104 research outputs found

    Framtida positionering inom svensk bilindustri - en kvalitativ studie i hur den alltmer miljömedvetna kunden kan mötas

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    Uppsatsen vill ge svar pÄ vad den svenska bilindustrin bör tÀnka pÄ i framtiden för att möta den alltmer miljömedvetna kunden. Intervjuer har genomförts med Volvo och Saab, branschexpertis samt konsumenter för att belysa olika synsÀtt kring dagens och framtida miljöproblem. Det vi kom fram till var att sÄvÀl Volvo som Saab bör fokusera pÄ fÀrre antal attribut. Företagen stÀrker sin miljöprofil om man ytterligare framhÄller bilens miljöpÄverkan snarare Àn andra, för mÄnga sjÀlvklara, attribut. Företagen stÀrker ocksÄ trovÀrdigheten i sin miljöpolitik om en ökad satsning pÄ mindre och brÀnslesnÄlare bilar genomförs. Volvo och Saab bör inte fokusera alltför mycket pÄ etanol eftersom etanolen har visat sig ha kritiska anhÀngare, bl.a. till framstÀllningen av ett sÄdant drivmedel

    A Dual View on IT Challenges in Corporate Divestments and Acquisitions

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    Acquisitions of new businesses and divestments of existing ones are frequently components of large organizations’ corporate strategies. In both acquisitions and divestments, corporate IT infrastructure plays a critical role for realizing business objectives. In this paper, we take a dual view of the IT-related challenges in divestment and acquisition strategies, studying them as a single integrated transaction between a buyer and a seller and investigating how the IT carve-out and IT integration strategies influence each other. The extant literature on the interaction between carve-outs and integration strategies is an empty set. Here, we begin to shed light to the limitations of the carve-out contract, the processes of carving out a business unit from one and integrating it into another multi-business organization, asymmetries in both parties’ preferences for an IT transaction process and its influence on arising challenges and organization performance

    Wake Development behind Paired Wings with Tip and Root Trailing Vortices: Consequences for Animal Flight Force Estimates

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    Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV) of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body), angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals

    Visualization of coronary arteries in paediatric patients using whole-heart coronary magnetic resonance angiography: comparison of image-navigation and the standard approach for respiratory motion compensation

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    Aims: To investigate the use of respiratory motion compensation using image-based navigation (iNAV) with constant respiratory efficiency using single end-expiratory thresholding (CRUISE) for coronary magnetic resonance angiography (CMRA), and compare it to the conventional diaphragmatic navigator (dNAV) in paediatric patients with congenital or suspected heart disease. Methods: iNAV allowed direct tracking of the respiratory heart motion and was generated using balanced steady state free precession startup echoes. Respiratory gating was achieved using CRUISE with a fixed 50% efficiency. Whole-heart CMRA was acquired with 1.3mm isotropic resolution. For comparison, CMRA with identical imaging parameters were acquired using dNAV. Scan time, visualization of coronary artery origins and mid-course, imaging quality and sharpness was compared between the two sequences. Results: Forty patients (13 females; median weight: 44 kg; median age: 12.6, range: 3 months–17 years) were enrolled. 25 scans were performed in awake patients. A contrast agent was used in 22 patients. The scan time was significantly reduced using iNAV for awake patients (iNAV 7:48 ± 1:26 vs dNAV 9:48 ± 3:11, P = 0.01) but not for patients under general anaesthesia (iNAV = 6:55 ± 1:50 versus dNAV = 6:32 ± 2:16; P = 0.32). In 98% of the cases, iNAV image quality had an equal or higher score than dNAV. The visual score analysis showed a clear difference, favouring iNAV (P = 0.002). The right coronary artery and the left anterior descending vessel sharpness was significantly improved (iNAV: 56.8% ± 10.1% vs dNAV: 53.7% ± 9.9%, P < 0.002 and iNAV: 55.8% ± 8.6% vs dNAV: 53% ± 9.2%, P = 0.001, respectively). Conclusion: iNAV allows for a higher success-rate and clearer depiction of the mid-course of coronary arteries in paediatric patients. Its acquisition time is shorter in awake patients and image quality score is equal or superior to the conventional method in most cases.Medical Engineering at King’s College London WT 088641/Z/09/ZBHF Centre of Excellence RE/08/0
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