13,434 research outputs found

    Energy harvesting from vehicular traffic over speed bumps: A review

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    Energy used by vehicles to slow down in areas of limited speed is wasted. A traffic energy-harvesting device (TEHD) is capable of harvesting vehicle energy when passing over a speed bump. This paper presents a classification of the different technologies used in the existing TEHDs. Moreover, an estimation of the energy that could be harvested with the different technologies and their cost has been elaborated. The energy recovered with these devices could be used for marking and lighting of roads in urban areas, making transportation infrastructures more sustainable and environmentally friendly

    Headache features in people with whiplash associated disorders: A scoping review.

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    Whiplash-associated headache (WAH) is one of the most common symptoms after a whiplash injury, leading to high disability. Nevertheless, the clinical characteristics of WAH have not been well described. To synthesise the existing literature on the clinical characteristics of WAH. Scoping review. The protocol for this scoping review was registered in Open Science Framework and the PRISMA extension for Scoping Reviews tool was used to ensure methodological and reporting quality. A systematic search was conducted in PubMed, EMBASE, CINAHL, Web of Science and Scopus. The search was performed by one author and the screening of articles was conducted by two authors independently. A total of 11363 articles were initially identified and finally 26 studies were included in the review. Headache intensity was the most commonly reported feature. Headache duration, frequency and location were also reported in at least four studies. Few studies reported physical impairments that may be related to the presence of WAH. A differentiation with concussion characteristics was only performed in eight studies. WAH appears to be of mild to moderate intensity, typically with episodes of short duration which is commonly experienced in the occipital region amongst other regions, and with a tendency to reduce in intensity over time. [Abstract copyright: Copyright © 2023. Published by Elsevier Ltd.

    On supersymmetric Minkowski vacua in IIB orientifolds

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    Supersymmetric Minkowski vacua in IIB orientifold compactifications based on orbifolds with background fluxes and non-perturbative superpotentials are investigated. Especially, microscopic requirements and difficulties to obtain such vacua are discussed. We show that orbifold models with one and two complex structure moduli and supersymmetric 2-form flux can be successfully stabilized to such vacua. By taking additional gaugino condensation on fixed space-time filling D3-branes into account also models without complex structure can be consistently stabilized to Minkowski vacua.Comment: 17 pages, 2 figures; More detailed proof for absence of complex flat directions in susy AdS vacua given; Footnotes and reference adde

    Surface stress of Ni adlayers on W(110): the critical role of the surface atomic structure

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    Puzzling trends in surface stress were reported experimentally for Ni/W(110) as a function of Ni coverage. In order to explain this behavior, we have performed a density-functional-theory study of the surface stress and atomic structure of the pseudomorphic and of several different possible 1x7 configurations for this system. For the 1x7 phase, we predict a different, more regular atomic structure than previously proposed based on surface x-ray diffraction. At the same time, we reproduce the unexpected experimental change of surface stress between the pseudomorphic and 1x7 configuration along the crystallographic surface direction which does not undergo density changes. We show that the observed behavior in the surface stress is dominated by the effect of a change in Ni adsorption/coordination sites on the W(110) surface.Comment: 14 pages, 3 figures Published in J. Phys.: Condens. Matter 24 (2012) 13500

    Oscillation damping of chiral string loops

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    Chiral cosmic string loop tends to the stationary (vorton) configuration due to the energy loss into the gravitational and electromagnetic radiation. We describe the asymptotic behaviour of near stationary chiral loops and their fading to vortons. General limits on the gravitational and electromagnetic energy losses by near stationary chiral loops are found. For these loops we estimate the oscillation damping time. We present solvable examples of gravitational radiation energy loss by some chiral loop configurations. The analytical dependence of string energy with time is found in the case of the chiral ring with small amplitude radial oscillations.Comment: 10 pages, 2 figures. Accepted for publication in Physical Review

    Optical/Near-Infrared Observations of GRO J1744-28

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    We present results from a series of optical (g and r-band) and near-infrared (K'-band) observations of the region of the sky including the entire XTE and ROSAT error circles for the ``Bursting Pulsar'' GRO J1744-28. These data were taken with the Astrophysical Research Consortium's 3.5-m telescope at Apache Point Observatory and with the 2.2-m telescope at the European Southern Observatory. We see no new object, nor any significant brightening of any known object, in these error circles, with the exception of an object detected in our 8 February 1996 image. This object has already been proposed as a near-infrared counterpart to GRO J1744-28. While it is seen in only two of our ten 8 February frames, there is no evidence that this is an instrumental artifact, suggesting the possibility of near-infrared flares from GRO J1744-28, similar to those that have been reported from the Rapid Burster. The distance to the ``Bursting Pulsar'' must be more than 2 kpc, and we suggest that it is more than 7 kpc.Comment: 21 pages, 5 JPEG plates, 2 postscript figures. This paper will appear in the May 1, 1997 edition of the Astrophysical Journa

