@incollection{UlrichSchlegelMertensetal., author = {Ulrich, Rainer G. and Schlegel, Matthias and Mertens, Marc and Groschup, Martin H. and Schmidt-Chanasit, Jonas and Plenge-B{\"o}nig, Anita and Jacob, Jens and Pelz, Hans-Joachim and Freise, Jona and Wenk, Matthias and Thiel, J{\"o}rg and Triebenbacher, Cornelia and Schmolz, Eric and Kurth, Andreas and Kr{\"u}ger, Frank and R{\"u}he, Ferdinand and Kiffner, Christian and Ansorge, Hermann and Gerwin, Werner and Wegener, Wolfgang and M{\"u}ller, J{\"o}rg and Bemmann, Margit and Wolf, Ronny and Otto, Lutz-Florian and Oehme, Rainer and Pfeffer, Martin and Heckel, Gerald and Schex, Susanne and Essbauer, Sandra S.}, title = {Netzwerk Nagetier-{\"u}bertragene Pathogene: Monitoring von Hantavirus-Infektionen in Deutschland}, series = {Wildhygiene, Wildtierkrankheiten, Parasiten, Epidemiologie}, booktitle = {Wildhygiene, Wildtierkrankheiten, Parasiten, Epidemiologie}, publisher = {Ges. f{\"u}r Wildtier- und Jagdforschung}, address = {Halle/Saale}, isbn = {978-378-88131-2-3}, issn = {1436-3895}, pages = {229 -- 250}, language = {de} } @misc{PfetschFuegenschuhGeissleretal., author = {Pfetsch, Marc E. and F{\"u}genschuh, Armin and Geißler, Bj{\"o}rn and Geißler, Nina and Gollmer, Ralf and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Martin, Alexander and Morsi, Antonio and R{\"o}vekamp, Jessica and Schewe, Lars and Schmidt, Martin and Schultz, R{\"u}diger and Schwarz, Robert and Schweiger, Jonas and Stangl, Claudia and Steinbach, Marc C. and Vigerske, Stefan and Willert, Bernhard M.}, title = {Validation of Nominations in Gas Network Optimization: Models, Methods, and Solutions}, series = {Optimization Methods and Software}, volume = {30}, journal = {Optimization Methods and Software}, number = {1}, issn = {1055-6788}, doi = {10.1080/10556788.2014.888426}, pages = {15 -- 53}, language = {en} } @misc{GroenkeArroziBronkallaetal., author = {Gr{\"o}nke, Martin and Arrozi, Ubed S. F. and Bronkalla, Nadine and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Woodcock, Thomas G. and Eckert, Victoria and Hao, Qi and Pl{\"u}schke, Laura and Lederer, Albena and Nielsch, Kornelius and B{\"u}chner, Bernd and Kaskel, Stefan and Hampel, Silke}, title = {Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity}, series = {Chemistry of Materials}, volume = {31}, journal = {Chemistry of Materials}, number = {14}, doi = {10.1021/acs.chemmater.9b01818}, pages = {5305 -- 5313}, abstract = {The transition metal halide α-titanium(III) chloride (α-TiCl₃) is a layered two-dimensional compound and a well-established Ziegler-Natta catalyst for the polymerization of ethylene. A new synthesis technique is used to obtain thin sheets of α-TiCl₃ that show exceptional physical properties in contrast to their bulk counterparts, due to an enlarged surface-to-volume ratio. Chemical vapor transport (CVT) of α-titanium(III) chloride directly on substrates results in microsheets that exhibit an improved catalytic effect. For rational planning of synthesis conditions, thermodynamic simulations of occurring gas-phase equilibria were performed. Based on these calculation results, crystal growth was achieved by adding GaCl₃via pure short term CVT in a temperature gradient of 700-600 K on yttrium-stabilized zirconia (YSZ) substrates. Phase pure, as-grown, single crystal sheets with high crystallinity and a thickness of around 4 μm were obtained. These thin sheets of α-TiCl₃ on YSZ substrates were implemented as catalysts for the ethylene polymerization reaction. A significant improvement of catalytic activity of 16\% was achieved, probably due to an increased surface-to-volume ratio. As a highlight, the as-grown microsheets were exfoliated subsequently to a thickness lower than 200 nm and an even higher catalytic activity of up to 24\% was confirmed experimentally due to delamination effects. This is the first time that an improved catalytic effect of α-TiCl₃ is observed as a result of downscaling from bulk to microsheets by CVT.