1,347 research outputs found

    Preparation of heterocyclic block copolymer from perfluoroalkylene oxide alpha, omega-diamidoximes

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    Diamidoxime monomers are intermolecularly and thermally condensed to form a heat and chemical resistant polymer containing 1,2,4-oxadiazole linkages with identical bivalent organic radicals or any combination of bivalent organic radicals selected from the group consisting of -(CX(sub 2))p-, wherein P ranges from 2 to 8 when X is fluorine and 2 to 18 when X is hydrogen, chlorine, nitro or aryl; arylene; and an oligometric or polymeric radical prepared by reacting a dicarboxylic acid halide with a fluorinated epoxide and having the formula: (CFY(OCF(sub 2)CFY)sub m)O(CX(sub 2))(sub p)O(CFYCF(sub 2)O)(sub n)CFY wherein Y is flourine or tryifluoromethyl, X is nitro, aryl, hydrogen, chlorine or fluorine, preferably the latter, p ranges from 1 to 18 and m+n ranges from 2 to 7

    Dynamic Change Evaluation for Ontology Evolution in the Semantic Web

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    Changes in an ontology may have a disruptive impact on any system using it. This impact may depend on structural changes such as introduction or removal of concept definitions, or it may be related to a change in the expected performance of the reasoning tasks. As the number of systems using ontologies is expected to increase, and given the open nature of the Semantic Web, introduction of new ontologies and modifications to existing ones are to be expected. Dynamically handling such changes, without requiring human intervention, becomes crucial. This paper presents a framework that isolates groups of related axioms in an OWL ontology, so that a change in one or more axioms can be automatically localised to a part of the ontology

    Green synthesis of gold nanoparticles using Kiwifruit juice

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    The use of kiwifruit juice as a source of metal-reducing and stabilizing agents for the production of gold nanoparticles (AuNPs) was investigated. The reaction was carried out in batch by mixing appropriate amounts of kiwifruit juice and gold(III) chloride solution. The formation of AuNPs was monitored by measuring the intensity of the surface plasmon resonance (SPR) band of gold. The effects of temperature (20-60 °C), pH (8-12) and gold-to-polyphenol ratio (GPR) were investigated. Characterisation of AuNPs by XRD, DLS and zeta-potential measurements showed that they were highly crystalline, with an average hydrodynamic diameter of about 50 nm and a zeta-potential ranging between -29.2 and -21.7 mV. Under the best reaction conditions (60 °C, pH 9, GPR = 5 mol Au3+/mol GAE), AuNPs with an average size of about 30 nm were produced. The results obtained suggest that kiwifruit juice is a suitable medium for the production of small-sized and stable AuNPs

    Shape-changing Collisions of Coupled Bright Solitons in Birefringent Optical Fibers

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    Wecritically review the recent progress in understanding soliton propagation in birefringent optical fibers.By constructing the most general bright two-soliton solution of the integrable coupled nonlinear Schroedinger equation (Manakov model) we point out that solitons in birefringent fibers can in general change their shape after interaction due to a change in the intensity distribution among the modes even though the total energy is conserved. However, the standard shape-preserving collision (elastic collision) property of the (1+1)-dimensional solitons is recovered when restrictions are imposed on some of the soliton parameters. As a consequence the following further properties can be deduced using this shape-changing collision. (i) The exciting possibility of switching of solitons between orthogonally polarized modes of the birefringent fiber exists. (ii) When additional effects due to periodic rotation of birefringence axes are considered, the shape changing collision can be used as a switch to suppress or to enhance the periodic intensity exchange between the orthogonally polarized modes. (iii) For ultra short optical soliton pulse propagation in non-Kerr media, from the governing equation an integrable system of coupled nonlinear Schroedinger equation with cubic-quintic terms is identified. It admits a nonlocal Poisson bracket structure. (iv) If we take the higher-order terms in the coupled nonlinear Schroedinger equation into account then their effect on the shape-changing collision of solitons, during optical pulse propagation, can be studied by using a direct perturbational approach.Comment: 14 pages, ROMP31, 4 EPS figure

    Integrating MRP in production systems simulation tools

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    Literature review suggests concentrating on the development of new reference model for manufacturing system simulation, which may implement an operation logic much closer to real industrial contexts. A production system modelling tool should be designed with the aim of standardizing and simplifying the simulation of manufacturing processes and to widespread this approach in SMEs. With this aim, the authors got committed in designing a reference model for providing a structural framework to support shop-floor simulation and optimization. This paper presents the basic framework logic and structure of the simulation tool, showing how it is possible to represent it in Business Process Modelling Notation (BPMN). On top of this, the efforts of implementing an MRP module on top of a simulation took which was originally conceived to embed look-back material handling policies area described, together with the operative solutions chosen to reach the integration

