TY - JOUR A1 - Holtrup, S. A1 - Sadeghfam, Arash A1 - Heuermann, Holger A1 - Awakowicz, P. T1 - Characterization and optimization technique for microwave-driven high-intensity discharge lamps using hot S-parameters JF - IEEE transactions on microwave theories and techniques N2 - High-intensity discharge lamps can be driven by radio-frequency signals in the ISM frequency band at 2.45 GHz, using a matching network to transform the impedance of the plasma to the source impedance. To achieve an optimal operating condition, a good characterization of the lamp in terms of radio frequency equivalent circuits under operating conditions is necessary, enabling the design of an efficient matching network. This paper presents the characterization technique for such lamps and presents the design of the required matching network. For the characterization, a high-intensity discharge lamp was driven by a monofrequent large signal at 2.45 GHz, whereas a frequency sweep over 300 MHz was performed across this signal to measure so-called small-signal hot S-parameters using a vector network analyzer. These parameters are then used as an equivalent load in a circuit simulator to design an appropriate matching network. Using the measured data as a black-box model in the simulation results in a quick and efficient method to simulate and design efficient matching networks in spite of the complex plasma behavior. Furthermore, photometric analysis of high-intensity discharge lamps are carried out, comparing microwave operation to conventional operation. Y1 - 2014 U6 - https://doi.org/10.1109/TMTT.2014.2342652 SN - 0018-9480 VL - 62 IS - 10 SP - 2471 EP - 2480 PB - IEEE CY - New York ER - TY - CHAP A1 - Holler, S. A1 - Butenweg, Christoph A1 - Noh, S.-Y. A1 - Meskouris, Konstantin T1 - Numerical simulation of textile-reinforced concrete structures T2 - Proceedings of the Sixth International Conference on Computational Structures Technology : [Prague, Czech Republic, 4 - 6 September 2002] / ed. by B. H. V. Topping and Z. Bittnar. (Civil-Comp Press books on computational engineering) Y1 - 2002 SN - 0-948749-83-0 SP - 287 EP - 288 PB - Civil-Comp Press CY - Stirling 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 - https://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 - CHAP A1 - Hofmann, Till A1 - Mataré, Victor A1 - Schiffer, Stefan A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - Constraint-based online transformation of abstract plans into executable robot actions T2 - Proceedings of the 2018 AAAI Spring Symposium on Integrating Representation, Reasoning, Learning, and Execution for Goal Directed Autonomy Y1 - 2018 SP - 549 EP - 553 ER - TY - CHAP A1 - Hofmann, Till A1 - Mataré, Victor A1 - Neumann, Tobias A1 - Schönitz, Sebastian A1 - Henke, Christoph A1 - Limpert, Nicolas A1 - Niemueller, Tim A1 - Ferrein, Alexander A1 - Jeschke, Sabina A1 - Lakemeyer, Gerhard T1 - Enhancing Software and Hardware Reliability for a Successful Participation in the RoboCup Logistics League 2017 Y1 - 2018 SN - 978-3-030-00308-1 U6 - https://doi.org/10.1007/978-3-030-00308-1_40 N1 - Lecture Notes in Computer Science, vol 11175 SP - 486 EP - 497 PB - Springer CY - Cham ER - TY - JOUR A1 - Hofmann, Till A1 - Limpert, Nicolas A1 - Mataré, Victor A1 - Schönitz, Sebastian A1 - Niemueller, Tim A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - The Carologistics RoboCup Logistics Team 2018 N2 - The Carologistics team participates in the RoboCup Logistics League for the seventh year. The RCLL requires precise vision, manipulation and path planning, as well as complex high-level decision making and multi-robot coordination. We outline our approach with an emphasis on recent modifications to those components. The team members in 2018 are David Bosen, Christoph Gollok, Mostafa Gomaa, Daniel Habering, Till Hofmann, Nicolas Limpert, Sebastian Schönitz, Morian Sonnet, Carsten Stoffels, and Tarik Viehmann. This paper is based on the last year’s team description. Y1 - 2018 ER - TY - CHAP A1 - Hofmann, Till A1 - Limpert, Nicolas A1 - Mataré, Victor A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - Winning the RoboCup Logistics League with Fast Navigation, Precise Manipulation, and Robust Goal Reasoning T2 - RoboCup 2019: Robot World Cup XXIII. RoboCup Y1 - 2019 SN - 978-3-030-35699-6 U6 - https://doi.org/10.1007/978-3-030-35699-6_41 N1 - Lecture Notes in Computer Science, vol 11531 SP - 504 EP - 516 PB - Springer CY - Cham 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 - https://doi.org/10.3390/agronomy10060821 SN - 2073-4395 VL - 10 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hoffstadt, Kevin A1 - Nikolausz, Marcell A1 - Krafft, Simone A1 - Bonatelli, Maria A1 - Kumar, Vivekanantha A1 - Harms, Hauke A1 - Kuperjans, Isabel T1 - Optimization of the ex situ biomethanation of hydrogen and carbon dioxide in a novel meandering plug flow reactor: start-up phase and flexible operation JF - Bioengineering KW - methanation KW - plug flow reactor KW - bubble column KW - biomethane KW - P2G Y1 - 2024 U6 - https://doi.org/10.3390/bioengineering11020165 SN - 2306-5354 VL - 11 IS - 2 PB - MDPI CY - Basel 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 - https://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 - Hoffschmidt, Bernhard A1 - Téllez, Félix M. A1 - Valverde, Antonio A1 - Fernandez, Valerio A1 - Fernandez, Jesus T1 - Performance evaluation of the 200-kWth HiTRec-II open volumetric air receiver JF - Journal of solar energy engineering Y1 - 2003 VL - Vol. 125 IS - Iss. 1 SP - 87 EP - 94 ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Telle, R. A1 - Sauerborn, Markus A1 - Wagner, M. T1 - Optical measurement system for high temperature absorbers T2 - SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain Y1 - 2011 CY - Granada ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Schwarzer, Klemens A1 - Späte, Frank A1 - Kötter, Jens A1 - Ebert, Miriam A1 - Sierck, Olaf T1 - Development of a small modular parabolic trough collector T2 - 13th International Symposium Concentrated Solar Power and Chemical Energy Technologies : SolarPaces : June 20 - 23, 2006, Seville, Spain Y1 - 2006 SN - 8478345191 PB - SolarPaces CY - [o.O.] ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Riffelmann, K.-J. A1 - Krödel, M. A1 - Rietbrock, P. T1 - PHITREC - pressurized volumetric air receiver for high temperature solar applications / K.-J. Riffelmann ; B. Hofschmidt ... 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 - 73 EP - 74 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Pitz-Paal, Robert A1 - Böhmer, M. T1 - A new closed/open volumetric receiver concept for parabolictrough collectors (test results) JF - Journal de physique. 9 (1999), H. 3 Y1 - 1999 SN - 1155-4339 SP - 3 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Pitz-Paal, R. A1 - Böhmer, M. T1 - Experimental and numerical evaluation of the performance and flow stability of different types of open volumetric absorbers under non-homogeneous irradiation / R. Pitz-Pahl ; B. Hofschmidt ; M. Böhmer ... JF - Solar energy. 60 (1997), H. 3-4 Y1 - 1997 SN - 0038-092X SP - 135 EP - 150 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Krüger, D. A1 - Hennecke, K. T1 - Results from parabolic trough systems for process heat at the DLR Cologne / D. Krüger ; B. Hoffschmidt ; K. Hennecke ... JF - Solar thermal 2000 : proceedings of the 10th SolarPACES International Symposium on Solar Thermal Concentrating Technologies, Sydney, Australia, 8 - 10 March 2000 ; part of the Y1 - 2000 N1 - International Symposium on Solar Thermal Concentrating Technologies <10, 2000, Sydney> SP - 113 EP - 120 CY - Sydney 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 - Hoffschmidt, Bernhard A1 - Fend, Thomas A1 - Pitz-Paal, Robert A1 - Reutter, Oliver T1 - Two novel high-porosity materials as volumetric receivers for concentrated solar radiation / Thomas Fend ; Robert Pitz-Paal ; Oliver Reutter ... Bernhard Hoffschmidt JF - Solar energy materials & solar cells. 84 (2004), H. 1 Y1 - 2004 SN - 0927-0248 SP - 291 EP - 304 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Fend, Thomas A1 - Pitz-Paal, Robert A1 - Reutter, Oliver T1 - Porous materials as open volumetric solar receivers - Experimental determination of thermophysical and heat transfer properties / Thomas Fend ; Bernhard Hoffschmidt ... JF - Energy. 29 (2004), H. 5 Y1 - 2004 SN - 0360-5442 SP - 823 EP - 834 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Fend, Thomas A1 - Jorgensen, Gary A1 - Küster, Harald T1 - Comparative assessment of solar concentrator materials / Fend, Thomas ; Hoffschmidt, Bernhard ; Jorgensen, Gary ; Küster, Harald ; Krüger, Dirk ; Pitz-Paal, Robert ; Riebrock, Peter ; Riffelmann, Klaus-Jürgen JF - Solar energy. 74 (2003), H. 2 Y1 - 2003 SN - 0038-092X SP - 149 EP - 155 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Fend, Thomas A1 - Jorgensen, Gary T1 - Comparative assessment of solar concentrator materials / Thomas Fend ; Bernhard Hoffschmidt ; Gary Jorgensen ... JF - Renewable energy for local communities of Europe : (toward Rio+10) ; proceedings / EuroSun 2002, the 4th ISES Europe Solar Congress ; Bologna (Italy), 23 - 26 June 2002 / ISES Italia Y1 - 2002 SN - 88-900893-0-X N1 - Eurosun <4, 2002, Bologna> ; International Solar Energy Society SP - paper_125.pdf CY - Bologna ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Faber, Christian T1 - Lighthouse project for North-Rhine Westfalia - Solar thermal R & D Power Planet in Jülich T2 - Energy security, climate change and sustainable development / ed. Jyotirmay Mathur ... Y1 - 2007 SN - 81-88342-81-5 SP - 101 EP - 116 PB - Anamaya Publ. CY - New Delhi ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Buck, R. A1 - Fend, Thomas T1 - Porous materials as volumetric solar receivers : experimental approach towards a detailed characterisation of instability problems / R. Buck ; T. Fend ; B. Hoffschmidt ... 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 - 71 EP - 72 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Becker, Manfred A1 - Fend, Thomas T1 - Theoretical and numerical investigation of flow stability in porous materials applied as volumetric solar receivers / M. Becker ; T. Fend ; B. Hoffschmidt ... JF - Solar energy. 80 (2006), H. 10 Y1 - 2006 SN - 0038-092X N1 - Solar Power and Chemical Energy Systems (SolarPACES’04) SP - 1241 EP - 1248 ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O’Connor, B. A1 - Chico Caminos, Ricardo Alexander A1 - Rendón, C. A1 - Hilger, P. T1 - Concentrating solar power T2 - Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications N2 - The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world. KW - Central receiver power plant KW - Concentrated systems KW - Gas turbine KW - Hybridization KW - Power conversion systems Y1 - 2022 SN - 978-0-12-819734-9 SP - 670 EP - 724 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O’Connor, B. A1 - Chico Caminos, Ricardo Alexander A1 - Rendón, C. A1 - Hilger, P. T1 - Concentrating Solar Power T2 - Earth systems and environmental sciences N2 - The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world. KW - Central receiver power plant KW - Concentrated systems KW - Concentrating solar power KW - Fresnel power plant KW - Gas turbine Y1 - 2021 SN - 978-0-12-409548-9 U6 - https://doi.org/10.1016/B978-0-12-819727-1.00089-3 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Rau, Christoph A1 - Sattler, Johannes Christoph A1 - Anthrakidis, Anette A1 - Teixeira Boura, Cristiano José A1 - O'Connor, P. A1 - Hilger, Patrick T1 - Concentrating solar power T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications Y1 - 2012 SN - 978-0-08-087872-0 U6 - https://doi.org/10.1016/B978-0-08-087872-0.00319-X VL - 3 SP - 595 EP - 636 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Göttsche, Joachim A1 - Sauerborn, Markus A1 - Kaufhold, O. T1 - High Concentration Solar Collectors T2 - Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications N2 - Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this article, different criteria for the choice of technology are analyzed in detail. KW - Central receiver system KW - Concentrated solar collector KW - Solar dish KW - Solar