}, language = {en} } @misc{FuegenschuhGeisslerGollmeretal., author = {F{\"u}genschuh, Armin and Geißler, Bj{\"o}rn and Gollmer, Ralf and Hayn, Christine and Henrion, Ren{\´e} and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Martin, Alexander and Mirkov, Radoslava and Morsi, Antonio and R{\"o}vekamp, Jessica and Schewe, Lars and Schmidt, Martin and Schultz, R{\"u}diger and Schwarz, Robert and Schweiger, Jonas and Stangl, Claudia and Steinbach, Marc C. and Willert, Bernhard M.}, title = {Mathematical Optimization for Challenging Network Planning Problems in Un- bundled Liberalized Gas Markets}, series = {Energy Systems}, volume = {5}, journal = {Energy Systems}, number = {3}, issn = {1868-3975}, doi = {10.1007/s12667-013-0099-8}, pages = {449 -- 473}, language = {en} } @misc{GroenkeSchmidtValldoretal., author = {Gr{\"o}nke, Martin and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Wolf, Daniel and Lubk, Axel and B{\"u}chner, Bernd and Hampel, Silke}, title = {Chemical vapor growth and delamination of α-RuCl3 nanosheets down to the monolayer limit}, series = {Nanoscale}, volume = {10}, journal = {Nanoscale}, number = {40}, issn = {2040-3372}, doi = {10.1039/C8NR04667K}, pages = {19014 -- 19022}, abstract = {2D layered honeycomb magnet α-ruthenium(III) chloride (α-RuCl3) is a promising candidate to realize a Kitaev spin model. As alteration of physical properties on the nanoscale is additionally intended, new synthesis approaches to obtain phase pure α-RuCl3 nanocrystals have been audited. Thermodynamic simulations of occurring gas phase equilibria were performed and optimization of synthesis conditions was achieved based on calculation results. Crystal growth succeeded via chemical vapor transport (CVT) in a temperature gradient of 973 K to 773 K on YSZ substrates. Single crystal sheets of high crystallinity with heights ≤ 30 nm were obtained via pure CVT. The crystal properties were characterized by means of optical and electron microscopy, AFM, SAED, micro-Raman and XPS proving their composition, morphology, crystallinity and phase-purity. A highlight of our study is the successful individualization of nanocrystals and the delamination of nanosheets on YSZ substrates down to the monolayer limit (≤ 1 nm) which was realized by means of substrate exfoliation and ultrasonication in a very reproducible way.}, language = {en} } @misc{GroenkePohfleppSchmidtetal., author = {Gr{\"o}nke, Martin and Pohflepp, Danny and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Wolf, Daniel and Hao, Qi and Steiner, Udo and B{\"u}chner, Bernd and Hampel, Silke}, title = {Simulation and synthesis of alpha-MoCl₃ nanosheets on substrates by short time chemical vapor transport}, series = {Nano-Structures \& Nano-Objects}, journal = {Nano-Structures \& Nano-Objects}, number = {19}, issn = {2352-507X}, doi = {10.1016/j.nanoso.2019.100324}, pages = {1 -- 7}, abstract = {Alpha-molybdenum(III) chloride (MoCl₃) belongs to layered van-der-Waals materials, which are in focus to exhibit interesting properties due to their weak chemical and magnetic interactions. Especially the structure of alpha-MoCl₃ has been discussed in terms of symmetry breaking dimerization of Mo atoms at room temperature, which might led to exotic ground states. By exploiting the 2D materials characteristics, an investigation of physical properties on the nanoscale is intended. We