    Evaluation of flow dependent external costs in freight logistics networks

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    In this paper we face a distribution problem arising in a freight logistics context. More precisely, we are involved with the containerized flow originating from maritime terminals and going to inland destinations using the road transportation network. The goal is the minimization of the total shipping costs, given by the travelled distance, vehicles and external cost components. In particular, we consider accidental and polluting costs as external negative costs. Note that the proposed externality costs depend on the amount of flow through the selected arcs in the route and their capacity; therefore, a novel stepwise function is proposed and analyzed. A deep analysis is performed for evaluating the impact of environmental externalities on the choice of the route in terms of costs and distances depending on the density of the traffic. Results of an extensive computational experimentation performed with randomly generated instances of different size and capacity values of the arcs are reported. A real case instance related to the logistics network connecting the main ports of the Liguria County (Italy) to the main inland destinations is finally proposed and analyzed

    Agreement Between Older Persons and Their Surrogate Decision‐Makers Regarding Participation in Advance Care Planning

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    Objectives: To examine agreement between older persons and their surrogates regarding participation in advance care planning (ACP). Design: Observational cohort study. Setting: Community. Participants: Persons aged 65 and older and the individual they identified as most likely to make treatment decisions on their behalf. Measurements: Older persons were asked about participation in four activities: completion of living will, completion of healthcare proxy, communication regarding views about life‐sustaining treatment, and communication regarding views about quality versus quantity of life. Surrogates were asked whether they believed the older person had completed these activities. Results: Of 216 pairs, 81% agreed about whether a living will had been completed (κ=0.61, 95% confidence interval (CI) 0.51–0.72). Only 68% of pairs agreed about whether a healthcare proxy had been completed (κ=0.39, 95% CI 0.29–0.50), 64% agreed about whether they had communicated regarding life‐sustaining treatment (κ=0.22, 95% CI 0.09–0.35), and 62% agreed about whether they had communicated regarding quality versus quantity of life (κ=0.23, 95% CI 0.11–0.35). Conclusion: Although agreement between older persons and their surrogates regarding living will completion was good, agreement about participation in other aspects of ACP was fair to poor. Additional study is necessary to determine who is providing the most accurate report of objective ACP components and whether agreement regarding participation in ACP is associated with greater shared understanding of patient preferences

    Searching for galactic axions through magnetized media: QUAX status report

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    The current status of the QUAX R\&D program is presented. QUAX is a feasibility study for a detection of axion as dark matter based on the coupling to the electrons. The relevant signal is a magnetization change of a magnetic material placed inside a resonant microwave cavity and polarized with a static magnetic field.Comment: Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs, Thessaloniki, May 15 to 19, 201

    Feasibility of Delivering a Tailored Intervention for Advance Care Planning in Primary Care Practice

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    Background/Objectives: To determine the feasibility of conducting a cluster randomized controlled trial providing individualized feedback reports to increase advance care planning (ACP) engagement in the primary care setting. Design: Pilot cluster randomized controlled trial. Setting: Two primary care practices selected for geographic colocation. Participants: Adults aged 55 years and older. Intervention: Brief assessment of readiness to engage in (stage of change for) three ACP behaviors (healthcare agent assignment, communication with agent about quality vs quantity of life, and living will completion) generating an individualized feedback report, plus a stage-matched brochure. Measures: Patient recruitment and retention, intervention delivery, baseline characteristics, and stage of change movement. Results: Recruitment rates differed by practice. Several baseline sociodemographic characteristics differed between the 38 intervention and 41 control participants, including employment status, education, and communication with healthcare agent. Feedback was successfully delivered to all intervention participants, and over 90% of participants completed a 2-month follow-up. More intervention participants demonstrated progression in readiness than did control participants, without testing for statistical significance. Conclusions: This pilot demonstrates opportunities and challenges of performing a clustered randomized controlled trial in primary care practices. Differences in the two practice populations highlight the challenges of matching sites. There was a signal for behavior change in the intervention group

    Axion search with a quantum-limited ferromagnetic haloscope

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    A ferromagnetic axion haloscope searches for Dark Matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter YIG spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin-magnetometer ever realized. The minimum detectable field is 5.5×10195.5\times10^{-19}\,T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant gaee1.7×1011g_{aee}\le1.7\times10^{-11} at 95% CL. The scientific run of our haloscope resulted in the best limit on DM-axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion mass range 42.442.4-43.1μ43.1\,\mueV. This is also the first apparatus to perform an axion mass scanning by changing the static magnetic field.Comment: 4 pages, 4 figure
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