177 research outputs found

    Electrochemical intercalation and electrical conductivity of graphite fibers

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    Lamellar compounds of graphite fibers were prepared by electrochemical intercalation. The dependence of the electrical resistance on the intercalate concentration was determined by a quasi simultaneous method. A factor 30 decrease of the relative fiber resistance was obtained with fluorosulfuric acid

    Consistent Inversion of Noisy Non-Abelian X-Ray Transforms

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    For MM a simple surface, the non-linear statistical inverse problem of recovering a matrix field Φ:M→so(n)\Phi: M \to \mathfrak{so}(n) from discrete, noisy measurements of the SO(n)SO(n)-valued scattering data CΦC_\Phi of a solution of a matrix ODE is considered (n≥2n\geq 2). Injectivity of the map Φ↦CΦ\Phi \mapsto C_\Phi was established by [Paternain, Salo, Uhlmann; Geom.Funct.Anal. 2012]. A statistical algorithm for the solution of this inverse problem based on Gaussian process priors is proposed, and it is shown how it can be implemented by infinite-dimensional MCMC methods. It is further shown that as the number NN of measurements of point-evaluations of CΦC_\Phi increases, the statistical error in the recovery of Φ\Phi converges to zero in L2(M)L^2(M)-distance at a rate that is algebraic in 1/N1/N, and approaches 1/N1/\sqrt N for smooth matrix fields Φ\Phi. The proof relies, among other things, on a new stability estimate for the inverse map CΦ→ΦC_\Phi \to \Phi. Key applications of our results are discussed in the case n=3n=3 to polarimetric neutron tomography, see [Desai et al., Nature Sc.Rep. 2018] and [Hilger et al., Nature Comm. 2018

    Ti3SiC2-formation during Ti–C–Si multilayer deposition by magnetron sputtering at 650 °C

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    Titanium Silicon Carbide films were deposited from three separate magnetrons with elemental targets onto Si wafer substrates. The substrate was moved in a circular motion such that the substrate faces each magnetron in turn and only one atomic species (Ti, Si or C) is deposited at a time. This allows layer-by-layer film deposition. Material average composition was determined to Ti0.47Si0.14C0.39 by energy-dispersive X-ray spectroscopy. High-resolution transmission electron microscopy and Raman spectroscopy were used to gain insights into thin film atomic structure arrangements. Using this new deposition technique formation of Ti3SiC2 MAX phase was obtained at a deposition temperature of 650 °C, while at lower temperatures only silicides and carbides are formed. Significant sharpening of Raman E2g and Ag peaks associated with Ti3SiC2 formation was observed

    The Impact of the Physical Environment on Intrapartum Maternity Care: Identification of Eight Crucial Building Spaces.

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    OBJECTIVES, PURPOSE, OR AIM: This article investigates whether the physical environment in which childbirth occurs impacts the intrapartum intervention rates and how this might happen. The study explores the spatial physical characteristics that can support the design of spaces to promote the health and well-being of women, their supporters, and maternity care professionals. BACKGROUND: Medical interventions during childbirth have consequences for the health of women and babies in the immediate and long term. The increase in interventions is multifactorial and may be influenced by the model of care adopted, the relationships between caregivers and the organizational culture, which is made up of many factors, including the built environment. In the field of birth architecture research, there is a gap in the description of the physical characteristics of birth environments that impact users' health. METHOD: A scoping review on the topic was performed to understand the direct and indirect impacts of the physical environment on birth intervention rates. RESULTS AND DISCUSSION: The findings are organized into three tables reporting the influence that the physical characteristics of a space might have on people's behaviors, experiences, practices and birth health outcomes. Eight building spaces that require further investigation and research were highlighted: unit layout configuration, midwives' hub/desk, social room, birth philosophy vectors, configuration of the birth room, size and shape of the birth room, filter, and sensory elements. CONCLUSIONS: The findings show the importance of considering the physical environment in maternity care and that further interdisciplinary studies focused on architectural design are needed to enrich the knowledge and evidence on this topic and to develop accurate recommendations for designers

    On strong causal binomial approximation for stochastic processes

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    This paper considers binomial approximation of continuous time stochastic processes. It is shown that, under some mild integrability conditions, a process can be approximated in mean square sense and in other strong metrics by binomial processes, i.e., by processes with fixed size binary increments at sampling points. Moreover, this approximation can be causal, i.e., at every time it requires only past historical values of the underlying process. In addition, possibility of approximation of solutions of stochastic differential equations by solutions of ordinary equations with binary noise is established. Some consequences for the financial modelling and options pricing models are discussed

    The Many Virtues of Second Nature : Habitus in Latin Medieval Philosophy

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    This chapter consists of a systematic introduction to the nature and function of habitus in Latin medieval philosophy. Over the course of this introduction, several topics are treated: the theoretical necessity to posit habitus; their nature; their causal contribution to the production of internal and external acts; how and why habitus can grow and decay; what makes their unity when they can have multiple objects and work in clusters. Finally we examine two specific questions: why intellectual habitus represent a special case that triggered considerable debate; how human beings can be said to be free if their actions are determined by moral habitus
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