1,218 research outputs found

    Observation of the Faraday effect via beam deflection in a longitudinal magnetic field

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    We report the observation of the magnetic field induced circular differential deflection of light at the interface of a Faraday medium. The difference in the angles of refraction or reflection between the two circular polarization components is a function of the magnetic field strength and the Verdet constant. The reported phenomena permit the observation of the Faraday effect not via polarization rotation in transmission, but via changes in the propagation direction in refraction or in reflection. An unpolarized light beam is predicted to split into its two circular polarization components. The light deflection arises within a few wavelengths at the interface and is therefore independent of pathlength

    The application of inelastic neutron scattering to investigate the interaction of methyl propanoate with silica

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    A modern industrial route for the manufacture of methyl methacrylate involves the reaction of methyl propanoate and formaldehyde over a silica-supported Cs catalyst. Although the process has been successfully commercialised, little is known about the surface interactions responsible for the forward chemistry. This work concentrates upon the interaction of methyl propanoate over a representative silica. A combination of infrared spectroscopy, inelastic neutron scattering, DFT calculations, X-ray diffraction and temperature-programmed desorption is used to deduce how the ester interacts with the silica surface

    Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene

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    The interaction of CO with an attapulgite-supported Cu(II)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment where the supported Cu(II)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at ~ 370°C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of x-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption

    On robots with reasoning capabilities and human-like appearance and behaviour: implications for accident investigations

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    AI-enhanced reasoning enables robots to create detailed accounts of their own situated behaviour as well as the behaviour of other people. This capability is currently employed by robot designers to achieve transparency, trust, and enhance robot social and communicative capabilities. Furthermore, robots may be designed to resemble humans both in their physical appearance and their behaviour. This approach is intended to facilitate more effective interactions with people. In this article we identify and examine some of the ethical, social and legal implications of these capabilities for the investigation of robot accidents. We consider two aspects in particular. The first of these is the role of robots as subjects in a testimony regarding an incident in which they are directly or indirectly involved. This can be described as a case of robots acting as witnesses. The second aspect is the role of robots as objects in a human testimony. This can be described as a case of robots being witnessed

    Digital mammography, cancer screening: Factors important for image compression

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    The use of digital mammography for breast cancer screening poses several novel problems such as development of digital sensors, computer assisted diagnosis (CAD) methods for image noise suppression, enhancement, and pattern recognition, compression algorithms for image storage, transmission, and remote diagnosis. X-ray digital mammography using novel direct digital detection schemes or film digitizers results in large data sets and, therefore, image compression methods will play a significant role in the image processing and analysis by CAD techniques. In view of the extensive compression required, the relative merit of 'virtually lossless' versus lossy methods should be determined. A brief overview is presented here of the developments of digital sensors, CAD, and compression methods currently proposed and tested for mammography. The objective of the NCI/NASA Working Group on Digital Mammography is to stimulate the interest of the image processing and compression scientific community for this medical application and identify possible dual use technologies within the NASA centers

    A Neural-Endocrine Architecture for Foraging in Swarm Robotic Systems

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    Abstract This paper presents the novel use of the Neural-endocrine architecture for swarm robotic systems. We make use of a number of behaviours to give rise to emergent swarm behaviour to allow a swarm of robots to collaborate in the task of foraging. Results show that the architecture is amenable to such a task, with the swarm being able to successfully complete the required task.

    A simulated real-world upper-body exoskeleton accident and investigation

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    This paper describes the enactment of a simulated (mock) accident involving an upper-body exoskeleton and its investigation. The accident scenario is enacted by role-playing volunteers, one of whom is wearing the exoskeleton. Following the mock accident, investigators – also volunteers – interview both the subject of the accident and relevant witnesses. The investigators then consider the witness testimony alongside robot data logged by the ethical black box, in order to address the three key questions: what happened?, why did it happen?, and how can we make changes to prevent the accident happening again? This simulated accident scenario is one of a series we have run as part of the RoboTIPS project, with the overall aim of developing and testing both processes and technologies to support social robot accident investigation

    Non-localities in nucleon-nucleus potentials

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    Two causes of non-locality inherent in nucleon-nucleus scattering are considered. They are the results of two-nucleon antisymmetry of the projectile with each nucleon in the nucleus and the dynamic polarization potential representation of channel coupling. For energies ∼40−300\sim 40 - 300 MeV, a g-folding model of the optical potential is used to show the influence of the knock-out process that is a result of the two-nucleon antisymmetry. To explore the dynamic polarization potential caused by channel coupling, a multichannel algebraic scattering model has been used for low-energy scattering.Comment: 12 pages, 11 figures, submitted to EPJ

    A Review of Innovations in Disbonding Techniques for Repair and Recycling of Automotive Vehicles

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    The recycling, recovery and reuse of End-of-Life Vehicles (ELVs) has raised worldwide concerns. This paper identified drivers for new joining solutions in the automotive industry and specifically reviewed current use of adhesive technology. From an ELV recycling point of view, rapid assembly and disassembly joining solutions were identified as key technology drivers. Innovations in adhesive disbonding technologies were reviewed and suggestions for the most promising future disbonding technologies have been proposed

    Source placement error for permanent implant of the prostate

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134896/1/mp8058.pd
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