with unresolved transportation demand sector. BRT as main public transportation could not fulfill people’s demand in transportation, especially in Alang-Alang Lebar sub-district. As an impact, the usage of private vehicles increases along the movement toward the city center. The concept of Network Integration that integrates feeder network with BRT is expected to be a solution to suppress the rate of private vehicles’ usage and to improve public transportation service, so that the use of BRT will be increased in the suburban area of Palembang. The method used to identifying the optimal route using Route Analysis method is route analysis using Tranetsim 0.4. The best route is obtained based on 156 movement samples. The result is 58,7% from 199 mobility’s potency of private vehicle usage’s can be reduced if there is a feeder network’s route in Alang-Alang Lebar’s sub-district. From the result, the existance of integration between feeder network and BRT is potential enough to reduce the usage of private vehicles and supports the sustainability of transportation mobility in Palembang City.

  8. Bus accident severity and passenger injury: evidence from Denmark

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Kaplan, Sigal

    2014-01-01

    Purpose Bus safety is a concern not only in developing countries, but also in the U.S. and Europe. In Denmark, disentangling risk factors that are positively or negatively related to bus accident severity and injury occurrence to bus passengers can contribute to promote safety as an essential...... principle of sustainable transit and advance the vision “every accident is one too many”. Methods Bus accident data were retrieved from the national accident database for the period 2002–2011. A generalized ordered logit model allows analyzing bus accident severity and a logistic regression enables...... examining occurrence of injury to bus passengers. Results Bus accident severity is positively related to (i) the involvement of vulnerable road users, (ii) high speed limits, (iii) night hours, (iv) elderly drivers of the third party involved, and (v) bus drivers and other drivers crossing in yellow or red...

  9. American Fuel Cell Bus Project Evaluation: Third Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jeffers, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-05-01

    This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses operating in the Coachella Valley area of California. The prototype AFCB, which was developed as part of the Federal Transit Administration's (FTA) National Fuel Cell Bus Program, was delivered to SunLine in November 2011 and was put in revenue service in mid-December 2011. Two new AFCBs with an upgraded design were delivered in June/July of 2014 and a third new AFCB was delivered in February 2015. FTA and the AFCB project team are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory to evaluate the buses in revenue service. This report covers the performance of the AFCBs from July 2015 through December 2016.

  10. Sustainability in Electricity Markets. Study for the Dutch Transition Platform on Sustainable Electricity

    International Nuclear Information System (INIS)

    2005-12-01

    The current energy system is not sustainable. This situation is liable to lead to serious and costly consequences in the long term. The two most important themes to be addressed are climate change and securing energy supplies, particularly in view of the increasing dependency on fossil fuels from geo-politically unstable regions. That is why the Dutch government has decided to strive for a transition towards a Sustainable Energy System. The aim of the energy transition is to transform the current energy system over the coming decades into a sustainable energy system. The participants in this Energy Transition have established six themes for achieving a sustainable energy economy within 50 years. Within these themes experiments are being conducted, experiments that ensure that the final aims become clearer and feasible. Market participants, scientific and civil organizations, and government agencies are taking the lead in each of the six themes: (a) Green raw materials; (b) Sustainable Mobility; (c) Chain Efficiency; (d) New Gas; (e) Sustainable Electricity; (f) Energy in the built environment. This document provides input for the theme on Sustainable Electricity. The Dutch Ministry of Economic Affairs together with SenterNovem is preparing a Platform Renewable Electricity Supply. In this Platform representatives from different stakeholders are to take part. The platform is meant to stimulate concrete actions/initiatives towards sustainable electricity supply. SenterNovem has asked PricewaterhouseCoopers (PwC) to make an international inventory of electricity market developments, with a focus on the impact for future sustainable electricity supply. The question which options for electricity generation are the most suitable for a sustainable electricity supply will be dealt with by KEMA (a Dutch research institute for the electric power industry)

  11. Transition costs in the electricity industry: A summary of issues

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L.; Hirst, E.; Hadley, S.

    1996-10-01

    Progress is evident as the restructuring debate in the U.S. electricity industry completes its third year. The Federal Energy Regulatory Commission released a final rule on transmission open access-a key element to facilitate more efficient wholesale markets. The majority of states have initiated investigations or discussions on restructuring retail markets. Yet hurdles remain in formulating and implementing state-level restructuring proposals. Perhaps foremost among these hurdles is the issue of transition costs (the potential monetary losses experienced by utilities, consumers, and other economic actors as a result of government initiatives to transform electricity generation from a regulated to a competitive market). Transition costs are approximately equal to the difference between the embedded cost for generation services under traditional cost-of-service regulation and the competitive-market price for power. When government takes action to open current monopoly franchises to multiple generation providers and the competitive-market price falls below embedded generation costs, then transition costs will arise. Transition costs will include one or more of the following four classes of costs: (1) assets, primarily utility-owned power plants; (2) liabilities, primarily long-term power-purchase and fuel-supply contracts; (3) regulatory assets, including deferred expenses and costs that regulators allow utilities to place on their balance sheets; and (4) public-policy programs, such as energy efficiency, low-income programs, and research and development. What is at issue in the transition-cost debate? The debate turns on four questions: (1) How large are the potential transition costs from restructuring? (2) How are these costs estimated? (3) What, if anything, might be done to address these costs? (4) Who will ultimately pay for any remaining costs and how? This paper summarizes some of the key results from a project at ORNL that addresses these four questions.

  12. Electrically induced phase transition in GeSbTe alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, Gunnar; Schlockermann, Carl; Woda, Michael; Wuttig, Matthias [I. Physikalisches Institut Ia, RWTH Aachen, 52056 Aachen (Germany)

    2008-07-01

    While phase change materials have already successfully been applied in rewriteable optical data storage, they are now also promising to form the basis for novel non-volatile electrical data storage devices. To understand the physical concepts of these so-called Phase Change Random Access Memory (PCRAM) it is mandatory to gain a deeper insight into the switching process between the highly resistive amorphous and the lowly resistive crystalline phase. The fast phase transitions between the amorphous and crystalline state of GeSbTe-based alloys has so far often been studied using pulsed laser irradiation. In this work an alternative approach is employed to investigate this transition. Electrical pulses are used to rapidly and reversibly switch between the two states. For these experiments a setup was built with a specially designed contacting circuit board to meet the requirements of electrical measurements on a nanosecond timescale. The influence of the pulse parameters on the change of device resistance was determined for different initial states. Furthermore the high time resolution of 0.4 ns allows investigation of transient electrical effects like the so-called threshold switching first described by Ovshinsky in the late 1960s.

  13. Electrically induced phase transition in GeSbTe alloys

    International Nuclear Information System (INIS)

    Bruns, Gunnar; Schlockermann, Carl; Woda, Michael; Wuttig, Matthias

    2008-01-01

    While phase change materials have already successfully been applied in rewriteable optical data storage, they are now also promising to form the basis for novel non-volatile electrical data storage devices. To understand the physical concepts of these so-called Phase Change Random Access Memory (PCRAM) it is mandatory to gain a deeper insight into the switching process between the highly resistive amorphous and the lowly resistive crystalline phase. The fast phase transitions between the amorphous and crystalline state of GeSbTe-based alloys has so far often been studied using pulsed laser irradiation. In this work an alternative approach is employed to investigate this transition. Electrical pulses are used to rapidly and reversibly switch between the two states. For these experiments a setup was built with a specially designed contacting circuit board to meet the requirements of electrical measurements on a nanosecond timescale. The influence of the pulse parameters on the change of device resistance was determined for different initial states. Furthermore the high time resolution of 0.4 ns allows investigation of transient electrical effects like the so-called threshold switching first described by Ovshinsky in the late 1960s

  14. 76 FR 68819 - State of Good Repair Bus and Bus Facilities Discretionary Program Funds

    Science.gov (United States)

    2011-11-07

    ... Availability on June 24, 2011. The SGR Initiative makes funds available to public transit providers to finance capital projects to replace, rehabilitate, and purchase buses and related equipment and to construct bus...

  15. 76 FR 37393 - FY 2011 Discretionary Livability Funding Opportunity; Section 5309 Bus and Bus Facilities...

    Science.gov (United States)

    2011-06-27

    ... 90 percent Federal share for the total cost of a biodiesel bus. The Act also allows a 90 percent... transit systems or roadways. iv. Will improve accessibility and transport services for economically...

  16. Strategies to address transition costs in a restructuring electricity industry

    International Nuclear Information System (INIS)

    Baxter, Lester; Hirst, Eric; Hadley, Stanton

    1997-01-01

    This paper discusses the potential financial consequences, or transition costs, of transforming electricity generation from a regulated to a competitive market in the US. Industry-wide estimates suggest potential monetary losses could exceed $100 billion as a result of the move to competition. The paper discusses the most prominent strategies suggested to address these potential losses. For each strategy, the paper identifies the parties most likely to bear the financial consequences. Most strategies do nothing to reduce the total costs to society, but instead shift costs from one set of economic actors to another. The exceptions are those strategies that result in economic-efficiency gains, which can then be used to offset the transition costs. Most of the strategies examined require the cooperation of several parties, including regulators, to be implemented successfully. (author)

  17. Assessing Sustainability Transition in the US Electrical Power System

    Directory of Open Access Journals (Sweden)

    Stephen McCauley

    2010-02-01

    Full Text Available This paper examines sustainability transition dynamics in the US electricity system, drawing on the socio-technical systems approach. We view system change as unfolding along several critical dimensions and geographical scales, including dynamics in the environment, science, civil society, discourse, and state regulatory institutions, as well as in capital and technology formations. A particular emphasis is given to the interaction of discourses, policy networks, and institutions. We trace four distinct regimes which have characterized the evolution of this discourse-network-institutional nexus over the last century. The research examines dynamics that present a challenge to the incumbent energy regime based on fossil fuels, nuclear and hydropower, and demonstrates how the actor-network supporting renewables and energy efficiency has grown stronger and more capable of moving toward a sustainability transition than at any time since the sustainable energy movement began a generation ago.

  18. Electric monopole transitions from low energy excitations in nuclei

    CERN Document Server

    Wood, J L; De Coster, C; Heyde, Kris L G

    1999-01-01

    Electric monopole (E0) properties are studied across the entire nuclear mass surface. Besides an introductory discussion of various model results (shell model, geometric vibrational and rotational models, algebraic models), we point out that many of the largest E0 transition strengths, $\\rho^2$(E0), are associated with shape mixing. We discuss in detail the manifestation of E0 transitions and present extensive data for~: single-closed shell nuclei, vibrational nuclei, well-deformed nuclei, nuclei that exhibit sudden ground-state changes, and nuclei that exhibit shape coexistence and intruder states. We also give attention to light nuclei, odd-A nuclei, and illustrate a suggested relation between $\\rho^2$(E0) and isotopic shifts.

  19. Lost in transition? Comparing strategies of electricity companies in Delhi

    International Nuclear Information System (INIS)

    Criqui, Laure; Zérah, Marie-Hélène

    2015-01-01

    This paper examines the notion of energy transition when implemented by private utilities. In 2000, the Delhi government privatized electricity distribution to three private distribution companies. Most research was concerned with the impact of privatization on energy reliability, tariff settings and regulation issues. This paper looks at two under-researched themes: the expansion of services to poorer neighborhoods and the rollout of clean energy policies. This focus allows to unpack the materiality of socio-technical systems, to analyze how energy infrastructures are being technically deployed on the ground and to identify which social approach is used. To detail the specific practices of each company provides a more nuanced and accurate understanding of the reform. In-depth analysis of the three private utilities show that they interpret the reform mandate differently: they use a varied range of technical tools; they respond differently to social concerns in poorer neighborhoods; and they have distinctive internal management choices and corporate cultures. All these four factors can strengthen or undermine the transition towards increased access and clean energy. - Highlights: • Energy transition in an emerging cities aims at balancing environmental and social concerns. • Utilities have distinct transition paths despite similar privatization and regulation framework. • Utilities paths depend on spatial, social, managerial and corporate considerations. • Utilities' strategies are shaped by urban challenges rather than by energy policies

  20. Transition pathways for a UK low carbon electricity future

    International Nuclear Information System (INIS)

    Foxon, Timothy J.

    2013-01-01

    Achieving long-term targets for greenhouse gas emissions reductions, such as the UK's legally-binding target of reducing its emissions by 80% by 2050, will require a transition in systems for meeting and shaping energy service demands, involving radical substitution to low-carbon supply technologies and improvements in end-use energy efficiency. This paper describes the development and high-level analysis of a set of transition pathways to a UK low carbon electricity system, explaining key features of the core pathways developed and the distinctiveness and value of the approach. The pathways use an ‘action space’ concept to explore the dynamic interactions between choices made by actors, which are influenced by the competing governance ‘framings’ or ‘logics’ that different actors pursue. The paper sets out three core transition pathways – Market Rules, Central Co-ordination and Thousand Flowers, in which market, government and civil society logics respectively dominate. It summarises the key technological and institutional changes in these pathways, and the roles of actors in bringing these about. This leads to an identification of the key risks to the realisation of each of the pathways, and of the challenges for individuals, businesses, social movements and policy-makers in taking action to bring them about and sustain them. - Highlights: ► Development of a set of transition pathways to a UK low carbon electricity system. ► Action space to explore the dynamic interactions between choices made by actors. ► Three core pathways in which market, government and civil society logics dominate. ► Key technological and institutional changes, and the roles of actors in pathways. ► Challenges for different actors in realising pathways.

  1. Challenges to China's transition to a low carbon electricity system

    International Nuclear Information System (INIS)

    Kahrl, Fredrich; Williams, Jim; Ding Jianhua; Hu Junfeng

    2011-01-01

    We examine the challenges to China's transition to a low carbon electricity system, in which renewable energy would play a significant role. China's electricity system currently lacks the flexibility in planning, operations, and pricing to respond to conflicting pressures from demand growth, rising costs, and environmental mandates in a way that simultaneously maintains reliability, decarbonizes the system, and keeps prices within acceptable bounds. Greater flexibility crucially requires the ability to more systematically and transparently manage and allocate costs. This will require re-orientating sector institutions still rooted in central planning, and strengthening independent regulation. Some of the necessary changes require fundamental political and legal reforms beyond the scope of energy policy. However, the system's flexibility can still be increased through the development of traditional planning and regulatory tools and approaches, such as an avoided cost basis for energy efficiency investments, more integrated planning to improve the coordination of generation, transmission, and demand-side investments, and a transparent ratemaking process. The judicious application of OECD electricity sector experience and skills can support these developments. - Research highlights: → China's electricity system currently lacks the flexibility to integrate renewables and reduce CO 2 emissions on a large scale at an acceptable cost and level of reliability. → The challenges to increased flexibility are more institutional than technological. → Chinese government agencies need new approaches to basic power system planning and ratemaking. → OECD countries can help address these challenges through the transfer of 'soft' technologies.

  2. Shifting Control Algorithm for a Single-Axle Parallel Plug-In Hybrid Electric Bus Equipped with EMT

    Directory of Open Access Journals (Sweden)

    Yunyun Yang

    2014-01-01

    Full Text Available Combining the characteristics of motor with fast response speed, an electric-drive automated mechanical transmission (EMT is proposed as a novel type of transmission in this paper. Replacing the friction synchronization shifting of automated manual transmission (AMT in HEVs, the EMT can achieve active synchronization of speed shifting. The dynamic model of a single-axle parallel PHEV equipped with the EMT is built up, and the dynamic properties of the gearshift process are also described. In addition, the control algorithm is developed to improve the shifting quality of the PHEV equipped with the EMT in all its evaluation indexes. The key techniques of changing the driving force gradient in preshifting and shifting compensation phases as well as of predicting the meshing speed in the gear meshing phase are also proposed. Results of simulation, bench test, and real road test demonstrate that the proposed control algorithm can reduce the gearshift jerk and the power interruption time noticeably.

  3. FTA fuel cell bus program : research accomplishments through 2011.

    Science.gov (United States)

    2012-03-01

    Prepared by the Federal Transit Administration (FTA) Office of Research, Demonstration, and Innovation (TRI), this report summarizes the accomplishments of fuel-cell-transit-bus-related research and demonstrations projects supported by FTA through 20...

  4. Lifetime of electric flux tubes near the QCD phase transition

    International Nuclear Information System (INIS)

    Faroughy, Cyrus; Shuryak, Edward

    2010-01-01

    Electric flux tubes are a well-known attribute of the quantum chromodynamic (QCD) vacuum in which they manifest confinement of electric color charges. Recently, experimental results appeared which suggest that not only do those objects persist at temperatures T≅T c near the QCD phase transitions, but their decay is suppressed and the resulting clusters in Au-Au collisions are larger than in pp collisions (i.e., in vacuum). This correlates well with recent theoretical scenarios that view the QCD matter in the T≅T c region as a dual-magnetic plasma dominated by color-magnetic monopoles. In this view, the flux tubes are stabilized by dual-magnetic currents and are described by dual magnetohydrodynamics (DMHD). In this article, we calculate classically the dissipative effects in the flux tube. Such effects are associated with rescattering and finite conductivity of the matter. We derive the DMHD solution in the presence of dissipation and then estimate the lifetime of the electric flux tubes. The conclusion of this study is that a classical treatment leads to too short of a lifetime for the flux tubes.

  5. Electric transition(s) - What Europe and markets have been unable to tell you

    International Nuclear Information System (INIS)

    Hansen, Jean-Pierre; Percebois, Jacques; Mestrallet, Gerard

    2017-01-01

    In an interview, one of the authors proposes an assessment of 20 years of liberalisation of the electric power sector and market: no technological innovation like in the telecommunication sector, disturbance of market operation, high subsidies awarded to renewable sources, emergence of stranded costs. He also explains that electricity is not a product like others (it is a strategic product), the importance of time (a power plant lifetime is often more than 40 years), and that the digital revolution will probably change the deal. He explains why France is an exception in the production of clean electric power. As 40 per cent of power production is based on coal, he discusses what could be an efficient measure to reduce this share. Then, an article proposes a review of the book. It outlines the contradiction between approach by or for the market, reports the different failures noticed by the author regarding power markets and utilities. It describes how the authors promote deregulation and prefer Hayek to Keynes. It finally discusses the two electric transitions which are existing within the European electric power system: the end of public services and the de-carbonation of power generation

  6. Multiple electrical phase transitions in Al substituted barium hexaferrite

    Science.gov (United States)

    Kumar, Sunil; Supriya, Sweety; Kar, Manoranjan

    2017-12-01

    Barium hexaferrite is known to be a very good ferromagnetic material. However, it shows very good dielectric properties, i.e., the dielectric constant is comparable to that of the ferroelectric material. However, its crystal symmetry does not allow it to be a ferroelectric material. Hence, the electrical properties have revived the considerable research interest on these materials, not only for academic interest, but also for technological applications. There are a few reports on temperature dependent dielectric behavior of these materials. However, the exact cause of dielectric as well as electrical conductivity is yet to be established. Hence, Al (very good conducting material) substituted barium hexaferrite (BaFe12-xAlxO19, x = 0.0-4.0) has been prepared by following the modified sol-gel method to understand the ac and DC electrical properties of these materials. The crystal structure and parameters have been studied by employing the XRD and FTIR techniques. There are two transition temperatures, which have been observed in the temperature dependent ac dielectric and DC resistivity measurement. The response of dielectric behaviors to temperature is similar to that of the ferroelectric material; however, the dielectric polarization is due to the polaron hopping, which is evident from the DC resistivity analysis. Hence, the present observations lead to understand the electrical properties of barium hexaferrite. The frequency dependent dielectric dispersion can be understood by the modified Debye model. More interestingly, the dielectric constant decreases and DC resistivity increases with the increase in the Al concentration, which has the correlation between bond length modifications in the crystal due to substitution.

  7. Challenges and Experiences with Electric Propulsion Transit Buses in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Gifford, M.

    2003-11-01

    Document provides background for transit agencies and fleets that are considering electric propulsion technologies. It tells them what to expect and plan for when implementing vehicles with electric propulsion systems.

  8. Estimating bus passenger waiting times from incomplete bus arrivals data

    OpenAIRE

    McLeod, F.N.

    2007-01-01

    This paper considers the problem of estimating bus passenger waiting times at bus stops using incomplete bus arrivals data. This is of importance to bus operators and regulators as passenger waiting time is a key performance measure. Average waiting times are usually estimated from bus headways, that is, time gaps between buses. It is both time-consuming and expensive to measure bus arrival times manually so methods using automatic vehicle location systems are attractive; however, these syste...

  9. Electromagnetic moments and electric dipole transitions in carbon isotopes

    International Nuclear Information System (INIS)

    Suzuki, Toshio; Sagawa, Hiroyuki; Hagino, Kouichi

    2003-01-01

    We carry out shell model calculations to study electromagnetic moments and electric dipole transitions of C isotopes. We point out the configuration dependence of the quadrupole and magnetic moments of the odd C isotopes, which will be useful to find out the deformations and the spin parities of the ground states of these nuclei. We also study the electric dipole states of C isotopes, focusing on the interplay between low energy pigmy strength and giant dipole resonances. As far as the energies of the resonances are concerned, reasonable agreement is obtained with available experimental data for the photoreaction cross sections in 12 C, 13 C, and 14 C, both in the low energy region below (ℎ/2π)ω=14 MeV and in the high energy giant resonance region (14 MeV 15 C is found to exhaust about 12-16 % of the classical Thomas-Reiche-Kuhn sum rule value and 50-80 % of the cluster sum rule value

  10. Electricity reform in developing and transition countries: A reappraisal

    International Nuclear Information System (INIS)

    Williams, J.H.; Ghanadan, R.

    2006-01-01

    Since about 1990, many developing and transition countries have undertaken market-oriented reforms in their electric power sectors. Despite the widespread adoption of a standard policy model, reform processes and outcomes have often failed to meet expectations. Drawing on an extensive literature review and case studies in Asia, Africa, Latin America, and Eastern Europe, this paper describes common features of non-OECD electricity reform and reappraises reform policies and underlying assumptions. Comparison with the sector-focused policy goals of deregulation in OECD countries highlights the importance of national fiscal crises, macroeconomic reforms, and persuasion by multilateral lenders in shaping non-OECD reforms. It also makes clear reform's dependence on attracting foreign capital, and consequent vulnerability to volatile international financial conditions. Case studies of Bolivia, Ghana, India, Poland, and Thailand illustrate reform's diverse pathways and problems in different settings. A broad range of non-OECD reform experiences indicates that disappointing results have often resulted from a narrow focus on finance and cost recovery, inflexibly applied. The paper concludes that improving reform will require emphasizing a broader set of objectives, including service provision, public benefits, effective regulation, and social/political legitimacy. Above all, reforms must be based on realistic assessments of national needs and capabilities. (author)

  11. Phase transition and electrical properties of strontium orthovanadate

    International Nuclear Information System (INIS)

    Pati, Biswajit; Choudhary, R.N.P.; Das, Piyush R.

    2013-01-01

    Highlights: •Highly crystallized Sr 3 V 2 O 8 ceramic has a structural and micro-structural stability. •The low values of ε r and tan δ make this material useful for microwave applications. •The material exhibits good ferroelectric properties suitable for memory devices. •The dielectric relaxation is of non Debye-type and ac conductivity obeys Jonscher power law. •The small value of dc activation energy suggests the conduction initiates with a small energy. -- Abstract: The current research work reports the study of phase transition and transport mechanism in lead-free strontium orthovanadate (Sr 3 V 2 O 8 ), prepared using a high-temperature solid-state reaction technique. Preliminary X-rays diffraction studies exhibit the formation of a single-phase compound in the trigonal crystal system. Study of microstructure of gold-coated pellet by scanning electron microscopy (SEM) shows well-defined and homogeneous grains in the morphology. Detailed studies of dielectric parameters (ε r and tan δ) of the compound as a function of temperature at some selected frequencies reveal their independence for a wide range of temperatures. An anomaly in relative permittivity (ε r ) suggests the existence of a ferroelectric–paraelectric phase transition of diffuse-type in the material that confirms through the detailed studies of its electric polarization. Detailed studies of impedance and related parameters exhibit that the electrical properties of the material are strongly dependent on temperature, and bear a good correlation with its microstructure (i.e., bulk, grain boundary, etc.). The decrease in value of bulk resistance on increasing temperature suggests the negative temperature co-efficient of resistance (NTCR) behavior of the material. Studies of electric modulus indicate the presence of hopping conduction mechanism in the system with non-exponential type of conductivity relaxation. The nature of variation of dc conductivity with temperature confirms the

  12. Electrical and Magnetic Properties of Binary Amorphous Transition Metal Alloys.

    Science.gov (United States)

    Liou, Sy-Hwang

    The electrical, superconductive and magnetic properties of several binary transition metal amorphous and metastable crystalline alloys, Fe(,x)Ti(,100-x) (30 (LESSTHEQ) x (LESSTHEQ) 100), Fe(,x)Zr(,100-x) (20 (LESSTHEQ) x (LESSTHEQ) 93), Fe(,x)Hf(,100-x) (20 (LESSTHEQ) x (LESSTHEQ) 100), Fe(,x)Nb(,100 -x) (22 (LESSTHEQ) x (LESSTHEQ) 85), Ni(,x)Nb(,100-x) (20 (LESSTHEQ) x (LESSTHEQ) 80), Cu(,x)Nb(,100-x) (10 (LESSTHEQ) x (LESSTHEQ) 90) were studied over a wide composition range. Films were made using a magnetron sputtering system, and the structure of the films was investigated by energy dispersive x-ray diffraction. The composition region of each amorphous alloys system was determined and found in good agreement with a model proposed by Egami and Waseda. The magnetic properties and hyperfine interactions in the films were investigated using a conventional Mossbauer spectrometer and a ('57)Co in Rh matrix source. In all Fe-early transition metal binary alloys systems, Fe does not retain its moment in the low iron concentration region and the result is that the critical concentration for magnetic order (x(,c)) is much larger than anticipated from percolation considerations. A direct comparison between crystalline alloys and their amorphous counterparts of the same composition illustrate no clear correlation between crystalline and amorphous states. Pronounced discontinuities in the magnetic properties with variation in Fe content of all Fe-early transition metal alloys at phase boundaries separating amorphous and crystalline states have been observed. This is caused by the differences in the atomic arrangement and the electronic structure between crystalline and amorphous solids. The temperature dependence of resistivity, (rho)(T), of several binary amorphous alloys of Fe-TM (where TM = Ti, Zr, Hf, Nb etc.) has been studied from 2K to 300K. The Fe-poor (x x(,c)) samples have distinctive differences in (rho)(T) at low temperature (below 30K). All the magnetic samples

  13. Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors

    Science.gov (United States)

    Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki

    2018-01-01

    For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) (referred to as “sensor platform LSI”) for bus-networked Micro-Electro-Mechanical-Systems (MEMS)-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB) in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI) was 73.66 Hz. PMID:29342923

  14. Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors

    Directory of Open Access Journals (Sweden)

    Chenzhong Shao

    2018-01-01

    Full Text Available For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS Large-Scale Integration (LSI (referred to as “sensor platform LSI” for bus-networked Micro-Electro-Mechanical-Systems (MEMS-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI was 73.66 Hz.

  15. TPG bus passes

    CERN Multimedia

    Staff Association

    2013-01-01

    The CERN Staff Association will stop selling TPG bus passes. All active and retired members of the CERN personnel will be able to purchase Unireso bus passes from the CERN Hostel - Building 39 (Meyrin site) from 1st February 2013. For more information: https://cds.cern.ch/journal/CERNBulletin/2013/04/Announcements/1505279?ln=en

  16. Connecticut nutmeg fuel cell bus project : first analysis report.

    Science.gov (United States)

    2012-07-01

    This report summarizes the experience and early results from a fuel cell bus demonstration funded by the Federal Transit Administra-tion (FTA) under the National Fuel Cell Bus Program (NFCBP). A team led by the Northeast Advanced Vehicle Consortium a...

  17. Electrical system architecture

    Science.gov (United States)

    Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Akasam, Sivaprasad [Peoria, IL; Hoff, Brian D [East Peoria, IL

    2008-07-15

    An electrical system for a vehicle includes a first power source generating a first voltage level, the first power source being in electrical communication with a first bus. A second power source generates a second voltage level greater than the first voltage level, the second power source being in electrical communication with a second bus. A starter generator may be configured to provide power to at least one of the first bus and the second bus, and at least one additional power source may be configured to provide power to at least one of the first bus and the second bus. The electrical system also includes at least one power consumer in electrical communication with the first bus and at least one power consumer in electrical communication with the second bus.

  18. Electric Field-Dependent Photoluminescence in Multilayer Transition Metal Dichalcogenides

    Science.gov (United States)

    Stanev, T. K.; Henning, A.; Sangwan, V. K.; Speiser, N.; Stern, N. P.; Lauhon, L. J.; Hersam, M. C.; Wang, K.; Valencia, D.; Charles, J.; Kubis, T. C.

    Owing to interlayer coupling, transition metal dichalcogenides (TMDCs) such as MoS2 exhibit strong layer dependence of optical and electronic phenomena such as the band gap and trion and neutral exciton population dynamics. Here, we systematically measure the effect of layer number on the optical response of multilayer MoS2 in an external electric field, observing field and layer number dependent emission energy and photoluminescence intensity. These effects are studied in few (2-6) and bulk (11 +) layered structures at low temperatures. In MoS2\\ the observed layer dependence arises from several mechanisms, including interlayer charge transfer, band structure, Stark Effect, Fermi level changes, screening, and surface effects, so it can be challenging to isolate how these mechanisms impact the observables. Because it behaves like a stack of weakly interacting monolayers rather than multilayer or bulk, ReS2 provides a comparison to traditional TMDCs to help isolate the underlying physical mechanisms dictating the response of multilayers. This work is supported by the National Science Foundation MRSEC program (DMR-1121262), and the 2-DARE Grant (EFRI-1433510). N.P.S. is an Alfred P. Sloan Research Fellow.

  19. Electric buses - An energy efficient urban transportation means

    Energy Technology Data Exchange (ETDEWEB)

    Kuehne, Reinhart [German Aerospace Center (DLR), Transportation Studies, Rutherfordstr. 2, 12489 Berlin (Germany)

    2010-12-15

    Bus transit systems with electric traction are an important contribution to the post fossil fuel mobility. Most renewable energy sources provide energy in the form of electricity. Electric motors thus have promise in the development of the way ''beyond oil''. The reactivation of trolley bus systems - grid bounded but also catenary free for short distances - paves this way. The design of modern trolley bus operations overcomes the existing disadvantages of conventional buses using fossil fuel. Germany has an efficient industry in this field, that offers braking energy recovery and energy storage in modern supercapacitors as well as technical and organisational innovations for a local emission free and a low noise transit system. Gentle but powerful when starting and braking, the trolley bus is cost effective and easy to integrate into an existing infrastructure. Such an electric bus system is ecological, customer-friendly and suitable for cities. It has a high economic efficiency and it also expands the traffic planning field towards an ecological future technology. This paper shows examples at home and abroad how electric buses achieve an energy solving modern urban traffic. It gives insights into technical developments of electric vehicle equipment, cateneries with fast driving handling characteristics and the use of plain electric and hybrid powertrains. (author)

  20. Industry evolution, rational agents and the transition to sustainable electricity production

    NARCIS (Netherlands)

    Safarzynska, K.E.; van den Bergh, J.C.J.M.

    2011-01-01

    Guiding a transition to low carbon electricity requires a good understanding of the substitution of old by new technologies in the electricity industry. With the aim of explaining historical change from coal to gas in the British electricity industry, we develop a formal model of technological

  1. Electric field bifurcation and transition in the core plasma of CHS

    International Nuclear Information System (INIS)

    Fujisawa, A.; Iguchi, H.; Sanuki, H.; Itoh, K.; Okamura, S.; Matsuoka, K.; Hamada, Y.; Itoh, S.-I.

    1997-01-01

    In the CHS heliotron/torsatron, dynamic phenomena associated with transitions in radial electric field were observed during combined ECH+NBI heated plasmas. The observations with high temporal resolution confirmed a nonlinear relation between radial electric field and radial current to cause these phenomena associated with electric field bifurcation. (author)

  2. Southwest Direct Express Bus Demonstration in Orlando, FL

    Science.gov (United States)

    1988-04-01

    In August 1983, the Orange-Seminole-Osceola Transit Authority (OSOTA) initiated six express bus routes in the southwest corridor of Orlando (known collectively as the Southwest Direct) as an UMTA-funded demonstration project. While one objective of t...

  3. The US Electricity Industry and the Low-Carbon Transition

    International Nuclear Information System (INIS)

    Mathieu, Carole

    2016-04-01

    While the wave of liberalisation produced a fragmented, but now stabilised, industrial landscape, the US power sector is about to undergo another major transformation with the low-carbon transition. Against a background of combined weak demand for electricity, a boom in distributed solar PV power and a decline in the profitability of merchant assets, incumbent stakeholders are currently dealing with further questions about the future of their business models. Driven as much by market forces as by government support mechanisms, these destabilising factors have an impact, which is still difficult to assess, but the need to control future transformation is already at the heart of debate. In areas where output is priced on the wholesale markets, new tools are being studied to secure compensation for some power stations, with the issue of possible excessive dependency on natural gas in the background. At the same time, an increasing number of states are questioning the design of their support mechanisms for distributed energy. If net metering, the main support mechanism for distributed solar PV power, has been a resounding success because of its simplicity, it is now criticised because of the problems of covering grid costs and the cross-subsidies it leads to. Although reforms are always difficult to implement, since they involve a conflict of increasingly organised interests, consensus is beginning to emerge regarding the structure of retail sales tariffs. Nevertheless, calls for an assessment of distributed generation according to its actual value for the system are increasing, without any real convergence of views on the methodology to be adopted to date. Conventional stakeholders are also looking to adapt in order to find growth opportunities where primarily only challenges appear. The diversification of activities is an important lever for transformation, even if the case of NRG Energy illustrates the difficulty in making strategic shifts while maintaining

  4. The erigone bus study

    International Nuclear Information System (INIS)

    Durieu, L.; Vignes, M.; Wolstenholme, P.

    1982-01-01

    A study has been made of some factors determining the performance and cost-effectiveness of microcomputer bus systems implemented in Europa crates. An experimental system has been specified and a number of modules constructed in accordance with the specification, in order to test the validity of some of the ideas proposed. It has been demonstrated that the bus interfacing logic can be simple and inexpensive, while maintaining a high degree of processor independence and also a high degree of transparency in operation. The number of pins required by the bus is minimized by multiplexing address and data. A series termination for the drive of the multiplexed lines permits cross-talk to be reduced to insignificant levels: this technique is recommended for wider application. The experimental bus is proposed as a basis for the construction of simple microcomputer-based instrumentation systems. (orig.)

  5. Creative Bus Financing.

    Science.gov (United States)

    Malone, Wade

    1982-01-01

    Alternative ways of financing school bus purchases include financing privately through contractors or commercial banks, financing through sources such as insurance companies and pension funds, leasing the buses, or contracting for transportation services. (Author/MLF)

  6. Design and Manufacture of the Superconducting Bus-bars for the LHC Main Magnets

    CERN Document Server

    Belova, L M; Perinet-Marquet, J L; Ivanov, P; Urpin, C

    2002-01-01

    The main magnets of the LHC are series-connected electrically in different powering circuits by means of superconducting bus-bars, carrying a maximum current of 13 kA. These superconducting bus-bars consist of a superconducting cable thermally and electrically coupled to a copper profile all along the length. The function of the copper profile is essentially to provide an alternative path for the current in case the superconducting cable loses its superconducting state and returns to normal state because of a transient disturbance or of a normal zone propagation coming from the neighbouring magnets. When a superconducting bus-bar quenches to normal state its temperature must always stay below a safe values of about 100°C while the copper is conducting. When a resistive transition is detected, the protection systems triggers the ramping down of the current from 13000 A to 0. The ramp rate must not exceed a maximum value to avoid the transition of magnets series-connected in the circuit. This paper concerns th...

