A production planning system to continuously integrate the characteristics of reconfigurable manufacturing systems

Operation in a dynamic environment requires companies to constantly adapt their manufacturing systems to stay competitive. One approach to manufacturing is the use of reconfigurable manufacturing systems (RMS). Current production planning approaches cannot model and realize the production-side adaptions available in RMS. In this article a novel planning system for modeling that continuously integrates the key characteristics of RMS in production planning and control (PPC) is presented. First, the challenges for production planning using RMS are defined. A feasible planning system is then presented, based on modeling and specification approaches, followed by a planning method to realize capacity scalability and functionality changes in planning processes. Finally, a prototypical application is outlined and the planning system is evaluated with the help of different production scenarios. The application results demonstrate the feasibility of the planning system as well as the potential improvement of typical key performance indicators in manufacturing.     

Study of pyrolysis and upward flame spread on charring materials—Part I: Experimental study

In this paper, we describe the results from an experimental campaign, focused on vertical upward flame spread over a charring material. First, for validation purposes of simulation tools, we report on cone calorimeter results for square (9.8cm×9.8cm), 1.65 cm thick, medium density fibre samples, mounted horizontally. Temperature is shown at the surface and at different depths. The mass of the sample is continuously measured. From the raw data, we derive the temporal evolution of the mass loss rate due to pyrolysis. Different externally imposed heat fluxes are investigated (20, 30 and 50kW/m²), onto dry and wet material. Afterwards, for the configuration of two particle board plates (0.025 m thick, 0.4 m wide and 2.5 m high), vertically mounted face to face is considered. Two different horizontal spacing distances between the two plates are studied (30.5 and 10.5 cm). The purpose of this set‐up is to investigate the vertical upward flame spread with strong radiative heat feedback. To that purpose, the temporal evolution of surface temperature is measured over the height of the plates. The measurement data are used to test a pyrolysis model in numerical simulations. Copyright © 2010 John Wiley & Sons, Ltd.     

Experimental investigation into the influence of ignition location on flame spread and heat release rates of polyurethane foam slabs

This study presents the results from a set of 11 large‐scale open fire tests performed on flexible polyurethane foam slabs/mattresses. The purpose of the study was to investigate the influence of the ignition location on the fire behaviour of the foam slabs and to generate data on a highly characterised material that could be used for modelling work in the future. A method for obtaining spatially resolved flame spread data for this type of material was presented using a gridded array of 5 × 10 thermocouples placed on the underside the foam slab and from this, flame spread was examined using three different approaches. The heat release rate (HRR) results showed clear shapes forming that were dependent on the ignition location, with two distinct behaviours being observed between the various different ignition locations, this was also observed in the calculated flame spread rate (FSR) data. Results within an individual test, showed the calculated range of FSRs over the geometry of the slab varied between approximately 1 and 8 mm/s depending on the ignition location. The average FSR values between tests varied between 3 and 7 mm/s and the maximum and minimum values were calculated to be approximately 11 and 2 mm/s respectively.     

Assessing the fire performance of electric cables (FIPEC)

The FIPEC project is a research project funded by DG XII of the European Commission and co‐financed by several European cable manufacturers, compounders, cable users and governmental research bodies. The FIPEC project has developed different levels of testing ranging from a small‐scale, cone calorimeter test procedure developed for cables and materials, a full‐scale test procedure based on the IEC 60332‐3, but utilising HRR and SPR measurements, to a real‐scale test. Copyright © 2001 John Wiley & Sons, Ltd.     

Selection of plasters and renders for salt laden masonry substrates

The choice of a repair plaster or render by architects often appears to be the result of fortuitous circumstances, such as prior experience with a plaster or a recommendation by a producer. Seldom is the choice based on a sound assessment of the state of the building and the wall that is to be repaired. The service life of the repair plaster/render (and of the building to be conserved) is determined by many factors. In this paper, the most important factors affecting the risk of damage caused by salt are discussed, taking into account both the service life of the repair plaster/render and the conservation requirements of the existing building. The characteristics and performance of the various types of mortar for repair plaster or render are also reviewed. Next an attempt is made to evaluate the significance of the different factors affecting the choice of mortar. Then, taking into account the degree of risk of damage and performance data of the various types of repair mortar, possible mortar choices can be made for a repair plaster with an adequate service life. The final choice will depend on the specific conservation requirements for the existing building fabric.     

Towards a more effective and reliable salt crystallization test for porous building materials: state of the art

The durability of building materials with respect to salt crystallization is commonly determined by accelerated weathering tests, carried out in the laboratory. An effective laboratory weathering test should assess the durability and, in the case of conservation of historic buildings, the compatibility of repair materials with those existing. Besides, the test should provide reliable results within a reasonable period of time, accelerating the deterioration process without however altering its mechanism. Despite several national and international standards, recommendations and guidelines, a commonly accepted testing protocol does not yet exist. Researchers often develop and apply their own procedure, a fact that complicates comparison between different studies. The RILEM Technical Committee 271 ASC has been set up with the scope of developing improved test procedures for the assessment of the behaviour of materials under the influence of salt crystallization, which should overcome the limitations of existing standards and recommendations. This paper constitutes one of the first results of the work of the Technical Committee. It critically reviews the literature on salt crystallization tests, identifies advantages and limitations of the several test protocols and provides new ideas for the development of improved salt crystallization procedures.