concentration Y1 - 2022 SN - 978-0-12-819734-9 U6 - https://doi.org/10.1016/B978-0-12-819727-1.00058-3 SP - 198 EP - 245 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard A1 - Alexopoulos, Spiros A1 - Göttsche, Joachim A1 - Sauerborn, Markus T1 - High concentration solar collectors T2 - Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications N2 - Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail. KW - Central receiver system KW - Concentrated solar collector KW - Fresnel collector KW - Optical and thermal analysis KW - Solar concentration Y1 - 2012 SN - 978-0-08-087873-7 U6 - https://doi.org/10.1016/B978-0-08-087872-0.00306-1 VL - 3 SP - 165 EP - 209 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoffschmidt, Bernhard T1 - Solar tower power plants T2 - DME Seminar Desalination and Renewable Energies : June 19 and 20 2008, Solar Institut Jülich / Deutsche Meerwasserentsalzung e.V. Y1 - 2008 SN - 978-3-86861-017-8 PB - DME CY - Duisbrug ER - TY - CHAP A1 - Hoffmann, Katharina A1 - Nieren, Monika A1 - Gäb, Martina A1 - Kasper, Anna A1 - Elbers, Gereon T1 - The potential of near infrared spectroscopy (NIRS) for the environmental biomonitoring of plants T2 - International conference on Life Sciences and Technology N2 - In the current environmental condition, the increase in pollution of the air, water, and soil indirectly will induce plants stress and decrease vegetation growth rate. These issues pay more attention to be solved by scientists worldwide. The higher level of chemical pollutants also induced the gradual changes in plants metabolism and decreased enzymatic activity. Importantly, environmental biomonitoring may play a pivotal contribution to prevent biodiversity degradation and plants stress due to pollutant exposure. Several previous studies have been done to monitor the effect of environmental changes on plants growth. Among that, Near Infrared spectroscopy (NIRS) offers an alternative way to observe the significant alteration of plant physiology caused by environmental damage related to pollution. Impairment of photosynthesis, nutrient and oxidative imbalances, and mutagenesis. Y1 - 2019 U6 - https://doi.org/10.1088/1755-1315/276/1/012009 SN - 1755-1315 N1 - IOP Conference Series: Earth and Environmental Science : 276 VL - 276 IS - 012009 SP - 1 EP - 3 ER - TY - JOUR A1 - Hoffmann, Andreas A1 - Uhl, Matthias A1 - Ceblin, Maximilian A1 - Rohrbach, Felix A1 - Bansmann, Joachim A1 - Mallah, Marcel A1 - Heuermann, Holger A1 - Jacob, Timo A1 - Kuehne, Alexander J.C. T1 - Atmospheric pressure plasma-jet treatment of PAN-nonwovens—carbonization of nanofiber electrodes JF - C - Journal of Carbon Research N2 - Carbon nanofibers are produced from dielectric polymer precursors such as polyacrylonitrile (PAN). Carbonized nanofiber nonwovens show high surface area and good electrical conductivity, rendering these fiber materials interesting for application as electrodes in batteries, fuel cells, and supercapacitors. However, thermal processing is slow and costly, which is why new processing techniques have been explored for carbon fiber tows. Alternatives for the conversion of PAN-precursors into carbon fiber nonwovens are scarce. Here, we utilize an atmospheric pressure plasma jet to conduct carbonization of stabilized PAN nanofiber nonwovens. We explore the influence of various processing parameters on the conductivity and degree of carbonization of the converted nanofiber material. The precursor fibers are converted by plasma-jet treatment to carbon fiber nonwovens within seconds, by which they develop a rough surface making subsequent surface activation processes obsolete. The resulting carbon nanofiber nonwovens are applied as supercapacitor electrodes and examined by cyclic voltammetry and impedance spectroscopy. Nonwovens that are carbonized within 60 s show capacitances of up to 5 F g⁻¹. Y1 - 2022 U6 - https://doi.org/10.3390/c8030033 SN - 2311-5629 N1 - This article belongs to the Collection "Nanoporous Carbon Materials for Advanced Technological Applications" VL - 8 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hoffmann, Andreas A1 - Rohrbach, Felix A1 - Uhl, Matthias A1 - Ceblin, Maximilian A1 - Bauer, Thomas A1 - Mallah, Marcel A1 - Jacob, Timo A1 - Heuermann, Holger A1 - Kuehne, Alexander J. C. T1 - Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing JF - Journal of Applied Polymer Science N2 - Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance. KW - batteries and fuel cells KW - electrospinning KW - fibers KW - irradiation KW - porous materials Y1 - 2022 U6 - https://doi.org/10.1002/app.52887 SN - 0021-8995 (Print) SN - 1097-4628 (Online) N1 - Weitere Informationen: Bundesministerium für Bildung und Forschung, Fördernummer: 13XP5036E. Deutsche Forschungsgemeinschaft, Fördernummern: 390874152, 441209207, 327886311 VL - 139 IS - 37 SP - 1 EP - 9 PB - Wiley ER - TY - CHAP A1 - Hoeveler, Bastian A1 - Janser, Frank T1 - The aerodynamically optimized design of a fan-in-wing duct T2 - Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016 Y1 - 2016 SN - 1-85768-371-4 N1 - G1-3-paper.pdf SP - 1 EP - 10 ER - TY - JOUR A1 - Hoeveler, B. A1 - Bauknecht, André A1 - Wolf, C. Christian A1 - Janser, Frank T1 - Wind-Tunnel Study of a Wing-Embedded Lifting Fan Remaining Open in Cruise Flight JF - Journal of Aircraft N2 - It is investigated whether a nonrotating lifting fan remaining uncovered during cruise flight, as opposed to being covered by a shutter system, can be realized with limited additional drag and loss of lift during cruise flight. A wind-tunnel study of a wing-embedded lifting fan has been conducted at the Side Wind Test Facility Göttingen of DLR, German Aerospace Center in Göttingen using force, pressure, and stereoscopic particle image velocimetry techniques. The study showed that a step on the lower side of the wing in front of the lifting fan duct increases the lift-to-drag ratio of the whole model by up to 25% for all positive angles of attack. Different sizes and inclinations of the step had limited influence on the surface pressure distribution. The data indicate that these