126 resultados para variational solutions


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Managing product information for product items during their whole lifetime is challenging, especially during their usage and end-of-life phases. A major challenge is how to keep a link between the product item and its associated information that may be stored in backend systems of different organizations. This chapter analyses and compares three approaches for addressing this task-that is, the electronic product code (EPC) Network, DIALOG, and World Wide Article Information (WWAI). The EPC network has three key strengths with respect to Product lifecycle management (PLM): First, it is an internationally accepted standard that is supported by a world-wide standards body (GSI). Second, the lookup mechanism helps to insulate the data on the tag from change. Third, because it is becoming widespread and that this tag can also be used for PLM. WWAI is more technically sophisticated than the other approaches. The DIALOG approach might be the most general purpose one of the three because it places few restrictions on the format of the data on the tag. © 2006 Copyright © 2006 Elsevier Ltd. All rights reserved.

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Fluid assessment methods, requiring small volumes and avoiding the need for jetting, are particularly useful in the design of functional fluids for inkjet printing applications. With the increasing use of complex (rather than Newtonian) fluids for manufacturing, single frequency fluid characterisation cannot reliably predict good jetting behaviour, owing to the range of shearing and extensional flow rates involved. However, the scope of inkjet fluid assessments (beyond achievement of a nominal viscosity within the print head design specification) is usually focused on the final application rather than the jetting processes. The experimental demonstration of the clear insufficiency of such approaches shows that fluid jetting can readily discriminate between fluids assessed as having similar LVE characterisation (within a factor of 2) for typical commercial rheometer measurements at shearing rates reaching 104rads-1.Jetting behaviour of weakly elastic dilute linear polystyrene solutions, for molecular weights of 110-488. kDa, recorded using high speed video was compared with recent results from numerical modelling and capillary thinning studies of the same solutions.The jetting images show behaviour ranging from near-Newtonian to "beads-on-a-string". The inkjet printing behaviour does not correlate simply with the measured extensional relaxation times or Zimm times, but may be consistent with non-linear extensibility L and the production of fully extended polymer molecules in the thinning jet ligament.Fluid test methods allowing a more complete characterisation of NLVE parameters are needed to assess inkjet printing feasibility prior to directly jetting complex fluids. At the present time, directly jetting such fluids may prove to be the only alternative. © 2014 The Authors.