TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Error Corrected Impedance Measurements with a Network Analyzer Y1 - 1994 N1 - 1994 Conference on Precision Electromagnetic Measurements digest : 27 June - 1 July 1994, Boulder, Colorado, USA / Organized by National Institute of Standards and Technology. Ed. by Edie DeWeese SP - 125 EP - 126 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - A Generalization of the Txx Network Analyzer Self-Calibration Procedure JF - Conference proceedings : monday 24th to thursday 27th august 1992, Helsinki University of Technology, Espoo, Finland ; [the international conference and exhibition designed for the Microwave Community]. Vol. 2 Y1 - 1992 SN - 0-946821-77-1 N1 - European Microwave Conference <22, 1992, Espoo> ; Teknillinen Korkeakoulu SP - 907 EP - 912 PB - Microwave Exhibitions and Publishers CY - Tunbridge Wells 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 - 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 - 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 - 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 - 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 - 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 - 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 - http://dx.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 - 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 - http://dx.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 -