A promising new treatment for large and complex bone defects is to implant specifically designed and additively manufactured synthetic bone scaffolds. Optimizing the scaffold design can potentially improve bone in-growth and prevent under- and over-loading of the adjacent tissue. This study aims to optimize synthetic bone scaffolds over multiple-length scales using the full-scale topology optimization approach, and to assess the effectiveness of this approach as an alternative to the currently used mono- and multi-scale optimization approaches for orthopaedic applications. We present a topology optimization formulation, which is matching the scaffold's mechanical properties to the surrounding tissue in compression. The scaffold's porous structure is tuneable to achieve the desired morphological properties to enhance bone in-growth. The proposed approach is demonstrated in-silico, using PEEK, cortical bone and titanium material properties in a 2D parameter study and on 3D designs. Full-scale topology optimization indicates a design improvement of 81% compared to the multi-scale approach. Furthermore, 3D designs for PEEK and titanium are additively manufactured to test the applicability of the method. With further development, the full-scale topology optimization approach is anticipated to offer a more effective alternative for optimizing orthopaedic structures compared to the currently used multi-scale methods.

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Transportation systems are complex yet vital infrastructures. Different stakeholders have to work together to guarantee the most efficient traffic of humans and goods. Challenges that stakeholders face in such infrastructure systems, like divergent interests and attitudes, make it hard to predict behaviour. To understand the complex systems including the behaviour of the stakeholders, it is relevant to model decision-making processes. For this reason, simulation games were developed. The present article focuses on two different case studies. Both are studies in which board games were used. After explaining each case study, a comparative section follows to give an overview about advantages and disadvantages of the use of board games in the transportation sector.

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Rail is a cost-effective and environment friendly freight transport modality when used efficiently. Stakeholders around Dutch ports are discouraged to choose rail due to uncertain train schedules and the dispersed nature of freight flows across terminals in the port. To understand the challenges and opportunities of freight transport using rail, we used a combined approach of modelling and simulation gaming as participative research method. In addition to a simulation game, we developed a metamodel to simulate all possible choices of the players in the game. We designed and executed simulation gaming sessions with professionals and students. Within these sessions, we collected data in the form of surveys and in-game observations on the behaviour of the players. We compared and contrasted the results of the metamodel with those of the gaming sessions. The main contribution of the research is the provision of a deep insight into the challenges and opportunities offered by efficient transportation of containers using rail. The combined approach allows us to assess the effectiveness of various incentives to consolidate freight, promote intermodal transportation and to encourage the development of efficient services for rail freight transport.@en