14,649 research outputs found

    Aesthetic approach to green transportation planning in tourism with design factors

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    Green transportation technology has become a new paradigm in transportation engineeringfields over the whole world. Most attention, however, has been paid to mitigate greenhousegases or energy consumption, seldom reported pro-environment design in aesthetic aspect. Itis well known that a proper design of train enhances traveler satisfaction and contributes todemand increase in public transportation. Hence, aesthetic factors should be consideredsignificantly. However, a difficult problem for reflecting aesthetic aspect is that there is noclear design standard for railway to reflect aesthetic features. This paper aims to suggestaesthetic factors to be guidance of rail transit planning in tourist attractions. We begin bydefining a term ‘aesthetic in railway system’ based on literature and empirical review. In thispaper, the definition is divided into two complementary views: (I) Sight-seeing mechanismfrom inside to outside. (II) Vehicle exterior design harmonized with surrounding environment.Based on the definitions, design factors are suggested: window size, speed, routes, type oftrack, color, and size of train system. Each factor is explained with its standard. A result of evaluating rail transit with the factors shows that wireless tram is the most suitable transit for tourism. Limitations and improvements of the study are also suggested.Keywords: Green transportation technology; Public transportation; Aesthetic factor; Touris

    Particle acceleration and the origin of gamma-ray emission from Fermi Bubbles

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    Fermi LAT has discovered two extended gamma-ray bubbles above and below the galactic plane. We propose that their origin is due to the energy release in the Galactic center (GC) as a result of quasi-periodic star accretion onto the central black hole. Shocks generated by these processes propagate into the Galactic halo and accelerate particles there. We show that electrons accelerated up to ~10 TeV may be responsible for the observed gamma-ray emission of the bubbles as a result of inverse Compton (IC) scattering on the relic photons. We also suggest that the Bubble could generate the flux of CR protons at energies > 10^15 eV because the shocks in the Bubble have much larger length scales and longer lifetimes in comparison with those in SNRs. This may explain the the CR spectrum above the knee.Comment: 5 pages, 4 figures. Expanded version of the contribution to the 32nd ICRC, Beijing, #0589. To appear in the proceeding

    A Prediction of Reliability of Suction Valve in Reciprocating Compressor

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    Bulk and surface electronic properties of SmB6: a hard x-ray photoelectron spectroscopy study

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    We have carried out bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES) measurements on in-situ cleaved and ex-situ polished SmB6 single crystals. Using the multiplet-structure in the Sm 3d core level spectra, we determined reliably that the valence of Sm in bulk SmB6 is close to 2.55 at ~5 K. Temperature dependent measurements revealed that the Sm valence gradually increases to 2.64 at 300 K. From a detailed line shape analysis we can clearly observe that not only the J=0 but also the J=1 state of the Sm 4f 6 configuration becomes occupied at elevated temperatures. Making use of the polarization dependence, we were able to identify and extract the Sm 4f spectral weight of the bulk material. Finally, we revealed that the oxidized or chemically damaged surface region of the ex-situ polished SmB6 single crystal is surprisingly thin, about 1 nm only.Comment: 11 pages, 8 figure

    Resonance Model of πΔ→YK\pi \Delta \rightarrow Y K for Kaon Production in Heavy Ion Collisions

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    The elementary production cross sections πΔ→YK\pi \Delta \rightarrow Y K (Y=Σ,  Λ)(Y=\Sigma,\,\, \Lambda) and πN→YK\pi N \rightarrow Y K are needed to describe kaon production in heavy ion collisions. The πN→YK\pi N \rightarrow Y K reactions were studied previously by a resonance model. The model can explain the experimental data quite well \cite{tsu}. In this article, the total cross sections πΔ→YK\pi \Delta \rightarrow Y K at intermediate energies (from the kaon production threshold to3 GeV of πΔ\pi \Delta center-of-mass energy) are calculated for the first time using the same resonance model. The resonances, N(1710) I(JP)=12(12+)N(1710)\,I(J^P) = \frac{1}{2}(\frac{1}{2}^+) and N(1720) 12(32+)N(1720)\, \frac{1}{2} (\frac{3}{2}^+) for the πΔ→ΣK\pi \Delta \rightarrow \Sigma K reactions, and N(1650) 12(12−)N(1650)\, \frac{1}{2} (\frac{1}{2}^-), N(1710) 12(12+)N(1710)\, \frac{1}{2} (\frac{1}{2}^+) and N(1720) 12(32+)N(1720)\, \frac{1}{2} (\frac{3}{2}^+) for the πΔ→ΛK\pi \Delta \rightarrow \Lambda K reactions are taken into account coherently as the intermediate states in the calculations. Also t-channel K∗(892)12(1−)K^*(892) \frac{1}{2}(1^-) vector meson exchange is included. The results show that K∗(892)K^*(892) exchange is neglegible for the πΔ→ΣK\pi \Delta \rightarrow \Sigma K reactions, whereas this meson does not contribute to the πΔ→ΛK\pi \Delta \rightarrow \Lambda K reactions. Furthemore, the πΔ→YK\pi \Delta \rightarrow Y K contributions to kaon production in heavy ion collisions are not only non-neglegible but also very different from the πN→YK\pi N \rightarrow Y K reactions. An argument valid for πN→YK\pi N \rightarrow Y K cannot be extended to πΔ→YK\pi \Delta \rightarrow Y K reactions. Therefore, cross sections for πΔ→YK\pi \Delta \rightarrow Y K including correctly the different isospins must beComment: ( Replaced with corrections of printing errors in the Table. ) 15 pages, Latex file with 4 figures, 1 figure is included in the text. A compressed uuencode file for 3 figures is appended. (A figure file format was changed.) Also available upon reques

