@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{ScheweSulaimanBussetal., author = {Schewe, Lukas and Sulaiman, Cathy and Buß, Lars and Ewert, Moritz and Flege, Jan Ingo}, title = {In-situ photoemission electron microscopy investigation of mono- and bilayer graphene growth on Ru(10-10)}, series = {Verhandlungen der DPG}, journal = {Verhandlungen der DPG}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Epitaxial graphene growth has often been studied on close-packed transition metal substrates, e. g., the Ru(0001) surface, which is a well-studied model system for strong graphene-support interaction. Here, we focus on a Ru surface with different symmetry, i. e., the Ru(10-10) surface, to investigate the influence of the presumably modified graphene-substrate interaction on the growth of epitaxial monolayer and bilayer graphene (MLG, BLG) islands. The structural and chemical differences of the graphene on the two different surfaces are investigated by photoemission electron microscopy (PEEM), delivering information on both morphology and electronic structure. In-situ PEEM observation of graphene growth on the Ru(10-10) substrate by ethylene decomposition reveals the growth characteristics of MLG and BLG, the latter showing second layer nucleation via surface segregation of carbon. Furthermore, depending on growth temperature and relative orientation of the growing islands and surface steps, different growth characteristics are observed, in contrast to previous studies of the graphene/Ru(0001) system whereas similar electronic properties seem to prevail. Yet, when the MLG is decoupled from the Ru(10-10) substrate via intercalation of oxygen a distinct shift in work function is identified, slightly different from the resulting shift on Ru(0001).}, language = {en} } @misc{SulaimanScheweBussetal., author = {Sulaiman, Cathy and Schewe, Lukas and Buß, Lars and Ewert, Moritz and Flege, Jan Ingo}, title = {In-situ monolayer graphene growth on Ru(10-10): an electron microscopy study}, series = {Verhandlungen der DPG}, journal = {Verhandlungen der DPG}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {During the last decade, the controlled growth of monolayer (MLG) and bilayer graphene has extensively been studied on the hexagonal Ru(0001) surface, which is a system that is known to form strong chemical bonds at the metal-graphene interface. Yet, little attention was paid to the influence of the substrate orientation that was demonstrated to have a significant impact for graphene growth on the Ir(001) and Ir(111) surfaces, the latter exhibiting a weak coupling between the graphene and the support. Therefore, in this study we have grown graphene on the rectangular Ru(10-10) surface by segregation and ethylene-supported chemical vapor deposition. A photoemission and low-energy electron microscope (PEEM \& LEEM) has been utilized to directly characterize the MLG growth process with respect to variations in substrate temperature and step orientation. The expansion of the MLG islands is compared to the well-established carpet-growth mode on the Ru(0001) surface. These results have been complemented by probing of the occupied and unoccupied electronic structure of the islands using PEEM and intensity-voltage LEEM. Furthermore, the existence of two preferential surface reconstructions is identified via micro-illumination low-energy electron diffraction (LEED), whose spatial distribution is revealed by employing dark-field LEEM imaging.}, 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{FrankFuegenschuhHertyetal., author = {Frank, Martin and F{\"u}genschuh, Armin and Herty, Michael and Schewe, Lars}, title = {The Coolest Path Problem}, series = {Networks \& Heterogeneous Media}, volume = {5}, journal = {Networks \& Heterogeneous Media}, number = {1}, issn = {1438-0064}, doi = {10.3934/nhm.2010.5.143}, pages = {143 -- 162}, language = {en} }