    Mapping powdery mildew (Blumeria graminis f. sp. tritici) resistance inwild and cultivated tetraploid wheats

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    Wheat is the most widely grown crop and represents the staple food for one third of the world’s population. Wheat is attacked by a large variety of pathogens and the use of resistant cultivars is an effective and environmentally safe strategy for controlling diseases and eliminating the use of fungicides. In this study, a collection of wild and cultivated tetraploid wheats (Triticum turgidum) were evaluated for seedling resistance (SR) and adult plant resistance (APR) to powdery mildew (Blumeria graminis) and genotyped with a 90K single nucleotide polymorphism (SNP) array to identify new sources of resistance genes. The genome-wide association mapping detected 18 quantitative trait loci (QTL) for APR and 8 QTL for SR, four of which were identical or at least closely linked to four QTL for APR. Thirteen candidate genes, containing nucleotide binding sites and leucine-rich repeats, were localized in the confidence intervals of the QTL-tagging SNPs. The marker IWB6155, associated to QPm.mgb-1AS, was located within the gene TRITD1Av1G004560 coding for a disease resistance protein. While most of the identified QTL were described previously, five QTL for APR (QPm.mgb-1AS, QPm.mgb-2BS, QPm.mgb-3BL.1, QPm.mgb-4BL, QPm.mgb-7BS.1) and three QTL for SR (QPm.mgb-3BL.3, QPm.mgb-5AL.2, QPm.mgb-7BS.2) were mapped on chromosome regions where no resistance gene was reported before. The novel QTL/genes can contribute to enriching the resistance sources available to breeders

    Chiral Superconducting Membranes

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    We develop the dynamics of the chiral superconducting membranes (with null current) in an alternative geometric approach either making a Lagrangian description and a Hamiltonian point of view. Besides of this, we show the equivalence of the resulting descriptions to the one known Dirac-Nambu-Goto (DNG) case. Integrability for chiral string model is obtained using a proposed light-cone gauge. In a similar way, domain walls are integrated by means of a simple ansatz. We compare the results with recently works appeared in the literature.Comment: Latex file, 17 pages, no figures. Improved version, typos corrected, Comments and references adde

    Tunneling mechanism of light transmission through metallic films

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    A mechanism of light transmission through metallic films is proposed, assisted by tunnelling between resonating buried dielectric inclusions. This is illustrated by arrays of Si spheres embedded in Ag. Strong transmission peaks are observed near the Mie resonances of the spheres. The interaction among various planes of spheres and interference effects between these resonances and the surface plasmons of Ag lead to mixing and splitting of the resonances. Transmission is proved to be limited only by absorption. For small spheres, the effective dielectric constant can be tuned to values close to unity and a method is proposed to turn the resulting materials invisible.Comment: 4 papges, 5 figure

    What is the best method for preserving the genuine black truffle (Tuber melanosporum) aroma? An olfactometric and sensory approach

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    The aim of this work was to evaluate the effects of different preservation methods (freeze-drying, hot-air drying, freezing and canning) on the aroma profile of T. melanosporum truffles. Volatile organic compounds (VOCs) were extracted by solid-phase microextraction (SPME) and analysed by gas-chromatography olfactometry to monitor changes occurring in key-aroma compounds. Samples were also submitted to descriptive sensory analysis by a panel of trained judges, with the aim of correlating both sets of data. Freeze-drying - and to a lesser extent hot-air drying - were the only treatments able to retain key-compounds such as dimethylsulphide (DMS) and dimethyldisulphide (DMDS), evoking the aroma typically associated with fresh truffle. Principal component analysis (PCA) performed on the descriptive data showed the sensorial proximity between fresh and freeze-dried truffle, and also the differences between them and those frozen and canned. Despite some differences in the odour volatile profile of fresh and freezed-dried truffles (mainly the lack of 2, 3-butanedione and branched ethyl esters), freeze-drying is the most suitable technique for preserving the overall original aroma of fresh truffle. Several key-odour compounds - mainly unsaturated linear chain carbonyl compounds, sulphur and pyrrole derivates - emerge as biomarkers of the studied technologies
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