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This paper aims to characterize dynamics of a fire in the Large-Scale Demonstrator Malveira Fire Test, a full-scale fire experiment carried out in a disused industrial building in Portugal. The Malveira Fire Test is the second stage in the series of full-scale experimental programmes developed for the Real Fires for the Safe Design of Tall Buildings project at the University of Edinburgh. This experiment is intended to act as a real-building demonstration of fire dynamics in large open-floor plan compartments and has as objective to provide a data set to contrast methodologies aiming at design fire inputs representative of real fire dynamics in compartments typical of tall buildings. The Malveira Fire Test showed three distinct fire behaviour modes characterised by the ratio between the velocities of the fire front (") and the burnout front (#$

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The adjustment of the location of the anastomosis of the LVAD outflow cannula as well as its angle of incidence plays a significant role in the level of thromboembolisms. By proper adjustment in this CFD study of a synthetic model of an aortic arch bed, we found that nearly a 50% reduction in cerebral embolism could be achieved for a configuration consisting of a shallow angle of implantation over a baseline normal incidence of the LVAD cannula. Within the limitations of our model, we have established that the LVAD implantation geometry is an important factor and should be taken into consideration when implanting an LVAD. It is possible that other parameters such as distance of the LVAD outflow cannula to the root of the IA could affect the thrombi embolisation probabilities. However, the results of this study suggest that the risk of stroke may be significantly reduced by as much as 50% by tailoring the VAD implantation by a simple surgical manoeuvre. The results of this line of research may ultimately lead to techniques that can be used to estimate the optimal LVAD configuration in a patient-specific manner by pre-operative imaging.

This paper reviews some of the recent developments of microcellular injection molding, which is capable of producing parts with excellent dimensional stability using lower injection pressure, shorter cycle time, and less material. Process conditions as well as nano/micro-fillers such as nanoclay and core–shell rubber have a strong influence on cell density and cell size, hence, the final material properties of the molded parts. The addition of nano/micro-fillers at optimum loading levels can generally facilitate the formation of microcellular plastics with higher cell density and smaller cell size leading to superior mechanical properties. The novel integration of a solid plastic surface with a microcellular plastic core via the co-injection molding technique has been investigated to achieve Class “A” surfaces and improved material performance. An improved mathematical model has been developed to simulate the cell growth behavior in the microcellular injection molding process.

A mathematical formulation and numerical simulation for non‐isothermal cell growth during the post‐filling stage of microcellular injection molding have been developed. The numerical implementation solves the energy equation, the continuity equation, and a group of equations that describe the mass diffusion of dissolved gas and growth of micro‐cells in a microcellular injection molded part. The “unit‐cell” model employed in this study takes into account the effects of injection and packing pressures, melt and mold temperatures, and super‐critical fluid content on the material properties of the polymer‐gas solution and the cell growth. The material system studied is a microcellular injection molded polyamide 6 (PA‐6) resin. Two Arrhenius‐type equations are used to estimate the coefficients of mass diffusion and solubility for the polymer‐gas solution as functions of temperature. The dependence of the surface tension on the temperature is also included in this study. The numerical results in terms of cell size across the sprue diameter agree fairly well with the experimental observation. The predicted pressure profile at the sprue location has also been found to be in good agreement with the dynamics of the cell growth. Whereas for conventional injection molding the pressure of the system tends to decay monotonously, the pressure profile in microcellular injection molding exhibits an initial decay resulting from cooling and the absence of packing followed by an increase due to cell growth that expands the polymer‐gas solution and helps to pack out the mold uniformly. Polym. Eng. Sci. 44:2274–2287, 2004. © 2004 Society of Plastics Engineers.

Knowledge of the first principles defining fire behaviour in large enclosures remains limited despite their common use in modern tall buildings. The evolution of a fire in large enclosures can be defined by the relationship between the flame front and burnout velocities (𝑉 " /𝑉 $% ). The mechanisms governing flame spread and burnout are investigated using four full-scale enclosure fire experiments with high porosity wood cribs with similar enclosure geometries. Flame and burnout fronts position and velocity are estimated using video data. Velocities are affected by the heat feedback from the enclosure and smoke layer to the fuel. The spread velocity shows two regimes, a critical heat flux below which there is no spread (𝑞̇( ,*+,-.. ) and a heat flux that defines the onset of very rapid flame spread (𝑞̇+ (,*+,-.. ). A phenomenological model is developed to help identify the underlying mechanisms controlling the transition between the different spread modes. Both the model and data show that 𝑞̇( ,*+,-.. is controlled by the fuel's surface temperature ahead of the flame front, and that 𝑞̇( ,*+,-.. reduces as the surface temperature approximates steady state. The magnitude of 𝑞̇+ (,*+,-.. is constant and is mainly delivered by the flame heat flux. The dependence of the burnout front velocity to the external radiation is found to be weak. NomenclatureA area b stick thickness C crib burning constant hT total heat transfer coefficient Lv latent heat of vaporisation 𝑚 . mass per unit length 𝑚̇0 .. burning rate per unit area 𝑚̇1 .. free burning rate per unit area 𝑚̇+ .. radiation enhanced burning rate per unit area 𝑞2 ..