parameters can be optimized to maximize the lift-to-drag ratio. A doubling of the curvature radius of the lifting fan duct inlet lip on the upper side of the wing affected the lift-to-drag ratio by less than 1%. The lifting fan duct inlet curvature can therefore be optimized to maximize the vertical fan thrust of the rotating lifting fan during hovering without affecting the cruise flight performance with a nonrotating fan. Y1 - 2020 U6 - https://doi.org/10.2514/1.C035422 SN - 1533-3868 VL - 57 IS - 4 PB - AIAA CY - Reston, Va. ER - TY - JOUR A1 - Hoepner, Gert T1 - Info-Web-Generation JF - Dm-compact : academic news for marketeers / Deutscher Direktmarketing Verband e. V.. 2 (2004), H. 3-4 Y1 - 2004 SN - 1573-3181 N1 - engl. Text unter gleichem Titel im gleichen Heft: Seite 12-17 SP - 14 EP - 20 ER - TY - JOUR A1 - Hoehr, Cornelia A1 - Paulßen, Elisabeth A1 - Benard, Francois A1 - Lee, Chris Jaeil A1 - Hou, Xinchi A1 - Badesso, Brian A1 - Ferguson, Simon A1 - Miao, Qing A1 - Yang, Hua A1 - Buckley, Ken A1 - Hanemaayer, Victoire A1 - Zeisler, Stefan A1 - Ruth, Thomas J. A1 - Celler, Anna A1 - Schaffer, Paul T1 - ⁴⁴ᶢSc production using a water target on a 13 MeV cyclotron JF - Nuclear medicine and biology N2 - Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t₁⸝₂ = 3.97 h, Eavg,β⁺ = 1.47 MeV, branching ratio = 94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations. Y1 - 2014 U6 - https://doi.org/10.1016/j.nucmedbio.2013.12.016 SN - 1872-9614 VL - 41 IS - 5 SP - 401 EP - 406 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Hoegen, Anne von A1 - Doncker, Rik W. De A1 - Rütters, René T1 - Teaching Digital Control of Operational Amplifier Processes with a LabVIEW Interface and Embedded Hardware T2 - 2020 23rd International Conference on Electrical Machines and Systems (ICEMS) N2 - Control engineering theory is hard to grasp for undergraduates during the first semesters, as it deals with the dynamical behavior of systems also in combination with control strategies on an abstract level. Therefore, operational amplifier (OpAmp) processes are reasonable and very effective systems to connect mathematical description with actual system’s behavior. In this paper, we present an experiment for a laboratory session in which an embedded system, driven by a LabVIEW human machine interface (HMI) via USB, controls the analog circuits.With this setup we want to show the possibility of firstly, analyzing a first order process and secondly, designing a P-and PI-controller. Thereby, the theory of control engineering is always applied to the empirical results in order to break down the abstract level for the students. Y1 - 2020 U6 - https://doi.org/10.23919/ICEMS50442.2020.9290928 N1 - 23rd International Conference on Electrical Machines and Systems (ICEMS), 24-27 November 2020, Hamamatsu, Japan SP - 1117 EP - 1122 PB - IEEE CY - New York, NY ER - TY - CHAP A1 - Hoegen, Anne von A1 - Doncker, Rik W. De A1 - Bragard, Michael A1 - Hoegen, Svenja von T1 - Problem-based learning in automation engineering: performing a remote laboratory aession aerving various educational attainments T2 - 2021 IEEE Global Engineering Education Conference (EDUCON) N2 - During the Covid-19 pandemic, vocational colleges, universities of applied science and technical universities often had to cancel laboratory sessions requiring students’ attendance. These above of all are of decisive importance in order to give learners an understanding of theory through practical work.This paper is a contribution to the implementation of distance learning for laboratory work applicable for several upper secondary educational facilities. Its aim is to provide a paradigm for hybrid teaching to analyze and control a non-linear system depicted by a tank model. For this reason, we redesign a full series of laboratory sessions on the basis of various challenges. Thus, it is suitable to serve different reference levels of the European Qualifications Framework (EQF).We present problem-based learning through online platforms to compensate the lack of a laboratory learning environment. With a task deduced from their future profession, we give students the opportunity to develop own solutions in self-defined time intervals. A requirements specification provides the framework conditions in terms of time and content for students having to deal with the challenges of the project in a self-organized manner with regard to inhomogeneous previous knowledge. If the concept of Complete Action is introduced in classes before, they will automatically apply it while executing the project.The goal is to combine students’ scientific understanding with a procedural knowledge. We suggest a series of remote laboratory sessions that combine a problem formulation from the subject area of Measurement, Control and Automation Technology with a project assignment that is common in industry by providing extracts from a requirements specification. Y1 - 2021 U6 - https://doi.org/10.1109/EDUCON46332.2021.9453925 N1 - 2021 IEEE Global Engineering Education Conference (EDUCON), 21-23 April 2021, Vienna, Austria SP - 1605 EP - 1614 PB - IEEE CY - New York, NY ER - TY - CHAP A1 - Hoefling, J. A1 - Schirra, Julian A1 - Spohr, A. A1 - Schäfer, Daniel T1 - Induced drag computation with wake model schemes for highly non-planar wing systems T2 - Deutscher Luft- und Raumfahrtkongress 2013 : 10.9. - 12.9.2013, Stuttgart Y1 - 2013 SP - 1 EP - 10 PB - Dt. Ges. für Luft- und Raumfahrt CY - Bonn ER - TY - JOUR A1 - Hodel, U. A1 - Orzati, A. A1 - Marso, M. A1 - Homann, O. A1 - Fox, A. A1 - Hart, A. v. d. A1 - Förster, Arnold A1 - Kordos, P. A1 - Lüth, H. T1 - A novel InAlAs/InGaAs layer structure for monolithically integrated photoreceiver JF - Conference Proceedings: 2000 International Conference on Indium Phosphide and related materials Y1 - 2000 SN - 0-7803-6320-5 N1 - International Conference on Indium Phosphide and Related Materials <12, 2000, Williamsburg, Va.