@article{EdipSesovButenwegetal.2018,
  author    = {Edip, K. and Sesov, V. and Butenweg, Christoph and Bojadjieva, J.},
  title     = {Development of coupled numerical model for simulation of multiphase soil},
  series = {Computers and Geotechnics},
  volume    = {96},
  journal   = {Computers and Geotechnics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0266-352X},
  doi       = {10.1016/j.compgeo.2017.08.016},
  pages     = {118 -- 131},
  year      = {2018},
  abstract  = {In this paper, a coupled multiphase model considering both non-linearities of water retention curves and solid state modeling is proposed. The solid displacements and the pressures of both water and air phases are unknowns of the proposed model. The finite element method is used to solve the governing differential equations. The proposed method is demonstrated through simulation of seepage test and partially consolidation problem. Then, implementation of the model is done by using hypoplasticity for the solid phase and analyzing the fully saturated triaxial experiments. In integration of the constitutive law error controlling is improved and comparisons done accordingly. In this work, the advantages and limitations of the numerical model are discussed.},
  language  = {en}
}
@article{RuppRiekeHandschuhetal.2020,
  author    = {Rupp, Matthias and Rieke, Christian and Handschuh, Nils and Kuperjans, Isabel},
  title     = {Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities},
  series = {Transportation Research Part D: Transport and Environment},
  volume    = {81},
  journal   = {Transportation Research Part D: Transport and Environment},
  number    = {Article 102293},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1361-9209},
  doi       = {10.1016/j.trd.2020.102293},
  year      = {2020},
  abstract  = {In many cities, diesel buses are being replaced by electric buses with the aim of reducing local emissions and thus improving air quality. The protection of the environment and the health of the population is the highest priority of our society. For the transport companies that operate these buses, not only ecological issues but also economic issues are of great importance. Due to the high purchase costs of electric buses compared to conventional buses, operators are forced to use electric vehicles in a targeted manner in order to ensure amortization over the service life of the vehicles. A compromise between ecology and economy must be found in order to both protect the environment and ensure economical operation of the buses. In this study, we present a new methodology for optimizing the vehicles' charging time as a function of the parameters CO₂eq emissions and electricity costs. Based on recorded driving profiles in daily bus operation, the energy demands of conventional and electric buses are calculated for the passenger transportation in the city of Aachen in 2017. Different charging scenarios are defined to analyze the influence of the temporal variability of CO₂eq intensity and electricity price on the environmental impact and economy of the bus. For every individual day of a year, charging periods with the lowest and highest costs and emissions are identified and recommendations for daily bus operation are made. To enable both the ecological and economical operation of the bus, the parameters of electricity price and CO₂ are weighted differently, and several charging periods are proposed, taking into account the priorities previously set. A sensitivity analysis is carried out to evaluate the influence of selected parameters and to derive recommendations for improving the ecological and economic balance of the battery-powered electric vehicle. In all scenarios, the optimization of the charging period results in energy cost savings of a maximum of 13.6\% compared to charging at a fixed electricity price. The savings potential of CO₂eq emissions is similar, at 14.9\%. From an economic point of view, charging between 2 a.m. and 4 a.m. results in the lowest energy costs on average. The CO₂eq intensity is also low in this period, but midday charging leads to the largest savings in CO₂eq emissions. From a life cycle perspective, the electric bus is not economically competitive with the conventional bus. However, from an ecological point of view, the electric bus saves on average 37.5\% CO₂eq emissions over its service life compared to the diesel bus. The reduction potential is maximized if the electric vehicle exclusively consumes electricity from solar and wind power.},
