TY  - JOUR
A1  - Schwarzer, Klemens
A1  - Krings, T.
T1  - Dissemination of solar cookers with and without temporary storage : a report of concrete examples ; experiences from Chile, India and Mali
JF  - Proceedings / EuroSun '96 : 10. Internationales Sonnenforum. Ed. by A. Goetzberger ... - Bd. 4
Y1  - 1996
N1  - EuroSun <1, 1996, Freiburg, Breisgau>
SP  - 1479
EP  - 1482
PB  - DGS-Sonnenenergie-Verl.
CY  - München
ER  - 
TY  - JOUR
A1  - Schüller-Ruhl, Aaron
A1  - Dinstühler, Leonard
A1  - Senger, Thorsten
A1  - Bergfeld, Stefan
A1  - Ingenhag, Christian
A1  - Fleischhaker, Robert
ED  - Mackenzie, Jacob
T1  - Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications
JF  - Applied Physics B
N2  - We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg–Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10−3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements.
Y1  - 2022
U6  - http://dx.doi.org/10.1007/s00340-022-07928-2
SN  - 1432-0649 (Online)
SN  - 0946-2171 (Print)
N1  - Corresponding author: Robert Fleischhaker
VL  - 128
IS  - Article number: 208
SP  - 1
EP  - 11
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Edip, K.
A1  - Sesov, V.
A1  - Butenweg, Christoph
A1  - Bojadjieva, J.
T1  - Development of coupled numerical model for simulation of multiphase soil
JF  - Computers and Geotechnics
N2  - 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.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.compgeo.2017.08.016
SN  - 0266-352X
VL  - 96
SP  - 118
EP  - 131
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hoffschmidt, Bernhard
A1  - Fernandez, V.
A1  - Konstandopoulus, A. G.
T1  - Development of ceramic volumetric receiver technology
JF  - Forschungsbericht : DLR FB. 10 (2001)
Y1  - 2001
SN  - 0939-2963
N1  - 2. ISSN: 1434-8454 ; Kölner Sonnenkolloquium <5, 2001, Köln> ; Solar thermal power plants and solar chemical processes : advances and perspectives for international cooperation
SP  - 51
EP  - 61
ER  - 
TY  - JOUR
A1  - Arpshofen, Ingo
A1  - Pool, M. J.
A1  - Sommer, Ferdinand
A1  - Gerling, Ulrich
A1  - Predel, Bruno
A1  - Schultheiss, Emil
T1  - Determination of the integral mixing enthalpies in the Cu-Pd-Si liquid ternary alloy system at 1600 K
JF  - Zeitschrift für Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 1
Y1  - 1983
SN  - 0044-3093 ; 0179-4841
SP  - 25
EP  - 32
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Krumbe, Christoph
A1  - Schumacher, Katharina
A1  - Groebel, Simone
A1  - Spelthahn, Heiko
A1  - Stellberg, Michael
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli by a light-addressable potentiometric sensor
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1340
EP  - 1344
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Helsper, Christoph
A1  - Wiedensohler, A.
A1  - Weise, W.
A1  - Lütkemeier, E.
T1  - Determination of the Bipolar Charge Equilibrium in Pure Gases / Wiedensohler, A. ; Weise, W. ; Helsper, C. ; Lütkemeier, E.
JF  - Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft für Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)
Y1  - 1986
N1  - International Aerosol Conference ; (2, 1986, Berlin (West))
SP  - 383
EP  - 386
PB  - Pergamon Press
CY  - Oxford [u.a.]
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Tillmann, K.
A1  - Thust, M.
T1  - Determination of segregation, elastic strain and thin-foil relaxation in InxGa-1-x As islands on GaAs(001) by high resolution transmission electron microscopy / K. Tillmann ; A. Thust ; M. Lentzen ... A. Förster ...
JF  - Philosophical magazine / Letters. 74 (1996), H. 5
Y1  - 1996
SN  - 1362-3036
SP  - 309
EP  - 315
ER  - 
TY  - JOUR
A1  - Helsper, Christoph
A1  - Fißan, H. J.
A1  - Thielen, H. J.
T1  - Determination of Particle Size Distributions by Means of an Electrostatic Classifier / Fißan, H. J.; Helsper, C. ; Thielen, H. J.
JF  - Journal of Aerosol Science. 14 (1983), H. 3
Y1  - 1983
SN  - 0021-8502
SP  - 354
EP  - 357
ER  - 
TY  - JOUR
A1  - Rochefort, E. de
A1  - Verver, M.
A1  - Grunendahl, A.
A1  - Mooi, H.
