TY - JOUR A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Perez-Viana, Daniel A1 - Simmen, Hans-Peter A1 - Neuhaus, Valentin A1 - Pape, Hans-Christoph A1 - Prescher, Andreas A1 - Ciritsis, Bernhard T1 - Biomechanical in vitro examination of a standardized low-volume tubular femoroplasty JF - Clinical Biomechanics N2 - Background Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far. Methods 10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed. Findings Compared to the control group, the work to fracture could be increased by 33.2%. The fracture force increased by 19.9%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry. Interpretation The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results. Y1 - 2020 U6 - https://doi.org/10.1016/j.clinbiomech.2020.105104 VL - 80 IS - Art. 105104 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Horbach, Andreas A1 - Staat, Manfred T1 - Optical strain measurement for the modeling of surgical meshes and their porosity JF - Current Directions in Biomedical Engineering N2 - The porosity of surgical meshes makes them flexible for large elastic deformation and establishes the healing conditions of good tissue in growth. The biomechanic modeling of orthotropic and compressible materials requires new materials models and simulstaneoaus fit of deformation in the load direction as well as trannsversely to to load. This nonlinear modeling can be achieved by an optical deformation measurement. At the same time the full field deformation measurement allows the dermination of the change of porosity with deformation. Also the socalled effective porosity, which has been defined to asses the tisssue interatcion with the mesh implants, can be determined from the global deformation of the surgical meshes. Y1 - 2018 U6 - https://doi.org/10.1515/cdbme-2018-0045 SN - 2364-5504 VL - Band 4 IS - 1 SP - 181 EP - 184 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Horbach, Andreas A1 - Duong, Minh Tuan A1 - Staat, Manfred T1 - Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement JF - Journal of the mechanical behavior of biomedical materials Y1 - 2017 U6 - https://doi.org/10.1016/j.jmbbm.2017.06.012 SN - 1751-6161 VL - 74 SP - 400 EP - 410 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Honarvarfard, Elham A1 - Gamella, Maria A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - An enzyme-based reversible Controlled NOT (CNOT) logic gate operating on a semiconductor transducer JF - Applied Materials Today N2 - An enzyme-based biocatalytic system mimicking operation of a logically reversible Controlled NOT (CNOT) gate has been interfaced with semiconductor electronic transducers. Electrolyte–insulator–semiconductor (EIS) structures have been used to transduce chemical changes produced by the enzyme system to an electronically readable capacitive output signal using field-effect features of the EIS device. Two enzymes, urease and esterase, were immobilized on the insulating interface of EIS structure producing local pH changes performing XOR logic operation controlled by various combinations of the input signals represented by urea and ethyl butyrate. Another EIS transducer was functionalized with esterase only, thus performing Identity (ID) logic operation for the ethyl butyrate input. Both semiconductor devices assembled in parallel operated as a logically reversible CNOT gate. The present system, despite its simplicity, demonstrated for the first time logically reversible function of the enzyme system transduced electronically with the semiconductor devices. The biomolecular realization of a CNOT gate interfaced with semiconductors is promising for integration into complex biomolecular networks and future biosensor/biomedical applications. KW - Electrolyte–insulator–semiconductor KW - Capacitive field-effect KW - CNOT KW - XOR KW - Enzyme logic gate Y1 - 2017 U6 - https://doi.org/10.1016/j.apmt.2017.08.003 SN - 2352-9407 VL - 9 SP - 266 EP - 270 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Honarvarfard, Elham A1 - Gamella, Maria A1 - Channaveerappa, Devika A1 - Darie, Costel C. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - Electrochemically Stimulated Insulin Release from a Modified Graphene–functionalized Carbon Fiber Electrode JF - Electroanalysis N2 - A graphene-functionalized carbon fiber electrode was modified with adsorbed polyethylenimine to introduce amino functionalities and then with trigonelline and 4-carboxyphenylboronic acid covalently bound to the amino groups. The trigonelline species containing quarterized pyridine groups produced positive charge on the electrode surface regardless of the pH value, while the phenylboronic acid species were neutral below pH 8 and negatively charged above pH 9 (note that their pKa=8.4). The total charge on the monolayer-modified electrode was positive at the neutral pH and negative at pH > 9. Note that 4-carboxyphenylboronic acid was attached to the electrode surface in molar excess to trigonelline, thus allowing the negative charge to dominate on the electrode surface at basic pH. Negatively charged fluorescent dye-labeled insulin (insulin-FITC) was loaded on the modified electrode surface at pH 7.0 due to its electrostatic attraction to the positively charged interface. The local pH in close vicinity to the electrode surface was increased to ca. 9–10 due to consumption of H+ ions upon electrochemical reduction of oxygen proceeding at the potential of −1.0 V (vs. Ag/AgCl) applied on the modified electrode. The process resulted in recharging of the electrode surface to the negative value due to the formation of the negative charge on the phenylboronic acid groups, thus resulting in the electrostatic repulsion of insulin-FITC and stimulating its release from the electrode surface. The insulin release was characterized by fluorescence spectroscopy (using the FITC-labeled insulin), by electrochemical measurements on an iridium oxide, IrOx, electrode and by mass spectrometry. The graphene-functionalized carbon fiber electrode demonstrated significant advantages in the signal-stimulated insulin release comparing with the carbon fiber electrode without the graphene species. Y1 - 2017 U6 - https://doi.org/10.1002/elan.201700095 SN - 1521-4109 VL - 29 IS - 6 SP - 1543 EP - 1553 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Holtschoppen, Britta A1 - Butenweg, Christoph A1 - Meskouris, Konstantin T1 - Seismic design of non-structural components in industrial facilities JF - International journal of engineering under uncertainty Y1 - 2009 SN - 0975-4806 VL - Volume 1 SP - 1 EP - 13 ER - TY - JOUR A1 - Holtschoppen, B. A1 - Butenweg, Christoph A1 - Meskouris, Konstantin T1 - Erdbebensichere Auslegung von Industrieanlagen JF - Der Bauingenieur : die richtungsweisende Zeitschrift im Bauingenieurswesen ; offizielle Zeitschrift der VDI-Gesellschaft Bautechnik Y1 - 2009 SN - 0005-6650 IS - März SP - S9 EP - S14 PB - VDI Fachmedien CY - Düsseldorf ER - 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 - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Hasselmann, Willi T1 - Die Bedeutung der Baukosten für Wirtschaftlichkeitsbetrachtungen