TY  - JOUR
A1  - Taddei, Francesca
A1  - Butenweg, Christoph
A1  - Klinkel, S.
T1  - Parametric investigation of the soil-structure interaction effects on the dynamic behaviour of a shallow foundation supported wind turbine considering a layered soil
JF  - Wind energy : an international journal for progress and applications in wind power conversion technology
Y1  - 2015
U6  - http://dx.doi.org/10.1002/we.1703
SN  - 1099-1824 (E-Journal); 1095-4244 (Print)
VL  - Volume 18
IS  - Issue 3
SP  - 399
EP  - 417
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Chudoba, Rostislav
A1  - Butenweg, Christoph
A1  - Peiffer, F.
T1  - Technical information system for collaborative material research
JF  - Advances in engineering software
Y1  - 2004
U6  - http://dx.doi.org/10.1016/j.advengsoft.2004.03.021
SN  - 1873-5339 (E-Journal); 0965-9978 (Print)
VL  - Volume 35
IS  - Issue 10-11
SP  - 747
EP  - 756
ER  - 
TY  - JOUR
A1  - Holler, S.
A1  - Butenweg, Christoph
A1  - Noh, S.-Y.
A1  - Meskouris, Konstantin
T1  - Computational model of textile-reinforced concrete structures
JF  - Computers & structures : an international journal
Y1  - 2004
U6  - http://dx.doi.org/10.1016/j.compstruc.2004.03.076
SN  - 1879-2243 (E-Journal); 0045-7949 (Print)
VL  - Volume 82
IS  - Issues 23-26
SP  - 1971
EP  - 1979
ER  - 
TY  - JOUR
A1  - Holtschoppen, Britta
A1  - Butenweg, Christoph
A1  - Meskouris, Konstantin
T1  - Seismic design of non-structural components in industrial facilities
JF  - International journal of engineering under uncertainty
Y1  - 2009
SN  - 0975-4806
VL  - Volume 1
SP  - 1
EP  - 13
ER  - 
TY  - JOUR
A1  - Mahmoudi, Mohammad
A1  - Fleischhaker, Robert
A1  - Sahrai, Mostafa
A1  - Evers, Jörg
T1  - Group velocity control in the ultraviolet domain via interacting dark-state resonances
JF  - Journal of physics B: Atomic, molecular and optical physics
Y1  - 2008
U6  - http://dx.doi.org/10.1088/0953-4075/41/2/025504
SN  - 0953-4075
SN  - 1361-6455
VL  - 41
IS  - 2
SP  - 25504
EP  - 25600
ER  - 
TY  - JOUR
A1  - Fleischhaker, Robert
A1  - Krauß, Nico
A1  - Schättiger, Farina
A1  - Dekorsy, Thomas
T1  - Consistent characterization of semiconductor saturable absorber mirrors with singe-pulse and pump-probe spectroscopy
JF  - Optics Express
Y1  - 2013
U6  - http://dx.doi.org/10.1364/OE.21.006764
SN  - 1094-4087
VL  - 21
IS  - 6
SP  - 6764
EP  - 6776
PB  - Optica
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Fleischhaker, Robert
A1  - Evers, Jörg
T1  - A Maxwell–Schrödinger solver for quantum optical few-level systems
JF  - Computer Physics Communications
N2  - The msprop program presented in this work is capable of solving the Maxwell–Schrödinger 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.
Y1  - 2011
U6  - http://dx.doi.org/10.1016/j.cpc.2010.10.018
SN  - 0010-4655
VL  - 182
IS  - 3
SP  - 739
EP  - 747
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Fleischhaker, Robert
A1  - Evers, Jörg
T1  - Nonlinear effects in pulse propagation through Doppler-broadened closed-loop atomic media
JF  - Physical Review A - Atomic, molecular, and optical physics
Y1  - 2008
U6  - http://dx.doi.org/10.1103/PhysRevA.77.043805
SN  - 1050-2947
VL  - 77
IS  - 4
SP  - 043805
ER  - 
TY  - JOUR
A1  - Mykoniou, Konstantin
A1  - Butenweg, Christoph
A1  - Holtschoppen, Britta
A1  - Klinkel, Sven
T1  - Seismic response analysis of adjacent liquid-storage tanks
JF  - Earthquake engineering and structural dynamics
N2  - 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.
