To make electronic products fit for circular economy strategies such as life extension, refurbishment, and recycling, ease of disassembly is a key design quality. Several tools are available to assess the ease of disassembly of products during the design process, such as the ease of Disassembly Metric (eDiM) and Hotspot Mapping (HSM). The eDiM method uses the time-to-dismantle as a unit for calculating the ease of disassembly. The longer it takes to reach a priority part, the lower the ease of disassembly. Hotspot mapping scores the different parts in the product architecture and ranks them on its failure rate (priority parts), activity, time-to-disassemble, embodied environmental impact, and embodied economical value. These tools help designers prioritize which parts of the product need to be redesigned to improve its circularity. The eDiM tool is quick and easy to use but is based on generic proxy times, which may not be applicable to specific fastener designs or product types. On the other hand, the hotspot mapping tool uses actual recorded times to accurately identify disassembly hotspots. Recording the time-to-disassemble is more accurate, but is also more time consuming and depends on the operator's experience. Therefore it is difficult to come up with reproducible numbers. It is crucial to find the right balance for these tools, to be able to accurately identify hotspots while maintaining the usability. In this paper, we research how to develop product-specific proxy times in order to reduce the effort required for assessing hotspots. To reach our goal, we conducted a series of experiments to measure the actual disassembly times of different computer mice, and compared them with the predictions from eDiM. The results indicate that the tools provide accurate results for the most dominant fastener type used in this type of product (Phillips screws) but largely deviate from actual results for some other common fastening techniques, such as adhesives. Consequently, generic proxy times could not be used to correctly identify the product design hotspots. The authors suggest specific modifications to the ease-of-disassembly tools to improve their applicability, thereby supporting the design of circular electronics.

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• Background and Aims Ecosystem-based flood defence including salt-marsh as a key component is increasinglyapplied worldwide due to its multifunctionality and cost-effectiveness. While numerous experiments haveexplored the wave-attenuation effects of salt-marsh plants critical to flood protection, little is known about thephysiological and biochemical responses of these species to continuous wave exposure.
• Methods To address this knowledge gap, we developed a shallow-water wave simulator to expose individualSpartina alterniflora plants to waves in a greenhouse for 8 weeks. S. alterniflora individuals were partially submergedand experienced horizontal sinusoidal motion to mimic plant exposure to shallow water waves. A factorialexperiment was used to test the effects of three wave heights (4.1 cm, 5.5 cm and a no-wave control) and two waveperiods (2 s and 3 s) on the following key physiological and biochemical plant parameters: plant growth, antioxidantdefence and photosynthetic capacity.
• Key Results Comparison of wave treatment and control groups supported our hypotheses that wave exposureleads to oxidative stress in plants and suppresses plant photosynthetic capacity and thereby growth. In response,the wave-exposed plants exhibited activated antioxidant enzymes. Comparison between the different wave treatmentgroups suggested the wave effects to be generally correlated positively with wave height and negativelywith wave period, i.e. waves with greater height and frequency imposed more stress on plants. In addition, waveexposedplants tended to allocate more biomass to their roots. Such allocation is favourable because it enhancesroot anchorage against the wave impact.
• Conclusions Simulated wave exposure systems such as the one used here are an effective tool for studying theresponse of salt-marsh plants to long-term wave exposure, and so help inform ecosystem-based flood defence projectsin terms of plant selection, suitable transplantation locations and timing, etc. Given the projected variabilityof the global wave environment due to climate change, understanding plant response to long-term wave exposurehas important implications for salt-marsh conservation and its central role in natural flood defence.@en