  language  = {en}
}
@article{DotzauerPfeifferLaueretal.2019,
  author    = {Dotzauer, Martin and Pfeiffer, Diana and Lauer, Markus and Pohl, Marcel and Mauky, Eric and B{\"a}r, Katharina and Sonnleitner, Matthias and Z{\"o}rner, Wilfried and Hudde, Jessica and Schwarz, Bj{\"o}rn and Faßauer, Burkhardt and Dahmen, Markus and Rieke, Christian and Herbert, Johannes and Thr{\"a}n, Daniela},
  title     = {How to measure flexibility - Performance indicators for demand driven power generation from biogas plants},
  series = {Renewable Energy},
  journal   = {Renewable Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0960-1481},
  doi       = {10.1016/j.renene.2018.10.021},
  pages     = {135 -- 146},
  year      = {2019},
  language  = {en}
}
@article{RuppHandschuhRiekeetal.2019,
  author    = {Rupp, Matthias and Handschuh, Nils and Rieke, Christian and Kuperjans, Isabel},
  title     = {Contribution of country-specific electricity mix and charging time to environmental impact of battery electric vehicles: A case study of electric buses in Germany},
  series = {Applied Energy},
  volume    = {237},
  journal   = {Applied Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0306-2619},
  doi       = {10.1016/j.apenergy.2019.01.059},
  pages     = {618 -- 634},
  year      = {2019},
  language  = {en}
}
@article{RiekeStollenwerkDahmenetal.2018,
  author    = {Rieke, Christian and Stollenwerk, Dominik and Dahmen, Markus and Pieper, Martin},
  title     = {Modeling and optimization of a biogas plant for a demand-driven energy supply},
  series = {Energy},
  volume    = {145},
  journal   = {Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0360-5442},
  doi       = {10.1016/j.energy.2017.12.073},
  pages     = {657 -- 664},
  year      = {2018},
  abstract  = {Due to the Renewable Energy Act, in Germany it is planned to increase the amount of renewable energy carriers up to 60\%. One of the main problems is the fluctuating supply of wind and solar energy. Here biogas plants provide a solution, because a demand-driven supply is possible. Before running such a plant, it is necessary to simulate and optimize the process. This paper provides a new model of a biogas plant, which is as accurate as the standard ADM1 model. The advantage compared to ADM1 is that it is based on only four parameters compared to 28. Applying this model, an optimization was installed, which allows a demand-driven supply by biogas plants. Finally the results are confirmed by several experiments and measurements with a real test plant.},
  language  = {en}
}
@article{SrivastavaChaharSharmaetal.2017,
  author    = {Srivastava, A. and Chahar, V. and Sharma, V. and Sun, Y. and Bol, R. and Knolle, F. and Schnug, E. and Hoyler, Friedrich and Naskar, N. and Lahiri, S. and Patnaik, R.},
  title     = {Study of uranium toxicity using low-background gamma-ray spectrometry},
  series = {Journal of Radioanalytical and Nuclear Chemistry},
  journal   = {Journal of Radioanalytical and Nuclear Chemistry},
  number    = {Online first},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1588-2780},
  doi       = {10.1007/s10967-017-5466-9},
  pages     = {1 -- 7},
  year      = {2017},
  language  = {en}
}
@article{AlexopoulosHoffschmidt2017,
  author    = {Alexopoulos, Spiros and Hoffschmidt, Bernhard},
  title     = {Advances in solar tower technology},
  series = {Wiley interdisciplinary reviews : Energy and Environment : WIREs},
  volume    = {6},
  journal   = {Wiley interdisciplinary reviews : Energy and Environment : WIREs},
  number    = {1},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {2041-840X},
  doi       = {10.1002/wene.217},
  pages     = {1 -- 19},
  year      = {2017},
  language  = {en}
}
@article{JablonowskiKollmannNabeletal.2016,
  author    = {Jablonowski, Nicolai David and Kollmann, Tobias and Nabel, Moritz and Damm, Tatjana and Klose, Holger and M{\"u}ller, Michael and Bl{\"a}sing, Marc and Seebold, S{\"o}ren and Krafft, Simone and Kuperjans, Isabel and Dahmen, Markus and Schurr, Ulrich},
  title     = {Valorization of Sida (Sida hermaphrodita) biomass for multiple energy purposes},
  series = {GCB [Global Change Biology] Bioenergy},
  volume    = {9},
  journal   = {GCB [Global Change Biology] Bioenergy},
