TY - CHAP A1 - Gerwin, Werner A1 - Raab, Thomas A1 - Seifert, Thomas T1 - Analyzing initial geomorphologic processes and structures: An alternative remote sensing approach T2 - EGU General Assembly 2010, held in Vienna, Austria, 02 – 07 May 2010 Y1 - 2010 N1 - EGU2010-11367 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Veste, Maik A1 - Littmann, Thomas A1 - Kunneke, Anton A1 - Du Toit, Ben A1 - Seifert, Thomas T1 - Windbreaks as part of climate-smart landscapes reduce evapotranspiration in vineyards, Western Cape Province, South Africa T2 - Plant, Soil and Environment N2 - Under the conditions of climate change in South Africa, ecological and technical measures are needed to reduce the water consumption of irrigated crops. Windbreak hedges are long-rated systems in agriculture that significantly reduce wind speed. Their possibilities to reduce evapotranspiration and water demand are being investigated at a vineyard in the Western Cape Province, South Africa. Detailed measurements of meteorological parameters relevant for the computation of reference and crop-specific evapotranspiration following the FAO 56 approaches within a vineyard in the Western Cape Province of South Africa have shown the beneficial effect of an existing hedgerow consisting of 6 m high poplars (Populus simonii (Carrière) Wesm.). With reference to a control station in the open field, the mean wind speed in a position about 18 m from the hedgerow at canopy level (2 m) was reduced by 27.6% over the entire year and by 39.2% over the summer growing season. This effect leads to a parallel reduction of reference evapotranspiration of 15.5% during the whole year and of 18.4% over the growing season. When applying empirical crop-specific Kc values for well-irrigated grapes, the reduction of evapotranspiration is 18.8% over the summer growth period. The introduced tree shelterbelts are a suitable eco-engineering approach to reduce water consumption and to enhance water saving in vineyards. KW - dry areas KW - viticulture KW - climate change KW - agroforestry Y1 - 2020 UR - https://www.agriculturejournals.cz/web/pse.htm?type=article&id=616_2019-PSE U6 - https://doi.org/10.17221/616/2019-PSE SN - 1214-1178 SN - 1805-9368 VL - 66 IS - 3 SP - 119 EP - 127 ER - TY - GEN A1 - Schneider, Anna A1 - Gerke, Horst H. A1 - Maurer, Thomas A1 - Seifert, Stefan A1 - Nenov, Rossen A1 - Hüttl, Reinhard F. T1 - Evaluation of remotely-sensed DEMs and modification based on plausibility rules and initial sediment budgets of an artificially-created catchment T2 - Earth Surface Processes and Landforms Y1 - 2012 SN - 1096-9837 VL - 37 IS - 7 SP - 708 EP - 725 ER - TY - CHAP A1 - Kittler, Martin A1 - Reiche, Manfred A1 - Mtchedlidze, T. A1 - Arguirov, Tzanimir V. A1 - Jia, Guobin A1 - Seifert, Winfried A1 - Suckow, Stephan A1 - Thomas, Wilhelm T1 - Stark effect at dislocations in silicon for modulation of a 1,5 um light emitter T2 - Silicon photonics III, 21 - 24 January 2008, San Jose, California, USA Y1 - 2008 SN - 978-0-8194-7073-7 PB - SPIE CY - Bellingham, Wash. ER - TY - GEN A1 - Brachmann, Erik A1 - Seifert, Marietta A1 - Neumann, Niels A1 - Alshwawreh, Nidal A1 - Uhlemann, Margitta A1 - Menzel, Siegfried A1 - Acker, Jörg A1 - Herold, Steven A1 - Hoffmann, Volker A1 - Gemming, Thomas T1 - Electroless-Deposited Platinum Antennas for Wireless Surface Acoustic Wave Sensors T2 - Materials N2 - In an effort to develop a cost-efficient technology for wireless high-temperature surface acoustic wave sensors, this study presents an evaluation of a combined method that integrates physical vapor deposition with electroless deposition for the fabrication of platinum-based planar antennas. The proposed manufacturing process becomes attractive for narrow, thick, and sparse metallizations for antennas in the MHz to GHz frequency range. In detail, narrow platinum-based lines of a width down to 40 μm were electroless-deposited on γ-Al2O3 substrates using different seed layers. At first, the electrolyte chemistry was optimized to obtain the highest deposition rate. Films with various thickness were prepared and the electrical resistivity, microstructure, and chemical composition in the as-prepared state and after annealing at temperatures up to 1100 ∘C were evaluated. Using these material parameters, the antenna was simulated with an electromagnetic full-wave simulation tool and then fabricated. The electrical parameters, including the S-parameters of the antenna, were measured. The agreement between the simulated and the realized antenna is then discussed. KW - wireless SAW sensor KW - high-temperature KW - antenna KW - electroless deposition KW - platinum film Y1 - 2019 UR - https://www.mdpi.com/1996-1944/12/7/1002 U6 - https://doi.org/10.3390/ma12071002 SN - 1996-1944 VL - 12 IS - 7 SP - 1002 EP - 1014 ER - TY - CHAP A1 - Schneider, Anna A1 - Gerke, Horst H. A1 - Maurer, Thomas A1 - Nenov, Rossen A1 - Seifert, Stefan T1 - Quantification of initial sediment redistribution in an artificially-created catchment using a time series of digital elevation models T2 - European Geosciences Union General Assembly 2011, Vienna, Austria, 03 – 08 April 2011 Y1 - 2011 UR - http://meetingorganizer.copernicus.org/EGU2011/EGU2011-4686.pdf N1 - EGU2011-4686 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Sheppard, Jonathan P. A1 - Bohn Reckziegel, Rafael A1 - Borrass, Lars A1 - Chirwa, Paxie W. A1 - Cuaranhua, Claudio J. A1 - Hassler, Sibylle K A1 - Hoffmeister, Svenja A1 - Kestel, Florian A1 - Maier, Rebekka A1 - Mälicke, Mirko A1 - Morhart, Christopher A1 - Ndlovu, Nicholas P. A1 - Veste, Maik A1 - Funk, Roger A1 - Lang, Friedericke A1 - Seifert, Thomas A1 - du Toit, Ben A1 - Kahle, Hans-Peter T1 - Agroforestry: An Appropriate and Sustainable Response to a Changing Climate in Southern Africa? T2 - Sustainability N2 - Agroforestry is often discussed as a strategy that can be used both for the adaptation to and the mitigation of climate change effects. The climate of southern Africa is predicted to be severely affected by such changes. With agriculture noted as the continent’s largest economic sector, issues such as food security and land degradation are in the forefront. In the light of such concerns we review the current literature to investigate if agroforestry systems (AFS) are a suitable response to the challenges besetting traditional agricultural caused by a changing climate. The benefits bestowed by AFS are multiple, offering ecosystem services, influence over crop production and positive impacts on rural livelihoods through provisioning and income generation. Nevertheless, knowledge gaps remain. We identify outstanding questions requiring further investigation such as the interplay between trees and crops and their combination, with a discussion of potential benefits. Furthermore, we identify deficiencies in the institutional and policy frameworks that underlie the adoption and stimulus of AFS in the southern African region. We uphold the concept that AFS remains an appropriate and sustainable response for an increased resilience against a changing climate in southern Africa for the benefit of livelihoods and multiple environmental values KW - agroforestry KW - Southern Africa Y1 - 2020 UR - https://www.mdpi.com/2071-1050/12/17/6796 U6 - https://doi.org/10.3390/su12176796 VL - 12 IS - 17 ER -