Building with Nature in landscape practice

In a world where increased prosperity has created a number of novel, ecosystem-related threats to people’s health and the economy, designing with nature offers a promising outlook to mute the potential negative impacts of our actions and to keep improving the quality of life worldwide. It also provides an alternative to an attitude that has been largely negligent towards our non-human fellow beings. Drawing from the experience of DS landscape architects, four actualized projects and two student master theses illustrate the challenges, opportunities and benefits that building with nature presents. These cases highlight four important lessons for designing with nature in rural and urban landscapes. First, considering the surrounding landscape as a starting point creates a deeper understanding of the situation at hand. This allows for better planning with the ecosystem and enhances the richness of its biodiversity once a project is delivered. Secondly, planning with nature creates the opportunity to let nature do some of the work. This can include water purification, drainage, and cooling. The third lesson is that designing with nature requires a long-term plan. Maintenance might be necessary, and the public may need to be patient to watch the ecosystem slowly flourish through the decades. Finally, creating a new kind of wilderness-imbued beauty to inspire public acceptance and to motivate stewardship is a promising method for establishing a successful long-term nature-inclusive design project. These and other lessons contribute to a field of design where incorporating nature is the status quo

Influence of alloying elements on the phase formation of ultrathin Ni (<10nm) on Si(001) substrates

The influence of Ni thickness on the formation of Nickel silicides was systematically investigated between 0 and 15nm. Annealing thickness gradients distinguishes films that agglomerate (>5nm) and films that are morphologically stable (<5nm). Alloying the initial Ni layer influences this critical thickness to higher (Al, Co) and lower (Ge, Pd, Pt) values. Pole figures and in situ XRD provides information to understand this observed shift in critical thickness

Receiver function mapping of mantle transition zone discontinuities beneath Alaska using scaled 3-D velocity corrections

SUMMARYThe mantle transition zone is the region between the globally observed major seismic velocity discontinuities around depths of 410 and 660 km and is important for determining the style of convection and mixing between the upper and the lower mantle. In this study, P-to-S converted waves, or receiver functions, are used to study these discontinuities beneath the Alaskan subduction zone, where the Pacific Plate subducts underneath the North American Plate. Previous tomographic models do not agree on the depth extent of the subducting slab, therefore improved imaging of the Earth structure underneath Alaska is required. We use 27 800 high quality radial receiver functions to make common conversion point stacks. Upper mantle velocity anomalies are accounted for by two recently published regional tomographic S-wave velocity models. Using these two tomographic models, we show that the discontinuity depths within our CCP stacks are highly dependent on the choice of velocity model, between which velocity anomaly magnitudes vary greatly. We design a quantitative test to show whether the anomalies in the velocity models are too strong or too weak, leading to over- or undercorrected discontinuity depths. We also show how this test can be used to rescale the 3-D velocity corrections in order to improve the discontinuity topography maps.After applying the appropriate corrections, we find a localized thicker mantle transition zone and an uplifted 410 discontinuity, which show that the slab has clearly penetrated into the mantle transition zone. Little topography is seen on the 660 discontinuity, indicating that the slab has probably not reached the lower mantle. In the southwest, P410s arrivals have very small amplitudes or no significant arrival at all. This could be caused by water or basalt in the subducting slab, reducing the strength at the 410, or by topography on the 410 discontinuity, preventing coherent stacking. In the southeast of Alaska, a thinner mantle transition zone is observed. This area corresponds to the location of a slab window, and thinning of the mantle transition zone may be caused by hot mantle upwellings.</jats:p