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    Typology of vulnerability of wheat farmers in Northeast Iran and implications for their adaptive capacity
    (Philadelphia, Pa : Taylor & Francis, 2019) Nooghabi, Saeedeh Nazari; Fleskens, Luuk; Sietz, Diana; Azadi, Hossein
    This study is focused on understanding sources and patterns of vulnerability of wheat smallholder farmers in Northeast Iran. We conducted a farm household survey and recorded multiple environmental and socio-economic attributes of 391 wheat smallholder farmers. A Vulnerability Scoping Diagram and Principal Component Analysis served to identify key factors determining wheat farmer's vulnerability. Also, we performed a cluster analysis to classify wheat farmers into three vulnerability types. Although drought affects all types as main environmental stressor, only for Cluster 2 was it the key vulnerability factor. For Clusters 1 and 3 socio-economic vulnerability components prevailed: for farmers categorized in Cluster 1 land consolidation was the main problem, while the current wheat import policy was the key problem for Cluster 3 farmers. Multiple tailored policies are needed that reduce the vulnerability of wheat farmers in all clusters. Supportive government policies should for example focus on avoiding price distortions from wheat imports for Cluster 3, land consolidation for Cluster 1 and collective tackling of pests and weeds for Cluster 2. Simultaneous provision of farm advisory services will benefit farmers of Clusters 1 and 3, while availability of improved seeds (drought-tolerant varieties) and other inputs will lower the environmental vulnerability of all farmers. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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    Template-assisted colloidal self-assembly of macroscopic magnetic metasurfaces
    (Cambridge [u.a.] : Soc., 2016) Mayer, Martin; Tebbe, Moritz; Kuttner, Christian; Schnepf, Max J.; König, Tobias A. F.; Fery, Andreas
    We demonstrate a template-assisted colloidal self-assembly approach for magnetic metasurfaces on macroscopic areas. The choice of anisotropic colloidal particle geometry, assembly pattern and metallic film is based on rational design criteria, taking advantage of mirror-charge effects for gold nanorods placed on gold film. Monodisperse gold nanorods prepared utilizing wet-chemistry are arranged with high precision on wrinkled templates to form linear array-type assemblies and subsequently transferred to a thin gold film. Due to the obtained particle-to-film distance of 1.1 nm, the plasmonic mode of the nanorod is able to couple efficiently with the supporting metallic film, giving rise to a magnetic mode in the visible spectrum (721 nm). Conventional UV-vis-NIR measurements in close correlation with electromagnetic simulations provide evidence for the presence of a magnetic resonance on the macroscopic area. The herein presented scalable lithography-free fabrication process paves the road towards colloidal functional metasurfaces with an optical response in the effective magnetic permeability.