2,023 research outputs found

    The Prospects for Hybrid Electric Vehicles, 2005-2020: Results of a Delphi Study

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    The introduction of Toyota's hybrid electric vehicle (HEV), the Prius, in Japan has generated considerable interest in HEV technology among US automotive experts. In a follow-up survey to Argonne National Laboratory's two-stage Delphi Study on electric and hybrid electric vehicles (EVs and HEVs) during 1994-1996, Argonne researchers gathered the latest opinions of automotive experts on the future ''top-selling'' HEV attributes and costs. The experts predicted that HEVs would have a spark-ignition gasoline engine as a power plant in 2005 and a fuel cell power plant by 2020. The projected 2020 fuel shares were about equal for gasoline and hydrogen, with methanol a distant third. In 2020, HEVs are predicted to have series-drive, moderate battery-alone range and cost significantly more than conventional vehicles (CVs). The HEV is projected to cost 66% more than a $20,000 CV initially and 33% more by 2020. Survey respondents view batteries as the component that contributes the most to the HEV cost increment. The mean projection for battery-alone range is 49 km in 2005, 70 km in 2010, and 92 km in 2020. Responding to a question relating to their personal vision of the most desirable HEV and its likely characteristics when introduced in the US market in the next decade, the experts predicted their ''vision'' HEV to have attributes very similar to those of the ''top-selling'' HEV. However, the ''vision'' HEV would cost significantly less. The experts projected attributes of three leading batteries for HEVs and projected acceleration times on battery power alone. The resulting battery packs are evaluated, and their initial and replacement costs are analyzed. These and several other opinions are summarized

    Random matrix ensemble with random two-body interactions in presence of a mean-field for spin one boson systems

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    For mm number of bosons, carrying spin (SS=1) degree of freedom, in Ω\Omega number of single particle orbitals, each triply degenerate, we introduce and analyze embedded Gaussian orthogonal ensemble of random matrices generated by random two-body interactions that are spin (S) scalar [BEGOE(2)-S1S1]. The embedding algebra is U(3)⊃G⊃G1⊗SO(3)U(3) \supset G \supset G1 \otimes SO(3) with SO(3) generating spin SS. A method for constructing the ensembles in fixed-(mm, SS) space has been developed. Numerical calculations show that the form of the fixed-(mm, SS) density of states is close to Gaussian and level fluctuations follow GOE. Propagation formulas for the fixed-(mm, SS) space energy centroids and spectral variances are derived for a general one plus two-body Hamiltonian preserving spin. In addition to these, we also introduce two different pairing symmetry algebras in the space defined by BEGOE(2)-S1S1 and the structure of ground states is studied for each paring symmetry.Comment: 22 pages, 6 figure

    Asymmetric transfer hydrogenation of acetophenone derivatives using 2-benzyl-tethered ruthenium (II)/TsDPEN complexes bearing η6-(p-OR) (R = H, iPr, Bn, Ph) ligands

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    A series of 4′-OR (R = H, iPr, Bn, Ph) substituted ruthenium (II) biphenyl TsDPEN complexes are described; the complexes are accessed via an operationally simple and reliable two-step ligand synthesis followed by ligation to the ruthenium (II) centre. We report the preliminary asymmetric transfer hydrogenation (ATH) results on a range of primarily acetophenone derivatives with these new complexes using FA/TEA (5:2) as a reducing agent; the results confirm that these catalysts are capable of reducing the substrates within 48 h with excellent enantioselectivities

    Higher order antibunching is not a rare phenomenon

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    Since the introduction of higher order nonclassical effects, higher order squeezing has been reported in a number of different physical systems but higher order antibunching is predicted only in three particular cases. In the present work, we have shown that the higher order antibunching is not a rare phenomenon rather it can be seen in many simple optical processes. To establish our claim, we have shown it in six wave mixing process, four wave mixing process and in second harmonic generation process.Comment: 6 pages, no figure, Latex 2

    Effect of omega-3 fatty acids enriched diet on semen characteristics in Marwari horses

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    The effect of w-3 fatty acid supplementation in the diet on various characteristics of fresh and frozen semen was investigated in Marwari horses. Stallions (6) were fed a standard diet daily from week –13 to week 0 (pre- supplementation phase) followed by supplementation of fish oil, a rich source of n-3 PUFA @64 mg/kg BW from week 1 to 14 (fish oil treatment phase) in diets. Ejaculates were collected from all the stallions on weekly basis from week –5 to 0 and week 9 to 14 during pre-supplementation and fish oil treatment phase, respectively. Effect of n-3 PUFA on ejaculate volume, color and consistency; total and progressive sperm motility, seminal pH, sperm concentration, live sperm and abnormal sperm in fresh semen was non-significant. Similarly, there was no change in the percentage of sperm PTM, HOS reacted sperm, live and abnormal sperm in frozen semen. It was concluded that dietary n-3 PUFA supplementation @64mg/ kg BW to horses for 14 weeks did not affect the semen quality. However, the beneficial effects of n-3 PUFA on semen quality may require longer period of supplementation

    Effective Field Theories

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    Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low ultraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically,the idea is to integrate out the high frequency components of fields. This requires the choice of a "blockspin",i.e. the specification of a low frequency field as a function of the fundamental fields. These blockspins will be the fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspins in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels \A from coarse to fine grid in addition to the averaging kernels CC which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The constraint effective potential) is of particular interest. In a Higgs model it yields the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data.Comment: 45 pages, 9 figs., preprint DESY 92-070 (figs. 3-9 added in ps format

    Evaluation of pearlmillet germplasm from Rajasthan

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    A set of 380 accessions of pearlmilleet Pennisetum americanum (Linn.) K. Schum = P. typhoides (Burm. f.) Stapf and C.E. Hubb. collected from Rajasthan during 1977 and 1982, evaluated at Patancheru, Hyderabad, during the rainy and post-rainy seasons showed desirable traits like early-maturity, good tillering, drought tolerance and adaptation to arid and semi-arid conditions. In general, they flowered in 60 days, grew tall (200 cm) and produced short (22 cm) but many (3.3) spikes during the rainy season. 'Jakhrana', 'Sulkhania', 'Gullista', 'Karauli' and 'Barmer' were found to be more advanced as they produce basal tillers, longer spikes with non-shattering spikelets and small glumes that partly covered the grain. 'Chadi' and 'Desert' types produced several nodal tillers with sequential maturity of spikes with shattering spikelets having glumes that almost covered the grain
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