  7. SPFC bus design studies

    Energy Technology Data Exchange (ETDEWEB)

    Potter, L.; Reinkingh, J.

    1999-07-01

    This report presents the results of a study assessing the design options for a solid polymer fuel cell bus. Commercial and operation requirements, environmental and market drivers, and fuel processor modeling are examined. Power train specifications and detailed system design are investigated covering fuel cell system dynamic response, hybrid system size, fuel cell system start-up time, system specifications, and hybrid bus component dimensions and costs. (UK)

  8. LHC on the bus

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    On 15 December, an airport bus will be transformed in the image of CERN. The bus will be seen by the thousands of travellers arriving in Geneva, informing them of the possibility to visit CERN.   Sketch of the bus. The good relationship between Geneva International Airport and CERN started several years ago. In 2004 the airport put advertising space in the arrivals area at CERN's disposal free of charge. Now, starting on 15 December, a 40-foot long bus will display a giant sticker advertisement depicting CERN as it takes passengers over the airport tarmac to their planes. This is no ordinary sticker, and it was no mean task to attach it to the bus. The task of producing and attaching it was entrusted to Geneva-based specialists Mathys SA. With the ski season opening on 15 December, there will be many travellers arriving at the airport, and the bus will be ready to receive them. When one thinks of CERN, the subjects that naturally come to mind are the LHC, the mysteries of the Universe...

  9. PyBus -- A Python Software Bus

    OpenAIRE

    Lavrijsen, W

    2005-01-01

    A software bus, just like its hardware equivalent, allows for the discovery, installation, configuration, loading, unloading, and run-time replacement of software components, as well as channeling of inter-component communication. Python, a popular open-source programming language, encourages a modular design on software written in it, but it offers little or no component functionality. However, the language and its interpreter provide sufficient hooks to implement a thin, integral layer...

  10. Electrifying Australian transport: Hybrid life cycle analysis of a transition to electric light-duty vehicles and renewable electricity

    International Nuclear Information System (INIS)

    Wolfram, Paul; Wiedmann, Thomas

    2017-01-01

    Highlights: •This research assesses life-cycle carbon impacts of different powertrains. •We illustrate a transition to low-carbon vehicles in a hybrid IO-LCA model. •Different electricity and transport scenarios are integrated in the model. •With Australia’s current grid-mix, electric vehicles offer no mitigation potential. •Using renewable energy, electric vehicle carbon footprints can be cut by 66%. -- Abstract: Recent life cycle assessments confirmed the greenhouse gas emission reduction potential of renewable electricity and electric vehicle technologies. However, each technology is usually assessed separately and not within a consistent macro-economic, multi-sectoral framework. Here we present a multi-regional input-output based hybrid approach with integrated scenarios to facilitate the carbon footprint assessment of all direct and indirect effects of a transition to low-emission transportation and electricity generation technologies in Australia. The work takes into account on-road energy consumption values that are more realistic than official drive-cycle energy consumption figures used in previous work. Accounting for these factors as well as for Australia’s grid electricity, which heavily relies on coal power, electric vehicles are found to have a higher carbon footprint than conventional vehicles, whereas hybrid electric vehicles have the lowest. This means that – from a carbon footprint perspective – powertrain electrification is beneficial only to a certain degree at the current stage. This situation can be changed by increasing shares of renewable electricity in the grid. In our best-case scenario, where renewable energy accounts for 96% of the electricity mix in 2050, electric vehicle carbon footprints can be cut by 66% by 2050 relative to 2009. In the business-as-usual scenario (36% renewable electricity share by 2050), electric vehicles can reach a 56% reduction if fossil fuel power plants significantly increase their efficiencies

  11. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2013

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gikakis, Christina [Federal Transit Administration, Washington, DC (United States)

    2013-12-01

    This report is the seventh in an annual series of reports that summarize the progress of fuel cell electric bus (FCEB) development in the United States and discuss the achievements and challenges of introducing fuel cell propulsion in transit. The report also provides a snapshot of current FCEB performance results from August 2012 through July 2013 for five FCEB demonstrations at four transit agencies.

  12. Electric Monopole Transition Strengths in the Stable Nickel Isotopes

    Science.gov (United States)

    Evitts, Lee John

    A series of measurements of stable nickel isotopes were performed at the Australian National University in Canberra. Excited states in 58,60,62Ni were populated via inelastic scattering of proton beams delivered by the 14UD Pelletron accelerator. Multiple setups were used in order to determine the structure of low-lying states. The CAESAR array of Compton-suppressed HPGe detectors was used to measure the (E2/M1) mixing ratio of transitions from angular distributions of gamma rays. The Super-e spectrometer was used to measure conversion coefficients for a number of J to J transitions. The data obtained from both devices was combined with previously measured parent lifetimes and branching ratios to determine E0 transition strengths between J-pi transitions. The E0 transition strength for the second 0+ to first 0+ transitions in 60,62Ni have been measured for the first time through internal conversion electron detection. The experimental value of 132(+59,-70) for 62Ni agrees within 2 sigma of the previous result obtained from internal pair formation. However it is likely that the previous experimental results used an outdated theoretical model for internal pair formation emission. This work also represents the first measurements of E0 transition strengths between 2+ states in Ni isotopes. There is generally large E0 strength between the 2+ states, particularly in the second 2+ to first 2+ transition, however there is also a large uncertainty in the measurements owing to the difficulties involved in measuring conversion coefficients. In 62Ni, the E0 transition strength of 172(+62,-77) for the second 2+ to first 2+ transition gives further weight to the argument against the spherical vibrator model, as an E0 transition is forbidden if there is a change of only one phonon. The large measurement also indicates the presence of shape coexistence, complementing the recent experimental work carried out in the neutron-rich Ni isotopes.

  13. 交通拥堵条件下的公交发车间隔过渡模型研究%A Bus Departure Time Interval Transition Model Considering Traffic Congestion

    Institute of Scientific and Technical Information of China (English)

    董红召; 孔娟娟; 刘晴辉

    2016-01-01

    The existing planning models of bus departure time interval usually ignored the important impact factor of real-time traffic congestion. To solve the issue, a departure time interval transition method is presented considering passenger travel demand and traffic congestion. The bus operating hours is divided into several temporary periods separately according to the passenger travel demand and the congestion conditions by the clustering method of samples with sequence. Then these temporary periods are combined to form a period set, in which each period possess the features including passenger travel flow and traffic congestion. Consequently, the departure interval transition model is established to adjust the transient time separately between two neighbor periods to match the passenger travel demand and departure plan. Finally a practical experiment for one bus route in Hangzhou is implemented to verify the proposed model by PARAMICS simulation. The result shows that the model can keep the load ratio in the range of 40%to 70%with the precondition of satisfying the passenger travel demand, and help to improve the service level and the efficiency of the bus transit system.%针对现有公交发车间隔模型忽略了交通拥堵状态对公交运营影响的问题,提出了交通拥堵条件下响应客流需求的发车间隔设计方法。采用有序样本聚类方法,分别根据客流需求及交通拥堵状态对时间段进行聚类划分,并融合处理为若干具有不同客流与拥堵状态综合特征的时间段;分析相邻时段综合特征关系,建立了发车间隔的过渡模型,该模型确定发车时段之间的衔接时长,通过调整衔接时间长度将发车序列在时间轴上平移,弥补交通拥堵造成的客流需求与发车计划匹配错位。最后采用杭州市某线路的运营数据对该模型进行了分析验证,PARAMICS交通仿真实验表明,该模型在满足客流需求的前提下使

  14. Radiative Decay Rates for Electric Dipole, Magnetic Dipole and Electric Quadrupole Transitions in Triply Ionized Thulium (Tm IV

    Directory of Open Access Journals (Sweden)

    Saturnin Enzonga Yoca

    2017-09-01

    Full Text Available A new set of radiative decay parameters (oscillator strengths, transition probabilities for spectral lines in triply ionized thulium (Tm IV has been obtained within the framework of the pseudo-relativistic Hartree-Fock (HFR approach. The effects of configuration interaction and core-polarization have been investigated in detail and the quality of the results has been assessed through a comparison between different HFR physical models. The spectroscopic data listed in the present paper cover electric dipole as well as magnetic dipole and electric quadrupole transitions in a wide range of wavelengths from extreme ultraviolet to near infrared.

  15. Cost Effectiveness Analysis of Quasi-In-Motion Wireless Power Transfer for Plug-In Hybrid Electric Transit Buses from Fleet Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijuan; Gonder, Jeff; Brooker, Aaron; Meintz, Andrew; Konan, Arnaud; Markel, Tony

    2016-05-16

    This study evaluated the costs and benefits associated with the use of stationary-wireless-power-transfer-enabled plug-in hybrid electric buses and determined the cost effectiveness relative to conventional buses and hybrid electric buses. A factorial design was performed over a number of different battery sizes, charging power levels, and f bus stop charging stations. The net present costs were calculated for each vehicle design and provided the basis for design evaluation. In all cases, given the assumed economic conditions, the conventional bus achieved the lowest net present cost while the optimal plug-in hybrid electric bus scenario beat out the hybrid electric comparison scenario. The parameter sensitivity was also investigated under favorable and unfavorable market penetration assumptions.

  16. Reversible temperature regulation of electrical and thermal conductivity using liquid–solid phase transitions

    Science.gov (United States)

    Zheng, Ruiting; Gao, Jinwei; Wang, Jianjian; Chen, Gang

    2011-01-01

    Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions. PMID:21505445

  17. Reversible temperature regulation of electrical and thermal conductivity using liquid-solid phase transitions.

    Science.gov (United States)

    Zheng, Ruiting; Gao, Jinwei; Wang, Jianjian; Chen, Gang

    2011-01-01

    Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions.

  18. Research on the Coordinated Design of Bus and Taxi Station

    Directory of Open Access Journals (Sweden)

    Jiangfeng Xi

    2015-01-01

    Full Text Available Rises in the number of transit buses, bus routes, and overall traffic volume in China’s cities, coupled with interference from other transport modes, such as taxis loading and unloading passengers nearby, have led to increasing traffic delays at bus stops, which is considered one of the factors degrading service levels and traffic operations on urban roadways. This paper studies traffic characteristics at bus stops, investigates variations in delay from different types or designs of bus stops, and analyzes the impact of it on traffic capacity, the purpose of which is to propose a solution to predicting the feasibility of an integrated design of bus stops and taxi stands with the help of mathematical models and based on the objectives of optimal traffic operations and passenger transfer.

  19. 电动执行机构总线控制器在广西石化的应用%The application of electric actuator bus controller in Guangxi Petrochemical Company

    Institute of Scientific and Technical Information of China (English)

    贾舒晨

    2013-01-01

    本文通过对ROTORK电动执行机构总线控制器与横河DCS之间串口通讯的具体实现方法的分析,结合实际工作中存在的问题,详细描述了基于串口通讯协议的冗余控制方式及组态方案。ROTORK总线控制器在广西石化储运罐区的的使用中,运行良好。%Based on analyzing the concrete realization method of serial communication between ROTORK electric actuator controller and DCS of Yokogawa, combined with the existing problems of actual implement, this paper describes the detailed redundant control method and configuration scheme based on serial communication protocol. And can approve that ROTORK bus control er runs wel in the operation of Guangxi petrochemical storage tank.

  20. Reliability risks during the transition to competitive electricity markets

    International Nuclear Information System (INIS)

    Hughes, J.P.

    2005-01-01

    The Electricity Consumers Resource Council (ELCON) is a U.S. association representing industrial consumers of electricity, and is a long-standing advocate of competition in the electric power industry. However, because a reliable grid is necessary to support competitive wholesale markets, ELCON believes that the transmission system is an essential facility that must remain regulated. The initiatives discussed in this white paper represent significant steps that the National Electric Reliability Council (NERC) and the industry have taken to improve reliability in a competitive and restructured electric industry. Strategic manoeuvres of incumbent utilities to maintain market share were evaluated, as well as discrimination against potential competitors. It was suggested that, occasionally, indecisive federal policies have been taken advantage of by utilities. The unintended consequences of state restructuring policies that allow utilities to over-earn their revenue requirements were reviewed. NERC reliability standards will remain unenforceable until a new Electricity Reliability Organization has been certified. Flawed market designs and inadequate market power mitigation, as well as the financial distress of merchant generators, pose considerable risks. It was suggested that these risks could trigger transmission loading relief incidents, local outages or widespread outages. In the absence of mandatory reliability standards with penalties, and complementary market rules for mitigating generation and transmission market power, economic incentives will encourage other forms of opportunistic behavior that may be the root cause of other outages. Public concern regarding these risks to grid reliability may result in lost public support for competitive electricity markets. Proposed solutions include the certification of a new Electric Reliability Organization to establish and enforce mandatory reliability standards, and granting the Federal Energy Regulatory Commission

  1. Fast electric dipole transitions in Ra-Ac nuclei

    International Nuclear Information System (INIS)

    Ahmad, I.

    1985-01-01

    Lifetime of levels in 225 Ra, 225 Ac, and 227 Ac have been measured by delayed coincidence techniques and these have been used to determine the E1 gamma-ray transition probabilities. The reduced E1 transition probabilities. The reduced E1 transition probabilities in 225 Ra and 225 Ac are about two orders of magnitude larger than the values in mid-actinide nuclei. On the other hand, the E1 rate in 227 Ac is similar to those measured in heavier actinides. Previous studies suggest the presence of octupole deformation in all the three nuclei. The present investigation indicates that fast E1 transitions occur for nuclei with octupole deformation. However, the studies also show that there is no one-to-one correspondence between E1 rate and octupole deformation. 13 refs., 4 figs

  2. Displaced Electric Sail Orbits Design and Transition Trajectory Optimization

    Directory of Open Access Journals (Sweden)

    Naiming Qi

    2014-01-01

    Full Text Available Displaced orbits for spacecraft propelled by electric sails are investigated as an alternative to the use of solar sails. The orbital dynamics of electric sails based spacecraft are studied within a spherical coordinate system, which permits finding the solutions of displaced electric sail orbits and optimize transfer trajectory. Transfer trajectories from Earth's orbit to displaced orbit are also studied in an optimal framework, by using genetic algorithm and Gauss pseudospectral method. The initial guesses for the state and control histories used in the Gauss pseudospectral method are interpolated from the best solution of a genetic algorithm. Numerical simulations show that the electric sail is able to perform the transfer from Earth’s orbit to displaced orbit in acceptable time, and the hybrid optimization method has the capability to search the feasible and optimal solution without any initial value guess.

  3. Electric driving. Evaluation of transitions based on system options

    International Nuclear Information System (INIS)

    Nagelhout, D.; Ros, J.P.M.

    2009-01-01

    Over the past years, electric driving has become more and more attractive because of the development of better batteries. Driving electric vehicles could drastically reduce CO2 emissions, especially if more electricity would be generated by using sustainable energy. As most passenger cars are not used at night, this is the ideal time for charging their batteries. This would be cost-effective because, at that time, there is a surplus of generating capacity, and wind energy could also be used more effectively. Moreover, consumers will be able to drive clean and quiet vehicles at costs that seem surmountable in the future. At least two obstacles still need to be overcome. The first of which is the current maximum range of electric vehicles of around a few hundred kilometres. The second obstacle is the need for a standardised European network of charging stations, and electrical outlets near residences and at commercial and public parking facilities. This report shows the challenges facing the government and the business community of utilising the benefits of electric driving and of overcoming the obstacles [nl

  4. Project survey for trolley-bus transport; Johdinautoliikenteen hankeselvitys

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, T.; Eklund, P.; Airaksinen, S.; Maettoe, R.; Laehdetie, A.

    2011-04-15

    To investigate the feasibility and rationality of the revival of trolley bus traffic in Helsinki a full size project plan was conducted for a variety of alternatives. This included a survey on the latest developments of the trolley bus technology, three optional plans for route network, a budgetary level design for a fully functional depot in Koskela bus depot, examination of urban landscape structures, a study on organisational options, particular technical specifications applicable on suitable trolley buses and an examination of the impacts on the environment and on the future development of public transport. The basic concept of a trolley bus as a means of electric public transport vehicle has found its form over the years, but all the components of the system undergo at present intensive development. In context of this survey also the option of a fully autonomous electric bus powered by accumulators or fuel cells and the like was investigated. However, such technology is still totally inadequate for a heavy duty bus. There are no economically competitive and effective systems available as yet. The trolley bu is the far most reliable system and gives the best life cycle economy for a foreseeable future. Earliest estimates for alternative electric technologies in regular bus service are viable just after one investment cycle some time beyond 2030. Then it should be possible to run without the support of a comprehensive overhead line. The latest achievements in the development of trolley bus are auxiliary engine and accumulator systems allowing for more autonomous propulsion. Nowadays, trolley buses are equipped with an auxiliary power unit that alleviates the traditional restrictions of the overhead line. The modern trolley bus may run short distances without the trolley lines. Recuperation of the kinetic energy at deceleration (braking) either into the overhead line network or by storing it in the vehicle is one of the characteristics of modern trolley buses

  5. Multiple synchronization transitions in scale-free neuronal networks with electrical and chemical hybrid synapses

    International Nuclear Information System (INIS)

    Liu, Chen; Wang, Jiang; Wang, Lin; Yu, Haitao; Deng, Bin; Wei, Xile; Tsang, Kaiming; Chan, Wailok

    2014-01-01

    Highlights: • Synchronization transitions in hybrid scale-free neuronal networks are investigated. • Multiple synchronization transitions can be induced by the time delay. • Effect of synchronization transitions depends on the ratio of the electrical and chemical synapses. • Coupling strength and the density of inter-neuronal links can enhance the synchronization. -- Abstract: The impacts of information transmission delay on the synchronization transitions in scale-free neuronal networks with electrical and chemical hybrid synapses are investigated. Numerical results show that multiple appearances of synchronization regions transitions can be induced by different information transmission delays. With the time delay increasing, the synchronization of neuronal activities can be enhanced or destroyed, irrespective of the probability of chemical synapses in the whole hybrid neuronal network. In particular, for larger probability of electrical synapses, the regions of synchronous activities appear broader with stronger synchronization ability of electrical synapses compared with chemical ones. Moreover, it can be found that increasing the coupling strength can promote synchronization monotonously, playing the similar role of the increasing the probability of the electrical synapses. Interestingly, the structures and parameters of the scale-free neuronal networks, especially the structural evolvement plays a more subtle role in the synchronization transitions. In the network formation process, it is found that every new vertex is attached to the more old vertices already present in the network, the more synchronous activities will be emerge

  6. Learning NServiceBus

    CERN Document Server

    Boike, David

    2013-01-01

    This is a practical tutorial containing hands-on examples for creating a messaging and SOA based service bus.This book is for .NET developers who are looking for ways to overcome problems related to buggy third party web service integrations, codebases that have grown into a big ball of mud, and batch jobs failure.

  7. Positioning Nuclear Power in the Low-Carbon Electricity Transition

    Directory of Open Access Journals (Sweden)

    Aviel Verbruggen

    2017-01-01

    Full Text Available Addressing climate change requires de-carbonizing future energy supplies in an increasingly energy-dependent world. The IEA and the IPCC (2014 mention the following as low-carbon energy supply options: ‘renewable energy, nuclear power and fossil fuels with carbon capture and storage’. Positioning nuclear power in the decarbonization transition is a problematic issue and is overridden by ill-conceived axioms. Before probing these axioms, we provide an overview of five major, postwar energy-related legacies and some insight into who is engaged in nuclear activities. We check whether low-carbon nuclear power passes the full sustainability test and whether it is compatible with the unfettered deployment of variable renewable power sourced from the sun and from wind and water currents, which delivers two negative answers. We show that the best approach of the sustainable energy transition was Germany’s 2011 decision to phase out nuclear power for a fast development and full deployment of renewable power. This is the best approach for the sustainable energy transition. We offer five practical suggestions to strengthen and accelerate carbon- and nuclear-free transitions. They are related to institutional issues like the role of cost-benefit analysis and the mission of the International Atomic Energy Agency, to the costs of nuclear risks and catastrophes, and to the historical record of nuclear technology and business.

  8. Moving EVs (Electric vehicles) into a mass transit scenario

    Energy Technology Data Exchange (ETDEWEB)

    Petrie, D [Petrie Transit Consultants (United States)

    1996-12-31

    In this futuristic scenario electric microcars, providing local mobility, would be automatically loaded onto maglev trucks for longer commutes on a guideway located on a barriered inside lane of existing freeways. Stations are located above the freeway and an elegant Command and Control subsystem would be matched to traffic requirements. (Author)

  9. Will electrical cyber-physical interdependent networks undergo first-order transition under random attacks?

    Science.gov (United States)

    Ji, Xingpei; Wang, Bo; Liu, Dichen; Dong, Zhaoyang; Chen, Guo; Zhu, Zhenshan; Zhu, Xuedong; Wang, Xunting

    2016-10-01

    Whether the realistic electrical cyber-physical interdependent networks will undergo first-order transition under random failures still remains a question. To reflect the reality of Chinese electrical cyber-physical system, the "partial one-to-one correspondence" interdependent networks model is proposed and the connectivity vulnerabilities of three realistic electrical cyber-physical interdependent networks are analyzed. The simulation results show that due to the service demands of power system the topologies of power grid and its cyber network are highly inter-similar which can effectively avoid the first-order transition. By comparing the vulnerability curves between electrical cyber-physical interdependent networks and its single-layer network, we find that complex network theory is still useful in the vulnerability analysis of electrical cyber-physical interdependent networks.

  10. Using restructured electricity markets in the hydrogen transition: The PJM case

    Energy Technology Data Exchange (ETDEWEB)

    Felder, F.A.; Hajos, A. [Rutgers State University, New Brunswick, NJ (United States)

    2006-10-15

    We examine a hydrogen transition strategy of using excess electric generation capacity in the U.S. midatlantic states during off-peak hours to produce hydrogen via electrolysis. Four different generation technologies are evaluated: combined-cycle natural gas, nuclear power, clean coal, and pulverized coal. We construct hydrogen-electricity price curves for each technology and evaluate the resulting air emissions of key pollutants. Substantial capital investments may be avoided by leveraging off generation assets that would otherwise be built to produce electricity. We also account for the interaction between the production of hydrogen and wholesale electricity prices and demand. Results show that off-peak electrolysis is a plausible but not dominant strategy for hydrogen production; however, there may be a substantial real option value in using the electric power system to transition to a hydrogen economy that may exceed the direct cost savings of producing hydrogen by less expensive methods.

  11. Industry evolution, rational agents and the transition to sustainable electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Safarzynska, Karolina, E-mail: ksafarzy@wu.ac.at [Institute for the Environment and Regional Development, WU Vienna University of Economics and Business, Nordbergstrasse 15 (UZA4, 4B), A-1090 Vienna (Austria); Bergh, Jeroen C.J.M. van den, E-mail: jeroen.bergh@uab.es [ICREA, Barcelona (Spain); Institute for Environmental Science and Technology and Department of Economics and Economic History, Universitat Autonoma de Barcelona, Edifici Cn-Campus UAB, 08193 Bellaterra (Spain); Faculty of Economics and Business Administration, and the Institute for Environmental Studies, VU University Amsterdam (Netherlands); Fellow of Tinbergen Institute and NAKE (Netherlands)

    2011-10-15

    Guiding a transition to low carbon electricity requires a good understanding of the substitution of old by new technologies in the electricity industry. With the aim of explaining historical change from coal to gas in the British electricity industry, we develop a formal model of technological change, where energy technologies diffuse through the construction of new power plants. We considered two model versions: with rational and boundedly rational investors. In each model version, we look at the causal relations between price and output setting mechanisms, fuel and labour use, and investment decisions for different institutional arrangements. We quantify model parameters on data for the United Kingdom. We find that the version of the model with rational investors is capable of replicating well core features of UK electricity history. This includes a rapid diffusion of gas in electricity production, the evolution of the average size of newly installed plants, and a high percentage of electricity sales covered by (forward) contracts-for-difference. In this model setting, nuclear and renewable energies have no chance to diffuse on the market. In the version of the model with boundedly rational investors, nuclear power typically dominates electricity production. We discuss implications of our modelling results for making a transition to low carbon electricity in the future. - Highlights: > We propose a model of a transition from coal to gas in electricity production. > Energy technologies diffuse through the construction of new power plants. > We considered two model versions: with rational and boundedly rational investors. > We quantify model parameters on data for the UK for the period 1990-2002. > We draw policy conclusions for guiding a transition to low carbon electricity.

  12. Industry evolution, rational agents and the transition to sustainable electricity production

    International Nuclear Information System (INIS)

    Safarzynska, Karolina; Bergh, Jeroen C.J.M. van den

    2011-01-01

    Guiding a transition to low carbon electricity requires a good understanding of the substitution of old by new technologies in the electricity industry. With the aim of explaining historical change from coal to gas in the British electricity industry, we develop a formal model of technological change, where energy technologies diffuse through the construction of new power plants. We considered two model versions: with rational and boundedly rational investors. In each model version, we look at the causal relations between price and output setting mechanisms, fuel and labour use, and investment decisions for different institutional arrangements. We quantify model parameters on data for the United Kingdom. We find that the version of the model with rational investors is capable of replicating well core features of UK electricity history. This includes a rapid diffusion of gas in electricity production, the evolution of the average size of newly installed plants, and a high percentage of electricity sales covered by (forward) contracts-for-difference. In this model setting, nuclear and renewable energies have no chance to diffuse on the market. In the version of the model with boundedly rational investors, nuclear power typically dominates electricity production. We discuss implications of our modelling results for making a transition to low carbon electricity in the future. - Highlights: → We propose a model of a transition from coal to gas in electricity production. → Energy technologies diffuse through the construction of new power plants. → We considered two model versions: with rational and boundedly rational investors. → We quantify model parameters on data for the UK for the period 1990-2002. → We draw policy conclusions for guiding a transition to low carbon electricity.

  13. An Experimental Platform for Autonomous Bus Development

    Directory of Open Access Journals (Sweden)

    Héctor Montes

    2017-11-01

    Full Text Available Nowadays, with highly developed instrumentation, sensing and actuation technologies, it is possible to foresee an important advance in the field of autonomous and/or semi-autonomous transportation systems. Intelligent Transport Systems (ITS have been subjected to very active research for many years, and Bus Rapid Transit (BRT is one area of major interest. Among the most promising transport infrastructures, the articulated bus is an interesting, low cost, high occupancy capacity and friendly option. In this paper, an experimental platform for research on the automatic control of an articulated bus is presented. The aim of the platform is to allow full experimentation in real conditions for testing technological developments and control algorithms. The experimental platform consists of a mobile component (a commercial articulated bus fully instrumented and a ground test area composed of asphalt roads inside the Consejo Superior de Investigaciones Científicas (CSIC premises. This paper focuses also on the development of a human machine interface to ease progress in control system evaluation. Some experimental results are presented in order to show the potential of the proposed platform.

  14. State of bus safety in the U.S. : summary of federal and state regulations.

    Science.gov (United States)

    2014-06-01

    This report provides a comprehensive overview of transit bus safety regulations and standards developed by all 50 states, as well as : information on how state departments of transportation (DOT) regulate the maintenance or operation of transit/parat...

  15. Redox transitions in strontium vanadates: Electrical conductivity and dimensional changes

    International Nuclear Information System (INIS)

    Macías, J.; Yaremchenko, A.A.; Frade, J.R.

    2014-01-01

    Highlights: • Electrical conductivity and thermal expansion of strontium vanadates are measured. • Conductivity of SrVO 3−δ is 10 6 –10 8 times higher compared to Sr 2 V 2 O 7 and Sr 3 V 2 O 8 . • Sr 2 V 2 O 7 transforms on reduction to SrVO 3−δ via (5Sr 3 V 2 O 8 + SrV 6 O 11 ) intermediate. • This process is kinetically stagnated due to good redox stability of Sr 3 V 2 O 8 . • Large volume changes on Sr 2 V 2 O 7 ↔ SrVO 3 transformation are confirmed by dilatometry. - Abstract: The reversibility of redox-induced phase transformations and accompanying electrical conductivity and dimensional changes in perovskite-type SrVO 3−δ , a parent material for a family of potential solid oxide fuel cell anode materials, were evaluated employing X-ray diffraction, thermal analysis, dilatometry and electrical measurements. At 873–1273 K, the electrical conductivity of SrVO 3−δ is metallic-like and 6–8 orders of magnitude higher compared to semiconducting V 5+ -based strontium pyrovanadate Sr 2 V 2 O 7 and strontium orthovanadate Sr 3 V 2 O 8 existing under oxidizing conditions. SrVO 3−δ is easily oxidized to a pyrovanadate phase at atmospheric oxygen pressure. Inverse reduction in 10%H 2 –90%N 2 atmosphere occurs in two steps through (5Sr 3 V 2 O 8 + SrV 6 O 11 ) intermediate. As Sr 3 V 2 O 8 is relatively stable even under reducing conditions, the perovskite phase and its high level of electrical conductivity cannot be recovered completely in a reasonable time span at temperatures ⩽1273 K. Dilatometric studies confirmed that SrVO 3 ↔ Sr 2 V 2 O 7 redox transformation is accompanied with significant dimensional changes. Their extent depends on the degree of phase conversion and, apparently, on microstructural features

  16. Circuit breaker and bus

    International Nuclear Information System (INIS)

    Vogel, H.F.

    1978-01-01

    Two close-open operations are required each pulse cycle at approximately 3 MA with the breaker in series with the burn supply, both forming a leg in parallel with the E-coil and the homopolar. To conduct the 3-MA current, approximately 30 breaker units are connected in parallel. Each unit is equipped with a counterpulse capacitor bank, and the bus for the 30 units is provided with a common saturable reactor core made of strip steel wound around the bus. Oil breakers of a special design are chosen because of their high arc resistance facilitating the current transfer to the homopolar machine and for obtaining precision timing in opening and closing of the contacts. The precision timing is achieved by a shock wave method with the oil serving as hydraulic medium. Each of the parallel breaker units possesses two sets of contacts, a stationary and a transient one. A 1-mΩ resistor in series with the transient contacts of each breaker unit is to improve the current sharing. The bus consists of room temperature copper, stranded and transposed to help provide current equalization under transient conditions

  17. Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment.

    Science.gov (United States)

    Ngo, Nicole S

    2015-09-01

    Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards by using bus vintage as a proxy for bus emissions. This is accomplished using a unique, rich panel data set, which includes daily information on bus vintage and route for the New York City Transit bus fleet between 2006 and 2009. This information is merged with daily data on emergency department (ED) visits for respiratory illnesses, which include patients' residences at the census block level and exact admission date. Economic benefits resulting from these bus pollution policies are then estimated. Results show that stricter transit bus emission standards by the U.S. Environmental Protection Agency for particulate matter are associated with reduced ED visits for respiratory diseases for patients living within a few hundred feet of a bus route. These findings demonstrate that bus pollution policies have made critical improvements to public health.

  18. Electricity demand in France: what's at stake for the energy transition?

    International Nuclear Information System (INIS)

    Berghmans, Nicolas

    2017-02-01

    This study identifies five key issues linked to electricity consumption to be taken into consideration in the management of the French power system transition: articulating the building stock renovation strategy and electricity consumption; integrating demand for electricity stemming from the development of electric vehicles; addressing winter 'peak' demand with specific demand-side policies; establishing energy demand management economic models as a flexible solution for the power system; identifying the impact of the emergence of a power system that is decentralised, balanced locally and connected with other energy carriers on the nature of demand for power from the grid. In the context of weak economic and demographic growth, the recent stabilization of electricity demand in France can be attributed to 'structural' factors, i.e. the continued expansion of the tertiary sector in the economy and the acceleration in energy efficiency gains. This evolution was poorly anticipated by stakeholders in the sector, which contributed to an imbalance between electricity demand and supply in Europe. In the absence of a major disruption, planning for transition in the electrical system should be made assuming relatively stable demand. However, major transformations will change the nature of the requirements placed on the electricity system: the times at which energy is consumed, the ability to manage the demand side of the system, and the geographical location of electricity demand within the network. Five key challenges are identified to anticipate the development of electricity consumption patterns: the role of electricity in satisfying building sector heating requirements, the integration of electric vehicle charging, the evolution of the winter demand peak, the development of demand-side management, and the emergence of an electric system based on local-level balancing. Too often considered an exogenous factor, the development in electricity consumption is in fact central

  19. Control of magnetic relaxation by electric-field-induced ferroelectric phase transition and inhomogeneous domain switching

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Tianxiang; Emori, Satoru; Wang, Xinjun; Hu, Zhongqiang; Xie, Li; Gao, Yuan; Lin, Hwaider; Sun, Nian, E-mail: n.sun@neu.edu [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States); Peng, Bin; Liu, Ming, E-mail: mingliu@mail.xjtu.edu.cn [Electronic Materials Research Laboratory, Xi' an Jiaotong University, Xi' an 710049 (China); Jiao, Jie; Luo, Haosu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); Budil, David [Department of Chemistry, Northeastern University, Boston, Massachusetts 02115 (United States); Jones, John G.; Howe, Brandon M.; Brown, Gail J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)

    2016-01-04

    Electric-field modulation of magnetism in strain-mediated multiferroic heterostructures is considered a promising scheme for enabling memory and magnetic microwave devices with ultralow power consumption. However, it is not well understood how electric-field-induced strain influences magnetic relaxation, an important physical process for device applications. Here, we investigate resonant magnetization dynamics in ferromagnet/ferroelectric multiferroic heterostructures, FeGaB/PMN-PT and NiFe/PMN-PT, in two distinct strain states provided by electric-field-induced ferroelectric phase transition. The strain not only modifies magnetic anisotropy but also magnetic relaxation. In FeGaB/PMN-PT, we observe a nearly two-fold change in intrinsic Gilbert damping by electric field, which is attributed to strain-induced tuning of spin-orbit coupling. By contrast, a small but measurable change in extrinsic linewidth broadening is attributed to inhomogeneous ferroelastic domain switching during the phase transition of the PMN-PT substrate.

  20. Electrically controlled band gap and topological phase transition in two-dimensional multilayer germanane

    International Nuclear Information System (INIS)

    Qi, Jingshan; Li, Xiao; Qian, Xiaofeng

    2016-01-01

    Electrically controlled band gap and topological electronic states are important for the next-generation topological quantum devices. In this letter, we study the electric field control of band gap and topological phase transitions in multilayer germanane. We find that although the monolayer and multilayer germananes are normal insulators, a vertical electric field can significantly reduce the band gap of multilayer germananes owing to the giant Stark effect. The decrease of band gap eventually leads to band inversion, transforming them into topological insulators with nontrivial Z_2 invariant. The electrically controlled topological phase transition in multilayer germananes provides a potential route to manipulate topologically protected edge states and design topological quantum devices. This strategy should be generally applicable to a broad range of materials, including other two-dimensional materials and ultrathin films with controlled growth.

  1. Influence of Superconductivity on Crystal Electric Field Transitions in La1-xTbxAl2

    DEFF Research Database (Denmark)

    Feile, R.; Loewenhaupt, M.; Kjems, Jørgen

    1981-01-01

    Inelastic neutron scattering from the crystal electric field transitions in La1-xTbxAl2 single crystals has revealed an abrupt increase in the lifetimes of these transitions when the system becomes superconducting. An increase in the integrated intensities is also observed. The lifetime effects...... are quantitatively reproduced by existing theories, which take into account the reduced scattering of the conduction electrons by the magnetic ions due to the creation of the superconducting energy gap 2Δ(T)....