> SP - 466 EP - 469 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - JOUR A1 - Hirschfeld, Julian A. A1 - Lustfeld, Hans A1 - Reißel, Martin A1 - Steffen, Bernhard T1 - A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack JF - International Journal of Energy Research N2 - A novel scheme for detecting inhomogeneous internal currents in a fuel cell stack is presented. In this paper the scheme is investigated for the case that the flow field plates consist of graphite. Then plates of high conductivity, e.g. aluminium between the flow field plates together with small slits in these plates have three effects: (a) Whenever a local inhomogeneity of the electric current occurs at a particular cell in the stack, this will induce a surface current close to that cell perpendicular to the averaged current. This current can be detected. (b) The plates of high conductivity completely prevent the inhomogeneities from spreading to neighbouring cells. (c) Even at the particular cell the inhomogeneity is suppressed as far as possible. Thus this scheme leads to much better diagnostic possibilities and at the same time reduces electric instabilities to an extent, where they probably become harmless. This scheme will first be explained for a simple model to clarify the idea. However, very precise three dimensional computations using realistic parameters are presented, corroborating the results of the simple model. Y1 - 2010 U6 - https://doi.org/10.1002/er.1662 SN - 0363-907X VL - 34 IS - 3 SP - 293 EP - 301 PB - Wiley CY - London ER - TY - JOUR A1 - Hirschfeld, Julian A. A1 - Lustfeld, Hans A1 - Reißel, Martin A1 - Steffen, Bernhard T1 - Tomographic diagnostics of current distributions in a fuel cell stack JF - International Journal of Energy Research N2 - A novel tomographic scheme for analysing the state of any single membrane electrode assembly (MEA) in a stack is suggested. Plates of very high conductivity placed between every fuel cell and slitted in an appropriate manner cause surface currents at well-defined locations of the stack. We show that knowing these surface currents, information about anomalies of the currents in a MEA can be obtained using the methods of tomography. The results are mathematically not unique. However, when assuming plausible defect structures, one can exclude improbable deficiencies by applying a special form of simulated annealing. We present numerical calculations of typical examples demonstrating that the essential defects of the MEA in any single cell of the stack can be detected and their extent can be determined. Y1 - 2010 U6 - https://doi.org/10.1002/er.1634 SN - 0363-907X VL - 34 IS - 3 SP - 284 EP - 292 PB - Wiley CY - London ER - TY - JOUR A1 - Hirschberg, Rainer T1 - Computer-Aided-Engineering in der Technischen Gebäudeausrüstung JF - computer spezial (1994) Y1 - 1994 N1 - Beil. zu: Tiefbau, Ingenieurbau, Strassenbau (1994)Nr.5 SP - 32 EP - 37 ER - TY - JOUR A1 - Hirschberg, Rainer T1 - Decentral pumps in heating systems - a new hydraulic approac JF - 1st International Rotating Equipment Conference - Pumps and Compressors, 9th Pump Users International Forum, 9. Internationales Pumpenanwenderforum, Final Report, Düsseldorf, DE, 28.-29. Oct, 2008 Y1 - 2008 SP - 1 EP - 10 PB - - ER - TY - CHAP A1 - Hirsch, Tobias A1 - Ahlbrink, Nils A1 - Pitz-Paal, Robert A1 - Teixeira Boura, Cristiano José A1 - Hoffschmidt, Bernhard A1 - Gall, Jan A1 - Abel, Dirk A1 - Nolte, Vera A1 - Wirsum, Manfred A1 - Andersson, Joel A1 - Diehl, Moritz T1 - Dynamic simulation of a solar tower system with open volumetric receiver - a review on the ViCERP project T2 - SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain Y1 - 2011 CY - Granada ER - TY - CHAP A1 - Hirsch, Tobias A1 - Abel, Dirk A1 - Bohn, Dieter A1 - Diehl, Moritz A1 - Hoffschmidt, Bernhard A1 - Pitz-Paal, Robert T1 - The Virtual Institute for Central Receiver Power Plants - vICERP T2 - SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings Y1 - 2009 SN - 9783000287558 PB - Deutsches Zentrum f. Luft- u. Raumfahrt CY - Stuttgart ER - TY - CHAP A1 - Hirsch, G. A1 - Wahle, Michael ED - Leadon, Bernhard M. T1 - Design criteria for dynamic vibration absorbers with regard to the nonproportional damping T2 - Proceedings / The Third US National Conference on Wind Engineering Research, February 26 - March 1, 1978, University of Florida, Gainesville Y1 - 1978 N1 - NSF grant no. PFR77-10170 A01. - US National Conference on Wind Engineering Research <3, 1978, Gainesville, Fla.> SP - 507 EP - 510 PB - Univ. of Florida, Div. of Continuing Education Publ. CY - Gainsville, Fla. ER - TY - CHAP A1 - Hippe, Jonas A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten T1 - Propulsion System Qualification of a 25 kg VTOL-UAV: Hover Performance of Single and Coaxial Rotors and Wind-Tunnel Experiments on Cruise Propellers T2 - Deutscher Luft- und Raumfahrtkongress - DLRK 2020 N2 - This paper presents an approach for UAV propulsion system qualification and validation on the example of FH Aachen's 25 kg cargo UAV "PhoenAIX". Thrust and power consumption are the most important aspects of a propulsion system's layout. In the initial design phase, manufacturers' data has to be trusted, but the validation of components is an essential step in the design process. This process is presented in this paper. The vertical takeoff system is designed for efficient hover; therefore, performance under static conditions is paramount. Because an octo-copter layout with coaxial rotors is considered, the impact of this design choice is analyzed. Data on thrust, voltage stability, power consumption, rotational speed, and temperature development of motors and controllers are presented for different rotors. The fixed-wing propulsion system is designed for efficient cruise flight. At the same time, a certain static thrust has to be provided, as the aircraft needs to accelerate to cruise speed. As for the hover-system, data on different propellers is compared. The measurements were taken for static conditions, as well as for different inflow velocities, using the FH-Aachen's wind-tunnel. Y1 - 2020 N1 - 69. Deutscher Luft- und Raumfahrtkongress 2020, 1. September 2020 - 3. September 2020, online ER - TY - CHAP A1 - Hinke, Christian A1 - Vervier, Luisa A1 - Brauner, Philipp