3,006 research outputs found

    HotMobile 2008: Postconference Report

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    HotMobile 2008 presented a two-day program on mobile computing systems and applications. The authors focuses on the sessions on sensors, modularity, wireless, security, systems, and screens. The mobile device is the most amazing invention in history and that it has had the largest impact on human kind. Because mobile phones combine mobile devices with ongoing developments in software and communication technologies, they have the potential to change the way people think and act

    Revision of empirical electric field modeling in the inner magnetosphere using Cluster data

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    Using Cluster data from the Electron Drift (EDI) and the Electric Field and Wave (EFW) instruments, we revise our empirically-based, inner-magnetospheric electric field (UNH-IMEF) model at 22.662 mV/m; K-p\u3c1, 1K(p)\u3c2, 2K(p)\u3c3, 3K(p)\u3c4, 4K(p)\u3c5, and K(p)4(+). Patterns consist of one set of data and processing for smaller activities, and another for higher activities. As activity increases, the skewed potential contour related to the partial ring current appears on the nightside. With the revised analysis, we find that the skewed potential contours get clearer and potential contours get denser on the nightside and morningside. Since the fluctuating components are not negligible, standard deviations from the modeled values are included in the model. In this study, we perform validation of the derived model more extensively. We find experimentally that the skewed contours are located close to the last closed equipotential, consistent with previous theories. This gives physical context to our model and serves as one validation effort. As another validation effort, the derived results are compared with other models/measurements. From these comparisons, we conclude that our model has some clear advantages over the others

    ALMA view of the circumstellar environment of the post-common-envelope-evolution binary system HD101584

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    We study the circumstellar evolution of the binary HD101584, consisting of a post-AGB star and a low-mass companion, which is most likely a post-common-envelope-evolution system. We used ALMA observations of the 12CO, 13CO, and C18O J=2-1 lines and the 1.3mm continuum to determine the morphology, kinematics, masses, and energetics of the circumstellar environment. The circumstellar medium has a bipolar hour-glass structure, seen almost pole-on, formed by an energetic jet, about 150 km/s. We conjecture that the circumstellar morphology is related to an event that took place about 500 year ago, possibly a capture event where the companion spiraled in towards the AGB star. However, the kinetic energy of the accelerated gas exceeds the released orbital energy, and, taking into account the expected energy transfer efficiency of the process, the observed phenomenon does not match current common-envelope scenarios. This suggests that another process must augment, or even dominate, the ejection process. A significant amount of material resides in an unresolved region, presumably in the equatorial plane of the binary system.Comment: A&A Letter, accepte

    First detection of methanol towards a post-AGB object, HD101584

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    The circumstellar environments of objects on the asymptotic giant branch and beyond are rich in molecular species. Nevertheless, methanol has never been detected in such an object, and is therefore often taken as a clear signpost for a young stellar object. However, we report the first detection of CH3OH in a post-AGB object, HD101584, using ALMA. Its emission, together with emissions from CO, SiO, SO, CS, and H2CO, comes from two extreme velocity spots on either side of the object where a high-velocity outflow appears to interact with the surrounding medium. We have derived molecular abundances, and propose that the detected molecular species are the effect of a post-shock chemistry where circumstellar grains play a role. We further provide evidence that HD101584 was a low-mass, M-type AGB star

    The Photovoltaic Crisis and the Demand-side Generation in Spain

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    The RES-E promotion policy in Spain gave priority to the photovoltaic (henceforth, PV) ground-mounted installations. For years, the coupling of customer-side generation coupled with excess energy exports was never specifically considered. However, some months ago this option was suggested as a way to recover the Spain��s PV sector from the current moratorium on the RES-E policy. A decree draft on on-site generation was issued, its central point being the consideration of electricity exports as delayed consumption rights. But several barriers hinder its entry into force. Unfortunately, Spain could be losing an important opportunity for encouraging PV investments while retail grid parity is being reached. This working paper analyzes the different types of PV demand-side generation from the point of view of consumer-generators and evaluates the economic and technical features of the regulation proposed in Spain and to date still pending