  2. Transition of radial electric field by electron cyclotron heating in stellarator plasmas

    International Nuclear Information System (INIS)

    Idei, H.; Ida, K.; Sanuki, H.

    1993-06-01

    The transition of a radial electric field from a negative to a positive value is observed in Compact Helical System when the electron loss is sufficiently enhanced by the superposition of the off-axis second harmonic electron cyclotron heating on the neutral beam heated plasmas. The observed threshold for the enhanced particle flux required to cause the transition is compared with a theoretical prediction. (author)

  3. Tunable phase transition in single-layer TiSe2 via electric field

    Science.gov (United States)

    Liu, Lei; Zhuang, Houlong L.

    2018-06-01

    Phase transition represents an intriguing physical phenomenon that exists in a number of single-layer transition-metal dichalcogenides. This phenomenon often occurs below a critical temperature and breaks the long-range crystalline order leading to a reconstructed superstructure called the charge-density wave (CDW) structure, which can therefore be recovered by external stimuli such as temperature. Alternatively, we show here that another external stimulation, electric field can also result in the phase transition between the regular and CDW structures of a single-layer transition-metal dichalcogenide. We used single-layer TiSe2 as an example to elucidate the mechanism of the CDW followed by calculations of the electronic structure using a hybrid density functional. We found that applying electric field can tune the phase transition between the 1T and CDW phases of single-layer TiSe2. Our work opens up a route of tuning the phase transition of single-layer materials via electric field.

  4. Electric field driven orbital order-disorder transition in LaMnO3

    International Nuclear Information System (INIS)

    Bhattacharya, Dipten

    2012-01-01

    The external stimulation such as mechanical pressure magnetic field, electric field, and optical pulse driven phase transition and concomitant gigantic response in physical properties in terms of orders of magnitude jump in electrical resistivity, magnetization, thermoelectric power, or optical constants etc in strongly correlated electron systems has fascinated the researchers for more than two decades now. The underlying physics is nontrivial and the application potential is enormous. We report here our observation of pulsed electric field driven orbital order-disorder transition in canonical orbital ordered system LaMnO 3 . The LaMnO 3 , with orthorhombic crystallographic structure (space group Pbnm), possesses A-type magnetic order below T N (∼ 140 K) and C-type orbital order, with ordering of active 3d 3x 2 -r 2 /3d 3y 2 -r 2 orbitals within a plane and stacking across the plane, below Too (∼ 750 K). We have studied the electrical current-voltage characteristics as well as the differential thermal scans across a wide temperature range 80-800 K under pulsed field on a high quality single crystal of LaMnO 3 . We show how under pulsed electric field, T00 shifts towards lower temperature and the latent heat of the transition decreases monotonically. We also show that the electrical resistivity jumps by more than five orders of magnitude beyond a threshold electric field a low temperature (∼ 80 K). The field driven transition turns out to be originating electro-migration of lattice defects and consequent depinning of orbital domains. The orbital order in LaMnO 3 is not a continuum. It is granular because of interaction with lattice strain, defects, or even interference between Jahn-Teller and MnO 6 tilt order. The domains are pinned by the defects. The electric field driven migration leads to depinning transition. The model of depinning of charge density waves appears to be fitting the data observed in the present case closely, since the orbital order in La

  5. Texas Hydrogen Highway Fuel Cell Hybrid Bus and Fueling Infrastructure Technology Showcase - Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Hitchcock, David

    2012-06-29

    The Texas Hydrogen Highway project has showcased a hydrogen fuel cell transit bus and hydrogen fueling infrastructure that was designed and built through previous support from various public and private sector entities. The aim of this project has been to increase awareness among transit agencies and other public entities on these transportation technologies, and to place such technologies into commercial applications, such as a public transit agency. The initial project concept developed in 2004 was to show that a skid-mounted, fully-integrated, factory-built and tested hydrogen fueling station could be used to simplify the design, and lower the cost of fueling infrastructure for fuel cell vehicles. The approach was to design, engineer, build, and test the integrated fueling station at the factory then install it at a site that offered educational and technical resources and provide an opportunity to showcase both the fueling station and advanced hydrogen vehicles. The two primary technology components include: Hydrogen Fueling Station: The hydrogen fueling infrastructure was designed and built by Gas Technology Institute primarily through a funding grant from the Texas Commission on Environmental Quality. It includes hydrogen production, clean-up, compression, storage, and dispensing. The station consists of a steam methane reformer, gas clean-up system, gas compressor and 48 kilograms of hydrogen storage capacity for dispensing at 5000 psig. The station is skid-mounted for easy installation and can be relocated if needed. It includes a dispenser that is designed to provide temperaturecompensated fills using a control algorithm. The total station daily capacity is approximately 50 kilograms. Fuel Cell Bus: The transit passenger bus built by Ebus, a company located in Downey, CA, was commissioned and acquired by GTI prior to this project. It is a fuel cell plug-in hybrid electric vehicle which is ADA compliant, has air conditioning sufficient for Texas operations

  6. Electric dipole transitions for four-times ionized cerium (Ce V)

    Energy Technology Data Exchange (ETDEWEB)

    Usta, Betül Karaçoban, E-mail: bkaracoban@sakarya.edu.tr; Akgün, Elif, E-mail: elif.akgun@ogr.sakarya.edu.tr; Alparslan, Büşra, E-mail: busra.alparslan1@ogr.sakarya.edu.tr [Physics Department, Sakarya University, 54187, Sakarya (Turkey)

    2016-03-25

    We have calculated the transition parameters, such as wavelengths, oscillator strengths, and transition probabilities (or rates), for the electric dipole (E1) transitions in four-times ionized cerium (Ce V, Z = 58) by using the multiconfiguration Hartree-Fock method within the framework of Breit-Pauli (MCHF+BP) relativistic corrections and the relativistic Hartree-Fock (HFR) method. The obtained results have been compared with other works available in literature. A discussion of these calculations for Ce V in this study has also been in view of the MCHF+BP and HFR methods.

  7. Identification of voltage stability condition of a power system using measurements of bus variables

    Directory of Open Access Journals (Sweden)

    Durlav Hazarika

    2014-12-01

    Full Text Available Several online methods were proposed for investigating the voltage stability condition of an interconnected power system using the measurements of voltage and current phasors at a bus. For this purpose, phasor measurement units (PMUs are used. A PMU is a device which measures the electrical waves on an electrical network, using a common time source (reference bus for synchronisation. This study proposes a method for online monitoring of voltage stability condition of a power system using measurements of bus variables namely – (i real power, (ii reactive power and (iii bus voltage magnitude at a bus. The measurements of real power, reactive power and bus voltage magnitude could be extracted/captured from a smart energy meter. The financial involvement for implementation of the proposed method would significantly lower compared with the PMU-based method.

  8. Best Operational and Maintenance Practices for City Bus Fleets to Maximize Fuel Economy

    OpenAIRE

    Energy Sector Management Assistance Program

    2011-01-01

    In most large cities in developing countries, buses continue to be the public transport option of choice, carrying a large share of urban travelers. However, transit bus companies in these countries are often cash-strapped. In many cases, the operating cost per bus kilometer exceeds revenues and bus fares are often kept low irrespective of the cost of providing service. Many cities are dom...

  9. An economic and legal perspective on electric utility transition costs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.

    1996-07-01

    The issue of possibly unrecoverable cost incurred by a utility, or `stranded costs,` has emerged as a major obstacle to developing a competitive generation market. Stranded or transition costs are defined as costs incurred by a utility to serve its customers that were being recovered in rates but are no longer due to availability of lower-priced alternative suppliers. The idea of `stranded cost,` and more importantly arguments for its recovery, is a concept with little basis in economic theory, legal precedence, or precedence in other deregulated industries. The main argument recovery is that the ``regulatory compact`` requires it. This is based on the misconception that the regulator compact is simply: the utility incurs costs on behalf of its customers because of the ``obligation to serve`` so, therefore, customers are obligated to pay. This is a mischaracterization of what the compact was and how it developed. Another argument is that recovery is required for economic efficiency. This presumes, however, a very narrow definition of efficiency based on preventing ``uneconomic`` bypass of the utility and that utilities minimize costs. A broader definition of efficiency and the likelihood of cost inefficiencies in the industry suggest that the cost imposed on customers from inhibiting competition could exceed the gains from preventing uneconomic bypass. Both these issues are examined in this paper.

  10. Study of Electric Monopole Transitions in $^{76,78}$Kr

    CERN Multimedia

    2002-01-01

    In the run at ISOLDE performed last August we completed the study of the decay properties of the $ 0 ^{+} _{2} $ level in $ ^{76, 78, 80}$Kr by measuring the lifetime of the $ 0 ^{+} _{2} $ level in $^{76}$Kr. This was done by applying the $\\beta \\gamma\\gamma$ (t) fast timing method to the $\\beta^{+} $-decay of $^{76}$Rb. For the first time the method was applied to proton-rich nuclei at ISOLDE. This required some special modifications of the experimental set-up previously used for the case of $\\beta^{-}$-decay due to the presence of intense annihilation radiation. The experiment has been successful and enough data have been collected for the determination of the lifetime. The analysis is in progress. From a very preliminary estimate it would appear that the lifetime value falls in the range 20-60 ps. Combining this value with the previously measured ratio \\[\\frac{B(E0; 0^{+}_{2} \\rightarrow 0^{+}_{1})}{B(E2; 0^{+}_{2} \\rightarrow 2^{+}_{1})}\\] It is possible to extract an estimate of the monopole transition...

  11. A Transition Strategy from Fossil Fuels to Renewable Energy Sources in the Mexican Electricity System

    Directory of Open Access Journals (Sweden)

    Juan J. Vidal-Amaro

    2018-03-01

    Full Text Available Renewable energy sources exploitation acquires special importance for creating low-carbon energy systems. In Mexico a national regulation limits the fossil fuel-based electricity generation to 65%, 60% and 50% by years 2024, 2030 and 2050 respectively. This study evaluates several scenarios of renewables incorporation into the Mexican electricity system to attend those targets as well as a 75% renewables-based electricity share target towards a 100% renewable system. By its size, the Mexican electricity system, with a generation of 260.4 TWh/year (85% based on fossil fuels, can be regarded as an illustrating reference. The impact of increasing amounts of wind, photovoltaic solar, biomass, biogas, geothermal, hydro and concentrating solar power on the system’s capacity to attend demand on a one-hour timescale resolution is investigated utilizing the EnergyPLAN model and the minimum total mix capacity method. Possible excess of electricity production is also assessed. For every target year, a solution is obtained corresponding to the combination resulting in the minimum total generation capacity for the electricity system. A transition strategy to a system with a high share of renewables-based electricity is designed where every transition step corresponds to the optimal energy mix for each of the target years.

  12. In-use fuel economy of hybrid-electric school buses in Iowa.

    Science.gov (United States)

    Hallmark, Shauna; Sperry, Bob; Mudgal, Abhisek

    2011-05-01

    Although it is much safer and more fuel-efficient to transport children to school in buses than in private vehicles, school buses in the United States still consume 822 million gal of diesel fuel annually, and school transportation costs can account for a significant portion of resource-constrained school district budgets. Additionally, children in diesel-powered school buses may be exposed to higher levels of particulates and other pollutants than children in cars. One solution to emission and fuel concerns is use of hybrid-electric school buses, which have the potential to reduce emissions and overall lifecycle costs compared with conventional diesel buses. Hybrid-electric technologies are available in the passenger vehicle market as well as the transit bus market and have a track record indicating fuel economy and emissions benefits. This paper summarizes the results of an in-use fuel economy evaluation for two plug-in hybrid school buses deployed in two different school districts in Iowa. Each school district selected a control bus with a route similar to that of the hybrid bus. Odometer readings, fuel consumption, and maintenance needs were recorded for each bus. The buses were deployed in 2008 and data were collected through May 2010. Fuel consumption was calculated for each school district. In Nevada, IA, the overall average fuel economy was 8.23 mpg for the hybrid and 6.35 mpg for the control bus. In Sigourney, IA, the overall average fuel economy was 8.94 mpg for the hybrid and 6.42 mpg for the control bus. The fuel consumption data were compared for the hybrid and control buses using a Wilcoxon signed rank test. Results indicate that fuel economy for the Nevada hybrid bus was 29.6% better than for the Nevada control bus, and fuel economy for the Sigourney hybrid bus was 39.2% higher than for the Sigourney control bus. Both differences were statistically significant.

  13. Thermal battery. [solid metal halide electrolytes with enhanced electrical conductance after a phase transition

    Science.gov (United States)

    Carlsten, R.W.; Nissen, D.A.

    1973-03-06

    The patent describes an improved thermal battery whose novel design eliminates various disadvantages of previous such devices. Its major features include a halide cathode, a solid metal halide electrolyte which has a substantially greater electrical conductance after a phase transition at some temperature, and a means for heating its electrochemical cells to activation temperature.

  14. Proceedings of the CERI 2003 electricity conference : electricity restructuring in transition. CD-ROM ed.

    International Nuclear Information System (INIS)

    2003-01-01

    The restructuring of the electric power industry was reviewed from a North American perspective. This conference focused on how current market structures can be improved to benefit all participants. The current issues for future development of power generation and transmission were discussed. The conference was divided into seven sessions as follows: (1) market design issues, (2) Federal Energy Regulatory Commission's (FERC's) wholesale market platform, (3) does retail competition make sense, (4) the future direction of the Alberta market, (5) the status of restructured electricity markets, (6) resource mix in a greenhouse gas (GHG)-constrained world, and (7) electricity supply from oil sands cogeneration. A total of eleven papers were selected and indexed separately for inclusion in this database. refs., tabs., figs

  15. Glass-Glass Transitions by Means of an Acceptor-Donor Percolating Electric-Dipole Network

    Science.gov (United States)

    Zhang, Le; Lou, Xiaojie; Wang, Dong; Zhou, Yan; Yang, Yang; Kuball, Martin; Carpenter, Michael A.; Ren, Xiaobing

    2017-11-01

    We report the ferroelectric glass-glass transitions in KN (K+/Nb5 +) -doped BaTiO3 ferroelectric ceramics, which have been proved by x-ray diffraction profile and Raman spectra data. The formation of glass-glass transitions can be attributed to the existence of cubic (C )-tetragonal (T )-orthorhombic (O )-rhombohedral (R ) ferroelectric transitions in short-range order. These abnormal glass-glass transitions can perform very small thermal hysteresis (approximately 1.0 K ) with a large dielectric constant (approximately 3000), small remanent polarization Pr , and relative high maximum polarization Pm remaining over a wide temperature range (220-350 K) under an electrical stimulus, indicating the potential applications in dielectric recoverable energy-storage devices with high thermal reliability. Further phase field simulations suggest that these glass-glass transitions are induced by the formation of a percolating electric defect-dipole network (PEDN). This proper PEDN breaks the long-range ordered ferroelectric domain pattern and results in the local phase transitions at the nanoscale. Our work may further stimulate the fundamental physical theory and accelerate the development of dielectric energy-storing devices.

  16. International perspectives on the importance of electric tariff transitioning to cost-based levels in Bulgaria

    International Nuclear Information System (INIS)

    Simpson, T.; Davis, F.; Dilovska, I.

    1996-01-01

    The traditional cost-of-service approach to power pricing has been replaced in many countries by market pricing mechanisms that compensate power producers at the marginal cost of production established collectively in the marketplace. The paper stresses the importance of cost-based tariff setting pointing out two main pricing principles of utility services: 1) Revenues must meet or exceed the utility average cost of production; 2) Marginal cost pricing for incremental consumption must ensure efficient allocation of resources. Examples describing the factors encouraging transition to economically efficient tariffs at a small utility are given for: Northwest U.S., MINENERGO in Belarus, Pacific Gas and Electric Co in California and the National Electric Co (NEK) in Bulgaria.The analysis of the Bulgarian electric sector is based on ongoing work being funded by the U.S. Agency for International Development. Each of the four utilities described faces a different challenge for transitioning tariffs to cost- based levels. However, one and the same broad conclusion applies in all cases: utility pricing must take into account the underlying average and marginal cost structures of the regional power industry. Bulgaria needs transition to cost-based tariffs to recover the electricity cost-of-service and to ensure that the electric sector operates efficiently and consumers are treated fairly. Measures that facilitate the process of tariff transitioning include: 1) Developing a transparent process of tariff setting with clear objectives, a plan and timetable, and roles of organizations; 2) Establishing of independent regulation to ensure that tariff setting objectives are achieved; 3) Instituting mechanisms to reward organizations for performance that achieves electric sector objectives. 3 figs

  17. Directly connected series coupled HTPEM fuel cell stacks to a Li-ion battery DC bus for a fuel cell electrical vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    The work presented in this paper examines the use of pure hydrogen fuelled high temperature polymer electrolyte membrane (HTPEM) fuel cell stacks in an electrical car, charging a Li-ion battery pack. The car is equipped with two branches of two series coupled 1 kW fuel cell stacks which...... are connected directly parallel to the battery pack during operation. This enables efficient charging of the batteries for increased driving range. With no power electronics used, the fuel cell stacks follow the battery pack voltage, and charge the batteries passively. This saves the electrical and economical...... losses related to these components and their added system complexity. The new car battery pack consists of 23 Li-ion battery cells and the charging and discharging are monitored by a battery management system (BMS) which ensures safe operating conditions for the batteries. The direct connection...

  18. Fuel Cell Buses in U.S. Transit Fleets : Current Status 2013

    Science.gov (United States)

    2013-12-01

    This report is the seventh in an annual series of reports that summarize the progress of fuel cell electric bus (FCEB) development in the United States and discuss the achievements and challenges of introducing fuel cell propulsion in transit. This r...

  19. Fuel Cell Buses in U.S. Transit Fleets : Current Status 2012

    Science.gov (United States)

    2012-11-12

    This report is the sixth in an annual series of reports that summarize the progress of fuel cell electric bus (FCEB) development in the United States and discuss the achievements and challenges of introducing fuel cell propulsion in transit. The repo...

  20. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2012

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chandler, Kevin [Battelle, Columbus, OH (United States); Gikakis, Christina [Federal Transit Administration, Washington, DC (United States)

    2012-11-01

    This report is the sixth in an annual series of reports that summarize the progress of fuel cell electric bus (FCEB) development in the United States and discuss the achievements and challenges of introducing fuel cell propulsion in transit. The report also provides a snapshot of current FCEB performance results over the last year.

  1. Determination of the Optimum Heat Transfer Coefficient and Temperature Rise Analysis for a Lithium-Ion Battery under the Conditions of Harbin City Bus Driving Cycles

    Directory of Open Access Journals (Sweden)

    Xiaogang Wu

    2017-10-01

    Full Text Available This study investigated the heat problems that occur during the operation of power batteries, especially thermal runaway, which usually take place in high temperature environments. The study was conducted on a ternary polymer lithium-ion battery. In addition, a lumped parameter thermal model was established to analyze the thermal behavior of the electric bus battery system under the operation conditions of the driving cycles of the Harbin city electric buses. Moreover, the quantitative relationship between the optimum heat transfer coefficient of the battery and the ambient temperature was investigated. The relationship between the temperature rise (Tr, the number of cycles (c, and the heat transfer coefficient (h under three Harbin bus cycles have been investigated at 30 °C, because it can provide a basis for the design of the battery thermal management system. The results indicated that the heat transfer coefficient that meets the requirements of the battery thermal management system is the cubic power function of the ambient temperature. Therefore, if the ambient temperature is 30 °C, the heat transfer coefficient should be at least 12 W/m2K in the regular bus lines, 22 W/m2K in the bus rapid transit lines, and 32 W/m2K in the suburban lines.

  2. Learning NServiceBus Sagas

    CERN Document Server

    Helton, Rich

    2015-01-01

    If you are an Enterprise C# developer who wishes to extend your knowledge of NServiceBus and Enterprise Service Bus in C#, this is the book for you. This book is designed to enhance the education of ESBs and their messaging, whether you are a beginner or a seasoned expert in Enterprise C#, Apex, and Visualforce pages.

  3. Improvement of multiprocessing performance by using optical centralized shared bus

    Science.gov (United States)

    Han, Xuliang; Chen, Ray T.

    2004-06-01

    With the ever-increasing need to solve larger and more complex problems, multiprocessing is attracting more and more research efforts. One of the challenges facing the multiprocessor designers is to fulfill in an effective manner the communications among the processes running in parallel on multiple multiprocessors. The conventional electrical backplane bus provides narrow bandwidth as restricted by the physical limitations of electrical interconnects. In the electrical domain, in order to operate at high frequency, the backplane topology has been changed from the simple shared bus to the complicated switched medium. However, the switched medium is an indirect network. It cannot support multicast/broadcast as effectively as the shared bus. Besides the additional latency of going through the intermediate switching nodes, signal routing introduces substantial delay and considerable system complexity. Alternatively, optics has been well known for its interconnect capability. Therefore, it has become imperative to investigate how to improve multiprocessing performance by utilizing optical interconnects. From the implementation standpoint, the existing optical technologies still cannot fulfill the intelligent functions that a switch fabric should provide as effectively as their electronic counterparts. Thus, an innovative optical technology that can provide sufficient bandwidth capacity, while at the same time, retaining the essential merits of the shared bus topology, is highly desirable for the multiprocessing performance improvement. In this paper, the optical centralized shared bus is proposed for use in the multiprocessing systems. This novel optical interconnect architecture not only utilizes the beneficial characteristics of optics, but also retains the desirable properties of the shared bus topology. Meanwhile, from the architecture standpoint, it fits well in the centralized shared-memory multiprocessing scheme. Therefore, a smooth migration with substantial

  4. Secure and Efficient Electricity Supply. During the Transition to Low Carbon Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    Electricity shortages can paralyse our modern economies. All governments fear rolling black-outs and their economic consequences, especially in economies increasingly based on digital technologies. Over the last two decades, the development of markets for power has produced cost reduction, technological innovation, increased cross border trade and assured a steady supply of electricity. Now, IEA countries face the challenge of maintaining security of electricity supply during the transition to low-carbon economies. Low-carbon policies are pushing electricity markets into novel territories at a time when most of the generation and network capacity will have to be replaced. Most notably, wind and solar generation, now an integral part of electricity markets, can present new operating and investment challenges for generation, networks and the regional integration of electricity markets. In addition, the resilience of power systems facing more frequent natural disasters is also of increasing concern. IEA Ministers mandated the Secretariat to work on the Electricity Security Action Plan (ESAP), expanding to electricity the energy security mission of the IEA. This paper outlines the key conclusions and policy recommendations to ''keep the lights on'' while reducing CO2 emissions and increasing the efficiency.

  5. 77 FR 74452 - Bus Testing: Calculation of Average Passenger Weight and Test Vehicle Weight

    Science.gov (United States)

    2012-12-14

    ... require FTA to work with bus manufacturers and transit agencies to establish a new pass/ fail standard for... buses from the current value of 150 pounds to a new value of 175 pounds. This increase was proposed to... new pass/fail standards that require a more comprehensive review of its overall bus testing program...

  6. Actively Controlling the Topological Transition of Dispersion Based on Electrically Controllable Metamaterials

    Directory of Open Access Journals (Sweden)

    Zhiwei Guo

    2018-04-01

    Full Text Available Topological transition of the iso-frequency contour (IFC from a closed ellipsoid to an open hyperboloid provides unique capabilities for controlling the propagation of light. However, the ability to actively tune these effects remains elusive, and the related experimental observations are highly desirable. Here, a tunable electric IFC in a periodic structure composed of graphene/dielectric multilayers is investigated by tuning the chemical potential of the graphene layer. Specially, we present the actively controlled transportation in two kinds of anisotropic zero-index media containing perfect electric conductor/perfect magnetic conductor impurities. Finally, by adding variable capacitance diodes into a two-dimensional transmission-line system, we present an experimental demonstration of the actively controlled magnetic topological transition of dispersion based on electrically controllable metamaterials. With the increase in voltage, we measure the different emission patterns from a point source inside the structure and observe the phase-transition process of IFCs. The realization of an actively tuned topological transition will open up a new avenue in the dynamical control of metamaterials.

  7. Comparing electricity transitions: A historical analysis of nuclear, wind and solar power in Germany and Japan

    International Nuclear Information System (INIS)

    Cherp, Aleh; Vinichenko, Vadim; Jewell, Jessica; Suzuki, Masahiro; Antal, Miklós

    2017-01-01

    This paper contributes to understanding national variations in using low-carbon electricity sources by comparing the evolution of nuclear, wind and solar power in Germany and Japan. It develops and applies a framework for analyzing low-carbon electricity transitions based on interplay of techno-economic, political and socio-technical processes. We explain why in the 1970s–1980s, the energy paths of the two countries were remarkably similar, but since the 1990s Germany has become a leader in renewables while phasing out nuclear energy, whereas Japan has deployed less renewables while becoming a leader in nuclear power. We link these differences to the faster growth of electricity demand and energy insecurity in Japan, the easier diffusion of onshore wind power technology and the weakening of the nuclear power regime induced by stagnation and competition from coal and renewables in Germany. We show how these changes involve the interplay of five distinct mechanisms which may also play a role in other energy transitions. - Highlights: • We identify five mechanisms which play a role in national low-carbon electricity transitions. • Use of nuclear, wind and solar power in Germany and Japan diverged in the 1990s. • Wind power diffused to Germany from Denmark but different geography stalled it in Japan. • Demand growth and energy insecurity prompted nuclear power expansion in Japan. • Competition with domestic coal and wind led to the demise of nuclear power in Germany.

  8. Cellular Automata Based Modeling for Evaluating Different Bus Stop Designs in China

    Directory of Open Access Journals (Sweden)

    Haoyang Ding

    2015-01-01

    Full Text Available A cellular automaton model is proposed to simulate mixed traffic flow composed of motor vehicles and bicycles near bus stops. Three typical types of bus stops which are common in China are considered in the model, including two types of curbside bus stops and one type of bus bay stops. Passenger transport capacity of three types of bus stops, which is applied to evaluate the bus stop design, is calculated based on the corresponding traffic flow rate. According to the simulation results, the flow rates of both motor vehicles and bicycles exhibit phase transition from free flow to the saturation one at the critical point. The results also show that the larger the interaction between motor vehicle and bicycle flow is near curbside bus stops, the more the value of saturated flows drops. Curbside bus stops are more suitable when the conflicts between two flows are small and the inflow rate of motor vehicles is low. On the contrary, bus bay stops should be applied due to their ability to reduce traffic conflicts. Findings of this study can provide useful suggestions on bus stop selection considering different inflow rate of motor vehicles and bicycles simultaneously.

  9. Coordination of IVI and transit signal priority on transit evacuations.

    Science.gov (United States)

    2011-02-01

    During an emergency evacuation, execution time is always critical to the evacuees who are : transit dependent. Transit Signal Priority (TSP) can speed up the transit services by prioritizing : the approaching bus at a signalized intersection. With th...

  10. Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

    Science.gov (United States)

    Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

    2005-07-01

    Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

  11. Electric field-triggered metal-insulator transition resistive switching of bilayered multiphasic VOx

    Science.gov (United States)

    Won, Seokjae; Lee, Sang Yeon; Hwang, Jungyeon; Park, Jucheol; Seo, Hyungtak

    2018-01-01

    Electric field-triggered Mott transition of VO2 for next-generation memory devices with sharp and fast resistance-switching response is considered to be ideal but the formation of single-phase VO2 by common deposition techniques is very challenging. Here, VOx films with a VO2-dominant phase for a Mott transition-based metal-insulator transition (MIT) switching device were successfully fabricated by the combined process of RF magnetron sputtering of V metal and subsequent O2 annealing to form. By performing various material characterizations, including scanning transmission electron microscopy-electron energy loss spectroscopy, the film is determined to have a bilayer structure consisting of a VO2-rich bottom layer acting as the Mott transition switching layer and a V2O5/V2O3 mixed top layer acting as a control layer that suppresses any stray leakage current and improves cyclic performance. This bilayer structure enables excellent electric field-triggered Mott transition-based resistive switching of Pt-VOx-Pt metal-insulator-metal devices with a set/reset current ratio reaching 200, set/reset voltage of less than 2.5 V, and very stable DC cyclic switching upto 120 cycles with a great set/reset current and voltage distribution less than 5% of standard deviation at room temperature, which are specifications applicable for neuromorphic or memory device applications. [Figure not available: see fulltext.

  12. Electrical Switching in Thin Film Structures Based on Transition Metal Oxides

    Directory of Open Access Journals (Sweden)

    A. Pergament

    2015-01-01

    Full Text Available Electrical switching, manifesting itself in the nonlinear current-voltage characteristics with S- and N-type NDR (negative differential resistance, is inherent in a variety of materials, in particular, transition metal oxides. Although this phenomenon has been known for a long time, recent suggestions to use oxide-based switching elements as neuristor synapses and relaxation-oscillation circuit components have resumed the interest in this area. In the present review, we describe the experimental facts and theoretical models, mainly on the basis of the Mott transition in vanadium dioxide as a model object, of the switching effect with special emphasis on the emerging applied potentialities for oxide electronics.

  13. Stark Interference of Electric and Magnetic Dipole Transitions in the A-X Band of OH.

    Science.gov (United States)

    Schewe, H Christian; Zhang, Dongdong; Meijer, Gerard; Field, Robert W; Sartakov, Boris G; Groenenboom, Gerrit C; van der Avoird, Ad; Vanhaecke, Nicolas

    2016-04-15

    An experimental method is demonstrated that allows determination of the ratio between the electric (E1) and magnetic (M1) transition dipole moments in the A-X band of OH, including their relative sign. Although the transition strengths differ by more than 3 orders of magnitude, the measured M1-to-E1 ratio agrees with the ratio of the ab initio calculated values to within 3%. The relative sign is found to be negative, also in agreement with theory.

  14. Energies and electric dipole transitions for low-lying levels of protactinium IV and uranium V

    Energy Technology Data Exchange (ETDEWEB)

    Uerer, Gueldem; Oezdemir, Leyla [Sakarya Univ. (Turkey). Physics Dept.

    2012-01-15

    We have reported a relativistic multiconfiguration Dirac-Fock (MCDF) study on low-lying level structures of protactinium IV (Z = 91) and uranium V (Z = 92) ions. Excitation energies and electric dipole (E1) transition parameters (wavelengths, oscillator strengths, and transition rates) for these low-lying levels have been given. We have also investigated the influence of the transverse Breit and quantum electrodynamic (QED) contributions besides correlation effects on the level structure. A comparison has been made with a few available data for these ions in the literature. (orig.)

  15. Electricity tariff design for transition economies. Application to the Libyan power system

    Energy Technology Data Exchange (ETDEWEB)

    Reneses, Javier; Gomez, Tomas; Rivier, Juan [Universidad Pontificia Comillas, Madrid (Spain); Angarita, Jorge L. [Europraxis Operations, Madrid (Spain)

    2011-01-15

    This paper presents a general electricity tariff design methodology, especially applicable for transition economies. These countries are trying to modernize their power systems from a centralized environment (with normally, a public vertically integrated electric company) to a liberalized framework (unbundling electricity companies and, eventually, starting a privatization process). Two issues arise as crucial to achieving a successful transition: (1) ensuring cost recovery for all future unbundled activities (generation, transmission, distribution and retailing), and (2) sending the right price signals to electricity customers, avoiding cross-subsidies between customer categories. The design of electricity tariffs plays a pivotal role in achieving both objectives. This paper proposes a new tariff design methodology that, complying with these two aforementioned criteria, requires a low amount of information regarding system data and customer load profiles. This is important since, typically, volume and quality of data are poor in those countries. The presented methodology is applied to computing tariffs for the Libyan power system in 2006, using real data. (author)

  16. Optimum Dispatch of Hybrid Solar Thermal (HSTP Electric Power Plant Using Non-Smooth Cost Function and Emission Function for IEEE-30 Bus System

    Directory of Open Access Journals (Sweden)

    Saroj Kumar Dash

    2016-07-01

    Full Text Available The basic objective of economic load dispatch (ELD is to optimize the total fuel cost of hybrid solar thermal electric power plant (HSTP. In ELD problems the cost function for each generator has been approximated by a single quadratic cost equation. As cost of coal increases, it becomes even more important have a good model for the production cost of each generator for the solar thermal hybrid system. A more accurate formulation is obtained for the ELD problem by expressing the generation cost function as a piece wise quadratic cost function. However, the solution methods for ELD problem with piece wise quadratic cost function requires much complicated algorithms such as the hierarchical structure approach along with evolutionary computations (ECs. A test system comprising of 10 units with 29 different fuel [7] cost equations is considered in this paper. The applied genetic algorithm method will provide optimal solution for the given load demand.

  17. MIL-STD-1553 dynamic bus controller/remote terminal hybrid set

    Science.gov (United States)

    Friedman, S. N.

    This paper describes the performance, physical and electrical requirements of a Dual Redundant BUS Interface Unit (BIU) acting as a BUS Controller Interface Unit (BCIU) or Remote Terminal Unit (RTU) between a Motorola 68000 VME BUS and MIL-STD-1553B Multiplex Data Bus. A discussion of how the BIU Hybrid set is programmed, and operates as a BCIU or RTU, will be included. This paper will review Dynamic Bus Control and other Mode Code capabilities. The BIU Hybrid Set interfaces to a 68000 Microprocessor with a VME Bus using programmed I/O transfers. This special interface will be discussed along with the internal Dual Access Memory (4K x 16) used to support the data exchanges between the CPU and the BIU Hybrid Set. The hybrid set's physical size and power requirements will be covered. This includes the present Double Eurocard the BIU function is presently being offered on.

  18. Natural gas powered bus

    International Nuclear Information System (INIS)

    Ambuehl, D.; Fernandez, J.

    2003-01-01

    This report for the Swiss Federal Office of Energy presents the results of a project carried out by the Swiss Federal Institute of Technology in Zurich to evaluate the performance of a natural-gas-powered bus in comparison with two diesel buses. The report provides details on the vehicles, their routes and the results of interviews made with both passengers and drivers. Details of measurements made on fuel consumption and pollutant emissions are presented in tabular and graphical form, as are those made on noise emissions inside and outside the vehicles. The conclusions of the project are presented including economic aspects of using gas as a motor fuel. Also, the views of passengers, who were more concerned with comfort aspects, and drivers, who were more interested in technical aspects, are quoted

  19. Assessing Bus Performance Rating in Kajang, Selangor

    Science.gov (United States)

    Norhisham, S.; Ismail, A.; Sidek, L. M.; Borhan, M. N.; Zaini, N.; Yen, A. T. G.

    2018-04-01

    The Transit Capacity and Quality of Service Manual (TCQSM) was chosen based on the review with four manuals and guidelines for the method will be applied. Six (6) attributes, namely Hours of Service, Passenger Load, Transit Auto Travel Time, Service Frequency, Punctuality Performance and Service Coverage were chosen for evaluation.[6][7][8]. A total of three (3) operators with seven (7) routes were identified in Kajang. Based on the final results, the Quality of Service (QOS) findings was rated as D, which was regarded as minimum or satisfactory. Most stakeholders’ recommendations were: for the operators to provide information on bus scheduling and have accurate information for the passengers. It was suggested that in future this study can be extended to all routes and could be repeated after the opening of the Mass Rapid Transit (MRT) stations in Kajang, so as to provide a comparison and better evaluation of the public buses in Kajang.

