TY - JOUR A1 - Förster, Arnold A1 - Appenzeller, J. A1 - Schroer, C. T1 - Electron interference in a T-shaped quantum transistor based on Schottky-gate technology / J. Appenzeller ; Ch. Schroer ; Th. Schäpers ... A. Förster ... JF - Physical review / B, Condensed matter and materials physics. 53 (1996), H. 15 Y1 - 1996 SN - 1095-3795 SP - 9959 EP - 9963 ER - TY - JOUR A1 - Förster, Arnold A1 - Betko, J. A1 - Kordos, P. A1 - Kuklovsky, S. T1 - Electrical properties of molecular beam epitaxial GaAs layers grown at low temperature / J. Betko ; P. Kordos ; S. Kuklovsky ; A. Förster ... JF - Materials science and engineering B: Solid– state materials for advanced technology. 28 (1994), H. 1-3 Y1 - 1994 SN - 0921-5107 SP - 147 EP - 150 ER - TY - JOUR A1 - Förster, Arnold A1 - Kordos, P. A1 - Betko, J. T1 - Electrical and structural characterization of MBE GaAs grown at temperatures between 200 and 600 °C / P. Kordos ; J. Betko; A. Förster ... JF - Compound semiconductors, 1994 : proceedings of the twenty-first International Symposium on Compound Semiconductors held in San Diego, California, 18 - 22 September, 1994 / ed. by Herb Goronkin ... - (Conference series / Institute of Physics ; 141) Y1 - 1995 SN - 0-7503-0226-7 N1 - International Symposium on Compound Semiconductors <21, 1994, San Diego, Calif.> ; Institute of Physics SP - 295 EP - ff. PB - Institute of Physics CY - Bristol [u.a.] ER - TY - JOUR A1 - Förster, Arnold A1 - Lange, J. A1 - Gerthsen, D. T1 - Effect of interface roughness and scattering on the performance of AlAs/InGaAs resonant tunneling diodes JF - Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 11 (1993), H. 4 Y1 - 1993 SN - 1071-1023 N1 - ISSN der E-Ausg.: 0734-211X SP - 1743 EP - 1747 ER - TY - JOUR A1 - Förster, Arnold A1 - Schäpers, T. A1 - Krüger, M. A1 - Appenzeller, J. T1 - Effect of electron-electron interaction on hot ballistic electron beams / Th. Schäpers ; M. Krüger ; J. Appenzeller ; A. Förster ... JF - Applied physics letters. 66 (1995), H. 26 Y1 - 1995 SN - 0003-6951 N1 - ISSN der E-Ausg.: 1077-3118 SP - 3603 EP - 3606 ER - TY - JOUR A1 - Rupp, Matthias A1 - Rieke, Christian A1 - Handschuh, Nils A1 - Kuperjans, Isabel T1 - Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities JF - Transportation Research Part D: Transport and Environment N2 - 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. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.trd.2020.102293 SN - 1361-9209 VL - 81 IS - Article 102293 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hoyler, Friedrich A1 - Colvin, G. G. A1 - Robinson, S. J. T1 - E0 transitions in 106Pd studied by neutron capture / G. G. Colvin ; F. Hoyler ; S. J. Robinson JF - Journal of physics / G. 13 (1987), H. 2 Y1 - 1987 SN - 0305-4616 SP - 191 EP - 204 ER - TY - JOUR A1 - Förster, Arnold A1 - Leuther, A. A1 - Lüth, H. T1 - DX centres, conduction band offsets and Si-dopant segregation in heterostructures / A. Leuther ; A. Förster ; H. Lüth ... JF - Semiconductor science and technology. 11 (1996), H. 5 Y1 - 1996 SN - 1361-6641 SP - 766 EP - 771 ER - TY - JOUR A1 - Förster, Arnold A1 - Hauke, M. A1 - Jakumeit, J. A1 - Krafft, B. T1 - DX Centers in Al0.3Ga0.7As/GaAs Analyzed by Point Contact Measurements. Hauke, M.; Jakumeit, J.; Krafft, B.; Nimtz, G.; Förster, A.; Lüth, H. JF - Journal of Applied Physics. 84 (1998), H. 4 Y1 - 1998 SN - 1089-7550 SP - 2034 EP - 2039 ER - TY - JOUR A1 - Steuer-Dankert, Linda A1 - Sharma, Mamta Rameshwarlal A1 - Bleck, Wolfgang A1 - Leicht-Scholten, Carmen T1 - Diversity and innovation management in large research groups JF - International Journal of Innovation Management N2 - Contemporary research appreciates a diverse workforce as a potential source of innovation. Researchers explore the fine details of why diversity management is central for generating innovations in heterogeneous research groups and how it could be effectively implemented into organizations. Complex research associations that discuss topics with a high impact on society increasingly address the necessity of establishing a diverse workforce to confront the challenges of tomorrow. Characterized by complex management structures as well as hierarchies, research associations have not been a subject of investigation until now. For this reason, the presented research project aims to develop a diversity and innovation management strategy with the ultimate goal of inducing change in the corporate culture. The proposed approach consisted of six phases; the first two phases investigated the status quo of diversity in the existing organizational structures of member institutes and the variety of particular working cultures within the research association. The third and the fourth phases utilized qualitative and quantitative studies. The third phase focused on the connection of management level to diversity and innovation, and the need for diversity and innovation management, and tailor-made methods of implementing them. The first three phases have been accomplished successfully; preliminary results are already available. The fourth phase will mainly focus on exploring the mind-set of the employees. The fifth phase will consolidate the findings in the first four phases into an implementable strategy. The final phase will address the implementation of this strategy into the organization. Phases 4 to 6 have not yet been undertaken KW - diversity management KW - innovation management KW - research association KW - change management KW - engineering Y1 - 2017 SN - 1757-5877 VL - 5 IS - 2 SP - 49 EP - 72 ER - 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 -