KW  - liquid-structure interaction
KW  - seismic response
KW  - impulsive effects
KW  - liquid-storage tank
KW  - structure-soil-structure interaction
Y1  - 2016
U6  - http://dx.doi.org/10.1002/eqe.2726
SN  - 1096-9845 (E-Journal); 0098-8847 (Print)
VL  - 45
IS  - 11
SP  - 1779
EP  - 1796
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fleischhaker, Robert
A1  - Evers, Jörg
T1  - Four-wave mixing enhanced white-light cavity
JF  - Physical Review A - Atomic, molecular, and optical physics
Y1  - 2008
SN  - 0556-2791
VL  - 78
IS  - 5
SP  - 051802(R)
ER  - 
TY  - JOUR
A1  - Jablonowski, Nicolai David
A1  - Kollmann, Tobias
A1  - Nabel, Moritz
A1  - Damm, Tatjana
A1  - Klose, Holger
A1  - Müller, Michael
A1  - Bläsing, Marc
A1  - Seebold, Sören
A1  - Krafft, Simone
A1  - Kuperjans, Isabel
A1  - Dahmen, Markus
A1  - Schurr, Ulrich
T1  - Valorization of Sida (Sida hermaphrodita) biomass for multiple energy purposes
JF  - GCB [Global Change Biology] Bioenergy
N2  - 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.
Y1  - 2016
U6  - http://dx.doi.org/10.1111/gcbb.12346
SN  - 1757-1707 (online)
SN  - 1757-1693 (print)
N1  - Special Issue: Perennial biomass crops for a resource constrained world
VL  - 9
IS  - 1
SP  - 202
EP  - 214
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Alexopoulos, Spiros
A1  - Hoffschmidt, Bernhard
T1  - Advances in solar tower technology
JF  - Wiley interdisciplinary reviews : Energy and Environment : WIREs
Y1  - 2017
U6  - http://dx.doi.org/10.1002/wene.217
SN  - 2041-840X
VL  - 6
IS  - 1
SP  - 1
EP  - 19
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Srivastava, A.
A1  - Chahar, V.
A1  - Sharma, V.
A1  - Sun, Y.
A1  - Bol, R.
A1  - Knolle, F.
A1  - Schnug, E.
A1  - Hoyler, Friedrich
A1  - Naskar, N.
A1  - Lahiri, S.
A1  - Patnaik, R.
T1  - Study of uranium toxicity using low-background gamma-ray spectrometry
JF  - Journal of Radioanalytical and Nuclear Chemistry
Y1  - 2017
U6  - http://dx.doi.org/10.1007/s10967-017-5466-9
SN  - 1588-2780
IS  - Online first
SP  - 1
EP  - 7
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Rieke, Christian
A1  - Stollenwerk, Dominik
A1  - Dahmen, Markus
A1  - Pieper, Martin
T1  - Modeling and optimization of a biogas plant for a demand-driven energy supply
JF  - Energy
N2  - 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.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.energy.2017.12.073
SN  - 0360-5442
VL  - 145
SP  - 657
EP  - 664
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rupp, Matthias
A1  - Handschuh, Nils
A1  - Rieke, Christian
A1  - Kuperjans, Isabel
T1  - Contribution of country-specific electricity mix and charging time to environmental impact of battery electric vehicles: A case study of electric buses in Germany
JF  - Applied Energy
Y1  - 2019
U6  - http://dx.doi.org/10.1016/j.apenergy.2019.01.059
SN  - 0306-2619
VL  - 237
SP  - 618
EP  - 634
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dotzauer, Martin
A1  - Pfeiffer, Diana
A1  - Lauer, Markus
A1  - Pohl, Marcel
A1  - Mauky, Eric
A1  - Bär, Katharina
A1  - Sonnleitner, Matthias
A1  - Zörner, Wilfried
A1  - Hudde, Jessica
A1  - Schwarz, Björn
A1  - Faßauer, Burkhardt
A1  - Dahmen, Markus
A1  - Rieke, Christian
A1  - Herbert, Johannes
A1  - Thrän, Daniela
T1  - How to measure flexibility – Performance indicators for demand driven power generation from biogas plants
JF  - Renewable Energy
Y1  - 2019
U6  - http://dx.doi.org/10.1016/j.renene.2018.10.021
SN  - 0960-1481
SP  - 135
EP  - 146
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Keller, Johannes
A1  - Rath, Volker
A1  - Bruckmann, Johanna
A1  - Mottaghy, Darius
A1  - Clauser, Christoph
A1  - Wolf, Andreas
A1  - Seidler, Ralf
A1  - Bücker, H. Martin
A1  - Klitzsch, Norbert
T1  - SHEMAT-Suite: An open-source code for simulating flow, heat and species transport in porous media
JF  - SoftwareX
N2  - SHEMAT-Suite is a finite-difference open-source code for simulating coupled flow, heat and species transport in porous media. The code, written in Fortran-95, originates from geoscientific research in the fields of geothermics and hydrogeology. It comprises: (1) a versatile handling of input and output, (2) a modular framework for subsurface parameter modeling, (3) a multi-level OpenMP parallelization, (4) parameter estimation and data assimilation by stochastic approaches (Monte Carlo, Ensemble Kalman filter) and by deterministic Bayesian approaches based on automatic differentiation for calculating exact (truncation error-free) derivatives of the forward code.