und die Projektentwicklung / Hasselmann, Willi ; Holthaus Ursula JF - Kosten im Hochbau : Praxis-Handbuch und Kommentar zur DIN 276 ; mit 23 Tabellen / Autoren: Bert Bielefeld ... Hrsg.: Udo Blecken ... Y1 - 2007 SN - 978-3-481-02245-7 SP - 125 EP - 157 PB - Müller CY - Köln ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Boenert, Lothar T1 - Alternative Brandschutzkonstruktionen führen zu Kostenreduzierungen / Boenert, Lothar ; Holthaus, Ursula JF - Trockenbau, Akustik : Magazin für Planung und Ausführung (2003) Y1 - 2003 SN - 0179-8006 SP - 30 EP - 33 ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Blecken, Udo A1 - Meinen, Heiko T1 - Vergabeentscheidung und Wirtschaftlichkeitsberechnung von PPP/PFI-Projekten in der Bauwirtschaft / Udo Blecken, Heiko Meinen, Ursula Holthaus JF - Bautechnik: Zeitschrift für den gesamten Ingenieurbau. 81 (2004), H. 8 Y1 - 2004 SN - 1437-0999 N1 - ISSN 0932-8351 (print) SP - 648 EP - 657 ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Blecken, Udo A1 - Gralla, Mike T1 - PPP-Projekte: Strukturelle Kostenvergleichsuntersuchungen zwischen Eigenrealisierung der öffentlichen Auftraggeber und PPP-Anbietern / Blecken, Udo ; Gralla, Mike ; Holthaus, Ursula JF - Bautechnik. 84 (2007), H. 1 Y1 - 2007 SN - 0932-8351 SP - 25 EP - 34 ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Blecken, Udo T1 - Marktdatenbasiertes Ertragsprognosemodell für die Projektentwicklung / Blecken, Udo; Holthaus, Ursula JF - Baubetrieb und Bauwirtschaft - Festschrift Prof. Gert Stadler Y1 - 2004 SN - 3-902465-09-3 SP - 251 EP - 269 PB - Verlag der TU Graz CY - Graz ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula A1 - Blecken, Udo T1 - Nutzenkosten: DIN 18960-2008 - Leistungsfähige Grundlage für die zielorientierte Planung der Lebenszykluskosten / Blecken, Udo ; Holthaus-Sellheier, Ursula JF - Bautechnik. 85 (2008), H. 7 Y1 - 2008 SN - 1437-0999 SP - 464 EP - 471 ER - TY - JOUR A1 - Holthaus-Sellheier, Ursula T1 - Senkung der Baukosten und Reduzierung der Preisunsicherheit mit Hilfe der Risikoabwicklung über die Optionspreistheorie mit Realoptionen JF - Risikomanagement in der Bauwirtschaft : Tagungsband / Baubetriebs- und Bauwirtschaftssymposium 02. April 2004. [Hrsg.: Technische Universität Graz, Institut für Baubetrieb und Bauwirtschaft. Red.: Reinhild Nöstlthaller ... ] Y1 - 2004 SN - 3-901351-91-4 N1 - Baubetriebs- und Bauwirtschaftssymposium <2, 2004, Graz> SP - 103 EP - 114 PB - Verl. der Techn. Univ. CY - Graz 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 - 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 - 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 - 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 - 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 - Hennecke, K. T1 - Solare Heißlufterzeugung für Temperaturen bis über 250 Grad C JF - Tagung München, 16. und 17. März 1999 . 1999. - (VDI-Berichte ; 1457) Y1 - 1999 SN - 3-18-091457-2 SP - 323 EP - 332 PB - VDI-Verl. CY - Düsseldorf 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 - Krödel, Matthias A1 - Geigl, Florian T1 - Die Kraft der Sonne / Matthias Krödel ; Florian Geigl ; Bernhard Hoffschmidt JF - Nachrichten : Magazin des Deutschen Zentrums für Luft- und Raumfahrt / DLR (2002) Y1 - 2002 SN - 0937-0420 SP - 18 EP - 19 ER - TY - JOUR A1 - Hoffschmidt, Bernhard A1 - Koll, Gerrit T1 - Die Zukunft der Stromerzeugung ; die Entwicklung der Luftreceivertechnologie bei Kraftanlagen München / Gerrit Koll ; Berhard Hoffschmidt JF - Nachrichten : Magazin des Deutschen Zentrums für Luft- und Raumfahrt / DLR (2005) Y1 - 2005 SN - 0937-0420 N1 - Sonderheft Solarforschung SP - 42 EP - 46 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 - 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, M. 