    Cold streams of ionospheric oxygen in the plasma sheet during the CDAW-6 event of March 22, 1979

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    During magnetospheric substorm events, the plasma and ion composition experiments in the ISEE-1 and 2 satellites detected cold ionospheric O+ streams, moving tailwards in the near Earth magnetotail. Flow is parallel to the magnetic field lines, with drift velocity in agreement with the electric field topology obtained by mapping the model ionospheric field along the magnetic field lines. Fluctuations of the flow velocity of the streams can be related to magnetotail movements. Oscillations of the flow direction and speed with periods ranging from 5 to 10 min that suggest the presence of waves are observed. The streams are observed at all distances between 15 and 6 Re from the Earth. When averaged over 360 deg, the streams show up as a low energy peak, superimposed on the distribution of isotropic plasma sheet ions. This double-peak structure of the energy spectrum seems typical of the disturbed plasma sheet

    Dissection Technique for Cochleas Prepared for Scanning Electron Microscopy

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    Scanning electron microscopy (SEM) permits a three-dimensional study of the surface morphology of the organ of Corti that is very useful in evaluating the condition of the apical end of the hair cells and the stereocilia. However, some laboratories have experienced problems with curling of the basilar membrane during critical point drying of cochlear specimens prepared For SEM evaluation using the Murakami or osmium thiocarbohydrazide-procedures. This curling of the basilar membrane can obstruct the view of the reticular lamina and the ciliary ends of the hair cells. We have used a dissection method, referred to as the anchor technique, to overcome basilar membrane curling. This technique removes all the structures above the reticular lamina but leaves the basilar membrane attached to the spiral ligament and the lateral bone to which the spiral ligament is anchored. Individual cochlear turns are dissected in this manner and mounted on the same examination stub For SEM evaluation. Maintenance of the lateral attachment of the basilar membrane requires additional dissection time but eliminates the problem of curling during critical point drying. An additional benefit is that mounting the individual turns on the same examination stub Facilitates evaluation and photomicroscopy of the surface morphology. The anchor technique has been used successfully on the guinea pig and should be appropriate for most mammalian cochleas

    Quantitative Evaluation of Scanning Electron Microscopy-Examined Ciliary Morphological Changes in Control and Noise Exposed Guinea Pig Cochleas

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    Many investigations of noise-induced hearing loss have demonstrated a poor correlation between hearing threshold and hair cell loss. One reason for this is that more subtle changes in the hair cell, such as detailed morphological changes of stereocilia, have not been evaluated. However, examining such changes increases the problem of distinguishing experimental pathological changes from artefacts. Preparation of the specimen for scanning electron microscopy (SEM) may result in too many artefacts for an adequate quantification of defects due to noise exposure. One problem with some earlier studies seems to be lack of controls and/or statistical analysis for the purpose of eliminating the influence of artefacts and spontaneous degeneration. The aim of this study was to compare unexposed and noise-exposed cochleas examined with SEM in order to determine if subtle changes due to noise could be distinguished from preparation artefacts and from spontaneous deterioration. Ten different types of hair cell changes were found in exposed and control animals. By means of using controls for statistical comparison with noise-exposed animals two cell damage categories hair cell loss and missing stereocilia were found to be produced by exposure to noise

    Vitaminer og fedtsyrer i hø og ensilage – hvad sker der vid forvejring og lagring?

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    For at undersøge stabiliteten af vitaminer i moderne ensilage- og høproduktion, har FØJO III projektet ECOVIT, igennem to vækstår, målt vitaminindholdet i forskellige græsmarksafgrøder ved forskellige høsttidspunkter og sletintervaller. Resultaterne viser, at det største tab af vitaminer og umættede fedtsyrer sker i forbindelse med forvejringen, mens tabet i lagringsperioden er begrænset
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