1,310 research outputs found

    High-fidelity simulations of CdTe vapor deposition from a new bond-order potential-based molecular dynamics method

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    CdTe has been a special semiconductor for constructing the lowest-cost solar cells and the CdTe-based Cd1-xZnxTe alloy has been the leading semiconductor for radiation detection applications. The performance currently achieved for the materials, however, is still far below the theoretical expectations. This is because the property-limiting nanoscale defects that are easily formed during the growth of CdTe crystals are difficult to explore in experiments. Here we demonstrate the capability of a bond order potential-based molecular dynamics method for predicting the crystalline growth of CdTe films during vapor deposition simulations. Such a method may begin to enable defects generated during vapor deposition of CdTe crystals to be accurately explored

    Self-aligned nanoscale SQUID on a tip

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    A nanometer-sized superconducting quantum interference device (nanoSQUID) is fabricated on the apex of a sharp quartz tip and integrated into a scanning SQUID microscope. A simple self-aligned fabrication method results in nanoSQUIDs with diameters down to 100 nm with no lithographic processing. An aluminum nanoSQUID with an effective area of 0.034 ÎŒ\mum2^2 displays flux sensitivity of 1.8⋅10−6\cdot 10^{-6} Ί0/Hz1/2andoperatesinfieldsashighas0.6T.Withprojectedspinsensitivityof65\Phi_0/\mathrm{Hz}^{1/2} and operates in fields as high as 0.6 T. With projected spin sensitivity of 65 \mu_B/\mathrm{Hz}^{1/2}$ and high bandwidth, the SQUID on a tip is a highly promising probe for nanoscale magnetic imaging and spectroscopy.Comment: 14 manuscript pages, 5 figure

    SigurĂ°ar saga fĂłts (The Saga of SigurĂ°r Foot): A Translation

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    This is the first English translation of the short Icelandic romance SigurĂ°ar saga fĂłts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, SigurĂ°ar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (SignĂœ): the eponymous SigurĂ°r fĂłtr wins SignĂœ only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

    SigurĂ°ar saga fĂłts (The Saga of SigurĂ°r Foot): A Translation

    Get PDF
    This is the first English translation of the short Icelandic romance SigurĂ°ar saga fĂłts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, SigurĂ°ar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (SignĂœ): the eponymous SigurĂ°r fĂłtr wins SignĂœ only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

    Persistent and Coupling Current Effects in the LHC Superconducting Dipoles

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    One of the main issues for the operation of the LHC accelerator at CERN is the field errors generated by persistent and coupling currents in the main dipoles at injection conditions, i.e., 0.54 T dipole field. For this reason we are conducting systematic magnetic field measurements to quantify the above effects and compare them to the expected values from measurement on strands and cables. We discuss the results in terms of DC effects from persistent current magnetization, AC effects with short time constant from strand and cable coupling currents, and long-term decay during constant current excitation. Average and spread of the measured field errors over the population of magnets tested are as expected or smaller. Field decay at injection, and subsequent snap-back, show for the moment the largest variation from magnet to magnet, with weak correlation to parameters that can be controlled during production. For this reason these effects are likely to result in the largest spread of field errors over the whole dipole production

    Sensitivity Studies for Third-Generation Gravitational Wave Observatories

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    Advanced gravitational wave detectors, currently under construction, are expected to directly observe gravitational wave signals of astrophysical origin. The Einstein Telescope, a third-generation gravitational wave detector, has been proposed in order to fully open up the emerging field of gravitational wave astronomy. In this article we describe sensitivity models for the Einstein Telescope and investigate potential limits imposed by fundamental noise sources. A special focus is set on evaluating the frequency band below 10Hz where a complex mixture of seismic, gravity gradient, suspension thermal and radiation pressure noise dominates. We develop the most accurate sensitivity model, referred to as ET-D, for a third-generation detector so far, including the most relevant fundamental noise contributions.Comment: 13 pages, 7 picture

    Comparative Immunohistochemical Study of Multicystic Dysplastic Kidneys With and Without Obstruction

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    Etiology of multicystic dysplastic kidney (MCDK) remains unknown. Not all cases are associated with obstruction. We compared by immunohistochemistry 17 cases of MCDK (10 cases with and seven without obstruction) to 17 controls and 20 fetal kidneys. TGF-ÎČ was negative in obstructive MCDKs and positive in nonobstructive MCDK. IGF2 was overexpressed in obstructive and underex-pressed in nonobstructive MCDKs. PAX2, BCL-2, and ÎČ-catenin were expressed equally in obstructive and nonobstructive dysplasia. TGF-ÎČ and IGF2 work by different mechanisms in obstructive and nonobstructive MCDKs, but there are no differences among PAX 2, BCL-2, and ÎČ-catenin in obstructive versus nonobstructive dysplasia

    Bringing sensation to prosthetic hands—chronic assessment of implanted thin-film electrodes in humans

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    Direct stimulation of peripheral nerves with implantable electrodes successfully provided sensory feedback to amputees while using hand prostheses. Longevity of the electrodes is key to success, which we have improved for the polyimide-based transverse intrafascicular multichannel electrode (TIME). The TIMEs were implanted in the median and ulnar nerves of three trans-radial amputees for up to six months. We present a comprehensive assessment of the electrical properties of the thin-film metallization as well as material status post explantationem. The TIMEs stayed within the electrochemical safe limits while enabling consistent and precise amplitude modulation. This lead to a reliable performance in terms of eliciting sensation. No signs of corrosion or morphological change to the thin-film metallization of the probes was observed by means of electrochemical and optical analysis. The presented longevity demonstrates that thin-film electrodes are applicable in permanent implant systems

    Scientific Potential of Einstein Telescope

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    Einstein gravitational-wave Telescope (ET) is a design study funded by the European Commission to explore the technological challenges of and scientific benefits from building a third generation gravitational wave detector. The three-year study, which concluded earlier this year, has formulated the conceptual design of an observatory that can support the implementation of new technology for the next two to three decades. The goal of this talk is to introduce the audience to the overall aims and objectives of the project and to enumerate ET's potential to influence our understanding of fundamental physics, astrophysics and cosmology.Comment: Conforms to conference proceedings, several author names correcte
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