733 research outputs found

    Phase 1 of the near term hybrid passenger vehicle development program. Appendix B: Trade-off studies, volume 1

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    Tradeoff study activities and the analysis process used are described with emphasis on (1) review of the alternatives; (2) vehicle architecture; and (3) evaluation of the propulsion system alternatives; interim results are presented for the basic hybrid vehicle characterization; vehicle scheme development; propulsion system power and transmission ratios; vehicle weight; energy consumption and emissions; performance; production costs; reliability, availability and maintainability; life cycle costs, and operational quality. The final vehicle conceptual design is examined

    Phase 1 of the near term hybrid passenger vehicle development program, appendix A. Mission analysis and performance specification studies. Volume 2: Appendices

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    A handy reference for JPL minimum requirements and guidelines is presented as well as information on the use of the fundamental information source represented by the Nationwide Personal Transportation Survey. Data on U.S. demographic statistics and highway speeds are included along with methodology for normal parameters evaluation, synthesis of daily distance distributions, and projection of car ownership distributions. The synthesis of tentative mission quantification results, of intermediate mission quantification results, and of mission quantification parameters are considered and 1985 in place fleet fuel economy data are included

    Phase 1 of the near term hybrid passenger vehicles development program. Appendix A: Mission analysis and performance specification studies, volume 1

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    Applicable data was categorized and processed according to vehicle usage and trip parameters with consideration of payload (cargo, people, size) and driving cycles. A mission that maximizes the fuel potential savings for the total 1985 vehicle fleet was selected. Mission requirements that have a bearing on conventional and hybrid vehicle performance and characteristics were identified and formulated and a reference ICE vehicle was selected that meets or exceeds all requirements while maintaining within applicable constraints. Specifications for vehicle performance were established based on mission requirements, mission related vehicle characteristics, and fuel consumption

    Phase 1 of the near term hybrid passenger vehicle development program. Appendix D: Sensitivity analysis

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    Data are presented on the sensitivity of: (1) mission analysis results to the boundary values given for number of passenger cars and average annual vehicle miles traveled per car; (2) vehicle characteristics and performance to specifications; and (3) tradeoff study results to the expected parameters

    Phase 1 of the near term hybrid passenger vehicle development program. Appendix B: Trade-off studies. Volume 2: Appendices

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    The SPEC '78 computer program which consists of mathematical simulations of any vehicle component and external environment is described as are configuration alternatives for the propulsion system. Preliminary assessments of the fundamental characteristics of the lead-acid and sodium-sulfur batteries are included and procedures are given for estimating the cost of a new vehicle in mass production

    Robustness of solutions to the capacitated facility location problem with uncertain demand

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    We investigate the properties of robust solutions of the Capacitated Facility Location Problem with uncertain demand. We show that the monotonic behavior of the price of robustness is not guaranteed, and therefore that one cannot discriminate among alternative robust solutions by simply relying on the trade-off price-vs-robustness. Furthermore, we report a computational study on benchmark instances from the literature and on instances derived from a real-world application, which demonstrates the validity in practice of our findings

    Hormonal responses to water deficit in cambial tissues of Populus alba L.

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    Changes of the concentration of bioactive gibberellins and abscisic acid in the cambial region of white poplar (Populus alba L.) were investigated in one-year-old plants, to highlight how these phytohormone signals are modulated in response to water deficit. Plants were cultivated in pots outdoor and, at the time of maximum cambial growth (T0), irrigation was withdrawn for 8 d, inducing a mild water deficit, thus mimicking a condition that is recurrent in mediterranean climates when white poplar attains its maximum growth rate. The water deficit was suspended by resuming irrigation (Tmax), throughout a recovery period of two weeks (Trec). Cambial tissues were sampled at T0, Tmax and Trec. Significant changes of leaf and stem relative water content, leaf water potential, stomatal conductance, transpiration, carbon assimilation, stem shrinkage and leaf number were induced by soil water shortage, which also negatively affected cambium development. Nevertheless, these responses were almost fully reversed following the resumption of irrigation. Water deficit induced the accumulation of large amounts of abscisic acid in cambial tissues, but the hormone was brought back to pre-stress levels after the recovery period. With regard to bioactive gibberellins, GA1 was several fold more abundant than GA4 and reached the greatest level in the plants recovering from the water status imbalance. The possible functions of gibberellins and abscisic acid in the response of cambial tissues to water deficit are discussed in view of the known physiological roles and molecular mechanisms of action of these hormonal signals

    Integrated complementary graphene inverter

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    The operation of a digital logic inverter consisting of one p- and one n-type graphene transistor integrated on the same sheet of monolayer graphene is demonstrated. The type of one of the transistors was inverted by moving its Dirac point to lower gate voltages via selective electrical annealing. Boolean inversion is obtained by operating the transistors between their Dirac points. The fabricated inverter represents an important step towards the development of digital integrated circuits on graphene.Comment: 4 pages, 4 figure
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