  number    = {1},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1757-1707 (online)},
  doi       = {10.1111/gcbb.12346},
  pages     = {202 -- 214},
  year      = {2016},
  abstract  = {The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70\% to 80\% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5-17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.},
  language  = {en}
}
@article{FleischhakerEvers2008,
  author    = {Fleischhaker, Robert and Evers, J{\"o}rg},
  title     = {Four-wave mixing enhanced white-light cavity},
  series = {Physical Review A - Atomic, molecular, and optical physics},
  volume    = {78},
  journal   = {Physical Review A - Atomic, molecular, and optical physics},
  number    = {5},
  issn      = {0556-2791},
  pages     = {051802(R)},
  year      = {2008},
  language  = {en}
}
@article{FleischhakerEvers2008,
  author    = {Fleischhaker, Robert and Evers, J{\"o}rg},
  title     = {Nonlinear effects in pulse propagation through Doppler-broadened closed-loop atomic media},
  series = {Physical Review A - Atomic, molecular, and optical physics},
  volume    = {77},
  journal   = {Physical Review A - Atomic, molecular, and optical physics},
  number    = {4},
  issn      = {1050-2947},
  doi       = {10.1103/PhysRevA.77.043805},
  pages     = {043805},
  year      = {2008},
  language  = {en}
}
@article{FleischhakerEversDey2010,
  author    = {Fleischhaker, Robert and Evers, J{\"o}rg and Dey, Tarak N.},
  title     = {Phase modulation induced by cooperative effects in electromagnetically induced transparency},
  series = {Physical Review A - Atomic, molecular, and optical physics},
  volume    = {82},
  journal   = {Physical Review A - Atomic, molecular, and optical physics},
  number    = {1},
  publisher = {AIP Publishing},
  address   = {Melville, NY},
  issn      = {1050-2947},
  doi       = {10.1103/PhysRevA.82.013815},
  pages     = {013815},
  year      = {2010},
  abstract  = {We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium.},
  language  = {en}
}
@article{FleischhakerEvers2011,
  author    = {Fleischhaker, Robert and Evers, J{\"o}rg},
  title     = {A Maxwell-Schr{\"o}dinger solver for quantum optical few-level systems},
  series = {Computer Physics Communications},
  volume    = {182},
  journal   = {Computer Physics Communications},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0010-4655},
  doi       = {10.1016/j.cpc.2010.10.018},
  pages     = {739 -- 747},
  year      = {2011},
  abstract  = {The msprop program presented in this work is capable of solving the Maxwell-Schr{\"o}dinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax-Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax-Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown.},
  language  = {en}
}
@article{FleischhakerKraussSchaettigeretal.2013,
  author    = {Fleischhaker, Robert and Krauß, Nico and Sch{\"a}ttiger, Farina and Dekorsy, Thomas},
  title     = {Consistent characterization of semiconductor saturable absorber mirrors with singe-pulse and pump-probe spectroscopy},
  series = {Optics Express},
  volume    = {21},
  journal   = {Optics Express},
  number    = {6},
  publisher = {Optica},
  address   = {Washington, DC},
  issn      = {1094-4087},
  doi       = {10.1364/OE.21.006764},
  pages     = {6764 -- 6776},
  year      = {2013},
  language  = {en}
}
@article{MahmoudiFleischhakerSahraietal.2008,
  author    = {Mahmoudi, Mohammad and Fleischhaker, Robert and Sahrai, Mostafa and Evers, J{\"o}rg},
  title     = {Group velocity control in the ultraviolet domain via interacting dark-state resonances},
  series = {Journal of physics B: Atomic, molecular and optical physics},
  volume    = {41},
  journal   = {Journal of physics B: Atomic, molecular and optical physics},
  number    = {2},
  issn      = {0953-4075},
  doi       = {10.1088/0953-4075/41/2/025504},
  pages     = {25504 -- 25600},
  year      = {2008},
  language  = {en}
}
@article{MykoniouButenwegHoltschoppenetal.2016,
  author    = {Mykoniou, Konstantin and Butenweg, Christoph and Holtschoppen, Britta and Klinkel, Sven},
  title     = {Seismic response analysis of adjacent liquid-storage tanks},
  series = {Earthquake engineering and structural dynamics},
  volume    = {45},
  journal   = {Earthquake engineering and structural dynamics},
  number    = {11},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1096-9845 (E-Journal); 0098-8847 (Print)},