  20. Impacts on the biophysical economy and environment of a transition to 100% renewable electricity in Australia

    International Nuclear Information System (INIS)

    Turner, Graham M.; Elliston, Ben; Diesendorf, Mark

    2013-01-01

    We investigate the impacts on the biophysical economy, employment and environment of a transition scenario to an energy-efficient, 100% renewable electricity (RE) system by 2060, based on wind, solar and biomass technologies, and an introduction of electric vehicles. We employ a CSIRO process-based model of the physical activity of Australia’s economy and environmental resources, the Australian Stocks and Flows Framework. The RE systems are assumed to be manufactured in Australia to identify possible employment benefits. In comparison with the business-as-usual (BAU) scenario, on a national scale, the RE scenario has much lower economy-wide net emissions, remaining below contemporary levels and becoming zero in the electricity sector by 2060. Compared with BAU, the RE scenario also has significantly lower industrial water use, somewhat higher materials use, slightly lower unemployment, lower net foreign debt (relative to a GDP proxy) and, resulting from the growth in electric vehicles, reduced oil imports. The GDP per capita growth, based on the physical stocks of capital and labour, is virtually the same in both scenarios. Hence, from the viewpoint of the biophysical economy, there are no major barriers to implementing policies to facilitate the transition to a 100% renewable electricity system for Australia. - Highlights: ► Simulation of a 100% renewable electricity (RE) system in a process-based model. ► The RE scenario achieves zero GHG emissions in the electricity sector by 2060. ► Consumption of secondary materials is higher and more variable in the RE scenario. ► The RE scenario has lower water use, unemployment, foreign debt and oil imports

  1. Conductance fluctuations and distribution at metal-insulator transition induced by electric field in disordered chain

    International Nuclear Information System (INIS)

    Senouci, Khaled

    2000-08-01

    A simple Kronig-Penney model for 1D mesoscopic systems with δ peak potentials is used to study numerically the influence of a constant electric field on the conductance fluctuations and distribution at the transition. We found that the conductance probability distribution has a system-size independent form with large fluctuations in good agreement with the previous works in 2D and 3D systems. (author)

  2. 76 FR 37184 - Discretionary Bus and Bus Facilities Program

    Science.gov (United States)

    2011-06-24

    ... transporting bicycles on public transportation vehicles. The FY 2011 Appropriations Act allows a 90 percent Federal share for the total cost of a biodiesel bus. The Act also allows a 90 percent Federal share for...

  3. Sustainable electricity transitions in Germany in a spatial context: between localism and centralism

    Directory of Open Access Journals (Sweden)

    Gerhard Fuchs

    2014-01-01

    Full Text Available While the traditional form of electricity generation and supply is based on centralized structures with large-scale power plants, the objective of a strongly decentralized form of energy supply is increasingly becoming important. Sustainability-oriented energy transitions are relying on various sorts of renewable energies coupled with energy-efficiency initiatives. In the current existing regulatory and market frameworks in Germany and elsewhere, important technical and institutional innovations for energy transitions were and are being developed, tested, and brought to application on regional and local levels. Regions, cities, and villages experimenting with socio-technical innovations and aiming to implement new concepts have to develop governance structures under high uncertainty. These governance structures mirror space-specific social, political, technological and economic constellations. The present article introduces an analytical approach for studying emergent forms of governance and uses four cases from Germany to apply the approach. Research is based on a comparative case study research design, using primarily expert interviews and document analyses as data sources. The cases demonstrate that sustainable energy transitions are driven forward by a host of different actors with different aims and interests, culminating in the development of space-specific technological mixes and situative governance structures. Sustainable energy transitions neither follow a master plan, nor are they coordinated on a national level. The upper political levels and external events pose severe constraints for the implementation of local transition initiatives. Future research should aim to highlight and analyze the contentious character of energy transitions.

  4. Electric transition dipole moment in pre-Born-Oppenheimer molecular structure theory.

    Science.gov (United States)

    Simmen, Benjamin; Mátyus, Edit; Reiher, Markus

    2014-10-21

    This paper presents the calculation of the electric transition dipole moment in a pre-Born-Oppenheimer framework. Electrons and nuclei are treated equally in terms of the parametrization of the non-relativistic total wave function, which is written as a linear combination of basis functions constructed from explicitly correlated Gaussian functions and the global vector representation. The integrals of the electric transition dipole moment are derived corresponding to these basis functions in both the length and the velocity representation. The calculations are performed in laboratory-fixed Cartesian coordinates without relying on coordinates which separate the center of mass from the translationally invariant degrees of freedom. The effect of the overall motion is eliminated through translationally invariant integral expressions. The electric transition dipole moment is calculated between two rovibronic levels of the H2 molecule assignable to the lowest rovibrational states of the X (1)Σ(g)(+) and B (1)Σ(u)(+) electronic states in the clamped-nuclei framework. This is the first evaluation of this quantity in a full quantum mechanical treatment without relying on the Born-Oppenheimer approximation.

  5. Configurational entropy of polar glass formers and the effect of electric field on glass transition

    Energy Technology Data Exchange (ETDEWEB)

    Matyushov, Dmitry V., E-mail: dmitrym@asu.edu [Department of Physics and School of Molecular Sciences, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287 (United States)

    2016-07-21

    A model of low-temperature polar liquids is constructed that accounts for the configurational heat capacity, entropy, and the effect of a strong electric field on the glass transition. The model is based on the Padé-truncated perturbation expansions of the liquid state theory. Depending on parameters, it accommodates an ideal glass transition of vanishing configurational entropy and its avoidance, with a square-root divergent enumeration function at the point of its termination. A composite density-temperature parameter ρ{sup γ}/T, often used to represent combined pressure and temperature data, follows from the model. The theory is in good agreement with the experimental data for excess (over the crystal state) thermodynamics of molecular glass formers. We suggest that the Kauzmann entropy crisis might be a signature of vanishing configurational entropy of a subset of degrees of freedom, multipolar rotations in our model. This scenario has observable consequences: (i) a dynamical crossover of the relaxation time and (ii) the fragility index defined by the ratio of the excess heat capacity and excess entropy at the glass transition. The Kauzmann temperature of vanishing configurational entropy and the corresponding glass transition temperature shift upward when the electric field is applied. The temperature shift scales quadratically with the field strength.

  6. Configurational entropy of polar glass formers and the effect of electric field on glass transition.

    Science.gov (United States)

    Matyushov, Dmitry V

    2016-07-21

    A model of low-temperature polar liquids is constructed that accounts for the configurational heat capacity, entropy, and the effect of a strong electric field on the glass transition. The model is based on the Padé-truncated perturbation expansions of the liquid state theory. Depending on parameters, it accommodates an ideal glass transition of vanishing configurational entropy and its avoidance, with a square-root divergent enumeration function at the point of its termination. A composite density-temperature parameter ρ(γ)/T, often used to represent combined pressure and temperature data, follows from the model. The theory is in good agreement with the experimental data for excess (over the crystal state) thermodynamics of molecular glass formers. We suggest that the Kauzmann entropy crisis might be a signature of vanishing configurational entropy of a subset of degrees of freedom, multipolar rotations in our model. This scenario has observable consequences: (i) a dynamical crossover of the relaxation time and (ii) the fragility index defined by the ratio of the excess heat capacity and excess entropy at the glass transition. The Kauzmann temperature of vanishing configurational entropy and the corresponding glass transition temperature shift upward when the electric field is applied. The temperature shift scales quadratically with the field strength.

  7. Hybrid Perovskite Phase Transition and Its Ionic, Electrical and Optical Properties

    Energy Technology Data Exchange (ETDEWEB)

    Hoque, Md Nadim Ferdous; Islam, Nazifah; Zhu, Kai; Fan, Zhaoyang

    2017-01-01

    Hybrid perovskite solar cells (PSCs) under normal operation will reach a temperature above ~ 60 °C, across the tetragonal-cubic structural phase transition of methylammonium lead iodide (MAPbI3). Whether the structural phase transition could result in dramatic changes of ionic, electrical and optical properties that may further impact the PSC performances should be studied. Herein, we report a structural phase transition temperature of MAPbI3thin film at ~ 55 °C, but a striking contrast occurred at ~ 45 °C in the ionic and electrical properties of MAPbI3due to a change of the ion activation energy from 0.7 eV to 0.5 eV. The optical properties exhibited no sharp transition except for the steady increase of the bandgap with temperature. It was also observed that the activation energy for ionic migration steadily increased with increased grain sizes, and reduction of the grain boundary density reduced the ionic migration.

  8. Analytical transition-matrix treatment of electric multipole polarizabilities of hydrogen-like atoms

    International Nuclear Information System (INIS)

    Kharchenko, V.F.

    2015-01-01

    The direct transition-matrix approach to the description of the electric polarization of the quantum bound system of particles is used to determine the electric multipole polarizabilities of the hydrogen-like atoms. It is shown that in the case of the bound system formed by the Coulomb interaction the corresponding inhomogeneous integral equation determining an off-shell scattering function, which consistently describes virtual multiple scattering, can be solved exactly analytically for all electric multipole polarizabilities. Our method allows to reproduce the known Dalgarno–Lewis formula for electric multipole polarizabilities of the hydrogen atom in the ground state and can also be applied to determine the polarizability of the atom in excited bound states. - Highlights: • A new description for electric polarization of hydrogen-like atoms. • Expression for multipole polarizabilities in terms of off-shell scattering functions. • Derivation of integral equation determining the off-shell scattering function. • Rigorous analytic solving the integral equations both for ground and excited states. • Study of contributions of virtual multiple scattering to electric polarizabilities

  9. Optical bus of centralized relay protection and automation system of ...

    African Journals Online (AJOL)

    The article deals with the system of information collection and transfer from a centralized relay protection and automation system for medium voltage electrical units based on a passive optical bus. The issues of electromagnetic compatibility of technical devices are also considered, and the intensity of electromagnetic ...

  10. The Wheels on the Bus Go “Buy Buy Buy”: School Bus Advertising Laws

    Science.gov (United States)

    2012-01-01

    School buses, a practical necessity for millions of children, are at the center of new efforts to raise revenue. School bus advertising laws bring public health and commercialization concerns to the school setting. In doing so, they potentially expose school districts to First Amendment lawsuits. I examined various school bus advertising bills and laws. I reviewed First Amendment “forum analysis” as applied in the transit and school settings to clarify how this legal test may affect school districts subject to such laws. I have made recommendations for school districts to enact appropriate policies to ensure that such advertising does not undermine public health and to enable the districts to maintain control over their property. PMID:22742065

  11. The wheels on the bus go "buy buy buy": school bus advertising laws.

    Science.gov (United States)

    Pomeranz, Jennifer L

    2012-09-01

    School buses, a practical necessity for millions of children, are at the center of new efforts to raise revenue. School bus advertising laws bring public health and commercialization concerns to the school setting. In doing so, they potentially expose school districts to First Amendment lawsuits. I examined various school bus advertising bills and laws. I reviewed First Amendment "forum analysis" as applied in the transit and school settings to clarify how this legal test may affect school districts subject to such laws. I have made recommendations for school districts to enact appropriate policies to ensure that such advertising does not undermine public health and to enable the districts to maintain control over their property.

  12. Lagrangian Hotspots of In-Use NOX Emissions from Transit Buses.

    Science.gov (United States)

    Kotz, Andrew J; Kittelson, David B; Northrop, William F

    2016-06-07

    In-use, spatiotemporal NOX emissions were measured from a conventional powertrain transit bus and a series electric hybrid bus over gradients of route kinetic intensity and ambient temperature. This paper introduces a new method for identifying NOX emissions hotspots along a bus route using high fidelity Lagrangian vehicle data to explore spatial interactions that may influence emissions production. Our study shows that the studied transit buses emit higher than regulated emissions because on-route operation does not accurately represent the range of engine operation tested according to regulatory standards. Using the Lagrangian hotspot detection, we demonstrate that NOX hotspots occurred at bus stops, during cold starts, on inclines, and for accelerations. On the selected routes, bus stops resulted in 3.3 times the route averaged emissions factor in grams/km without significant dependence on bus type or climate. The buses also emitted 2.3 times the route averaged NOX emissions factor at the beginning of each route due to cold selective catalytic reduction aftertreatment temperature. The Lagrangian hotspot detection technique demonstrated here could be employed in future connected vehicles empowered by advances in computational power, data storage capability, and improved sensor technology to optimize emissions as a function of spatial location.

  13. Driver rostering for bus transit companies

    NARCIS (Netherlands)

    Nurmi, K.; Kyngäs, J.; Post, Gerhard F.

    2011-01-01

    Staff scheduling has become increasingly important for both the public sector and private companies. Good rosters have many benefits for an organization, such as lower costs, more effective utilization of resources and fairer workloads and distribution of shifts. The process of constructing

  14. Scaling Laws in Chennai Bus Network

    OpenAIRE

    Chatterjee, Atanu; Ramadurai, Gitakrishnan

    2015-01-01

    In this paper, we study the structural properties of the complex bus network of Chennai. We formulate this extensive network structure by identifying each bus stop as a node, and a bus which stops at any two adjacent bus stops as an edge connecting the nodes. Rigorous statistical analysis of this data shows that the Chennai bus network displays small-world properties and a scale-free degree distribution with the power-law exponent, $\\gamma > 3$.

  15. Effect of electron correlation on the forced electric dipole transition probabilities in fsup(N) systems

    International Nuclear Information System (INIS)

    Jankowski, K.; Smentek-Mielczarek, L.

    1981-01-01

    Results of model studies of the impact of electron correlation on the forced electric dipole transition probabilities between states of the 4fsup(N) configuration are reported for the [ 3 P] 0 - [ 3 F] 4 , [ 3 H] 4 transitions in Pr 3+ : LaCl 3 and for [ 7 F] 0 - [ 5 D] 2 , [ 7 F] 1 - [ 5 D] 1 hypersensitive transitions in Eu 3+ : LaCl 3 . For the former system the correlation effects cause a modification of earlier results by 40-95 per cent, whereas for the latter the probability changes by as much as two orders of magnitude. The great changes found in the case of hypersensitive transitions suggest that electron correlation effects may belong to the most important factors determining the nature of these transitions. Several types of effective correlation operators are considered and their relative importance is discussed. The results indicate that intermediate configurations including g orbitals are very important for the description of correlation effects. (author)

  16. Evaluation of Urban Bus Transport Failure in Gujranwala City of Pakistan

    Directory of Open Access Journals (Sweden)

    MUHAMMAD WAQAR ASLAM

    2017-07-01

    Full Text Available This research work has evaluated the performance of urban public bus transport service operating in Gujranwala city of Pakistan. The assessment has been made in terms of financial viability, bus condition, operational performance and user perception. Based on the data requirements, various traffic/transport surveys were conducted including Passenger Boarding and Alighting Survey, Bus Count Survey, Bus Inspection Survey, Illegal Operations Survey and Public Transport User Interview Survey in consultation with concerned department/agencies. Field surveys were also conducted to get input from passengers and local people. Initial investigation informed that out of four operational bus routes, only two routes are profitable. The overall bus operation is running in loss (only 0.3% net profit. It has barely any profit for the bus operator against its investment thereby making the urban bus operation financially non-viable. The whole revenue flow is dependent on passenger ticketing revenue only. Around 35% of the buses are in poor condition with major issues of quality of tyres, no speedometer, worse condition of seats, floor and ceiling, and display of route. Illegal operation of Qingqis/Rickshaws (as para-transit mode along the bus routes is also decreasing the revenue by capturing the passenger volume. According to passenger opinion analysis, around 55% of the passenger are not satisfied with the service quality and prefer other modes of transport. Their major concerns are absence of facilities for disables and bus stops, bus seating and standing capacity, poor bus condition and pick pocketing. Collectively, these factors are contributing

  17. Superconducting link bus design for the accelerator project for upgrade of LHC

    International Nuclear Information System (INIS)

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.

    2011-01-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  18. The transition to the electric vehicle era; De transitie naar het tijdperk van de elektrische auto

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, J.

    2010-06-15

    The final transition from a fossil fuel driven transport system to an electricity driven transport system seems to be a fact. Every large car manufacturer has electric vehicles in its product range in the coming 6 to 24 months and more are expected to follow. Scientists and experts in the fields of electric driving see how this transition takes place in various stages: from hybrid cars to plug-in hybrids, to full-electric cars. The pace of this transition is mainly determined by the technical and institutional factors such as developments in battery technology and federal government policy. This transition will have a positive effect on climate, economy, national security and a wide range of other factors. The electric vehicle also offers opportunities in the field of smart and efficient use of energy by means of smart grid and vehicle to grid (V2G) technology. For now, the high cost price and low energy density of batteries (a decisive factor for the range) seem to constitute the largest obstacle to success. [Dutch] De definitieve overgang van een op fossiele brandstoffen naar een op elektriciteit gebaseerd transportsysteem lijkt een feit. Elke grote autofabrikant heeft in de komende 6 tot 24 maanden een elektrische auto in haar productaanbod en daar komen er naar verwachting steeds meer bij. Wetenschappers en experts op het gebied van elektrisch rijden zien deze overgang zich voltrekken in verschillende fases; van hybride auto's naar de plug-in hybrides, naar de volledig elektrische auto's. De snelheid waarmee deze overgang zal gaan plaatsvinden zal vooral bepaald worden door technische en institutionele factoren zoals ontwikkelingen in batterijtechnologie en het beleid van federale overheden. Deze overgang zal een positief effect hebben op het klimaat, de economie, de nationale veiligheid en een breed scala aan andere factoren. Ook biedt de elektrische auto mogelijkheden op het gebied van slim en efficient gebruik van energie door middel van smart

  19. Cost-related model for transit rates in electric power distribution networks

    International Nuclear Information System (INIS)

    Collstrand, F.

    1994-02-01

    The planned deregulation of the swedish electrical power market will require a new structure of the electrical energy rates. In this report different models of transit rates are studied. The report includes studies of literature and a proposal to a rate structure and is made specifically for Malmoe Energi AB. The differences between various methods of calculating the transfer cost are illustrated. Further, the build-up of the tariff structure and its base elements are discussed. The costs are divided on different categories of costumers and shows the cost for each customer. The new regulations should apply simultaneously to all networks, independent of the voltage level. The transit cost should be based on a number of basic elements: capital cost, operation and maintenance, losses, measuring and administration. Capital cost and operation and maintenance should be charged as power fees, the loss cost as an energy fee and the measuring and administration cost as a fixed fee. The customer bill should be split into two parts, one for the transit cost and one for the energy usage. 15 refs., 37 tabs., 6 figs

  20. Innovation and institutional change. The transition to a sustainable electricity system

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, P.S.

    2005-12-02

    relevant to the study of systems change and focuses on the way different theoretical streams deal with the institutional factor in fundamental changes of production and consumption systems (in short: systems change). Chapter three builds upon the theoretical reflections of the previous chapter and develops an analytical framework that structures the empirical part of the book. Main elements of the conceptual model used in the empirical chapters are introduced and explained. Chapter four - stability and transformation in the electricity system - analyses main changes that have taken place in the electricity system in the past three decades. The initial focus is on explaining the emergence of a range of alternative paths within the electricity system, varying from nuclear technology, to wind energy, biomass, cogeneration, and green electricity. Next the focus is on explaining relative success and failure of the paths taken within the context of the electricity and broader institutional arrangements for knowledge generation, economic exchange, policy and regulation, societal legitimacy. In-depth review of two relative successful paths takes place in two further chapters. Chapter five - the evolution of decentralized cogeneration - provides insight in how changes in the institutional setting, in connection with some other changes, can trigger a process of change where a previously disfavoured technological concept and design becomes more and more attractive and fundamentally alters basic beliefs and principles underlying the system. Chapter six - the emergence of green electricity - provides a more detailed assessment how the introduction of a new concept within the electricity system triggers changing interactions between institutional change at different levels which may offset a process of systems change. Chapter seven extends the analysis of past changes in the electricity system and utilise the insights for the development of potential transition paths towards a more

  1. Innovation and institutional change. The transition to a sustainable electricity system

    International Nuclear Information System (INIS)

    Hofman, P.S.

    2005-01-01

    relevant to the study of systems change and focuses on the way different theoretical streams deal with the institutional factor in fundamental changes of production and consumption systems (in short: systems change). Chapter three builds upon the theoretical reflections of the previous chapter and develops an analytical framework that structures the empirical part of the book. Main elements of the conceptual model used in the empirical chapters are introduced and explained. Chapter four - stability and transformation in the electricity system - analyses main changes that have taken place in the electricity system in the past three decades. The initial focus is on explaining the emergence of a range of alternative paths within the electricity system, varying from nuclear technology, to wind energy, biomass, cogeneration, and green electricity. Next the focus is on explaining relative success and failure of the paths taken within the context of the electricity and broader institutional arrangements for knowledge generation, economic exchange, policy and regulation, societal legitimacy. In-depth review of two relative successful paths takes place in two further chapters. Chapter five - the evolution of decentralized cogeneration - provides insight in how changes in the institutional setting, in connection with some other changes, can trigger a process of change where a previously disfavoured technological concept and design becomes more and more attractive and fundamentally alters basic beliefs and principles underlying the system. Chapter six - the emergence of green electricity - provides a more detailed assessment how the introduction of a new concept within the electricity system triggers changing interactions between institutional change at different levels which may offset a process of systems change. Chapter seven extends the analysis of past changes in the electricity system and utilise the insights for the development of potential transition paths towards a more

  2. Azure Dynamics transit connect : EV2010VE : upfitting to a battery electric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, B. [Azure Dynamics Corp., Toronto, ON (Canada)

    2010-07-01

    Transit Connect is a delivery vehicle brought to North America in 2010 that was initially released in Europe as part of Ford's global platform program. The stock layout includes the front engine; front wheel drive; fuel tank in rear; gasoline in North America; and diesel in Europe. This presentation described what Azure Dynamics Corporation did to improve the engine, transmission, energy storage, power steering, air conditioning, and generator. An overview of Transit Connect was provided. The presentation discussed design consideration, with particular reference to crash worthiness; durability; and total cost of implementation. Electrical harness and the total cost of implementation were also addressed. Other topics that were presented included the glider based design; a glider based design commonized platform; and additional design features. tabs., figs.

  3. The socio-technical transition of distributed electricity storage into future networks—System value and stakeholder views

    International Nuclear Information System (INIS)

    Grünewald, Philipp H.; Cockerill, Timothy T.; Contestabile, Marcello; Pearson, Peter J.G.

    2012-01-01

    Whole system models for the GB electricity system suggest that distributed electricity storage has the potential to significantly reduce the system integration cost for future system scenarios. From a policy perspective, this poses the question why this value should not be realised within existing market structures. Opinion among stakeholders is divided. Some believe that storage deployment constitutes a ‘special case’ in need of policy support. Others insist that markets can provide the necessary platform to negotiate contracts, which reward storage operators for the range of services they could provide. This paper seeks to inform this debate with a process of stakeholder engagement using a perspective informed by socio-technical transition literatures. This approach allows the identification of tensions among actors in the electricity system and of possibilities for co-evolution in the deployment of storage technologies during a transition towards a low carbon electricity system. It also draws attention to policy-related challenges of technology lock-in and path dependency resulting from poor alignment of incumbent regimes with the requirements for distributed electricity storage. - Highlights: ► Electricity storage is poorly aligned with existing regimes in the electricity system. ► Stakeholders perceive electricity storage as “somebody else's problem”. ► Combining stakeholder views and transition theory provides new insight. ► Transition from network to operational benefits poses regulatory challenge. ► Value aggregation made difficult due to institutional barriers.

  4. Observation of electric quadrupole X-ray transitions in muonic thallium, lead and bismuth

    CERN Document Server

    Schneuwly, H; Engfer, R; Jahnke, U; Kankeleit, E; Lindenberger, K H; Pearce, R M; Petitjean, C; Schellenberg, L; Schröder, W U; Walter, H K; Zehnder, A

    1972-01-01

    Electric quadrupole X-ray transitions (5g to 3d, 4f to 2p, and 3d to 1s) have been observed in muonic Tl, Pb and Bi. From the 3 to 1 transitions, energy splittings of the n=3 levels were deduced. From a comparison of the relative intensities of E1 and E2 transitions the population ratios 5g/5f, 4f/4d, and 3d/3p were deduced. These ratios are well reproduced by a cascade calculation assuming a statistical initial population at n=20, including K, L and M shell conversion. In the case of /sup 205/Tl discrepancies between the experimental and the calculated 3d-1s/3p-is intensity ratio can be explained by nuclear excitation. From the 3p/sub 3/2/ to 1s/sub 1/2/ intensity in /sup 209 /Bi one can deduce the ratio of the radiationless to the X-ray transition width and give limits for prompt neutron emission from the 3d level. (23 refs).

  5. The evolution of the electric power grid within the energy transition. Breakfast of 8 February 2017

    International Nuclear Information System (INIS)

    Prins, Katrien; ); Bendtsen, Bendt; ); Derdevet, Michel; Duerr, Matthias; Laffaye, Herve

    2017-01-01

    This document proposes a synthesis of contributions, questions and answers of a meeting gathering French and Danish representatives of political parties, electric utilities and European bodies which addressed issues related to the evolution of the electric power grid within a context of energy transition. Several issues have been addressed. First, the approach adopted by institutional actors like the European Commission and Parliament with a priority given to grid infrastructures to ensure interconnection between all member States, a financial support for the associated investments, and a European governance. Second, the approach adopted by operators in charge of networks, transport and distribution to face a change in the business model, an increasing financial burden, the issue of acceptability of works, future evolutions and innovations, and a closer collaboration

  6. An evaluation of the transitional Turkish electricity balancing and settlement market: Lessons for the future

    International Nuclear Information System (INIS)

    Camadan, Ercuement; Erten, Ibrahim Etem

    2011-01-01

    Balancing and settlement market is a crucial part of restructured Turkish electricity market. In this framework, the main purpose of this study is to examine whether the prices constituted in the transitional balancing and settlement market reflect the real cost of imbalances. Although it is observed that the prices are not powerful in indicating the real cost of imbalances, Turkey has the opportunity to form a well-functioning market within the context of planned new market structure. Turkey needs to define a proper roadmap reckoning the points mentioned in this paper to be able to achieve her objectives. (author)

  7. Percolation model of excess electrical noise in transition-edge sensors

    International Nuclear Information System (INIS)

    Lindeman, M.A.; Anderson, M.B.; Bandler, S.R.; Bilgri, N.; Chervenak, J.; Gwynne Crowder, S.; Fallows, S.; Figueroa-Feliciano, E.; Finkbeiner, F.; Iyomoto, N.; Kelley, R.; Kilbourne, C.A.; Lai, T.; Man, J.; McCammon, D.; Nelms, K.L.; Porter, F.S.; Rocks, L.E.; Saab, T.; Sadleir, J.; Vidugiris, G.

    2006-01-01

    We present a geometrical model to describe excess electrical noise in transition-edge sensors (TESs). In this model, a network of fluctuating resistors represents the complex dynamics inside a TES. The fluctuations can cause several resistors in series to become superconducting. Such events short out part of the TES and generate noise because much of the current percolates through low resistance paths. The model predicts that excess white noise increases with decreasing TES bias resistance (R/R N ) and that perpendicular zebra stripes reduce noise and alpha of the TES by reducing percolation

  8. Assessing the dynamic material criticality of infrastructure transitions: A case of low carbon electricity

    International Nuclear Information System (INIS)

    Roelich, Katy; Dawson, David A.; Purnell, Phil; Knoeri, Christof; Revell, Ruairi; Busch, Jonathan; Steinberger, Julia K.

    2014-01-01

    Highlights: • We present a method to analyse material criticality of infrastructure transitions. • Criticality is defined as the potential for, and exposure to, supply disruption. • Our method is dynamic reducing the probability of lock-in to at-risk technologies. • We show that supply disruption potential is reducing but exposure is increasing. - Abstract: Decarbonisation of existing infrastructure systems requires a dynamic roll-out of technology at an unprecedented scale. The potential disruption in supply of critical materials could endanger such a transition to low-carbon infrastructure and, by extension, compromise energy security more broadly because low carbon technologies are reliant on these materials in a way that fossil-fuelled energy infrastructure is not. Criticality is currently defined as the combination of the potential for supply disruption and the exposure of a system of interest to that disruption. We build on this definition and develop a dynamic approach to quantifying criticality, which monitors the change in criticality during the transition towards a low-carbon infrastructure goal. This allows us to assess the relative risk of different technology pathways to reach a particular goal and reduce the probability of being ‘locked in’ to currently attractive but potentially future-critical technologies. To demonstrate, we apply our method to criticality of the proposed UK electricity system transition, with a focus on neodymium. We anticipate that the supply disruption potential of neodymium will decrease by almost 30% by 2050; however, our results show the criticality of low carbon electricity production increases ninefold over this period, as a result of increasing exposure to neodymium-reliant technologies

  9. Implementation of a solar thermal electricity pilot plant (Concentrated Tower) of 1MW and introduction of a bus fleet of plug-in hybrids on the Ilha do Fundao, Rio de Janeiro, Brazil; Implementacao de uma planta piloto de heliotermia (Torre de Concentracao) de 1MW e introducao de uma frota de onibus hibridos plug-in na Ilha do Fundao

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Bruno Soares Moreira Cesar; Malagueta, Diego Cunha [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PPE/COPPE/UFRJ), RJ (Brazil). Programa de Planejamento Energetico

    2010-07-01

    The aim of this paper is to simulate a solar thermal electricity pilot plant at the Campus of the Federal University of Rio de Janeiro (UFRJ), at Fundao Island, which would generate part of the electricity demanded by the Technology Center (CT) of the UFRJ. Based on the electricity demand from UFRJ and the electric prices paid by the institution, this study proposes the construction of a 1MW Concentrated Solar Power (CSP) pilot plant and analyses the economical, energy and environmental viability of implementation of this plant, operating from 2015 to 2045. This CSP plant would cover a field of 0,01km{sup 2} and have a 30% of capacity factor. This study also evaluates the impact caused by the substitution of the current Campus internal bus fleet for plug-in hybrid electric buses. The current service is provided by Normandy, which operates 12 buses plus 1 backup. These new buses would be regularly partially recharged by the energy generated from CSP. All the simulations have been made with the RETScreen software, which simulated the operation of the CSP, the amount of electricity produced, the carbon emissions avoided, the acquisition and implementation of the plug-in hybrid electric bus fleet and the cash flow. Six scenarios generated were, namely A1, B1, C1 (all for lower costs for the CSP plants) and A2, B2, C2 (for higher costs). For a social discount rate around 8% and along 30 years, only the A1, C1 and C2 scenarios showed a non-negative cash flow. Also, the emissions avoided were around 222 tCO{sub 2}/yr (or 6.660 tCO{sub 2} over 30 years) in the A1 and A2 scenarios, and around 550 tCO{sub 2}/yr (or 16.512 tCO{sub 2} over 30 years) in all others scenarios. (author)

  10. A Control Strategy for Mode Transition with Gear Shifting in a Plug-In Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Kyuhyun Sim

    2017-07-01

    Full Text Available The mode transition from electric propulsion mode to hybrid propulsion mode is important with regard to the power management strategy of plug-in hybrid electric vehicles (PHEVs. This is because mode transitions can occur frequently depending on the power management strategies and driving cycles, and because inadequate mode transitions worsen the fuel efficiency and drivability. A pre-transmission parallel PHEV uses a clutch between the internal combustion engine (ICE and the electric motor (EM to connect or disconnect the power source of the ICE for a mode transition. The mode transition requires additional energy consumption for clutch speed synchronization, and is accompanied by a drivetrain shock due to clutch engagement. This paper proposes a control strategy for the mode transition with gear-shifting to resolve the problems of energy consumption and drivetrain shock. Through the development of a PHEV performance simulator, we analyze the mode transition characteristics and propose a control strategy considering the vehicle acceleration and gear state. The control strategy reduces the duration required for the mode transition by moving the start time of the mode transition. This helps to improve energy efficiency while maintaining adequate drivability.

  11. Dynamic imaging in electrical impedance tomography of the human chest with online transition matrix identification.

    Science.gov (United States)

    Moura, Fernando Silva; Aya, Julio Cesar Ceballos; Fleury, Agenor Toledo; Amato, Marcelo Britto Passos; Lima, Raul Gonzalez

    2010-02-01

    One of the electrical impedance tomography objectives is to estimate the electrical resistivity distribution in a domain based only on electrical potential measurements at its boundary generated by an imposed electrical current distribution into the boundary. One of the methods used in dynamic estimation is the Kalman filter. In biomedical applications, the random walk model is frequently used as evolution model and, under this conditions, poor tracking ability of the extended Kalman filter (EKF) is achieved. An analytically developed evolution model is not feasible at this moment. The paper investigates the identification of the evolution model in parallel to the EKF and updating the evolution model with certain periodicity. The evolution model transition matrix is identified using the history of the estimated resistivity distribution obtained by a sensitivity matrix based algorithm and a Newton-Raphson algorithm. To numerically identify the linear evolution model, the Ibrahim time-domain method is used. The investigation is performed by numerical simulations of a domain with time-varying resistivity and by experimental data collected from the boundary of a human chest during normal breathing. The obtained dynamic resistivity values lie within the expected values for the tissues of a human chest. The EKF results suggest that the tracking ability is significantly improved with this approach.

  12. Spontaneous transition rates for electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions for He-like calcium and sulfur ions

    International Nuclear Information System (INIS)

    Kingston, A.E.; Norrington, P.H.; Boone, A.W.

    2002-01-01

    The spontaneous decay rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s 2 , 1s2 l and 1s3 l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wavefunctions. One set of wavefunctions was generated using the fully relativistic GRASP code and the other was obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Δn=1 or 2 transitions. For Δn=0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies. (author)

  13. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems.

    Science.gov (United States)

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a "normal" state where the motors' mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a "stalled" state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors' mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

  14. Basic concepts for designing renewable electricity support aiming at a full-scale transition by 2050

    International Nuclear Information System (INIS)

    Verbruggen, Aviel; Lauber, Volkmar

    2009-01-01

    Renewable electricity supply is a crucial factor in the realization of a low-carbon energy economy. The understanding is growing that a full turn-over of the electricity sectors by 2050 is an elementary condition for avoiding global average temperature increase beyond 2 C. This article adopts such full transition as Europe's target when designing renewable energy policy. An immediate corollary is that phasing-in unprecedented energy efficiency and renewable generation must be paralleled by phasing-out non-sustainable fossil fuel and nuclear power technologies. The double phasing programme assigns novel meaning to nearby target settings for renewable power as share of total power consumption. It requires organizing in the medium term EU-wide markets for green power, a highly demanding task in the present context of poorly functional markets in brown power. The EU Commission's 2007/2008 proposals of expanding tradable certificates markets were not based on solid analysis of past experiences and future necessities. The keystone of sound policies on renewable electricity development is a detailed scientific differentiation and qualification of renewable electricity sources and technologies, for measuring the huge diversity in the field. We provide but structuring concepts about such qualification, because implementation requires extensive research resources. Support for renewable electricity development is organized via feed-in prices or premiums, and via quota obligations connected to tradable green certificates. Green certificates are dependent on physical generated renewable power, but separable and no joint products. Contrary to conventional wisdom we argue their separation in cost analysis but firm linking during trade. A few graphs illustrate the importance of assigning qualities to different renewable power sources/technologies. Feed-in systems based on an acceptable qualification perform generally better than certificate markets imposing uniform approaches on a

  15. Strategic Transit Automation Research Plan

    Science.gov (United States)

    2018-01-01

    Transit bus automation could deliver many potential benefits, but transit agencies need additional research and policy guidance to make informed deployment decisions. Although funding and policy constraints may play a role, there is also a reasonable...

