The positive feedback loop between TSLP, IL-33 and their receptors, and Th2 cytokines may facilitate Th2-skewed inflammation in eosinophilic CRSwNP.

Hot tearing, or hot cracking, is one of the most severe solidification defects commonly encountered during casting. It is such a complicated phenomenon that a full understanding is still not yet achieved, though it has been extensively investigated for decades. Most contributions are still based on qualitative characterisations. The purpose of this work is to develop a method that can quantitatively evaluate and investigate hot tearing behaviour. The principle is based on contraction stress/force measurements. The measured contraction force has been proven to be able to evaluate the hot tearing susceptibility as a more straightforward and quantitative index. By analyzing the contraction force curve, information can be obtained for both the initiation and the propagation of the hot tear. With this method, the influence of mould temperature and Al content on hot tearing behaviour of Mg-Al binary alloys has been investigated. The contraction force curves also indicate that the liquid refilling plays an important role during the hot crack propagation. With a lower cooling rate and higher onset temperature of hot tear, the remaining liquid is more favourable to refill the initiated hot crack, and consequently interrupts the propagation of cracks or possibly completely heals the cracks.

Hot tearing (or hot cracking) is recognised in the foundry industry as a serious defect. Although it has been investigated for decades, understanding still stands at a qualitative level. In this work, investigations on hot tearing in the binary Mg-1Al (wt-%) alloy have been conducted, using a contraction stress measuring method which shows evidence of good repeatability. The results show that increasing mould temperature decreases hot tearing susceptibility for Mg-1Al due to a decreased cooling rate. The recorded contraction force curves also show that hot cracks initiate under all investigated mould temperatures; however, the crack propagation behaves differently. At lower mould temperatures, the crack propagates very fast, while at higher mould temperatures it propagates slowly. This indicates that a lower cooling rate allows a better chance for the retained liquid to refill the crack. Consequently this leads to partial or complete interruption of crack propagation.