  doi       = {10.1002/eqe.2726},
  pages     = {1779 -- 1796},
  year      = {2016},
  abstract  = {A refined substructure technique in the frequency domain is developed, which permits consideration of the interaction effects among adjacent containers through the supporting deformable soil medium. The tank-liquid systems are represented by means of mechanical models, whereas discrete springs and dashpots stand for the soil beneath the foundations. The proposed model is employed to assess the responses of adjacent circular, cylindrical tanks for harmonic and seismic excitations over wide range of tank proportions and soil conditions. The influence of the number, spatial arrangement of the containers and their distance on the overall system's behavior is addressed. The results indicate that the cross-interaction effects can substantially alter the impulsive components of response of each individual element in a tank farm. The degree of this impact is primarily controlled by the tank proportions and the proximity of the predominant natural frequencies of the shell-liquid-soil systems and the input seismic motion. The group effects should be not a priori disregarded, unless the tanks are founded on shallow soil deposit overlying very stiff material or bedrock.},
  language  = {en}
}
@article{TaddeiButenwegKlinkel2015,
  author    = {Taddei, Francesca and Butenweg, Christoph and Klinkel, S.},
  title     = {Parametric investigation of the soil-structure interaction effects on the dynamic behaviour of a shallow foundation supported wind turbine considering a layered soil},
  series = {Wind energy : an international journal for progress and applications in wind power conversion technology},
  volume    = {Volume 18},
  journal   = {Wind energy : an international journal for progress and applications in wind power conversion technology},
  number    = {Issue 3},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1099-1824 (E-Journal); 1095-4244 (Print)},
  doi       = {10.1002/we.1703},
  pages     = {399 -- 417},
  year      = {2015},
  language  = {en}
}
@article{EdipGarevskiButenwegetal.2013,
  author    = {Edip, Kemal and Garevski, Mihail and Butenweg, Christoph and Sesov, Vlatko and Cvetanovska, Julijana and Gjorgiev, Igor},
  title     = {Numerical simulation of geotechnical problems by coupled finite and infinite elements},
  series = {Journal of civil engineering and architecture},
  volume    = {7},
  journal   = {Journal of civil engineering and architecture},
  number    = {1},
  publisher = {David Publishing},
  address   = {Libertyville},
  issn      = {1934-7359 (E-Journal)},
  pages     = {68 -- 77},
  year      = {2013},
  language  = {en}
}
@article{HoltschoppenButenwegMeskouris2009,
  author    = {Holtschoppen, Britta and Butenweg, Christoph and Meskouris, Konstantin},
  title     = {Seismic design of non-structural components in industrial facilities},
  series = {International journal of engineering under uncertainty},
  volume    = {Volume 1},
  journal   = {International journal of engineering under uncertainty},
  issn      = {0975-4806},
  pages     = {1 -- 13},
  year      = {2009},
  language  = {en}
}
@article{GoemmelButenwegBolenderetal.2007,
  author    = {G{\"o}mmel, Andreas and Butenweg, Christoph and Bolender, Katrin and Grunendahl, Arno},
  title     = {A muscle controlled finite-element model of laryngeal abduction and adduction},
  series = {Computer methods in biomechanics and biomedical engineering},
  volume    = {Volume 10},
  journal   = {Computer methods in biomechanics and biomedical engineering},
  number    = {Issue 5},
  issn      = {1476-8259 (E-Journal); 1025-5842 (Print)},
  pages     = {377 -- 388},
  year      = {2007},
  language  = {en}
}
@article{RochefortVerverGrunendahletal.2005,
  author    = {Rochefort, E. de and Verver, M. and Grunendahl, A. and Mooi, H. and Butenweg, Christoph},
  title     = {Detailed modelling of the lumbar spine for investigations of low back pain},
  series = {SAE transactions : papers presented at Society and Section meetings / Society of Automotive Engineers},
  volume    = {Volume 114},
  journal   = {SAE transactions : papers presented at Society and Section meetings / Society of Automotive Engineers},
  number    = {Part 7},
  organization    = {Society of Automotive Engineers},
  issn      = {0096-736X},
  pages     = {788 -- 796},
  year      = {2005},
  language  = {en}
}