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 - JOUR A1 - Hoffschmidt, Bernhard T1 - Keramische Mischer : Überhitzung ausgeschlossen JF - Nachrichten : Magazin des Deutschen Zentrums für Luft- und Raumfahrt / DLR (2000) Y1 - 2000 SN - 0937-0420 SP - 26 EP - 27 ER - TY - JOUR A1 - Hoffschmidt, Bernhard T1 - Das Solar-Institut Jülich an der Fachhochschule Aachen JF - Regenerative Energien in Deutschland und in Polen : Aspekte im Hinblick auf den EU-Beitritt Polens ; 6./7. Mai 2004, Lodz/Polen ; Tagungsband / VDI-Gesellschaft Energietechnik. 1. - Aufl. Y1 - 2004 SN - 3-931384-47-0 SP - 277 EP - 280 PB - VDI-Verl. CY - Düsseldorf ER - TY - JOUR A1 - Hoffschmidt, Bernhard T1 - Jenseits von Spanien. Das Solarthermische Versuchs- und Demonstrationskraftwerk Jülich (STJ) JF - DLR-Nachrichten (2008) Y1 - 2008 SN - 0937-0420 N1 - Sonderheft Energie SP - 38 EP - 39 ER - TY - JOUR A1 - Hoffmann, Ulrich A1 - Schermutzki, Margret A1 - Winckelmann-Schlieper, Katja T1 - Kompetenzbasierte Verzahnung von berufspraktischem und wissenschaftlichem Lernen : Der Studiengang Prozesstechnik der FH Aachen JF - Berufsbildung in Wissenschaft und Praxis (BWP). 39 (2010), H. 2 Y1 - 2010 SN - 0341-4515 SP - 32 EP - 36 ER - TY - JOUR A1 - Hoffmann, Ulrich T1 - Neue Wege in die Hochschule – Beispiel des berufsbegleitenden Studienganges Prozesstechnik der FH Aachen und der Rhein-Erft Akademie JF - HIS: Forum Hochschule. 2008 (2008), H. F14 Y1 - 2008 SN - 1863-5563 SP - 130 EP - 138 ER - TY - JOUR A1 - Hoffmann, C. P. A1 - Lindemann, Markus A1 - Zimmermann, Hans-Dieter T1 - Logistik-Ressourcen im World Wide Web JF - Wirtschaftsinformatik. Vol. 40 (1998), iss. 3 Y1 - 1998 SN - 0937-6429 SP - 245 EP - 250 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 - JOUR A1 - Hoeveler, Bastian A1 - Janser, Frank A1 - Bindewald, Thorsten A1 - Gebhardt, Andreas T1 - Entwurf, Fertigung und Untersuchung eines Windkanalmodells eines innovativen, senkrechtstartenden Kleinflugzeuges JF - RTejournal - Forum für Rapid Technologie Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0009-2-42921 SN - 1614-0923 IS - 12 SP - 1 EP - 5 PB - Fachhochschule Aachen CY - Aachen 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 A1 - Janz, Norbert T1 - Ganzheit als schlüssiges System JF - Acquisa - Das Magazin für Marketing und Vertieb. 11 (2008), H. 1 Y1 - 2008 SN - 0938-7927 SP - 44 EP - 47 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 - Hoepner, Gert T1 - Die Erhebung aussagefähiger Daten ist kostenintensiv JF - Direkt-Marketing : Zeitschrift für Dialogmarketing und Integrierte Kommunikation (2006) Y1 - 2006 SN - 0946-0446 N1 - Nebentitel: Direct marketing SP - 15 EP - 15 ER - TY - JOUR A1 - Hoepner, Gert T1 - Alumni-Arbeit an der FH Aachen JF - Dokumentation / 11. Konferenz der Alumni-Organisationen 12.- 14. Mai 2006, Fachhochschule Aachen Y1 - 2006 SN - 3-938048-07-7 N1 - Alumni-Schriftenreihe ; 18. Konferenz der Alumni-Organisationen <11, 2006, Aachen> SP - 7 EP - 17 PB - alumni-clubs.net CY - Siegen ER - TY - JOUR A1 - Hoepner, Gert T1 - Ihr Statement bitte : [Vertrauen der Kunden] JF - direkt plus (2009) Y1 - 2009 SP - 34 ER - TY - JOUR A1 - Hoepner, Gert T1 - City-Cards vor neuem Boom - Erfolgsfaktoren regionaler Mehrwertesysteme JF - Direkt-Marketing : Zeitschrift für Dialogmarketing und Integrierte Kommunikation (2008) Y1 - 2008 SN - 0946-0446 SP - 62 EP - 65 ER -