@inproceedings{GerwinRaabSeifert, author = {Gerwin, Werner and Raab, Thomas and Seifert, Thomas}, title = {Analyzing initial geomorphologic processes and structures: An alternative remote sensing approach}, series = {EGU General Assembly 2010, held in Vienna, Austria, 02 - 07 May 2010}, booktitle = {EGU General Assembly 2010, held in Vienna, Austria, 02 - 07 May 2010}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{VesteLittmannKunnekeetal., author = {Veste, Maik and Littmann, Thomas and Kunneke, Anton and Du Toit, Ben and Seifert, Thomas}, title = {Windbreaks as part of climate-smart landscapes reduce evapotranspiration in vineyards, Western Cape Province, South Africa}, series = {Plant, Soil and Environment}, volume = {66}, journal = {Plant, Soil and Environment}, number = {3}, issn = {1214-1178}, doi = {10.17221/616/2019-PSE}, pages = {119 -- 127}, abstract = {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 (Carri{\`e}re) 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.}, language = {en} } @misc{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Seifert, Stefan and Nenov, Rossen and H{\"u}ttl, Reinhard F.}, title = {Evaluation of remotely-sensed DEMs and modification based on plausibility rules and initial sediment budgets of an artificially-created catchment}, series = {Earth Surface Processes and Landforms}, volume = {37}, journal = {Earth Surface Processes and Landforms}, number = {7}, issn = {1096-9837}, pages = {708 -- 725}, language = {en} } @inproceedings{KittlerReicheMtchedlidzeetal., author = {Kittler, Martin and Reiche, Manfred and Mtchedlidze, T. and Arguirov, Tzanimir V. and Jia, Guobin and Seifert, Winfried and Suckow, Stephan and Thomas, Wilhelm}, title = {Stark effect at dislocations in silicon for modulation of a 1,5 um light emitter}, series = {Silicon photonics III, 21 - 24 January 2008, San Jose, California, USA}, booktitle = {Silicon photonics III, 21 - 24 January 2008, San Jose, California, USA}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {978-0-8194-7073-7}, language = {en} } @misc{BrachmannSeifertNeumannetal., author = {Brachmann, Erik and Seifert, Marietta and Neumann, Niels and Alshwawreh, Nidal and Uhlemann, Margitta and Menzel, Siegfried and Acker, J{\"o}rg and Herold, Steven and Hoffmann, Volker and Gemming, Thomas}, title = {Electroless-Deposited Platinum Antennas for Wireless Surface Acoustic Wave Sensors}, series = {Materials}, volume = {12}, journal = {Materials}, number = {7}, issn = {1996-1944}, doi = {10.3390/ma12071002}, pages = {1002 -- 1014}, abstract = {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.}, language = {en} } @inproceedings{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Nenov, Rossen and Seifert, Stefan}, title = {Quantification of initial sediment redistribution in an artificially-created catchment using a time series of digital elevation models}, series = {European Geosciences Union General Assembly 2011, Vienna, Austria, 03 - 08 April 2011}, booktitle = {European Geosciences Union General Assembly 2011, Vienna, Austria, 03 - 08 April 2011}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{SheppardBohnReckziegelBorrassetal., author = {Sheppard, Jonathan P. and Bohn Reckziegel, Rafael and Borrass, Lars and Chirwa, Paxie W. and Cuaranhua, Claudio J. and Hassler, Sibylle K and Hoffmeister, Svenja and Kestel, Florian and Maier, Rebekka and M{\"a}licke, Mirko and Morhart, Christopher and Ndlovu, Nicholas P. and Veste, Maik and Funk, Roger and Lang, Friedericke and Seifert, Thomas and du Toit, Ben and Kahle, Hans-Peter}, title = {Agroforestry: An Appropriate and Sustainable Response to a Changing Climate in Southern Africa?}, series = {Sustainability}, volume = {12}, journal = {Sustainability}, number = {17}, doi = {10.3390/su12176796}, abstract = {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}, language = {en} }