A1 - Schneider, Sebastian A1 - Steuer-Dankert, Linda A1 - Ziefle, Martina A1 - Leicht-Scholten, Carmen T1 - Capability configuration in next generation manufacturing T2 - Forecasting next generation manufacturing : digital shadows, human-machine collaboration, and data-driven business models N2 - Industrial production systems are facing radical change in multiple dimensions. This change is caused by technological developments and the digital transformation of production, as well as the call for political and social change to facilitate a transformation toward sustainability. These changes affect both the capabilities of production systems and companies and the design of higher education and educational programs. Given the high uncertainty in the likelihood of occurrence and the technical, economic, and societal impacts of these concepts, we conducted a technology foresight study, in the form of a real-time Delphi analysis, to derive reliable future scenarios featuring the next generation of manufacturing systems. This chapter presents the capabilities dimension and describes each projection in detail, offering current case study examples and discussing related research, as well as implications for policy makers and firms. Specifically, we discuss the benefits of capturing expert knowledge and making it accessible to newcomers, especially in highly specialized industries. The experts argue that in order to cope with the challenges and circumstances of today’s world, students must already during their education at university learn how to work with AI and other technologies. This means that study programs must change and that universities must adapt their structural aspects to meet the needs of the students. Y1 - 2022 SN - 978-3-031-07733-3 U6 - https://doi.org/10.1007/978-3-031-07734-0_6 SP - 95 EP - 106 PB - Springer CY - Cham ER - TY - CHAP A1 - Hingley, Peter A1 - Dikta, Gerhard T1 - Finding a well performing box-jenkins forecasting model for annualised patent filings counts T2 - International Symposium on Forecasting, Thessaloniki, Greece, June 2019 Y1 - 2019 ER - TY - JOUR A1 - Hillgärtner, Michael A1 - Stonies, R. A1 - Peier, D. A1 - Voges, E. T1 - Design of Low Cost Antennas for Reverberation Chambers JF - Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility : [EMC Week 2005, Zurich, Switzerland, February 13 - 18 ; technical exhibition on EMC and RF/microwave Measurements and Instrumentation (February 15 - 17)] / [Laboratory for Electromagnetic Fields and Microwave Electronics, Swiss Federal Institute of Technology Zurich] Y1 - 2005 SN - 3-9521199-9-7 N1 - Nebent.: EMC Zurich 2005 Symposium proceedings. - International Zurich Symposium and Technical Exhibition on Electromagnetic Compatibility <16, 2005, Zürich> Institut für Feldtheorie und Höchstfrequenztechnik PB - ETH-Zentrum-IFH CY - Zürich ER - TY - JOUR A1 - Hillgärtner, Michael A1 - Peier, Dirk T1 - Design of a Measurement Setup for the Impedance of Low-Resistance Plate-Conductors in the RF-Range JF - Proceedings of the 10th International Conference on Optimization of Electrical and Electronic Equipment, OPTIM '06, Braşov, May 18 - 20, 2006 / ed. by The Transilvania University of Braşov, Faculty of Electrical Engineering and Computer Science. [Ed. Mihai Cernat .̤] . - Vol. 1: Keynote addresses, electrotechnics Y1 - 2006 SN - 978-973-635703-9 N1 - International Conference on Optimization of Electrical and Electronic Equipment <10, 2006, Braşov>; OPTIM <10, 2006, Braşov> SP - 59 EP - 64 CY - Braşov ER - TY - JOUR A1 - Hillgärtner, Michael A1 - Kappel, U. T1 - Radiating Impedance of Mains Cabling During Emissions Testing JF - EMC Europe 2006 Barcelona : International Symposium on Electromagnetic Compatibility; September 4 - 8, 2006, Campus Nord, Technical University of Catalonia, Barcelona, Spain / [organized by Technical University of Catalonia (UPC) ... Ed. and publ. by: Ferran Silva ...]. - Vol. 1: Proceedings 1 Y1 - 2006 SN - 84-689-9439-1 N1 - EMC Europe <7,2006,Barcelona>; International Symposium on Electromagnetic Compatibility <7, 2006, Barcelona> SP - 17 EP - 22 CY - Barcelona ER - TY - JOUR A1 - Hillgärtner, Michael T1 - Normative Regulations JF - ECPE Cluster Seminar EMC in Hybrid and Electric Vehicles : 18 May 2010, Fraunhofer Institute Erlangen Y1 - 2010 N1 - Seminar EMC in Hybrid and Electric Vehicles <2010, Erlangen> PB - European Center for Power Electronics CY - Nürnberg ER - TY - JOUR A1 - Hillen, Walter A1 - Unglauben, F. A1 - Wirtz, G. T1 - Architectures and Modeling of Distributed Image Information Systems. Unglauben, F.; Hillen, W.; Wirtz, G. JF - Proceedings : July 14 - 18, 2002, Orlando, Florida, USA ; [jointly with the 8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002)] / organized by IIIS, International Institute of Informatics and Systemics. Ed. by Nagib Callaos Y1 - 2002 SN - 9800781501 N1 - World Multiconference on Systemics, Cybernetics and Informatics ; (6, 2002, Orlando, Fla.) ; International Conference on Information Systems, Analysis and Synthesis ; (8, 2002, Orlando, Fla.) ; International Institute of Informatics and Systemics ; World Multiconference on Systemics, Cybernetics and Informatics ; (6 : ; 2002.07.14-18 : ; Orlando, Fla.) ; SCI 2002 ; (6 : ; 2002.07.14-18 : ; Orlando, Fla.) ; International Conference on Information Systems Analysis and Synthesis ; (8 : ; 2002.07.14-18 : ; Orlando, Fla.) ; ISAS 2002 ; (8 : ; 2002.07.14-18 : ; Orlando, Fla.) PB - IIIS CY - Orlando, Fla. ER - TY - JOUR A1 - Hillen, Walter A1 - Unglauben, F. A1 - Murdfield, M. T1 - Study of Database Connections for a Java Medical Image Viewer. Unglauben, F.; Hillen, W.; Murdfield, M. JF - Intelligente, innovative Produktentwicklung für die industrielle Praxis. Blümel, Bernd; Stenzel, Horst [Hrsg.] Y1 - 2001 N1 - Forschungsverbund Multimedia an Fachhochschulen in Nordrhein-Westfalen SP - 29 EP - 33 PB - Forschungverbund Multimedia an Fachhochschulen CY - Köln ER - TY - JOUR A1 - Hillen, Walter A1 - Schmitt, W. A1 - Bockemühl, J. T1 - Signal-to-Noise Performance of a digital dental X-ray Detector JF - Computer assisted radiology : proceedings of the International Symposium on Computer and Communication Systems for Image Guided Diagnosis and Therapy / CAR '95 Berlin, June 21 - 24, 1995. Ed. by H. U. Lemke Y1 - 1995 SN - 3-540-59177-X N1 - CAR <6, 1995, Berlin> PB - Springer CY - Berlin [u.a.] ER - TY - JOUR A1 - Hillen, Walter A1 - Schiebel, U. A1 - Zaengel, T. T1 - A selenium-based detector for digital slot-radiography JF - Medical Imaging II Y1 - 1988 N1 - Proceedings of SPIE ; 914 SP - 253 ER - TY - JOUR A1 - Hillen, Walter A1 - Schiebel, U. A1 - Zaengel, T. T1 - Image quality in selenium-based digital radiography. Schiebel, U.; Hillen, W.; Zaengel, T. JF - Medical Imaging Y1 - 1986 N1 - Proceedings of SPIE ; 626 SP - 176 ER - TY - JOUR A1 - Hillen, Walter A1 - Schiebel, U. A1 - Zaengel, T. T1 - Imaging performance of a digital storage phosphor system JF - Medical Physics. 