    Report of the 1988 2-D Intercomparison Workshop, chapter 3

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    Several factors contribute to the errors encountered. With the exception of the line-by-line model, all of the models employ simplifying assumptions that place fundamental limits on their accuracy and range of validity. For example, all 2-D modeling groups use the diffusivity factor approximation. This approximation produces little error in tropospheric H2O and CO2 cooling rates, but can produce significant errors in CO2 and O3 cooling rates at the stratopause. All models suffer from fundamental uncertainties in shapes and strengths of spectral lines. Thermal flux algorithms being used in 2-D tracer tranport models produce cooling rates that differ by as much as 40 percent for the same input model atmosphere. Disagreements of this magnitude are important since the thermal cooling rates must be subtracted from the almost-equal solar heating rates to derive the net radiative heating rates and the 2-D model diabatic circulation. For much of the annual cycle, the net radiative heating rates are comparable in magnitude to the cooling rate differences described. Many of the models underestimate the cooling rates in the middle and lower stratosphere. The consequences of these errors for the net heating rates and the diabatic circulation will depend on their meridional structure, which was not tested here. Other models underestimate the cooling near 1 mbar. Suchs errors pose potential problems for future interactive ozone assessment studies, since they could produce artificially-high temperatures and increased O3 destruction at these levels. These concerns suggest that a great deal of work is needed to improve the performance of thermal cooling rate algorithms used in the 2-D tracer transport models

    Measurements of NO and total reactive odd-nitrogen, NOy, in the Antarctic stratosphere

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    Measurements of NO and total reactive N, NOy, were made as part of the Airborne Antarctic Ozone Experiment conducted in Punta Arenas, Chile during Aug. and Sept. 1987. The total reactive N reservoir includes the species NO, NO2, NO3, N2 O5, HNO3, and ClONO2. The instrument was located on board the NASA ER2 aircraft which conducted 12 flights over the Antarctic continent reaching altitudes of 18 km at 72 deg S latitude. The NOy technique utilized the conversion of component NOy species to NO on a gold catalyst and the subsequent detection of NO by the chemiluminescence reaction of NO with ozone. Since the inlet sample line is heated and the catalyst operates at 300 C, NOy incorporated in aerosols evaporates and is converted to NO. NO was measured on two separate flights by removing the catalyst from the sample inlet line

    Long-range interactions in the effective low energy Hamiltonian of Sr2IrO4: a core level resonant inelastic x-ray scattering study

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    We have investigated the electronic structure of Sr2IrO4 using core level resonant inelastic x-ray scattering. The experimental spectra can be well reproduced using ab initio density functional theory based multiplet ligand field theory calculations, thereby validating these calculations. We found that the low-energy, effective Ir t2g orbitals are practically degenerate in energy. We uncovered that covalency in Sr2IrO4, and generally in iridates, is very large with substantial oxygen ligand hole character in the Ir t2g Wannier orbitals. This has far reaching consequences, as not only the onsite crystal-field energies are determined by the long range crystal-structure, but, more significantly, magnetic exchange interactions will have long range distance dependent anisotropies in the spin direction. These findings set constraints and show pathways for the design of d^5 materials that can host compass-like magnetic interactions

    Coupling Processes Between Atmospheric Chemistry and Climate

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    This is the first semi-annual report for NAS5-97039 summarizing work performed for January 1997 through June 1997. Work in this project is related to NAS1-20666, also funded by NASA ACMAP. The work funded in this project also benefits from work at AER associated with the AER three-dimensional isentropic transport model funded by NASA AEAP and the AER two-dimensional climate-chemistry model (co-funded by Department of Energy). The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the AER two-dimensional chemistry-transport model, the AER two-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry
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