163 research outputs found
Polling both in Mara
No full textMaurice Callens, Tom Gray, Charlie Coell, Harry Kellett, James Massey, Harry Johnson sitting at polling both in Mara Hall
Internal and external exploration for public service innovation-Measuring the impact of a climate for creativity and collaborative diversity on innovation
No full textPublic service innovation involves a process of creative exploration of new ideas, knowledge and perspectives. The article poses that creative exploration emerges from the combination of a climate for creativity that is active inside the organization, and collaborations with diverse actors that are present outside the organization. We test the effect of these conditions on innovation using data from the Australian Public Service. Our findings demonstrate that both a climate for creativity and collaborative diversity are positively related to innovation, yet a tipping point exists at which the positive effects of collaborative diversity on innovation turn negative.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Fonds Wetenschappelijk Onderzoek (1244720N) This article has benefited from the interaction within the GOVTRUST Centre of Excellence (University of Antwerp, Belgium)
The curious case of curvature: Geometric perspectives on biomaterial design
No full textThe rapidly expanding field of tissue engineering presents enticing, yet demanding challenges for scientists and engineers across many different disciplines. The ultimate goal of tissue engineering is ambitious: to regenerate damaged or missing tissue in its full complexity, either in vitro or in situ, and restore organ function. In addition to cells and biochemical factors, biomaterial scaffolds form the other essential ingredient within the tissue engineering paradigm. These scaffolds support, guide, and stimulate neotissue formation and are rationally designed to meet the desired balance between mechanical, mass transport and biological properties necessary for regeneration and implantation.Biomaterials & Tissue Biomechanic
Genetic and demographic signatures of population fragmentation in a cooperatively breeding bird from South-East Kenya
No full textThe Effects of Polymer Architecture on Dry Adhesion
No full textUnlike traditional wet-adhesives, dry adhesives are bioinspired solid polymers that owe their adhesion to hierarchical structures. Gecko’s are the most recognizable living creatures relying on this concept to climb walls. A close look at the gecko’s fingers reveals a hierarchical system of micro-and nanoscale filaments. These ensure excellent adaptability and contact to (rough) surfaces and the formation of a large amount of close-range van der Waals surface interactions. The reversible nature of these bonds allows for reversible and repeatable adhesion. This hierarchical system has been identified as the main reason for dry adhesion and has been object of intense research to manufacture man-made solid adhesives. Despite the many efforts, there are some unclear aspects resulting from contradictory scientific reports and a strong focus on a particular polymer chemistry used to make the hierarchical structures. This has left the effects of the material choice on dry adhesion largely neglected. In this research project, we aimed to shed some light on the role of different polymer architecture features on dry adhesion. Most available research has focused on the use of commercial siloxane elastomers that offer almost no control on the polymer synthesis. Instead, we opted to use thermoplastic polyurethane chemistry due to the large versatility this chemistry offers in terms of modification of relevant polymer architecture features. In the absence of available works on thermoplastics a new manufacturing process of such hierarchical structures had to be developed relying on heating, pressure and vacuum to respectively melt the polymer, overcome the high viscosity and impede oxidation. We studied the effects of the polymer architecture and properties on adhesion using a single micropillar architecture and varying the chemical composition (polyol length, aromatic content, hard/soft block ratio), the testing temperature and the pull-off speed. As to the polymer architecture, the best results were found with a short polyol and the lowest hard block fraction that still guaranteed structural integrity. Next to that, it was found that having aromatic rings in the hard segments was crucial, likely due to its beneficial effect on nanophase separation. With those compositions, values exceeding those of state-of-the-art dry adhesives were found, with a maximum of 440 kPa at the Tg and high retraction speeds. Furthermore, we show that while existing models are valid for thermoplastic polyurethanes well below their Tg, once they exhibit viscoelastic behaviour, the loss factor is a much more reliable indicator of performance than the reported stiffness. The effect of the surface energy was also evident but minimal compared to the mechanical properties of the polymers.Aerospace Engineerin
Design of a kite seat with optimal ergonomic fit, for use in surfschools
No full textThe goal of this thesis is to design a kite seat with optimal ergonomic fit for beginners in kite schools. Before designing, it is important to understand the context and create anthropometric guidelines for the target group. The seat will be used for sit-kitesurfing, which originates from the sport kitesurfing. Its target group focuses on people with a physical disability such as SCI, amputees or spina bifida. The difference with kitesurfing is that the setup exists of a seat mounted on an aluminium frame. This frame goes onto a specially designed board for this purpose.The project has been set up in cooperation with the Willem Hooft Foundation. This is an organisation aimed at improving the accessibility of adapted watersports, with a focus on kitesurfing. Research shows that accessibility to sports in general is lower for people with a physical disability. However, this is expected to be even lower for sit-kitesurfing. Currently, the availability of adapted courses is limited and people are left to themselves. This means buying all the gear before even trying the sport and learning the sport without qualified instructors. Improving the accessibility is done in cooperation with kiteschools offering adapted courses, where beginners can try out the sport in a safe environment.What stops most kiteschools from offering these courses is the relatively high cost of the specialised gear. Currently, the biggest part of the costs consists of the kite seats. At least four out of seven different seat sizes are necessary to organise kite courses. Replacing those four to seven seats by a single, adaptable seat will greatly reduce the cost for kiteschools. Next to the financial aspect, there are practical and ergonomical benefits. An example is the time-consuming and difficult task of changing the right seat size to the frame. Ergonomically, the fit of these seats is often not optimised for the beginning kitesurfer of the target group.The context, literature and desktop research resulted in key insights and points of improvement. Where information was still lacking, additional user or expert interviews were performed. Anthropometric data has been gathered through existing datasets on DINED. However, this information was not specific for the target group. Additional manual measurements and 3D-scans are performed with 9 people fitting the target group. This pointed out the differences between the target group and the existing datasets, but also provided lacking anthropometric data such as thigh width and location of the trochanter. Next to that the difficulties became clear, as everybody is different. The main design goals gathered from the research are improving pressure distribution through an optimal and tight fit. Challenges are the varying location of the trochanter, shape of the buttocks and the thighs. The final design is an adjustable seat, reducing the amount of needed kite seats from at least four to one. This will greatly decrease investment costs, effort, time and storage. The project’s outcome includes anthropometric design guidelines for a kite seat and a 1:1 prototype to test the concept.Integrated Product Desig
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