14 (1987), H. 5 Y1 - 1987 SN - 0094-2405 SP - 744 EP - 751 ER - TY - JOUR A1 - Hillen, Walter A1 - Rupp, S. A1 - Schiebel, U. A1 - Zaengel, Thomas T. T1 - Imaging performance of a selenium-based detector for high-resolution radiography JF - Medical Imaging III: Image Formation Y1 - 1989 SN - 0-8194-0125-0 N1 - Proceedings of SPIE ; 1090 SP - 296 ER - TY - JOUR A1 - Hillen, Walter A1 - Lehmann, T. A1 - Horn, H. A1 - Schmitt, W. T1 - Identification of Dental Fixtures in Intraoral X-rays. Lehmann, T.; Hillen, W.; Horn, H.; Schmitt, W. JF - Medical imaging 1996 : image processing ; 12 - 15 February 1996, Newport Beach, California / Murray H. Loew ... chairs/ed. Y1 - 1996 SN - 0-8194-2085-9 N1 - Proceedings of SPIE; 2710 SP - 584 EP - 584 PB - SPIE - The International Society for Optical Engineering CY - Bellingham, Wash. ER - TY - JOUR A1 - Hillen, Walter A1 - Lehmann, T. A1 - Horn, H. A1 - Schmitt, W. T1 - IDEFIX - Identification of Dental Fixtures. Lehmann, T.; Hillen, W.; Horn, H.; Schmitt, W. JF - 5th European Congress on Dental and Maxillo-Facial Radiology : 30th Annual meeting of Working Group for Dental Radiology in the German Scientific Society for Dentistry, November 8-11, 1995, Cologne : abstracts Y1 - 1995 N1 - European Congress on Dental and Maxillo-Facial Radiology <5, 1995, Köln> ER - TY - JOUR A1 - Hillen, Walter A1 - Eckenbach, W. A1 - Quadflieg, Peter A1 - Zaengel, Thomas T. T1 - Signal-to-noise performance of a CsI fluorescent screen JF - Medical Imaging V: Image physics Y1 - 1991 SN - 0-8194-0538-8 N1 - Proceedings of SPIE ; 1443 SP - 120 EP - 131 ER - TY - JOUR A1 - Hillen, Walter A1 - Barry, J. C. A1 - Pongs, U. M. T1 - Algorithm for Purkinje Image I and IV and Limbus Centre Location. Barry, J. C.; Pongs, U. M.; Hillen, W. JF - Computers in Biology and Medicine. 27 (1997), H. 6 Y1 - 1997 SN - 0010-4825 SP - 515 EP - 531 ER - TY - JOUR A1 - Hillen, Walter A1 - Alper Selver, M. A1 - Fischer, Felix A1 - Kuntalp, Mehmet T1 - A software tool for interactive generation, representation, and systematical storage of transfer functions for 3D medical images / Alper Selver, M. ; Fischer, Felix ; Kuntalp, Mehmet ; Hillen, Walter JF - Computer Methods and Programs in Biomedicine. 86 (2007), H. 3 Y1 - 2007 SN - 0169-2607 SP - 270 EP - 280 PB - - ER - TY - JOUR A1 - Hillen, Walter T1 - Properties of hadron final states in e+e− annihilation at 13 GeV and 17 GeV center of mass energies. TASSO Collaboration JF - Physics Letters B. 83 (1979), H. 2 Y1 - 1979 SN - 0370-2693 SP - 261 EP - 266 ER - TY - JOUR A1 - Hillen, Walter T1 - A measurement of σtot(e+e− → hadrons) for cm energies between 12.0 and 36.7 GeV. TASSO Collaboration JF - Physics Letters B. 113 (1982), H. 6 Y1 - 1982 SP - 499 EP - 508 ER - TY - JOUR A1 - Hillen, Walter T1 - Scale braking in inclusive charged particle production by e--e+ annihilation. TASSO Collaboration JF - Physics Letters B. 114 (1982), H. 1 Y1 - 1982 SN - 0370-2693 SP - 65 EP - 70 ER - TY - JOUR A1 - Hillen, Walter T1 - Charged pion production in e--e+ annihilation at 14, 22 and 34 GeV c.m. energies. TASSO Collaboration JF - Physics Letters B. 113 (1982), H. 1 Y1 - 1982 SN - 0370-2693 SP - 98 EP - 104 ER - TY - JOUR A1 - Hillen, Walter T1 - Charged pion, kaon, proton and antiproton production in high energy e+e− annihilations. TASSO Collaboration JF - Physics Letters B. 94 (1980), H. 3 Y1 - 1980 SN - 0370-2693 SP - 444 EP - 449 ER - TY - JOUR A1 - Hillen, Walter T1 - Comparison of e+e− annihilation with QCD and determination of the strong coupling constant . TASSO Collaboration JF - Physics Letters B. 94 (1980), H. 3 Y1 - 1980 SN - 0370-2693 SP - 437 EP - 443 ER - TY - JOUR A1 - Hillen, Walter T1 - K0 production in e+e− annihilations at 30 GeV center of mass energy. TASSO Collaboration JF - Physics Letters B. 94 (1980), H. 1 Y1 - 1980 SN - 0370-2693 SP - 91 EP - 95 ER - TY - JOUR A1 - Hillen, Walter T1 - Test of QED in e+e− annihilation at energies between 12 and 31.6 GeV. TASSO Collaboration JF - Physics Letters B. 94 (1980), H. 2 Y1 - 1980 SN - 0370-2693 SP - 259 EP - 265 ER - TY - JOUR A1 - Hillen, Walter T1 - Rapid growth of charged particle multiplicity in high energy e+e− annihilations. TASSO Collaboration JF - Physics Letters B. 89 (1980), H. 3-4 Y1 - 1980 SN - 0370-2693 SP - 418 EP - 422 ER - TY - JOUR A1 - Hillen, Walter T1 - Production and properties of the τ-lepton in e+e− annihilation at C.M. energies from 12 to 31.6 GeV. TASSO Collaboration JF - Physics Letters B. 92 (1980), H. 1-2 Y1 - 1980 SN - 0370-2693 SP - 199 EP - 205 ER - TY - JOUR A1 - Hillen, Walter T1 - Evidence for planar events in e+e− annihilation at high energies. TASSO Collaboration JF - Physics Letters B. 86 (1979), H. 2 Y1 - 1979 SN - 0370-2693 SP - 243 EP - 249 ER - TY - JOUR A1 - Hillen, Walter T1 - Energy scan for narrow states in e+e− annihilation at C.M. energies between 29.90 and 31.46 GeV. TASSO Collaboration JF - Physics Letters B. 88 (1979), H. 1-2 Y1 - 1979 SN - 0370-2693 SP - 199 EP - 202 ER - TY - JOUR A1 - Hillen, Walter T1 - Charge asymmetry and weak interaction effects in e+e−→μ+μ− and e+e−→τ+τ− . TASSO Collaboration JF - Physics Letters B. 110 (1982), H. 2 Y1 - 1982 SN - 0370-2693 SP - 173 EP - 180 ER - TY - JOUR A1 - Hillen, Walter T1 - π0 production by e+e− annihilation