herein demonstrate the probably first approach to synthesize phase pure, as-grown alpha-MoCl₃ few-layer nanosheets by means of a pure short time chemical vapor transport (CVT) process. Vapor growth benefits from a one-step deposition of high crystalline alpha-MoCl₃ nanosheets without stacking faults on a substrate. Thus, mostly applied subsequent delamination, associated with the introduction of structural defects, becomes redundant. According to the CVT process thermodynamic simulations of gas phase equilibria have been performed and the synthesis conditions could be optimized based on the calculation results. By CVT the as-grown nanolayers are deposited on sapphire (Al₂O₃) substrates by applying a temperature gradient of 70 K from 743 K to 673 K. Single crystalline sheets with thicknesses ≤75 nm down to five layer (3 nm) could be obtained by using a pure CVT process. According to the deposited nanostructures we approve the desired composition, morphology, phase purity and high crystallinity by using several microscopy and spectroscopy techniques. Furthermore, we show micro-RAMAN measurements which hint at a slight increase in phonon energies for nanosheets in comparison to the corresponding bulk phase.}, language = {en} } @misc{FroeschkeWolfHantuschetal., author = {Froeschke, Samuel and Wolf, Daniel and Hantusch, Martin and Giebeler, Lars and Wels, Martin and Gr{\"a}ßler, Nico and B{\"u}chner, Bernd and Schmidt, Peer and Hampel, Silke}, title = {Synthesis of micro- and nanosheets of CrCl3-RuCl3 solid solution by chemical vapour transport}, series = {Nanoscale}, volume = {29}, journal = {Nanoscale}, number = {14}, issn = {2040-3372}, doi = {10.1039/D2NR01366E}, pages = {10483 -- 10492}, abstract = {Solid solutions of 2D transition metal trihalides are rapidly growing in interest for the search for new 2D materials with novel properties at nanoscale dimensions. In this regard, we present a synthesis method for the Cr1-xRuxCl3 solid solution and describe the behaviour of the unit cell parameters over the whole composition range, which in general follows Vegard's law in the range of a = 5.958(6)CrCl3 … 5.9731(5)RuCl3 {\AA}, b = 10.3328(20)CrCl3 … 10.34606(21)RuCl3 {\AA}, c = 6.110(5)CrCl3 … 6.0385(5)RuCl3 {\AA} and β = 108.522(15)CrCl3 … 108.8314(14)RuCl3 °. The synthesized solid solution powder was subsequently used to deposit micro- and nanosheets directly on a substrate by applying chemical vapour transport in a temperature gradient of 575 °C → 525 °C for 2 h and 650 °C → 600 °C for 0.5 h as a bottom-up approach without the need for an external transport agent. The observed chromium chloride enrichment of the deposited crystals is predicted by thermodynamic simulation. The results allow for a nanostructure synthesis of this solid solution with a predictable composition down to about 30 nm in height and lateral size of several μm. When applying a quick consecutive delamination step, it is possible to obtain few- and monolayer structures, which could be used for further studies of downscaling effects for the CrCl3-RuCl3 solid solution. X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy were used to confirm the purity and quality of the synthesized crystals.