  16. SnTe field effect transistors and the anomalous electrical response of structural phase transition

    International Nuclear Information System (INIS)

    Li, Haitao; Zhu, Hao; Yuan, Hui; Li, Qiliang; You, Lin; Kopanski, Joseph J.; Richter, Curt A.; Zhao, Erhai

    2014-01-01

    SnTe is a conventional thermoelectric material and has been newly found to be a topological crystalline insulator. In this work, back-gate SnTe field-effect transistors have been fabricated and fully characterized. The devices exhibit n-type transistor behaviors with excellent current-voltage characteristics and large on/off ratio (>10 6 ). The device threshold voltage, conductance, mobility, and subthreshold swing have been studied and compared at different temperatures. It is found that the subthreshold swings as a function of temperature have an apparent response to the SnTe phase transition between cubic and rhombohedral structures at 110 K. The abnormal and rapid increase in subthreshold swing around the phase transition temperature may be due to the soft phonon/structure change which causes the large increase in SnTe dielectric constant. Such an interesting and remarkable electrical response to phase transition at different temperatures makes the small SnTe transistor attractive for various electronic devices.

  17. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2016

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jeffers, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-01

    This report, published annually, summarizes the progress of fuel cell electric bus development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of results from evaluations performed by the National Renewable Energy Laboratory. Funding for this effort is provided by the U.S. Department of Energy's Fuel Cell Technologies Office within the Office of Energy Efficiency and Renewable Energy and by the U.S. Department of Transportation's Federal Transit Administration. The 2016 summary results primarily focus on the most recent year for each demonstration, from August 2015 through July 2016. The results for these buses account for more than 550,000 miles traveled and 59,500 hours of fuel cell power system operation. The primary results presented in the report are from three demonstrations of two different fuel-cell-dominant bus designs: Zero Emission Bay Area Demonstration Group led by Alameda-Contra Costa Transit District (AC Transit) in California; American Fuel Cell Bus Project at SunLine Transit Agency in California; and American Fuel Cell Bus Project at the University of California at Irvine.

  18. School Bus Accidents and Driver Age.

    Science.gov (United States)

    McMichael, Judith

    The study examines the rates and types of school bus accidents according to the age of the school bus driver. Accident rates in North Carolina for the school year 1971-72 were analyzed using three sources of data: accident reports, driver and mileage data, and questionnaires administered to a sample of school bus drivers. Data were obtained on…

  19. Phase-field model of insulator-to-metal transition in VO2 under an electric field

    Science.gov (United States)

    Shi, Yin; Chen, Long-Qing

    2018-05-01

    The roles of an electric field and electronic doping in insulator-to-metal transitions are still not well understood. Here we formulated a phase-field model of insulator-to-metal transitions by taking into account both structural and electronic instabilities as well as free electrons and holes in VO2, a strongly correlated transition-metal oxide. Our phase-field simulations demonstrate that in a VO2 slab under a uniform electric field, an abrupt universal resistive transition occurs inside the supercooling region, in sharp contrast to the conventional Landau-Zener smooth electric breakdown. We also show that hole doping may decouple the structural and electronic phase transitions in VO2, leading to a metastable metallic monoclinic phase which could be stabilized through a geometrical confinement and the size effect. This work provides a general mesoscale thermodynamic framework for understanding the influences of electric field, electronic doping, and stress and strain on insulator-to-metal transitions and the corresponding mesoscale domain structure evolution in VO2 and related strongly correlated systems.

  20. Bus transport in Greater Manchester

    DEFF Research Database (Denmark)

    Sørensen, Claus Hedegaard; Gudmundsson, Henrik

    component regards the organisation of public bus transport at the local level. This involves the deregulation and privatisation reforms introduced by the Conservative Government from 1986 onwards, as well as the ‘partnerships’ and other new instruments introduced by the Labour Government in the Transport...

  1. Pybus - A Python Software Bus

    International Nuclear Information System (INIS)

    Lavrijsen, Wim T.L.P.

    2004-01-01

    A software bus, just like its hardware equivalent, allows for the discovery, installation, configuration, loading, unloading, and run-time replacement of software components, as well as channeling of inter-component communication. Python, a popular open-source programming language, encourages a modular design on software written in it, but it offers little or no component functionality. However, the language and its interpreter provide sufficient hooks to implement a thin, integral layer of component support. This functionality can be presented to the developer in the form of a module, making it very easy to use. This paper describes a Pythonmodule, PyBus, with which the concept of a ''software bus'' can be realized in Python. It demonstrates, within the context of the ATLAS software framework Athena, how PyBus can be used for the installation and (run-time) configuration of software, not necessarily Python modules, from a Python application in a way that is transparent to the end-user

  2. Challenges to China's transition to a low carbon electricity system

    Energy Technology Data Exchange (ETDEWEB)

    Kahrl, Fredrich, E-mail: fkahrl@berkeley.edu [Energy and Resources Group, University of California, Berkeley, 310 Barrows Hall, Berkeley, CA 94720 (United States); Williams, Jim [Energy and Environmental Economics, Inc., 101 Montgomery Street, 16th Floor, San Francisco, CA 94104 (United States); Monterey Institute of International Studies, 460 Pierce Street, Monterey, CA 93940 (United States); Ding Jianhua [Energy and Environmental Economics, Inc., 101 Montgomery Street, 16th Floor, San Francisco, CA 94104 (United States); Hu Junfeng [School of Economics and Business Administration, North China Electric Power University, Beijing 102206 (China)

    2011-07-15

    We examine the challenges to China's transition to a low carbon electricity system, in which renewable energy would play a significant role. China's electricity system currently lacks the flexibility in planning, operations, and pricing to respond to conflicting pressures from demand growth, rising costs, and environmental mandates in a way that simultaneously maintains reliability, decarbonizes the system, and keeps prices within acceptable bounds. Greater flexibility crucially requires the ability to more systematically and transparently manage and allocate costs. This will require re-orientating sector institutions still rooted in central planning, and strengthening independent regulation. Some of the necessary changes require fundamental political and legal reforms beyond the scope of energy policy. However, the system's flexibility can still be increased through the development of traditional planning and regulatory tools and approaches, such as an avoided cost basis for energy efficiency investments, more integrated planning to improve the coordination of generation, transmission, and demand-side investments, and a transparent ratemaking process. The judicious application of OECD electricity sector experience and skills can support these developments. - Research Highlights: > China's electricity system currently lacks the flexibility to integrate renewables and reduce CO{sub 2} emissions on a large scale at an acceptable cost and level of reliability. > The challenges to increased flexibility are more institutional than technological. > Chinese government agencies need new approaches to basic power system planning and ratemaking. > OECD countries can help address these challenges through the transfer of 'soft' technologies.

  3. Effect of electric field on the oscillator strength and cross-section for intersubband transition in a semiconductor quantum ring

    International Nuclear Information System (INIS)

    Bhattacharyya, S; Das, N R

    2012-01-01

    In this paper, we study the oscillator strength and cross-section for intersubband optical transition in an n-type semiconductor quantum ring of cylindrical symmetry in the presence of an electric field perpendicular to the plane of the ring. The analysis is done considering Kane-type band non-parabolicity of the semiconductor and assuming that the polarization of the incident radiation is along the axis of the ring. The results show that the oscillator strength decreases and the transition energy increases with the electric field. The assumption of a parabolic band leads to an overestimation of the oscillator strength. The effects of the electric field, band non-parabolicity and relaxation time on absorption cross-section for intersubband transition in a semiconductor quantum ring are also shown. (paper)

  4. Shelter from the Storm: Optimizing Distribution of Bus Stop Shelters in Los Angeles

    OpenAIRE

    Law, Philip; Taylor, Brian D.

    2010-01-01

    The functions of bus stop shelters and factors affecting their placement at stops in transit systems are analyzed. Drawing on information from a variety of sources, current shelter placement policy in Los Angeles was found to be guided principally by the revenue-generating potential of shelter advertisements, secondarily by political concerns over geographic equity, and only peripherally on the basis of bus stop use. Using data on shelter and stop locations, boardings, and headways, a methodo...

  5. Optimal bus temperature for thermal comfort during a cool day.

    Science.gov (United States)

    Velt, K B; Daanen, H A M

    2017-07-01

    A challenge for electric buses is to minimize heating and cooling power to maximally extend the driving range, but still provide sufficient thermal comfort for the driver and passengers. Therefore, we investigated the thermal sensation (TS) and thermal comfort (TC) of passengers in buses during a cool day (temperature 13.4 ± 0.5 °C, relative humidity (RH) 60 ± 5.8%) typical for the Dutch temperate maritime climate. 28 Males and 72 females rated TS and TC and gave information on age, stature, body weight and worn garments. The temperature in the bus of 22.5 ± 1.1 °C and RH of 59.9 ± 5.8% corresponded to a slightly warm feeling (TS = 0.85 ± 1.06) and TC of 0.39 ± 0.65. TS related significantly to bus temperature, clothing insulation and age. Linear regression based on these parameters showed that the temperature in the bus corresponding to TC = 0 and TS = 0 would have been 20.9 ± 0.6 °C. In conclusion, a 1.6 °C lower bus temperature during the investigated cool day probably would have led to less thermal discomfort and energy savings of electrical busses. The methodology to relate climatic measurements to subjective assessments is currently employed in a wider climatic range and may prove to be useful to find a better balance between thermal comfort and energy savings of the bus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Specific heat and electric conductivity of zirconium alloy with 2,5 mass% niobium in the range of phase transitions

    International Nuclear Information System (INIS)

    Roshchupkin, V.V.; Pokrasin, M.A.; Chernov, A.I.; Semashko, N.A.

    1996-01-01

    Experimental investigation of specific heat and electric resistance of zirconium alloy with 2.5 mass% niobium in the range of phase transitions was conducted, using adiabatic calorimeter of original design, characterized by high sensitivity, efficiency and high accuracy. It was revealed that temperature dependence of specific heat was characterized by anomalous growth at 590 deg C, related with (α+β Nb )→(α+β Zr )-transition, and at 810 deg -related with (α+β Zr )→β Zr - transition. Temperature dependence of electric resistance was specific in the region of α+β Zr →β Zr phase transition. It was established that revealed anomalies were connected with high oxygen absorption at high temperatures. 11 refs., 1 fig., 1 tab

  7. Neoclassical transport, poloidal rotation and radial electric field at the L-H transition

    International Nuclear Information System (INIS)

    Minardi, E.; Gervasini, G.; Lazzaro, E.

    1993-01-01

    The transition to a high confinement regime in tokamaks operating with a magnetic divertor configuration is accompanied by the strong steepening of the edge temperature profile and the onset of a large positive poloidal mass rotation associated with a negative radial electric field. The latter phenomena are signatures of a neoclassical transport mechanism. We address the question of establishing whether neoclassical transport is indeed sufficient to establish high edge gradients and drive poloidal rotation under strong auxiliary heating. The heat transport equation is solved numerically in a narrow edge layer interfaced to the plasma body through heat flux continuity, but allowing for heat conductivity discontinuity. The results compared with recent experimental measurements support the assumption that a highly sheared neoclassical poloidal velocity profile can suppress the anomalous part of the heat transport, and that the neoclassical residual transport, characterizes the plasma behaviour at the edge during H modes. (author) 3 refs., 4 figs

  8. Dynamic behavior associated with electric field transitions in CHS Heliotron/Torsatron

    International Nuclear Information System (INIS)

    Fujisawa, A.; Iguchi, H.; Lee, S.

    2001-01-01

    A new kind of oscillatory steady state is discovered in observation of potential with a heavy ion beam probe in Compact Helical System Heliotron/Torsatron. Bulk plasma parameters, such as electron temperature and density profile, change being synchronized with the pulsation of potential. The phenomenon can be regarded as successive transitions between two bifurcative states of the plasma. The pulsation can be self-sustained and create a dynamic steady state in low density plasma with electron cyclotron heating. The cause of phenomenon is associated with the bifurcation nature of radial electric field, that is inherent with toroidal helical plasmas. This paper presents two examples of the phenomenon in different density regimes. Dependence of pulsation characteristics on several parameters is described. The bifurcation property predicted by a neoclassical theory is presented for comparison with the experimental observations. (author)

  9. Electric power is not the same power. Why the energy transition can not succeed

    International Nuclear Information System (INIS)

    Limburg, Michael; Mueller, Fred F.

    2015-01-01

    The energy transition - the conversion of our power supply to so-called ''Renewable Energy'' - will lead to disaster, economically as well as technically. Although the concept is not technically feasible, more than 500 billion Euros were spent for this purpose already. This money our economy will miss bitterly when it is needed it to go, sweep up the future shambles. Here explain two recognized experts why. ''The book, 'electric power is not the same power' pulled himself together again on a colossal effort. It dissects technically brilliant with the tools of logic, scientific reasoning a fatal mental aberration.''- Arnold Vaatz MP. [de

  10. Analysis of robustness of urban bus network

    Science.gov (United States)

    Tao, Ren; Yi-Fan, Wang; Miao-Miao, Liu; Yan-Jie, Xu

    2016-02-01

    In this paper, the invulnerability and cascade failures are discussed for the urban bus network. Firstly, three static models(bus stop network, bus transfer network, and bus line network) are used to analyse the structure and invulnerability of urban bus network in order to understand the features of bus network comprehensively. Secondly, a new way is proposed to study the invulnerability of urban bus network by modelling two layered networks, i.e., the bus stop-line network and the bus line-transfer network and then the interactions between different models are analysed. Finally, by modelling a new layered network which can reflect the dynamic passenger flows, the cascade failures are discussed. Then a new load redistribution method is proposed to study the robustness of dynamic traffic. In this paper, the bus network of Shenyang City which is one of the biggest cities in China, is taken as a simulation example. In addition, some suggestions are given to improve the urban bus network and provide emergency strategies when traffic congestion occurs according to the numerical simulation results. Project supported by the National Natural Science Foundation of China (Grant Nos. 61473073, 61374178, 61104074, and 61203329), the Fundamental Research Funds for the Central Universities (Grant Nos. N130417006, L1517004), and the Program for Liaoning Excellent Talents in University (Grant No. LJQ2014028).

  11. Band mixing and electric monopole contribution in 2sub(. gamma. ). -->. 2sub(g) transition in /sup 168/Er

    Energy Technology Data Exchange (ETDEWEB)

    Sahota, H S; Hasiza, M L; Mittal, R [Punjabi Univ., Patiala (India). Dept. of Physics

    1976-06-01

    The 2sub(..gamma..)..-->..2sub(g) transition in /sup 168/Er has been examined for the presence of electric monopole contribution. The experimental E0/E2 reduced transition probabilities and monopole matrix element have been found to be somewhat larger than the theoretical predictions of the Bohr-Mottelson model but the ratio rhosup(2)/X has been found to agree well with the theoretical value. The band mixing parameters have also been evaluated and found to be sizeable.

  12. Transition between vortex rings and MAP solutions for electrically charged magnetic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Khai-Ming; Soltanian, Amin; Teh, Rosy [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2014-03-05

    We consider the bifurcation and transition of axially symmetric monopole-antimonopole pair (MAP) and vortex ring solutions in the presence of electric charge for the SU(2) Yang-Mills-Higgs field theory. Here we investigate the properties of MAP/vortex ring solutions with n = 3,η = 0.65, for different Higgs field strength λ. For λ < 4.93, there is only one fundamental branch of vortex ring solution, but at the critical value of λ{sub b} = 4.93, branching happens and 2 sets of new solutions appeared. The new branch with less energy is a full MAP solution while the branch with higher energy contains MAP at the beginning and separation between poles of MAP on the z-axis reduces gradually and at another critical value of λ{sub t} = 14.852, they merge together at z = 0. Beyond this point the solutions change to the vortex ring solutions and a transitions between MAP and vortex ring solutions happens at this branch.

  13. Soil Structure Evaluation Across Geologic Transition Zones Using 2D Electrical Resistivity Imaging Technique

    Directory of Open Access Journals (Sweden)

    Geraldine C Anukwu

    2017-06-01

    Full Text Available This study utilizes the electrical resistivity values obtained using 2-D Electrical resistivity imaging (ERI technique to evaluate the subsurface lithology across different geological units. The primary objective was to determine the effect of subsurface lithology on the integrity of a road pavement, which had developed cracks and potholes at various locations. The dipole-dipole configuration was utilized and a total of nine traverses were established in the study area, whose geology cuts across both the basement and sedimentary complexes. The inverted resistivity section obtained showed significant variation in resistivity along established traverses and also across the different rock units, with the resistivity value ranging from about 4 ohm-m to greater than 7000 ohm- m. The lithology as interpreted from the resistivity section revealed the presence topsoil, clay, sandy clay, sand, sand stones/basement rocks, with varying vertical and horizontal arrangements to a depth of 40m. Results suggest that the geologic sequence and structure might have contributed to the observed pavement failure. The capability of the 2D ERI as an imaging tool is observed, especially across the transition zones as depicted in this study. The study further stressed the ability of this technique if properly designed and implemented, to be capable of providing a wealth of information that could complement other traditional geotechnical and geologic techniques.

  14. Solar Electricity and Solar Fuels: Status and Perspectives in the Context of the Energy Transition.

    Science.gov (United States)

    Armaroli, Nicola; Balzani, Vincenzo

    2016-01-04

    The energy transition from fossil fuels to renewables is already ongoing, but it will be a long and difficult process because the energy system is a gigantic and complex machine. Key renewable energy production data show the remarkable growth of solar electricity technologies and indicate that crystalline silicon photovoltaics (PV) and wind turbines are the workhorses of the first wave of renewable energy deployment on the TW scale around the globe. The other PV alternatives (e.g., copper/indium/gallium/selenide (CIGS) or CdTe), along with other less mature options, are critically analyzed. As far as fuels are concerned, the situation is significantly more complex because making chemicals with sunshine is far more complicated than generating electric current. The prime solar artificial fuel is molecular hydrogen, which is characterized by an excellent combination of chemical and physical properties. The routes to make it from solar energy (photoelectrochemical cells (PEC), dye-sensitized photoelectrochemical cells (DSPEC), PV electrolyzers) and then synthetic liquid fuels are presented, with discussion on economic aspects. The interconversion between electricity and hydrogen, two energy carriers directly produced by sunlight, will be a key tool to distribute renewable energies with the highest flexibility. The discussion takes into account two concepts that are often overlooked: the energy return on investment (EROI) and the limited availability of natural resources-particularly minerals-which are needed to manufacture energy converters and storage devices on a multi-TW scale. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. HEV Test Bench Based on CAN Bus Sensor Communication

    Directory of Open Access Journals (Sweden)

    Shupeng ZHAO

    2014-02-01

    Full Text Available The HEV test bench based on Controller Area Network bus was studied and developed. Control system of HEV power test bench used the CAN bus technology. The application of CAN bus technology on control system development has opened up a new research direction for domestic automobile experimental platform. The HEV power control system development work was completed, including power master controller, electric throttle controller, driving simulation platform, CAN2.0 B communication protocol procedures for formulation, CAN communication monitoring system, the simulation model based on MATLAB code automatic generation technology research, etc. Maximum absorption power of the test bench is 90 kW, the test bench top speed is 6000 r/min, the CAN communication data baud rate is 10~500 k, the conventional electric measurement parameter part precision satisfies the requirement of development of HEV. On the HEV test bench the result of regenerative braking experiment shows that the result got by the test bench was closer to the results got by outdoor road test. And the fuel consumption experiment test results show that the HEV fuel consumption and the charge-discharge character are in linear relationship. The establishment of the test platform for the evaluation of the development of hybrid electric vehicle and power provides physical simulation and test platform.

  16. Hybrid Turbine Electric Vehicle

    Science.gov (United States)

    Viterna, Larry A.

    1997-01-01

    Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

  17. Avionic Data Bus Integration Technology

    Science.gov (United States)

    1991-12-01

    address the hardware-software interaction between a digital data bus and an avionic system. Very Large Scale Integration (VLSI) ICs and multiversion ...the SCP. In 1984, the Sperry Corporation developed a fault tolerant system which employed multiversion programming, voting, and monitoring for error... MULTIVERSION PROGRAMMING. N-version programming. 226 N-VERSION PROGRAMMING. The independent coding of a number, N, of redundant computer programs that

  18. New TPG bus route 28

    CERN Multimedia

    2003-01-01

    Geneva's Public Transport services (TPG) have recently inaugurated a new bus line 28, connecting the La Tour Hospital in Meyrin to the international organisations in Geneva, via the airport. All signs associated with this route will be yellow in colour. Timetables and route details can be found at http://www.tpg.ch. Relations with the Host States Service http://www.cern.ch/relations/ Tel. 72848

  19. Model validation for radial electric field excitation during L-H transition in JFT-2M tokamak

    Science.gov (United States)

    Kobayashi, T.; Itoh, K.; Ido, T.; Kamiya, K.; Itoh, S.-I.; Miura, Y.; Nagashima, Y.; Fujisawa, A.; Inagaki, S.; Ida, K.; Hoshino, K.

    2017-07-01

    In this paper, we elaborate the electric field excitation mechanism during the L-H transition in the JFT-2M tokamak. Using time derivative of the Poisson’s equation, models of the radial electric field excitation is examined. The sum of the loss-cone loss current and the neoclassical bulk viscosity current is found to behave as the experimentally evaluated radial current that excites the radial electric field. The turbulent Reynolds stress only plays a minor role. The wave convection current that produces a negative current at the edge can be important to explain the ambipolar condition in the L-mode.

  20. Traveling by Bus Instead of Car on Urban Major Roads: Safety Benefits for Vehicle Occupants, Pedestrians, and Cyclists.

    Science.gov (United States)

    Morency, Patrick; Strauss, Jillian; Pépin, Félix; Tessier, François; Grondines, Jocelyn

    2018-04-01

    Some studies have estimated fatality and injury rates for bus occupants, but data was aggregated at the country level and made no distinction between bus types. Also, injured pedestrians and cyclists, as a result of bus travel, were overlooked. We compared injury rates for car and city bus occupants on specific urban major roads, as well as the cyclist and pedestrian injuries associated with car and bus travel. We selected ten bus routes along major urban arterials (in Montreal, Canada). Passenger-kilometers traveled were estimated from vehicle counts at intersections (2002-2010) and from bus passenger counts (2008). Police accident reports (2001-2010) provided injury data for all modes. Injury rates associated with car and bus travel were calculated for vehicle occupants, pedestrians, and cyclists. Injury rate ratios were also computed. The safety benefits of bus travel, defined as the number of vehicle occupant, cyclist, and pedestrian injuries saved, were estimated for each route. Overall, for all ten routes, the ratio between car and bus occupant injury rates is 3.7 (95% CI [3.4, 4.0]). The rates of pedestrian and cyclist injuries per hundred million passenger-kilometers are also significantly greater for car travel than that for bus travel: 4.1 (95% CI [3.5, 4.9]) times greater for pedestrian injuries; 5.3 (95% CI [3.8, 7.6]) times greater for cyclist injuries. Similar results were observed for fatally and severely injured vehicle occupants, cyclists, and pedestrians. At the route level, the safety benefits of bus travel increase with the difference in injury rate associated with car and bus travel but also with the amount of passenger-kilometers by bus. Results show that city bus is a safer mode than car, for vehicle occupants but also for cyclists and pedestrians traveling along these bus routes. The safety benefits of bus travel greatly vary across urban routes; this spatial variation is most likely linked to environmental factors. Understanding the

  1. Designing Sustainable Public Transportation: Integrated Optimization of Bus Speed and Holding Time in a Connected Vehicle Environment

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2016-11-01

    Full Text Available Developing public transportation and giving priority to buses is a feasible solution for improving the level of public transportation service, which facilitates congestion alleviation and prevention, and contributes to urban development and city sustainability. This paper presents a novel bus operation control strategy including both holding control and speed control to improve the level of service of transit systems within a connected vehicle environment. Most previous work focuses on optimization of signal timing to decrease the bus signal delay by assuming that holding control is not applied; the speed of buses is given as a constant input and the acceleration and deceleration processes of buses can be neglected. This paper explores the benefits of a bus operation control strategy to minimize the total cost, which includes bus signal delay, bus holding delay, bus travel delay, acceleration cost due to frequent stops and intense driving. A set of formulations are developed to explicitly capture the interaction between bus holding control and speed control. Experimental analysisand simulation tests have shown that the proposed integrated operational model outperforms the traditional control, speed control only, or holding control only strategies in terms of reducing the total cost of buses. The sensitivity analysis has further demonstrated the potential effectiveness of the proposed approach to be applied in a real-time bus operation control system under different levels of traffic demand, bus stop locations, and speed limits.

  2. Bus Stops and Pedestrian-Motor Vehicle Collisions in Lima, Peru: A Matched Case-Control Study

    Science.gov (United States)

    Quistberg, D. Alex; Koepsell, Thomas D.; Johnston, Brian D.; Boyle, Linda Ng; Miranda, J. Jaime; Ebel, Beth E.

    2015-01-01

    Objective To evaluate the relationship between bus stop characteristics and pedestrian-motor vehicle collisions. Design Matched case-control study where the units of study were pedestrian crossing. Setting Random sample of 11 police commissaries in Lima, Peru. Data collection occurred from February, 2011 to September, 2011. Participants 97 intersection cases representing 1,134 collisions and 40 mid-block cases representing 469 collisions that occurred between October, 2010 and January, 2011 and their matched controls. Main Exposures Presence of a bus stop and specific bus stop characteristics. Main Outcome Occurrence of a pedestrian-motor vehicle collision. Results Intersections with bus stops were three times more likely to have a pedestrian-vehicle collision (OR 3.28, 95% CI 1.53-7.03), relative to intersections without bus stops. Both formal and informal bus stops were associated with a higher odds of a collision at intersections (OR 6.23, 95% CI 1.76-22.0 and OR 2.98, 1.37-6.49). At mid-block sites, bus stops on a bus-dedicated transit lane were also associated with collision risk (OR 2.36, 95% CI 1.02-5.42). All bus stops were located prior to the intersection, contrary to practices in most high income countries. Conclusions In urban Lima, the presence of a bus stop was associated with a three-fold increase in risk of a pedestrian collision. The highly competitive environment among bus companies may provide an economic incentive for risky practices such as dropping off passengers in the middle of traffic and jockeying for position with other buses. Bus stop placement should be considered to improve pedestrian safety. PMID:24357516

  3. Iterated Local Search Algorithm with Strategic Oscillation for School Bus Routing Problem with Bus Stop Selection

    Directory of Open Access Journals (Sweden)

    Mohammad Saied Fallah Niasar

    2017-02-01

    Full Text Available he school bus routing problem (SBRP represents a variant of the well-known vehicle routing problem. The main goal of this study is to pick up students allocated to some bus stops and generate routes, including the selected stops, in order to carry students to school. In this paper, we have proposed a simple but effective metaheuristic approach that employs two features: first, it utilizes large neighborhood structures for a deeper exploration of the search space; second, the proposed heuristic executes an efficient transition between the feasible and infeasible portions of the search space. Exploration of the infeasible area is controlled by a dynamic penalty function to convert the unfeasible solution into a feasible one. Two metaheuristics, called N-ILS (a variant of the Nearest Neighbourhood with Iterated Local Search algorithm and I-ILS (a variant of Insertion with Iterated Local Search algorithm are proposed to solve SBRP. Our experimental procedure is based on the two data sets. The results show that N-ILS is able to obtain better solutions in shorter computing times. Additionally, N-ILS appears to be very competitive in comparison with the best existing metaheuristics suggested for SBRP

  4. Evaluating the Impacts of Bus Fare on Social Equity Based on IC Card Data in China

    Directory of Open Access Journals (Sweden)

    Shaowu Cheng

    2016-10-01

    Full Text Available Bus fare equity has attracted significant attention in China in the past few years. Compared with developed countries, China’s intelligent transportation systems are in their infancy, with immature bus fare policies being used in many public transit systems. The methods used for evaluating public transit fare equity in developed countries compare different fare policies based on rich data and cannot be directly applied in developing countries like China. In this paper, we present a method that uses IC card data, bus-mounted GPS data, and relevant statistical yearbook data to evaluate the equity of flat bus fare. The method ranks the factors that influence the impacts of bus fare on social equity for different passenger groups and indicates that trip distance and passenger boarding time are the two primary factors for bus fare equity from a resource allocation perspective. Finally, we present a case study that evaluates the flat fare policy for route 204 in Suzhou using the proposed method. The results show that the proposed method is feasible.

  5. Pilot survey of subway and bus stop noise levels.

    Science.gov (United States)

    Gershon, Robyn R M; Neitzel, Richard; Barrera, Marissa A; Akram, Muhammad

    2006-09-01

    Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.

  6. Real life testing of a Hybrid PEM Fuel Cell Bus

    Science.gov (United States)

    Folkesson, Anders; Andersson, Christian; Alvfors, Per; Alaküla, Mats; Overgaard, Lars

    Fuel cells produce low quantities of local emissions, if any, and are therefore one of the most promising alternatives to internal combustion engines as the main power source in future vehicles. It is likely that urban buses will be among the first commercial applications for fuel cells in vehicles. This is due to the fact that urban buses are highly visible for the public, they contribute significantly to air pollution in urban areas, they have small limitations in weight and volume and fuelling is handled via a centralised infrastructure. Results and experiences from real life measurements of energy flows in a Scania Hybrid PEM Fuel Cell Concept Bus are presented in this paper. The tests consist of measurements during several standard duty cycles. The efficiency of the fuel cell system and of the complete vehicle are presented and discussed. The net efficiency of the fuel cell system was approximately 40% and the fuel consumption of the concept bus is between 42 and 48% lower compared to a standard Scania bus. Energy recovery by regenerative braking saves up 28% energy. Bus subsystems such as the pneumatic system for door opening, suspension and brakes, the hydraulic power steering, the 24 V grid, the water pump and the cooling fans consume approximately 7% of the energy in the fuel input or 17% of the net power output from the fuel cell system. The bus was built by a number of companies in a project partly financed by the European Commission's Joule programme. The comprehensive testing is partly financed by the Swedish programme "Den Gröna Bilen" (The Green Car). A 50 kW el fuel cell system is the power source and a high voltage battery pack works as an energy buffer and power booster. The fuel, compressed hydrogen, is stored in two high-pressure stainless steel vessels mounted on the roof of the bus. The bus has a series hybrid electric driveline with wheel hub motors with a maximum power of 100 kW. Hybrid Fuel Cell Buses have a big potential, but there are

  7. Modeling and Simulation of Bus Dispatching Policy for Timed Transfers on Signalized Networks

    Science.gov (United States)

    Cho, Hsun-Jung; Lin, Guey-Shii

    2007-12-01

    The major work of this study is to formulate the system cost functions and to integrate the bus dispatching policy with signal control. The integrated model mainly includes the flow dispersion model for links, signal control model for nodes, and dispatching control model for transfer terminals. All such models are inter-related for transfer operations in one-center transit network. The integrated model that combines dispatching policies with flexible signal control modes can be applied to assess the effectiveness of transfer operations. It is found that, if bus arrival information is reliable, an early dispatching decision made at the mean bus arrival times is preferable. The costs for coordinated operations with slack times are relatively low at the optimal common headway when applying adaptive route control. Based on such findings, a threshold function of bus headway for justifying an adaptive signal route control under various time values of auto drivers is developed.

  8. Bus Route Design with a Bayesian Network Analysis of Bus Service Revenues

    OpenAIRE

    Liu, Yi; Jia, Yuanhua; Feng, Xuesong; Wu, Jiang

    2018-01-01

    A Bayesian network is used to estimate revenues of bus services in consideration of the effect of bus travel demands, passenger transport distances, and so on. In this research, the area X in Beijing has been selected as the study area because of its relatively high bus travel demand and, on the contrary, unsatisfactory bus services. It is suggested that the proposed Bayesian network approach is able to rationally predict the probabilities of different revenues of various route services, from...

  9. Assessment and evolution of renewable energy policy: the transition of the Latin-American electricity sectors

    International Nuclear Information System (INIS)

    Bersalli, German

    2017-01-01

    The transition to a more sustainable energy system requires a much faster development of new and renewable energy technologies for electricity generation (RENe). Thus, involving new challenges in the regulation of electricity sector. Additionally, a stronger commitment by emerging and developing countries for a deeper decarbonization trajectory, calls for the strengthening of renewable energy policies. Such policies include designing regulatory instruments that are better adapted for their specific economic and institutional needs. This thesis deals with the evaluation and the redesign of policies that encourage the diffusion of RENe in the context of Latin America's countries. To this end, we first use Environmental Economics theory to analyse the different regulatory instruments available, characterize them and to propose evaluation criteria based on a thorough review of the literature. We then carry out a panel data econometric study, to identify the determining factors of investments in regards to new RENe production capacity; and in particular, to measure the effectiveness of such policies. In a third phase, we mobilize the evolutionary theory of technological change to analyse the process of policy implementation, the existing barriers and the obtained results. This analysis is based on three case studies in the electricity sector of Chile, Brazil and Argentina. And finally, we focus on the challenges related to the massive deployment of RENe in Latin America by 2030-2040: the integration of intermittent energy sources, the access to financing and the industrial challenge. Our research shows that the evolution of the economic and institutional context encourages a dynamic which conditions public policy choices as well as their performance. We therefore propose the basis of an analytical framework for the design and assessment of ambitious long-term promoting policies. These policies must be integrated into a multidimensional and coherent project for the

  10. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2012

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chander, K.; Gikakis, C.

    2012-11-01

    This report is the sixth in an annual series of reports that summarize the progress of fuel cell electric bus (FCEB) development in the United States and discuss the achievements and challenges of introducing fuel cell propulsion in transit. The report also provides a snapshot of current FCEB performance results over the last year. There are 25 active FCEBs in demonstrations this year at eight locations.

  11. Determination of electric dipole transitions in heavy quarkonia using potential non-relativistic QCD

    Science.gov (United States)

    Segovia, Jorge; Steinbeißer, Sebastian

    2018-05-01

    The electric dipole transitions {χ }bJ(1P)\\to γ \\Upsilon (1S) with J = 0, 1, 2 and {h}b(1P)\\to γ {η }b(1S) are computed using the weak-coupling version of a low-energy effective field theory named potential non-relativistic QCD (pNRQCD). In order to improve convergence and thus give firm predictions for the studied reactions, the full static potential is incorporated into the leading order Hamiltonian; moreover, we must handle properly renormalon effects and re-summation of large logarithms. The precision we reach is {k}γ 3/{(mv)}2× O({v}2), where kγ is the photon energy, m is the mass of the heavy quark and v its velocity. Our analysis separates those relativistic contributions that account for the electromagnetic interaction terms in the pNRQCD Lagrangian which are v 2 suppressed and those that account for wave function corrections of relative order v 2. Among the last ones, corrections from 1/m and 1/m2 potentials are computed, but not those coming from higher Fock states since they demand non-perturbative input and are {{{Λ }}}{{QCD}}2/{(mv)}2 or {{{Λ }}}{{QCD}}3/({m}3{v}4) suppressed, at least, in the strict weak coupling regime. These proceedings are based on the forthcoming publication [1].

  12. Optimal control of mode transition for four-wheel-drive hybrid electric vehicle with dry dual-clutch transmission

    Science.gov (United States)

    Zhao, Zhiguo; Lei, Dan; Chen, Jiayi; Li, Hangyu

    2018-05-01

    When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch-transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with H∞ robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance.

