TY - JOUR A1 - Förster, Arnold A1 - Schäfer, B.-J. A1 - Londschien, M. T1 - Arsenic passivation of MOMBE grown GaAs surfaces / B. -J. Schäfer ; A. Förster ; M. Londschien ... JF - Surface Science. 204 (1988), H. 3 Y1 - 1988 SN - 0039-6028 N1 - ISSN der E-Ausg.: 0039-6028 SP - 485 EP - 490 ER - TY - JOUR A1 - Förster, Arnold A1 - Resch, U. A1 - Essera, N. A1 - Raptis, Y. S. T1 - Arsenic passivation of MBE grown GaAs(100): structural and electronic properties of the decapped surfaces / U. Resch ; N. Essera ; Y. S. Raptis ... A. Förster ... JF - Surface Science. 269-270 (1992) Y1 - 1992 SN - 0039-6028 N1 - ISSN der E-Ausg.: 0039-6028 SP - 797 EP - 803 ER - TY - JOUR A1 - Pieper, Martin A1 - Klein, Peter T1 - Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media JF - Heat mass transfer N2 - Often, detailed simulations of heat conduction in complicated, porous media have large runtimes. Then homogenization is a powerful tool to speed up the calculations by preserving accurate solutions at the same time. Unfortunately real structures are generally non-periodic, which requires unpractical, complicated homogenization techniques. We demonstrate in this paper, that the application of simple, periodic techniques to realistic media, that are just close to periodic, gives accurate, approximative solutions. In order to obtain effective parameters for the homogenized heat equation, we have to solve a so called “cell problem”. In contrast to periodic structures it is not trivial to determine a suitable unit cell, which represents a non-periodic media. To overcome this problem, we give a rule of thumb on how to choose a good cell. Finally we demonstrate the efficiency of our method for virtually generated foams as well as real foams and compare these results to periodic structures. Y1 - 2012 U6 - http://dx.doi.org/10.1007/s00231-011-0879-4 SN - 0947-7411 VL - 48 IS - 2 SP - 291 EP - 300 PB - Springer CY - Berlin ER - TY - JOUR A1 - Helsper, Christoph A1 - Nießner, R. A1 - Rönicke, G. T1 - Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R.; Helsper, C.; Rönicke, G. JF - Aerosols : science, technology, and industr. applications of airborne particles ; proceedings of the 1. Internat. Aerosol Conference held Sept. 17-21, 1984, Minneapolis, Minn., U.S.A / ed.: Benjamin Y. H. Liu Y1 - 1984 SN - 0444009477 N1 - International Aerosol Conference ; (1, 1984, Minneapolis, Minn.) SP - 63 EP - 66 PB - Elsevier CY - New York [u.a.] ER - TY - JOUR A1 - Helsper, Christoph A1 - Nießner, R. T1 - Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R. ; Helsper, C. JF - Journal of Aerosol Science. 16 (1985), H. 3 Y1 - 1985 SN - 0021-8502 SP - 201 EP - 209 ER - TY - JOUR A1 - Schwarzer, Klemens T1 - Anwendung solarer Hochtemperaturwärme am Beispiel eines Solarkochers JF - Wege in die Solargesellschaft 4 : Dokumentation zur Vortragsreihe an der Fachhochschule Darmstadt in Zusammenarbeit mit dem IKU-Institut für kommunale Wirtschaft und Umweltplanung im Sommersemester 1993 / [Hrsg.: Projektgruppe Solarenergie an der Fachhochschule Darmstadt ; IKU-Inst. für Kommunale Wirtschaft u. Umweltplanung. Red.: Helmut C. Büscher] Y1 - 1993 N1 - Ringvorlesung Wege in die Solargesellschaft <4, 1993, Darmstadt> SP - 13 EP - 24 PB - FHD CY - Darmstadt ER - TY - JOUR A1 - Breitbach, Gerd A1 - Altes, J. A1 - Szimmat, J. T1 - Anwendung der Finite-Element-Methode bei der Berechnung des Wärmetransports durch Strahlung / J. Altes ; G. Breitbach ; J. Szimmat JF - International FEM-Congress : Baden-Baden, Federal Republic of Germany, 17./18. November 1986 Y1 - 1989 N1 - International FEM Congress <15, 1986, Baden-Baden> SP - 127 EP - 148 PB - IKO Software Service GmbH CY - Stuttgart ER - TY - JOUR A1 - Förster, Arnold A1 - Darmo, J. A1 - Dubecky, F. A1 - Kordos, P. T1 - Annealing effect on concentration of EL6-like deep-level state in low-temperature-grown molecular beam epitaxial GaAs. Darmo, J.; Dubecky, F.; Kordos, P.; Förster, A. JF - Applied Physics Letters. 