1,451 research outputs found

    Polymer multimode waveguide optical and electronic PCB manufacturing

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    The paper describes the research in the £1.3 million IeMRC Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB) Flagship Project in which 8 companies and 3 universities carry out collaborative research and which was formed and is technically led by the author. The consortium’s research is aimed at investigating a range of fabrication techniques, some established and some novel, for fabricating polymer multimode waveguides from several polymers, some formulations of which are being developed within the project. The challenge is to develop low cost waveguide manufacturing techniques compatible with commercial PCB manufacturing and to reduce their alignment cost. The project aims to take the first steps in making this hybrid optical waveguide and electrical copper track printed circuit board disruptive technology widely available by establishing and incorporating waveguide design rules into commercial PCB layout software and transferring the technology for fabricating such boards to a commercial PCB manufacturer. To focus the research the project is designing an optical waveguide backplane to tight realistic constraints, using commercial layout software with the new optical design rules, for a demonstrator into which 4 daughter cards are plugged, each carrying an aggregate of 80 Gb/s data so that each waveguide carries 10 Gb/s

    The Chance and Probability Concepts Project

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    This article, created by D.R. Green, describes an investigation of what concepts and intuitions concerning random processes are present in the minds of children of varying abilities across the 11-16 age range. The ability to list permutations, combinations and arrangements is also being investigated. The author states, "Over the past two decades the topic of 'Probabilityâ has been brought into the mathematics curriculum but it may be that this is more an empty gesture rather than a sound strategy." This article can help to alleviate many of the struggles in teaching probability concepts. The article is pitched at a more elementary audience, but is still a perfect resource for almost anyone teaching in the field

    Achieving 10 ps coincidence time resolution in TOF-PET is an impossible dream

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    Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.RST/Radiation, Science and TechnologyRST/Medical Physics & Technolog

    Shubnikov–de Haas oscillations of two-dimensional electron gas in an InAsN/InGaAs single quantum well

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    We present the first investigation of Shubnikov–de Haas (SdH) oscillations of two-dimensional electron gas formed in an InAsN/InGaAs single quantum well (QW) grown on an InP substrate using gas source molecular beam epitaxy and a radio-frequency (rf ) plasma nitrogen source. The photoluminescence (PL) peak energy of the InAsN/InGaAs QW decreases compared with that of InAs/InGaAs QW. This agrees with the bowing effect due to the incorporation of nitrogen atoms. The nitrogen content can be estimated to be 0.4% using the PL peak positions as well as x-ray diffraction. From the SdH oscillations, the carrier concentration is 2.85 × 1011 cm−2 and the effective mass is 0.1±0.01m0. The enhancement of the effective mass is mainly due to the incorporation of the nitrogen atoms in the InAs lattice, which is consistent with a recent study on InAsN bulk alloys. The large increase of the effective mass cannot be explained by the simple band anticrossing model. In addition, we observe a temperatureindependent magnetoresistivity at a critical magnetic field. Our analysis supports the fact that the value of the critical exponent in the quantum Hall effect is not universal

    Bepalen van het massatraagheidsmoment met behulp van een bifilar pendulum: Determining the moments of inertia using a bifilar pendulum

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    The aim of this thesis is to investigate the use of a bifilar pendulum for determining the moments of inertia of the TU Delft solar boat and to quantitatively predict the estimates. In the first part, several methods are discussed which can be applied in deriving the equations of motion of the pendulum. A new method, Kane's method, will be introduced. In the second part, this method will be used to derive the actual equations of motion. These equations are linearized around of the the pendulum's stationary positions to obtain expressions which link the moment of inertia about an axis to the period of oscillation of the pendulum about that axis. These equations are subsequently applied to the solar boat to derive estimates for the moments of inertia about the principle axis of the boat. The results of this thesis considers three different configurations of the bifilar pendulum with the solar boat suspended. One of these configurations results in the most accurate estimates for the moments of inertia, however, these have not been quantitatively predicted. The author suggests a modification in the definition of the bifilar pendulum such that this might be possible.Electrical Engineering, Mathematics and Computer ScienceNumerical analysi

    An introduction to management science: quantitative approaches to decision making

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    Retaining the accessible application-driven approach for which An Introduction to Management Science is highly regarded, adapting author Mik Wisniewski has carefully reworked the existing US textbook to benefit students across the UK, Europe, Middle East and Africa. Packed with diverse realistic examples from Scotland to Saudi Arabia, the landmark text from the ASW team is now available in a truly internationalised version for students studying Management Science and Operations Research at postgraduate and undergraduate level

    Immunotherapy

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    A chapter covering metastasis immunotherapy in multi-author volume devoted to all aspects of cancer metastasis

    Olfactory responses of the omnivorous generalist predator Dicyphus hesperusto plant and prey odours

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    Responses of female Dicyphus hesperus Knight (Heteroptera: Miridae) to the odours of plants and prey were tested in the laboratory using a Y-tube olfactometer. Females were attracted to the odour of tomato leaves infested with nymphs of the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae), compared to uninfested leaves. No such attraction occurred to tomato leaves infested with two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae). When females were simultaneously presented with the odours of whitefly and mite-infested leaves, no preference for either odour was recorded. Similarly, females were attracted to the odour of pepper leaves infested with green peach aphids [Myzus persicae (Sulzer) (Homoptera: Aphididae)] compared to uninfested leaves, but were not attracted to the odour of pepper leaves infested with eggs of cabbage loopers, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae). When aphid-infested and looper-egg-infested pepper leaves were presented simultaneously, no preference for either odour was detected. The results are discussed as they relate to the evolution of infochemical use in generalist omnivorous predators. [ABSTRACT FROM AUTHOR]Peer reviewedfinal article publishedTrialeurodes vaporariorumMiridaeHeteropterabiological controlpeppertomatoTrichoplusia niMyzus persicaeTetranychus urtica
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