  13. Life cycle cost analysis of a car, a city bus and an intercity bus powertrain for year 2005 and 2020

    International Nuclear Information System (INIS)

    Hellgren, Jonas

    2007-01-01

    The international economy, in the beginning of the 20th century, is characterized by uncertainty about the supply and the price of oil. Together with the fast decrease of electrical propulsion component prices, it becomes more and more cost effective to develop vehicles with alternative powertrains. This paper focuses on two questions: Are alternative powertrains especially cost effective for specific applications?; How does an increased fossil fuel price influences the choose of powertrain? To assess these questions, a computer tool named THEPS, developed in a Ph.D. project, is used. Three applications and three scenarios are analysed. The applications, a car, a city bus and an intercity bus, are vehicles all assumed to operate in Sweden. One scenario represents year 2005, the other two year 2020. The two future scenarios are characterized by different fossil fuel prices. The study, presented in the paper, indicates that alternative powertrains can be competitive from a cost perspective, in some applications, already in year 2005. It is for example cost effective to equip a city bus, running in countries with a high fuel price, with a hybrid powertrain. The study also indicates that pure electric, hybrid and/or fuel cell cars will probably be a more cost effective choice than conventional cars in year 2020. Another indication is that it will not be clear which powertrain concept to choose. The reason is that many cost effective powertrain concepts will be offered. The best choice will depend on the application

  14. Electric-Field Control of Oxygen Vacancies and Magnetic Phase Transition in a Cobaltite/Manganite Bilayer

    Science.gov (United States)

    Cui, B.; Song, C.; Li, F.; Zhong, X. Y.; Wang, Z. C.; Werner, P.; Gu, Y. D.; Wu, H. Q.; Saleem, M. S.; Parkin, S. S. P.; Pan, F.

    2017-10-01

    Manipulation of oxygen vacancies (VO ) in single oxide layers by varying the electric field can result in significant modulation of the ground state. However, in many oxide multilayers with strong application potentials, e.g., ferroelectric tunnel junctions and solid-oxide fuel cells, understanding VO behavior in various layers under an applied electric field remains a challenge, owing to complex VO transport between different layers. By sweeping the external voltage, a reversible manipulation of VO and a corresponding fixed magnetic phase transition sequence in cobaltite/manganite (SrCoO3 -x/La0.45Sr0.55MnO3 -y ) heterostructures are reported. The magnetic phase transition sequence confirms that the priority of electric-field-induced VO formation or annihilation in the complex bilayer system is mainly determined by the VO formation energies and Gibbs free-energy differences, which is supported by theoretical analysis. We not only realize a reversible manipulation of the magnetic phase transition in an oxide bilayer but also provide insight into the electric-field control of VO engineering in heterostructures.

  15. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2015

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gikakis, Christina [Federal Transit Administration, Washington, DC (United States)

    2015-12-11

    This report, published annually, summarizes the progress of fuel cell electric bus (FCEB) development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. Various stakeholders, including FCEB developers, transit agencies, and system integrators, have expressed the value of this annual status report, which provides a summary of results from evaluations performed by the National Renewable Energy Laboratory. The annual status report tracks the progress of the FCEB industry toward meeting technical targets, documents the lessons learned, and discusses the path forward for commercial viability of fuel cell technology for transit buses. The 2015 summary results primarily focus on the most recent year for each demonstration, from August 2014 through July 2015. The results for these buses account for more than 1,045,000 miles traveled and 83,000 hours of fuel cell power system operation. The primary results presented in the report are from two demonstrations of fuel-cell-dominant bus designs: the Zero Emission Bay Area Demonstration Group led by Alameda-Contra Costa Transit District (AC Transit) in California and the American Fuel Cell Bus Project at SunLine Transit Agency in California.

  16. Theoretical analysis of the cumulative costs of different diesel bus alternatives for a public transport in the city of Belgrade

    Directory of Open Access Journals (Sweden)

    Jovanović Stevan S.

    2017-01-01

    Full Text Available This paper includes comparative analysis of the environmental, energetic, and financial costs of different bus propulsion, possibly applied on the public transport in the city of Belgrade. It considers the modern diesel bus, the trolleybus, the natural gas bus with the spark ignition engine, the electric bus using LiFePO4 battery, and the electric bus with ultra-capacitor. The results are presented according to the real data and the real electro-energetic situation in Serbia, with the dominantly used lignite coal as primary fuel. This model gives the exact exhaust emission of electric vehicles at the thermal power plant, enables its comparison to the internal combustion engine vehicles. The result in analysis shows that the natural gas bus is the most cost efficient in economical way with overall exploitation price of $87 per 100 km. The trolleybus is more economical then the natural gas powered bus only at high departures rate, higher than 230 per workday.

  17. Road safety issues for bus transport management.

    Science.gov (United States)

    Cafiso, Salvatore; Di Graziano, Alessandro; Pappalardo, Giuseppina

    2013-11-01

    Because of the low percentage of crashes involving buses and the assumption that public transport improves road safety by reducing vehicular traffic, public interest in bus safety is not as great as that in the safety of other types of vehicles. It is possible that less attention is paid to the significance of crashes involving buses because the safety level of bus systems is considered to be adequate. The purpose of this study was to evaluate the knowledge and perceptions of bus managers with respect to safety issues and the potential effectiveness of various technologies in achieving higher safety standards. Bus managers were asked to give their opinions on safety issues related to drivers (training, skills, performance evaluation and behaviour), vehicles (maintenance and advanced devices) and roads (road and traffic safety issues) in response to a research survey. Kendall's algorithm was used to evaluate the level of concordance. The results showed that the majority of the proposed items were considered to have great potential for improving bus safety. The data indicated that in the experience of the participants, passenger unloading and pedestrians crossing near bus stops are the most dangerous actions with respect to vulnerable users. The final results of the investigation showed that start inhibition, automatic door opening, and the materials and internal architecture of buses were considered the items most strongly related to bus passenger safety. Brake assistance and vehicle monitoring systems were also considered to be very effective. With the exception of driver assistance systems for passenger and pedestrian safety, the perceptions of the importance of other driver assistance systems for vehicle monitoring and bus safety were not unanimous among the bus company managers who participated in this survey. The study results showed that the introduction of new technologies is perceived as an important factor in improving bus safety, but a better understanding

  18. Effects of interfacial transition layers on the electrical properties of individual Fe 30 Co 61 Cu 9 /Cu multilayer nanowires

    KAUST Repository

    Ma, Hongbin

    2016-01-01

    In this work, we accurately measure the electrical properties of individual Fe30Co61Cu9/Cu multilayered nanowires using nanomanipulators in in situ scanning electron microscopy to reveal that interfacial transition layers are influential in determining their transport behaviors. We investigate the morphology, crystal structure and chemistry of the Fe30Co61Cu9/Cu multilayered nanowires to characterize them at the nanoscale. We also compare the transport properties of these multilayered nanowires to those of individual pure Cu nanowires and to those of alloy Fe30Co61Cu9 nanowires. The multilayered nanowires with a 50 nm diameter had a remarkable resistivity of approximately 5.41 × 10-7 Ω m and a failure current density of 1.54 × 1011 A m-2. Detailed analysis of the electrical data reveals that interfacial transition layers influence the electrical properties of multilayered nanowires and are likely to have a strong impact on the life of nanodevices. This work contributes to a basic understanding of the electrical parameters of individual magnetic multilayered nanowires for their application as functional building blocks and interconnecting leads in nanodevices and nanoelectronics, and also provides a clear physical picture of a single multilayered nanowire which explains its electrical resistance and its source of giant magnetoresistance. © The Royal Society of Chemistry 2016.

  19. Design & Development of FPGA Based VME Bus Controller

    OpenAIRE

    Himali Patel; Poornima Talwai

    2015-01-01

    The VME bus interface Controller (VIC068A) is used to interface Local CPU bus and VME bus. VME Bus Controller is used in wide application areas where high reliability, good accuracy and high speed are desired to withstand industrial environment like nuclear power plant and process industries. VME Bus controller can configure as Master, Slave, Interrupt Handler, arbiter as well as power monitor. Commercial VME Bus interface controller chips are available from a few vend...

  20. Mastering NServiceBus and persistence

    CERN Document Server

    Helton, Rich

    2014-01-01

    This book is intended for developers, designers, and architects alike who wish to build C# NServiceBus enterprise architectures and learn how ESB persists data and messages to help them attain their goals. No prior knowledge of persistence in NServiceBus is required.

  1. Digital processing data communication systems (bus systems)

    International Nuclear Information System (INIS)

    Fleck, K.

    1980-01-01

    After an introduction to the technology of digital processing data communication systems there are the following chapters: digital communication of processing data in automation technology, the technology of biserial communication, the implementaiton of a bus system, the data transmission of the TDC-2000 system of Honeywell's and the process bus CS 275 in the automation system TELEPERM M of Siemens AG. (WB) [de

  2. Best practices in transit service planning : final report, March 2009.

    Science.gov (United States)

    2009-03-01

    The provision of cost efficient and effective bus transit service is the basic premise upon which transit service is developed and the goal that all public transportations agencies strive to achieve. To attain this goal, public transit agencies must ...

  3. Development and Evaluation of an Economic-Driving Assistance Program for Transit Vehicles

    OpenAIRE

    Baoxin Han; Wanjing Ma; Hanzhou Xie

    2012-01-01

    This paper focuses on development and evaluation of an economic-driving assistance program for transit vehicles (EDTV) which can minimize energy consumption, air pollution emission of buses, and improve the level of service of transit system as well. Taking advantage of the latest advances in information and communication technologies, the EDTV system can provide bus drivers with optimal recommended bus holding times at near-side bus stops and dynamic bus speed to adapt to the real-time traff...

  4. Short-Term Interferential Transabdominal Electrical Stimulation Did Not Change Oral-Rectal Transit Time in Piglets.

    Science.gov (United States)

    Tan, Andre Y F; Sourial, Magdy; Hutson, John M; Southwell, Bridget R

    2018-03-02

    Transcutaneous electrical stimulation (TES) using interferential current (IFC) is a new therapeutic treatment for constipation. Clinical studies show that TES-IFC for 3-6 months improves colonic transit, but it is not clear if short-term stimulation affects transit or the effect requires longer to develop. The aim of this study was to determine if TES-IFC for only four days affects oral-rectal transit time in healthy pigs. Twenty-two 4-5-week old large white female piglets had transit studies during week 4 and week 5 by placing a capsule containing 18 radiopaque plastic markers in the esophagus under anesthetic followed by x-rays at 6, 30, 54, and 78 hours. Animals were randomly assigned to active or control groups. The active group received TES for 30 min daily for four days. Interferential current was applied through four electrodes (4 × 4 cm), with two para-spinal just below the last rib and two on the belly at the same level. Stimulation was at 4000 Hz and 4080-4160 Hz with currents crossing through the abdominal cavity. Whole bowel transit times ranged from 7.7 to 72.2 hours, stomach transit from transit time from 5 to 53 hours. Transit times were the same for the control (median 28.4 hours) and TES-IFC (23.0 hours) groups in the prestimulation and stimulation weeks (control 23.0, TES-IFC 19.8 hours) with no change within or between groups. Four days of half-hour TES-IFC daily in healthy 5-week-old piglets did not change oral-rectal transit time. © 2018 International Neuromodulation Society.

  5. Electric-field driven insulator-metal transition and tunable magnetoresistance in ZnO thin film

    Science.gov (United States)

    Zhang, Le; Chen, Shanshan; Chen, Xiangyang; Ye, Zhizhen; Zhu, Liping

    2018-04-01

    Electrical control of the multistate phase in semiconductors offers the promise of nonvolatile functionality in the future semiconductor spintronics. Here, by applying an external electric field, we have observed a gate-induced insulator-metal transition (MIT) with the temperature dependence of resistivity in ZnO thin films. Due to a high-density carrier accumulation, we have shown the ability to inverse change magnetoresistance in ZnO by ionic liquid gating from 10% to -2.5%. The evolution of photoluminescence under gate voltage was also consistent with the MIT, which is due to the reduction of dislocation. Our in-situ gate-controlled photoluminescence, insulator-metal transition, and the conversion of magnetoresistance open up opportunities in searching for quantum materials and ZnO based photoelectric devices.

  6. Control of Chiral Magnetism Through Electric Fields in Multiferroic Compounds above the Long-Range Multiferroic Transition.

    Science.gov (United States)

    Stein, J; Baum, M; Holbein, S; Finger, T; Cronert, T; Tölzer, C; Fröhlich, T; Biesenkamp, S; Schmalzl, K; Steffens, P; Lee, C H; Braden, M

    2017-10-27

    Polarized neutron scattering experiments reveal that type-II multiferroics allow for controlling the spin chirality by external electric fields even in the absence of long-range multiferroic order. In the two prototype compounds TbMnO_{3} and MnWO_{4}, chiral magnetism associated with soft overdamped electromagnons can be observed above the long-range multiferroic transition temperature T_{MF}, and it is possible to control it through an electric field. While MnWO_{4} exhibits chiral correlations only in a tiny temperature interval above T_{MF}, in TbMnO_{3} chiral magnetism can be observed over several kelvin up to the lock-in transition, which is well separated from T_{MF}.

  7. Single or multiple synchronization transitions in scale-free neuronal networks with electrical or chemical coupling

    International Nuclear Information System (INIS)

    Hao Yinghang; Gong, Yubing; Wang Li; Ma Xiaoguang; Yang Chuanlu

    2011-01-01

    Research highlights: → Single synchronization transition for gap-junctional coupling. → Multiple synchronization transitions for chemical synaptic coupling. → Gap junctions and chemical synapses have different impacts on synchronization transition. → Chemical synapses may play a dominant role in neurons' information processing. - Abstract: In this paper, we have studied time delay- and coupling strength-induced synchronization transitions in scale-free modified Hodgkin-Huxley (MHH) neuron networks with gap-junctions and chemical synaptic coupling. It is shown that the synchronization transitions are much different for these two coupling types. For gap-junctions, the neurons exhibit a single synchronization transition with time delay and coupling strength, while for chemical synapses, there are multiple synchronization transitions with time delay, and the synchronization transition with coupling strength is dependent on the time delay lengths. For short delays we observe a single synchronization transition, whereas for long delays the neurons exhibit multiple synchronization transitions as the coupling strength is varied. These results show that gap junctions and chemical synapses have different impacts on the pattern formation and synchronization transitions of the scale-free MHH neuronal networks, and chemical synapses, compared to gap junctions, may play a dominant and more active function in the firing activity of the networks. These findings would be helpful for further understanding the roles of gap junctions and chemical synapses in the firing dynamics of neuronal networks.

  8. Single or multiple synchronization transitions in scale-free neuronal networks with electrical or chemical coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hao Yinghang [School of Physics, Ludong University, Yantai 264025 (China); Gong, Yubing, E-mail: gongyubing09@hotmail.co [School of Physics, Ludong University, Yantai 264025 (China); Wang Li; Ma Xiaoguang; Yang Chuanlu [School of Physics, Ludong University, Yantai 264025 (China)

    2011-04-15

    Research highlights: Single synchronization transition for gap-junctional coupling. Multiple synchronization transitions for chemical synaptic coupling. Gap junctions and chemical synapses have different impacts on synchronization transition. Chemical synapses may play a dominant role in neurons' information processing. - Abstract: In this paper, we have studied time delay- and coupling strength-induced synchronization transitions in scale-free modified Hodgkin-Huxley (MHH) neuron networks with gap-junctions and chemical synaptic coupling. It is shown that the synchronization transitions are much different for these two coupling types. For gap-junctions, the neurons exhibit a single synchronization transition with time delay and coupling strength, while for chemical synapses, there are multiple synchronization transitions with time delay, and the synchronization transition with coupling strength is dependent on the time delay lengths. For short delays we observe a single synchronization transition, whereas for long delays the neurons exhibit multiple synchronization transitions as the coupling strength is varied. These results show that gap junctions and chemical synapses have different impacts on the pattern formation and synchronization transitions of the scale-free MHH neuronal networks, and chemical synapses, compared to gap junctions, may play a dominant and more active function in the firing activity of the networks. These findings would be helpful for further understanding the roles of gap junctions and chemical synapses in the firing dynamics of neuronal networks.

  9. Optimal Design of the Feeder-Bus Network Based on the Transfer System

    Directory of Open Access Journals (Sweden)

    Lianbo Deng

    2013-01-01

    Full Text Available This paper studied the classic feeder-bus network design problem (FBNDP, which can be described as follows: for the passenger travel demand between rail stations and bus stops on a given urban transit network, it designs the optimal feeder bus routes and frequencies so as to minimize the passengers’ travel expense and the operator’s cost. We extended the demand pattern of M-to-1 in most existing researches to M-to-M. We comprehensively considered the passenger travel cost, which includes the waiting and riding cost on the bus, riding cost on rail, and transfer cost between these two transportation modes, and presented a new genetic algorithm that determines the optimal feeder-bus operating frequencies under strict constraint conditions. The numerical examples under different demand patterns have been experienced and analysed, which showed the robustness and efficiency of the presented algorithm. We also found that the distribution pattern of the travel demand has a significant influence on the feeder-bus network construction.

  10. Modelling modal shift due to the enhanced level of bus service

    Directory of Open Access Journals (Sweden)

    P. Vedagiri

    2009-06-01

    Full Text Available This study is concerned with the estimation of the probable shift of auto-rickshaw (three wheeled motorized para-transit vehicle users to the bus due to an increase in its level of service after providing exclusive bus lanes on Indian city roads carrying heterogeneous traffic. The quantum of an increase in the level of bus service due to the introduction of an exclusive bus lane was determined using a recently developed simulation model of heterogeneous traffic flow. The data on other factors (variables that might cause modal shift from the auto-rickshaw to the bus was collected conducting a home-interview survey based on the stated preference approach. A binary logit model of mode-choice was then calibrated using the collected data and the model was also validated using a holdout sample. A mode-choice probability curve to depict the possible shift of auto-rickshaw users to the bus is developed taking difference in the travel times of two-modes as the basis to serve as a user friendly tool to analyze the possible modal shift for a wide range of the values of the involved variables.

  11. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  12. Integration of refrigerators into facility automation with the aid of bus systems; Integration der Kaeltetechnik in die Gebaeudeautomation mit Bus-Systemen

    Energy Technology Data Exchange (ETDEWEB)

    Baumgarth, S.; Heiser, M. [Fachhochschule Braunschweig-Wolfenbuettel, Wolfenbuettel (DE). Inst. fuer Verbrennungstechnik und Prozessautomation (IVP)

    2000-07-01

    The integration of refrigeration systems in building automation is illustrated by the example of a ventilation system and a cooling ceiling. Cold is supplied by a coldwater unit. This necessitates supply of consumption data to the central refrigeration system. So far, technical facilities are commonly controlled by DDC systems and in-house bus systems. The demand for open communication between different systems resulted in the development of neutral systems like FND and Profibus, which were followed by a multitude of other, less generally accepted systems. In the field of electrical installations, the European Installation Bus EIB was generally accepted as a certified, open bus system which can be combined with DDC technology and integrated in in-house control systems. Another technology developed in the USA is the Local Operating Network, LON, whic has a hither transmission rate and higher information content for the various bus members. The contribution compares the two bus systems. [German] Die Einbindung der Kaeltetechnik in die Gebaeudeautomation wird an den Beispielen Lueftungsanlage und Kuehldecke vorgestellt. Die erforderliche Kaelte soll durch einen Kaltwasserersatz energieoptimiert bereitgestellt werden. Dazu muessen Informationen aus dem Verbraucherbereich in der Kaeltezentrale zur Verfuegung stehen. RTL-Anlagen wurden bisher mittels DDC-Technik und firmenspezifischen Bus-Systemen geregelt und gesteuert. Wenn verschiedene Anlagen durch DDC-Systeme unterschiedlicher Hersteller betrieben wurden, so war anfaenglich eine gemeinsame Ueberwachung auf einer zentralen Leitwarte nur ueber Gateways moeglich. Aus der Forderung nach offener Kommunikation unterschiedlicher Systeme entstanden die ersten firmenneutralen Entwicklungen FND und Profibus. Es folgten eine Vielzahl weiterer Netz- und Busdefinitionen und deren Kommunikationsprotokolle, denen jedoch weitgehend eine allgemeine Anerkennung versagt blieb. Im Bereich der Elektroinstallation profilierte sich der

  13. Matrix elements of the electric multiple transition and relativistic correction operators in the case of complex configurations

    International Nuclear Information System (INIS)

    Kanyauskas, Yu.M.; Rudzikas, Z.B.

    1976-01-01

    Operators and their submatrix elements are studied in the framework of the electric multipole transitions of complex atoms with account of relativistic corrections of the order of the square of the fine structure constant. The analysis is performed by means of irreducible tensor operators and genealogical coefficients. It has been assumed that angular momenta of individual shells are coupled with each other according to ls, lk, jk and jj coupling. Formulas are given for the operator which causes the relativistic corrections for the single-electron multipole transition and for its submatrix element in the case of configurations with two unfilled shells. A possibility is discussed of using the formulas suggested for calculation. As follows from analysis, the relativistic correction operators even with the pure ls coupling allow intercombination transitions with ΔS equals +-1. The expressions obtained may turn out to be useful for performing calculations in the case of the intermediate type of coupling

  14. Thermal conductivity, electric resistivity, and Lorenz function for some transition metals measured by a direct electric heating technique

    International Nuclear Information System (INIS)

    Binkele, Ludolf

    1985-01-01

    The validity of the Wiedemann-Franz-Lorenz law in its standard form is disputed in the case of transition metals. However, normal behaviour could be demonstrated for the transition metals molybdenum, tantalum, and niobium by the application of an already tried and tested, and recently improved, modified Kohlrausch measuring method; that is, the high-temperature Lorenz number of these metals takes the Sommerfeld value, within measuring uncertainties of approx. 3%. In the case of tungsten, saturation was observed 16.7% above the Sommerfeld value. Even the Lorenz number of platinum seems to take on a saturation value at that level at temperatures above 1400 K. The lattice conductivity separated by various processes displays a temperature dependence describable by an exponential law for all the metals studied, in contrast to previous assumptions. (author)

  15. Voltage- and current-activated metal–insulator transition in VO2-based electrical switches: a lifetime operation analysis

    Directory of Open Access Journals (Sweden)

    Aurelian Crunteanu, Julien Givernaud, Jonathan Leroy, David Mardivirin, Corinne Champeaux, Jean-Christophe Orlianges, Alain Catherinot and Pierre Blondy

    2010-01-01

    Full Text Available Vanadium dioxide is an intensively studied material that undergoes a temperature-induced metal–insulator phase transition accompanied by a large change in electrical resistivity. Electrical switches based on this material show promising properties in terms of speed and broadband operation. The exploration of the failure behavior and reliability of such devices is very important in view of their integration in practical electronic circuits. We performed systematic lifetime investigations of two-terminal switches based on the electrical activation of the metal–insulator transition in VO2 thin films. The devices were integrated in coplanar microwave waveguides (CPWs in series configuration. We detected the evolution of a 10 GHz microwave signal transmitted through the CPW, modulated by the activation of the VO2 switches in both voltage- and current-controlled modes. We demonstrated enhanced lifetime operation of current-controlled VO2-based switching (more than 260 million cycles without failure compared with the voltage-activated mode (breakdown at around 16 million activation cycles. The evolution of the electrical self-oscillations of a VO2-based switch induced in the current-operated mode is a subtle indicator of the material properties modification and can be used to monitor its behavior under various external stresses in sensor applications.

  16. Online transition matrix identification of the state evolution model for the extended Kalman filter in electrical impedance tomography

    International Nuclear Information System (INIS)

    Moura, Fernando S; Aya, Julio C C; Lima, Raul G; Fleury, Agenor T

    2008-01-01

    One of the electrical impedance tomography objectives is to estimate the electrical resistivity distribution in a domain based only on contour electrical potential measurements caused by an imposed electrical current distribution into the boundary. In biomedical applications, the random walk model is frequently used as evolution model and, under this conditions, it is observed poor tracking ability of the Extended Kalman Filter (EKF). An analytically developed evolution model is not feasible at this moment. The present work investigates the possibility of identifying the evolution model in parallel to the EKF and updating the evolution model with certain periodicity. The evolution model is identified using the history of resistivity distribution obtained by a sensitivity matrix based algorithm. To numerically identify the linear evolution model, it is used the Ibrahim Time Domain Method, normally used to identify the transition matrix on structural dynamics. The investigation was performed by numerical simulations of a time varying domain with the addition of noise. Numerical dificulties to compute the transition matrix were solved using a Tikhonov regularization. The EKF numerical simulations suggest that the tracking ability is significantly improved.

  17. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2017

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew B [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-11-21

    This report, published annually, summarizes the progress of fuel cell electric bus (FCEB) development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of results from evaluations performed by the National Renewable Energy Laboratory. This annual status report combines results from all FCEB demonstrations, tracks the progress of the FCEB industry toward meeting technical targets, documents the lessons learned, and discusses the path forward for commercial viability of fuel cell technology for transit buses. These data and analyses help provide needed information to guide future early-stage research and development. The 2017 summary results primarily focus on the most recent year for each demonstration, from August 2016 through July 2017. The primary results presented in the report are from five demonstrations of two different fuel-cell-dominant bus designs: Zero Emission Bay Area Demonstration Group led by Alameda-Contra Costa Transit District (AC Transit) in California; American Fuel Cell Bus (AFCB) Project at SunLine Transit Agency in California; AFCB Project at the University of California at Irvine; AFCB Project at Orange County Transportation Authority; and AFCB Project at Massachusetts Bay Transportation Authority.

  18. The high current bus-bars of the LHC from conception to manufacture

    CERN Document Server

    Belova, L; Perinet-Marquet, J-L; Urpin, C

    2006-01-01

    The main magnets of the LHC are series-connected electrically in different excitation circuits by means of superconducting bus-bars, carrying a maximum current of 13 kA. These superconducting bus-bars consist of a superconducting cable thermally and electrically coupled to a copper section all along length. The function of the copper section is essentially to provide an alternative path for the magnet current in case the superconducting cable loses its superconductivity and returns to normal state because of a transient system disturbance or normal zone propagation coming from the neighboring magnets. When a superconducting bus-bar quenches to normal state its temperature must always stay below a safe values of about 100 ° C while the copper is conducting. With regard to that, a quench signal is initiated, which in turn triggers the ramping down of the current from 13000 A to 0....

  19. A Smooth Transition Logit Model of the Effects of Deregulation in the Electricity Market

    DEFF Research Database (Denmark)

    Hurn, A.S.; Silvennoinen, Annastiina; Teräsvirta, Timo

    We consider a nonlinear vector model called the logistic vector smooth transition autoregressive model. The bivariate single-transition vector smooth transition regression model of Camacho (2004) is generalised to a multivariate and multitransition one. A modelling strategy consisting of specific......We consider a nonlinear vector model called the logistic vector smooth transition autoregressive model. The bivariate single-transition vector smooth transition regression model of Camacho (2004) is generalised to a multivariate and multitransition one. A modelling strategy consisting...... of specification, including testing linearity, estimation and evaluation of these models is constructed. Nonlinear least squares estimation of the parameters of the model is discussed. Evaluation by misspecification tests is carried out using tests derived in a companion paper. The use of the modelling strategy...

  20. Building system technology with installation bus. Planning now for the future; Gebaeudesystemtechnik - mit Installationsbus. Heute schon an morgen denken

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, D. [RWE Energie AG, Essen (Germany)

    1995-12-31

    In chapter 16 of the anthology about building technology the building system technology with installation bus is described. The following aspects are discussed: limits of the conventional electric installation, building system technology, building system technology - illusion or reality?; The European Installation Bus Association (EIBA). (BWI) [Deutsch] Kapitel 16 des Sammelbandes ueber Building Control ist dem Thema der Gebaeudesystemtechnik mit Installationsbus gewidmet. In diesem Zusammenhang werden folgende Themenbereiche angesprochen: Grenzen der konventionellen Elektroinstallation; Gebaeudesystemtechnik; Gebaeudesystemtechnik - Illusion oder Realitaet?; Die EIBA (European Installation Bus Association). (BWI)

  1. A Rule-Based Energy Management Strategy for a Plug-in Hybrid School Bus Based on a Controller Area Network Bus

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-06-01

    Full Text Available This paper presents a rule-based energy management strategy for a plug-in hybrid school bus (PHSB. In order to verify the effectiveness and rationality of the proposed energy management strategy, the powertrain and control models were built with MATLAB/Simulink. The PHSB powertrain model includes an engine model, ISG (integrated started and generator model, drive motor model, power battery packs model, driver model, and vehicle longitudinal dynamics model. To evaluate the controller area network (CAN bus performance features such as the bus load, signal hysteresis, and to verify the reliability and real-time performance of the CAN bus multi-node control method, a co-simulation platform was built with CANoe and MATLAB/Simulink. The co-simulation results show that the control strategy can meet the requirements of the PHSB’s dynamic performance. Meanwhile, the charge-depleting mode (CD and charge-sustaining mode (CS can switch between each other and maintain a state-of-charge (SoC of around 30%, indicating that the energy management strategy effectively extends the working period of the CD mode and improves the fuel economy further. The energy consumption per 100 km includes 13.7 L diesel and 10.5 kW·h electricity with an initial SoC of 75%. The CANoe simulation results show that the bus communication performs well without error frames.

  2. Structure of ground status in magic nuclei and description of their electric transition probabilities

    International Nuclear Information System (INIS)

    Savane, Y.Sy.

    1996-11-01

    The structure of the low-lying states in the even-even semi-magic nuclei ( 106-114 50 Sn) and the reduced transition probabilities B(E2, 6 + 1 → 4 = 1 ) for E2-transition have been investigated in the frame of the quasiparticle-phonon nuclear model. The model wave function includes a quasiparticle + two phonons components. It is shown that the small values of the transitions are connected with the non collective structure of the states. The calculated values are in agreement with the observed property of decreasing of the transition with increasing of mass number. (author). 16 refs, 6 tabs

  3. A preliminary survey analysis of school shuttle bus system towards smart mobility solutions

    Science.gov (United States)

    Yue, Wong Seng; Hoy, Cheong Wan; Chye, Koh Keng

    2017-10-01

    Mobility and accessibility are crucial indicators of urban development. Public transport in the urban areas came into existence to fulfil transportation needs as well as mobility and accessibility demands. Ridership can be affected by the quality and quantity of transit service. However, technical improvements are needed for such as real-time bus information, controlling run time and headway delay. Thus, this paper is aimed to carry out a preliminary survey to determine the problems of school shuttle bus that faced by the students in a selected educational institution, their perceptions of using shuttle bus tracking and information mobile application and impacts of real-time information of public transits on bus ridership and towards smart mobility solutions. Efficient public transportation system needs further investigation about the role of mobile application for the bus tracking system in supporting smart mobility actions and real-time information. The proposed application also provides a smart solution for the management of public infrastructures and urban facilities in Malaysia in future. Eventually, this study opens an opportunity to improve Malaysian quality of life on the public value that created for the city as a whole.

  4. A summary of design, policies and operational characteristics for shared bicycle/bus lanes.

    Science.gov (United States)

    2012-07-01

    This report contains the results of an investigation of the design and operation of shared bicycle/bus lanes in municipalities in the United States and other countries. These lanes are designated for use by public transit buses, bicycles, and usually...

  5. The end of regulated electricity sales prices: thinking transition in a strategic way

    International Nuclear Information System (INIS)

    Hernandez, Pablo; O'Sullivan, Brian

    2014-01-01

    In this article, the authors state that the end of regulated tariffs is inevitable, and present the guidelines of the transition mode. Then, they highlight that this transition must be designed in a strategic way by preparing the negotiation, by pooling providers and enterprises, by valorising flexibilities of the industrial or tertiary asset, and by putting energy efficiency forward

  6. Observation of electric quadrupole transitions to Rydberg nd states of ultracold rubidium atoms

    NARCIS (Netherlands)

    Tong, D.; Farooqi, S.M.; Kempen, van E.G.M.; Pavlovic, Z.; Stanojevic, J.; Coté, R.; Eyler, E.E.; Gould, P.L.

    2009-01-01

    We report the observation of dipole-forbidden, but quadrupole-allowed, one-photon transitions to high-Rydberg states in Rb. Using pulsed uv excitation of ultracold atoms in a magneto-optical trap, we excite 5s¿nd transitions over a range of principal quantum numbers n=27–59. Compared to

  7. Bus Route Design with a Bayesian Network Analysis of Bus Service Revenues

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2018-01-01

    Full Text Available A Bayesian network is used to estimate revenues of bus services in consideration of the effect of bus travel demands, passenger transport distances, and so on. In this research, the area X in Beijing has been selected as the study area because of its relatively high bus travel demand and, on the contrary, unsatisfactory bus services. It is suggested that the proposed Bayesian network approach is able to rationally predict the probabilities of different revenues of various route services, from the perspectives of both satisfying passenger demand and decreasing bus operation cost. This way, the existing bus routes in the studied area can be optimized for their most probable high revenues.

  8. Bus and Tag Terminators for IBM system/360

    CERN Multimedia

    Control units were connected to the channels with "Bus and Tag" cable pairs. The bus cables carried the address and data information and the tag cables identified what data was on the bus. There were three general types of bus-and-tag cables produced by IBM.

  9. PCISIM - A Simulation Tool for PCI Bus Based Systems

    DEFF Research Database (Denmark)

    Sharp, Robin

    1999-01-01

    This document describes a PCI bus simulator for use in evaluating the feasibility of system designs based on this bus.......This document describes a PCI bus simulator for use in evaluating the feasibility of system designs based on this bus....

  10. Influence of the Dirac-Hartree-Fock starting potential on the parity-nonconserving electric-dipole-transition amplitudes in cesium and thallium

    Science.gov (United States)

    Perger, W. F.; Das, B. P.

    1987-01-01

    The parity-nonconserving electric-dipole-transition amplitudes for the 6s1/2-7s1/2 transition in cesium and the 6p1/2-7p1/2 transition in thallium have been calculated by the Dirac-Hartree-Fock method. The effects of using different Dirac-Hartree-Fock atomic core potentials are examined and the transition amplitudes for both the length and velocity gauges are given. It is found that the parity-nonconserving transition amplitudes exhibit a greater dependence on the starting potential for thallium than for cesium.

  11. Holographic Van der Waals phase transition of the higher-dimensional electrically charged hairy black hole

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui-Ling [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Shenyang Normal University, College of Physics Science and Technology, Shenyang (China); Feng, Zhong-Wen [China West Normal University, College of Physics and Space Science, Nanchong (China); Zu, Xiao-Tao [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China)

    2018-01-15

    With motivation by holography, employing black hole entropy, two-point connection function and entanglement entropy, we show that, for the higher-dimensional Anti-de Sitter charged hairy black hole in the fixed charged ensemble, a Van der Waals-like phase transition can be observed. Furthermore, based on the Maxwell equal-area construction, we check numerically the equal-area law for a first order phase transition in order to further characterize the Van der Waals-like phase transition. (orig.)

  12. Holographic Van der Waals phase transition of the higher-dimensional electrically charged hairy black hole

    International Nuclear Information System (INIS)

    Li, Hui-Ling; Feng, Zhong-Wen; Zu, Xiao-Tao

    2018-01-01

    With motivation by holography, employing black hole entropy, two-point connection function and entanglement entropy, we show that, for the higher-dimensional Anti-de Sitter charged hairy black hole in the fixed charged ensemble, a Van der Waals-like phase transition can be observed. Furthermore, based on the Maxwell equal-area construction, we check numerically the equal-area law for a first order phase transition in order to further characterize the Van der Waals-like phase transition. (orig.)

  13. Large truck and bus crash facts, 2010.

    Science.gov (United States)

    2012-09-01

    This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2010. Selected crash statistics on passenger : vehicles are also presen...

  14. Large truck and bus crash facts, 2012.

    Science.gov (United States)

    2014-06-01

    This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and property damage only crashes involving large trucks and buses in 2012. Selected crash statistics on passenger vehicles are also presented ...