72 (1998), H. 5 Y1 - 1998 SN - 1077-3118 SP - 590 EP - 592 ER - TY - JOUR A1 - Förster, Arnold A1 - Darmo, J. A1 - Dubecký, F. A1 - Kordos, P. T1 - Annealing characteristics of native defects in low-temperature-grown MBE GaAs / J. Darmo ; F. Dubecky ; P. Kordos ; A. Förster JF - Semiconducting and insulating materials 1996 : proceedings of the 9th Conference on Semiconducting and Insulating Materials (SIMC '9), April 29 - May 3, 1996, Toulouse, France / [IEEE] Y1 - 1996 SN - 0-7803-3095-1 N1 - 2. ISBN: 0-7803-3179-6 ; Conference on Semiconducting and Insulating Materials <9, 1996, Toulouse> ; Institute of Electrical and Electronics Engineers ; IEEE Cat. No.96CH35881 SP - 67 EP - ff. CY - Piscataway, NJ [u.a.] ER - TY - JOUR A1 - Kern, Alexander A1 - Zischank, Wolfgang A1 - Beierl, Ottmar T1 - Anmerkungen zur Berechnung des Trennungsabstands nach DIN EN 62305-3 (VDE 0185-305-3): 2006-10 / Zischank, Wolfgang ; Beierl, Ottmar ; Kern, Alexander JF - 7. VDE-ABB-Blitzschutztagung : Vorträge der VDE-ABB-Fachtagung vom 15. bis 16. November 2007 in Neu-Ulm / Veranst.: Ausschuss für Blitzschutz und Blitzforschung (ABB) im VDE, Verband der Elektrotechnik, Elektronik, Informationstechnik e.V. Wiss. Tagungsltg.: K. Stimper Y1 - 2007 SN - 978-3-8007-3062-9 N1 - VDE-Fachbericht ; 64 ; Blitzschutztagung <7, 2007, Neu-Ulm> SP - 1 EP - 8 PB - VDE-Verl. CY - Berlin ER - TY - JOUR A1 - Barsov, S. A1 - Bechstedt, U. A1 - Hardt, Arno T1 - ANKE, a new facility for medium energy hadron physics at COSY-Jülich / S. Barsov [u.a.] JF - Nuclear instruments and methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Vol. 462, iss. 3 Y1 - 2001 SN - 0167-5087 (Print) ; 0168-9002 (E-journal) SP - 364 EP - 381 ER - TY - JOUR A1 - Butenweg, Christoph A1 - Rosin, Julia A1 - Holler, Stefan T1 - Analysis of cylindrical granular material silos under seismic excitation JF - Buildings N2 - Silos generally work as storage structures between supply and demand for various goods, and their structural safety has long been of interest to the civil engineering profession. This is especially true for dynamically loaded silos, e.g., in case of seismic excitation. Particularly thin-walled cylindrical silos are highly vulnerable to seismic induced pressures, which can cause critical buckling phenomena of the silo shell. The analysis of silos can be carried out in two different ways. In the first, the seismic loading is modeled through statically equivalent loads acting on the shell. Alternatively, a time history analysis might be carried out, in which nonlinear phenomena due to the filling as well as the interaction between the shell and the granular material are taken into account. The paper presents a comparison of these approaches. The model used for the nonlinear time history analysis considers the granular material by means of the intergranular strain approach for hypoplasticity theory. The interaction effects between the granular material and the shell is represented by contact elements. Additionally, soil–structure interaction effects are taken into account. KW - granular silo KW - earthquake engineering KW - hypoplasticity KW - nonlinear transient analyses Y1 - 2017 U6 - http://dx.doi.org/10.3390/buildings7030061 SN - 2075-5309 VL - 7 IS - 3 SP - 1 EP - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Maurer, Florian A1 - Rieke, Christian A1 - Schemm, Ralf A1 - Stollenwerk, Dominik T1 - Analysis of an urban grid with high photovoltaic and e-mobility penetration JF - Energies N2 - This study analyses the expected utilization of an urban distribution grid under high penetration of photovoltaic and e-mobility with charging infrastructure on a residential level. The grid utilization and the corresponding power flow are evaluated, while varying the control strategies and photovoltaic installed capacity in different scenarios. Four scenarios are used to analyze the impact of e-mobility. The individual mobility demand is modelled based on the largest German studies on mobility “Mobilität in Deutschland”, which is carried out every 5 years. To estimate the ramp-up of photovoltaic generation, a potential analysis of the roof surfaces in the supply area is carried out via an evaluation of an open solar potential study. The photovoltaic feed-in time series is derived individually for each installed system in a resolution of 15 min. The residential consumption is estimated using historical smart meter data, which are collected in London between 2012 and 2014. For a realistic charging demand, each residential household decides daily on the state of charge if their vehicle requires to be charged. The