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.softx.2020.100533
SN  - 2352-7110
VL  - 12
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Nobis, Moritz
A1  - Schmitt, Carlo
A1  - Schemm, Ralf
A1  - Schnettler, Armin
T1  - Pan-European CVAR-constrained stochastic unit commitment in day-ahead and intraday electricity markets
JF  - Energies
N2  - The fundamental modeling of energy systems through individual unit commitment decisions is crucial for energy system planning. However, current large-scale models are not capable of including uncertainties or even risk-averse behavior arising from forecasting errors of variable renewable energies. However, risks associated with uncertain forecasting errors have become increasingly relevant within the process of decarbonization. The intraday market serves to compensate for these forecasting errors. Thus, the uncertainty of forecasting errors results in uncertain intraday prices and quantities. Therefore, this paper proposes a two-stage risk-constrained stochastic optimization approach to fundamentally model unit commitment decisions facing an uncertain intraday market. By the nesting of Lagrangian relaxation and an extended Benders decomposition, this model can be applied to large-scale, e.g., pan-European, power systems. The approach is applied to scenarios for 2023—considering a full nuclear phase-out in Germany—and 2035—considering a full coal phase-out in Germany. First, the influence of the risk factors is evaluated. Furthermore, an evaluation of the market prices shows an increase in price levels as well as an increasing day-ahead-intraday spread in 2023 and in 2035. Finally, it is shown that intraday cross-border trading has a significant influence on trading volumes and prices and ensures a more efficient allocation of resources.
Y1  - 2020
U6  - http://dx.doi.org/10.3390/en13092339
SN  - 1996-1073
N1  - Special Issue Uncertainties and Risk Management in Competitive Energy Markets
VL  - 13
IS  - Art. 2339
SP  - 1
EP  - 35
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Sattler, Johannes, Christoph
A1  - Röger, Marc
A1  - Schwarzbözl, Peter
A1  - Buck, Reiner
A1  - Macke, Ansgar
A1  - Raeder, Christian
A1  - Göttsche, Joachim
T1  - Review of heliostat calibration and tracking control methods
JF  - Solar Energy
N2  - Large scale central receiver systems typically deploy between thousands to more than a hundred thousand heliostats. During solar operation, each heliostat is aligned individually in such a way that the overall surface normal bisects the angle between the sun’s position and the aim point coordinate on the receiver. Due to various tracking error sources, achieving accurate alignment ≤1 mrad for all the heliostats with respect to the aim points on the receiver without a calibration system can be regarded as unrealistic. Therefore, a calibration system is necessary not only to improve the aiming accuracy for achieving desired flux distributions but also to reduce or eliminate spillage. An overview of current larger-scale central receiver systems (CRS), tracking error sources and the basic requirements of an ideal calibration system is presented. Leading up to the main topic, a description of general and specific terms on the topics heliostat calibration and tracking control clarifies the terminology used in this work. Various figures illustrate the signal flows along various typical components as well as the corresponding monitoring or measuring devices that indicate or measure along the signal (or effect) chain. The numerous calibration systems are described in detail and classified in groups. Two tables allow the juxtaposition of the calibration methods for a better comparison. In an assessment, the advantages and disadvantages of individual calibration methods are presented.
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.solener.2020.06.030
VL  - 207
SP  - 110
EP  - 132
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hoffstadt, Kevin
A1  - Pohen, Gino D.
A1  - Dicke, Max D.
A1  - Paulsen, Svea
A1  - Krafft, Simone
A1  - Zang, Joachim W.
A1  - Fonseca-Zang, Warde A. da
A1  - Leite, Athaydes
A1  - Kuperjans, Isabel
T1  - Challenges and prospects of biogas from energy cane as supplement to bioethanol production
JF  - Agronomy
N2  - Innovative breeds of sugar cane yield up to 2.5 times as much organic matter as conventional breeds, resulting in a great potential for biogas production. The use of biogas production as a complementary solution to conventional and second-generation ethanol production in Brazil may increase the energy produced per hectare in the sugarcane sector. Herein, it was demonstrated that through ensiling, energy cane can be conserved for six months; the stored cane can then be fed into a continuous biogas process. This approach is necessary to achieve year-round biogas production at an industrial scale. Batch tests revealed specific biogas potentials between 400 and 600 LN/kgVS for both the ensiled and non-ensiled energy cane, and the specific biogas potential of a continuous biogas process fed with ensiled energy cane was in the same range. Peak biogas losses through ensiling of up to 27% after six months were observed. Finally, compared with second-generation ethanol production using energy cane, the results indicated that biogas production from energy cane may lead to higher energy yields per hectare, with an average energy yield of up to 162 MWh/ha. Finally, the Farm²CBG concept is introduced, showing an approach for decentralized biogas production.
Y1  - 2020
U6  - http://dx.doi.org/10.3390/agronomy10060821
SN  - 2073-4395
VL  - 10
IS  - 6
PB  - MDPI
CY  - Basel
ER  -