}, language = {en} } @misc{GroenkeBuschbeckSchmidtetal., author = {Gr{\"o}nke, Martin and Buschbeck, Benjamin and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Hao, Qi and Lubk, Axel and Wolf, Daniel and Steiner, Udo and B{\"u}chner, Bernd and Hampel, Silke}, title = {Chromium Trihalides CrX₃(X = Cl, Br, I): Direct Deposition of Micro- and Nanosheets on Substrates by Chemical Vapor Transport}, series = {Advanced Materials Interfaces}, volume = {6}, journal = {Advanced Materials Interfaces}, number = {24}, issn = {2196-7350}, doi = {10.1002/admi.201901410}, pages = {11}, abstract = {The experimental observation of intrinsic ferromagnetism in single layered chromium trihalides CrX₃ (X = Cl, Br, I) has gained outstanding attention recently due to their possible implementation in spintronic devices. However, the reproducible preparation of highly crystalline chromium(III) halide nanolayers without stacking faults is still an experimental challenge. As chromium trihalides consist of adjacent layers with weak interlayer coupling, the preparation of ultrathin CrX₃ nanosheets directly on substrates via vapor transport proves as an advantageous synthesis technique. It is demonstrated that vapor growth of ultrathin highly crystalline CrX₃ micro- and nanosheets succeeds directly on yttrium stabilized zirconia substrates in a one-step process via chemical vapor transport (CVT) in temperature gradients of 100 K (600°C → 500°C for CrCl₃ and 650°C → 550°C for CrBr₃ or CrI₃) without a need for subsequent delamination. Due to simulation results, optimization of synthesis conditions is realized and phase pure CrX₃ nanosheets with thicknesses ≤25 nm are obtained via short term CVT. The nanosheets morphology, crystallinity, and phase purity are analyzed by several techniques, including microscopy, diffraction, and spectroscopy. Furthermore, a potential subsequent delamination technique is demonstrated to give fast access to CrX₃ monolayers using the example of CrCl₃ .}, language = {en} } @misc{MaternSchmidt, author = {Matern, Antje and Schmidt, Martin}, title = {Sektor{\"u}bergreifende Koordination als Herausforderung nachhaltiger Infrastrukturentwicklung in St{\"a}dten}, series = {Informationen zur modernen Stadtgeschichte}, journal = {Informationen zur modernen Stadtgeschichte}, number = {1}, issn = {0340-1774}, pages = {70 -- 81}, abstract = {Der Beitrag widmet sich der aktuellen Transformation st{\"a}dtischer Infrastrukturen im Spannungsfeld von technologischen Neuerungen und Forderungen nach einer st{\"a}rkeren intersektoralen Koordination einerseits und der Fragmentierung st{\"a}dtischer Ver- und Entsorgung im Zuge der europ{\"a}ischen Liberalisierungspolitiken andererseits. Der Beitrag zielt darauf ab, den Stand und die H{\"u}rden der intersektoralen Koordination zwischen der Energie- und Wasserversorgung sowie der Abwasser- und Abfallentsorgung in deutschen Großst{\"a}dten zu charakterisieren. Die empirische Grundlage bietet ein DFG-Forschungsprojekt zur intersektoralen Koordination st{\"a}dtischer Infra- strukturen im Kontext nachhaltiger Stadtentwicklung. Anhand dieser Grundlage werden die Forderungen der Debatten zu Innovationen an intersektoralen Schnittstellen und Kritischen Infrastrukturen kritisch reflektiert und der Stand der Koordination st{\"a}dtischer Infrastrukturen gespiegelt. Angesichts der Ausdifferenzierungstrends wird gefragt, inwiefern die in den Debatten diskutierten Koordinationserfordernisse gegenw{\"a}rtig in den St{\"a}dten aufgegriffen werden (k{\"o}nnen). Der Beitrag schließt mit einem Blick auf die Perspektiven nachhaltiger, sektor{\"u}bergreifender Infrastrukturplanung und -politik.}, language = {de} } @misc{BimboeseNicolayBryketal., author = {Bimb{\"o}se, Martin and Nicolay, Alexander and Bryk, Alexander and Schmidt, Karl-Heinz and Morche, David}, title = {Investigations on intra- and interannual coarse sediment dynamics in a high-mountain catchment}, series = {Zeitschrift f{\"u}r Geomorphologie : Supplementband}, volume = {55}, journal = {Zeitschrift f{\"u}r Geomorphologie : Supplementband}, number = {2}, doi = {10.1127/0372-8854/2011/0055S2-0046}, pages = {67 -- 81}, language = {en} }