  15. Large truck and bus crash facts, 2013.

    Science.gov (United States)

    2015-04-01

    This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and property damage only crashes involving large trucks and buses in 2013. Selected crash statistics on passenger vehicles are also presented ...

  16. Large truck and bus crash facts, 2009.

    Science.gov (United States)

    2011-10-01

    This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2009. Selected crash statistics on passenger : vehicles are also presen...

  17. Large truck and bus crash facts, 2011.

    Science.gov (United States)

    2013-10-01

    This annual edition of Large Truck and Bus Crash Facts contains descriptive statistics about fatal, injury, and : property damage only crashes involving large trucks and buses in 2011. Selected crash statistics on passenger : vehicles are also presen...

  18. Passenger bus industry weather information application.

    Science.gov (United States)

    2011-03-21

    Adverse weather significantly affects the United States national transportation system, including commercial companies : that rely on highways to support their enterprises. The Passenger Bus (Motorcoach) Industry (PBI) is one such affected : user who...

  19. Bicycle-bus conflict area study.

    Science.gov (United States)

    2009-11-01

    Increasing bicycle use and bus ridership are both desirable policy goals : from a sustainability standpoint, but on city streets these two modes of : transport are often in conflict. While occupying opposite ends of the size : and weight spectrum, th...

  20. TMS communications software. Volume 2: Bus interface unit

    Science.gov (United States)

    Gregor, P. J.

    1979-01-01

    A data bus communication system to support the space shuttle's Trend Monitoring System (TMS) and to provide a basis for evaluation of the bus concept is described. Installation of the system included developing both hardware and software interfaces between the bus and the specific TMS computers and terminals. The software written for the microprocessor-based bus interface units is described. The software implements both the general bus communications protocol and also the specific interface protocols for the TMS computers and terminals.

  1. Comparison and status of 32 bit backplane bus architectures

    International Nuclear Information System (INIS)

    Muller, K.D.

    1985-01-01

    With the introduction of 32 bit microprocessors several new 32 bit backplane bus architectures have been developed and are in the process for standardization. Among these are Future Bus (IEEE P896.1), VME-Bus (IEEE 1014), MULTIBUS II, Nu-Bus and Fastbus (IEEE 960). The paper describes and compares the main features of these bus architectures and mentions the status of national and international standardization efforts

  2. The seated bus passenger--a review.

    Science.gov (United States)

    Levis, J A

    1978-09-01

    The paper describes the inter-relationship of anthropometry, rig studies and dynamic testing of aspects related to problems of the seated bus passenger. It seeks to draw together sub-sections of a very large study sponsored by the government through the Transport and Road Research Laboratory and undertaken by the Human Factors Group of Leyland Truck and Bus. It is relevant to all those designing passenger carrying transport systems.

  3. The Gozo discovery bus : a successful experiment

    OpenAIRE

    Vella, Maryrose

    2008-01-01

    The introduction of a tourist discovery bus in Gozo came about as a result of an EU Project which is part of the Interreg III B Archimed programmes in which the Islands and Small States Institute of the University of Malta participated. Other countries participating in this programme besides Malta, represented by the Islands and Small States Institute, are Italy, Cyprus and Greece. The discovery bus service was aimed at encouraging more tourists to come to Gozo and enabling them to visit stra...

  4. NOC AND BUS ARCHITECTURE: A COMPARISON

    OpenAIRE

    RAJEEV KAMAL; NEERAJ YADAV

    2012-01-01

    Network-on-chip designs promise to offer considerable advantages over the traditional bus-based architecture. As continuing scaling of Moore’s law enables ever greater transistor densities, design complexity, power limitations and application convergence networks have started to replace busses in much smaller systems and the enhancement of NoC. This paper summarizes the advantages of the NoC and the limitations of traditional bus based architecture. In this paper we discuss a detailed compari...

  5. Bus line classification using neural networks

    OpenAIRE

    Jiménez Alonso, Felipe; Serradilla García, Francisco; Román de Andrés, Alfonso; Naranjo Hernandez, Jose Eugenio

    2014-01-01

    Grouping urban bus routes is necessary when there are evidences of significant differences among them. In Jiménez et al. (2013), a reduced sample of routes was grouped into clusters utilizing kinematic measured data. As a further step, in this paper, the remaining urban bus routes of a city, for which no kinematic measurements are available, are classified. For such purpose we use macroscopic geographical and functional variables to describe each route, while the clustering process is perform...

  6. Analysis on the phase transition behavior of Cu base bulk metallic glass by electrical resistivity measurement

    International Nuclear Information System (INIS)

    Ji, Young Su; Chung, Sung Jae; Ok, Myoung-Ryul; Hong, Kyung Tae; Suh, Jin-Yoo; Byeon, Jai Won; Yoon, Jin-Kook; Lee, Kyung Hwan; Lee, Kyung Sub

    2007-01-01

    The crystallization behavior of Cu 43 Zr 43 Al 7 Ag 7 (numbers indicate at.%) bulk metallic glass was investigated using the isothermal electrical resistivity measurements at 450 deg. C in the supercooled liquid region. The crystallization process is a single step phase transformation. To analyze the electrical resistivity reduction, microstructure evolutions were analyzed using differential scanning calorimetry, X-ray diffraction, transmission electron microscopy and small-angle X-ray scattering. The Avrami parameter of the electrical resistivity reduction step was 1.73, indicating that the crystallization process is a diffusion-controlled growth of intermetallic compounds with decreasing nucleation rate

  7. Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment

    OpenAIRE

    Ngo, Nicole S.

    2015-01-01

    Abstract Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards...

  8. Common bus multinode sensor system

    International Nuclear Information System (INIS)

    Kelly, T.F.; Naviasky, E.H.; Evans, W.P.; Jefferies, D.W.; Smith, J.R.

    1988-01-01

    This patent describes a nuclear power plant including a common bus multinode sensor system for sensors in the nuclear power plant, each sensor producing a sensor signal. The system consists of: a power supply providing power; a communication cable coupled to the power supply; plural remote sensor units coupled between the cable and one or more sensors, and comprising: a direct current power supply, connected to the cable and converting the power on the cable into direct current; an analog-to-digital converter connected to the direct current power supply; an oscillator reference; a filter; and an integrated circuit sensor interface connected to the direct current power supply, the analog-to-digital converter, the oscillator crystal and the filter, the interface comprising: a counter receiving a frequency designation word from external to the interface; a phase-frequency comparator connected to the counter; an oscillator connected to the oscillator reference; a timing counter connected to the oscillator, the phase/frequency comparator and the analog-to-digital converter; an analog multiplexer connectable to the sensors and the analog-to-digital converter, and connected to the timing counter; a shift register operatively connected to the timing counter and the analog-to-digital converter; an encoder connected to the shift register and connectable to the filter; and a voltage controlled oscillator connected to the filter and the cable

  9. Crashworthiness evaluation of mass transit buses.

    Science.gov (United States)

    2008-11-01

    Mass transit bus systems are an integral part of the national transportation network, serving more than 20.6 billion passenger-miles per year with a relatively low fatality rate. Bus occupant injuries are evenly distributed among crashes on all sides...

  10. Electric-field-induced modification of the magnon energy, exchange interaction, and curie temperature of transition-metal thin films.

    Science.gov (United States)

    Oba, M; Nakamura, K; Akiyama, T; Ito, T; Weinert, M; Freeman, A J

    2015-03-13

    The electric-field-induced modification in the Curie temperature of prototypical transition-metal thin films with the perpendicular magnetic easy axis, a freestanding Fe(001) monolayer and a Co monolayer on Pt(111), is investigated by first-principles calculations of spin-spiral structures in an external electric field (E field). An applied E field is found to modify the magnon (spin-spiral formation) energy; the change arises from the E-field-induced screening charge density in the spin-spiral states due to p-d hybridizations. The Heisenberg exchange parameters obtained from the magnon energy suggest an E-field-induced modification of the Curie temperature, which is demonstrated via Monte Carlo simulations that take the magnetocrystalline anisotropy into account.

  11. Electric controlling of surface metal-insulator transition in the doped BaTiO3 film

    Directory of Open Access Journals (Sweden)

    Wei Xun

    2017-07-01

    Full Text Available Based on first-principles calculations, the BaTiO3(BTO film with local La-doping is studied. For a selected concentration and position of doping, the surface metal-insulator transition occurs under the applied electric field, and the domain appears near the surface for both bipolar states. Furthermore, for the insulated surface state, i.e., the downward polarization state in the doped film, the gradient bandgap structure is achieved, which favors the absorption of solar energy. Our investigation can provide an alternative avenue in modification of surface property and surface screening effect in polar materials.

  12. Electric-Field-Driven Dual Vacancies Evolution in Ultrathin Nanosheets Realizing Reversible Semiconductor to Half-Metal Transition.

    Science.gov (United States)

    Lyu, Mengjie; Liu, Youwen; Zhi, Yuduo; Xiao, Chong; Gu, Bingchuan; Hua, Xuemin; Fan, Shaojuan; Lin, Yue; Bai, Wei; Tong, Wei; Zou, Youming; Pan, Bicai; Ye, Bangjiao; Xie, Yi

    2015-12-02

    Fabricating a flexible room-temperature ferromagnetic resistive-switching random access memory (RRAM) device is of fundamental importance to integrate nonvolatile memory and spintronics both in theory and practice for modern information technology and has the potential to bring about revolutionary new foldable information-storage devices. Here, we show that a relatively low operating voltage (+1.4 V/-1.5 V, the corresponding electric field is around 20,000 V/cm) drives the dual vacancies evolution in ultrathin SnO2 nanosheets at room temperature, which causes the reversible transition between semiconductor and half-metal, accompanyied by an abrupt conductivity change up to 10(3) times, exhibiting room-temperature ferromagnetism in two resistance states. Positron annihilation spectroscopy and electron spin resonance results show that the Sn/O dual vacancies in the ultrathin SnO2 nanosheets evolve to isolated Sn vacancy under electric field, accounting for the switching behavior of SnO2 ultrathin nanosheets; on the other hand, the different defect types correspond to different conduction natures, realizing the transition between semiconductor and half-metal. Our result represents a crucial step to create new a information-storage device realizing the reversible transition between semiconductor and half-metal with flexibility and room-temperature ferromagnetism at low energy consumption. The as-obtained half-metal in the low-resistance state broadens the application of the device in spintronics and the semiconductor to half-metal transition on the basis of defects evolution and also opens up a new avenue for exploring random access memory mechanisms and finding new half-metals for spintronics.

  13. Effect of metallic and hyperbolic metamaterial surfaces on electric and magnetic dipole emission transitions

    DEFF Research Database (Denmark)

    Ni, X.; Naik, G. V.; Kildishev, A. V.

    2011-01-01

    Spontaneous emission patterns of electric and magnetic dipoles on different metallic surfaces and a hyperbolic metamaterial (HMM) surface were simulated using the dyadic Green’s function technique. The theoretical approach was verified by experimental results obtained by measuring angular......-dependent emission spectra of europium ions on top of different films. The results show the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces. The results of numerical calculations agree well with experimental data....

  14. Observation of interference between stark and electric quadrupole transitions in LIF from He atoms in plasmas

    International Nuclear Information System (INIS)

    Takiyama, K.; Namba, S.; Furukawa, S.; Oda, T.; James, B.W.; Andruczyk, D.

    2004-01-01

    Interference between Stark-induced dipole and electric quadrupole amplitudes was observed in a He hollow cathode plasma with axial magnetic field perpendicular to the sheath electric field E by laser-induced fluorescence (LIF) method. Circularly polarized LIF signals were observed in the sheath region. Spatial profile of the degree of polarization P c showed characteristic features of the interference. Using theoretically calculated P c -E relationship, E-profile was successfully obtained form the measure P c . (author)

  15. On the road to fossil-free public transport: The case of Swedish bus fleets

    International Nuclear Information System (INIS)

    Xylia, Maria; Silveira, Semida

    2017-01-01

    Public transport is important for Sweden to acquire a fossil-fuel independent vehicle fleet by 2030. The aim of this paper is to assess the status of Swedish public bus fleets towards decarbonization, and explore factors affecting regional performance variations and fuel choices. Environmental performance indicators such as renewable fuel shares, CO 2 emissions, and energy efficiency are analyzed nationally and regionally. Fuel preferences and best practices are investigated through a survey and interviews with experts working with strategic planning at Public Transport Authorities. Almost 60% of the bus transport volume ran on renewables in 2014 compared to 8% in 2007, but regional variations are significant, partly due to factors such as driving conditions, bus and fuel types, typical trip lengths, and climatic conditions. However, there is no strong correlation between population densities or bus transport volume and the share of renewables achieved. This places political will, strategic planning and policies to promote public transport as key factors affecting renewable fuel deployment. Environmental factors are a priority when choosing fuels, while barriers to renewable fuels are mainly economic and political. Meanwhile, despite the overall progress, achievements in energy efficiency improvement are falling short in comparison to emissions reduction and adoption of renewable fuels, thus requiring further attention. - Highlights: • The penetration of renewables in Swedish public bus fleets reached ca. 60% in 2014. • Public bus emissions per vehicle-km have decreased by 43% between 2007 and 2014. • Efforts are needed to improve energy efficiency in bus transport. • Electricity is likely to receive increased attention according to expert survey.

  16. Prediction of the oscillator strengths for the electric dipole transitions in Th II

    Energy Technology Data Exchange (ETDEWEB)

    Dembczynski, Jerzy [Institute of Control and Information Engineering, Faculty of Electrical Engineering, Poznan University of Technology, Piotrowo 3A, 60-965 Poznan (Poland); Ruczkowski, Jaroslaw; Elantkowska, Magdalena [Laboratory of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13B, 60-965 Poznan (Poland)

    2014-07-01

    In order to parametrize the oscillator strength, the matrix of angular coefficients of the possible transitions in multiconfiguration system were calculated. In the odd and even configuration systems, the fine structure eigenvectors for both parities were obtained, using our semiempirical method, which taken into account also the second order effects, resulting from the excitations from electronic closed shells to open shells and from open shells to empty shell. The correctness of the fine structure wave functions was verified by the comparison of calculated and experimental hyperfine structure constants for Th II available in the literature. The least square fit to experimental values for some transitions allow to obtain the values of radial parameters and predict the oscillator strengths values for all possible transitions from the levels under consideration. These calculations are necessary for the design of the nuclear frequency standard based on the thorium ion.

  17. Conceptual design and development of a superconducting bus-line for the Large Helical Device

    International Nuclear Information System (INIS)

    Mito, T.; Takahata, K.; Yamada, S.; Yamamoto, J.; Uede, T.; Ikeda, M.

    1993-01-01

    A superconducting bus-line is proposed and preliminarily tested as an electrical feeder between the superconducting coils of the Large Helical Device (LHD) and their electrical power supply. The bus-line consists of a superconductor and its cryogenic transfer-line. The superconductor is a specially developed aluminum stabilized NbTi wire, which is installed in the innermost channel of the transfer-line. The vacuum insulated transfer-line consists of four corrugated tubes assembled coaxially. Liquid helium flows through the innermost channel and shield gas flows through another annular channel in the line. We are completing the conceptual design of the bus-line and the installation plan for the LHD experimental hall and are carrying out development of wires, including an investigation of their mechanical properties and electrical insulation. This report describes the conceptual design of the superconducting bus-line for the LHD, and the results we obtained recently during the design and development of a full-scale demonstration facility. (orig.)

  18. Security awareness for public bus transportation : case studies of attacks against the Israeli public bus system.

    Science.gov (United States)

    2012-03-01

    This report presents 16 case studies of attacks planned or carried out against Israeli bus targets, along with statistical data on the number, frequency, and lethality of attacks against bus targets that have taken place in Israel since 1970 and duri...

  19. 77 FR 6178 - FY 2012 Discretionary Funding Opportunities: Bus and Bus Facilities Programs (State of Good...

    Science.gov (United States)

    2012-02-07

    ... not limited to: Rail, ferry, intercity bus and private transportation providers. In order to be..., intercity bus, and private transportation providers. In order to be eligible for funding, intermodal... automobile travel, improving the pedestrian environment of a community or, use of environmental design...

  20. Digital processing data communication systems (bus systems). Digitale Prozessdaten-Kommunikations-Systeme (Bus Systeme)

    Energy Technology Data Exchange (ETDEWEB)

    Fleck, K

    1980-01-01

    After an introduction to the technology of digital processing data communication systems there are the following chapters: digital communication of processing data in automation technology, the technology of biserial communication, the implementaiton of a bus system, the data transmission of the TDC-2000 system of Honeywell's and the process bus CS 275 in the automation system TELEPERM M of Siemens AG.

  1. Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes

    Science.gov (United States)

    Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

    2015-01-01

    Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes. PMID:26294903

  2. Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes.

    Science.gov (United States)

    Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

    2015-01-01

    Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes.

  3. Demand estimation of bus as a public transport based on gravity model

    Directory of Open Access Journals (Sweden)

    Asmael Noor

    2018-01-01

    Full Text Available Bus as a public transport is a suitable service to meet the travel demand between any two zones. Baghdad faced with severe traffic problems along with the development in city size and economy. Passengers have to wait lots of time during commutation to work because of the serious traffic jams. In the last years, rate of car ownership has increased as income levels have gone up and cars have become a preferable mode of transport. Bus, as the only public mode of transport available, is suffering from inconvenience, slowness, and inflexibility. A big emphasis must be given to the public transport system because it introduces an active utilization of limited resources, energy and land. This study determines the demand of public routes for buses using boarding / alighting values to generate a model and assign these demand values to the bus network. Five public routes were selected to collect the required data. Ride check and Point check survey was conducted for each selected route. The results of this study were public demand assigned to the selected bus routes, dwell time, load factor and headway. It is observed that R1 and R3 have the heaviest travel demand; they need special study to improve bus performance and make better transit. The model developed with only limited data available to predict travel demand will assist transportation planners and related agencies in decision making.

  4. An Extended IEEE 118-Bus Test System With High Renewable Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Ivonne; Martinez-Anido, Carlo Brancucci; Hodge, Bri-Mathias

    2018-01-01

    This article describes a new publicly available version of the IEEE 118-bus test system, named NREL-118. The database is based on the transmission representation (buses and lines) of the IEEE 118-bus test system, with a reconfigured generation representation using three regions of the US Western Interconnection from the latest Western Electricity Coordination Council (WECC) 2024 Common Case [1]. Time-synchronous hourly load, wind, and solar time series are provided for over one year (8784 hours). The public database presented and described in this manuscript will allow researchers to model a test power system using detailed transmission, generation, load, wind, and solar data. This database includes key additional features that add to the current IEEE 118-bus test model, such as: the inclusion of 10 generation technologies with different heat rate functions, minimum stable levels and ramping rates, GHG emissions rates, regulation and contingency reserves, and hourly time series data for one full year for load, wind and solar generation.

  5. Testing of Environmental Satellite Bus-Instrument Interfaces Using Engineering Models

    Science.gov (United States)

    Gagnier, Donald; Hayner, Rick; Nosek, Thomas; Roza, Michael; Hendershot, James E.; Razzaghi, Andrea I.

    2004-01-01

    This paper discusses the formulation and execution of a laboratory test of the electrical interfaces between multiple atmospheric scientific instruments and the spacecraft bus that carries them. The testing, performed in 2002, used engineering models of the instruments and the Aura spacecraft bus electronics. Aura is one of NASA s Earth Observatory System missions. The test was designed to evaluate the complex interfaces in the command and data handling subsystems prior to integration of the complete flight instruments on the spacecraft. A problem discovered during the flight integration phase of the observatory can cause significant cost and schedule impacts. The tests successfully revealed problems and led to their resolution before the full-up integration phase, saving significant cost and schedule. This approach could be beneficial for future environmental satellite programs involving the integration of multiple, complex scientific instruments onto a spacecraft bus.

  6. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  7. A life-cycle approach to technology, infrastructure, and climate policy decision making: Transitioning to plug-in hybrid electric vehicles and low-carbon electricity

    Science.gov (United States)

    Samaras, Constantine

    In order to mitigate the most severe effects of climate change, large global reductions in the current levels of anthropogenic greenhouse gas (GHG) emissions are required in this century to stabilize atmospheric carbon dioxide (CO2) concentrations at less than double pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC) fourth assessment report states that GHG emissions should be reduced to 50-80% of 2000 levels by 2050 to increase the likelihood of stabilizing atmospheric CO2 concentrations. In order to achieve the large GHG reductions by 2050 recommended by the IPCC, a fundamental shift and evolution will be required in the energy system. Because the electric power and transportation sectors represent the largest GHG emissions sources in the United States, a unique opportunity for coupling these systems via electrified transportation could achieve synergistic environmental (GHG emissions reductions) and energy security (petroleum displacement) benefits. Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a major role in reducing greenhouse gas emissions from the transport sector. However, this thesis finds that life cycle GHG emissions from PHEVs depend on the electricity source that is used to charge the battery, so meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. Power plants and their associated GHGs are long-lived, and this work argues that decisions made regarding new electricity supplies within the next ten years will affect the potential of PHEVs to play a role in a low-carbon future in the coming decades. This thesis investigates the life cycle engineering, economic, and policy decisions involved in transitioning to PHEVs and low-carbon electricity. The government has a vast array of policy options to promote low-carbon technologies, some of which have proven to be more successful than others. This thesis uses life

  8. Graphene/phase change material nanocomposites: light-driven, reversible electrical resistivity regulation via form-stable phase transitions.

    Science.gov (United States)

    Wang, Yunming; Mi, Hongyi; Zheng, Qifeng; Ma, Zhenqiang; Gong, Shaoqin

    2015-02-04

    Innovative photoresponsive materials are needed to address the complexity of optical control systems. Here, we report a new type of photoresponsive nanomaterial composed of graphene and a form-stable phase change material (PCM) that exhibited a 3 orders of magnitude change in electrical resistivity upon light illumination while retaining its overall original solid form at the macroscopic level. This dramatic change in electrical resistivity also occurred reversibly through the on/off control of light illumination. This was attributed to the reversible phase transition (i.e., melting/recrystallization) behavior of the microscopic crystalline domains present in the form-stable PCM. The reversible phase transition observed in the graphene/PCM nanocomposite was induced by a reversible temperature change through the on/off control of light illumination because graphene can effectively absorb light energy and convert it to thermal energy. In addition, this graphene/PCM nanocomposite also possessed excellent mechanical properties. Such photoresponsive materials have many potential applications, including flexible electronics.

  9. A smooth transition logit model of the effects of deregulation in the electricity market

    DEFF Research Database (Denmark)

    Hurn, A. Stan; Silvennoinen, Annastiina; Teräsvirta, Timo

    2016-01-01

    of the model are derived along with their asymptotic properties, together with a Lagrange multiplier test of the null hypothesis of linearity in the underlying latent index. The development of the STL model is motivated by the desire to assess the impact of deregulation in the Queensland electricity market...... and ascertain whether increased competition has resulted in significant changes in the behaviour of the spot price of electricity, specifically with respect to the occurrence of periodic abnormally high prices. The model allows the timing of any change to be endogenously determined and also market participants...

  10. Foreign direct investment (FDI) in energy/electricity projects in the economies in transition

    International Nuclear Information System (INIS)

    Brendow, K.

    1995-01-01

    Registered foreign direct investments (FDI) in energy/ electricity projects in central and eastern Europe and the CIS are weak and disappointing compared with expectations and business opportunities. In addition, energy FDI is highly concentrated in oil and gas exploration/extraction. FDI opportunities in electricity generation, transmission and distribution while being explored, have not been implemented, mostly for legislation restriction reasons towards foreign participation. The major issue appears to be the extent of privatization of this politically and socially sensitive industry. Progress are made in Hungary, Poland and the Czech Republic. A significant breakthrough depends on political stability, economic recovery and progress in privatization. 2 figs

  11. Synergistic interactions of dynamic ridesharing and battery electric vehicles land use, transit, and auto pricing policies.

    Science.gov (United States)

    2015-10-01

    It is widely recognized that new vehicle and fuel technology is necessary, but not sufficient, to meet deep greenhouse gas (GHG) : reductions goals for both the U.S. and the state of California. Demand management strategies (such as land use, transit...

  12. Forecasting of harmonics distortions in electric power systems, using impedance matrix of harmonic bus; Previsao de distorcoes harmonicas em sistemas eletricos de potencia, utilizando-se matriz impedancia de barra harmonica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Clider Adriane de Sousa

    1993-11-01

    The present work is a contribution to the study of harmonics in electric power systems. It presents a focus returned to the planning area, in the sense of evaluating in a qualitative way the possible situations of harmonic distortions of voltage that can occur when of the installation of electric loads with not-linear behaviors in a power system. Using the domain of the frequency, as well as a monophase treatment, it intends to present a computational method of simple and fast processing to be used for evaluation of these harmonic distortions of voltage in power systems. Its main characteristic is the methodology used for the treatment of the harmonic injections on the part of non-linear loads, that it allows to supply a previous diagnosis of the behavior of the system, before the presence of such loads, before even of its effective installation.

  13. 76 FR 31354 - Notice of Issuance of Final Determination Concerning the Transit Connect Electric Vehicle

    Science.gov (United States)

    2011-05-31

    ... are drilled into the glider and brackets are installed to support the battery pack and other electric assembly components. The fuel door of the glider is removed, assembled into a charge port, and the charge...-voltage battery is removed. Station 2: A U.S.-origin battery pack, U.S. engine bay wiring harness, German...

  14. Management of busbar costs and spending tradeoffs for the transition to competitive markets in electricity

    Energy Technology Data Exchange (ETDEWEB)

    Corio, M.R.; Boyd, G. [Applied Economic Research Co., Inc., New York, NY (United States)

    1995-09-01

    Competition is changing the fundamental basis for doing business in the electricity generation market. As the market moves toward competitive market conditions, electricity will be viewed increasingly as a commodity--not only supplied to customers within a utility`s service area, but brokered and marketed outside its area as well. With movement toward retail wheeling being considered in California, Michigan, and New York, it may soon become a reality as well. This means that a utility can no longer feel secure as the monopoly supplier of electricity within its own franchise area. To remain the main supplier in its current service area and compete for customers in other service areas, utilities will need to understand and examine all the components of ``busbar costs`` at its generating units. As competition drives the market to marginal costs, generating units with costs exceeding the market clearing price for electricity may soon have a limited role in the generation market. As the industry evolves, competition in the marketplace will force uneconomic plants to reduce costs or go out of business. This paper discusses results of studies addressing the evaluation of cost effectiveness, benchmarking of cost-efficiency, and development of marginal cost curves for busbar costs based on the development and aggregation of the three key measures which determine the cost and level of output (generation): (1) reliability; (2) heat rate; and (3) planned outage factor.

  15. Transition from steady to periodic liquid-metal magnetohydrodynamic flow in a sliding electrical contact

    Science.gov (United States)

    Talmage, Gita; Walker, John S.; Brown, Samuel H.; Sondergaard, Neal A.

    1993-09-01

    In homopolar motors and generators, large dc electric currents pass through the sliding electrical contacts between rotating copper disks (rotors) and static copper surfaces shrouding the rotor tips (stators). A liquid metal in the small radial gap between the rotor tip and concentric stator surface can provide a low-resistance, low-drag electrical contact. Since there is a strong magnetic field in the region of the electrical contacts, there are large electromagnetic body forces on the liquid metal. The primary, azimuthal motion consists of simple Couette flow, plus an electromagnetically driven flow with large extremes of the azimuthal velocity near the rotor corners. The secondary flow involves the radial and axial velocity components, is driven by the centrifugal force associated with the primary flow, and is opposed by the electromagnetic body force, so that the circulation varies inversely as the square of the magnetic-field strength. Three flow regimes are identified as the angular velocity Ω of the rotor is increased. For small Ω, the primary flow is decoupled from the secondary flow. As Ω increases, the secondary flow begins to convect the azimuthal-velocity peaks radially outward, which in turn changes the centrifugal force driving the secondary flow. At some critical value of Ω, the flow becomes periodic through the coupling of the primary and secondary flows. The azimuthal-velocity peaks begin to move radially in and out with an accompanying oscillation in the secondary-flow strength.

  16. Management of busbar costs and spending tradeoffs for the transition to competitive markets in electricity

    International Nuclear Information System (INIS)

    Corio, M.R.; Boyd, G.

    1995-01-01

    Competition is changing the fundamental basis for doing business in the electricity generation market. As the market moves toward competitive market conditions, electricity will be viewed increasingly as a commodity--not only supplied to customers within a utility's service area, but brokered and marketed outside its area as well. With movement toward retail wheeling being considered in California, Michigan, and New York, it may soon become a reality as well. This means that a utility can no longer feel secure as the monopoly supplier of electricity within its own franchise area. To remain the main supplier in its current service area and compete for customers in other service areas, utilities will need to understand and examine all the components of ''busbar costs'' at its generating units. As competition drives the market to marginal costs, generating units with costs exceeding the market clearing price for electricity may soon have a limited role in the generation market. As the industry evolves, competition in the marketplace will force uneconomic plants to reduce costs or go out of business. This paper discusses results of studies addressing the evaluation of cost effectiveness, benchmarking of cost-efficiency, and development of marginal cost curves for busbar costs based on the development and aggregation of the three key measures which determine the cost and level of output (generation): (1) reliability; (2) heat rate; and (3) planned outage factor

  17. 10 CFR 830 Major Modification Determination for the ATR Diesel Bus (E-3) and Switchgear Replacement

    International Nuclear Information System (INIS)

    Duckwitz, Noel

    2011-01-01

    Near term replacement of aging and obsolescent original ATR equipment has become important to ensure ATR capability in support of NE's long term national missions. To that end, a mission needs statement has been prepared for a non-major system acquisition which is comprised of three interdependent subprojects. The first project, subject of this determination, will replace the existent diesel-electrical bus (E-3) and associated switchgear. More specifically, INL proposes transitioning ATR to 100% commercial power with appropriate emergency backup to include: (1) Provide commercial power as the normal source of power to the ATR loads currently supplied by diesel-electric power. (2) Provide backup power to the critical ATR loads in the event of a loss of commercial power. (3) Replace obsolescent critical ATR power distribution equipment, e.g., switchgear, transformers, motor control centers, distribution panels. Completion of this and two other age-related projects (primary coolant pump and motor replacement and emergency firewater injection system replacement) will resolve major age related operational issues plus make a significant contribution in sustaining the ATR safety and reliability profile. The major modification criteria evaluation of the project pre-conceptual design identified several issues make the project a major modification: (1) Evaluation Criteria No.2 (Footprint change). The addition of a new PC-4 structure to the ATR Facility to house safety-related SSCs requires careful attention to maintaining adherence to applicable engineering and nuclear safety design criteria (e.g., structural qualification, fire suppression) to ensure no adverse impacts to the safety-related functions of the housed equipment. (2) Evaluation Criteria No.3 (Change of existing process). The change to the strategy for providing continuous reliable power to the safety-related emergency coolant pumps requires careful attention and analysis to ensure it meets a project primary

  18. Classifying the Diversity of Bus Mapping Systems

    Science.gov (United States)

    Said, Mohd Shahmy Mohd; Forrest, David

    2018-05-01

    This study represents the first stage of an investigation into understanding the nature of different approaches to mapping bus routes and bus network, and how they may best be applied in different public transport situations. In many cities, bus services represent an important facet of easing traffic congestion and reducing pollution. However, with the entrenched car culture in many countries, persuading people to change their mode of transport is a major challenge. To promote this modal shift, people need to know what services are available and where (and when) they go. Bus service maps provide an invaluable element of providing suitable public transport information, but are often overlooked by transport planners, and are under-researched by cartographers. The method here consists of the creation of a map evaluation form and performing assessment of published bus networks maps. The analyses were completed by a combination of quantitative and qualitative data analysis of various aspects of cartographic design and classification. This paper focuses on the resulting classification, which is illustrated by a series of examples. This classification will facilitate more in depth investigations into the details of cartographic design for such maps and help direct areas for user evaluation.

  19. The journey towards decarbonization: Exploring socio-technical transitions in the electricity sector in the province of Ontario (1885–2013) and potential low-carbon pathways

    International Nuclear Information System (INIS)

    Rosenbloom, Daniel; Meadowcroft, James

    2014-01-01

    This article employs the multi-level perspective on socio-technical transitions to explore the historical evolution of the electricity regime in the province of Ontario from 1885-2013 and to interpret the potential for future movement towards decarbonization. With an emphasis on the political and social dimensions of transitions, this analysis traces the key features influencing change within Ontario's electricity system over the past century. This paper uses multiple criteria (the phase of electrification; role of the electricity system in economic development; structures of ownership, market and regulation; dominant technologies; and the relative stability of arrangements) to characterize distinct regime configurations and periods of instability which separate relatively stable system orientations. Lessons are drawn from the historical case with implications for future decarbonization in the province, including the importance of: (1) residual momentum; (2) embedded guiding principles; and, (3) politico-economic coalitions. - Highlights: • Investigates transitions in the electricity sector using the multi-level perspective. • Explores the socio-technical evolution of the electricity system in Ontario. • Draws lessons relevant for low-carbon transitions. • Poses key questions for the development of low-carbon pathways in Ontario. • Provides insights on the political dimensions of low-carbon transitions

  20. Foreign direct investments (FDI) in energy and electricity projects in the economies in transition

    International Nuclear Information System (INIS)

    Brendow, K.

    1996-01-01

    Registered foreign direct investments (or equity finance) in energy and electricity projects in central and eastern Europe (CEE) and the Commonwealth of Independent States (CIS) presently stand at about US$ 3 billion (flows) and US$ 5.5 billion (stock). This is insignificant compared with world FDI and disappointing compared with expectations and business opportunities. In addition, energy FDI is concentrated in oil and gas exploration/extraction, primarily in Russia, Kazakhstan and Azerbaijan. FDI opportunities in electricity generation, transmission and distribution while being explored (see list), have not been implemented: legislation was either restrictive as regards foreign participation, or not yet finalized, or not yet enacted. The major issue at present appears to be the extent of privatisation of this politically and socially sensitive industry. 1995 will see progress in Hungary, Poland and the Czech Republic. Related FDI would, however, still be modest. A significant breakthrough depends on political stability, economic recovery and progress in privatisation. (author)

  1. VICbus: A standard inter-crate bus

    International Nuclear Information System (INIS)

    Parkman, C.F.

    1990-01-01

    VICbus is a standard inter-crate cable bus being developed by a working group of the ISO/IEC. Derived from an initiative of the VMEbus Working Group of ESONE, VICbus aims to provide users of multi-crate VMEbus and other backplane bus systems with a standard inter-crate connection. Multi-drop operation is provided for up to 31 devices on a cable of maximum 100 metres in length. Two data transfer protocols are specified, compelled (asynchronous) transfers for transparent interconnection of backplane bus systems (VMEbus in the first instance), and high-speed, non-compelled (synchronous) transfers between VICbus interfaces. A limited interrupt mechanism is specified, as well as simple, but efficient arbitration technique. Conventional technology is employed: copper cables, existing transcievers, and differential signal transmission, together with proven low-level protocols. Data transfer rates in excess of 30 Mbyte/s will be possible on a cable length of 30 metres

  2. The role of electricity storage and hydrogen technologies in enabling global low-carbon energy transitions

    OpenAIRE

    McPherson, M.; Johnson, N.; Strubegger, M.

    2018-01-01

    Previous studies have noted the importance of electricity storage and hydrogen technologies for enabling large-scale variable renewable energy (VRE) deployment in long-term climate change mitigation scenarios. However, global studies, which typically use integrated assessment models, assume a fixed cost trajectory for storage and hydrogen technologies; thereby ignoring the sensitivity of VRE deployment and/or mitigation costs to uncertainties in future storage and hydrogen technology costs. Y...