resulting charging time series depends on the underlying behavior scenario. Market prices and mobility demand are therefore used as scenario input parameters for a utility function based on the current state of charge to model individual behavior. The aggregated electricity demand is the starting point of the power flow calculation. The evaluation is carried out for an urban region with approximately 3100 residents. The analysis shows that increased penetration of photovoltaics combined with a flexible and adaptive charging strategy can maximize PV usage and reduce the need for congestion-related intervention by the grid operator by reducing the amount of kWh charged from the grid by 30% which reduces the average price of a charged kWh by 35% to 14 ct/kWh from 21.8 ct/kWh without PV optimization. The resulting grid congestions are managed by implementing an intelligent price or control signal. The analysis took place using data from a real German grid with 10 subgrids. The entire software can be adapted for the analysis of different distribution grids and is publicly available as an open-source software library on GitHub. KW - distribution grid simulation KW - smart-charging KW - e-mobility Y1 - 2023 U6 - http://dx.doi.org/10.3390/en16083380 SN - 1996-1073 N1 - This article belongs to the Special Issue "Advanced Solutions for the Efficient Integration of Electric Vehicles in Electricity Grids" N1 - Corresponding author: Florian Maurer VL - 16 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kuperjans, Isabel A1 - Starke, M. A1 - Esser, J. A1 - [u.a.], T1 - Analyse und Konzeption von Energieanlagen unter ökologischen, wirtschaftlichen und technischen Gesichtspunkten JF - WLB : Umwelttechnik für Industrie und Kommune Y1 - 2000 SN - 0341-2679 VL - 44 IS - 11/12 SP - 26 EP - 29 ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Reinecke, Diana A1 - Klose, Holger A1 - Kuperjans, Isabel A1 - Grömping, Markus T1 - Anaerobic digestion of algal–bacterial biomass of an Algal Turf Scrubber system JF - Biomass Conversion and Biorefinery N2 - This study investigated the anaerobic digestion of an algal–bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal–bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4%) and a mixture of manure and maize silage (107.4%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6%) and percolated green waste (43.5%) inocula. To further evaluate the potential of algal–bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7–12.5 MWh a−1) can be gained through the addition of algal–bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies. KW - Biogas KW - Methane KW - Algal Turf Scrubber KW - Algal–bacterial bioflm KW - Circular bioeconomy Y1 - 2022 U6 - http://dx.doi.org/10.1007/s13399-022-03236-z SN - 2190-6823 N1 - Corresponding author: Dheeraja Cheenakula VL - 13 SP - 15 Seiten PB - Springer CY - Berlin ER - TY - JOUR A1 - Förster, Arnold A1 - Verghese, S. A1 - Zamdmer, N. A1 - Hu, Qing T1 - An optical correlator using a low-temperature-grown GaAs photoconductor / S. Verghese ; N. Zamdmer ; Qing Hu .... A. Förster JF - Applied physics letters. 69 (1996), H. 6 Y1 - 1996 SN - 0003-6951 N1 - ISSN der E-Ausg.: 1077-3118 SP - 842 EP - 844 ER - TY - JOUR A1 - Förster, Arnold A1 - Marso, M. A1 - Gersdorf, P. A1 - Fox, A. T1 - An InAlAs-InGaAs OPFET with responsivity above 200 A/W at 1.3-μm wavelength. Marso, M.; Gersdorf, P.; Fox, A.; Hodel, U.; Lambertini, R.; Kordos, P. JF - IEEE Photonics Technology Letters. 11 (1999), H. 1 Y1 - 1999 SN - 1041-1135 SP - 117 EP - 119 ER - TY - JOUR A1 - Lück, Reinhard A1 - Gerling, Ulrich A1 - Predel, Bruno T1 - An entropy paradox of the association model JF - Zeitschrift für Metallkunde : international journal of materials research and advanced techniques. Bd. 80, H. 4 Y1 - 1989 SN - 0044-3093 ; 0179-4841 SP - 270 EP - 275 ER - TY - JOUR A1 - Fischer, W. A. A1 - Dören, Horst-Peter A1 - Janke, Dieter T1 - Aluminium nitride probes for application in iron melts JF - Archiv für das Eisenhüttenwesen. 52 (1981), H. 3 Y1 - 1981 SN - 0003-8962 SP - 91 EP - 98 ER - TY - JOUR A1 - Hoyler, Friedrich A1 - Mohr, P. A1 - Staudt, G. T1 - Alpha-cluster states of 212po in a realistic potential model JF - Physical review / C. 50 (1994), H. 5 Y1 - 1994 SN - 0556-2813 SP - 2631 EP - 2634 ER -