3D printed grid shell in ice composite

This paper presents the design of a grid shell that is made of fibre reinforced ice and constructed by combining additive manufacturing with an inflatable mould. While previous fibre reinforced ice structures were constructed by spraying, additive manufacturing with ice has not yet been tested before. Additive manufacturing is a stepwise production technique where material is being added layer by layer, resulting in a high degree of formability. Combining this printing technique with sustainable materials such as ice makes it possible to develop more sustainable structures and building applications in cold environments such as Mars or the poles. To test this application, a grid shell of fibre reinforced ice was designed and eventually constructed. The grid shell was designed by considering the design constraints of the inflatable mould that needed to support the wet ice layers during construction. The structural capacity of the grid shell was enhanced by performing an optimization procedure on the gridlines. In the end, a theoretical failure load calculation shows that the middle part of the structure could carry more than 6000 kg of additional load. To test this finding, the constructed grid shell was loaded on site with approximately 3000 kg, without showing any signs of failure. By designing and testing this innovative object, this project illustrates that additive manufacturing can successfully be applied for other structural applications such as sculptures, moulding and Mars missions.</p

Verslag van de ontwerpdag op 3 februari 2004

Verslag van de ontwerpdag van het project: "Houden van hennen". Op deze dag is een aanzet gegeven om te komen tot een nieuw houderijsysteem. Het project wordt systematisch aangepakt om te zorgen dat aan zoveel mogelijk wensen van belanghebbenden kan worden voldaa

Screening for coping style increases the power of gene expression studies

Background: Individuals of many vertebrate species show different stress coping styles and these have a striking influence on how gene expression shifts in response to a variety of challenges. Principal Findings: This is clearly illustrated by a study in which common carp displaying behavioural predictors of different coping styles (characterised by a proactive, adrenaline-based or a reactive, cortisol-based response) were subjected to inflammatory challenge and specific gene transcripts measured in individual brains. Proactive and reactive fish differed in baseline gene expression and also showed diametrically opposite responses to the challenge for 80% of the genes investigated. Significance: Incorporating coping style as an explanatory variable can account for some the unexplained variation that is common in gene expression studies, can uncover important effects that would otherwise have passed unnoticed and greatly enhances the interpretive value of gene expression data

Does rearing laying hens in aviaries adversely affect long-term welfare following transfer to furnished cages?

This study tests the hypothesis that hens that are reared in aviaries but produce in furnished cages experience poorer welfare in production than hens reared in caged systems. This hypothesis is based on the suggestion that the spatial restriction associated with the transfer from aviaries to cages results in frustration or stress for the aviary reared birds. To assess the difference in welfare between aviary and cage reared hens in production, non-beak trimmed white leghorn birds from both rearing backgrounds were filmed at a commercial farm that used furnished cage housing. The videos were taken at 19 and 21 weeks of age, following the birds' transition to the production environment at 16 weeks. Videos were analysed in terms of the performance of aversion-related behaviour in undisturbed birds, comfort behaviour in undisturbed birds, and alert behaviour directed to a novel object in the home cage. A decrease in the performance of the former behaviour and increase in the performance of the latter two behaviours indicates improved welfare. The results showed that aviary reared birds performed more alert behaviour near to the object than did cage reared birds at 19 but not at 21 weeks of age (P = 0.03). Blood glucose concentrations did not differ between the treatments (P>0.10). There was a significant difference in mortality between treatments (P = 0.000), with more death in aviary reared birds (5.52%) compared to cage birds (2.48%). The higher mortality of aviary-reared birds indicates a negative effect of aviary rearing on bird welfare, whereas the higher duration of alert behavior suggests a positive effect of aviary rearing