Millions of years of evolution have adapted spider webs to achieve a range of functionalities, including the well-known capture of prey, with efficient use of material. One feature that has escaped extensive investigation is the silk-on-silk connection joints within spider webs, particularly from a structural mechanics perspective. We report a joint theoretical and computational analysis of an idealized silk-on-silk fibre junction. By modifying the theory of multiple peeling, we quantitatively compare the performance of the system while systematically increasing the rigidity of the anchor thread, by both scaling the stress-strain response and the introduction of an applied pre-strain. The results of our study indicate that compliance is a virtue-the more extensible the anchorage, the tougher and stronger the connection becomes. In consideration of the theoretical model, in comparison with rigid substrates, a compliant anchorage enormously increases the effective adhesion strength (work required to detach), independent of the adhered thread itself, attributed to a nonlinear alignment between thread and anchor (contact peeling angle). The results can direct novel engineering design principles to achieve possible load transfer from compliant fibre-to-fibre anchorages, be they silk-on-silk or another, as-yet undeveloped, system.

Choosing a storage volume size for a rainwater catchment project is difficult because the overall volume needs to be large enough to meet the demand of users but not so high that it is never completely filled, which would waste money and space in the community. This newly developed Excel-based model can simplify choosing appropriate tank sizes for a rainwater catchment project by projecting the water availability in storage at multiple locations over the course of a year. For ease of use, the user can input monthly or daily data for improved accuracy. This tool also incorporates the ability to include adjustable daily demand, to distribute demand over multiple structures, to account for tank overflow, and to increase demand at other locations if one of them runs out of water. The water level at each location over one year and the local storage volume are shown on a plot, making it easy to determine what storage volume is necessary to provide enough water for the community. This tool was originally developed to determine appropriate storage volumes for a rainwater catchment project in Mkutani, Tanzania and has been adapted for general use.