at 14 and 34 GeV c.m. energy . TASSO Collaboration JF - Physics Letters B. 108 (1982), H. 1 Y1 - 1982 SN - 0370-2693 SP - 71 EP - 76 ER - TY - JOUR A1 - Hillen, Walter T1 - Exclusive proton-antiproton production in two photon collisions . TASSO Collaboration JF - Physics Letters B. 108 (1982), H. 1 Y1 - 1982 SN - 0370-2693 SP - 67 EP - 70 ER - TY - JOUR A1 - Hillen, Walter T1 - High pT hadron production in photon-photon collisions . TASSO Collaboration JF - Physics Letters B. 107 (1982), H. 4 Y1 - 1982 SN - 0370-2693 SP - 290 EP - 296 ER - TY - JOUR A1 - Hillen, Walter T1 - Λ, Image production in e+e- annihilation at 33 GeV centre of mass energy. TASSO Collaboration JF - Physics Letters B. 105 (1981), H. 4 Y1 - 1981 SN - 0370-2693 SP - 75 EP - 80 ER - TY - JOUR A1 - Hillen, Walter T1 - Evidence for charged primary partons in e+e− → 2 jets. TASSO Collaboration JF - Physics Letters B. 100 (1981), H. 4 Y1 - 1981 SN - 0370-2693 SP - 357 EP - 363 ER - TY - JOUR A1 - Hillen, Walter T1 - Search for new sequential leptons in e+e- annihilation at petra energies. TASSO Collaboration JF - Physics Letters B. 99 (1981), H. 2 Y1 - 1981 SN - 0370-2693 SP - 163 EP - 168 ER - TY - JOUR A1 - Hillen, Walter T1 - Evidence for a spin-1 gluon in three-jet events. TASSO Collaboration JF - Physics Letters B. 97 (1980), H. 3-4 Y1 - 1980 SN - 0370-2693 SP - 453 EP - 458 ER - TY - JOUR A1 - Hillen, Walter T1 - RHO-RHO production by two photon scattering. TASSO Collaboration JF - Physics Letters B. 97 (1980), H. 3-4 Y1 - 1980 SN - 0370-2693 SP - 448 EP - 452 ER - TY - GEN A1 - Hille, Sebastian A1 - Stumpf, Eike A1 - Mayntz, Joscha A1 - Dahmann, Peter T1 - Prediction of sound exposure caused by a landing motor glider with recuperating propellers T2 - AIAA SCITECH 2023 Forum N2 - This paper presents an approach to predicting the sound exposure on the ground caused by a landing aircraft with recuperating propellers. The noise source along the trajectory of a flight specified for a steeper approach is simulated based on measurements of sound power levels and additional parameters of a single propeller placed in a wind tunnel. To validate the measured data/measurement results, these simulations are also supported by overflight measurements of a test aircraft. It is shown that the simple source models of propellers do not provide fully satisfactory results since the sound levels are estimated too low. Nevertheless, with a further reference comparison, margins for an acceptable increase in the sound power level of the aircraft on its now steeper approach path could be estimated. Thus, in this case, a +7 dB increase in SWL would not increase the SEL compared to the conventional approach within only 2 km ahead of the airfield. Y1 - 2023 U6 - https://doi.org/10.2514/6.2023-0211 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, Md & Online PB - AIAA CY - Reston, Va. ER - TY - GEN A1 - Hezel, Fabian A1 - Frauenrath, Tobias A1 - Renz, Wolfgang A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - Feasibility of CINE Myocardial T2* Mapping Using Susceptibility Weighted Gradient-Echo Imaging at 7.0 T T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - This study is designed to demonstrate the promise of susceptibility weighted 2D CINE FLASH and T2* Mapping of the heart at 7T. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - JOUR A1 - Heuermann, Holger A1 - Thalayasingam, K. T1 - Novel vector non-linear measurement system for intermodulation measurements / Thalayasingam, K.; Heuermann, H. JF - European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE Y1 - 2009 SN - 978-1-4244-4748-0 N1 - European Microwave Conference ; (39 : ; 2009.09.29-10.01 : ; Rome) SP - 926 EP - 929 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Heuermann, Holger A1 - Stolle, Reinhard A1 - Schiek, Burkhard T1 - Novel Algorithms for FMCW Range Finding with Microwaves. Stolle, R.; Heuermann, H.; Schiek, B. Y1 - 1995 N1 - Conference proceedings / IEEE NTC '95, the Microwave Systems Conference; NTC <1995, Orlando, Fla.> SP - 129 EP - 132 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - The double-LNN Calibration technique for scattering parameter measurements of microstrip devices JF - Conference proceedings Y1 - 1995 N1 - European Microwave Conference <25, 1995, Bologna> SP - 343 EP - 347 PB - NEXUS House CY - Kent ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Calibration of network analyser measurements with leakage errors JF - Electronics letters. 30 (1994), H. 1 Y1 - 1994 SN - 0013-5194 SP - 52 EP - 53 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Results of Network Analyzer Measurements with Leakage Errors Corrected with the TMS-15-Term Procedure Y1 - 1994 N1 - 1994 IEEE MTT-S International Microwave Symposium digest : May 23 - 27, 1994, San Diego Convention Center, San Diego, California / H. J. Kuno, ed. SP - 1361 EP - 1364 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Scattering Parameter Measurements of Microstrip Devices using the Double-LNN Calibration Technique JF - Conference proceedings : [Palais des Festivals et des Congrès Cannes, France, 5 - 8 September 1994] Y1 - 1994 SN - 0-9518032-5-5 N1 - European Microwave Conference <24, 1994, Cannes> PB - Nexus Business Communications CY - Swanley ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - LNN (Line-Network-Network): Verfahren zur Kalibrierung von Netzwerkanalysatoren JF - Kleinheubacher Berichte : Vorträge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 36. 1992 (1992) Y1 - 1992 SP - 327 EP - 335 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Line Network Network (LNN): an alternative in-fixture calibration procedure JF - IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 45 (1997), H. 3 Y1 - 1997 SN - 0018-9480 SP - 408 EP - 413 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - The In-Fixture Calibration Procedure Line-Network-Network-LNN JF - Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community] Y1 - 1992 SN - 0-946821-23-2 N1 - European Microwave Conference <23, 1993, Madrid> SP - 500 EP - 505 PB - Reed Exhibition Companies CY - Tunbridge Wells ER -