TY - CHAP A1 - Pfaff, Raphael A1 - Melcher, Karin A1 - Franzen, Julian T1 - Rare event simulation to optimise maintenance intervals of safety critical redundant subsystems T2 - Proceedings of the European Conference of the PHM Society Y1 - 2018 VL - 4 IS - 1 SP - 1 EP - 6 ER - TY - JOUR A1 - Pfaff, Raphael A1 - Enning, Manfred A1 - Sutter, Stefan T1 - A risk‑based approach to automatic brake tests for rail freight service: incident analysis and realisation concept JF - SN Applied Sciences N2 - This study reviews the practice of brake tests in freight railways, which is time consuming and not suitable to detect certain failure types. Public incident reports are analysed to derive a reasonable brake test hardware and communication architecture, which aims to provide automatic brake tests at lower cost than current solutions. The proposed solutions relies exclusively on brake pipe and brake cylinder pressure sensors, a brake release position switch as well as radio communication via standard protocols. The approach is embedded in the Wagon 4.0 concept, which is a holistic approach to a smart freight wagon. The reduction of manual processes yields a strong incentive due to high savings in manual labour and increased productivity. KW - Freight rail KW - Brake test KW - Incident analysis KW - Train composition KW - Brake set-up Y1 - 2022 U6 - https://doi.org/10.1007/s42452-022-05007-x SN - 2523-3971 N1 - Corresponding author: Raphael Pfaff VL - 4 IS - 4 SP - 1 EP - 14 PB - Springer CY - Cham ER - TY - CHAP A1 - Shahidi, Parham A1 - Pfaff, Raphael A1 - Enning, Manfred T1 - The connected wagon - a concept for the integration of vehicle side sensors and actors with cyber physical representation for condition based maintenance T2 - First International Conference on Rail Transportation Y1 - 2017 N1 - 2017 ICRT; International Conference on Rail Transportation <1, 2017, Chengdu, China> SP - 1 EP - 8 ER - TY - CHAP A1 - Pfaff, Raphael A1 - Schmidt, B. D. A1 - Enning, Manfred T1 - Towards inclusion of the freight rail system in the industrial internet of things - Wagon 4.0 T2 - Stephenson Conference, London, March 2017 Y1 - 2017 N1 - IMechE Stephenson Conference <2017, London, United Kingdom> SP - 1 EP - 10 ER - TY - THES A1 - Pfaff, Raphael T1 - Modelling of nonlinear systems using piecewise defined models Y1 - 2006 N1 - Coventry, Univ., Masterarbeit, 2006 ER - TY - CHAP A1 - Bücking, Henrik A1 - Pfaff, Raphael A1 - Dirksmeier, Roger T1 - Sensor positioning and thermal model for condition monitoring of pressure gas reservoirs in vehicles T2 - Proceedings of the Fourth European Conference of the Prognostics and Health Management Society, Utrecht, Netherlands, 2018 Y1 - 2018 ER - TY - CHAP A1 - Pfaff, Raphael A1 - Moshiri, Amir A1 - Reich, Alexander A1 - Gäbel, Markus T1 - Modelling of the effect of sanding on the wheel-rail adhesion area T2 - First International Conference on Rail Transportation Y1 - 2017 N1 - 2017 ICRT; International Conference on Rail Transportation <1, 2017, Chengdu, China> SP - 1 EP - 7 ER - TY - THES A1 - Pfaff, Raphael T1 - Automated processing of the ISL Doppler images Y1 - 2007 N1 - Hagen, Fernuniv., Bachelorarbeit, 2007 ER - TY - CHAP A1 - Pfaff, Raphael A1 - Burnham, Keith J. T1 - On abstraction and interpretability: a behavioural perspective T2 - 19th International Conference on Systems Engineering 2008 : ICSENG '08 : 19 - 21 Aug. 2008, University of Nevada, Las Vegas, Nevada Y1 - 2008 SN - 978-0-7695-3331-5 ; 978-0-7695-2719-2 SP - 89 EP - 94 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Bernau, C. R. A1 - Knödler, Matthias A1 - Emonts, Jessica A1 - Jäpel, Ronald Colin A1 - Buyel, Johannes Felix T1 - The use of predictive models to develop chromatography-based purification processes JF - Frontiers in Bioengineering and Biotechnology N2 - Chromatography is the workhorse of biopharmaceutical downstream processing because it can selectively enrich a target product while removing impurities from complex feed streams. This is achieved by exploiting differences in molecular properties, such as size, charge and hydrophobicity (alone or in different combinations). Accordingly, many parameters must be tested during process development in order to maximize product purity and recovery, including resin and ligand types, conductivity, pH, gradient profiles, and the sequence of separation operations. The number of possible experimental conditions quickly becomes unmanageable. Although the range of suitable conditions can be narrowed based on experience, the time and cost of the work remain high even when using high-throughput laboratory automation. In contrast, chromatography modeling using inexpensive, parallelized computer hardware can provide expert knowledge, predicting conditions that achieve high purity and efficient recovery. The prediction of suitable conditions in silico reduces the number of empirical tests required and provides in-depth process understanding, which is recommended by regulatory authorities. In this article, we discuss the benefits and specific challenges of chromatography modeling. We describe the experimental characterization of chromatography devices and settings prior to modeling, such as the determination of column porosity. We also consider the challenges that must be overcome when models are set up and calibrated, including the cross-validation and verification of data-driven and hybrid (combined data-driven and mechanistic) models. This review will therefore support researchers intending to establish a chromatography modeling workflow in their laboratory. KW - biopharmaceutical production process KW - Data-driven models KW - downstream processing design KW - experiment quality KW - hybrid model validation Y1 - 2022 U6 - https://doi.org/10.3389/fbioe.2022.1009102 SN - 2296-4185 (online-ressource) IS - 10 PB - Frontiers Media CY - Lausanne ER -