Melt electrowriting is an additive manufacturing technique capable of fabricating highly biomimetic polymer scaffolds with high‐resolution microarchitecture for a range of tissue engineering applications. The use of a rotating mandrel to fabricate tubular scaffolds using this technique is increasing in popularity; however, the translation of many novel scaffold designs that have been explored on flat collectors has yet to be realized using mandrels. This study reports novel tools to automatically generate scaffold gcode for several new tubular scaffold designs, investigating a range of auxetic pore geometries and open unit cell designs. Through optimization of printing parameters, the novel scaffold designs are successfully printed and mechanically tested to assess tensile properties. Open unit cells significantly reduce the tensile stiffness of scaffolds manufactured with closed pores. Auxetic scaffolds could also be widely tuned using the novel gcode generator tool to exhibit similar stress–strain profiles to typical crosshatch scaffolds but could be made to expand to desired radial dimensions. Finally, heterogeneous auxetic constructs are also fabricated with regions of various radial compliances. This study presents several, mechanically validated novel scaffold designs that are of interest for future applications in targeted tissue engineering product development as well as in soft robotic actuation.
Shipping emissions are known to have an impact on communities in coastal locations, especially near harbours. This study was carried out to monitor the air quality near the premier cruise ship terminal in Melbourne, over a continuous period of 98 days during the peak cruise ship season in Australia. As these emission plumes are intermittent and fluctuate spatially, a single fixed monitor is not suitable for their detection. To overcome this limitation, seven lowcost KOALA air quality monitors were spatially distributed, 4 at ground level and 3 on the upper balconies of two high-rise apartment blocks. The KOALA monitor measures PM2.5 and CO concentration in real time and transmits the data through the 3G network to an in-cloud database. The time profile showed numerous very high short-term PM2.5 concentration spikes coinciding with ship movements, some of them exceeding 200 μg m-3 for periods of 5-10 min. On average, the PM2.5 concentration during spike episodes was about 4-5 times over the normal background value of around10 μg m-3. As they lasted for very short times, these spikes did not contribute significantly to the overall 24-hour average values at any of the locations. However, the number of days when the latter value exceeded the national air quality standard was higher than at the nearest air quality station. We attribute this to the high pollution spikes. While the long-term health effects of elevated PM concentrations are known, there have been very few studies on the effect of short-term exposures to high spikes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.