A1  - Butenweg, Christoph
T1  - Detailed modelling of the lumbar spine for investigations of low back pain
JF  - SAE transactions : papers presented at Society and Section meetings / Society of Automotive Engineers
Y1  - 2005
SN  - 0096-736X
VL  - Volume 114
IS  - Part 7
SP  - 788
EP  - 796
ER  - 
TY  - JOUR
A1  - Kürten, Sylvia
A1  - Mottaghy, Darius
A1  - Ziegler, Martin
T1  - Design of plane energy geostructures based on laboratory tests and numerical modelling
JF  - Energy and Buildings
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.enbuild.2015.08.039
SN  - 0378-7788
VL  - 107
SP  - 434
EP  - 444
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hoffstadt, Kevin
A1  - Cheenakula, Dheeraja
A1  - Nikolausz, Marcell
A1  - Krafft, Simone
A1  - Harms, Hauke
A1  - Kuperjans, Isabel
T1  - Design and construction of a new reactor for flexible biomethanation of hydrogen
JF  - Fermentation
N2  - The increasing share of renewable electricity in the grid drives the need for sufficient storage capacity. Especially for seasonal storage, power-to-gas can be a promising approach. Biologically produced methane from hydrogen produced from surplus electricity can be used to substitute natural gas in the existing infrastructure. Current reactor types are not or are poorly optimized for flexible methanation. Therefore, this work proposes a new reactor type with a plug flow reactor (PFR) design. Simulations in COMSOL Multiphysics ® showed promising properties for operation in laminar flow. An experiment was conducted to support the simulation results and to determine the gas fraction of the novel reactor, which was measured to be 29%. Based on these simulations and experimental results, the reactor was constructed as a 14 m long, 50 mm diameter tube with a meandering orientation. Data processing was established, and a step experiment was performed. In addition, a kLa of 1 h−1 was determined. The results revealed that the experimental outcomes of the type of flow and gas fractions are in line with the theoretical simulation. The new design shows promising properties for flexible methanation and will be tested.
KW  - methanation
KW  - plug flow reactor
KW  - bubble column
KW  - bio-methane
KW  - power-to-gas
Y1  - 2023
U6  - http://dx.doi.org/10.3390/fermentation9080774
SN  - 2311-5637
N1  - The article belongs to the Special Issue Fermentation Processes: Modeling, Optimization and Control
VL  - 9
IS  - 8
SP  - 1
EP  - 16
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Rose, D.
A1  - Pietsch, U.
A1  - Metzger, T. H.
T1  - Depth resolved investigations of the relaxation behaviour in strained GaInAs/GaAs superlattices using grazing incidence X-ray diffraction / Rose, D. ; Pietsch, U. ; Förster, A. ; Metzger, T. H.
JF  - Nuclear instruments and methods in physics research / Section B, Beam interactions with materials and atoms. 97 (1995), H. 1-4
Y1  - 1995
SN  - 0168-583X
SP  - 333
EP  - 336
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Rose, D.
A1  - Pietsch, U.
A1  - Metzger, H.
T1  - Depth resolved investigation of the relaxation behaviour in strained GaInAs/GaAs superlattices / Rose, D. ; Pietsch, U. ; Förster, A. ; Metzger, H....
JF  - Physica B: condensed matter. 198 (1994), H. 1-3
Y1  - 1994
SN  - 0921-4526
SP  - 256
EP  - 258
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Indlekofer, K.M.
A1  - Lüth, H.
T1  - Density-matrix description of a quantum dot system with variable lateral confinement in the single-electron tunneling regime. Indlekofer, K.M.; Förster, A.; Lüth, H.
JF  - Physica B: Condensed Matter. 314 (2002), H. 1-4
Y1  - 2002
SN  - 0921-4526
SP  - 499
EP  - 502
ER  - 
TY  - JOUR
A1  - Breitbach, Gerd
A1  - Schmidt-Plutka, A.
A1  - Schubert, F.
A1  - Nickel, H.
T1  - Deformation behaviour of structures exposed at very high temperatures to cyclic thermal and mechanical loadings
JF  - Structural mechanics in reactor technology : transactions of the 12th International Conference on Structural Mechanics in Reactor Technology, Stuttgart, Germany, 15-20 August 1993 / ed. Karl F. Kussmaul. - Bd. L : Inelastic behaviour of solids and structures
Y1  - 1993
SN  - 0-444-81515-5
N1  - SMiRT <12, 1993, Stuttgart>  ; L08/3
SP  - 203
EP  - 208
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Darmo, J.
A1  - Dubecký, F.
A1  - Kordos, P.
T1  - Deep-level states and electrical properties of GaAs grown at 250 °C / J. Darmo ; F. Dubecký ; P. Kordos ; A. Förster ...
JF  - Materials science and engineering B: Solid&#150; state materials for advanced technology. 28 (1994), H. 1-3
Y1  - 1994
SN  - 0921-5107
SP  - 393
EP  - 396
ER  - 
TY  - JOUR
A1  - Helsper, Christoph
A1  - Fißan, H. J.
A1  - Kapadi, A.
A1  - Liu, B. Y. H.
T1  - Data Inversion by Simplex Minimization for the Electrical Aerosol Analyzer
JF  - Aerosol Science and Technology. 1 (1982), H. 1982
Y1  - 1982
SN  - 0278-6826
SP  - 136
EP  - 146
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Verghese, S.
A1  - Zamdmer, N.
A1  - Hu, Qing
T1  - Cryogenic picosecond sampling using fiber-coupled photoconductive switch / S. Verghese ; N. Zamdmer ; Qing Hu ; A. Förster
JF  - Applied physics letters. 70 (1997), H. 20
Y1  - 1997
SN  - 0003-6951
N1  - ISSN der E-Ausg.: 1077-3118
SP  - 2644
EP  - 2646
ER  - 
TY  - JOUR
A1  - Tillmann, K.
A1  - Förster, Arnold
T1  - Critical dimensions for the formation of interfacial misfit dislocations of In0.6Ga0.4As islands on GaAs(001)
JF  - Thin Solid Films. 368 (2000), H. 1
Y1  - 2000
SN  - 0040-6090
SP  - 93
EP  - 104
ER  -