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In jetting-based additive manufacturing, one or more droplet trains are deposited on a moving surface to fabricate layers in an additive approach. The impact behaviour of the droplets onto the surface defines the final fabricated layer properties in terms of geometry and surface finish. This paper reports on such behaviour when depositing a solution of a bio-degradable resin toward an ultimate goal of fabricating bone implants in an additive manufacturing process. The solution was jetted via a fixed single nozzle continuous piezoelectric printhead on a moving surface. The effect of two main process parameters, jetting frequency and substrate linear velocity, on the impact behaviour was investigated. Quantitative analysis was undertaken to investigate the droplet formation characteristics and droplet/surface interactions. The phenomena associated with the interaction at the front of the advancing liquid layer was correlated with the process conditions. The result was a classification of the droplet train/moving surface interactions into three main regimes depending on the droplet impingement characteristics and the surface motion.2

In building refurbishment projects, dynamic building simulation is popularly used to predict the energy saving potential of various refurbishment scenarios.However, in this process, it is not clear whether occupant behaviour should be carefully modelled due to the lack of evidence about its impact on the prediction results. To answer this question, this study selected an UK public building and used dynamic building simulation to predict the energy saving potential of common refurbishment measures, under various occupant behavioural conditions. The results revealed that for the case study building occupants' heating behaviour has a significant impact on the predicted energy saving potential of all evaluated refurbishment measures: when changing from passive heating users to active heating users, the energy saving potential was nearly doubled. Although occupants' window opening behaviour was not shown to be as important as heating behaviour for the refurbishment of the case study building, it has a specific influence on the refurbishment measure of increasing window layers: when windows are opened longer, the effectiveness of increasing window layers on promoting the building energy efficiency is decreased. According to the findings from this study, occupant behaviour should be considered as an important aspect in building refurbishment projects.

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An optical fibre sensor (OFS) for the online monitoring of the polymerization reaction is described in this paper. The sensor, based on Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) analysis, was used to study the reaction between diglycidyl ether bisphenol-A (DGEBA) and 2,2 0 -dimethyl-4,4 0 -methylenebis(cyclohexylamine) (DMMB-CHA). Changes in concentrations of reactants and products were monitored over the curing period at different temperatures by the FT-IR technique, and from DSC runs the variation in the enthalpy of reaction over time for different curing temperatures was determined. Plots of fractional conversions versus time from the two methods were produced and compared. An attempt to deduce glass transition temperatures from the fractional conversion curves produced by FT-IR is also described. This involved the use of the fitting polynomial calculated from the DSC results. As a result, a sensor designed for embedding into a system curing at elevated temperature was constructed and tested.