  3. Sustainable Energy Transitions in China: Renewable Options and Impacts on the Electricity System

    Directory of Open Access Journals (Sweden)

    Xiaoyang Sun

    2016-11-01

    Full Text Available Chinese energy consumption has been dominated by coal for decades, but this needs to change to protect the environment and mitigate anthropogenic climate change. Renewable energy development is needed to fulfil the Intended Nationally Determined Contribution (INDC for the post-2020 period, as stated on the 2015 United Nations Climate Change Conference in Paris. This paper reviews the potential of renewable energy in China and how it could be utilised to meet the INDC goals. A business-as-usual case and eight alternative scenarios with 40% renewable electricity are explored using the EnergyPLAN model to visualise out to the year 2030. Five criteria (total cost, total capacity, excess electricity, CO2 emissions, and direct job creation are used to assess the sustainability of the scenarios. The results indicate that renewables can meet the goal of a 20% share of non-fossil energy in primary energy and 40%–50% share of non-fossil energy in electricity power. The low nuclear-hydro power scenario is the most optimal scenario based on the used evaluation criteria. The Chinese government should implement new policies aimed at promoting integrated development of wind power and solar PV.

  4. Effect of Aspect Ratio on Electrical, Rheological and Glass Transition Properties of PC/MWCNT Nanocomposites.

    Science.gov (United States)

    Cruz, Heidy; Son, Younggon

    2018-02-01

    Since the discovery of carbon nanotubes (CNT), significant research works have focused on the application of CNT as conductive filler to polymer nanocomposites which can be used in several fields such as electrostatic dissipation (ESD), electrostatic painting and electromagnetic interference shielding (EMI-shielding). However, the main challenge in the large-scale manufacturing of this technology is the poor electrical conductivity of polymer nanocomposites produced by injection molding process. This study aims to investigate the effect of CNT aspect ratio in improving the electrical conductivity of injection molded nanocomposites. In this work, three types of multiwall carbon nanotubes with different lengths were melt-mixed with polycarbonate in a twin screw extruder followed by injection and compression molding. Results show that nanocomposites with higher CNT aspect ratio exhibit higher electrical conductivity. Longer nanotubes form a stronger conductive network during secondary agglomeration which can withstand the high shear forces during injection molding. Higher melt viscosity and storage modulus were observed in nanocomposites with higher CNT aspect ratio which is attributed to the effective constriction of polymer chains by longer nanotubes. It was also found that Tg of the composites increased with nanotube aspect ratio and the addition of CNT causes degradation which leads to the general Tg depression of polycarbonate.

  5. Sound transit climate risk reduction project.

    Science.gov (United States)

    2013-09-01

    The Climate Risk Reduction Project assessed how climate change may affect Sound Transit commuter rail, light rail, and express bus : services. The project identified potential climate change impacts on agency operations, assets, and long-term plannin...

  6. Risk factors affecting fatal bus accident severity: Their impact on different types of bus drivers.

    Science.gov (United States)

    Feng, Shumin; Li, Zhenning; Ci, Yusheng; Zhang, Guohui

    2016-01-01

    While the bus is generally considered to be a relatively safe means of transportation, the property losses and casualties caused by bus accidents, especially fatal ones, are far from negligible. The reasons for a driver to incur fatalities are different in each case, and it is essential to discover the underlying risk factors of bus fatality severity for different types of drivers in order to improve bus safety. The current study investigates the underlying risk factors of fatal bus accident severity to different types of drivers in the U.S. by estimating an ordered logistic model. Data for the analysis are retrieved from the Buses Involved in Fatal Accidents (BIFA) database from the USA for the years 2006-2010. Accidents are divided into three levels by counting their equivalent fatalities, and the drivers are classified into three clusters by the K-means cluster analysis. The analysis shows that some risk factors have the same impact on different types of drivers, they are: (a) season; (b) day of week; (c) time period; (d) number of vehicles involved; (e) land use; (f) manner of collision; (g) speed limit; (h) snow or ice surface condition; (i) school bus; (j) bus type and seating capacity; (k) driver's age; (l) driver's gender; (m) risky behaviors; and (n) restraint system. Results also show that some risk factors only have impact on the "young and elder drivers with history of traffic violations", they are: (a) section type; (b) number of lanes per direction; (c) roadway profile; (d) wet road surface; and (e) cyclist-bus accident. Notably, history of traffic violations has different impact on different types of bus drivers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Signs of Transition; Tekens van Transitie

    Energy Technology Data Exchange (ETDEWEB)

    Van Leenders, C.; Baidenmann, J.

    2010-05-15

    This book contains 14 inspiring experiences with making the energy system more sustainable that make clear that the energy transition is progressing. Two examples are provided for each of the seven themes: (1) Sustainable electricity (Agriport A7, Wind park Prinses Amalia); (2) Energy in the built environment (passive houses, conceptual building); (3) Chain efficiency (searching for CO2, process intensification); (4) New gas (biogas from manure, High efficiency boiler); (5) Sustainable mobility (electric driving, bus on biogas); (6) greenhouse as source of energy (closing the greenhouses, tomatoes on geothermal heat); and (7) green resources (biorefinery of grass, pyrolisis of biomass) [Dutch] Dit boek bevat veertien inspirerende ervaringen met verduurzaming van de energiehuishouding die duidelijk maken dat er voortgang zit in energietransitie. Er worden twee voorbeelden gegeven voor elk van de zeven thema's: (1) Duurzame Elektriciteit (Agriport A7, Windpark Prinses Amalia); (2) Energie in de Gebouwde Omgeving (Passiefhuizen, Conceptueel Bouwen); (3) Keten-Efficiency (Op zoek naar CO2, Procesintensificatie); (4) Nieuw Gas (Biogas uit mest, HR-e ketel); (5) Duurzame Mobiliteit (Elektrisch rijden, Bus op biogas); (6) Kas als Energiebron (De kassen sluiten, Tomaten op aardwarmte); en (7) Groene Grondstoffen (Bioraffinage van gras, Pyrolyse van biomassa)

  8. Fuel Cell Buses in U.S. Transit Fleets: Current Status 2011

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.; Gikakis, C.

    2011-11-01

    This status report, fifth in a series of annual status reports from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL), discusses the achievements and challenges of fuel cell propulsion for transit and summarizes the introduction of fuel cell transit buses in the United States. Progress this year includes an increase in the number of fuel cell electric buses (FCEBs), from 15 to 25, operating at eight transit agencies, as well as increased diversity of the fuel cell design options for transit buses. The report also provides an analysis of the combined results from fuel cell transit bus demonstrations evaluated by NREL with a focus on the most recent data through July 2011 including fuel cell power system reliability and durability; fuel economy; roadcall; and hydrogen fueling results. These evaluations cover 22 of the 25 FCEBs currently operating.

  9. Development and Evaluation of an Economic-Driving Assistance Program for Transit Vehicles

    Directory of Open Access Journals (Sweden)

    Baoxin Han

    2012-02-01

    Full Text Available This paper focuses on development and evaluation of an economic-driving assistance program for transit vehicles (EDTV which can minimize energy consumption, air pollution emission of buses, and improve the level of service of transit system as well. Taking advantage of the latest advances in information and communication technologies, the EDTV system can provide bus drivers with optimal recommended bus holding times at near-side bus stops and dynamic bus speed to adapt to the real-time traffic control plan at downstream intersections. In order to address the impacts of the stochastic variation of bus dwell time, the total link between adjacent intersections is divided into three parts: upstream of bus stop part; bus stop part; and downstream of bus stop part. The methods for calculating recommended parameters, including bus holding time and bus speed in each of the three parts are proposed based on real-time bus status and signal status at downstream intersections. A VISSIM-based simulation platform was designed and used for simulating and evaluating the proposed EDTV system. Extensive experimental analyses have shown that the proposed EDTV system can improve the performance of a transit system in terms of reducing fuel consumption, air pollution emissions and level of service of the transit system.

  10. Request-Centric Wireless Bus Information Management System

    Directory of Open Access Journals (Sweden)

    Ying-Chih Chen

    2016-11-01

    Full Text Available This invention relates to a wireless bus information management system, which includes bus stop and vehicle management subsystems. The management signals are transmittable between bus stops and the vehicle. Based on vehicle management signals, the bus stop management subsystem can obtain information about the bus route identification, the number of unoccupied seats, the intention to stop or not, etc. Similarly, with the bus stop management signals, the vehicle management subsystem can make the decision of stopping. Accordingly, when a passenger wants to get off the vehicle or there are unoccupied seats, the vehicle management subsystem will inform the bus stop management subsystem such that the passengers waiting at the bus stop may flexibly schedule their travel plan. The proposed distributed wireless system is detailed by a prototype implementation and a simulation analysis, which is shown to be feasible and scalable.

  11. Optical and electrical experiments at some transition-metal oxide foil-electrolyte interfaces

    International Nuclear Information System (INIS)

    Sari, S.O.; Ahlgren, W.L.

    1977-01-01

    Metal-oxide layers formed from transition-metal foils oxidized by heating in air have been examined for their photoelectrolytic response. The metals examined are Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, and Pt. Weak photoeffects are observed for oxide layers of all of these metals. Sizable light-dependent oxygen gas evolution rates are found in Ti and also in W oxides. The spectral dependence of the oxygen response in these compounds is investigated, and interpretation is given of these experiments

  12. Emergence of a phase transition for the required amount of storage in highly renewable electricity systems

    DEFF Research Database (Denmark)

    Jensen, Tue Vissing; Greiner, Martin

    2014-01-01

    -up of the required amount of storage, with renewable penetration being the control parameter and average relative storage filling level being the order parameter. A singularity appears for the required storage energy capacity at a renewable penetration determined by the parameters of the storage. For an ideal...... storage with no roundtrip losses the transition occurs at 100% renewable penetration. Moreover, the required storage energy capacity is strongly enhanced by temporal correlations on the synoptic weather time scale. A Markov process is proposed, which reproduces these findings....

  13. Optical absorption of carbon nanotube diodes: Strength of the electronic transitions and sensitivity to the electric field polarization

    Science.gov (United States)

    Mencarelli, Davide; Pierantoni, Luca; Rozzi, Tullio

    2008-03-01

    Aim of this work is to model electrostatically doped carbon nanotubes (CNT), which have recently proved to perform as ideal PN diodes, also showing photovoltaic properties. The new model is able to predict the optical absorption of semiconducting CNT as function of size and chirality. We justify theoretically, for the first time, the experimentally observed capability of CNTs to detect and select not only a well defined set of frequencies, as resulting from their discrete band structure, but also the polarization of the incident radiation. The analysis develops from an approach proposed in a recent contribution. The periodic structure of CNTs is formally modeled as a photonic crystal, that is characterized by means of numerical simulators. Longitudinal and transverse components of the electric field are shown to excite distinct interband transitions between well defined energy levels. Equivalently, for a given energy of the incident radiation, absorption may show polarization ratios strongly exceeding unity.

  14. Photoluminescence energy transitions in GaAs-Ga{sub 1-x}Al{sub x}As double quantum wells: Electric and magnetic fields and hydrostatic pressure effects

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, S.Y. [Grupo de Educacion en Ciencias Experimentales y Matematicas-GECEM, Facultad de Educacion, Universidad de Antioquia, AA 1226 Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque@fisica.udea.edu.c [Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia)

    2009-12-15

    The photoluminescence energy transitions in GaAs-Ga{sub 1-x}Al{sub x}As coupled double quantum wells are presented by considering the simultaneous effects of applied electric and magnetic fields and hydrostatic pressure. Calculations have been made in the framework of the effective mass and parabolic band approximations and using a variational procedure. The electric field is taken to be oriented along the growth direction of the heterostructure whereas for the magnetic field both in-plane and in-growth directions have been considered. The results show that the hydrostatic pressure and the applied electric field are two useful tools to tune the direct and indirect exciton transitions in such heterostructures. Our results are in good agreement with previous experimental findings in double quantum wells under applied electric field and hydrostatic pressure.

  15. Photoluminescence energy transitions in GaAs-Ga1-xAlxAs double quantum wells: Electric and magnetic fields and hydrostatic pressure effects

    International Nuclear Information System (INIS)

    Lopez, S.Y.; Mora-Ramos, M.E.; Duque, C.A.

    2009-01-01

    The photoluminescence energy transitions in GaAs-Ga 1-x Al x As coupled double quantum wells are presented by considering the simultaneous effects of applied electric and magnetic fields and hydrostatic pressure. Calculations have been made in the framework of the effective mass and parabolic band approximations and using a variational procedure. The electric field is taken to be oriented along the growth direction of the heterostructure whereas for the magnetic field both in-plane and in-growth directions have been considered. The results show that the hydrostatic pressure and the applied electric field are two useful tools to tune the direct and indirect exciton transitions in such heterostructures. Our results are in good agreement with previous experimental findings in double quantum wells under applied electric field and hydrostatic pressure.

  16. Security awareness for public bus transportation : case studies of attacks against the Israeli public bus system [research brief].

    Science.gov (United States)

    2012-03-01

    Government regulators and transportation operators of public bus systems are concerned about terrorist attacks. Bus attacks in Israel between late September 2000 and the end of 2006, a period known as the Second Intifada, are particularly well known....

  17. Electric properties and phase transition behavior in lead lanthanum zirconate stannate titanate ceramics with low zirconate content

    Science.gov (United States)

    Zeng, Tao; Lou, Qi-Wei; Chen, Xue-Feng; Zhang, Hong-Ling; Dong, Xian-Lin; Wang, Gen-Shui

    2015-11-01

    The phase transitions, dielectric properties, and polarization versus electric field (P-E) hysteresis loops of Pb0.97La0.02(Zr0.42Sn0.58-xTix)O3 (0.13≤ x ≤0.18) (PLZST) bulk ceramics were systematically investigated. This study exhibited a sequence of phase transitions by analyzing the change of the P-E hysteresis loops with increasing temperature. The antiferroelectric (AFE) to ferroelectric (FE) phase boundary of PLZST with the Zr content of 0.42 was found to locate at the Ti content between 0.14 and 0.15. This work is aimed to improve the ternary phase diagram of lanthanum-doped PZST with the Zr content of 0.42 and will be a good reference for seeking high energy storage density in the PLZST system with low-Zr content. Project supported by the National Natural Science Foundation of China (Grant Nos. 51202273, 11204304, and 11304334) and the Science and Technology Commission of Shanghai Municipality, China (Grant No. 14DZ2261000).

  18. Electric dipole f values for Fe II J=9/2->11/2^o transitions

    Science.gov (United States)

    Beck, Donald R.

    2007-06-01

    Relativistic configuration-interaction f values have been obtained for all transitions between the lowest 17 J=9/2 and the lowest 27 J=11/2^o levels. The 35 f values >0.01 have an average gauge agreement of 3.6% and generally agree well with the semi-empirical results of Raassen ootnotetextA. J. J. Raassen, ftp://ftp.wins.uva.nl/pub/orth/iron/FeII.E1 (1999).. The near degeneracy of many of the odd levels requires the introduction of small semi-empirical energy shifts ootnotetextD. R. Beck, Phys. Scr. 71, 447 (2005).. A systematic way of estimating radial convergence is discussed.

  19. Fully-Coupled Thermo-Electrical Modeling and Simulation of Transition Metal Oxide Memristors

    Energy Technology Data Exchange (ETDEWEB)

    Mamaluy, Denis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gao, Xujiao [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tierney, Brian David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Marinella, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mickel, Patrick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tierney, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Transition metal oxide (TMO) memristors have recently attracted special attention from the semiconductor industry and academia. Memristors are one of the strongest candidates to replace flash memory, and possibly DRAM and SRAM in the near future. Moreover, memristors have a high potential to enable beyond-CMOS technology advances in novel architectures for high performance computing (HPC). The utility of memristors has been demonstrated in reprogrammable logic (cross-bar switches), brain-inspired computing and in non-CMOS complementary logic. Indeed, the potential use of memristors as logic devices is especially important considering the inevitable end of CMOS technology scaling that is anticipated by 2025. In order to aid the on-going Sandia memristor fabrication effort with a memristor design tool and establish a clear physical picture of resistance switching in TMO memristors, we have created and validated with experimental data a simulation tool we name the Memristor Charge Transport (MCT) Simulator.

  20. Thermotropic Phase Transition of Benzodithiophene Copolymer Thin Films and Its Impact on Electrical and Photovoltaic Characteristics

    KAUST Repository

    Ko, Sangwon

    2015-02-24

    © 2015 American Chemical Society. We observed a thermotropic phase transition in poly[3,4-dihexyl thiophene-2,2′:5,6′-benzo[1,2-b:4,5-b′]dithiophene] (PDHBDT) thin films accompanied by a transition from a random orientation to an ordered lamellar phase via a nearly hexagonal lattice upon annealing. We demonstrate the effect of temperature-dependent molecular packing on charge carrier mobility (μ) in organic field-effect transistors (OFETs) and photovoltaic characteristics, such as exciton diffusion length (LD) and power conversion efficiency (PCE), in organic solar cells (OSCs) using PDHBDT. The μ was continuously improved with increasing annealing temperature and PDHBDT films annealed at 270 °C resulted in a maximum μ up to 0.46 cm2/(V s) (μavg = 0.22 cm2/(V s)), which is attributed to the well-ordered lamellar structure with a closer - stacking distance of 3.5 Å as shown by grazing incidence-angle X-ray diffraction (GIXD). On the other hand, PDHBDT films with a random molecular orientation are more effective in photovoltaic devices than films with an ordered hexagonal or lamellar phase based on current-voltage characteristics of PDHBDT/C60 bilayer solar cells. This observation corresponds to an enhanced dark current density (JD) and a decreased LD upon annealing. This study provides insight into the dependence of charge transport and photovoltaic characteristics on molecular packing in polymer semiconductors, which is crucial for the management of charge and energy transport in a range of organic optoelectronic devices.

  1. Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba sub 2 (In, M) sub 2 O sub 5 (M=Ga, Al)

    CERN Document Server

    Yamamura, H; Kakinuma, K; Mori, T; Haneda, H

    1999-01-01

    The brownmillerite solid-solution systems Ba sub 2 (In sub 1 sub - sub x M sub x) sub 2 O sub 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba sub 2 (In sub 1 sub - sub x Ga sub x) sub 2 O sub 5 system had orthorhombic symmetry in the composition range 0.0<=x<=0.2 and cubic symmetry in the range 0.3<=x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2<=x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These p...

  2. Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba2(In, M)2O5 (M=Ga, Al)

    International Nuclear Information System (INIS)

    Yamamura, Hiroshi; Hamazaki, Hirohumi; Kakinuma, Katsuyoshi; Mori, Toshiyuki; Haneda, Hajime

    1999-01-01

    The brownmillerite solid-solution systems Ba 2 (In 1-x M x ) 2 O 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba 2 (In 1-x Ga x ) 2 O 5 system had orthorhombic symmetry in the composition range 0.0≤x≤0.2 and cubic symmetry in the range 0.3≤x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2≤x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These phenomena are discussed in terms of disordering of the tetrahedral site in the brownmillerite structure, which is occupied by the smaller Ga 3+ or Al 3+ rather than ny In 3+

  3. Advanced Competencies for School Bus Drivers.

    Science.gov (United States)

    Illinois State Board of Education, Springfield.

    Four units are provided for formal classroom instruction in advanced competencies for school bus drivers in Illinois. Units cover passenger control, accidents and emergencies, detecting hazards, and first aid. Each unit contains some or all of the following components: table of contents; a list of objectives; informative material, including an…

  4. Functional Bus Driver-Pupil Passenger Relationships.

    Science.gov (United States)

    Farmer, Ernest

    1987-01-01

    Successful school bus drivers bring much more than mechanical know-how to the job. They develop good rapport with students while acting to bring undesirable student behavior under control. Drivers must also show an interest in students' welfare and have a good sense of humor. (MLH)

  5. School Bus Accidents: Reducing Incidents and Injuries

    Science.gov (United States)

    Mahoney, Daniel

    2009-01-01

    The number of children injured in nonfatal school bus accidents annually is more than double the number previously estimated. In Ohio alone, approximately 20,800 children younger than 18 were occupants of school buses that were involved in crashes in 2003 and 2004 (McGeehan 2007). Among those children, most had minor or no injuries. However, there…

  6. Bus safety study : a report to Congress.

    Science.gov (United States)

    2013-11-01

    Section 20021(b) of the Moving Ahead for Progress for the 21st Century (MAP-21) legislation requires the Secretary of Transportation : to submit a report of the results of a Bus Safety Study to the Committee on Banking, Housing, and Urban Affai...

  7. Technology Validation: Fuel Cell Bus Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, Leslie [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-02

    This presentation describing the FY 2016 accomplishments for the National Renewable Energy Laboratory's Fuel Cell Bus Evaluations project was presented at the U.S. Department of Energy Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting, June 7, 2016.

  8. Repeater For A Digital-Communication Bus

    Science.gov (United States)

    Torres-Guzman, Esteban; Olson, Stephen; Heaps, Tim

    1993-01-01

    Digital repeater circuit designed to extend range of communication on MIL-STD-1553 bus beyond original maximum allowable length of 300 ft. Circuit provides two-way communication, one way at time, and conforms to specifications of MIL-STD-1553. Crosstalk and instability eliminated.

  9. Energy DataBus (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2013-07-01

    NREL has developed the Energy DataBus, an open-sourced software that collects massive amounts of energy-related data at second-to-second intervals; stores it in a massive, scalable database; and turns it into useful information.

  10. The value of electric energy storage in electricity systems with high shares of wind and solar PV: the case of France in the energy transition

    International Nuclear Information System (INIS)

    Villavicencio, Manuel

    2017-01-01

    The adoption of ambitious targets for variable renewable energies (VRE) such as wind and solar has important effects on the technical and economic operation of power systems. Increasing shares of VRE will in particular require the deployment of more flexible and responsive technologies. Key flexibility providers in the scope are demand side management (DSM) and different forms of electric energy storage (EES) such as pumped hydroelectric (PHS), Li-ion batteries (Li-ion), and compressed air (CAES), among others. It have been previously showed how the value and the deployment of such new flexibility providers depended on the shares of VRE shares introduced into the system (Brijs et al., 2016; Van Stiphout et al., 2015; Villavicencio, 2017). Building on this works, this paper explores the value of storage in the context of a realistic Brownfield model calibrated on the existing French electricity system. In particular, this paper compares the value of storage (a) in a system corresponding to the target of 27% VRE production formulated by the French government in its 2015 Energy Transition Act by 2020 and (b) in a system corresponding to the target of 40% VRE production formulated in the same Act by 2030. The latter case will necessarily reflect the additional target which by 2025 limits the share of nuclear power to 50% of electricity production. In 2020, 4.7 GW of DSM are sufficient to provide the required flexibility and no EES investments will be needed. By 2030, however, in addition to a comparable level of DSM, 3.2 GW of additional EES investments are required. These storage solutions will generate an economic value of euro 350 million per year and will increases overall welfare by euro 670 million per year by 2030. The modeling yields a number of additional policy relevant results. First, limiting nuclear production will open opportunities for alternative base and mid-load providers, mainly gas, implying a threefold increase of CO_2 emissions compared to 2020

  11. Monopolies, liberalization, energy transition. Electricity market design between change and constancy; Monopole, Liberalisierung, Energiewende. Strommarktdesign zwischen Wandel und Konstanz

    Energy Technology Data Exchange (ETDEWEB)

    Grashof, Katherina; Zipp, Alexander [Hochschule fuer Technik und Wirtschaft (HTW), Saarbruecken (Germany). Abt. Energiemaerkte; Lechtenboehmer, Stefan [Wuppertal Institut fuer Klima Umwelt Energie (Germany). Forschungsgruppe 1: Zukuenftige Energie- und Mobilitaetsstrukturen; Jachmann, Henning [Zentrum fuer Sonnenenergie und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany); Wille-Haussmann, Bernhard [Fraunhofer-Institut fuer Solare Energiesysteme ISE, Freiburg (Germany). Elektrische Verteilnetze und Betriebsmittel; Reeg, Matthias [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Fachbereich Systemanalyse und Technikbewertung

    2015-09-15

    After a long period of stability, the electricity industry is in the past 15 years in a major state of flux. With the liberalization the change of area monopolies to competitively organized producer and consumer markets was pending. At present a very similar upheaval takes place, which is characterized by the transition from conventional to renewable power generation. But are the paradigms of each phase compatible and has plenty of still their right to exist, or is a modification necessary? The electricity market design of the future cannot designed on a blank sheet, but it must be taken into account existing structures. At the same time, the question must be answered whether the choice between regulatory or market-based approaches also differs with the possibility of precision of control. [German] Nach einer langen Phase der Stabilitaet ist die Stromwirtschaft in den vergangenen 15 Jahren stark in Bewegung geraten. Mit der Liberalisierung stand zunaechst der Wechsel von Gebietsmonopolen hin zu wettbewerblich organisierten Erzeuger- und Verbrauchermaerkten an. Derzeit findet ein ganz aehnlicher Umbruch statt, der vom Uebergang von konventioneller hin zu erneuerbarer Stromerzeugung gekennzeichnet ist. Aber sind die Paradigmen der einzelnen Phasen miteinander vereinbar und hat jede fuer sich noch immer ihre Daseinsberechtigung, oder ist hier eine Modifizierung notwendig? Das Strommarktdesign der Zukunft kann nicht auf einem leeren Blatt entworfen, sondern es muessen bestehende Strukturen beruecksichtigt werden. Gleichzeitig ist die Frage zu beantworten, ob die Wahl zwischen regulatorischen oder marktbasierten Ansaetzen sich auch anhand der mit ihnen moeglichen Praezision der Steuerung unterscheidet.

  12. No energy transition without a change of paradigm for electric grids

    International Nuclear Information System (INIS)

    Ober, Thomas; Meunier, Stephane

    2015-01-01

    The authors first indicate the three main levels of the French electric grid operation (a national transmission grid, regional distribution grids, and distribution to the final user) with their radial or tree-like structure. They briefly analyse the characteristics and impact of the integration of renewable energies: low power installations, wind and solar farms, strengths (close to consumption locations, reduction of grid losses, free primary energy) and raised problems (sizing of distribution networks, intermittency, and influence on conventional production planning). They discuss the implementation of new tools and devices such as the smart meter which can transmit various technical data, or a local steering of distribution networks. Renewable energies could then become a regulating element when they have been considered until now as a disturbing element. The authors finally evoke solutions aimed at reducing the use of peak means: a smoothed consumption, and the use of other production sources

  13. Recovery - Strategy to Accelerate U.S. Transition to Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Leach, Richard; LoGrasso, Joseph; Monterosso, Sandra

    2014-04-30

    The objective of this project was to develop Extended Range Electric Vehicle (EREV) advanced propulsion technology and demonstrate a fleet of 146 Volt EREVs to gather data on vehicle performance and infrastructure to understand the impacts on commercialization while also creating or retaining a significant number of jobs in the United States. This objective was achieved by developing and demonstrating EREVs in real world conditions with customers in several diverse locations across the United States and installing, demonstration and testing charging infrastructure while also continuing development on second generation EREV technology. The project completed the development of the Chevrolet Volt and placed the vehicle in the hands of consumers in diverse locations across the United States. This demonstration leveraged the unique telematics platform of OnStar, standard on all Chevrolet Volts, to capture the operating experience that lead to better understanding of customer usage. The project team included utility partners that installed, demonstrated and tested charging infrastructure located in home, workplace and public locations to understand installation issues, customer usage and interaction with the electric grid. Development and demonstration of advanced technologies such as smart charging, fast charging and battery to grid interface were completed. The recipient collected, analyzed and reported the data generated by the demonstration. The recipient also continued to advance the technology of the Chevrolet Volt technology by developing energy storage system enhancements for the next-generation vehicle. Information gathered from the first generation vehicle will be utilized to refine the technology to reduce cost and mass while also increasing energy storage capacity to enhance adoption of the second generation technology into the marketplace. The launch of the first generation Chevrolet Volt will provide additional opportunities to further enhance the RESS

  14. Stochastic Bus Dispatching Model untuk Optimalisasi Jumlah Bus Transjakarta Koridor 3

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2011-12-01

    Full Text Available The increasing number of road user causing traffic jam finds out a way, busway. However, in its implementation, the number of fleet available does not enough to take the passengers. It results in the an amassed of passengers at several bus stops. This leads to passenger dissatisfaction satisfaction which eventually causes Transjakarta users to reuse private cars. Definitely this situation may builds up traffic jams. Stochastic Bus Dispatching Model is used to simulate public transportation that operates regularly. 

  15. Role of Defects and Adsorbed Water Film in Influencing the Electrical, Optical and Catalytic Properties of Transition Metal Oxides

    Science.gov (United States)

    Wang, Qi

    Transition metal oxides (TMOs) constitute a large group of materials that exhibit a wide range of optical, electrical, electrochemical, dielectric and catalytic properties, and thus making them highly regarded as promising materials for a variety of applications in next generation electronic, optoelectronic, catalytic, photonic, energy storage and energy conversion devices. Some of the unique properties of TMOs are their strong electron-electron correlations that exists between the valence electrons of narrow d- or f-shells and their ability to exist in variety of oxidation states. This gives TMOs an enormous range of fascinating electronic and other physical properties. Many of these remarkable properties of TMOs arises from the complex surface charge transfer processes at the oxide surface/electrochemical redox species interface and non-stoichiometry due to the presence of lattice vacancies that may cause significant perturbation to the electronic structure of the material. Stoichiometry, oxidation state of the metal center and lattice vacancy defects all play important roles in affecting the physical properties, electronic structures, device behavior and other functional properties of TMOs. However, the underlying relationships between them is not clearly known. For instance, the exchange of electrons between adsorbates and defects can lead to the passivation of existing defect states or formation of new defects, both of which affect defect equilibria, and consequently, functional properties. In depth understanding of the role of lattice defects on the electrical, catalytic and optical properties of TMOs is central to further expansion of the technological applications of TMO based devices. The focus of this work is to elucidate the interactions of vacancy defects with various electrochemical adsorbates in TMOs. The ability to directly probe the interactions of vacancy defects with gas and liquid phase species under in-operando conditions is highly desirable to

  16. Optimum power quality service in multi-bus microgrid systems

    DEFF Research Database (Denmark)

    Meng, Lexuan; Guerrero, Josep M.

    2017-01-01

    Power quality requirements for different consumers and electric equipment are distinguished. Conventionally a common power quality standard is applied to the whole power grid inducing debate between several sides, including consumers, generation sites and technical commissions. Customized power...... quality standard settings for different consumers become a widely accepted solution. The main challenge is on the proper regulation of power quality in different areas. This paper considers a multi-bus microgrid system where the power quality in each has flexible and individual standard. Distributed...... generators are utilized to provide power quality regulation functions. An optimization method based strategy is proposed and implemented with the power converter control system. A general mathematical model is established which can be used in the optimization problem for evaluating the objective function...

  17. Electrical Conductivity, Relaxation and the Glass Transition: A New Look at a Familiar Phenomenon

    Science.gov (United States)

    Angel, Paul W.; Cooper, Alfred R.; DeGuire, Mark R.

    1996-01-01

    Annealed samples from a single melt of a 10 mol% K2O-90SiO2 glass were reheated to temperatures ranging from 450 to 800 C, held isothermally for 20 min, and then quenched in either air or a silicon oil bath. The complex impedance of both the annealed and quenched samples was measured as a function of temperature from 120 to 250 C using ac impedance spectroscopy from 1 Hz to 1 MHz. The dc conductivity, sigma(sub dc), was measured from the low frequency intercept of depressed semicircle fits to the complex impedance data. When the sigma(sub dc) at 150 C was plotted against soak temperature, the results fell into three separate regions that are explained in terms of the glass structural relaxation time, tau(sub S). This sigma(sub dc) plot provides a new way to look the glass transition range, Delta T(sub r). In addition, sigma(sub dc) was measured for different soak times at 550 C, from which an average relaxation time of 7.3 min was calculated. It was found that the size and position of the Delta T(sub r) is controlled by both the soak time and cooling rate.

  18. The Effects of Bus Ridership on Airborne Particulate Matter (PM10) Concentrations

    OpenAIRE

    Jaeseok Her; Sungjin Park; Jae Seung Lee

    2016-01-01

    Air pollution caused by rapid urbanization and the increased use of private vehicles seriously affects citizens’ health. In order to alleviate air pollution, many cities have replaced diesel buses with compressed natural gas (CNG) buses that emit less exhaust gas. Urban planning strategies such as transit-oriented development (TOD) posit that reducing private vehicle use and increasing public transportation use would reduce air pollution levels. The present study examined the effects of bus r...

  19. Localized electric field induced transition and miniaturization of two-phase flow patterns inside microchannels.

    Science.gov (United States)

    Sharma, Abhinav; Tiwari, Vijeet; Kumar, Vineet; Mandal, Tapas Kumar; Bandyopadhyay, Dipankar

    2014-10-01

    Strategic application of external electrostatic field on a pressure-driven two-phase flow inside a microchannel can transform the stratified or slug flow patterns into droplets. The localized electrohydrodynamic stress at the interface of the immiscible liquids can engender a liquid-dielectrophoretic deformation, which disrupts the balance of the viscous, capillary, and inertial forces of a pressure-driven flow to engender such flow morphologies. Interestingly, the size, shape, and frequency of the droplets can be tuned by varying the field intensity, location of the electric field, surface properties of the channel or fluids, viscosity ratio of the fluids, and the flow ratio of the phases. Higher field intensity with lower interfacial tension is found to facilitate the oil droplet formation with a higher throughput inside the hydrophilic microchannels. The method is successful in breaking down the regular pressure-driven flow patterns even when the fluid inlets are exchanged in the microchannel. The simulations identify the conditions to develop interesting flow morphologies, such as (i) an array of miniaturized spherical or hemispherical or elongated oil drops in continuous water phase, (ii) "oil-in-water" microemulsion with varying size and shape of oil droplets. The results reported can be of significance in improving the efficiency of multiphase microreactors where the flow patterns composed of droplets are preferred because of the availability of higher interfacial area for reactions or heat and mass exchange. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Autonomous Navigation and Obstacle Avoidance of a Micro-Bus

    Directory of Open Access Journals (Sweden)

    Carlos Fernández

    2013-04-01

    Full Text Available At present, the topic of automated vehicles is one of the most promising research areas in the field of Intelligent Transportation Systems (ITS. The use of automated vehicles for public transportation also contributes to reductions in congestion levels and to improvements in traffic flow. Moreover, electrical public autonomous vehicles are environmentally friendly, provide better air quality and contribute to energy conservation. The driverless public transportation systems, which are at present operating in some airports and train stations, are restricted to dedicated roads and exhibit serious trouble dynamically avoiding obstacles in the trajectory. In this paper, an electric autonomous mini-bus is presented. All datasets used in this article were collected during the experiments carried out in the demonstration event of the 2012 IEEE Intelligent Vehicles Symposium that took place in Alcalá de Henares (Spain. The demonstration consisted of a route 725 metres long containing a list of latitude-longitude points (waypoints. The mini-bus was capable of driving autonomously from one waypoint to another using a GPS sensor. Furthermore, the vehicle is provided with a multi-beam Laser Imaging Detection and Ranging (LIDAR sensor for surrounding reconstruction and obstacle detection. When an obstacle is detected in the planned path, the planned route is modified in order to avoid the obstacle and continue its way to the end of the mission. On the demonstration day, a total of 196 attendees had the opportunity to get a ride on the vehicles. A total of 28 laps were successfully completed in full autonomous mode in a private circuit located in the National Institute for Aerospace Research (INTA, Spain. In other words, the system completed 20.3 km of driverless navigation and obstacle avoidance.